Patent Publication Number: US-11656249-B2

Title: Current sensor with shielding for noise suppression

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation application of International Patent Application No. PCT/JP2019/001752 filed on Jan. 22, 2019, which designated the U.S. and claims the benefit of priority from Japanese Patent Application No. 2018-052959 filed on Mar. 20, 2018. The entire disclosures of all of the above applications are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a current sensor to detect a measurement current to be measured. 
     BACKGROUND 
     A current detection system, such as a current sensor, generally detects a current by converting a magnetic field caused with a current flowing through a bus bar into an electric signal. 
     SUMMARY 
     The present disclosure describes a current sensor including an electrical-conduction member, a magnetoelectric converter and a shield. The shield includes a first shield and a second shield each having a plate shape, and the first shield and the second shield are arranged such that surfaces are opposed to and spaced away from each other. A part of the electrical-conduction member and the magnetoelectric converter are located between the surface of the first shield and the surface of the second shield. The part of the electrical-conduction member located between the first shield and the second shield extends in an extension direction that is along the surface of the first shield. The first shield and the second shield each have a center part and opposite end parts on opposite sides of the center part in the extension direction. The center part of at least one of the first shield and the second shield has a length greater than lengths of the opposite end parts of the at least one of the first shield and the second shield in a lateral direction that is along the surface of the first shield and perpendicular to the extension direction. The magnetoelectric converter is located between the opposite end parts of the first and second shields in the extension direction. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Objects, features and advantages of the present disclosure will become more apparent from the following detailed description made with reference to the accompanying drawings, in which: 
         FIG.  1    is a block diagram for explaining an in-vehicle system; 
         FIG.  2    is a perspective view of a first current sensor; 
         FIG.  3    is an exploded perspective view of the first current sensor; 
         FIG.  4    illustrates diagrams showing the first current sensor; 
         FIG.  5    illustrates diagrams showing the first current sensor; 
         FIG.  6    illustrates diagrams showing a wiring board; 
         FIG.  7    is a block diagram for explaining a sensing unit; 
         FIG.  8    illustrates diagrams showing an electrical-conduction bus bar; 
         FIG.  9    illustrates diagrams showing a first shield; 
         FIG.  10    illustrates diagrams showing a second shield; 
         FIG.  11    illustrates diagrams showing a sensor housing; 
         FIG.  12    illustrates diagrams for explaining a board support pin and a board adhesion pin; 
         FIG.  13    is a cross-sectional view along a line XIII-XIII shown in (b) of  FIG.  12   ; 
         FIG.  14    illustrates diagrams for explaining a shield support pin and a shield adhesion pin; 
         FIG.  15    is a cross-sectional view along a line XV-XV shown in (b) of  FIG.  14   ; 
         FIG.  16    is a perspective view of two individual sensors; 
         FIG.  17    is a perspective view of a wiring case; 
         FIG.  18    is a perspective view for explaining assembling of the individual sensor to the wiring case; 
         FIG.  19    is a perspective view of a second current sensor; 
         FIG.  20    illustrates diagrams showing the wiring case; 
         FIG.  21    illustrates diagrams showing the wiring case; 
         FIG.  22    illustrates diagrams showing the second current sensor; 
         FIG.  23    illustrates diagrams showing the second current sensor; 
         FIG.  24    illustrates diagrams for explaining magnetic saturation of the first shield; 
         FIG.  25    illustrates diagrams showing a result of magnetic saturation simulation; 
         FIG.  26    illustrates diagrams for explaining the second shield according to a second embodiment; 
         FIG.  27    is a schematic diagram for explaining a magnetic field to transmit a shield; 
         FIG.  28    illustrates diagrams showing a modification of the shield; 
         FIG.  29    illustrates diagrams showing another modification of the shield; 
         FIG.  30    is a perspective view of a first current sensor according to a third embodiment; 
         FIG.  31    is a cross-sectional view along a line XXXI-XXXI shown in  FIG.  30   ; 
         FIG.  32    illustrates diagrams for explaining a fixing form of the first current sensor; 
         FIG.  33    illustrates diagrams showing arrangement of a magnetoelectric converter and the electrical-conduction bus bar according to a fourth embodiment; 
         FIG.  34    illustrates diagrams for explaining output change of the magnetoelectric converter; 
         FIG.  35    is a block diagram for explaining a sensing unit according to the fourth embodiment; 
         FIG.  36    is a block diagram showing a difference circuit; 
         FIG.  37    is a schematic diagram for explaining shielding performance of a shield according to a fifth embodiment; 
         FIG.  38    is a schematic diagram for explaining the shielding performance of a shield; 
         FIG.  39    illustrates diagrams showing another modification of the shield; 
         FIG.  40    illustrates diagrams showing another modification of the shield; 
         FIG.  41    is a perspective view showing a modification of the second current sensor; 
         FIG.  42    illustrates diagrams showing another modification of the second current sensor; 
         FIG.  43    illustrates diagrams showing another modification of the second current sensor; 
         FIG.  44    is a perspective view showing assembling of an individual sensor to a wiring case; and 
         FIG.  45    illustrates diagrams for explaining types of detection form. 
     
    
    
     DETAILED DESCRIPTION 
     According to an embodiment of the present disclosure, a current sensor includes an electrical-conduction member, a magnetoelectric converter and a shield. The electrical-conduction member allows a measurement current to be measured to flow therein. The magnetoelectric converter converts a measurement magnetic field caused by a flow of the measurement current into an electric signal. The shield restricts an electromagnetic noise into the magnetoelectric converter. The shield includes a first shield and a second shield each having a plate shape, and the first shield and the second shield are arranged such that surfaces are opposed to and spaced away from each other. A part of the electrical-conduction member and the magnetoelectric converter are located between the surface of the first shield and the surface of the second shield. The part of the electrical-conduction member located between the first shield and the second shield extends in an extension direction that is along the surface of the first shield. The first shield and the second shield each have a center part and opposite end parts on opposite sides of the center part in the extension direction. The center part of at least one of the first shield and the second shield has a length greater than lengths of the opposite end parts of the at least one of the first shield and the second shield in a lateral direction that is along the surface of the first shield and perpendicular to the extension direction. The magnetoelectric converter is located between the opposite end parts of the first and second shields in the extension direction. 
     In such a configuration, in the at least one of the first shield and the second shield, the lengths of the opposite end parts is shorter than that of the center part in the lateral direction. Therefore, the electromagnetic noise less enter the opposite end parts than the center part. As such, the electromagnetic noise less permeates from one of the opposite end parts to the other of the opposite end parts via the center part in the extension direction. For this reason, the center part of the at least one of the first shield and the second shield is less likely to be magnetically saturated, and leakage of the electromagnetic noise from the center part of the at least one of the first shield and the second shield can be suppressed. 
     In the above configuration, the magnetoelectric converter is located between the opposite end parts of the first and second shields in the extension direction. In other words, the magnetoelectric converter is located between the center part of the first shield and the center part of the second shield. Therefore, it is less likely that electromagnetic noise leaked from the center part due to the magnetic saturation at the center part of the at least one of the first shield and the second shield will enter the magnetoelectric converter. As a result, the degradation of accuracy in the measurement current detection can be suppressed. 
     Hereinafter, embodiments of the present disclosure will be further described with reference to the drawings. 
     First Embodiment 
     &lt;In-Vehicle System&gt; 
     First, an in-vehicle system  100  to which a current sensor is applied will be described. The in-vehicle system  100  forms a hybrid system. As shown in  FIG.  1   , the in-vehicle system  100  has a battery  200 , a power converter  300 , a first motor  400 , a second motor  500 , an engine  600 , and a power divider  700 . 
     The in-vehicle system  100  has multiple ECUs.  FIG.  1    illustrates a battery ECU  801  and an MG ECU  802  as representatives of the multiple ECUs. The multiple ECUs mutually transmit and receive a signal(s) via a bus wiring  800 , and perform cooperative control on a hybrid vehicle. With this cooperative control, regeneration and power running of the first motor  400 , power generation of the second motor  500 , and output of the engine  600  and the like are controlled in correspondence with a SOC of the battery  200 . SOC is an abbreviation for a state of charge. ECU is an abbreviation for an electronic control unit. 
     Note that the ECU has at least one calculation processing unit (CPU), and at least one memory device (MMR) as a storage medium to hold a program and data. The ECU is provided with a microcomputer having a computer-readable storage medium. The storage medium is a non-transitory substantive storage medium to non-temporarily hold a computer-readable program. The storage medium may be provided by a semiconductor memory, a magnetic disk or the like. Hereinafter, the constituent elements of the in-vehicle system  100  will be individually summarized. 
     The battery  200  has multiple rechargeable batteries. The multiple rechargeable batteries form a serially-connected battery stack. As a rechargeable battery, a lithium ion rechargeable battery, a nickel-metal hydride rechargeable battery, an organic radical battery and the like may be employed. 
     The rechargeable battery generates an electromotive voltage by chemical reaction. The rechargeable battery has a property that deterioration accelerates when the charge amount is too large or too small. In other words, the rechargeable battery has a property that deterioration accelerates when the SOC is overcharge or overdischarge. 
     The SOC of the battery  200  corresponds to the SOC of the above-described battery stack. The SOC of the battery stack is the total sum of the SOCs of the multiple rechargeable batteries. The overcharge and overdischarge of the SOC of the battery stack can be avoided by the above-described cooperative control. On the other hand, the overcharge and overdischarge of the respective SOCs of the multiple rechargeable batteries can be avoided by equalization processing of equalizing the respective SOCs of the multiple rechargeable batteries. 
     The equalization processing is performed by individually charging/discharging the multiple rechargeable batteries. The battery  200  includes a switch to individually charge/discharge the multiple rechargeable batteries. Further, the battery  200  includes a voltage sensor, a temperature sensor and the like to detect the respective SOCs of the multiple rechargeable batteries. The battery ECU  801  controls to open and close the switch based on outputs from these sensors and a first current sensor  11  to be described later. With this configuration, the respective SOCs of the multiple rechargeable batteries are equalized. 
     The power converter  300  performs power conversion between the battery  200  and the first motor  400 . Further, the power converter  300  also performs power conversion between the battery  200  and the second motor  500 . The power converter  300  converts direct current power of the battery  200  into alternating current power at a voltage level appropriate to power running of the first motor  400  and the second motor  500 . The power converter  300  converts alternating current power generated by power generation with the first motor  400  and the second motor  500  into direct current power at a voltage level appropriate to charging of the battery  200 . The power converter  300  will be described in detail later. 
     The first motor  400 , the second motor  500 , and the engine  600  are connected to the power divider  700 . The first motor  400  is directly connected to an output shaft of a hybrid vehicle, which is not illustrated. The rotational energy of the first motor  400  is transmitted via the output shaft to a running wheel. On the contrary, the rotational energy of the running wheel is transmitted via the output shaft to the first motor  400 . 
     Power running of the first motor  400  is performed with the alternating current power supplied from the power converter  300 . Rotational energy generated by the power running is distributed with the power divider  700  to the engine  600  and the output shaft of the hybrid vehicle. With this configuration, cranking of a crankshaft and application of a propulsive force to the running wheel are performed. Further, regeneration of the first motor  400  is performed with the rotational energy transmitted from the running wheel. Alternating current power generated by the regeneration is converted with the power converter  300  into direct current power and voltage-reduced. This direct current power is supplied to the battery  200 . Further, the direct current power is also supplied to various electric load mounted on the hybrid vehicle. 
     Power generation of the second motor  500  is performed with the rotational energy supplied from the engine  600 . Alternating current power generated by the power generation is converted with the power converter  300  into direct current power and voltage-reduced. This direct current power is supplied to the battery  200  and the various electric load. 
     The engine  600  generates rotational energy by combustion driving using fuel. The rotational energy is distributed via the power divider  700  to the second motor  500  and the output shaft. With this configuration, power generation of the second motor  500  and application of a propulsive force to the running wheel are performed. 
     The power divider  700  has a planetary gear mechanism. The power divider  700  has a ring gear, a planetary gear, a sun gear, and a planetary carrier. 
     The ring gear has a ring shape. Multiple teeth are formed to be arrayed in a circumferential direction respectively on an outer peripheral surface and an inner peripheral surface of the ring gear. 
     The planetary gear and the sun gear each have a disk shape. Multiple teeth are formed to be arrayed in the circumferential direction on the respective circumferential surfaces of the planetary gear and the sun gear. 
     The planetary carrier has a ring shape. Multiple planetary gears are connected to a flat surface connecting an outer peripheral surface and an inner peripheral surface of the planetary carrier. The respective flat surfaces of the planetary carrier and the planetary gear are opposite to each other. 
     The multiple planetary gears are positioned on the circumference about a rotational center of the planetary carrier. The multiple planetary gears are provided at an equal interval between adjacent gears. In the present embodiment, three planetary gears are arrayed at an interval of 120°. 
     The sun gear is provided at the center of the ring gear. The inner peripheral surface of the ring gear and the outer peripheral surface of the sun gear are opposite to each other. Three planetary gears are provided between the ring gear and the sun gear. The teeth of the respective three planetary gears are engaged with the respective teeth of the ring gear and the sun gear. With this configuration, the respective rotation of the ring gear, the rotation of the planetary gears, the rotation of the sun gear, and the rotation of the planetary carrier are mutually transmitted. 
     The output shaft of the first motor  400  is connected to the ring gear. The crankshaft of the engine  600  is connected to the planetary carrier. The output shaft of the second motor  500  is connected to the sun gear. With this configuration, the rotation speed of the first motor  400 , the rotation speed of the engine  600 , and the rotation speed of the second motor  500  are in a linear relationship in an alignment chart. 
     Torque is generated with the ring gear and the sun gear by supplying alternating current power from the power converter  300  to the first motor  400  and the second motor  500 . Torque is generated with the planetary carrier by combustion driving with the engine  600 . With this configuration, the power running and the regeneration of the first motor  400 , the power generation of the second motor  500 , and the application of a propulsive force to the running wheel, respectively, are performed. 
     The behavior of the first motor  400 , the behavior of the second motor  500 , and the behavior of the engine  600 , respectively, are subjected to cooperative control with the multiple ECUs. For example, the MG ECU  802  determines a target torque for the first motor  400  and the second motor  500  based on the physical quantities detected with the various sensors mounted on the hybrid vehicle and vehicle information inputted from other ECUs, and the like. The MG ECU  802  performs vector control so as to bring the torque, respectively generated with the first motor  400  and the second motor  500 , to the target torque. 
     &lt;Power Converter&gt; 
     Next, the power converter  300  will be described. The power converter  300  has a converter  310 , a first inverter  320 , and a second inverter  330 . The converter  310  performs a function of stepping up and down the voltage level of direct current power. The first inverter  320  and the second inverter  330  perform a function of converting direct current power into alternating current power. The first inverter  320  and the second inverter  330  perform a function of converting alternating current power into direct current power. 
     In the in-vehicle system  100 , the converter  310  boosts the direct current power of the battery  200  to a voltage level appropriate to power running of the first motor  400  and the second motor  500 . The first inverter  320  and the second inverter  330  convert the direct current power into alternating current power. The alternating current power is supplied to the first motor  400  and the second motor  500 . Further, the first inverter  320  and the second inverter  330  convert the alternating current power generated with the first motor  400  and the second motor  500  into direct current power. The converter  310  reduces the direct current power to a voltage level appropriate to charging of the battery  200 . 
     As shown in  FIG.  1   , the converter  310  is electrically connected via a first power line  301  and a second power line  302  to the battery  200 . The converter  310  is electrically connected via a third power line  303  and a fourth power line  304  to the first inverter  320  and the second inverter  330  respectively. 
     One end of the first power line  301  is electrically connected to the cathode of the battery  200 . One end of the second power line  302  is electrically connected to the anode of the battery  200 . The respective other ends of the first power line  301  and the second power line  302  are electrically connected to the converter  310 . 
     A first smoothing capacitor  305  is connected to the first power line  301  and the second power line  302 . One of two electrodes of the first smoothing capacitor  305  is connected to the third power line  303 , and the other electrode is connected to the fourth power line  304 . 
     Note that the battery  200  has a system main relay (SMR), which is not illustrated. The electric connection between the battery stack of the battery  200  and the power converter  300  is controlled by opening and closing of the system main relay. That is, continuation and interruption of power supply between the battery  200  and the power converter  300  is controlled by the opening and closing of the system main relay. 
     One end of the third power line  303  is electrically connected to a high side switch  311  of the converter  310 . One end of the fourth power line  304  is electrically connected to the other end of the second power line  302 . The respective other ends of the third power line  303  and the fourth power line  304  are electrically connected to the first inverter  320  and the second inverter  330  respectively. 
     A second smoothing capacitor  306  is connected to the third power line  303  and the fourth power line  304 . One of two electrodes of the second smoothing capacitor  306  is connected to the third power line  303 , and the other electrode is connected to the fourth power line  304 . 
     The first inverter  320  is electrically connected via first energization bus bar  341  to third energization bus bar  343  to first U phase stator coil  401  to first W phase stator coil  403  of the first motor  400 . The second inverter  330  is electrically connected via fourth energization bus bar  344  to sixth energization bus bar  346  to second U phase stator coil  501  to second W phase stator coil  503  of the second motor  500 . 
     &lt;Converter&gt; 
     The converter  310  has the high side switch  311 , a low side switch  312 , a high side diode  311   a , a low side diode  312   a , and a reactor  313 . As the high side switch  311  and the low side switch  312 , an IGBT, a power MOSFET or the like may be employed. In the present embodiment, an n-channel type IGBT is employed as the high side switch  311  and the low side switch  312 . 
     Note that when the high side switch  311  and the low side switch  312  are each provided by the MOSFET, a body diode is formed in the MOSFET. Accordingly, the high side diode  311   a  and the low side diode  312   a  may be omitted. The semiconductor device forming the converter  310  may be manufactured with a semiconductor such as Si, or a wide gap semiconductor such SiC. 
     The high side diode  311   a  is connected in anti-parallel to the high side switch  311 . That is, the cathode electrode of the high side diode  311   a  is connected to the collector electrode of the high side switch  311 . The anode electrode of the high side diode  311   a  is connected to the emitter electrode of the high side switch  311 . 
     Similarly, the low side diode  312   a  is connected in anti-parallel to the low side switch  312 . The cathode electrode of the low side diode  312   a  is connected to the collector electrode of the low side switch  312 . The anode electrode of the low side diode  312   a  is connected to the emitter electrode of the low side switch  312 . 
     As shown in  FIG.  1   , the third power line  303  is electrically connected to the collector electrode of the high side switch  311 . The emitter electrode of the high side switch  311  and the collector electrode of the low side switch  312  are connected to each other. The second power line  302  and the fourth power line  304  are electrically connected to the emitter electrode of the low side switch  312 . With this configuration, the high side switch  311  and the low side switch  312  are connected in series, in order, from the third power line  303  toward the second power line  302 . In other words, the high side switch  311  and the low side switch  312  are connected in series, in order, from the third power line  303  toward the fourth power line  304 . 
     A middle point between the high side switch  311  and the low side switch  312 , which are connected in series, is electrically connected to one end of the reactor  313  via the energization bus bar  307 . The other end of the reactor  313  is electrically connected to the other end of the first power line  301 . 
     With the above-described configuration, the direct current power of the battery  200  is supplied via the reactor  313  and the energization bus bar  307  to the middle point between the high side switch  311  and the low side switch  312 , which are connected in series. The alternating current power of the motor, converted with at least one of the first inverter  320  and the second inverter  330  into the direct current power, is supplied to the collector electrode of the high side switch  311 . The alternating current power of the motor, converted into the direct current power, is supplied via the high side switch  311 , the energization bus bar  307 , and the reactor  313 , to the battery  200 . 
     In this manner, the direct current power inputted to or outputted from the battery  200  flows through the energization bus bar  307 . When the flowing physical quantities are limited, the direct current inputted to or outputted from the battery  200  flows through the energization bus bar  307 . 
     The high side switch  311  and the low side switch  312  of the converter  310  are controlled to be open and closed with the MG ECU  802 . The MG ECU  802  generates a control signal and outputs the control signal to a gate driver  803 . The gate driver  803  amplifies the control signal and outputs the control signal to the gate electrode of the switch. With this configuration, the MG ECU  802  steps up or down the voltage level of the direct current power inputted into the converter  310 . 
     The MG ECU  802  generates a pulse signal as a control signal. The MG ECU  802  controls the voltage stepping up and down levels of the direct current power by controlling the on duty ratio and frequency of the pulse signal. The voltage stepping up and down levels are determined in correspondence with the above-described target torque and the SOC of the battery  200 . 
     When the direct current power of the battery  200  is stepped up, the MG ECU  802  alternately opens and closes the high side switch  311  and the low side switch  312  respectively. For this purpose, the MG ECU  802  inverts the voltage level of the control signal outputted to the high side switch  311  and the low side switch  312 . 
     When a high level signal is inputted into the gate electrode of the high side switch  311 , a low level signal is inputted into the gate electrode of the low side switch  312 . In this case, the direct current power of the battery  200  is supplied via the reactor  313  and the high side switch  311  to the first inverter  320  and the second inverter  330 . At this time, electrical energy is stored in the reactor  313  by flow of the current. Further, electric charge is stored in the second smoothing capacitor  306 . The second smoothing capacitor  306  is charged. 
     When a low level signal is inputted into the gate electrode of the high side switch  311 , a high level signal is inputted into the gate electrode of the low side switch  312 . In this case, a closed loop passing through the first smoothing capacitor  305 , the reactor  313 , and the low side switch  312  is formed. As described above, since the electrical energy is stored in the reactor  313 , the reactor  313  attempts to pass the current. The current caused by the electrical energy in the reactor  313  flows through the above-described closed loop. 
     In this case, supply of the direct current power via the high side switch  311  to the first inverter  320  and the second inverter  330  stops. However, the second smoothing capacitor  306  is charged. Accordingly, electric power is supplied from the second smoothing capacitor  306  to the first inverter  320  and the second inverter  330 . The power supply to the first inverter  320  and the second inverter  330  is continued. 
     Thereafter, a high level signal is inputted into the high side switch  311 , while a low level signal is inputted into the low side switch  312 . At this time, the electrical energy stored in the reactor  313  is supplied, together with the direct current power of the battery  200 , as direct current power, to the first inverter  320  and the second inverter  330 . With this configuration, the direct current power of the battery  200 , stepped up in a time-average manner, is supplied to the first inverter  320  and the second inverter  330 . Further, the charging of the second smoothing capacitor  306  is recovered, and the charging amount is increased. The voltage level of the direct current power supplied from the second smoothing capacitor  306  to the first inverter  320  and the second inverter  330  is raised. 
     When the direct current power supplied from at least one of the first inverter  320  and the second inverter  330  is stepped down, the MG ECU  802  fixes the control signal outputted to the low side switch  312  at the low level. At the same time, the MG ECU  802  switches the control signal outputted to the high side switch  311  to the high level and the low level sequentially. 
     When a high level signal is inputted into the gate electrode of the high side switch  311 , the direct current power of at least one of the first inverter  320  and the second inverter  330  is supplied via the high side switch  311  and the reactor  313  to the battery  200 . 
     When a low level signal is inputted into the gate electrode of the high side switch  311 , the direct current power of at least one of the first inverter  320  and the second inverter  330  is not supplied to the battery  200 . As a result, the direct current power reduced in a time-average manner is supplied to the battery  200 . 
     To be more exact, when a high level signal is inputted into the gate electrode of the high side switch  311  as described above, the first smoothing capacitor  305  is charged. Electrical energy is stored in the reactor  313 . Thereafter, when a low level signal is inputted into the gate electrode of the high side switch  311  and the output voltage and time constant of the second smoothing capacitor  306  and those of the battery  200  are different, charging/discharging is performed between the second smoothing capacitor  306  and the battery  200 . Further, a diode, which is not illustrated, connects the first power line  301  and the second power line  302 . The anode electrode of the diode is connected to the second power line  302 , and the cathode electrode of the diode is connected to the first power line  301 . Accordingly, a closed loop passing through the diode, the reactor  313 , and the first smoothing capacitor  305  is formed. The current caused by the electrical energy in the reactor  313  flows through the closed loop. 
     &lt;Inverter&gt; 
     The first inverter  320  has first switch  321  to sixth switch  326 , and first diode  321   a  to sixth diode  326   a . As the first switch  321  to the sixth switch  326 , an IGBT, a power MOSFET or the like may be employed. In the present embodiment, an n-channel type IGBT is employed as the first switch  321  to the sixth switch  326 . When the MOSFET is employed as these switches, the above-described diode may be omitted. The semiconductor device forming the first inverter  320  may be manufactured with a semiconductor such as Si, or a wide gap semiconductor such as SiC. 
     The first diode  321   a  to the sixth diode  326   a  corresponding to the first switch  321  to the sixth switch  326  are connected in anti-parallel. That is, assuming that k is a natural number of 1 to 6, the cathode electrode of the k-th diode is connected to the collector electrode of the k-th switch. The anode electrode of the k-th diode is connected to the emitter electrode of the k-th switch. 
     The first switch  321  and the second switch  322  are connected in series, in order, from the third power line  303  toward the fourth power line  304 . The first switch  321  and the second switch  322  form a first U phase leg. One end of the first energization bus bar  341  is connected to a middle point between the first switch  321  and the second switch  322 . The other end of the first energization bus bar  341  is connected to the first U phase stator coil  401  of the first motor  400 . 
     The third switch  323  and the fourth switch  324  are connected in series, in order, from the third power line  303  toward the fourth power line  304 . The third switch  323  and the fourth switch  324  form a first V phase leg. One end of the second energization bus bar  342  is connected to a middle point between the third switch  323  and the fourth switch  324 . The other end of the second energization bus bar  342  is connected to the first V phase stator coil  402  of the first motor  400 . 
     The fifth switch  325  and the sixth switch  326  are connected in series, in order, from the third power line  303  toward the fourth power line  304 . The fifth switch  325  and the sixth switch  326  form a first W phase leg. One end of the third energization bus bar  343  is connected to a middle point between the fifth switch  325  and the sixth switch  326 . The other end of the third energization bus bar  343  is connected to the first W phase stator coil  403  of the first motor  400 . 
     The second inverter  330  has a similar configuration to that of the first inverter  320 . The second inverter  330  has seventh switch  331  to twelfth switch  336  and seventh diode  331   a  to twelfth diode  336   a.    
     The seventh diode  331   a  to the twelfth diode  336   a  corresponding to the seventh switch  331  to the twelfth switch  336  are inversely parallel-connected. Assuming that n is a natural number of 7 to 12, the cathode electrode of the n-th diode is connected to the collector electrode of the n-th switch. The anode electrode of the n-th diode is connected to the emitter electrode of the n-th switch. 
     The seventh switch  331  and the eighth switch  332  are connected in series between the third power line  303  and the fourth power line  304 , and form a second U phase leg. One end of the fourth energization bus bar  344  is connected to a middle point between the seventh switch  331  and the eighth switch  332 . The other end of the fourth energization bus bar  344  is connected to the second U phase stator coil  501  of the second motor  500 . 
     The ninth switch  333  and the tenth switch  334  are connected in series between the third power line  303  and the fourth power line  304 , and form a second V phase leg. One end of the fifth energization bus bar  345  is connected to a middle point between the ninth switch  333  and the tenth switch  334 . The other end of the fifth energization bus bar  345  is connected to the second V phase stator coil  502  of the second motor  500 . 
     The eleventh switch  335  and the twelfth switch  336  are connected in series between the third power line  303  and the fourth power line  304 , and form a second W phase leg. One end of the sixth energization bus bar  346  is connected to a middle point between the eleventh switch  335  and the twelfth switch  336 . The other end of the sixth energization bus bar  346  is connected to the second W phase stator coil  503  of the second motor  500 . 
     As described above, the first inverter  320  and the second inverter  330  respectively have three phase legs corresponding to the respective U phase to W phase stator coils of the motor. The control signal of the MG ECU  802 , amplified with the gate driver  803 , is inputted into the gate electrode of the switch of the respective three phase legs. 
     When the motor is subjected to power running, the respective switches are PWM controlled by output of the control signal from the MG ECU  802 . With this configuration, a three-phase alternating current is generated with the inverter. When the motor generates power, the MG ECU  802  stops, for example, output of the control signal. The alternating current power generated by power generation with the motor passes through the diode. As a result, the alternating current power is converted into direct current power. 
     The above-described alternating current power inputted to or outputted from the first motor  400  flows through the first energization bus bar  341  to the third energization bus bar  343  connecting the first inverter  320  to the first motor  400 . Similarly, the alternating current power inputted to or outputted from the second motor  500  flows through the fourth energization bus bar  344  to the sixth energization bus bar  346  connecting the second inverter  330  to the second motor  500 . 
     When the flowing physical quantities are limited, the alternating current inputted to or outputted from the first motor  400  flows through the first energization bus bar  341  to the third energization bus bar  343 . The alternating current inputted to or outputted from the second motor  500  flows through the fourth energization bus bar  344  to the sixth energization bus bar  346 . 
     &lt;Current Sensor&gt; 
     Next, a current sensor applied to the in-vehicle system  100  described above will be described. 
     As a current sensor, the first current sensor  11 , a second current sensor  12 , and a third current sensor  13  are provided. The first current sensor  11  detects a current which flows through the converter  310 . The second current sensor  12  detects a current which flows through the first motor  400 . The third current sensor  13  detects a current which flows through the second motor  500 . 
     The first current sensor  11  is provided on the energization bus bar  307 . As described above, the direct current inputted to or outputted from the battery  200  flows through the energization bus bar  307 . The first current sensor  11  detects the direct current. 
     The direct current detected with the first current sensor  11  is inputted into the battery ECU  801 . The battery ECU  801  monitors the SOC of the battery  200  based on the direct current detected with the first current sensor  11 , the voltage of the battery stack detected with a voltage sensor, which is not illustrated, and the like. 
     The second current sensor  12  is provided on the first energization bus bar  341  to the third energization bus bar  343 . As described above, the alternating current inputted to or outputted from the first motor  400  flows through the first energization bus bar  341  to the third energization bus bar  343 . The second current sensor  12  detects the alternating current. 
     The alternating current detected with the second current sensor  12  is inputted into the MG ECU  802 . The MG ECU  802  vector-controls the first motor  400  based on the alternating current detected with the second current sensor  12 , the rotation angle of the first motor  400  detected with a rotation angle sensor, which is not illustrated, and the like. 
     The third current sensor  13  is provided on the fourth energization bus bar  344  to the sixth energization bus bar  346 . As described above, the alternating current inputted to or outputted from the second motor  500  flows through the fourth energization bus bar  344  to the sixth energization bus bar  346 . The third current sensor  13  detects the alternating current. 
     The alternating current detected with the third current sensor  13  is inputted into the MG ECU  802 . The MG ECU  802  vector-controls the second motor  500  based on the alternating current detected with the third current sensor  13 , the rotation angle of the second motor  500  detected with a rotation angle sensor, which is not illustrated, and the like. 
     Note that the first U phase stator coil  401 , the first V phase stator coil  402 , and the first W phase stator coil  403  of the first motor  400  are star-connected. Similarly, the second U phase stator coil  501 , the second V phase stator coil  502 , and the second W phase stator coil  503  of the second motor  500  are star-connected. Accordingly, by detecting the currents in the two of the three phase stator coils, it is possible to detect the current in the remaining one phase stator coil. 
     A structure where these three phase stator coils are delta-connected may be employed. In this structure, by detecting the currents in the two of the three phase stator coils, it is possible to detect the current in the remaining one phase stator coil. 
     The second current sensor  12  is provided on two of the first energization bus bar  341  to the third energization bus bar  343  connected to the first U phase stator coil  401  to the first W phase stator coil  403 . More specifically, the second current sensor  12  is provided on the first energization bus bar  341  and the second energization bus bar  342 . 
     Accordingly, the second current sensor  12  detects the current which flows through the first U phase stator coil  401  and the current which flows through the first V phase stator coil  402 . The MG ECU  802  detects the current which flows through the first W phase stator coil  403  based on the current which flows through the first U phase stator coil  401  and the current which flows through the first V phase stator coil  402 . 
     Similarly, the third current sensor  13  is provided on two of the fourth energization bus bar  344  to the sixth energization bus bar  346  connected to the second U phase stator coil  501  to the second W phase stator coil  503 . More specifically, the third current sensor  13  is provided on the fourth energization bus bar  344  and the fifth energization bus bar  345 . 
     Accordingly, the third current sensor  13  detects the current which flows through the second U phase stator coil  501  and the current which flows through the second V phase stator coil  502 . The MG ECU  802  detects the current which flows through the second W phase stator coil  503  based on the current which flows through the second U phase stator coil  501  and the current which flows through the second V phase stator coil  502 . 
     The above-described direct current inputted to or outputted from the battery  200  and the alternating currents inputted to or outputted from the first motor  400  and the second motor  500  respectively correspond to a measurement current to be measured. The magnetic field generated by flow of these currents corresponds to a measured magnetic field to be measured. 
     &lt;First Current Sensor&gt; 
     As described above, the first current sensor  11  is provided on the energization bus bar  307 . The energization bus bar  307  is divided into a part adjacent to the reactor  313  and a part adjacent to the high side switch  311  (low side switch  312 ). The first current sensor  11  is provided on the energization bus bar  307 , in a form of bridging the divided parts of the energization bus bar  307 . With this configuration, the current which flows through the energization bus bar  307 , i.e., the direct current inputted to or outputted from the battery  200  flows through the first current sensor  11 . 
     The configuration where the energization bus bar  307  is divided into the part adjacent to the reactor  313  and the part adjacent to the high side switch  311  is merely an example. For example, when the energization bus bar  307  is not divided and connected only to the high side switch  311  side, the first current sensor  11  bridges the reactor  313  and the energization bus bar  307 . 
     As shown in  FIG.  2    to  FIG.  5   , the first current sensor  11  has a wiring board  20 , an electrical-conduction bus bar  30 , a shield  40 , and a sensor housing  50 . The electrical-conduction bus bar  30  bridges the above-described energization bus bar  307 . Accordingly, the direct current flows through the electrical-conduction bus bar  30 . The electrical-conduction bus bar  30  corresponds to an electrical-conduction member. 
     In  FIG.  4   , (a) shows a top view of the first current sensor  11 ; (b) shows a front view of the first current sensor  11 ; and (c) shows a bottom view of the first current sensor  11 . In  FIG.  5   , (a) shows a front view of the first current sensor  11 ; (b) shows a side view of the first current sensor  11 ; and (c) shows a rear view of the first current sensor  11 . Note that (b) of  FIG.  4    and (a) of  FIG.  5    show the same figure. 
     As clearly indicated in these figures, a part of the electrical-conduction bus bar  30  is insert-molded in the sensor housing  50 . The wiring board  20  and the shield  40  are disposed in the sensor housing  50 . The sensor housing  50  is made of an insulating resin material. 
     The wiring board  20  is fixed in the sensor housing  50  to be opposed to the part of the electrical-conduction bus bar  30  insert-molded in the sensor housing  50 . A magnetoelectric converter  25 , which will be described later, is mounted on the opposing part of the wiring board  20  to the electrical-conduction bus bar  30 . The magnetoelectric converter  25  converts a magnetic field caused by the direct current which flows through the electrical-conduction bus bar  30  into an electric signal. 
     The shield  40  has a first shield  41  and a second shield  42 . The first shield  41  and the second shield  42  are fixed, away from each other, to the sensor housing  50 . The respective mutually opposing parts of the wiring board  20  and the electrical-conduction bus bar  30  are positioned between the first shield  41  and the second shield  42 . 
     The first shield  41  and the second shield  42  are made of a material with higher magnetic permeability than that of the sensor housing  50 . Accordingly, electromagnetic noise (external noise), which attempts to permeate from the outside of the first current sensor  11  into the inside, actively attempts to pass through the first shield  41  and the second shield  42 . With this configuration, the input of the external noise into the magnetoelectric converter  25  is suppressed. 
     A connection terminal  60  shown in  FIG.  4    is insert-molded in the sensor housing  50 . The connection terminal  60  is electrically and mechanically connected to the wiring board  20  with solder  61 . The connection terminal  60  is electrically connected via a wire harness or the like to the battery ECU  801 . The electric signal converted with the magnetoelectric converter  25  is inputted via the connection terminal  60 , a wire harness (not illustrated), and the like, into the battery ECU  801 . 
     Next, the constituent elements of the first current sensor  11  will be individually described in detail. In the following description, three directions in mutual orthogonal relationship are referred to as x direction, y direction, and z direction. The x direction corresponds to a lateral direction. The y direction corresponds to an extension direction. 
     &lt;Wiring Board&gt; 
     As shown in  FIG.  6   , the wiring board  20  has a flat plate shape. The wiring board  20  has a thin flat shape having a thickness in the z direction. The wiring board  20  is formed by laminating multiple insulating resin layers and conductive metal layers in the z direction. In the wiring board  20 , an opposing surface  20   a  having the largest area and a rear surface  20   b  on the rear side of the opposing surface  20   a  face in the z direction. In  FIG.  6   , (a) shows a top view of the wiring board  20 ; and (b) shows a bottom view of the wiring board  20 . 
     A first sensing unit  21  and a second sensing unit  22  shown in (a) of  FIG.  6    and in  FIG.  7    are mounted on the opposing surface  20   a  of the wiring board  20 . The first sensing unit  21  and the second sensing unit  22  each have an ASIC  23  and a filter  24 . The ASIC  23  and the filter  24  are electrically connected to each other via a wiring pattern of the wiring board  20 . The connection terminal  60  is electrically connected to the wiring pattern. ASIC is an abbreviation for application specific integrated circuit. Note that a structure where the first sensing unit  21  and the second sensing unit  22  are mounted on the rear surface  20   b  may be employed. 
     &lt;ASIC&gt; 
     The ASIC  23  has a magnetoelectric converter  25 , a processing circuit  26 , a connection pin  27 , and a resin section  28 . The magnetoelectric converter  25  and the processing circuit  26  are electrically connected to each other. One end of the connection pin  27  is electrically connected to the processing circuit  26 . The other end of the connection pin  27  is electrically and mechanically connected to the wiring board  20 . A part of the connection pin  27  including the one end, the processing circuit  26 , and the magnetoelectric converter  25  are covered with the resin section  28 . A part of the connection pin  27  including the other end is exposed from the resin section  28 . 
     The magnetoelectric converter  25  has multiple magnetoresistive effect elements having a resistance value variable in correspondence with magnetic field (transmission magnetic field) which permeates the magnetoelectric converter  25  itself. In the magnetoresistive effect element, the resistance value varies in correspondence with transmission magnetic field along the opposing surface  20   a . That is, the resistance value of the magnetoresistive effect element varies in correspondence with a component of the transmission magnetic field along the x direction and a component of the transmission magnetic field along the y direction. 
     On the other hand, the resistance value of the magnetoresistive effect element does not vary in correspondence with transmission magnetic field along the z direction. Accordingly, even when the external noise along the z direction permeates the magnetoresistive effect element, the resistance value of the magnetoresistive effect element does not vary. 
     The magnetoresistive effect element has a pinned layer, the magnetization direction of which is fixed, a free layer, the magnetization direction of which changes in correspondence with transmission magnetic field, and an intermediate layer provided between the pinned layer and the free layer. When the intermediate layer has a non-conductive property, the magnetoresistive effect element is a giant magnetoresistive effect element. When the intermediate layer has a conductive property, the magnetoresistive effect element is a tunnel magnetoresistive effect element. Note that the magnetoresistive effect element may be an anisotropic magnetoresistive effect element (AMR). Further, the magnetoelectric converter  25  may have a hall element in place of the magnetoresistive effect element. 
     The resistance value of the magnetoresistive effect element varies in accordance with angle formed with respective magnetization directions of the pinned layer and the free layer. The magnetization direction of the pinned layer is along the opposing surface  20   a . The magnetization direction of the free layer is determined based on the transmission magnetic field along the opposing surface  20   a . The resistance value of the magnetoresistive effect element is the minimum when the respective magnetization directions of the free layer and the fixed layer are in parallel. The resistance value of the magnetoresistive effect element is the maximum when the respective magnetization directions of the free layer and the fixed layer are antiparallel. 
     The magnetoelectric converter  25  has a first magnetoresistive effect element  25   a  and a second magnetoresistive effect element  25   b  as the above-described magnetoresistive effect elements. The magnetization direction of the pinned layer of the first magnetoresistive effect element  25   a  and the magnetization direction of the pinned layer of the second magnetoresistive effect element  25   b  are different by 90°. The relationship of increase and decrease of resistance value is inverted between the magnetoresistive effect element  25   a  and the second magnetoresistive effect element  25   b . When the resistance value of one of the first magnetoresistive effect element  25   a  and the second magnetoresistive effect element  25   b  is reduced, the resistance value of the other is increased by the equivalent amount to the reduced amount. 
     The magnetoelectric converter  25  have two first magnetoresistive effect elements  25   a  and two second magnetoresistive effect elements  25   b . The first magnetoresistive effect element  25   a  and the second magnetoresistive effect element  25   b  are connected in series, in order, from a power source potential toward a reference potential, to form a first half bridge circuit. The second magnetoresistive effect element  25   b  and the first magnetoresistive effect element  25   a  are connected in series, in order, from the power source potential toward the reference potential, to form a second half bridge circuit. 
     Between the two half bridge circuits, the arrangement order of the first magnetoresistive effect element  25   a  and the second magnetoresistive effect element  25   b  is inverted. Accordingly, when a middle point potential of one of the two half bridge circuits is lowered, a middle point potential of the other is raised. In the magnetoelectric converter  25 , a full bridge circuit is formed by combination of these two half bridge circuits. 
     The magnetoelectric converter  25  has, in addition to the magnetoresistive effect elements forming the above-described full bridge circuit, a differential amplifier  25   c , a feedback coil  25   d , and a shunt resistor  25   e . The middle point potentials of the two half bridge circuits are inputted into an inverted input terminal and a non-inverted input terminal of the differential amplifier  25   c . The feedback coil  25   d  and the shunt resistor  25   e  are connected in series, in order, from an output terminal of the differential amplifier  25   c  toward the reference potential. 
     With the above-described connection configuration, an output is made in correspondence with variation of the resistance values of the first magnetoresistive effect elements  25   a  and the second magnetoresistive effect elements  25   b , forming the full bridge circuit, from the output terminal of the differential amplifier  25   c . The variation of resistance value is caused by permeation of the magnetic field along the opposing surface  20   a  through the magnetoresistive effect element. The magnetic field (measurement current) caused by the current which flows through the electrical-conduction bus bar  30  permeates the magnetoresistive effect element. Accordingly, a current corresponding to the measurement current flows through the input terminal of the differential amplifier  25   c.    
     The input terminal and the output terminal of the differential amplifier  25   c  are connected to each other via a feedback circuit, which is not illustrated. With this configuration, virtual short-circuit occurs in the differential amplifier  25   c . The differential amplifier  25   c  operates so as to cause the inverted input terminal and the non-inverted input terminal to have the same potential. That is, the differential amplifier  25   c  operates such that the current which flows through the input terminal and the current which flows through the output terminal are zero. As a result, a current corresponding to the measurement current (feedback current) flows from the output terminal of the differential amplifier  25   c.    
     The feedback current flows via the feedback coil  25   d  and the shunt resistor  25   e  between the output terminal of the differential amplifier  25   c  and the reference potential. An offset magnetic field is generated in the feedback coil  25   d  by the flow of the feedback current. The offset magnetic field permeates the magnetoelectric converter  25 . With this permeation, the measurement current which permeates the magnetoelectric converter  25  is offset. The magnetoelectric converter  25  operates so as to bring the measurement current which permeates the magnetoelectric converter  25  itself and the offset magnetic field into equilibrium. 
     A feedback voltage corresponding to the current amount of the feedback current which generates the offset magnetic field is generated in a middle point between the feedback coil  25   d  and the shunt resistor  25   e . The feedback voltage is outputted as an electric signal of detection of the measurement current, to the processing circuit  26  at the subsequent stage. 
     The processing circuit  26  has an adjustment amplifier  26   a  and a threshold power source  26   b . The middle point between the feedback coil  25   d  and the shunt resistor  25   e  is connected to a non-inverted input terminal of the adjustment amplifier  26   a . The threshold power source  26   b  is connected to an inverted input terminal of the adjustment amplifier  26   a . With this configuration, a differential-amplified feedback voltage is outputted from the adjustment amplifier  26   a.    
     The respective resistance values of the first magnetoresistive effect elements  25   a  and the second magnetoresistive effect elements  25   b  forming the full bridge circuit each have a temperature-dependent property. The output of the adjustment amplifier  26   a  varies in accordance with temperature change. The processing circuit  26  has a temperature detection element (not illustrated), a nonvolatile memory to store the relationship between the temperature and the resistance value of the magnetoresistive effect element, and the like. The nonvolatile memory is electrically rewritable. The gain and offset of the adjustment amplifier  26   a  are adjusted by rewriting values stored in the nonvolatile memory. With this configuration, the variation of output of the adjustment amplifier  26   a  due to temperature change is cancelled. 
     &lt;Filter&gt; 
     The filter  24  has a resistor  24   a  and a capacitor  24   b . As shown in  FIG.  7   , a power source wiring  20   c , a first output wiring  20   d , a second output wiring  20   e , and a ground wiring  20   f , as wiring patterns, are formed on the wiring board  20 . 
     The ASIC  23  of the first sensing unit  21  is connected to the power source wiring  20   c , the first output wiring  20   d , and the ground wiring  20   f , respectively. An output terminal of the adjustment amplifier  26   a  of the ASIC  23  of the first sensing unit  21  is connected to the first output wiring  20   d.    
     The resistor  24   a  of the filter  24  of the first sensing unit  21  is provided on the first output wiring  20   d . The capacitor  24   b  connects the first output wiring  20   d  and the ground wiring  20   f . With this configuration, the filter  24  of the first sensing unit  21  forms a low-pass filter with the resistor  24   a  and the capacitor  24   b . An output from the ASIC  23  of the first sensing unit  21  is provided via the low-pass filter to the battery ECU  801 . With this configuration, an output of the first sensing unit  21 , from which high-frequency noise is eliminated, is provided to the battery ECU  801 . 
     The ASIC  23  of the second sensing unit  22  is connected to the power source wiring  20   c , the second output wiring  20   e , and the ground wiring  20   f , respectively. The output terminal of the adjustment amplifier  26   a  of the ASIC  23  of the first sensing unit  21  is connected to the second output wiring  20   e.    
     The resistor  24   a  of the filter  24  of the second sensing unit  22  is provided on the second output wiring  20   e . The capacitor  24   b  connects the second output wiring  20   e  and the ground wiring  20   f . With this configuration, the filter  24  of the second sensing unit  22  forms a low-pass filter with the resistor  24   a  and the capacitor  24   b . An output from the ASIC  23  of the second sensing unit  22  is provided via the low-pass filter to the battery ECU  801 . An output of the second sensing unit  22 , from which high-frequency noise is eliminated, is provided to the battery ECU  801 . 
     As described above, the first sensing unit  21  and the second sensing unit  22  of the present embodiment have the same configuration. The respective magnetoelectric converters  25  of the first sensing unit  21  and the second sensing unit  22  are aligned in the y direction. As described later, the magnetic field which permeates the respective magnetoelectric converter  25  of the first sensing unit  21  and the magnetic field which permeates the respective magnetoelectric converter  25  of the second sensing unit  22  are the same. 
     Accordingly, the electric signal provided from the first sensing unit  21  to the battery ECU  801  and the electric signal provided from the second sensing unit  22  to the battery ECU  801  are the same. The battery ECU  801  determines whether or not an abnormality occurs in one of the first sensing unit  21  and the second sensing unit  22  by comparing the two electric signals provided. In this manner, the first current sensor  11  according to the preset embodiment has redundancy. 
     Note that the above-described shunt resistor  25   e  may be provided in the resin section  28 , or may be provided outside of the resin section  28 . When the shunt resistor  25   e  is provided outside of the resin section  28 , the shunt resistor  25   e  is mounted on the wiring board  20 . Then the shunt resistor  25   e  is externally attached to the ASIC  23 . 
     Further, as long as at least one of these four resistors is a magnetoresistive effect element, the respective four resistors forming the full bridge circuit are not necessarily magnetoresistive effect elements. In place of the full bridge circuit, only one half bridge circuit may be formed. 
     When the above-described redundancy is not required, as the first current sensor  11 , a configuration having one of the first sensing unit  21  and the second sensing unit  22  may be employed. 
     &lt;Electrical-Conduction Bus Bar&gt; 
     The electrical-conduction bus bar  30  is made of a conductive material such as copper, brass, or aluminum. The electrical-conduction bus bar  30  may be manufactured by the following methods, for example. The electrical-conduction bus bar  30  may be manufactured by press-working a flat plate. The electrical-conduction bus bar  30  may be manufactured by integrally joining multiple flat plates. The electrical-conduction bus bar  30  may be manufactured by welding multiple flat plates. The electrical-conduction bus bar  30  may be manufactured by pouring a molten-state conductive material into a mold. The manufacturing method of the electrical-conduction bus bar  30  is not particularly limited. 
     As shown in  FIG.  8   , the electrical-conduction bus bar  30  has a thin flat shape having the thickness in the z direction. In the electrical-conduction bus bar  30 , a front surface  30   a  and a rear surface  30   b  on the rear side of the front surface  30   a , respectively, face in the z direction. In  FIG.  8   , (a) shows a top view of the electrical-conduction bus bar; and (b) shows a side view of the electrical-conduction bus bar. 
     The electrical-conduction bus bar  30  extends in the y direction. As marked off with two broken lines in  FIG.  8   , the electrical-conduction bus bar  30  has a covered part  31  covered with the sensor housing  50 , and first exposed part  32  and second exposed part  33  exposed from the sensor housing  50 . The first exposed part  32  and the second exposed part  33  are aligned via the covered part  31  in the y direction. The first exposed part  32  and the second exposed part  33  are connected integrally via the covered part  31 . 
     As shown in (b) of  FIG.  8   , the respective dimensions (thicknesses) of the covered part  31 , the first exposed part  32 , and the second exposed part  33  in the z direction are equal to each other. That is, respective distances in the z direction between the front surfaces  30   a  and the rear surfaces  30   b  of the covered part  31 , the first exposed part  32 , and the second exposed part  33 , are equal to each other. 
     A bolt hole  30   c  for electrical and mechanical connection via a bolt to the energization bus bar  307  is formed in each of the first exposed part  32  and the second exposed part  33 . The bolt hole  30   c  passes through each of the first exposed part  32  and the second exposed part  33  from the front surface  30   a  to the rear surface  30   b.    
     As described above, the energization bus bar  307  is divided into the part adjacent to the reactor  313  and the part adjacent to the high side switch  311 . An attachment hole corresponding to the bolt hole  30   c  is formed respectively in the part adjacent to the reactor  313  and in the part adjacent to the high side switch  311  of the energization bus bar  307 . 
     The attachment hole of the energization bus bar  307  in the part adjacent to the reactor  313  and the bolt hole  30   c  of the first exposed part  32  are aligned in the z direction. The attachment hole of the energization bus bar  307  in the part adjacent to the high side switch  311  and the bolt hole  30   c  of the second exposed part  33  are aligned in the z direction. In this status, a bolt shaft is inserted through the bolt hole  30   c  and the attachment hole. Then a nut is fastened from the end of the bolt shaft toward a bolt head. The energization bus bar  307  and the electrical-conduction bus bar  30  are held between the bolt head and the nut. With this configuration, the energization bus bar  307  and the electrical-conduction bus bar  30  are brought into contact, and the energization bus bar  307  and the electrical-conduction bus bar  30  are electrically and mechanically connected to each other. As described above, in the energization bus bar  307 , the divided part adjacent to the reactor  313  and the divided part adjacent to the high side switch  311  are bridged with the electrical-conduction bus bar  30 . A common current flows through the energization bus bar  307  and the electrical-conduction bus bar  30 . 
     As shown in (a) of  FIG.  8   , the covered part  31  has a narrow part  31   a  at which the dimension in the x direction is locally short. In the narrow part  31   a  of the present embodiment, the dimension in the x direction is reduced in stepwise. In the narrow part  31   a , the dimension in the x direction is reduced in two steps, from the first exposed part  32  side of the covered part  31  toward a center point CP of the covered part  31  in they direction. Similarly, in the narrow part  31   a , the dimension in the x direction is reduced in two steps, from the second exposed part  33  side of the covered part  31  toward the center point CP of the covered part  31  in the y direction. Note that the dimension of the narrow part  31   a  in the x direction may be reduced in more steps, or may be continuously reduced. 
     The above-described center point CP is equivalent to the center of gravity of the covered part  31 . The covered part  31  and the narrow part  31   a  are in a line-symmetrical shape with a center line passing through the center point CP in the z direction as a symmetry axis AS. 
     In the narrow part  31   a , the dimension in the x direction is shorter than that of the first exposed part  32  and the second exposed part  33 . The density of a current flowing through the narrow part  31   a  is higher than the density of a current flowing through the first exposed part  32  and the second exposed part  33 . As a result, the intensity of a measured magnetic field to be measured, caused by the current flowing through the narrow part  31   a  is high. 
     As indicated with the magnetoelectric converter  25  in the first sensing unit  21  and the magnetoelectric converter  25  in the second sensing unit  22 , schematically surrounded with broken lines respectively, in (a) and (b) of  FIG.  8   , the first sensing unit  21  and the second sensing unit  22  are each arranged to be opposed to and to be spaced from the narrow part  31   a  in the z direction. Accordingly, the high-intensity measured magnetic field, caused by the current flowing through the narrow part  31   a , permeates the first sensing unit  21  and the second sensing unit  22  respectively. 
     As described above, the electrical-conduction bus bar  30  extends in the y direction. In the electrical-conduction bus bar  30 , the current flows in the y direction. A measured magnetic field in accordance with Ampere&#39;s law is generated in a circumferential direction about the y direction by the flow of the current in the y direction. The measured magnetic field flows in a ring shape about the electrical-conduction bus bar  30  in a plane defined by the x direction and the z direction. The first sensing unit  21  and the second sensing unit  22  each detect a component of the measured magnetic field along the x direction. 
     As indicated with a broken line in  FIG.  8   , the respective magnetoelectric converters  25  of the first sensing unit  21  and the second sensing unit  22  are aligned in the y direction. The two magnetoelectric converters  25  are symmetrically arranged with respect to the symmetry axis AS. The positions of the two magnetoelectric converters  25  in the x direction and the position of the symmetry axis AS (center point CP) in the x direction are the same. Accordingly, the two magnetoelectric converters  25  are aligned via the center point CP in the y direction. 
     Further, the distances between the two magnetoelectric converters  25  and the covered part  31  in the z direction are the same. As described above, the covered part  31  and the narrow part  31   a  are in a line-symmetrical shape with respect to the symmetry axis AS. As described above, measured magnetic fields having equivalent x-direction components permeate the two magnetoelectric converters  25 . 
     Note that the electrical-conduction bus bar  30  of the present embodiment is produced by press-working a conductive flat plate. In the press working, the flat plate is placed on a die, a puncher is brought to be close to the die to apply a tensile force to the flat plate. With this work, the flat plate is divided into the electrical-conduction bus bar  30  and chips, thus the electrical-conduction bus bar  30  is produced. 
     When the electrical-conduction bus bar  30  is produced by the above-described press working, a shear plane is formed in the electrical-conduction bus bar  30 . A sag occurs in the shear plane on the side of a surface of the electrical-conduction bus bar  30 , which is brought into contact with the puncher first. With this sag, there is a fear of perpendicularity impairment of the shear plane. As a result, the distribution of the measured magnetic field caused by the current flowing through the electrical-conduction bus bar  30  may be deviated from the design. 
     In the present embodiment, the electrical-conduction bus bar  30  is arranged such that, not the surface that is brought into contact with the puncher first, but a surface that is lastly separated with the puncher is adjacent to the wiring board  20 . That is, the surface that is firstly brought into contact with the puncher is the rear surface  30   b , and the surface that is lastly separated from the puncher is the front surface  30   a . The shear plane corresponds to a side surface between the front surface  30   a  and the rear surface  30   b . Accordingly, the perpendicularity impairment on the front surface  30   a  side in the side surface of the electrical-conduction bus bar  30  is suppressed. The front surface  30   a  of the electrical-conduction bus bar  30  opposes the wiring board  20 . With this configuration, the deviation of the distribution of the measured magnetic field which permeates the first sensing unit  21  and the second sensing unit  22  mounted on the wiring board  20  is suppressed. 
     Note that when the electrical-conduction bus bar  30  is produced by press working as described above, it is necessary to determine whether or not a sag has occurred on any of the front surface  30   a  side and the rear surface  30   b  side in the side surface. For the purpose of the above determination, a notch  33   a  as a mark is formed in the second exposed part  33  of the electrical-conduction bus bar  30 . The notch  33   a  of the present embodiment has a semicircular shape. 
     &lt;Shield&gt; 
     As described above, the shield  40  has the first shield  41  and the second shield  42 . As shown in  FIG.  9    and  FIG.  10   , the first shield  41  and the second shield  42  each have a thin plate shape having the thickness in the z direction. In the first shield  41 , one surface  41   a  having a largest area and a rear surface  41   b  on the rear of the one surface  41   a  face in the z direction respectively. In the second shield  42 , one surface  42   a  having a largest area and a rear surface  42   b  on the rear of the widest surface  42   a  face in the z direction respectively. 
     As shown in  FIG.  2    and  FIG.  3   , the first shield  41  and the second shield  42  are provided, in a state where the one surface  41   a  and the one surface  42   a  oppose each other in the z direction, in the sensor housing  50 . The rear surface  41   b  of the first shield  41  and the rear surface  42   b  of the second shield  42  are exposed to the outside of the sensor housing  50  respectively. The rear surface  41   b  and the rear surface  42   b  each form a part of an outer-most surface of the first current sensor  11 . 
     In  FIG.  9   , (a) shows a top view of the first shield; and (b) shows a bottom view of the first shield. In  FIG.  10   , (a) shows a top view of the second shield; and (b) shows a bottom view of the second shield. 
     The first shield  41  and the second shield  42  may be produced by press-joining multiple flat plates made of a soft magnetic material with high magnetic permeability such as permalloy. Otherwise, the first shield  41  and the second shield  42  may be produced by press-extending magnetic steel. 
     The first shield  41  and the second shield  42  of the present embodiment are each produced by press-joining multiple flat plates made of a soft magnetic material. Each of the multiple flat plates is formed with four protrusions which protrude from a main surface toward a rear surface. In correspondence with the protrusions, each of the multiple flat plates is formed with four recesses which are recessed from the rear surface toward the main surface. The multiple flat plates are respectively arranged such that the main surface and the rear surface oppose to each other. Further, the multiple flat plates are laminated such that the protrusions of one of two opposing flat plates are received in the recesses of the other of the two opposing flat plates. In this laminated state, the multiple flat plates are press-joined. With this configuration, the first shield  41  and the second shield  42  are produced. 
     Note that, in the case where the first shield  41  and the second shield  42  are produced by press-extending magnetic steel, the direction in which the magnetic steel is extended with the press-extension is, for example, defined in the x direction. In this case, the atomic arrangement (crystal) of the magnetic steel is aligned in the x direction. As a result, the magnetic permeability in the x direction is higher than the magnetic permeability in the y direction. In this manner, it is possible to provide the magnetic permeability of the shield with anisotropy by specifying the extending direction of the magnetic steel. 
     &lt;First Shield&gt; 
     As shown in  FIG.  9   , the planar shape of the first shield  41  is a rectangular shape with the x direction as a longitudinal direction. Notches  41   c  are formed at four corners of the first shield  41  of the present embodiment. In  FIG.  9   , to clarify the border between the center of the first shield  41  and the opposite ends of the first shield  41  in the y direction, two broken lines extending in the x direction are given to the first shield  41 . In the following description, the center of the first shield  41  in the y direction is indicated as a first center part  41   d . The opposite ends of the first shield  41  in the y direction are indicated as a first opposite end part  41   e . The first center part  41   d  is positioned between the two ends of the first opposite end part  41   e  in the y direction. 
     As clearly indicated with the broken lines, the first opposite end part  41   e  has the length in the x direction shorter than that of the first center part  41   d . In the first opposite end part  41   e , the magnetic permeability in the x direction is thus lower than that in the first center part  41   d . The magnetic field hardly enters the first opposite end part  41   e . Accordingly, the permeation of the magnetic field, via portions (parallel portions) of the first center part  41   d  directly connected to the first opposite end part  41   e  and aligned in the y direction, from one of the two ends of the first opposite end part  41   e  to the other end, is suppressed. The magnetic field hardly permeates the parallel portions of the first center part  41   d . As a result, the parallel portions of the first center part  41   d  are hardly magnetically saturated. 
     The parallel portions of the first center part  41   d , at which the magnetic saturation is suppressed, are aligned with the first sensing unit  21  and the second sensing unit  22  mounted on the wiring board  20  in the z direction. The respective magnetoelectric converters  25  of the first sensing unit  21  and the second sensing unit  22  are positioned between the first center part  41   d  and the narrow part  31   a.    
     &lt;Second Shield&gt; 
     As shown in  FIG.  10   , the planar shape of the second shield  42  is a rectangular shape with the x direction as a longitudinal direction. In  FIG.  10   , to clarify the border between the center of the second shield  42  and the opposite ends of the second shield  42  in the y direction, two broken lines extending in the x direction are given to the second shield  42 . In the following description, the center of the second shield  42  in the y direction is indicated as a second center part  42   d . The opposite ends of the second shield  42  are indicated as a second opposite end part  42   e . The second center part  42   d  is positioned between the two ends of the second opposite end part  42   e  in the y direction. 
     The second shield  42  has two sides  42   f  aligned in the x direction. Each of the two sides  42   f  is formed with an extending part  42   c  extending in the z direction in an area adjacent to the second center part  42   d . The two extending parts  42   c  extend in a direction from the rear surface  42   b  toward the one surface  42   a  in the z direction. The extending part  42   c  has a rectangular parallelepiped shape with the y direction as a longitudinal direction. The extending part  42   c  is formed, upon production of the second shield  42  as described above, after the press-joining of the multiple flat plates made of a soft magnetic material, by bending the joined flat plates. 
     As described above, the first shield  41  and the second shield  42  are provided, in a state where the one surface  41   a  of the first shield  41  and the one surface  42   a  of the second shield  42  are opposed to each other in the z direction, in the sensor housing  50 . In this state where the first shield  41  and the second shield  42  are provided in the sensor housing  50 , the extending part  42   c  extends toward the first shield  41 . An end surface of the extending part  42   c  and the one surface  41   a  of the first center part  41   d  of the first shield  41  are opposed to each other in the z direction. 
     With this configuration, the clearance between the first center part  41   d  of the first shield  41  and the extending part  42   c  of the second shield  42  in the z direction is shorter than the clearance between the one surface  41   a  of the first shield  41  and the one surface  42   a  of the second shield  42  in the z direction. Accordingly, the magnetic field entered the first shield  41  easily permeates the second shield  42  via the extending part  42   c.    
     As described above, the extending part  42   c  extends from the side  42   f  in the area adjacent to the second center part  42   d  in the z direction. The extending part  42   c  is not formed on the side  42   f  in the area adjacent to the second opposite end part  42   e . Therefore, the magnetic field entered the first shield  41  easily permeates the second center part  42   d  of the second shield  42  via the extending part  42   c.    
     The second center part  42   d  is opposed to the first sensing unit  21  and the second sensing unit  22  mounted on the wiring board  20  in the z direction. The magnetoelectric converters  25  and the narrow parts  31   a  of the first sensing unit  21  and the second sensing unit  22  are positioned between the first center part  41   d  and the second center part  42   d.    
     Further, the positions of the magnetoelectric converters  25  in the x direction are between the two extending parts  42   c  of the respective two sides  42   f . When external noise along the x direction attempts to permeate a region between the one surface  41   a  of the first shield  41  and the one surface  42   a  of the second shield  42  in which the magnetoelectric converters  25  are positioned, the external noise attempts to enter not the magnetoelectric converters  25  but the extending parts  42   c . In the extending parts  42   c , the external noise bents its permeation direction so as to permeate through the second shield  42 . As a result, permeation of the external noise through the magnetoelectric converters  25  is suppressed. 
     &lt;Sensor Housing&gt; 
     As shown in  FIG.  3    and  FIG.  11   , the electrical-conduction bus bar  30  and the connection terminal  60  are insert-molded in the sensor housing  50 . The wiring board  20  and the shield  40  are provided in the sensor housing  50 . The electrical-conduction bus bar  30 , the wiring board  20 , and the shield  40  are aligned, away from each other, in the z direction. In  FIG.  11   , (a) shows a top view of the sensor housing; and (b) shows a bottom view of the sensor housing. 
     As shown in  FIG.  5    and  FIG.  11   , the sensor housing  50  has a base  51 , insulating parts  52 , a first surrounding part  53 , a second surrounding part  54 , and a connector part  55 . 
     The base  51  has a rectangular parallelepiped shape with the x direction as a longitudinal direction. The base  51  has six surfaces. The base  51  has a left surface  51   a  and a right surface  51   b  facing in the y direction. The base  51  has an upper surface  51   c  and a lower surface  51   d  facing in the x direction. The base  51  has an upper end surface  51   e  and a lower end surface  51   f  facing in the z direction. 
     As shown in (a) and (c) of  FIG.  5   , the insulating parts  52  are formed in a part of the left surface  51   a  and a part of the right surface  51   b  in the base  51 , respectively. The two insulating parts  52  extend, away from the base  51 , in the y direction. The two insulating parts  52  are aligned via the base  51  in the y direction. The covered part  31  of the electrical-conduction bus bar  30  is covered respectively with the two insulating parts  52  and the base  51 . 
     In a broad way, portions of the covered part  31  adjacent to the first exposed part  32  and the second exposed part  33  are covered with the two insulating parts  52 . The narrow part  31   a  of the covered part  31  is covered with the base  51 . The narrow part  31   a  is positioned between the upper end surface  51   e  and the lower end surface  51   f  of the base  51  in the z direction. An insulating resin material forming the base  51  is positioned between the narrow part  31   a  and the upper end surface  51   e  and between the narrow part  31   a  and the lower end surface  51   f  respectively. 
     As shown in (a) of  FIG.  11   , the first surrounding part  53  is formed on the upper end surface  51   e  of the base  51 . The first surrounding part  53  has a left wall  53   a  and a right wall  53   b  aligned in the y direction. The first surrounding part  53  has an upper wall  53   c  and a lower wall  53   d  aligned in the x direction. 
     These walls forming the first surrounding part  53  are formed along the edge of the upper end surface  51   e . In a circumferential direction about the z direction, the left wall  53   a , the upper wall  53   c , the right wall  53   b , and the lower wall  53   d  are connected in sequence. With this configuration, the first surrounding part  53  has a ring shape opened in the z direction. The first surrounding part  53  surrounds the upper end surface  51   e . The wiring board  20  and the first shield  41  are provided in first storage space provided by the first surrounding part  53  and the upper end surface  51   e.    
     As shown in (b) of  FIG.  11   , the second surrounding part  54  is formed on the lower end surface  51   f  of the base  51 . The second surrounding part  54  has a left wall  54   a  and a right wall  54   b  aligned in the y direction. The second surrounding part  54  has an upper wall  54   c  and a lower wall  54   d  aligned in the x direction. 
     These walls forming the second surrounding part  54  are formed around the above-described part of the base  51  aligned with the narrow part  31   a  in the z direction on the lower end surface  51   f . In the circumferential direction about the z direction, the left wall  54   a , the upper wall  54   c , the right wall  54   b , and the lower wall  54   d  are connected in sequence. With this configuration, the second surrounding part  54  has a ring shape opened in the z direction. The second surrounding part  54  surrounds a part of the lower end surface  51   f . The second shield  42  is provided in second storage space provided by the second surrounding part  54  and the lower end surface  51   f.    
     In the second storage space, the size of a plane orthogonal to the z direction is smaller than that of the first storage space. The second storage space is aligned with a part of the first storage space in the z direction. A part of the first storage space, which is not aligned with the second storage space in the z direction, is aligned with the connector part  55  in the z direction. 
     As shown in (b) of  FIG.  5    and (b) of  FIG.  11   , the connector part  55  is formed on the lower end surface  51   f  of the base  51 . The connector part  55  extends, away from a part of the lower end surface  51   f  not surrounded with the second surrounding part  54  (non-surrounded part), in the z direction. The connector part  55  forms a part of the lower wall  54   d.    
     The connector part  55  has a pillar part  55   a  extending from the lower end surface  51   f  in the z direction, and a surrounding part  55   c  surrounding an apical surface  55   b  of the pillar part  55   a  in the circumferential direction about the z direction. The connection terminal  60  extends in the z direction. The connection terminal  60  is covered respectively with the pillar part  55   a  and a part of the base  51  aligned with the pillar part  55   a  in the z direction. 
     One end of the connection terminal  60  is exposed from the apical surface  55   b  to the outside of the pillar part  55   a . The periphery of the one end of the connection terminal  60  exposed from the apical surface  55   b  is surrounded by the above-described surrounding part  55   c . With this configuration, the surrounding part  55   c  and the one end of the connection terminal  60  form a connector. A connector of a wire harness or the like is connected to the connector. 
     The other end of the connection terminal  60  is exposed from the upper end surface  51   e  to the outside of the base  51 . The other end of the connection terminal  60  is provided in the above-described first storage space. The connection terminal  60  is away from the part of the electrical-conduction bus bar  30  covered with the base  51  (narrow part  31   a ) in the x direction. The other end of the connection terminal  60  is positioned adjacent to the lower wall  53   d  in the x direction. The narrow part  31   a  is positioned adjacent to the upper wall  53   c . The insulating resin material forming the base  51  is positioned between the part of the connection terminal  60  and the part of the narrow part  31   a  respectively insert-molded in the sensor housing  50 . 
     As described above, the direct current inputted to or outputted from the battery  200  flows through the electrical-conduction bus bar  30 . In the connection terminal  60 , an electric signal with a smaller current amount than the direct current flows between the wiring board  20  and the battery ECU  801 . When the creepage distance between the electrical-conduction bus bar  30  and the connection terminal  60  is short, there is a fear of short-circuit due to conduction between the electrical-conduction bus bar  30  and the connection terminal  60 . 
     A rib  52   a  for suppressing such inconvenience is formed in the insulating part  52 . The rib  52   a  protrudes from the insulating part  52  in the z direction. The rib  52   a  extends in the x direction. The length of the rib  52   a  in the x direction is longer than the respective lengths of the first exposed part  32  and the second exposed part  33  in the x direction. 
     The rib  52   a  is positioned between each of the first exposed part  32  and the second exposed part  33  of the electrical-conduction bus bar  30 , which are positioned outside of the insulating part  52 , and the other end of the connection terminal  60 , which is exposed from the upper end surface  51   e  to the outside. With the ribs  52   a , the creepage distance between the electrical-conduction bus bar  30  and the connection terminal  60  on the surface of the sensor housing  50  is elongated. With this configuration, the short circuit between the electrical-conduction bus bar  30  and the connection terminal  60  is suppressed. 
     Further, the ribs  52   a  are positioned, respectively, between the first exposed part  32  and the second exposed part  33 , and the first shield  41  and the second shield  42 . With this configuration, short circuit between the electrical-conduction bus bar  30  and the shield  40  is also suppressed. 
     It is possible to reduce the length of the insulating part  52  in the y direction by the extension of the creepage distance with the ribs  52   a . The length of the insulating part  52  in the y direction is reduced by about 85%. With this configuration, an increase of the physical constitution of the first current sensor  11  is suppressed. 
     &lt;Wiring Board Fixing Form to Sensor Housing&gt; 
     As shown in (a) of  FIG.  11    and (a) of  FIG.  12   , a board support pin  56   a  and a board adhesion pin  56   b  locally extending in the z direction are formed on the upper end surface  51   e  of the base  51 . Multiple board support pins  56   a  and board adhesion pins  56   b  are formed on the upper end surface  51   e . In  FIG.  12   , (a) shows a perspective view of the sensor housing; and (b) shows a perspective view of the sensor housing in which the wiring board is provided. In  FIG.  12   , for explanation of these pins, a part of reference numerals is omitted. 
     The multiple board support pins  56   a  each have an apical surface  56   c  facing in the z direction. The positions of the multiple apical surfaces  56   c  in the z direction are equal to each other. Similarly, the multiple board adhesion pins  56   b  each have an apical surface  56   d  facing in the z direction. The positions of the multiple apical surfaces  56   d  in the z direction are equal to each other. 
     As shown in  FIG.  13   , the length between the apical surface  56   c  of the board support pin  56   a  and the upper end surface  51   e  in the z direction is defined as L 1 . The length between the apical surface  56   d  of the board adhesion pin  56   b  and the upper end surface  51   e  in the z direction is defined as L 2 . As clearly indicated in the figure, the length L 1  is longer than the length L 2 . 
     Therefore, the apical surface  56   c  of the board support pin  56   a  is away from the upper end surface  51   e , further than the apical surface  56   d  of the board adhesion pin  56   b , in the z direction. The wiring board  20  is mounted, in a state where the opposing surface  20   a  is in contact with the apical surfaces  56   c  of the board support pins  56   a , in the sensor housing  50 . The board support pin  56   a  corresponds to a board support part. The apical surface  56   c  corresponds to a support surface. 
     In the state where the wiring board  20  is mounted on the apical surfaces  56   c  of the board support pins  56   a , the opposing surface  20   a  of the wiring board  20  is spaced from the apical surfaces  56   d  of the board adhesion pins  56   b  in z direction. A board adhesive  56   e  for adhesion fixing of the wiring board  20  and the board adhesion pin  56   b  is provided between the wiring board  20  and the board adhesion pin  56   b . The board adhesion pin  56   b  corresponds to a board bonding member. The apical surface  56   d  corresponds to a mounting surface. 
     Upon adhesion fixing of the wiring board  20  and the sensor housing  50  with the board adhesive  56   e , the temperature of the board adhesive  56   e  is set to be higher than the temperature of an environment where the first current sensor  11  is provided. In this case, the temperature of the board adhesive  56   e  may be set to about 150° C., for example. At this temperature, the board adhesive  56   e  has fluidity. As the board adhesive  56   e , a silicone adhesive may be employed. 
     The board adhesive  56   e  having fluidity at about 150° C. is applied to the apical surfaces  56   d  of the board adhesion pins  56   b . Then, the wiring board  20  is placed in the sensor housing  50  so that the apical surfaces  56   c  of the board support pins  56   a  and the board adhesive  56   e  are brought into contact with the opposing surface  20   a  of the wiring board  20 . Thereafter, the board adhesive  56   e  is cooled down to a room temperature to be solidified. 
     At the temperature of the environment where the first current sensor  11  is provided, a residual stress condensing to its own center occurs to the board adhesive  56   e . The wiring board  20  and the board adhesion pin  56   b  are brought closer to each other with the residual stress. The contact state between the opposing surface  20   a  of the wiring board  20  and the apical surfaces  56   c  of the board support pins  56   a  is maintained. 
     As a result, misalignment of the wiring board  20  with respect to the sensor housing  50  does not depend on shape variation of the board adhesive  56   e  having fluidity upon adhesion fixing any longer. The misalignment of the wiring board  20  with respect to the sensor housing  50  is caused by a manufacturing error of the sensor housing  50 . In other words, the misalignment of the wiring board  20  with respect to the electrical-conduction bus bar  30  insert-molded in the sensor housing  50  depends on the manufacturing error of the sensor housing  50 . 
     In the present embodiment, three board support pins  56   a  are formed on the upper end surface  51   e . Two of the three board support pins  56   a  are aligned, away from each other, in the y direction. The remaining one board support pin  56   a  is away from a middle point between the two board support pins  56   a  aligned in the y direction, in the x direction. The apical surfaces  56   c  of the three board support pins  56   a  form apexes of an isosceles triangle. The narrow part  31   a  of the electrical-conduction bus bar  30  is positioned between the two board support pins  56   a  aligned in the y direction and the remaining one board support pin  56   a.    
     In the present embodiment, three board adhesion pins  56   b  are formed on the upper end surface  51   e . Two of the three board adhesion pins  56   b  are aligned, away from each other, in the y direction. The remaining one board adhesion pin  56   b  is away from a middle point between the two board support pins  56   a  aligned in the y direction, in the x direction. The apical surfaces  56   d  of the three board adhesion pins  56   b  form apexes of an isosceles triangle. 
     The other ends of the multiple connection terminals  60  are aligned between the two board support pins  56   a  aligned in the y direction. The remaining one board support pin  56   a  is positioned in the middle point between the two board adhesion pins  56   b  aligned in the y direction. Accordingly, the remaining one board support pin  56   a  is aligned with the remaining one board adhesion pin  56   b  in the x direction. The center point CP of the narrow part  31   a  is positioned between the remaining one board support pin  56   a  and the remaining one board adhesion pin  56   b  in the x direction. 
     With the above-described configuration, the isosceles triangle formed by connecting the apical surfaces  56   c  of the three board support pins  56   a  and the isosceles triangle formed by connecting the apical surfaces  56   d  of the three board adhesion pins  56   b  overlap each other in the z direction. The center point CP of the narrow part  31   a  is positioned in the region provided by these two isosceles triangles overlapping in the z direction. 
     The wiring board  20  is provided in the sensor housing  50  to be opposed to the two isosceles triangles, respectively, in the z direction. In the wiring board  20 , the connection between a part opposing to the two isosceles triangles and the sensor housing  50  is more stable, because of the contact with the board support pins  56   a  and the connection with the board adhesion pins  56   b  via the board adhesive  56   e , than the connection between a part without opposing to the two isosceles triangles and the sensor housing  50 . The first sensing unit  21  and the second sensing unit  22  are mounted on the part of the wiring board  20  with stable connection with the sensor housing  50 . 
     In a state where the wiring board  20  is mounted on the board support pins  56   a  and fixed via the board adhesive  56   e  to the board adhesion pins  56   b , the opposing surface  20   a  of the wiring board  20  and the upper end surface  51   e  of the base  51  are opposed to each other and spaced from each other in the z direction. If there is no manufacturing error or the like, the clearance between the opposing surface  20   a  and the upper end surface  51   e  is constant over the entire surface, and the opposing surface  20   a  and the upper end surface  51   e  are in parallel relationship. 
     As described above, the narrow part  31   a  of the electrical-conduction bus bar  30  is insert-molded in the base  51 . If there is no manufacturing error or the like, the clearance between the surface  30   a  of the narrow part  31   a  and the upper end surface  51   e  of the base  51  is constant over the entire surface, and the surface  30   a  of the narrow part  31   a  and the upper end surface  51   e  of the base  51  are in parallel relationship. 
     Because of the parallel relationship described as above, if there is no manufacturing error or the like, the clearance between the opposing surface  20   a  of the wiring board  20  and the surface  30   a  of the narrow part  31   a  is also constant over the entire surface, and the opposing surface  20   a  of the wiring board  20  and the surface  30   a  of the narrow part  31   a  are in parallel relationship. 
     As described above, the wiring board  20  is formed by laminating multiple resin layers and metal layers in the z direction. Therefore, the manufacturing error of the thickness of the wiring board  20  in the z direction is likely to be large. The manufacturing error of the thickness of the wiring board  20  in the z direction is about twice of the manufacturing error due to the position of the electrical-conduction bus bar  30  insert-molded in the sensor housing  50  in the z direction and the arrangement error of the wiring board  20  in the z direction with respect to the sensor housing  50 . 
     In the wiring board  20 , the first sensing unit  21  and the second sensing unit  22  are provided on the opposing surface  20   a , which opposes to the electrical-conduction bus bar  30 . Therefore, the distance between the first sensing unit  21  and the electrical-conduction bus bar  30  and the distance between the second sensing unit  22  and the electrical-conduction bus bar  30  in the z direction do not depend on the thickness of the wiring board  20  in the z direction. Thus, variations of the distance between the first sensing unit  21  and the electrical-conduction bus bar  30  and the distance between the second sensing unit  22  and the electrical-conduction bus bar  30  in the z direction due to the manufacturing error of the thickness of the wiring board  20  in the z direction are suppressed. 
     Note that the number of the board support pins  56   a  and the number of the board adhesion pins  56   b  are not limited to three. The number of the board support pins  56   a  may be four or more. The number of the board adhesion pins  56   b  may be one, two, four or more. 
     When three or more board support pins  56   a  and three or more board adhesion pins  56   b  are provided, it is desirable to configure such that the polygon formed by connecting the apical surfaces  56   c  of the three or more board support pins  56   a  and the polygon formed by connecting the apical surfaces  56   d  of the three or more board adhesion pins  56   b  overlap each other in the z direction. In this configuration, the first sensing unit  21  and the second sensing unit  22  may be mounted in a region of the wiring board  20  opposing to the two polygons in the z direction. With this configuration, the misalignment of the first sensing unit  21  and the misalignment of the second sensing unit  22  respectively with respect to the sensor housing  50  are suppressed. 
     As the names of board support pin  56   a  and board adhesion pin  56   b  indicate, the example where these pins have pillar shapes extending in the z direction has been shown. However, the shapes of these pins are not limited to the pillar shapes. As long as the apical surface  56   c  of the board support pin  56   a  is away from the upper end surface  51   e  further than the apical surface  56   d  of the board adhesion pin  56   b , the shape is not particularly limited. 
     &lt;Fixing Form of First Shield to Sensor Housing&gt; 
     As shown in (a) of  FIG.  11    and (a) of  FIG.  14   , a shield support pin  57   a  and a shield adhesion pin  57   b  are formed on the upper end surface  51   e  of the base  51  to locally extending in the z direction. Multiple shield support pins  57   a  and shield adhesion pins  57   b  are formed on the upper end surface  51   e . In  FIG.  14   , (a) shows a perspective view of the sensor housing provided with the wiring board; and (b) shows a perspective view of the sensor housing provided with the wiring board and the shield. In  FIG.  14   , a part of reference numerals is omitted for explanation of these pins. 
     The multiple shield support pins  57   a  each have an apical surface  57   c  facing in the z direction. The positions of the multiple apical surfaces  57   c  in the z direction are equal to each other. Similarly, the multiple shield adhesion pins  57   b  each have an apical surface  57   d  facing in the z direction. The positions of the apical surfaces  57   d  in the z direction are equal to each other. 
     As shown in  FIG.  15   , in the respective shield support pin  57   a  and shield adhesion pin  57   b , the length in the z direction is longer than that of the board support pin  56   a . More specifically, in the respective shield support pin  57   a  and shield adhesion pin  57   b , the length in the z direction is longer than that of the board support pin  56   a  by an amount equal to or larger than the thickness of the wiring board  20 . As described above, in the state where the wiring board  20  is mounted in the sensor housing  50 , the apical surface  57   c  of the shield support pin  57   a  and the apical surface  57   d  of the shield adhesion pin  57   b  are respectively further from the upper end surface  51   e  than the rear surface  20   b  of the wiring board  20  in the z direction. Note that a configuration where the difference between the length of the shield adhesion pin  57   b  and the length of the board support pin  56   a  in the z direction is shorter than the thickness of the wiring board  20  in the z direction may be employed. 
     As shown in  FIG.  15   , the length between the apical surface  57   c  of the shield support pin  57   a  and the upper end surface  51   e  in the z direction is L 3 . The length between the apical surface  57   d  of the shield adhesion pin  57   b  and the upper end surface  51   e  in the z direction is L 4 . As clearly indicated in the figure, the length L 3  is longer than the length L 4 . 
     The apical surface  57   c  of the shield support pin  57   a  is away from the upper end surface  51   e  further than the apical surface  57   d  of the shield adhesion pin  57   b  in the z direction. The first shield  41  is mounted in the sensor housing  50  in the state where the one surface  41   a  is in contact with the apical surface  57   c  of the shield support pin  57   a . The shield support pin  57   a  corresponds to a shield support part. The apical surface  57   c  corresponds to the contact surface. 
     In the state where the one surface  41   a  of the first shield  41  is mounted on the apical surface  57   c  of the shield support pin  57   a , the one surface  41   a  of the first shield  41  and the apical surface  57   d  of the shield adhesion pin  57   b  are away from each other in the z direction. The board adhesive  56   e  for adhesion fixing is provided between the first shield  41  and the shield adhesion pin  57   b . The shield adhesion pin  57   b  corresponds to a shield adhesion part. The apical surface  57   d  corresponds to the application surface. 
     Upon the adhesion fixing between the first shield  41  and the sensor housing  50  with the shield adhesive  57   e , the temperature of the shield adhesive  57   e  is set to be higher than the temperature of the environment where the first current sensor  11  is provided. The temperature of the shield adhesive  57   e  in this case may be set to about 150° C., for example. At this temperature, the shield adhesive  57   e  has fluidity. As the shield adhesive  57   e , a silicone adhesive may be employed. 
     The shield adhesive  57   e  having fluidity at about 150° C. is applied to the apical surface  57   d  of the shield adhesion pin  57   b . Then, the first shield  41  is placed in the sensor housing  50  so as to bring the apical surface  57   c  of the shield support pin  57   a  and the shield adhesive  57   e  respectively into contact with the one surface  41   a  of the first shield  41 . Thereafter, the shield adhesive  57   e  is cooled down to the room temperature to be solidified. 
     Thus, in the shield adhesive  57   e , a residual stress condensing to its own center occurs at the temperature of the environment where the first current sensor  11  is provided. The first shield  41  and the shield adhesion pin  57   b  are brought closer to each other with the residual stress. The contact state between the one surface  41   a  of the first shield  41  and the apical surface  57   c  of the shield support pin  57   a  is maintained. 
     As a result, the misalignment of the first shield  41  with respect to the sensor housing  50  does not depend on the shape variation of the shield adhesive  57   e  having fluidity upon adhesion fixing any longer. The misalignment of the first shield  41  with respect to the sensor housing  50  is caused by the manufacturing error of the sensor housing  50 . In other words, the misalignment of the first shield  41  with respect to the wiring board  20  fixed to the sensor housing  50  depends on the manufacturing error of the sensor housing  50 . 
     In the present embodiment, three shield support pins  57   a  are formed on the upper end surfaces  51   e . One of the three shield support pins  57   a  is connected integrally with the left wall  53   a . One of the remaining two shield support pins  57   a  is connected integrally with the right wall  53   b . The remaining one shield support pin  57   a  is connected integrally with the upper wall  53   c . The apical surfaces  57   c  of the three shield support pins  57   a  form apexes of a triangle. 
     The shield support pin  57   a  connected integrally with the left wall  53   a  and the shield support pin  57   a  connected integrally with the right wall  53   b  are aligned in the y direction. The interval between the two shield support pins  57   a  and the shield support pin  57   a  connected integrally with the upper wall  53   c  are away from each other in the x direction. The first sensing unit  21  and the second sensing unit  22  of the wiring board  20  are positioned in the triangular region formed by connecting the apical surfaces  57   c  of the three shield support pins  57   a.    
     In the present embodiment, three shield adhesion pins  57   b  are formed on the upper end surface  51   e . One of the three shield adhesion pins  57   b  is connected integrally with the left wall  53   a . One of the remaining two shield adhesion pins  57   b  is connected integrally with the right wall  53   b . The remaining one shield adhesion pin  57   b  is connected integrally with the upper wall  53   c . The apical surfaces  57   d  of the three shield adhesion pins  57   b  form apexes of a triangle. 
     The shield adhesion pin  57   b  connected integrally with the left wall  53   a , and the shield adhesion pin  57   b  connected integrally with the right wall  53   b , are aligned in the y direction. The interval between the two shield adhesion pins  57   b  and the shield adhesion pin  57   b  connected integrally with the upper wall  53   c  are away from each other in the x direction. The triangular region formed by connecting the apical surfaces  57   d  of the three shield adhesion pins  57   b  is aligned with the first sensing unit  21  and the second sensing unit  22  in the z direction. 
     Further, one shield support pin  57   a  and one shield adhesion pin  57   b  are aligned with each other on each of the left wall  53   a  and the right wall  53   b . One shield support pin  57   a  and one shield adhesion pin  57   b  are aligned with each other on the upper wall  53   c . The triangle formed by connecting the apical surfaces  57   c  of the three shield support pins  57   a  and the triangle formed by connecting the apical surfaces  57   d  of the three shield adhesion pins  57   b  overlap each other in the z direction. The overlapping region of the triangles in the z direction and the center point CP of the narrow part  31   a  are aligned in the z direction. 
     The first shield  41  is provided in the sensor housing  50  so as to oppose the two triangles in the z direction. In the first shield  41 , the connection with the sensor housing  50  of the part opposing to the two triangles is more stable, by the contact with the shield support pin  57   a  and the connection with the shield adhesion pin  57   b  via the shield adhesive  57   e , than that of the part without opposing to the two triangles. 
     The part of the first shield  41  with stable connection to the sensor housing  50  is aligned with both of the first sensing unit  21  and the second sensing unit  22  of the wiring board  20  in the z direction. Specifically, the first center part  41   d  of the first shield  41  is aligned with each of the first sensing unit  21  and the second sensing unit  22  in the z direction. 
     In the state where the first shield  41  is mounted on the shield support pin  57   a  and fixed via the shield adhesive  57   e  to the shield adhesion pin  57   b , the one surface  41   a  of the first shield  41  and the rear surface  20   b  of the wiring board  20  are opposed to and away from each other in the z direction. If there is no manufacturing error or the like, the distance between the one surface  41   a  and the rear surface  20   b  is constant over the entire surface, and the one surface  41   a  and the rear surface  20   b  are in parallel relationship. Accordingly, the distance between the opposing surface  20   a  of the wiring board  20  and the one surface  41   a  of the first shield  41  is also constant over the entire surface, and the opposing surface  20   a  of the wiring board  20  and the one surface  41   a  of the first shield  41  are in parallel relationship. 
     Note that, as shown in  FIG.  6    and (a) in  FIG.  14   , notches  20   g  to allow the above-described shield support pins  57   a  and shield adhesion pins  57   b  respectively to pass through to positions above the wiring board  20  are formed at ends the wiring board  20 . Multiple through holes  20   h  to allow the other ends of the connection terminals  60  to pass through are formed in the wiring board  20 . 
     As shown in  FIG.  6   , the multiple through holes  20   h  are aligned in the y direction. In the wiring board  20 , the part in which the multiple through holes  20   h  are formed is aligned with the part on which the first sensing unit  21  and the second sensing unit  22  are mounted in the x direction. In the wiring board  20 , a first notch  20   i  to guide the position of the wiring board  20  with respect to the sensor housing  50  in the x direction when the wiring board  20  is mounted in the sensor housing  50  is formed between the two parts aligned in the x direction. Further, in the wiring board  20 , a second notch  20   j  to guide the position of the wiring board  20  with respect to the sensor housing  50  in the y direction when the wiring board  20  is mounted in the sensor housing  50  is formed in the part where the first sensing unit  21  and the second sensing unit  22  are mounted. 
     In correspondence with the above configuration, as shown in (a) of  FIG.  11    and (b) of  FIG.  12   , a first projection  53   e  to be received in the first notch  20   i  is formed on each of the left wall  53   a  and the right wall  53   b  of the sensor housing  50 . A second projection  53   f , which is to be opposed to the second notch  20   j  in the y direction, is formed on each of the left wall  53   a  and the right wall  53   b . The first notch  20   i  and the first projection  53   e  have similar shapes and extend in the y direction. The second notch  20   j  and the second projection  53   f  have similar shapes and extend in the x direction. 
     The number of the above-described shield support pins  57   a  and the number of the shield adhesion pins  57   b  are not limited to the above-described example. The number of the shield support pins  57   a  may be four or more. The number of the shield adhesion pins  57   b  may be one, two, four or more. 
     When three or more shield support pins  57   a  and three or more shield adhesion pins  57   b  are employed, it is desirable to configure such that the polygon formed by connecting the apical surfaces  57   c  of the three or more shield support pins  57   a  and the polygon formed by connecting the apical surfaces  57   d  of the three or more shield adhesion pins  57   b  overlap each other in the z direction. In this configuration, the part of the first shield  41  opposing to the two polygons in the z direction may be aligned with both of the first sensing unit  21  and the second sensing unit  22  of the wiring board  20  in the z direction. In such a case, the misalignment of the first shield  41  with respect to the first sensing unit  21  and the misalignment of the first shield  41  with respect to the second sensing unit  22  are suppressed. 
     As the names of shield support pin  57   a  and shield adhesion pin  57   b  indicate, the example where these pins have pillar shapes extending in the z direction has been shown. However, the shapes of the pins are not limited to the pillar shapes. As long as the apical surface  57   c  of the shield support pin  57   a  is away from the upper end surface  51   e  further than the apical surface  57   d  of the shield adhesion pin  57   b , the shape is not particularly limited. 
     &lt;Fixing Form of Second Shield to Sensor Housing&gt; 
     As shown in (b) of  FIG.  11    and  FIG.  15   , multiple shield support pins  57   a  are formed also on the lower end surface  51   f  of the base  51 . 
     Differently from the first shield  41 , the wiring board  20  is not provided between the sensor housing  50  and the second shield  42 . Therefore, in the shield support pin  57   a  formed on the lower end surface  51   f , the length in the z direction is shorter than that of the shield support pin  57   a  formed on the upper end surface  51   e . The positions of the respective ends of the multiple board support pins  56   a  in the z direction are equal to each other. The second shield  42  is mounted in the sensor housing  50  in the state where the one surface  42   a  is in contact with the apical surface  57   c  of the shield support pin  57   a.    
     The one surface  42   a  of the second shield  42 , mounted on the apical surface  57   c  of the shield support pin  57   a , is away from the lower end surface  51   f  in the z direction. The shield adhesive  57   e  is provided between the second shield  42  and the lower end surface  51   f.    
     Upon adhesion fixing between the second shield  42  and the sensor housing  50  with the shield adhesive  57   e , the temperature of the shield adhesive  57   e  is also set to be higher than the temperature of the environment where the first current sensor  11  is provided. 
     The shield adhesive  57   e  having fluidity is applied to the lower end surface  51   f . Then, the second shield  42  is placed in the sensor housing  50  so as to bring the apical surface  57   c  of the shield support pin  57   a  and the shield adhesive  57   e  respectively into contact with the one surface  42   a  of the second shield  42 . Thereafter, the shield adhesive  57   e  is cooled down to the room temperature to be solidified. 
     With this configuration, also in the shield adhesive  57   e  provided on the lower end surface  51   f , a residual stress condensing to its own center occurs at the temperature of the environment where the first current sensor  11  is provided. The second shield  42  and the shield adhesion pin  57   b  are brought closer to each other with the residual stress. The contact status between the one surface  42   a  of the second shield  42  and the apical surface  57   c  of the shield support pin  57   a  is maintained. 
     As a result, the misalignment of the second shield  42  with respect to the sensor housing  50  does not depend on the shape variation of the shield adhesive  57   e  having fluidity upon the adhesion fixing any longer. The misalignment of the second shield  42  with respect to the sensor housing  50  is caused by the manufacturing error of the sensor housing  50 . In other words, the misalignment of the second shield  42  with respect to the wiring board  20  fixed to the sensor housing  50  depends on the manufacturing error of the sensor housing  50 . 
     In the present embodiment, four shield support pins  57   a  are formed on the lower end surface  51   f . The apical surfaces  57   c  of the four shield support pins  57   a  form vertices of a rectangle. The rectangle formed by connecting the apical surfaces  57   c  of the four shield support pins  57   a  is aligned with the center point CP of the narrow part  31   a  in the z direction. The shield adhesive  57   e  is applied to a region opposing to the rectangle in the lower end surface  51   f.    
     The second shield  42  is provided in the sensor housing  50  to be opposed to the above-described rectangle in the z direction. In the part of the second shield  42  opposing to the rectangle, the connection to the sensor housing  50  is more stable by the contact with the shield support pin  57   a  and the connection via the shield adhesive  57   e  to the lower end surface  51   f , than the connection of the part without opposing to the rectangle to the sensor housing  50 . 
     The part of the second shield  42 , with stable connection to the sensor housing  50 , is aligned with both of the first sensing unit  21  and the second sensing unit  22  of the wiring board  20  in the z direction. Specifically, the second center part  42   d  of the second shield  42  is aligned respectively with the first sensing unit  21  and the second sensing unit  22  in the z direction. 
     Note that the number of shield support pins  57   a  formed on the lower end surface  51   f  is not limited to four. As long as the number of shield support pins  57   a  is equal to or larger than three, any number of shield support pins  57   a  may be employed. 
     When three or more shield support pins  57   a  are provided, it may be configured such that a region of the second shield  42 , opposing to the polygon formed by connecting the apical surfaces  57   c  of the three or more shield support pins  57   a  in the z direction, is aligned respectively with the first sensing unit  21  and the second sensing unit  22  in the z direction. With this configuration, the misalignment of the second shield  42  with respect to the first sensing unit  21  and the misalignment of the second shield  42  with respect to the second sensing unit  22  are suppressed. 
     As described above, the extending parts  42   c  extending in the z direction are formed on the two sides  42   f  of the second shield  42  aligned in the x direction. Two grooves  51   g  for arranging the extending parts  42   c  are formed in the lower end surface  51   f.    
     As shown in (b) of  FIG.  11    and in  FIG.  13   , the two grooves  51   g  are aligned in the x direction between the upper wall  54   c  and the lower wall  54   d . The two grooves  51   g  are each formed from the lower end surface  51   f  toward the upper end surface  51   e  in the z direction. A part of one of the two grooves  51   g  is formed by the upper wall  54   c . A part of the remaining one groove  51   g  is formed by the lower wall  54   d . The covered part  31  is positioned between the two grooves  51   g . Accordingly, the covered part  31  is positioned between the two extending parts  42   c  of the second shield  42 . 
     &lt;Lengths of Support Pin and Adhesion Pin&gt; 
     The upper end surface  51   e  of the base  51  is divided into an exposed part from which the other end of the connection terminal  60  expose and a part which covers the narrow part  31   a , which are aligned in the x direction but with the above-described first projections  53   e  in the y direction as a boundary. In the upper end surface  51   e , the exposed part from which the other end of the connection terminal  60  expose is positioned adjacent to the lower end surface  51   f  than the part which covers the narrow part  31   a  in the z direction. Accordingly, the distance between the exposed part of the upper end surface  51   e  from which the other end of the connection terminal  60  expose and the opposing surface  20   a  of the wiring board  20  in the z direction is longer than the distance between the part of the upper end surface  51   e  which covers the narrow part  31   a  and the opposing surface  20   a  of the wiring board  20  in the z direction. The distance between the exposed part of the upper end surface  51   e  from which the other end of the connection terminal  60  expose and the opposing surface  20   a  of the wiring board  20  is provided so as to ensure a distance for insertion of the other end of the connection terminal  60  into the through hole  20   h  of the wiring board  20 . 
     In this manner, in the upper end surface  51   e , the position of the exposed part from which the other end of the connection terminal  60  expose and the position of the part which covers the narrow part  31   a  are different in the z direction. The board support pins  56   a  are formed respectively in these two parts. In the present embodiment, although the parts of the upper end surface  51   e  are at different positions in the z direction, the apical surfaces  56   c  of the multiple board support pins  56   a  are at the same positions in the z direction. Thus, the lengths of the multiple board support pins  56   a  in the z direction are different. 
     The lengths of the multiple board support pins  56   a  in the z direction are not uniformly equal to the length L 1  shown in  FIG.  13   . The length L 1  indicates the length of the board support pin  56   a  formed on the part of the upper end surface  51   e  which covers the narrow part  31   a  in the z direction. The length of the board support pin  56   a  formed in the exposed part of the upper end surface  51   e  from which the other end of the connection terminal  60  expose in the z direction is longer than the length L 1  by the difference in position of the divided two parts of the upper end surface  51   e  in the z direction. 
     As described above, the length of the support pin in the z direction may differ in correspondence with the position of the surface where the pin is formed in the z direction as long as the positions of the respective apical surfaces  56   c  of the multiple board support pins  56   a  in the z direction are the same. The configuration is true for the multiple shield support pins  57   a.    
     Note that, when the wiring board  20  is mounted in the sensor housing  50 , the board adhesive  56   e  having fluidity is applied to the apical surfaces  56   d  of the board adhesion pins  56   b . The shape of the board adhesive  56   e , having fluidity, is variable in the z direction. Accordingly, the positions of the apical surfaces  56   d  of the multiple board adhesion pins  56   b  may be different. This is also true for the multiple shield adhesion pins  57   b.    
     &lt;Second Current Sensor and Third Current Sensor&gt; 
     Next, the second current sensor  12  will be described in detail. Note that the configuration of the second current sensor  12  and the configuration of the third current sensor  13  are substantially the same. Accordingly, explanation of the third current sensor  13  will be omitted. 
     Further, the second current sensor  12  has constituent elements common to the first current sensor  11 . In the following description, explanation of the points same as those of the first current sensor  11  will be omitted, and the differences will be mainly described. 
     As described above, the second current sensor  12  is provided on the first energization bus bar  341  and the second energization bus bar  342 . To detect the current flowing in the first energization bus bar  341  and the current flowing in the second energization bus bar  342  respectively, the second current sensor  12  has two individual sensors  71  having a function equivalent to the function of the first current sensor  11 . Further, the second current sensor  12  has a wiring case  72  accommodating the two individual sensors  71 . 
     One of the two individual sensors  71  detects the magnetic field generated from the alternating current which flows through the first energization bus bar  341 . The other one of the two individual sensors  71  detects the magnetic field generated from the alternating current which flows through the second energization bus bar  342 . 
       FIG.  16    shows the two individual sensors  71 . The two individual sensors  71  have the same shape. The structural differences between the individual sensor  71  and the first current sensor  11  include the connecting part in the electrical-conduction bus bar  30  with respect to the energization bus bar, the shape of the connector part  55  which covers the connection terminal  60 , and the like. That is, the structural differences between the individual sensor  71  and the first current sensor  11  include the shape of the first exposed part  32  and the second exposed part  33  of the electrical-conduction bus bar  30 , and elimination of the surrounding part  55   c , and the like. 
     The individual sensor  71  and the first current sensor  11  have the structural differences because the objects to which the individual sensor  71  and the first current sensor  11  are connected are difference. The first current sensor  11  is connected to the energization bus bar  307  of the converter  310 . The second current sensor  12  is connected to the first energization bus bar  341  and the second energization bus bar  342  of the first inverter  320 . Note that the internal structure of the individual sensor  71  and the internal structure of the first current sensor  11  are the same. Accordingly, the individual sensor  71  achieves similar effects to those of the first current sensor  11 . 
     The multiple individual sensors  71  are accommodated in the wiring case  72  shown in  FIG.  17   . As shown in  FIG.  18   , the multiple individual sensors  71  can be accommodated collectively in the wiring case  72 . As shown in  FIG.  19   , the second current sensor  12  is configured by accommodating the multiple individual sensors  71  in the wiring case  72 . 
     Note that in the case of this configuration, the first shields  41  and the second shields  42  of the respective individual sensors  71  are alternately aligned in the x direction. The magnetoelectric converter  25  of the individual sensor  71  has sensing directions of the magnetic field in the z direction and in the y direction. 
     Further, six individual sensors  71  are accommodated in the wiring case  72  shown in the previously shown  FIG.  17    to  FIG.  19    and the following figures. The number of the individual sensors  71  accommodated in the wiring case  72  is merely an example. As long as the wiring case  72  is capable of accommodating at least two individual sensors  71 , any number of individual sensors  71  may be accommodated in the wiring case  72 . 
     Further, a current sensor that detects a current in another in-vehicle equipment may be accommodated in the wiring case  72  of the second current sensor  12 . Further, it is possible to employ a configuration where the second current sensor  12  and the third current sensor  13  share a wiring case  72 , and the individual sensors  71  of the second current sensor  12  and the third current sensor  13  are accommodated in the same wiring case  72 . 
     &lt;Wiring Case&gt; 
     As shown in  FIG.  17   , the wiring case  72  has an integrated housing  73 , a terminal housing  74 , and an energization terminal  75 . The integrated housing  73  and the terminal housing  74  are made of an insulating resin material. The integrated housing  73  and the terminal housing  74  are integrally connected to each other. As shown in  FIG.  18    and  FIG.  19   , multiple individual sensors  71  are accommodated in the integrated housing  73 . Accordingly, the physical constitution of the integrated housing  73  is larger than the physical constitution of the sensor housing  50  of the individual sensor  71 . Multiple energization terminals  75  are insert-molded in the terminal housing  74 . As shown in  FIG.  20    to  FIG.  23   , one ends and the other ends of the multiple energization terminals  75  are exposed to the outside of the terminal housing  74 . 
     In  FIG.  20   , (a) shows a rear view of the wiring case; (b) shows a top view of the wiring case; and (c) shows a bottom view of the wiring case. In  FIG.  21   , (a) shows a left side view of the wiring case; (b) shows a top view of the wiring case; and (c) shows a right side view of the wiring case. Note that (b) of  FIG.  20    and (b) of  FIG.  21    show the same figure. 
     In  FIG.  22   , (a) shows a front view of the second current sensor; (b) shows a top view of the second current sensor; and (c) shows a bottom view of the second current sensor. In  FIG.  23   , (a) shows a side view of the second current sensor; and (b) shows a top view of the second current sensor. Note that (b) of  FIG.  22    and (b) of  FIG.  23    show the same figure. 
     As respectively shown in (c) of  FIG.  20    and (c) of  FIG.  22   , the wiring case  72  has an integrated wiring board  76 . The one end of the connection terminal  60  of the individual sensor  71  is connected to the integrated wiring board  76 . One end of the energization terminal  75  is connected to the integrated wiring board  76 . With this configuration, the individual sensor  71  and the energization terminal  75  are electrically connected to each other via the wiring pattern of the integrated wiring board  76 . The other end of the energization terminal  75  is electrically connected via a wire harness or the like to the MG ECU  802 . As described above, output of the individual sensor  71  is transmitted via the integrated wiring board  76 , the energization terminal  75 , and the wire harness, into the MG ECU  802 . The integrated wiring board  76  and the energization terminal  75  correspond to an input/output wiring. 
     As described above, the second current sensor  12  is provided on the first energization bus bar  341  and the second energization bus bar  342 . These energization bus bars are respectively divided into a part adjacent to the first inverter  320  and a part adjacent to the first motor  400 . The energization bus bar has a part to connect the first inverter  320  to the second current sensor  12  and a part to connect the second current sensor  12  to the first motor  400 . 
     In the energization bus bar of the present embodiment, the part to connect the first inverter  320  to the second current sensor  12  is provided by a conductive plate made of a metal material. The part of the energization bus bar to connect the second current sensor  12  to the first motor  400  is provided by a wire. In the following description, the part of the energization bus bar to connect the first inverter  320  to the second current sensor  12  will be simply referred to as the conductive plate. The part of the energization bus bar to connect the second current sensor  12  to the first motor  400  will be simply referred to as the wire. 
     Note that the form of the energization bus bar is arbitrarily modified in correspondence with respective shapes of the inverter and the motor, and in correspondence with mounting form of the inverter and the motor in the vehicle and the like. Accordingly, the specific form of the energization bus bar is not limited to the above-described example. In correspondence with form of the energization bus bar, the respective forms of the electrical-conduction bus bar  30  in the wiring case  72  and the individual sensor  71  are arbitrarily modified. Especially, the form of the electrical-conduction bus bar  30  in the individual sensor  71  can be modified only by changing the respective shapes of the first exposed part  32  and the second exposed part  33 . Accordingly, it is not necessary to modify the internal shape of the individual sensor  71 . With this configuration, it is not necessary to change a production line of the individual sensor  71 . 
     As shown in  FIG.  20    and  FIG.  21   , the integrated housing  73  has a bottom wall  77  and a peripheral wall  78 . The bottom wall  77  faces in the z direction. The planar shape of the bottom wall  77  is a rectangular shape with the x direction as a longitudinal direction. 
     The peripheral wall  78  rises in the z direction from an inner bottom surface  77   a  of the bottom wall  77  facing in the z direction. The peripheral wall  78  has a left wall  78   a  and a right wall  78   b  aligned in the x direction. The peripheral wall  78  has an upper wall  78   c  and a lower wall  78   d  aligned in the y direction. The left wall  78   a , the upper wall  78   c , the right wall  78   b , and the lower wall  78   d  are connected in sequence in the circumferential direction about the z direction. With this configuration, the peripheral wall  78  forms a cylindrical shape having an opening in the z direction. The multiple individual sensors  71  can be housed in the storage space provided by the bottom wall  77  and the peripheral wall  78 . 
     As shown in  FIG.  18   , the individual sensor  71  is inserted along the z direction into the storage space of the integrated housing  73 . As shown in  FIG.  19   , the multiple individual sensors  71  are aligned in the x direction in the storage space. 
     Similarly to the first current sensor  11 , the multiple individual sensors  71  each have the first shield  41  and the second shield  42 . The first shield  41  and the second shield  42  are opposed to and away from each other in the x direction. Accordingly, in the storage space, the first shields  41  and the second shields  42  of the multiple individual sensors are alternately aligned. 
     As shown in  FIG.  16   , the first exposed part  32  and the second exposed part  33  extend in the y direction from the sensor housing  50  of the individual sensor  71 . The upper wall  78   c  of the integrated housing  73  is formed with slits  78   e  for allowing the ends of the first exposed parts  32  of the sensor housings  50  of the individual sensors  71  accommodated in the storage space to be placed outside of the storage space. The slits  78   e  are each formed along the z direction from the apical surface of the upper wall  78   c  toward the bottom wall  77 . 
     In the stats where the individual sensor  71  is accommodated in the integrated housing  73 , the end of the first exposed part  32  of the individual sensor  71  is positioned via the slit  78   e  on the outside of the storage space. The end of the first exposed part  32  is electrically connected to the above-described conductive plate by laser welding or the like. 
     Further, a conductive terminal  79  is insert-molded in the bottom wall  77  of the integrated housing  73 . As shown in (b) of  FIG.  20    and (b) of  FIG.  21   , a part of the conductive terminal  79  is exposed from the inner bottom surface  77   a  of the bottom wall  77 . 
     In the state where the individual sensor  71  is accommodated in the integrated housing  73 , the second exposed part  33  of the individual sensor  71  is opposed to the part of the conductive terminal  79  exposed from the inner bottom surface  77   a . The second exposed part  33  and the conductive terminal  79  are electrically connected to each other by laser welding or the like. 
     Further, the integrated housing  73  has a terminal block  80  to support the multiple conductive terminals  79 . The terminal block  80  is formed integrally with the lower wall  78   d  adjacent to the bottom wall  77 . The terminal block  80  has a rectangular parallelepiped shape extending in the x direction. The multiple conductive terminals  79  are insert-molded also in the terminal block  80 . The multiple conductive terminals  79  are partly exposed from the terminal block  80 . The part of the conductive terminal  79  exposed from the terminal block  80  extends away from the terminal block  80  in the z direction. The part of the conductive terminal  79  exposed from the terminal block  80  opposes the lower wall  78   d  in the y direction. The parts of the multiple conductive terminals  79  exposed from the terminal block  80  are aligned with each other across spaces in the x direction. 
     The part of the conductive terminal  79  exposed from the terminal block  80  has a flat shape in which the thickness in the y direction is thin. The part of the conductive terminal  79  exposed from the terminal block  80  has an energization surface  79   a  facing in the y direction and its rear surface  79   b . In the conductive terminal  79 , a bolt hole  79   c  is formed to pass through from the energization surface  79   a  to the rear surface  79   b  in the y direction. 
     Further, the rear surface  79   b  of the conductive terminal  79  is provided with a nut  81  opened in the y direction. The opening of the nut  81  and the opening of the bolt hole  79   c  are aligned in the y direction. 
     A terminal of the wire is disposed on the energization surface  79   a  of the conductive terminal  79 . The terminal of the wire also has a bolt hole penetrating in the y direction. In the terminal of the wire, the surface on which the bolt hole is formed is opposed to the energization surface  79   a  of the conductive terminal  79 . In this state, a bolt shaft (not illustrated) is inserted through the bolt holes of the conductive terminal  79  and the terminal of the wire. Then, the end of the bolt shaft is fastened to the nut  81 . The bolt is fastened to the nut  81  from the end of the bolt shaft toward a bolt head. The conductive terminal  79  and the terminal of the wire are held between the bolt head and the nut  81 . With this configuration, the terminal of the wire and the conductive terminal  79  are brought into contact and electrically and mechanically connected to each other. As described above, the second exposed part  33  of the individual sensor  71  and the wire terminal are electrically connected to each other via the conductive terminal  79 . 
     The connection terminal  60  extends from the sensor housing  50  of the individual sensor  71  in the z direction. An insertion hole for allowing the one end of the connection terminal  60  to be placed on the outside of the storage space is formed in the bottom wall  77  of the integrated housing  73 . The insertion hole is formed to pass through from the inner bottom surface  77   a  of the bottom wall  77  to an outer bottom surface  77   b  on the rear side of the inner bottom surface  77   a . The one end of the connection terminal  60  protrudes, away from the outer bottom surface  77   b  via the insertion hole, to the outside of the storage space. Since the insertion hole is a minute hole, it is not shown in the figure. 
     The terminal housing  74  is aligned with the integrated housing  73  in the x direction. The terminal housing  74  is connected integrally with the left wall  78   a  of the integrated housing  73 . The terminal housing  74  extends in the z direction. The terminal housing  74  has an upper surface  74   a  and a lower surface  74   b  aligned in the z direction. 
     The multiple energization terminals  75  insert-molded in the terminal housing  74  extend in the z direction. One end of the energization terminal  75  projects from the lower surface  74   b  of the terminal housing  74 . The other end of the energization terminal  75  projects from the upper surface  74   a  of the terminal housing  74 . 
     As shown in (a) and (c) of  FIG.  20   , the outer bottom surface  77   b  of the bottom wall  77  of the integrated housing  73  and the lower surface  74   b  of the terminal housing  74  continuous each other in the x direction and the y direction. The integrated wiring board  76  is provided on the outer bottom surface  77   b  and the lower surface  74   b , which are continuous to each other. 
     The integrated wiring board  76  has a flat shape in which the thickness in the z direction is thin. The integrated wiring board  76  has a mounting surface  76   a  facing in the z direction and a rear surface  76   b . The integrated wiring board  76  is fixed, in a state where the mounting surface  76   a  opposes respectively to the outer bottom surface  77   b  and the lower surface  74   b  in the z direction, to the integrated housing  73  and the terminal housing  74 . 
     As described above, the one end of the energization terminal  75  projects from the lower surface  74   b . The one end of the connection terminal  60  projects from the outer bottom surface  77   b . On the other hand, a first through hole  76   c  is formed in the integrated wiring board  76  to receive the one end of the energization terminal  75 . A second through hole  76   d  is formed in the integrated wiring board  76  to receive the one end of the connection terminal  60 . The first through hole  76   c  and the second through hole  76   d  penetrate the integrated wiring board  76  from the mounting surface  76   a  to the rear surface  76   b  in the z direction. Further, a wiring pattern which electrically connects the first through hole  76   c  to the second through hole  76   d  is formed on the integrated wiring board  76 . 
     The integrated wiring board  76  is arranged on the outer bottom surface  77   b  and the lower surface  74   b  such that the one end of the energization terminal  75  is inserted into the first through hole  76   c . Then, the first through hole  76   c  and the energization terminal  75  are electrically connected to each other via solder or the like. 
     The individual sensor  71  is arranged in the storage space such that the one end of the connection terminal  60  is inserted through the insertion hole of the bottom wall  77  and the second through hole  76   d . Then, the second through hole  76   d  and the connection terminal  60  are electrically connected to each other via solder or the like. As described above, the connection terminal  60  of the individual sensor  71  is electrically connected via the second through hole  76   d , the wiring pattern on the integrated wiring board  76 , and the first through hole  76   c , to the energization terminal  75 . 
     The wiring case  72  has multiple flanges  82  for mounting the second current sensor  12  in the vehicle. The multiple flanges  82   a  each have a bolt hole  82   a  for bolt-fixing the second current sensor  12  to the vehicle. 
     The wiring case  72  of the present embodiment has three flanges  82 . One of the three flanges  82  is formed on the bottom wall  77  adjacent to the right wall  78   b . One of the remaining two flanges  82  is formed on the terminal housing  74  adjacent to the lower wall  78   d . This flange  82  is connected integrally with the terminal block  80 . The remaining one flange  82  is formed on the opposite side to the connection part of the terminal housing  74  to the integrated housing  73 . 
     As described above, the two of the three flanges  82  are aligned via the integrated housing  73  and the terminal housing  74  in the x direction. The remaining one flange  82  is away from the two flanges  82  that are aligned in the x direction, in the y direction. In this manner, the three flanges  82  form apexes of a triangle. 
     As described above, the one end of the connection terminal  60  projects from the outer bottom surface  77   b , and the one end of the energization terminal  75  projects from the lower surface  74   b . Further, the integrated wiring board  76  is disposed on the outer bottom surface  77   b  and the lower surface  74   b . To avoid contacts with the vehicle of the one end of the connection terminal  60 , the one end of the energization terminal  75 , and the integrated wiring board  76 , the three flanges  82  each have a leg  83  extending in the z direction. In the state where the second current sensor  12  is mounted in the vehicle, the one end of the connection terminal  60 , the one end of the energization terminal  75 , and the integrated wiring board  76  are separated from the vehicle, with the legs  83 , in the z direction. 
     &lt;Advantageous Effects of Current Sensor&gt; 
     Next, the advantageous effects of the current sensor according to the present embodiment will be described. As described above, the first current sensor  11  and the individual sensor  71  of the second current sensor  12  and third current sensor  13  have equivalent configurations. Accordingly, the respective sensors achieve the similar advantageous effects. In the following description, to avoid complications, the first current sensor  11  and the individual sensor  71  are not discriminated but merely referred to as a current sensor. The degradation of detection accuracy to detect the current is suppressed with the following various advantageous effects. 
     &lt;Magnetic Saturation of Shield&gt; 
     As described above, in the first opposite end part  41   e  of the first shield  41 , the length in the x direction is shorter than that of the first center part  41   d . Accordingly, entrance of magnetic field into the first opposite end part  41   e  is suppressed. The permeation of magnetic field through the portions of the first center part  41   d , directly connected to and aligned with the first opposite end part  41   e  in the y direction (parallel portions), from one to the other of the two ends of the first both end part  41   e , is suppressed. As a result, magnetic saturation in the parallel portions of the first center part  41   d  is suppressed. Leakage of electromagnetic noise from the first center part  41   d  is suppressed. 
       FIG.  24    shows, by schematically hatching, a region of the first shield  41  easily magnetically saturated by magnetic field permeation. In  FIG.  24   , (a) schematically shows the magnetic saturation occurring in the first shield without notch as a comparative configuration; and (b) schematically shows a magnetically saturated region of the first shield  41  according to the present embodiment. In  FIG.  24   , a bold solid arrow indicates a current which flows through the electrical-conduction bus bar  30 . 
     As shown in the figure, in the first shield without notch, magnetic saturation uniformly and easily occurs. On the other hand, in the first shield  41  in which the notches  41   c  are formed, even when magnetic saturation occurs in a region other than the parallel portions of the first center part  41   d , the occurrence of magnetic saturation is suppressed in the parallel portions. 
       FIG.  25    shows a simulation result of distribution of the magnetic field which permeates the shield. In  FIG.  25   , (a) shows the magnetic field distribution in a cross section along an XXVa-XXVa line shown in  FIG.  24   ; and (b) shows the magnetic field distribution in a cross section along an XXVb-XXVb line shown in  FIG.  24   . 
     Note that in  FIG.  25   , (a) shows a simulation result when the first shield  41  and the second shield  42  each have a rectangular shape; and (b) shows a simulation result when the notches  41   c  are formed in the first shield  41  and the second shield  42 . The intensity of the magnetic field is expressed with coarseness/fineness of hatching. As the coarseness of the hatching is increased, the intensity of the magnetic field becomes lower, while as the fineness of the hatching is increased, the intensity of the magnetic field becomes higher. 
     As it is obvious from the simulation result, when the notch  41   c  is omitted, the magnetic field distributions in the first shield and the second shield are uniform. The intensities of the respective entire magnetic fields in the first shield and the second shield are high. On the other hand, when the notches  41   c  are formed, the intensities of the respective entire magnetic fields in the first shield and the second shield are low. Especially, the intensities of magnetic field distributions in the respective parallel portions in the first center part  41   d  and the second center part  42   d  are low. With this configuration, the leakage of the electromagnetic noise from the first center part  41   d  and the second center part  42   d  by the magnetic saturation is suppressed. 
     Note that as shown in  FIG.  25   , the intensities of the respective magnetic field distributions in the first shield  41  and the second shield  42  are different. The difference is caused since the distance between the first shield  41  and the electrical-conduction bus bar  30  and the distance between the second shield  42  and the electrical-conduction bus bar  30  are different. In both of the magnetic field distributions, the intensity is low in the parallel portions, while the intensity is high in the other region than the parallel portions. 
     The parallel portions of the first center part  41   d  where the magnetic saturation is suppressed, and the first sensing unit  21  and the second sensing unit mounted on the wiring board  20 , are aligned in the z direction. Accordingly, the input of the electromagnetic noise, leaked by the magnetic saturation in the first center part  41   d , into the magnetoelectric converter  25  of the first sensing unit  21  and the second sensing unit  22 , is suppressed. 
     &lt;Misalignment of Shield&gt; 
     The first shield  41  is mounted on the shield support pin  57   a , and fixed via the shield adhesive  57   e  to the shield adhesion pin  57   b . The second shield  42  is mounted on the shield support pin  57   a , and fixed via the shield adhesive  57   e  to the base  51 . 
     With this configuration, the misalignment of the first shield  41  and the misalignment of the second shield  42  respectively with respect to the sensor housing  50  do not depend on the shape variation of the shield adhesive  57   e  having fluidity upon the adhesion fixing any longer. The misalignment of the first shield  41  and the misalignment of the second shield  42  respectively with respect to the sensor housing  50  are caused by the manufacturing error of the sensor housing  50 . It is possible to shift the factor of the misalignment of the first shield  41  and the misalignment of the second shield  42  respectively with respect to the wiring board  20  fixed to the sensor housing  50  to the manufacturing error of the sensor housing  50 . As a result, it is possible to suppress reduction of input suppression of electromagnetic noise caused by the first shield  41  and the second shield  42  into the magnetoelectric converter  25 . 
     The temperature of the shield adhesive  57   e  upon the adhesion fixing of the first shield  41  and the second shield  42  respectively to the sensor housing  50  is set to be higher than the temperature of the environment where the current sensor is provided. The shield adhesive  57   e  is cooled down to the room temperature and is thus solidified. With this configuration, in the shield adhesive  57   e , a residual stress condensing to its own center occurs at the temperature of the environment where the first current sensor is provided. The contact state between the first shield  41  and the shield support pin  57   a  and the contact status between the second shield  42  and the shield support pin  57   a  are respectively maintained. 
     With this configuration, the displacement of the first shield  41  and the displacement of the second shield  42  respectively with respect to the sensor housing  50  in the z direction are suppressed. In other words, the displacement of the first shield  41  and the displacement of the second shield  42  respectively with respect to the wiring board  20  fixed to the sensor housing  50  in the z direction are suppressed. With this configuration, the reduction of input suppression of electromagnetic noise, cased in the first shield  41  and the second shield  42  into the magnetoelectric converter  25 , is suppressed. 
     &lt;Misalignment of Wiring Board&gt; 
     The wiring board  20  is mounted on the board support pin  56   a  and is fixed via the board adhesive  56   e  to the board adhesion pin  56   b.    
     With this configuration, the misalignment of the wiring board  20  with respect to the sensor housing  50  does not depend on the shape variation of the board adhesive  56   e  having fluidity upon the adhesion fixing any longer. The misalignment of the wiring board  20  with respect to the sensor housing  50  is caused by the manufacturing error of the sensor housing  50 . It is possible to shift the factor of the misalignment of the wiring board  20  with respect to the electrical-conduction bus bar  30  fixed to the sensor housing  50  to the manufacturing error of the sensor housing  50 . As a result, the variation of the measurement current which permeates the magnetoelectric converter  25  mounted on the wiring board  20  is suppressed. 
     The temperature of the board adhesive  56   e  upon the adhesion fixing of the wiring board  20  to the sensor housing  50  is set to be higher than the temperature of the environment where the current sensor is provided. The board adhesive  56   e  is cooled down to the room temperature and is thus solidified. With this configuration, in the board adhesive  56   e , a residual stress condensing to its own center occurs at the temperature of the environment where the current sensor is provided. The contact status between the wiring board  20  and the board support pin  56   a  is maintained with the residual stress. 
     With this configuration, the displacement of the wiring board  20  with respect to the sensor housing  50  in the z direction is suppressed. In other words, the displacement of the wiring board  20  with respect to the electrical-conduction bus bar  30  fixed to the sensor housing  50  in the z direction is suppressed. With this configuration, the variation of the measurement current which permeates the magnetoelectric converter  25  mounted on the wiring board  20  is suppressed. 
     &lt;Manufacturing Error of Wiring Board&gt; 
     The first sensing unit  21  and the second sensing unit  22  are provided on the opposing surface  20   a  of the wiring board  20  with respect to the electrical-conduction bus bar  30 . With this configuration, the distances between the first sensing unit  21  and the electrical-conduction bus bar  30  and between the second sensing unit  22  and the electrical-conduction bus bar  30  in the z direction do not depend on the thickness of the wiring board  20  in the z direction any longer. The variation of the distances between the sensing units and the electrical-conduction bus bar  30  in the z direction, due to the manufacturing error of the thickness of the wiring board  20  in the z direction, is suppressed. 
     &lt;Separation of Wiring Case and Individual Sensor&gt; 
     In a case where an electrical-conduction bus bar is fixed to a housing made of an insulating resin material, misalignment occurs in the bus bar with respect to the housing due to a manufacturing error of the housing or time deterioration such as creep of the housing. The larger the physical constitution of the housing is, the larger the misalignment is. 
     As described above, the second current sensor  12  and the third current sensor  13  have the integrated housing  73 , the physical constitution of which is larger than that of the sensor housing  50  of the current sensor (individual sensor  71 ). The current sensor is accommodated in the integrated housing  73 . The electrical-conduction bus bar  30  is fixed, not to the integrated housing  73  having the large physical constitution, but to the sensor housing  50 . The magnetoelectric converter  25  detects the current which flows through the electrical-conduction bus bar  30 . 
     According to the configuration, the occurrence of relative misalignment between the electrical-conduction bus bar  30  and the magnetoelectric converter  25 , due to the above-described manufacturing error of the housing or time deterioration such as creep of the housing, is suppressed. 
     Second Embodiment 
     Next, a second embodiment will be described with reference to  FIG.  26    and  FIG.  27   . The current sensors of the following respective embodiments have many points common to the above-described embodiment. Accordingly, in the following descriptions, explanation of the common parts will be omitted, and the differences will be mainly explained. Further, in the following descriptions, the constituent elements the same as the constituent elements shown in the above-described embodiment will have the same reference numerals. 
     &lt;Extending Part at Both Ends&gt; 
     In the first embodiment, the example where the second shield  42  has the extending parts  42   c , which extends in the z direction, at the two sides  42   f  aligned in the x direction and adjacent to the second center part  42   d  has been shown. In the present embodiment, as shown in  FIG.  26   , in the second shield  42 , the extending parts  42   c  are formed at the two sides  42   f  and adjacent to second opposite end parts  42   e . In  FIG.  26   , (a) is a perspective view for explaining the arrangement of the shield, the magnetoelectric converter, and the electrical-conduction bus bar; and (b) is a side view for explaining the arrangement of the shield, magnetoelectric converter, and the electrical-conduction bus bar. 
     With this configuration, the magnetoelectric field entered the second shield  42  easily permeates via the extending parts  42   c  formed at the second opposite end parts  42   e  in the first shield  41 . As schematically shown in  FIG.  27   , in the first shield  41 , the permeation pathway is adjacent to the first opposite end parts  41   e . Similarly, the permeation pathway of the magnetic field in the second shield  42  is adjacent to the second opposite end parts  42   e.    
     In  FIG.  27   , a bold solid arrow indicates the current which flows through the electrical-conduction bus bar  30 ; a solid arrow indicates the magnetic field which permeates the first shield  41 ; and a broken arrow indicates the magnetic field which permeates the second shield  42 . In the figure, an enclosed middle dot symbol indicates the magnetic field which directs from the second shield  42  toward the first shield  41  in the z direction; and an enclosed cross symbol indicates the magnetic field which directs from the first shield  41  toward the second shield  42  in the z direction. 
     Accordingly, the electromagnetic noise entered the second shield  42  hardly flows via the second center part  42   d  to the first shield  41 . Similarly, the electromagnetic noise entered the first shield  41  hardly permeates via the first center part  41   d  to the second shield  42 . 
     The second center part  42   d  and the first center part  41   d  are hardly magnetically saturated respectively. As a result, the leakage of the magnetic field respectively from the second center part  42   d  and the first center part  41   d  due to magnetic saturation is suppressed. 
     Further, as clearly indicated in (b) of  FIG.  26   , the magnetoelectric converters  25  of the first sensing unit  21  and the second sensing unit  22  are positioned between the two extending parts  42   c  in the y direction. That is, the magnetoelectric converters  25  are positioned between the second center part  42   d  and the first center part  41   d  in the z direction. Accordingly, input of the magnetic field, leaked respectively due to magnetic saturation of the second center part  42   d  and the first center part  41   d , into the magnetoelectric converters  25 , is suppressed. As a result, the degradation of accuracy in the measurement current detection is suppressed. 
     In the present embodiment, the example where the extending part  42   c  is formed respectively on the second opposite end parts  42   e  of the two sides  42   f  of the second shield  42  has been shown. However, as shown in (a) of  FIG.  28   , for example, a configuration where the extending part  42   c  is also formed on the second center part  42   d  of the two sides  42   f  of the second shield  42  may be employed. Note that in the extending part  42   c  formed on the second center part  42   d , the length in the z direction is shorter than that of the extending part  42   c  formed on the second opposite end parts  42   e . With this configuration, the magnetic field entered the shield  40  permeates the end part more easily than the center part. 
     Further, as shown in (b) of  FIG.  28   , a configuration where the extending part  42   c  is formed on the second opposite end parts  42   e  of one of the two sides  42   f , and the extending part  42   c  is formed on the second opposite end parts  42   e  and the second center part  42   d  of the other one of the two sides  42   f , may be employed. Note that in the other one of the two sides  42   f , the lengths of the extending parts  42   c , formed on the second opposite end parts  42   e  and the second center part  42   d , in the z direction, are the same. With this configuration, the magnetic field entered the shield  40  also permeates the end part more easily than the center part. In  FIG.  28   , (a) and (b) shows a perspective view for explaining the arrangement of the shield, the magnetoelectric converter, and the electrical-conduction bus bar. 
     Further, as shown in (a) of  FIG.  29   , a configuration where the extending part  42   c  is formed on one of the two second opposite end parts  42   e  of one of the two sides  42   f , and on the other one of the two second opposite end parts  42   e  of the other one of the two sides  42   f , may be employed. The extending part  42   c  formed on one of the two sides  42   f  and the extending part  42   c  formed on the other one of the two sides  42   f  are away from each other respectively in the y direction and in the x direction. 
     Further, a configuration where the extending part  42   c  is formed on the first shield  41  in addition to the second shield  42  may be employed. The first shield  41  has two opposing sides  41   f  aligned in the x direction. For example, as shown in (b) of  FIG.  29   , a configuration where the extending parts  42   c  are formed on the first opposite end parts  41   e  of the two opposing sides  41   f  in the first shield  41  may be employed. In  FIG.  29   , (a) and (b) show a perspective view for explaining the arrangement of the shield, magnetoelectric converter, and the electrical-conduction bus bar. 
     As the form of the extending part  42   c  which can be formed on the first shield  41 , a form equivalent to the extending part  42   c  formed on the second shield  42  shown above may be employed. The extending part  42   c  formed on the first shield  41  corresponds to an extension part. 
     Note that the current sensor according to the present embodiment and the following embodiments include constituent elements equivalent to the constituent elements of the current sensor described in the first embodiment. Therefore, it goes without saying that the current sensor according to the present embodiment and the following embodiments achieve the similar advantageous effects. 
     Third Embodiment 
     Next, a third embodiment will be described based on  FIG.  30    to  FIG.  32   . 
     &lt;Stress Relaxation Member&gt; 
     In the present embodiment, a stress relaxation member  34  is formed in the electrical-conduction bus bar  30  of the first current sensor  11 . The stress relaxation member  34  is formed in the first exposed part  32  and the second exposed part  33  of the electrical-conduction bus bar  30 . 
     As described above, the electrical-conduction bus bar  30  has the covered part  31  covered with the sensor housing  50 . The first exposed part  32  and the second exposed part  33  are respectively exposed from the sensor housing  50 , and connected integrally with the covered part  31 . The bolt hole  30   c  for electrical and mechanical connection with the energization bus bar  307  via the bolt is formed respectively in the first exposed part  32  and the second exposed part  33 . The stress relaxation member  34  is formed respectively in the connection parts between the first exposed part  32  and the covered part  31  and between the second exposed part  33  and the covered part  31 , and in the connection parts between the first exposed part  32  and the forming part of the bolt hole  30   c  and between the second exposed part  33  and the forming part of the bolt hole  30   c.    
     As shown in  FIG.  31   , the stress relaxation member  34  is locally bent from the rear surface  30   b  of the electrical-conduction bus bar  30  toward the front surface  30   a . With this bending, the stress relaxation member  34  is elastically deformable by bending with respect to a force in the z direction applied to the electrical-conduction bus bar  30 . In  FIG.  31   , the stress relaxation member  34  is bent like a weaving at once. The number of times of waving and the bending form are not limited to the above described example. 
     As described above, the electrical-conduction bus bar  30  is bolt-fixed to the energization bus bar  307 . The energization bus bar  307  of the present embodiment corresponds to a first terminal block  307   a  and a second terminal block  307   b  shown in  FIG.  32   . The electrical-conduction bus bar  30  is bolt-fixed to the first terminal block  307   a  and the second terminal block  307   b . With this configuration, the first terminal block  307   a  and the second terminal block  307   b  are bridged with the energization bus bar  307 . The first terminal block  307   a  and the second terminal block  307   b  are electrically connected to each other via the energization bus bar  307 . Note that in the following description, as shown in  FIG.  32   , the bolt inserted through the bolt hole  30   c  of the electrical-conduction bus bar  30  is denoted by a reference numeral  307   c . The first terminal block  307   a  and the second terminal block  307   b  correspond to an external energization unit. 
     The first terminal block  307   a  has a first mounting surface  307   d  facing in the z direction. Similarly, the second terminal block  307   b  has a second mounting surface  307   e  facing in the z direction. A fastening hole  307   f  for fastening the shaft of the bolt  307   c  is formed in each of the first mounting surface  307   d  and the second mounting surface  307   e . The fastening holes  307   f  are opened in the first mounting surface  307   d  and the second mounting surface  307   e . The fastening hole  307   f  extends in the z direction. In  FIG.  32   , (a) shows a case where the positions of the first mounting surface and the second mounting surface in the z direction correspond with each other; and (b) shows a case where the positions of the first mounting surface and the second mounting surface in the z direction do not correspond with each other. 
     The rear surface  30   b  of the first exposed part  32  opposes to the first mounting surface  307   d  in the z direction. The rear surface  30   b  of the second exposed part  33  opposes to the second mounting surface  307   e  in the z direction. In this state, the first current sensor  11  is provided on the first terminal block  307   a  and the second terminal block  307   b.    
     As shown in (a) of  FIG.  32   , when the positions of the first mounting surface  307   d  and the second mounting surface  307   e  in the z direction correspond with each other, the rear surface  30   b  of the first exposed part  32  is in contact with the first mounting surface  307   d , and the rear surface  30   b  of the second exposed part  33  is in contact with the second mounting surface  307   e . In this contact state, the end of the shaft of the bolt  307   c  is inserted into the bolt hole  30   c  of the electrical-conduction bus bar  30  and the fastening hole  307   f  of the terminal block along the z direction. Then, the bolt  307   c  is fastened to the terminal block so as to bring the head of the bolt  307   c  closer to the first mounting surface  307   d  (second mounting surface  307   e ). The first exposed part  32  and the second exposed part  33  are held between the head of the bolt  307   c  and the terminal block. With is configuration, the first current sensor  11  is mechanically and electrically connected to the terminal block. 
     On the other hand, as shown in (b) of  FIG.  32   , when the positions of the first mounting surface  307   d  and the second mounting surface  307   e  in the z direction do not correspond with each other, upon contact between the rear surface  30   b  of the first exposed part  32  and the first mounting surface  307   d , the rear surface  30   b  of the second exposed part  33  is not in contact with the second mounting surface  307   e . The second mounting surface  307   e  and the rear surface  30   b  of the second exposed part  33  are away from each other in the z direction, and a gap is formed between the second mounting surface  307   e  and the rear surface  30   b.    
     In this separated state, when the shaft of the bolt  307   c  is inserted in the bolt hole  30   c  and the fastening hole  307   f  and the head of the bolt  307   c  is brought into contact with the front surface  30   a  of the second exposed part  33 , a force toward the z direction acts on the second exposed part  33 . 
     As described above, to enhance the intensity of the measurement current which permeates the magnetoelectric converter  25 , the narrow part  31   a  in which the length in the x direction is locally short is formed in the covered part  31 . Since the length of the narrow part  31   a  in the x direction is short, the rigidity of the narrow part  31   a  is lower than that of other parts. The narrow part  31   a  can be easily deformed. 
     Accordingly, when the force toward the z direction upon fastening of the bolt  307   c  acts on the second exposed part  33  as described above, there is a fear of deformation of the narrow part  31   a  due to the force. There is a fear of position displacement of the narrow part  31   a  in the sensor housing  50 . Even when the narrow part  31   a  is not formed in the covered part  31 , there is a fear of position displacement of the covered part  31  in the sensor housing  50 . With the position displacement, there is a fear of change of distribution of the measurement current which permeates the magnetoelectric converter  25 . 
     As described above, the stress relaxation member  34  is formed in each of the first exposed part  32  and the second exposed part  33 . Accordingly, with the above-described positional difference in the z direction between the first mounting surface  307   d  and the second mounting surface  307   e , even when there is a gap between the second mounting surface  307   e  and the rear surface  30   b  of the second exposed part  33 , the stress relaxation member  34  is elastically deformed in correspondence with the force of the bolt  307   c  in the z direction. With this configuration, the deformation of the narrow part  31   a  is suppressed. The position displacement of the narrow part  31   a  in the sensor housing  50  is suppressed. As a result, the change of the distribution of the measurement current which permeates the magnetoelectric converter  25  is suppressed. The degradation of accuracy in the measurement current detection is suppressed. 
     Note that the length (thickness) of the stress relaxation member  34  between the front surface  30   a  and the rear surface  30   b  is equal to the respective thicknesses of the covered part  31 , the first exposed part  32 , and the second exposed part  33 . With this configuration, different from a configuration where, e.g. the thickness of the stress relaxation member is locally thin in comparison with the thicknesses of the covered part and the exposed part, local heat generation in the stress relaxation member  34  by the current energization is suppressed. As a result, life reduction of the electrical-conduction bus bar  30  is suppressed. 
     Fourth Embodiment 
     Next, a fourth embodiment will be described with reference to  FIG.  33    to  FIG.  35   . In  FIG.  33   , (a) shows a top view of the electrical-conduction bus bar; and (b) shows a side view of the electrical-conduction bus bar. In  FIG.  34   , (a) shows the position of the wiring board  20  on which the respective magnetoelectric converters  25  of the first sensing unit  21  and the second sensing unit  22  are mounted and the position of the electrical-conduction bus bar  30 ; (b) shows displacement of the wiring board  20  with respect to the electrical-conduction bus bar  30 ; and (c) shows a magnetic field which permeates the respective magnetoelectric converters  25  of the first sensing unit  21  and the second sensing unit  22 . 
     &lt;Difference Cancellation&gt; 
     In the first embodiment, the example where the respective magnetoelectric converters  25  of the first sensing unit  21  and the second sensing unit  22  are aligned in the y direction has been shown. In the present embodiment, as indicated with a broken line in  FIG.  33   , the respective magnetoelectric converters  25  of the first sensing unit  21  and the second sensing unit  22  are aligned in the x direction. The magnetoelectric converter  25  of the first sensing unit  21  corresponds to a first magnetoelectric converter. The magnetoelectric converter  25  of the second sensing unit  22  corresponds to a second magnetoelectric converter. 
     The two magnetoelectric converters  25  are symmetrically arranged via the symmetry axis AS. The positions of the two magnetoelectric converters  25  in the y direction and the position of the symmetry axis AS (center point CP) in the y direction are the same. Accordingly, the two magnetoelectric converters  25  are aligned via the center point CP in the x direction. 
     Further, the distances between the two magnetoelectric converters  25  and the covered part  31  in the z direction are the same. The covered part  31  and the narrow part  31   a  form a line-symmetrical shape via the symmetry axis AS. Accordingly, measurement currents, having different z-direction components but equivalent x-direction components, permeate the two magnetoelectric converters  25 . The absolute values of electric signals outputted from the two magnetoelectric converters  25  are equivalent to each other. 
     As described above, the covered part  31  is covered with the base  51  of the sensor housing  50 . The wiring board  20  on which the two magnetoelectric converters  25  are mounted is mounted on the board support pin  56   a  formed on the sensor housing  50 . Accordingly, the displacement of the wiring board  20  in the z direction is regulated with the board support pin  56   a.    
     However, the wiring board  20  is fixed via the board adhesive  56   e  to the board adhesion pin  56   b . In the board adhesive  56   e , time deterioration such as creep or expansion due to change of the environmental temperature may occur. There is a fear of displacement of the wiring board  20  relatively in the x direction and the y direction with respect to the covered part  31 . 
     When the wiring board  20  is displaced in the y direction, with the above-described symmetrical arrangement of the two magnetoelectric converters  25  in the x direction, the x-direction component of the measurement currents which permeate the two magnetoelectric converters  25  is not changed. However, as shown in  FIG.  34   , when the wiring board  20  is displaced in the x direction, the x-direction component of the measurement currents which permeate the two magnetoelectric converters  25  is changed. As a result, the absolute values of the electric signals outputted from the two magnetoelectric converters  25  are not equivalent to each other any longer. 
     In  FIG.  34   , a broken line indicates the placement locations of the two magnetoelectric converters  25  with respect to the electrical-conduction bus bar  30 . An alternate long and short dash line indicates the symmetry axis AS passing through the center point CP of the electrical-conduction bus bar  30 . An alternate long and two short dashes line indicates the positions of the two magnetoelectric converters  25  displaced with respect to the electrical-conduction bus bar  30 . An outlined arrow indicates the direction of the displacement of the wiring board  20  on which the two magnetoelectric converters  25  are mounted, caused with the board adhesive  56   e , with respect to the electrical-conduction bus bar  30 . In (a) and (b) of  FIG.  34   , a solid arrow indicates the magnetic field which passes through the magnetoelectric converter  25 . In (c) of  FIG.  34   , a solid arrow indicates the direction of change of the magnetic field which permeates the magnetoelectric converter  25 . 
     As described above, both of the two magnetoelectric converters  25  are mounted on the wiring board  20 . Even when the relative positions of the wiring board  20  and the covered part  31  in the x direction are changed by deformation of the board adhesive  56   e  as described above, the relative distance between the two magnetoelectric converters  25  mounted on the wiring board  20  is not changed. Accordingly, when the relative positions of the wiring board  20  and the covered part  31  are changed in the x direction by the deformation of the board adhesive  56   e , one of the two magnetoelectric converters  25  is closer to the symmetry axis AS, while the other one of the two magnetoelectric converters  25  is away from the symmetry axis AS. The perspective distances are equivalent to each other. In (b) of  FIG.  34   , the perspective distance is denoted by A. 
     As shown in (c) of  FIG.  34   , the measurement current which permeates one of the two magnetoelectric converters  25  is reduced, while the measurement current which permeates the other one of the two magnetoelectric converters  25  is increased. It is expected that the decrement and the increment of the measurement currents which permeate the two magnetoelectric converters  25  become equivalent to each other. In (b) of  FIG.  34   , the change amount of the measurement current is indicated as AB. 
     In the present embodiment, the polarity of the electric signals outputted from the two magnetoelectric converters  25  is inverted. The inversion of the polarity is realized by, for example as shown in  FIG.  35   , reversing the arrangement of the first magnetoresistive effect element  25   a  and the second magnetoresistive effect element  25   b  in the two magnetoelectric converters  25 . Otherwise, it is possible to invert the polarity of the two electric signals by, more simply, reversing the inverted input terminal and the non-inverted input terminal of the differential amplifier  25   c  shown in  FIG.  7    in the first sensing unit  21  and the second sensing unit  22 . 
     As described above, the electric signals, having absolute values of increment/decrement equivalent to each other, and different polarities, are outputted from the two magnetoelectric converters  25 . The two electric signals generated respectively with the first current sensor  11  are inputted into the battery ECU  801 . The two electric signals generated in the second current sensor  12  and the third current sensor  13  are inputted into the MG ECU  802 . 
     The battery ECU  801  and the MG ECU  802  take the difference between the two electric signals. Assuming that the absolute values of the electric signals outputted from the two magnetoelectric converters  25  are B, and that the absolute values of change amounts of the electric signals due to the displacement are ΔB, as the difference processing, B+ΔB−(−(B−ΔB))=2B holds. Otherwise, as the difference processing, B−ΔB−(−(B+ΔB))=2B holds. “+” corresponds to one of the first polarity and the second polarity, and “−” corresponds to the other one of the first polarity and the second polarity. 
     The decrement and the increment of the electric signal caused by the change of the relative positions of the wiring board  20  and the covered part  31  due to the above-described deformation of the board adhesive  56   e  are cancelled by performing the difference processing in this manner. The battery ECU  801  and the MG ECU  802  correspond to a difference part. 
     Note that as shown in  FIG.  36   , for example, a configuration where a difference circuit  29  to take the difference between the outputs from the two magnetoelectric converters  25  is mounted on the wiring board  20  may be employed. The first output wiring  20   d  and the second output wiring  20   e  are connected to the inverted input terminal and the non-inverted input terminal of the difference circuit  29 . In this case, the difference circuit  29  corresponds to the difference part. 
     The above-described change of the relative positions of the wiring board  20  and the covered part  31  in the x direction may be caused, not only by the above-described deformation of the board adhesive  56   e , but also by vibration by external stress which acts on the vehicle or driving of the engine  600  and the like. However, even when the relative positions of the wiring board  20  and the covered part  31  in the x direction are changed by these factors, the difference between the two electric signals outputted from the two magnetoelectric converters  25  is taken as described above. With this configuration, the decrement and the increment of the electric signals by change of the relative positions of the wiring board  20  and the covered part  31  are cancelled. Accordingly, the degradation of detection accuracy of the measurement magnetic field is suppressed. 
     Fifth Embodiment 
     Next, a fifth embodiment will be described with reference to  FIG.  37    and  FIG.  38   . 
     &lt;Anisotropy of Magnetic Permeability&gt; 
     In the first embodiment, the example where the first shield  41  and the second shield  42  are respectively manufactured by press-joining multiple flat plates made of a soft magnetic material has been shown. In the present embodiment, the first shield  41  and the second shield  42  are respectively manufactured by rolling magnetic steel. 
     As described in the first embodiment, it is possible to provide the magnetic permeability of the shield with anisotropy by specifying the rolling direction of the magnetic steel. In the present embodiment, the rolling direction of the first shield  41  and the second shield  42  is along the z direction. With this configuration, the magnetic permeability of the first shield  41  and the second shield  42  has anisotropy. Note that the manufacturing method of the first shield  41  and the second shield  42  is not limited to the above-described example. The first shield  41  and the second shield  42  may be manufactured with a material, the magnetic permeability of which has anisotropy. Further, it may be configured such that the magnetic permeability of one of the first shield  41  and the second shield  42  has anisotropy. 
     As described in  FIG.  37   , in the second current sensor  12  and the third current sensor  13 , the respective individual sensors  71  are aligned in the x direction. The first shield  41  and the second shield  42  of the respective individual sensors  71  are alternately aligned in the x direction. In this configuration, the directions of the magnetic-field detection of the magnetoelectric converters  25  of the individual sensor  71  are the z direction and the y direction. Note that a configuration where, in two individual sensors  71  aligned in the x direction, the first shield  41  of the one of the two individual sensors  71  and the second shield  42  of the other one of the two individual sensors  71  may be bundled together as one may be employed. 
     In the configuration where the multiple individual sensors  71  are aligned in the x direction, the measured magnetic field emitted from the electrical-conduction bus bar  30  of one individual sensor  71  becomes external noise to the other individual sensor(s)  71 . The external noise is formed in a ring shape in a plane regulated with the x direction and the z direction about the electrical-conduction bus bar  30 . The external noise has components along the x direction and the z direction. In this manner, in the environment of the configuration, the external noise along the x direction and the z direction easily permeates the individual sensor  71 . 
       FIG.  37    shows two individual sensors  71 . The measurement current flows through one of the two individual sensor  71  having the electrical-conduction bus bar  30  with an enclosed cross symbol. The measured magnetic field is emitted from this electrical-conduction bus bar  30 . To the adjacent individual sensor  71 , the measured magnetic field emitted from the electrical-conduction bus bar  30  with the enclosed cross symbol is electromagnetic noise.  FIG.  37    indicates the magnetic field with an arrow. 
     As described above, the first shield  41  and the second shield  42  respectively have anisotropy in the z direction. Accordingly, the component of the external noise along the z direction attempts to enter the first shield  41  and the second shield  42  respectively. On the other hand, the component of the external noise along the x direction does not depend on the anisotropy of the first shield  41  and the second shield  42  any longer. The component along the x direction attempts to permeate the magnetoelectric converter  25 . 
     For example, when the magnetic field indicated with a broken arrow in  FIG.  37    attempts to pass through the magnetoelectric converter  25 , the component of the magnetic field along the z direction actively attempts to pass through the first shield  41  and the second shield  42  respectively. However, the component of the magnetic field in the x direction somewhat remains. Accordingly, the component of the magnetic field in the x direction attempts to permeate the magnetoelectric converter  25 . 
     On the other hand, the detecting directions of measured magnetic field of the magnetoelectric converter  25  are the z direction and the y direction. The magnetoelectric converter  25  does not detect the magnetic field in the x direction. Even when the above-described component of the magnetic field in the x direction permeates the magnetoelectric converter  25 , the degradation of detection accuracy of the measurement magnetic field, due to the permeation of the electromagnetic noise, is suppressed. 
     The alignment of the individual sensors  71  is not limited to the above-described example. For example, as shown in  FIG.  38   , a configuration where the individual sensors  71  are aligned in the x direction is conceivable. In this configuration, the first shields  41 , the second shields  42 , and the magnetoelectric converters  25 , of the individual sensors  71 , are aligned in the x direction. The magnetic-field detection directions of the magnetoelectric converter  25  of the individual sensor  71  are the x direction and the y direction. In this configuration, it may be configured such that the first shields  41  of the multiple individual sensors  71  aligned in the x direction are bundled together as one. Similarly, it may be configured such that the second shields  42  of the multiple individual sensors  71  are bundled together as one. 
       FIG.  38    also shows two individual sensors  71 . The measurement current flows through one of the two individual sensor  71  having the electrical-conduction bus bar  30  with an enclosed cross symbol.  FIG.  38    also indicates the magnetic field with an arrow. The magnetic field has components along the x direction and the z direction. Accordingly, the configuration has an environment where the external noise along the x direction and the z direction easily permeates the individual sensor  71 . 
     In this configuration, the magnetic permeability of the first shield  41  and the second shield  42  in the x direction is higher than that in the y direction. Accordingly, the component of the external noise along the x direction attempts to enter the first shield  41  and the second shield  42  respectively. On the other hand, the component of the external noise along the z direction does not depend on the anisotropy of the first shield  41  and the second shield  42  any longer. The component along the z direction attempts to permeate the magnetoelectric converter  25 . 
     For example, when the magnetic field indicated with a broken arrow in  FIG.  38    attempts to pass through the magnetoelectric converter  25 , the component of the magnetic field along the x direction actively attempts to pass through the first shield  41  and the second shield  42  respectively. However, the component of the magnetic field in the x direction somewhat remains. Accordingly, the component of the magnetic field in the z direction attempts to permeate the magnetoelectric converter  25 . 
     The detecting directions of the measurement magnetic field of the magnetoelectric converter  25  are the z direction and the y direction. The magnetoelectric converter  25  does not detect the magnetic field in the z direction. Even when the above-described component of the electromagnetic noise in the z direction permeates the magnetoelectric converter  25 , the degradation of detection accuracy of the measured magnetic field, due to the permeation of the electromagnetic noise, is suppressed. 
     The embodiments of the present disclosure have been explained hereinabove. The present disclosure is not limited to the above-described embodiments, but various changes can be made and implemented within the gist of the present disclosure. 
     (First Modification) 
     In the first embodiment, the example where the notches  41   c  are formed at the four corners of the first shield  41  has been shown. In this example, in the first opposite end part  41   e  of the first shield  41 , the length in the x direction is shorter than that of the first center part  41   d . The extending part  42   c  is formed in the second shield  42 . 
     As shown in  FIG.  39   , a configuration where the notches  41   c  are formed at the four corners of each of the first shield  41  and the second shield  42  may be employed. In the second opposite end part  42   e , the length in the x direction is shorter than that of the second center part  42   d . As shown in (b) of  FIG.  39   , the magnetoelectric converters  25  of the first sensing unit  21  and the second sensing unit  22  mounted on the wiring board  20  are positioned between the first center part  41   d  and the second center part  42   d . In  FIG.  39   , (a) shows a perspective view for explaining the arrangement of the shield, the magnetoelectric converter, and the electrical-conduction bus bar; and (b) is a side view for explaining the arrangement of the shield, the magnetoelectric converter, and the electrical-conduction bus bar. 
     Further, as shown in (a) of  FIG.  40   , it may be configured such that the extending part  42   c  and the notch  41   c  are not formed in the second shield  42 . As shown in (b) of  FIG.  40   , a configuration where the notches  41   c  are formed at two of the four corners of the first shield  41  may be employed. Note that in (b) of  FIG.  40   , two notches  41   c  are aligned in the x direction. In  FIG.  40   , (a) and (b) are perspective views for explaining the arrangement of the shield, the magnetoelectric converter, and the electrical-conduction bus bar. As shown above, the forming position of the notch  41   c  is not particularly limited as long as the length of the first both end part  41   e  of the first shield  41  in the x direction is shorter than that of the first center part  41   d.    
     (Second Modification) 
     In the first embodiment, the example where the integrated housing  73  has the bottom wall  77  and the peripheral wall  78 , and the multiple individual sensors  71  are accommodated in the storage space provided by the bottom wall  77  and the peripheral wall  78  of the integrated housing  73 , has been shown. However, as shown in  FIG.  41    to  FIG.  43   , it may be configured such that the integrated housing  73  does not have the peripheral wall  78 . In this case, the individual sensor  71 , rotated at 90°, is provided with respect to the bottom wall  77 . Thus, the front surface  30   a  and the rear surface  30   b  of the electrical-conduction bus bar  30  in the individual sensor  71  respectively face in the z direction. The one surface  41   a  and the rear surface  41   b  of the first shield  41  respectively face in the z direction. Similarly, the one surface  42   a  and the rear surface  42   b  of the second shield  42  respectively face in the z direction. The detection directions of the magnetoelectric converters  25  of the individual sensor  71  are the x direction and the y direction. 
     With this configuration, as shown in  FIG.  38   , the first shields  41  of the multiple individual sensors  71  are aligned in the x direction. The second shields  42  of the multiple individual sensors  71  are aligned in the x direction. The magnetoelectric converters  25  of the multiple individual sensors  71  are aligned in the x direction. 
     Note that in  FIG.  42   , (a) shows a top view of the second current sensor; (b) shows a front view of the second current sensor; and (c) shows a bottom view of the second current sensor. In  FIG.  43   , (a) shows a side view of the second current sensor; and (b) shows a front view of the second current sensor. (b) of  FIG.  42    and (b) of  FIG.  43    show the same figure. 
     In the present modification, bolt holes, the number of which is the same as the number of the individual sensors  71 , are formed along the z direction in the terminal block  80 . The bolt hole  30   c  is formed in the second exposed part  33  of the individual sensor  71 . The bolt is inserted through the bolt hole in the terminal block  80 , the bolt hole  30   c  in the second exposed part  33 , and the bolt hole formed in the wire terminal. Further, the nut is fastened to the end of the bolt. The nut is fastened to the bolt from the end of the bolt shaft toward the bolt head. The second exposed part  33  and the wire terminal are held between the bolt head and the terminal block  80 . With this configuration, the second exposed part  33  and the wire terminal are brought into contact, and electrically and mechanically connected to each other. 
     Third Embodiment 
     As shown in the first embodiment, the rib  52   a  is formed in the sensor housing  50  of the first current sensor  11 . Similarly, as shown in  FIG.  44   , the rib  52   a  may be formed in the sensor housing  50  of the individual sensor  71 . A guide part  72   a  for insertion of the individual sensor  71  into the wiring case  72  may be formed on the bottom wall  77  of the integrated housing  73 . The guide part  72   a  forms a groove having a hollow part in a similar shape to that of the rib  52   a . The guide part  72   a  is opened in the z direction. The rib  52   a  is passed via the opening into the hollow part of the guide part  72   a . With this configuration, the individual sensor  71  is easily assembled to the integrated housing  73  of the individual sensor  71 . Note that in the modification shown in  FIG.  44   , a groove  77   c  for providing the protruding end of the connection terminal  60  in the individual sensor  71  is formed in the bottom wall  77 . 
     (Fourth Modification) 
     As schematically shown in (a) of  FIG.  45   , in the respective embodiments, the example where the individual sensors  71  are provided on the U phase stator coil and the V phase stator coil of the motor has been shown. In the example, these individual sensors  71  have the first sensing unit  21  and the second sensing unit  22 . 
     However, as schematically shown in (b) of  FIG.  45   , a configuration where the individual sensors  71  are provided on the U phase stator coil, the V phase stator coil, and the W phase stator coil of the motor may be employed. These individual sensors  71  may only have the first sensing units  21 . 
     As described above, in the three phase stator coils, based on the currents which flow through the two stator coils, the remaining one current can be detected. Accordingly, based on outputs from two of the first sensing units  21  of the three individual sensors  71  provided on the three phase stator coils, the current which flows through the remaining one stator coil can be detected. Further, with the first sensing unit  21  of the individual sensor  71  provided on this remaining one stator coil, the current which flows through the remaining one stator coil can be detected. It is possible to determine whether or not an abnormality occurs in one of the two stator coils by comparing the two detected currents. 
     (Other Modifications) 
     In the respective embodiments, the example where the current sensor is applied to the in-vehicle system  100  which forms a hybrid system has been shown. However, the in-vehicle system to which the current sensor is applied is not limited to the above-described example. For example, the current sensor may be applied to the in-vehicle system of an electric vehicle or an engine vehicle. The system to which the current sensor is applied is not particularly limited. 
     While only the selected exemplary embodiments and examples have been chosen to illustrate the present disclosure, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made therein without departing from the scope of the disclosure as defined in the appended claims. Furthermore, the foregoing description of the exemplary embodiment and examples according to the present disclosure is provided for illustration only, and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.