Power Distributor, and On-Board Electrical System Having at Least One Power Distributor

Abstract

A power distributor, in particular for an on-board network of a motor vehicle, has an intermediate tap, two power outputs, and one each switching unit for each power output. A switch is provided for a need-based blocking of the associated power output. Each of the switching units is designed in such a way that a blocking of the associated power output takes place, if, in the event a voltage drop at the associated power output and/or at the intermediate tap below a first setpoint value, an error case is determined. The greater the corresponding voltage drop, the faster the blocking of the associated power output takes place.

Claims

1-25. (canceled)

26. A power distributor, comprising: two power outputs and an intermediate tap; two switching units being a respective switching unit for each of said power outputs, said switching unit having a switch for blocking an associated power output if required; each of said switching units being configured such that a blocking of the associated said power output is effected if, in the event of a voltage drop at the associated said power output and/or at said intermediate tap to below a first setpoint value, a fault situation is ascertained, and wherein, the greater the voltage drop, the more rapidly the blocking of the associated said power output is effected.

27. The power distributor according to claim 26, wherein, in the event of a fault situation, the power output respectively connected most directly to the power source is blocked, or only the power output respectively connected most directly to the power source is blocked.

28. The power distributor according to claim 26, wherein said intermediate tap is a distributor node or a supply output for supplying a plurality of electrical loads.

29. The power distributor according to claim 26, wherein each of said switching units has a current-direction monitoring unit.

30. The power distributor according to claim 29, wherein each of said switching units has a current-direction monitoring unit with a comparator circuit, and said comparator circuit is configured, for the purpose of determining the current direction, to compare the voltages before and after the associated switch, or before and after an auxiliary resistor at the corresponding said power output, with each other.

31. The power distributor according to claim 26, wherein each of said switching units is linked to a voltage monitoring unit for monitoring the voltages at said power outputs and/or the voltage at said intermediate tap, or each of said switching units has a voltage monitoring unit for monitoring the voltage at the associated said power output and/or at said intermediate tap is monitored.

32. The power distributor according to claim 31, wherein each voltage monitoring unit has a comparator circuit for comparing the voltage at the associated said power output and/or at said intermediate tap with a reference voltage, the reference voltage corresponding to the first setpoint value.

33. The power distributor according to claim 31, further comprising a delay element connected in series before each said voltage monitoring unit, such that a voltage drop at the associated said power output and/or at said intermediate tap causes a voltage drop having an altered time characteristic at the respective said voltage monitoring unit.

34. The power distributor according to claim 26, wherein each of said switching units has a current-direction monitoring unit, having a comparator circuit with an output linked to an output of a voltage monitoring unit having a comparator circuit for a joint evaluation of the associated output signals.

35. The power distributor according to claim 34, wherein said outputs of said two comparator circuits of each switching unit are linked to each other via a logic gate.

36. The power distributor according to claim 35, wherein said outputs of said two comparator circuits of each switching unit are linked to each other via an AND gate and an OR gate connected in series after said AND gate.

37. The power distributor according to claim 36, wherein each of said switching units has a set memory configured to permanently maintain an initiated blocking.

38. The power distributor according to claim 37, wherein said set memory is connected to an output of said OR gate and additionally to an input of said OR gate.

39. The power distributor according to claim 26, wherein a lock function is realized, by means of which a reaction capability of another switching unit or of all other switching units is blocked temporarily, as soon as a switching unit has reacted because of a fault situation.

40. The power distributor according to claim 26, wherein each of said switching units is configured to effect the blocking of the associated said power output without communication with other switching units.

41. The power distributor according to claim 26, wherein said two switching units are spatially separate from each other and said intermediate tap is a conductor connection, which connects said two switching units to each other in an electrically conducting manner.

42. The power distributor according to claim 41, wherein at least one of said two switching units is arranged in a fusebox, together with a distributer busbar and/or a number of melting fuses and/or a number of electronic fuses.

43. An on-board electrical system for a motor vehicle, comprising at least one power distributor according to claim 26.

44. The on-board electrical system according to claim 43, comprising a plurality of power distributors each according to claim 26 and wherein a number of electrical loads are connected to each power distributor via the intermediate tap thereof, wherein said power distributors are interconnected via their power outputs and intermediate connecting conductors, and wherein two electrical energy sources are connected at two power outputs or at two intermediate taps, or at one power output and at one intermediate tap of two power distributors, for the purpose of redundant supply of electric power to the electrical loads, such that, in the event of a short circuit along one of the connecting conductors, the latter is electrically isolated by the connected power distributors.

45. The on-board electrical system according to claim 44, wherein said power distributors are connected in a distributor chain, respectively connected at the ends of which, via a supply output or a power output, is one of the electrical energy sources.

46. The on-board electrical system according to claim 44, wherein said power distributors are connected in a power ring, wherein an electrical energy source is in each case connected to two power distributors via a supply output or a power output.

47. The on-board electrical system according to claim 43, comprising a number of safety-relevant electrical loads, which are used to realize a safety-relevant function, and a number of other electrical loads, as well as a first on-board electrical sub-system and a second on-board electrical sub-system, wherein the first and the second on-board electrical sub-system are connected to each other via the power distributor, wherein, for the purpose of redundant supply, the safety-relevant electrical loads are each integrated into both on-board electrical sub- systems, and wherein, for the purpose of single supply, the other electrical loads are each integrated into one of the two on-board electrical sub-systems.

48. The on-board electrical system according to claim 47, wherein all other electrical loads are integrated into the first on-board electrical sub-system.

49. The on-board electrical system according to claim 43, comprising: a number of safety-relevant electrical loads, which are used to realize a safety-relevant function, and a number of other electrical loads, as well as a first on-board electrical sub-system and a second on-board electrical sub-system, wherein the first and the second on-board electrical sub-system are connected to each other via the power distributor, wherein, for the purpose of redundant supply, the safety-relevant electrical loads are each integrated into both on-board electrical sub-systems, and wherein, for the purpose of single supply, the other electrical loads are connected to the intermediate tap.

50. The on-board electrical system according to claim 49, wherein the other electrical loads are connected to the intermediate tap via an additional switching unit or via an additional power distributor according to claim 26.

Description

[0052] Exemplary embodiments of the invention are explained in greater detail in the following on the basis of a schematic drawing. Therein:

[0053] FIG. 1 shows a block diagram of a first embodiment of a power distributor, having a first embodiment of a control unit,

[0054] FIG. 2 shows a block diagram of a second embodiment of a power distributor, having a second embodiment of the control unit,

[0055] FIG. 3 shows a block diagram of a first embodiment of an on-board electrical system, having a plurality of power distributors,

[0056] FIG. 4 shows a block diagram of a second embodiment of the on-board electrical system, having a plurality of power distributors,

[0057] FIG. 5 shows a block diagram of a third embodiment of the on-board electrical system, having a power distributor,

[0058] FIG. 6 shows a block diagram of a fourth embodiment of the on-board electrical system, having a power distributor,

[0059] FIG. 7 shows a block diagram of a fifth embodiment of the on-board electrical system, having a power distributor,

[0060] FIG. 8 shows a block diagram of a sixth embodiment of the on-board electrical system, having a power distributor,

[0061] FIG. 9 shows a block diagram of a third embodiment of the control unit,

[0062] FIG. 10 shows a block diagram of a fourth embodiment of the control unit, and

[0063] FIG. 11 shows a block diagram of a fifth embodiment of the control unit.

[0064] In all figures, parts that correspond to each other are in each case denoted by the same references.

[0065] A power distributor 2, described exemplarily in the following and shown in outline in FIG. 1, serves preferably to realize a so-called supply node in an on-board electrical system 4, represented exemplarily in FIG. 3 to FIG. 6, of a motor vehicle 6.

[0066] In the exemplary embodiment according to FIG. 1, that power distributor 2 in this case is realized at least partly on a printed circuit board 8 enclosed in a plastic housing, which is not included in the depiction. It has two power outputs 10, which are realized as power connections, such that, depending on the operating situation or operating state of the power distributor 2, electric power/current flows into the power distributor 2, or alternatively electric power/current flows out of the power distributor 2, via a corresponding power output 10. When the power distributor 2 is in the installed state, the corresponding power outputs 10 are then connected directly, or indirectly via line segments 12, to further power distributors 2, to other electrical assemblies and/or to electrical energy sources, for example a battery 14, such that the power distributor 2 realizes, in particular, a supply node in the on-board electrical system 4 of the motor vehicle 6.

[0067] Further, the power distributor 2 has an intermediate tap 16, which in the exemplary embodiment according to FIG. 1 is realized as a supply output 16, which is connected in series between the two power outputs 10 and via which a number of electrical loads 18 can be supplied with electrical energy when the power distributor 2 is in operation. For this purpose the supply output 16 in the exemplary embodiment according to FIG. 1 is realized as a distributor plate 20 having a plurality of connection arms 22, a melting fuse 24 being integrated into each connection arm 22, according to a principle known per se. In the exemplary embodiment, connected in turn to each connection arm 22 is a plug-in connector 26, at which an electrical load 18 can be connected via a plug-in connection. According to an alternative embodiment, the connection arms 22 jointly realize the plug-in contacts of a single plug-in connector 26.

[0068] The power distributor 2 additionally has a switching unit 28, having a switch 30 for each power output 10, which enables the associated power output 10 to be blocked if necessary.

[0069] In the exemplary embodiment according to FIG. 1, a corresponding switch 30 in this case is realized by three semiconductor switches 32 connected in parallel, a blocking diode 34 being connected in parallel to each semiconductor switch 32. The semiconductor switches 32 in this case are of substantially identical design, and configured for rapid switching operations. Preferably in this case, semiconductor switches 32 are used that can be blocked with a few s, thus in 10 to 100 s.

[0070] Provided in this case, in particular for applications having a relatively large power requirement, are switches 30 having a plurality of semiconductor switches 32 connected in parallel, to which the corresponding power is distributed. In the case of a lesser power requirement, and/or in cases in which the requirements for the switching speed are lower, a corresponding switch 30 may possibly be realized by means of only one semiconductor switch 32, and in such cases the use of a plurality of semiconductor switches 32 is also dispensed with. A corresponding exemplary embodiment, in which each switch 30 is realized by a single semiconductor switch 32, having a blocking diode 34 connected in parallel, is represented in FIG. 2.

[0071] Also part of each switching unit 28 is a control unit 36, by means of which the switch 30 of the corresponding switching unit 28 is driven, and by means of which it is determined whether the associated switch 30, and thus the associated power output 10, is blocked or unblocked. In the exemplary embodiment, in this case the control units 36 of the power distributor 2, on the one hand, and the switches 30 of the power distributor 2, on the other hand, are realized on different sides of the printed circuit board 8 and interconnected via through-platings. According to an alternative variant, the control units 36, on the one hand, and the switches 30, on the other hand, are realized on different printed circuit boards 8, which are then interconnected, for example, via lines, or alternatively the switching units 28 of the power distributor 2 are realized as a whole on one side of a printed circuit board 8.

[0072] In addition, in the exemplary embodiment the switching units 28 are realized in such a manner that, in an initial state, the semiconductor switches 32 of the switches 30 are blocked, without a supply voltage supplied from the outside or made available to the power distributor 2, and accordingly have to be unblocked for operation or normal operation of the power distributor 2 in the on-board electrical system 4. Used for this purpose is the voltage that is available, via the power outputs 10, in normal operation, from which voltage there is generated, by means of an internal voltage supply circuit 38 having a voltage pump 40, a supply voltage for the switching units 28, and in particular for the switches 30, that simultaneously unblocks the semiconductor switches 32 of the switches 30. The supply voltage of the semiconductor switches 32 of the switches 30 via the voltage supply circuit 38 in this case is typically maintained permanently, and accordingly the semiconductor switches 32 are normally unblocked as soon as a corresponding power distributor 2 is first installed in the motor vehicle 6 and connected to an electrical energy source, for example a battery 14. In some cases the corresponding internal voltage supply circuit 38 also has an undervoltage protection 42, which only releases the supply voltage for the switching units 28, and in particular for the switches 30, when the supply voltage is sufficient to fully switch-through all semiconductor switches 32.

[0073] When the semiconductor switches 32, and thus the switches 30, are unblocked, monitoring of the associated power outputs 10 is effected by the switching units 28 and, in the event of a fault situation being ascertained at a power output 10 by the switching unit 28, the corresponding power output 10 is blocked, in that the associated switch 30 is driven and thereby blocked. In the blocked state, current is prevented from flowing, via the corresponding power output 10, out of the power distributor 2.

[0074] The fault situation in this case exists at a power output 10 if power/current flows out of the power distributor 2 via this power output 10 while the voltage at the corresponding power output 10 is below a specified first setpoint value.

[0075] Accordingly, the voltages and current directions at the power outputs 10 are monitored by the switching units 28.

[0076] In the exemplary embodiment according to FIG. 2, the monitoring of the voltages at the power outputs 10 in this case is effected indirectly, by monitoring of the voltage at the intermediate tap 16, or at the supply output 16, it being assumed that the voltage at the voltage tap 16, or at the supply output 16, is comparable with the voltages at the power outputs 10 when the semiconductor switches 32 are closed. According to an alternative design, on the other hand, direct monitoring of the voltages is effected directly at the corresponding power outputs 10.

[0077] A corresponding voltage monitoring is effected in this case by a voltage monitoring unit 44, by means of which voltage drops at the intermediate tap 16, or at the corresponding supply output 16, can be detected. If, during operation of the power distributor 2, starting from a supply voltage or nominal voltage of, for example, approximately 12 volts, the monitored voltage falls below a specified first setpoint value of, for example, 9 volts, the first condition for the fault situation is thereby ascertained by the switching unit 28.

[0078] In this case, in the specification of the first setpoint value it is taken into account that the voltage in an on-board electrical system 4 typically varies locally and/or is subject to fluctuations over time. However, these variations are considered to be unproblematic, and accordingly should not result in ascertainment of the fault situation. At the same time, however, it is desirable that the power distributor 2, or rather the switching units 28, react as rapidly as possible to malfunctions in the on-board electrical system, specifically even when a malfunction, thus for example the occurrence of a defect in the component in the on-board electrical system 4, does not result in a complete collapse of the supply voltage in the on-board electrical system 4, thus in the voltage at a power output 10 dropping to a value in the range of a frame potential. A first setpoint value that is approximately 20% below the so-called nominal voltage is an advantageous compromise in this case.

[0079] Further, in the exemplary embodiment, the switching units 28, in addition to monitoring the voltage, monitor the current direction at the associated power output 10, by means of a current-direction monitoring unit 45. In this case, the current direction is ascertained indirectly, via a voltage difference, for which purpose, in turn, a comparator circuit is used, by which the potentials before and after the associated switch 30 are compared with each other. The second condition is then fulfilled when current flows out of the power distributor 2 via the associated power output 10.

[0080] In the exemplary embodiment, the fault situation only exists, however, if both conditions are fulfilled, thus if one switching unit 28 ascertains that current is flowing out of the power distributor 2, via the associated power output 10, while the voltage at the associated power output 10 is below the first setpoint value. Therefore, as represented in the exemplary embodiment according to FIG. 2, the two comparator circuits of each switching unit 28 are linked to each other on the output side via a simple logic means, i.e. here an AND gate 46.

[0081] The associated switch 30 in this case is blocked in that a semiconductor switch 48 connected in series after the AND gate 46 is unblocked, and as a result the potential at the gate of the semiconductor switch 32 of the switch 30 is pulled to a frame potential or a source potential. Once unblocked, the semiconductor switch 48 connected in series after the AND gate 46 is kept permanently unblocked by means of a set memory 50, as a result of which, ultimately, the associated switch 30 remains permanently blocked. For this purpose, connected in series after the AND gate is an OR gate 52 that, both on the input side and on the output side, is connected to the set memory 50. In the exemplary embodiment, a resetting of the set memory 50, which is realized, for example, as a capacitor, and consequently a blocking of the series-connected semiconductor switch 48 and ultimately an unblocking of the associated switch 30, is only possible in that the set memory 50, together with the associated input at the OR gate 52, is pulled, via a reset contact 54, to a frame potential or a source potential.

[0082] In addition to the reset contact 54, the power distributor 2 or each switching unit 28, depending on the embodiment variant, has further driving and test contacts or contact connections, which allow various signals to be fed in and/or read out in order, for example, to ascertain the sate of the power distributor, or of the respective switching unit 28, thus in particular whether or not there is a defect present in the power distributor 2, or in the respective switching unit 28. For this purpose, for example as part of a servicing of the motor vehicle, a test device is then connected, via the contacts, or contact connections, to the power distributor 2, or to the respective switching unit 28. The resetting of the set memory 50 is typically effected as part of a servicing of the motor vehicle 6, specifically after the malfunction that resulted in the setting of the set memory 50, and thus in the blocking of the associated switch 30, has been eliminated.

[0083] Further, preferably connected in series before each voltage monitoring unit 44 is a delay element that is designed, for example, as an RC element 56. A voltage drop at the input of the voltage monitoring unit 44, thus, in the exemplary embodiment, at the input of the corresponding comparator circuit, is thereby additionally delayed with respect to a voltage drop occurring at the associated power output 10, or at the intermediate tap, or at the supply output 16, wherein, the less or the more slowly the voltage drops at the power output 10, or at the supply output 16, the greater is the delay.

[0084] With such a power distributor 2, it is then also possible to realize an advantageous, redundant on-board electrical system 2 in which, according to an embodiment variant, a plurality of power distributors 2, for example in the form of a ring, and represented in FIG. 3, or in the form of a strand, and represented in FIG. 4, are arranged, and are connected to two independent electrical energy sources, i.e. in particular two batteries 14.

[0085] If, for example, a short circuit, or other defect causing a significant voltage drop, then occurs in one of the line segments 12, then in each case only those switches that are closest to the defect along the current paths, i.e. that are positioned closest to the fault source, are blocked, as a result of which the corresponding line segment 12 is isolated. Following a corresponding isolation of a line segment 12, however, all power distributors 2 continue to be connected to at least one battery 14, such that the supply to the electrical loads 18 connected to the power distributors 2 is still ensured.

[0086] According to an alternative embodiment variant, the on-board electrical system 4 is realized with only one such previously described power distributor 2, the on-board electrical system 4 in this case preferably being constructed, as it were, in two parts, and accordingly having a first on-board electrical sub-system 58 and a second on-board electrical sub-system 60. An exemplary embodiment for this is depicted schematically in FIG. 5, wherein the second on-board electrical sub-system 60 is represented by a broken line.

[0087] The first on-board electrical sub-system 58 in this case serves to supply a number of safety-relevant electrical loads 62 and a number of other electrical loads 64, whereas the second on-board electrical sub-system 60 is realized exclusively to supply the safety-relevant electrical loads 62, such that the latter are additionally protected by a second supply possibility. This means that a redundant supply is provided only for the safety-relevant electrical loads 62.

[0088] The two on-board electrical sub-systems 58, 60 in this case are connected or linked to each other via the one power distributor 2, and accordingly in the fault situation, thus in the event of a previously described fault, the two on-board electrical sub-systems 58, 60 are separate from each other, with the result that only one of the two on-board electrical sub-systems 58, 60 fails and the supply to the safety-relevant electrical loads 62 continues to be ensured by the respective other on-board electrical sub-system 58, 60.

[0089] In a modified variant of the on-board electrical system 4 according to FIG. 5, both on-board electrical sub-systems 58, 60 are used to supply other electrical loads 64, but in this case also the other electrical loads 64 are preferably each connected to only one of the two on-board electrical sub-systems 58, 60, such that the corresponding other electrical loads 64 fail if the associated on-board electrical sub-system 58, 60 fails.

[0090] A modification of the on-board electrical system 4 according to FIG. 5 is represented in FIG. 6, wherein, in this case, the two switching units 28 of the power distributor 2 are spatially separate from each other and arranged in separate housings. In this case, each of the two switching units 28 is preferably part of a so-called fusebox 66, in which a so-called distributor busbar 68 is arranged, as well as, typically, a number of fuse elements, for example melting fuses and/or electronic fuses. In the case of this embodiment variant, the power distributor 2 is, as it were, halved, and each of the two housing, or each fusebox has, as it were, half of a power distributor 2.

[0091] The two fuseboxes 66, with the switching units 28 contained therein, are furthermore expediently connected to each other in an electrically conducting manner via the intermediate tap 16 of the power distributor 2 for exchange of power or transmission of power, in which case the intermediate tap 16 is designed, for example, as a conductor connection or cable connection. One of the two fuseboxes 66 in this case is arranged in the front region of the moor vehicle 6, and the other of the two fuseboxes 66 is then arranged, for example, in the rear region of the motor vehicle 6.

[0092] Moreover, in the case of this embodiment, each switching unit 28 preferably has its own internal voltage supply circuit 38.

[0093] Shown in FIG. 7 is a further variant of the on-board electrical system 4, which is similar in structure to the embodiment variant according to FIG. 6. Here, however, other electrical loads 64 are in each case integrated into both on-board electrical sub-systems 58, 60, and in addition another electrical load 64 is connected to the intermediate tap 16 for the purpose of supply.

[0094] As an alternative to the redundant supplying of the safety-relevant electrical loads 62, a redundancy can be achieved in that the safety-relevant electrical loads 62 are installed twice, specifically in such a manner that each safety-relevant electrical load 62 is present once in the first on-board electrical sub-system 58 and once in the second on-board electrical sub-system 60. Such an on-board electrical system embodiment is indicated in FIG. 8. In addition, in the case of this embodiment variant, all other electrical loads 64 are connected to the intermediate tap 16. This connection in this case is designed as an indirect connection, an additional fusebox 66, having an additional switching unit 28, being connected in series between the intermediate tap 16 and the other electrical loads 64. In this case, the power distributor 2 then has, as it were, three switching units 28.

[0095] Finally, in the representations FIG. 9 and FIG. 10, two alternative embodiments of the control unit 36 are depicted. In the case of these embodiments, the logic circuit is constructed, not from AND gates 46 and OR gates 52, but by means of NAND gates 72 and NOR gates 74.

[0096] Furthermore, in the case of these embodiments of the control unit 36, a so-called lock function is realized, which makes it possible to block the reaction capability of a switching unit 28 having such a control unit 36, at least temporarily, thus for example for a period of approximately 100 to approximately 300 s. For this purpose, a switching signal or control signal is then supplied to the logic circuit of the control unit 36 of the switching unit 28, for example via a lock input 70, in such a manner that, at least temporarily, irrespective of the voltage monitored by means of the voltage monitoring unit 44, the semiconductor switch 48 can no longer be unblocked, and accordingly the associated switch 30 of the switching unit 28 cannot be blocked.

[0097] Typically in this case, the reaction capability of a switching unit 28 is to be blocked if, and only if, a further switching unit 28 of the same power distributor 2 has reacted or is just then reacting because of a fault situation. Therefore, in the exemplary embodiment according to FIG. 11, the logic circuits of two control units 36 of two switching units 28 of a power distributor 2 are linked to each other to realize such a lock function. In this case, the logic circuits of the two control units 36 are designed, apart from the link, such that they correspond to the logic circuit of the control unit 36 according to FIG. 9. To realize the link, in the case of both control units 36 the output of the NOR gate 74 that drives the associated semiconductor switch 48 of the respective control unit 36 is in each case connected, via an RC element 76, to an input of the NAND gate 72 of the respectively other control unit 36 that is connected in series after the associated voltage monitoring unit 44. As a consequence, a switching signal or control signal that, in one of the control units 36 of the power distributor 2, unblocks the associated semiconductor switch 48, then, as it were, simultaneously blocks an unblocking of the semiconductor switch 48 of the other control unit 36 of the power distributor 2.

[0098] The invention is not limited to the exemplary embodiment described above. Rather, other variants of the invention may also be derived by persons skilled in the art, without departure from the provisions of the invention. Moreover, in particular, all individual features described in connection with the exemplary embodiment can also be combined with each other in any manner, without departure from the provisions of the invention.

LIST OF REFERENCES

[0099] 2 power distributor

[0100] 4 on-board electrical system

[0101] 6 motor vehicle

[0102] 8 printed circuit board

[0103] 10 power output

[0104] 12 line segment

[0105] 14 battery

[0106] 16 intermediate tap/supply output

[0107] 18 electrical load

[0108] 20 distributor plate

[0109] 22 connection arm

[0110] 24 melting fuse

[0111] 26 plug-in connector

[0112] 28 switching unit

[0113] 30 switch

[0114] 32 semiconductor switch

[0115] 34 blocking diode

[0116] 36 control unit

[0117] 38 internal voltage supply circuit

[0118] 40 voltage pump

[0119] 42 undervoltage protection

[0120] 44 voltage monitoring unit

[0121] 45 current-direction monitoring unit

[0122] 46 AND gate

[0123] 48 semiconductor switch

[0124] 50 set memory

[0125] 52 OR gate

[0126] 54 reset contact

[0127] 56 RC element

[0128] 58 first on-board electrical sub-system

[0129] 60 second on-board electrical sub-system

[0130] 62 safety-relevant electrical load

[0131] 64 other electrical load

[0132] 66 fusebox

[0133] 68 distributor busbar

[0134] 70 lock input

[0135] 72 NAND gate

[0136] 74 NOR gate

[0137] 76 RC element