Power supply circuit

Abstract

Provided is a power supply circuit capable of reducing the cost of a power supply system without providing another circuit for directly connecting a main power supply to an in-vehicle load. A power supply circuit for supplying power to an in-vehicle load, the power supply circuit being provided with: a through circuit that is inserted between a main power source and the in-vehicle load and that controls the supply of power from the main power source to the in-vehicle load; and a redundant circuit that controls the supply of power from the auxiliary power source to the on-board load when the main power source fails, and the through circuit supplies the power of the main power source to the on-board load even when the ignition state of the vehicle is OFF when the main power source does not fail.

Description

Technical Field

[0001] This invention relates to a power supply circuit for supplying power to onboard loads mounted in a vehicle. Background Technology

[0002] Patent document 1 discloses a power supply system that, in the event of a failure of the main power supply that supplies power to multiple vehicle-mounted loads (gear shifter, braking device, door unlocking device) mounted on a vehicle, can replace the main power supply by supplying backup power to the multiple vehicle-mounted loads from an auxiliary power supply.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2022-161163 Summary of the Invention

[0004] In the power supply system described in Patent Document 1, for vehicle-mounted loads (such as door unlocking devices) requiring auxiliary power, in addition to a circuit (path) connected to the main power supply via a redundant power supply including the auxiliary power supply, there is another circuit (path) directly connected to the main power supply so that power can be supplied even when the redundant power supply is not working. However, in this circuit structure, two circuits are required to supply power from the main power supply to the vehicle-mounted load, which increases the cost of the power supply system.

[0005] The present invention was made in view of the above-mentioned problems, and its object is to provide a power supply circuit that can reduce the cost of the power system without setting up another circuit that directly connects the main power supply to the vehicle load.

[0006] To address the aforementioned issues, one aspect of the present invention is a power supply circuit that supplies power to an on-board load. The power supply circuit includes: a direct-connect circuit inserted between the main power supply and the on-board load, controlling the power supply from the main power supply to the on-board load; and a redundant circuit that, in the event of a main power supply failure, controls the power supply from an auxiliary power supply to the on-board load. The direct-connect circuit, even when the vehicle's ignition is off, supplies power from the main power supply to the on-board load when the main power supply is not faulty.

[0007] Invention Effects

[0008] According to the power supply circuit of the present invention described above, even when the vehicle's ignition state is OFF, power is supplied to the vehicle load via a direct circuit. Therefore, the cost of the power supply system can be reduced without setting up another circuit that directly connects the main power supply to the vehicle load. Attached Figure Description

[0009] Figure 1 This is a functional block diagram of a power supply circuit and its peripheral components according to an embodiment of the present invention.

[0010] Figure 2 This is a schematic diagram illustrating the power supply status to the vehicle-mounted load.

[0011] Figure 3 This is a schematic diagram illustrating the power supply status to the vehicle-mounted load. Detailed Implementation

[0012] The power supply circuit based on the present invention implements the vehicle power pass-through function even when the vehicle is in IG-OFF mode, and supplies power from the main power supply to the vehicle load via the pass-through circuit.

[0013] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0014] <Implementation Method>

[0015] [structure]

[0016] Figure 1 This is a functional block diagram of a power supply circuit 100 and its peripheral parts according to an embodiment of the present invention. Figure 1 The illustrated functional block includes a power supply circuit 100, a door unlocking device 200, and a main power supply 300. The power supply circuit 100, door unlocking device 200, and main power supply 300 are mounted in vehicles, etc.

[0017] The main power supply 300 is a power supply source that supplies power at a specified voltage (+B voltage) to the power supply circuit 100 and the door unlocking device 200. The main power supply 300 is composed of a rechargeable secondary battery (e.g., a lithium-ion battery).

[0018] The power supply circuit 100 is a unit (redundant power supply circuit) that serves as an auxiliary power source for the backup power supply to the door unlocking device 200 when an abnormality occurs in the power supply from the main power supply 300 to the door unlocking device 200 due to a power failure (voltage loss, etc.) in the main power supply 300. This power supply circuit 100 includes a direct-connect function unit 110, a switch 120, an auxiliary power supply 130, a DC-DC converter 140, and a control unit 150.

[0019] The direct-connection function unit 110 is a structure connected to the main power supply 300 and used to supply power from the main power supply 300 to the door unlocking device 200. The direct-connection function unit 110 is typically composed of a switching element such as a semiconductor relay, and controls the on / off state of the switching element according to the instruction of the control unit 150, thereby switching the electrical connection state between the main power supply 300 and the door unlocking device 200.

[0020] The switch 120, composed of a switching element such as a semiconductor relay, is inserted between the connection point of the direct-connection function unit 110 and the DC-DC converter 140 and the door unlocking device 200. According to the instruction of the control unit 150, the switch 120 is controlled to be in an on state when power needs to be supplied to the door unlocking device 200 from the main power supply 300 or the auxiliary power supply 130, and is controlled to be in an off state at other times.

[0021] The auxiliary power source 130 is, for example, an auxiliary power supply source composed of energy storage components such as capacitors or secondary batteries such as lithium-ion batteries. The auxiliary power source 130 is connected to the DC-DC converter 140 via the direct-connect function unit 110 so as to charge the power input from the main power source 300 and to discharge the power stored therein (backup power) to the door unlocking device 200.

[0022] The DC-DC converter 140 is a power converter used to control the charging and discharging of the power from the auxiliary power supply 130. This DC-DC converter 140 can, according to the instructions of the control unit 150, convert power input from the main power supply 300 via the direct-connect function unit 110 into power of a predetermined voltage and output it to the auxiliary power supply 130, or convert power stored in the auxiliary power supply 130 into power of a predetermined voltage and output it to the door unlocking device 200.

[0023] In the aforementioned power supply circuit 100, the direct-through function unit 110 and the switch 120 constitute a direct-through circuit, while the auxiliary power supply 130, the DC-DC converter 140, and the switch 120 constitute a redundant circuit.

[0024] The control unit 150 is a structure used to control the operation of the direct-access function unit 110, the switch 120, and the DC-DC converter 140 to realize the power supply to the door unlocking device 200 via the power supply circuit 100. A microcontroller or similar device is used in this control unit 150.

[0025] The door unlocking device 200 is an on-board load that controls the locking / unlocking of vehicle doors via electrical signals. When the main power supply 300 is normal, the door unlocking device 200 operates using power supplied from the main power supply 300 via the direct-connect function 110 of the power supply circuit 100 (+B direct-connect power) (normal control). When the main power supply 300 fails, it operates using power supplied from the auxiliary power supply 130 via the DC-DC converter 140 (backup control).

[0026] In addition, as an on-board load that requires redundant power supply and is connected to the power supply circuit 100, besides Figure 1In addition to the door unlocking device 200 shown, there are also a shift-by-wire (SBW) device that changes the gear position of the transmission via electrical signals, and a braking (BRK) device that can generate braking force for the vehicle.

[0027] [action]

[0028] use Figure 2 and Figure 3 The power supply operation to the door unlocking device 200 implemented by the power supply circuit 100 according to this embodiment will be described.

[0029] (1) The main power supply is normal.

[0030] When the main power supply 300 is fault-free and in a normal state, the power supply circuit 100 implements the vehicle power supply direct-through function to electrically connect the direct-through function unit 110, regardless of the vehicle's ignition status.

[0031] Through this control, such as Figure 2 As indicated by the arrow, even when the vehicle's ignition is in the OFF state (IG-OFF), the main power supply 300 supplies power to the door unlocking device 200 via the direct-connect function 110 and the switch 120.

[0032] (2) The main power supply failed.

[0033] In the event of a failure of the main power supply 300 and an abnormal state, the power supply circuit 100 implements a backup function to electrically disconnect the direct-connection function unit 110.

[0034] Through this control, such as Figure 3 As indicated by the arrow, the power from the auxiliary power supply 130 is supplied to the door unlocking device 200 via the DC-DC converter 140 and the switch 120.

[0035] <Function / Effect>

[0036] As described above, the power supply circuit (redundant power supply circuit) 100 according to an embodiment of the present invention is provided with a pass-through function unit 110 that can be controlled to be turned on / off by the control unit 150, forming a pass-through circuit that can supply power even when the vehicle's ignition is in the OFF state (IG-OFF).

[0037] With this direct circuit, there is no need for another circuit to directly connect the main power supply 300 to vehicle loads such as the door unlocking device 200, thus enabling an overall cost reduction for the power system, including the power supply circuit 100.

[0038] The above describes one embodiment of the present invention. However, the present invention can be used not only as a power supply circuit, but also as a control method for a power supply circuit, a program for the control method, a computer-readable non-transitory storage medium storing the program, and a vehicle equipped with a power supply circuit.

[0039] The power supply circuit of the present invention can be used in vehicles and the like that want to provide backup power to onboard loads from an auxiliary power source when the main power source fails.

[0040] Symbol Explanation

[0041] 100-Power supply circuit (redundant power supply circuit), 110-Direct-through function unit, 120-Switch, 130-Auxiliary power supply, 140-DC-DC converter, 150-Control unit, 200-Door unlocking device, 300-Main power supply.

Claims

1. A power supply circuit for supplying power to an on-board load, the power supply circuit being characterized by comprising: A through circuit, inserted between the main power supply and the vehicle load, controls the power supply from the main power supply to the vehicle load; and A redundant circuit, which controls the power supply from the auxiliary power source to the on-board load when the main power source fails, The bypass circuit supplies power from the main power supply to the vehicle load even when the vehicle's ignition is off, provided that the main power supply is not faulty.

2. The power supply circuit according to claim 1, characterized in that, The vehicle-mounted load is a door unlocking device.

Images