Abstract:
Apparatus are provided for receiving power from an external source. The apparatus includes a first electrical contact exposed to an exterior power source, a second electrical contact hardwired to an electrical bus, a separation device in physical contact with both the first electrical contact and the second electrical contact and conditionally insulating the first contact from the second contact and an electrical circuit configured to detect a voltage of the exterior power source and to physically modify the separation device to electrically connect the second contact to the exterior power source when a condition is met.

Description:
TECHNICAL FIELD 
     The technical field generally relates to vehicle electrical systems, and more particularly relates to an interface that protects an electrical system against an overvoltage during a jump start of the vehicle or during a reverse battery condition. 
     BACKGROUND 
     The amount of the electrical load on a vehicle is growing and is ever more complex. When all systems are in operation concurrently, a vehicle may consume upwards of 77 amps, which is sizable amperage. Not only is the amount of the electrical load growing but the sophistication of the load is also growing with more and more processors and other electronic features and equipment being added. Existing techniques for protecting electronic features from over voltages and reverse voltages, such as diodes and input resistors, may entail costs including excess power consumption and/or fuel usage. 
     Accordingly, it is desirable to protect vehicle electronics while reducing power consumption. In addition, it is desirable to eliminate the need for over and reverse voltage protection devices on each module and reduce power consumed in normal vehicle operation. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. 
     SUMMARY 
     A battery terminal is provided for receiving power from an external source. In one embodiment, the apparatus includes a first electrical contact exposed to an exterior power source, a second electrical contact hardwired to an electrical bus, a separation device in physical contact with both the first electrical contact and the second electrical contact and conditionally insulating the first contact from the second contact and an electrical circuit configured to detect a voltage of the exterior power source and to physically modify the separation device to electrically connect the second contact to the exterior power source when a condition is met. A relay or equivalent solid state device could also be used to electrically connect the second contact to the exterior power source. 
     A system is provided for receiving power from an external source. In one embodiment, the system includes an electrical bus of a vehicle, a vehicle battery, and a battery terminal. The battery terminal comprises a first electrical contact exposed to an exterior power source, a second electrical contact hardwired to the electrical bus of the vehicle, a separation device in contact with both the first electrical contact and the second electrical contact and conditionally insulating the first contact from the second contact, and an electrical circuit configured to detect a voltage of the exterior power source and to physically or electronically modify the separation device to electrically connect the first contact with the second contact when a condition is met. 
     A vehicle is provided for that receives power from an external source. In one embodiment the vehicle includes a vehicle body, a battery within the vehicle body; and a battery terminal. The battery terminal comprises a first electrical contact exposed to an exterior power source, a second electrical contact hardwired to an electrical bus, a separation device in contact with both the first electrical contact and the second electrical contact and conditionally insulating the first contact from the second contact, and an electrical circuit configured to detect a voltage of the exterior power source and to physically or electrically modify the separation device to electrically connect the first contact with the second contact when a condition is met. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The exemplary embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein: 
         FIG. 1  is a simplified vehicle in accordance with an embodiment; 
         FIG. 2  is a simplified diagram of a protection interface in accordance with an embodiment; 
         FIG. 3A  is a schematic of an electronic control circuit for a separation device in accordance with an embodiment; 
         FIG. 3B  is a schematic of a second electronic control circuit for a separation device in accordance with an embodiment; 
         FIG. 3C  is a schematic of a third electronic control circuit for a separation device in accordance with an embodiment; 
         FIG. 4  is a simplified schematic of an exemplary mechanical separation device and an exemplary control system in accordance with an embodiment; 
         FIG. 5  is a another simplified schematic of an exemplary mechanical separation device and an exemplary control system in accordance with an embodiment 
         FIGS. 6A and 6B  are a side view and a plan view of another exemplary mechanical separation device in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is merely exemplary in nature and is not intended to limit the application and uses. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. 
     Those of skill in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software executing on a processor, or combinations of both. Some of the embodiments and implementations are described above in terms of functional and/or logical block components (or modules) and various processing steps. However, it should be appreciated that such block components (or modules) may be realized by any number of hardware, software executing on a processor, and/or firmware components configured to perform the specified functions. 
     To clearly illustrate this interchangeability, various illustrative components, blocks, modules, circuits, and steps may be described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention. For example, an embodiment of a system or a component may employ various integrated circuit components, e.g., memory elements, digital signal processing elements, logic elements, look-up tables, or the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices. In addition, those skilled in the art will appreciate that embodiments described herein are merely exemplary implementations 
     The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. The word “exemplary” is used exclusively herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. 
     The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal 
     In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Numerical ordinals such as “first,” “second,” “third,” etc. simply denote different singles of a plurality and do not imply any order or sequence unless specifically defined by the claim language. The sequence of the text in any of the claims does not imply that process steps must be performed in a temporal or logical order according to such sequence unless it is specifically defined by the language of the claim. The process steps may be interchanged in any order without departing from the scope of the invention as long as such an interchange does not contradict the claim language and is not logically nonsensical. 
     Furthermore, depending on the context, words such as “connect” or “coupled to” used in describing a relationship between different elements do not imply that a direct physical connection must be made between these elements. For example, two elements may be connected to each other physically, electronically, logically, or in any other manner, through one or more additional elements. 
       FIG. 2  is a simplified diagram of an embodiment of a protection interface  5  disclosed herein that is used in conjunction with an electrical contact  2  of a jumper cable  3 . As a non-limiting example, the cable may be a traditional jumper cable  3  that include metal (e.g., copper) alligator clips  2  on each end of the cable  3 . However, other cable and contact designs that currently exist or that may be devised in the future can be readily adapted to be used herein without departing from the scope and spirit of this disclosure (See, e.g.,  FIG. 6A ). 
     In essence a faux electrical contact, also known herein as an “extra contact”  10 , is used to cover or electrically protect the actual contact that is directly connected (i.e., hardwired) to the vehicle electrical system  70  (See,  FIG. 1 ). The actual contact to the electrical system of the vehicle  5  is referred to herein and the “protected contact”  20 . If necessary, the protected contact  20  is further protected from contact with the alligator clip  2  by an insulating layer of material  30 . However, this insulating layer  30  may be optional depending on the construction and orientation of the protected contact  20 . 
     In the embodiment of a protection interface  5  illustrated in  FIG. 2 , the extra contact  10  and the protected contact  20  are separated by an electronically controlled separating device  40 . The separating device  40  is a self-contained mechanical or electronic switch such that when the voltage at the alligator clip  2  is sensed by the separating device  40  at extra contact  10  to be of the proper voltage level and polarity, the external power from the alligator clip  2  is electrically connected to the protected contact  20  by separating device  40  via the extra contact  10 . If the voltage is improper, the connection is not completed. The separating device  40  may have any suitable form factor and use method of operation as long as the form factor is physically constructed of a non-conducting structural material that is capable of electrically insulating the extra contact  10  from the protected contact  20 . 
     In other embodiments the separating device may be a semi-conducting silicon device. The silicon device insulates/separates the extra contact from the actual contact when not biased “on” and would conduct when properly biased. In some embodiments, the semi-conducting silicon device may be manifested as a 1000 amp switch. 
       FIG. 3A  presents an exemplary, non-limiting electronic switch  50  that may be used in the separating device  40  and is powered by the incoming voltage from the alligator clip  2  and/or from the protected contact  20 . The switch  50  comprises a relay or a solid state switch  58  that may be any suitable relay that may be known in the art or that may be developed in the future. The relay/switch  58  electrically connects the extra contact  10  to the protected contact  20 . 
     The switch/control circuit  50  comprises a diode  51 , a high limit Zener diode  54 , a low limit Zener diode  55  along with input resistors  52  and  53 , respectively. The control circuit also comprises a first transistor  56  and a second transistor  57 . 
     In operation, when the polarity of the voltage applied by the alligator clip  2  to the extra contact  10  is negative, or the voltage is below a predefined lower value the diode  51 , the base emitter junctions of transistors  56  and  57  are reversed biased such that there is no current through relay  58 . Hence, the separating device  40  does not allow a connection because transistor  57  is not biased to conduct. 
     When the voltage supplied from the alligator clip  2  is above the lower predefined value but below a upper predefined value, the low limit Zener diode breaks down into its conductive state allowing a base current to transistor to trigger the second transistor  57  thereby allowing current to flow through the relay  58  and shut the switch connecting the extra contact  10  to the protected contact  20 . 
     When the voltage supplied by the alligator clip  2  is higher than the predetermined upper limit, the high limit Zener diode breaks down causing a base current to be applied to the first transistor  56  thereby shorting the base of second transistor  57  to ground  26  and interrupting the current flow through the switch/relay  58 . Thus, protected contact  20  remains electrically isolated from the voltage at the alligator clip  2 . 
       FIG. 3B  is another exemplary embodiment of switch/control circuit  50  but includes transistor  63  and resistor  64 . The purpose of transistor  63  is to create a greater change in “On” current so that there will be a sharper turn on voltage point. 
       FIG. 3C  is yet another exemplary embodiment of switch/control circuit  50  but includes diode  62 . The purpose of diode  62  is to ensure there is enough power from the alligator clip  2  to engage the relay  58 . 
       FIG. 4  is a simplified system diagram of a non-limiting alternative embodiment of the protective interface  5  wherein the separation device  40  includes a mechanical device switch. As in the case of the embodiment of  FIG. 2 , the physical arrangement of the extra contact  10 , the separating device  40  and the insulator  30 , is configured such that is not possible for the alligator clip  2  to touch the protected contact  20 , but only the extra contact  10 . 
     When the extra contact  10  is touched by alligator clip  2 , the potential of the alligator clip  2  is sensed by Electronic Control Unit (ECU)  100 , via lead wire  60 . The ECU  100  is a non-limiting, exemplary control device and may comprise any suitable digital or analog circuitry known in the art or that may be developed in the future. 
     The ECU  100  is configured such that when the polarity and the amount of voltage is correct and within limits, the ECU  100  causes the actuator  200  to modify the separation device  40  to connect the extra contact  10  with the protected contact  20  to provide power to the vehicle. The term “modify” herein means a change in physical state from a conducting state to a non-conducting state or from a non-conducting state to a conducting state. 
     The electronic control unit  100  may receive its power from the alligator clip  2  via the extra contact  10  when the alligator clip contacts the extra contact  10 . Or, the electronic control unit  100  may receive its power from the vehicle battery  25 . The ECU  100  has a ground  26 . 
     In an equivalent embodiments of the protective interface  5 , the interface may include a sensing resistor  27  arranged to sense the potential difference between the extra contact and the protected contact. The inclusion of a sensing resistor  27  is an optional feature. 
     An advantage of the sensing resistor  27  is that it allows the safe parallel connection of the batteries  25  of two vehicles equipped with the protection interface  5 . For example, a driver may activate a circuit or a resistive switch  61  (e.g., a circuit breaker) in the protective interface  5  of the vehicle with a good battery  25 . The resistive switch circuit  61  connects power from the protected contact  20  to the extra contact  10  to provide power to the extra contact and thus to the dead battery. The sensing resistor  27  monitors against an excessive current condition and will open resistive switch circuit  61  in such a case. With this power connection, the protective interface  5  of the bad battery would connect its extra contact  10  to its protected contact  20  in the normal manner as described above. The protective interface  5  of the good battery would then connect its extra contact  10  to its protected contact  20  in the normal manner as described above. 
       FIG. 5  is another equivalent embodiment of the protective interface  5 . Wherein like numbers reflect like components of  FIG. 4 . In the alternative embodiment of  FIG. 5 , resistor  27  is in series with switch  61 . 
     In the vehicle  400  (See  FIG. 1 ) with a good battery  25  (See  FIG. 1 ) the switch  61  is closed (manually or automatically) and applies voltage to the extra contact via resistor  27 . This same vehicle monitors the voltage drop across this resistor  27  via the ECU  100  and opens switch  61  if the resulting current is excessive as would recognized by those of ordinary sill in the art. The closing of switch  61  applies voltage thru the resistor  27  so that second vehicle with the bad battery can assess the voltage of the good battery  25  and will close its electronically controlled separating device  40  in the manner discussed above. The detection circuit on the vehicle  400  with the good battery has been disabled during this sequence until the voltage across resistor  27  has been verified and sufficient time has elapsed to ensure the vehicle with the bad battery has had enough time to close its electronically controlled separating device  40 . Non-limiting examples of switch  61  could be a resettable switch or a nonlinear resistor that could increase its resistance in response to excessive current. 
       FIGS. 6A and 6B  are simplified side and plan view, respectively, of an exemplary, non-limiting mechanical separation device  300 . These particular drawings assume that the jumper cable  3  has a pin or a rod  2 ′ in place of the traditional alligator clip  2 . However, the geometry of the separation device  300  can be a substantially parallelepiped shape instead of a cylinder such that the alligator clip  2  can be inserted while in a shut position in the same fashion as the depicted rod  2 ′. 
     The mechanical separation device  300  includes a hollow casing  310  with at least one open end  312 , a protected contact  320 , an extra contact  330 , an ECU  100 , a plunger  340  (or other physical barrier element) penetrating the wall of the hollow casing and protruding into the interior space  311  of the hollow casing, and a solenoid  350 . The ECU  100  controls solenoid  350  and thereby the position of the plunger  340  placing it into either a powered retracted state or in a normally unpowered extended state. 
     In the normally unpowered state, where no jumper cable rod is present, the plunger  340  is in its normally extended position. In this position, rod  2 ′ cannot pass into the hollow casing far enough to contact the protected contact  320  due the interference of the extended plunger  340 . However, rod  2 ′ can penetrate far enough to contact the extra contact  330 . Once the rod  2 ′ contacts the extra contact  330 , the voltage polarity and amount is sensed at the extra contact by ECU  100  via lead  60 . When the voltage delivered by the rod is a positive polarity and is between a predetermined maximum and a predetermined minimum, the ECU  100  energizes the solenoid  350  which withdraws plunger  340  from the interior space  311  to allow the rod  2 ′ to penetrate further and contact the protected contact, thereby delivering power to the vehicle via power take off  70 . 
     While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the disclosure as set forth in the appended claims and the legal equivalents thereof.