Abstract:
A device for electrical energy supply and/or data supply of end devices using inductive coupling includes an oblong holding device and a number of adjacently arranged transmitting coils that generate magnetic field lines along the holding device. Structurally narrow end devices have flat receiving coils whose plane is oriented perpendicular to the longitudinal extension of the holding device.

Description:
FIELD OF THE INVENTION 
     The invention relates to a device for electrical energy supply and/or data supply of end devices using inductive coupling. 
     BACKGROUND OF THE INVENTION 
     The phenomenon of inductive coupling permits contactless energy transfer between a transmitting device and a receiving device and may be supplemented with primary coil and secondary coil to form a transformer. Examples of such systems are described in WO 98/15069 A1, EP 1 885 085 A1, DE 10 2007 060 811 A1, and DE 10 2007 061 610 B4. When the devices are coupled, a closed magnetic core is formed or only small air gaps in the core are permitted so that the contactless energy transmission is very efficient. However, this requires precise spatial positioning of primary coil relative to secondary coil, which sharply limits the freedom in spatial positioning for the primary transmitting device to the secondary transmitting device. 
     To be relieved of this limitation in spatial positioning, U.S. Pat. No. 7,262,700 B2 and US 2010/0328044 A1 suggest arranging on a desk surface of the transmitting device flat coils, as primary coils, that cooperate with secondary flat coils of the receiving device to supply the latter with power. The receiving device with the secondary coil is mobile and may be supplied with power at any position on the desk plate of the transmitting device, wherein the transmitting device scans for where the receiving device is located so that the primary coil is operated only there. The effective magnetic field lines between primary coil and secondary coil run perpendicular to the desk surface. 
     U.S. Pat. No. 6,803,744 B1 relates to an inductive energy transfer device for recharging the battery of cordless devices. Below the table surface, a table houses arrangements of primary coils that may be turned on via switches and that cooperate with secondary coils of the devices to be recharged. The devices to be recharged are a laptop computer and a cordless drill that obviously may be used for its intended purpose after recharging. 
     Known from EP 2 067 148 B1 is a transmitting device having a rail-like charging fixture for transferring electromagnetic energy to a plurality of electronic devices, and specifically a plurality of overlapping flat primary coils are provided along a rail of the transmitting device, which coils detect the presence of a receiving device by means of a sensor and selectively activate primary coils accordingly. The effective magnetic field lines between primary coil and secondary coil run perpendicular to the rail surface. 
     US 2003/0210106 A1 discloses a system of inductive coupling between a plate-like primary side of the transmitting device and a secondary side of the receiving device. The primary side has a flat winding in which the windings run in a helical or rectangular shape nested within one another to permit via a desk surface inductive coupling with the receiving device, whose position and orientation within an active area of the desk surface may be freely selected. The magnetic field lines run essentially parallel to the desk surface in this active area. The secondary side has a winding about a plate-like or cylindrical core. 
     Known from WO2010/125048 A1 is a system for supplying bus subscriber modules with contactless energy and data, which system includes within a hat-shaped carrier-rail a power supply rail that has an energy transfer interface and a data transfer interface and each of the bus subscriber modules has a corresponding energy transfer interface and a corresponding data transfer interface. The interfaces work based on spiral flat coils whose planes run parallel to one another so that the field lines extend vertical to the longitudinal extension of the carrier rail. 
     US 2002/0021226 A1 relates to an electrical apparatus having a monitoring device, support, and monitoring device for such an apparatus, and electrical installation incorporating them. A switchgear housing with support rails is provided for receiving electrical apparatus, each of which apparatus has a receiving coil. In a first configuration there are transmitting coils on the front sides of the switchgear housing in which two rails with attached apparatus extend, in a second configuration there is a transmitting coil parallel to two rails on which the electrical apparatus are arranged, and in a third configuration there are top hat rails, and a single flattened coil extends in the interior of each of these, thus supplying energy to a series of electrical apparatus placed on the top hat rails. It is not possible to allocate individual transmitting coils to individual receiving coils. 
     Electronic devices are often accommodated in switchgear cabinets and are frequently placed along retaining rails. Often a galvanic separation is required between the power supply and the user or end devices. Although such user or end devices are adapted to the retaining rail at their base, there are significant differences with respect to the longitudinal dimensioning of the rails. With narrow devices, the surface opposing the retaining rails is quite small so that inductive coupling between the power supply and the user or end device seems problematic. 
     SUMMARY OF THE INVENTION 
     The underlying object of the invention is to supply even narrow user or end devices lined up on a retaining device with electrical energy and/or with data in a contactless manner. 
     To this end the device for supplying electrical energy and/or data to end devices has an oblong holding device that permits end devices to be held lined up adjacent to one another. The holding device has a number of adjacently arranged transmitting coils whose dimension in the longitudinal direction of the holding device is matched to the dimension of the narrowest end device, seen in the longitudinal direction of the holding device. This dimension, called the width, is approximately the same as the width of structurally narrow end devices. Wider end devices may extend across the width of two or more transmitting coils. For generating magnetic field lines, the transmitting coils are embodied with a useable portion parallel to the longitudinal extension of the holding device and may be switched individually. 
     If power is to be supplied to the end devices in a contactless manner via the transmitting coils, they each have at least one receiving coil that detects the usable portion of the magnetic field lines extending parallel to the holding device and renders the end device usable. 
     The receiving coil of at least one end device spans a plane transverse to the usable portion of the field lines of the transmitting coils. Such a receiving coil may be characterized as a flat coil whose plane is perpendicular to the direction in which the holding device extends. Thus the receiving coil may be embodied extremely narrow and may be accommodated in each end device, even if the end device is exceptionally narrow. 
     It is also possible to accommodate two or more of the flat receiving coils in the end device, for instance because the electrical energy supply and the data supply are to be separated in the end device or because a plurality of galvanically separated equipment parts are to be supplied with energy. 
     With structurally narrow end devices, it is possible to appropriately act on associated individual transmitting coils and, with wider end devices, to interconnect individual transmitting coils to create transmitting coil groups in order attain a virtually longer coil. 
     Wider end devices must be provided with flat receiving coils, but do not have to be in order to detect the usable portion of the alternating magnetic field. 
     In order to generate magnetic field lines having an effective portion parallel to the longitudinal extension of the holding device, screw-like or helical windings may be provided for producing coils having a cylindrical cover and an associated coil axis parallel to the longitudinal extension of the holding device. The effective portion of the magnetic field lines runs outside of the coil cover on the side facing away from the holding devices. A similar course for the field results when the cylindrical coil cover is changed to a rectangular or elliptical structure. 
     The effective portion of the magnetic field lines, which runs parallel to the holding device, is detected by the at least one receiving coil, the windings of which run helically about an opening whose plane may be described by an axis that extends parallel to the longitudinal extension of the holding device. 
     For bundling the magnetic field lines, a coil core made of ferromagnetic or ferrimagnetic material may be employed that guides the field lines of the transmitting coil to the receiving coil. If positioning of the end device on the holding device is to be selected relatively freely and flexibly, an appropriately wide core gap is provided, or no coil cores are used at all so that the end devices may be positioned at any location along the holding device. However, coils with or without a coil core may be shielded against interfering metal bodies by means of ferromagnetic or ferrimagnetic materials. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An exemplary embodiment of the invention shall be described using the drawings. 
         FIG. 1  is a longitudinal section through an electrical energy supply device; 
         FIG. 2  is a perspective elevation of a detail; 
         FIG. 3  is a longitudinal section through coils in  FIG. 2 ; and, 
         FIG. 4  is a diagram of resonant inductive energy transfer. 
     
    
    
     DETAILED DESCRIPTION 
     The most important parts of the energy supply device are a holding device  1 , a layer  2  of adjacently arranged transmitting coils  20 , and a layer  3  of adjacently arranged end devices  31 ,  32 ,  33 ,  34 . The holding device  1  includes a rail  10  onto which the end devices  31  through  34  may be latched in a row, also with a gap  35  therebetween. The positioning of the end devices along the rail is free or flexible and does not require any particular sequence. 
     The transmitting coils  20  are embodied in a screw shape or are helical with a cylindrical cover and an axis that extends parallel to the longitudinal extension of the holding device  1 . Rectangular or elliptical screws may also be used. All such coil shapes are helical coils. In the exemplary embodiment depicted, six transmitting coils  20  are provided that may be turned on and off individually. Their power supply lines are attached to the holding device  1  or pass therethrough, but are not shown. When the transmitting coils  20  are used for data signal transfer, the corresponding data lines are also provided. When the transmitting coils  20  may be switched individually, this means that they may also be interconnected in groups, as is shown for the end device  32 . A discrete electronics unit may be allocated to each individual transmitting coil to be able to regulate parameters of power output per individual coil, including current phase, current amplitude, and current frequency. The electronics unit may also include a sensor that detects coupling effects with associated receiving coils to determine which end device is adjacent or whether an end device can even be activated via the specific transmitting coil (determines a gap in the row of end devices). 
     The transmitting coils are depicted without a core, but a non-closed core with an air gap could be present at the location at which one of the end devices is disposed. However, a ferrite structure  21  is usefully arranged to the side on the holding device  1  to prevent parasitic induction from the transmitting coils, which could interfere from sides of the holding device. In addition, eddy current losses are minimized in the possibly metal holding device. 
     At least some of the end devices house a flat coil  30  that works as a receiving coil with the closest transmitting coil  20 . The windings of the flat receiving coil  30  run in a helical shape, wherein “helical” shall also be understood to include wound in a rectangle, printed, or in some other configuration, as  FIG. 2  illustrates. The receiving coil  30  surrounds a central opening and defines a plane whose perpendicular plane runs parallel or nearly parallel to the longitudinal extension of the holding device  1 . The portion H 1  of the field lines that runs horizontal in  FIG. 1  therefore crosses the receiving coil  30  and induces a voltage or current flow that may be used for supplying electrical energy to the end device affected. Such a current flow may be interpreted as a data signal in the same manner. The reverse flow of information is also possible: The receiving coil  30  may also be switched as a transmitting coil to transfer data from the end device to the transmitting coils switched as receiving coils. In doing so, so-called “load modulation” may be used in which the receiving coil represents a varying load, which may be detected on the transmitting coil. 
     For the end device  32 , three individual transmitting coils  20  are interconnected by using joint activation to create a virtual larger coil in order to make a common magnetic field available for the end device  32 . This may be used for instance for higher current consumption or to supply devices whose width exceeds the fit of the narrower end devices  31 ,  33 . 
     The transmitting coil at the gap  35  is switched without current if no end device is disposed there. However, locations without a transmitting coil may also be provided, as for the end device  34 , which does not have any active connection to the system or represents a reserve site. The system is not active here. Feed voltage, for instance, or even data information may be passed further along the holding device via a bridge placed in the carrier rail. 
     The drawing in  FIG. 2  depicts how the device having primary coil P 1  and secondary coil  51  may be constructed for transferring energy inductively. The holding device  1  forms a top hat rail  10  to which the end devices may be clipped adjacent to one another in a row. The housings (not shown) for the end devices are embodied in a U shape at their attaching ends and engage around the transmitting coils  20  in order to keep the receiving coils  30  as close as possible to the associated transmitting coils  20 . To this end the housings have clips (not shown). The housings for the end devices each accommodate at least one receiving coil  30 . The ferrite structure  21  provided for shielding is arranged in the hollow space of the top hat rail  10 . Attached to the ferrite structure  21  is the transmitting coil  20  that generates magnetic field lines H 1 , H 2 , H 3 , H 4  ( FIG. 3 ). The magnetic field lines H 1 , which are parallel to the holding device, cause energy to be added to the receiving coil  30 . The energy is made available to an electronics unit  51  that may be attached to a circuit board  50 . 
     From the drawing in  FIG. 2  it may be clearly seen that the end devices may each clip to different locations along the rail  10  (which is depicted shortened for the purposes of the drawing). Thus the end devices may be positioned at any location along the rail  10 . 
     However, the ability of the receiving coil to be freely positioned has the drawback of weaker coupling between transmitting coil and receiving coil. Resonance effects between transmitting coil and receiving coil are used to attain better energy transfer. This is explained using  FIG. 4 . A transmitting coil  20  and two receiving coils  30   a ,  30   b  are arranged in an inductive coupling without using a magnetic core, which is indicated by a field line H 1 . 
     The transmitting coil  20  has a longer longitudinal extension than the receiving coils  30   a ,  30   b , which are embodied as flat coils, so that a plurality of these flat coils may be arranged along the elongate transmitting coil  20 . Power is supplied to the coil  20  via an alternating input voltage  22 . The receiving coils  30   a ,  30   b  are each disposed in a separate module, each with a load  41 ,  42  that receives the energy output by the coil  20 . Typically these loads each comprise a rectifier circuit, a smoothing capacitor, and an electronic circuit attached thereto. 
     The transfer of energy between the transmitting coil  20  and the receiving coils  30   a ,  30   b  is particularly efficient when the circuits including the respective coils are resonant at a suitable frequency of the input voltage. Each transmitting circuit with transmitting coil  20  and each receiving circuit with transmitting coil  30   a  or  30   b  has a resonance frequency that constitutes the inductances of the specific coils and the capacitances  43 ,  44 ,  45 . The capacitances also include capacitive coupling effects between the coil windings. To match the resonances to one another, each of the circuits may have discrete capacitors that are arranged in a series or parallel to the respective coils. Combinations of series and parallel circuits are also possible to match the resonances. With the alignment of the resonance frequency to the working frequency of the alternating input voltage  22 , the system may be operated at increased efficiency. In addition to the useful inductivity, which is indicated by the field line H 1 , there is stray inductance, symbolized by the field lines H 2 , H 3 , H 4 . The good efficiency may be explained in that the energy of the stray fields of the coils  20 ,  30   a ,  30   b  oscillates somewhat between the coil inductances and the capacitances  43 ,  44 ,  45  and is ideally not consumed. From the perspective of input voltage, the consumers  41  and  42  include almost only Ohmic portions. 
     To really be able to use the resonance effects, a regulating device (not shown) is allocated to each transmitting coil  20  and controls the current phase, current amplitude, and frequency of resonance with the coupled receiving coil  30 .