Automobile load power supply circuit and device

Abstract

The invention discloses an automobile load power supply circuit and device, and relates to the technical field of power control, the automobile load power supply circuit comprises a first switch circuit, a second switch circuit and a third switch circuit, when an automobile ignition switch is closed, the first switch circuit is conducted, then the third switch circuit is conducted, and the second switch circuit is switched on; when the automobile ignition switch is switched off, the controller and / or the transceiver controls the first switching circuit to be switched on, and / or the controller controls the second switching circuit to be switched on, so that the third switching circuit is maintained to be switched on, and a control signal can be output through the automobile ignition switch or the control signal can be continuously output through the transceiver. When the controller is reset or breaks down, the self-locking function and power supply of the automobile load power supply circuit are still maintained, and the stable working state of the circuit is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply control, and in particular to an automobile load power supply circuit and device. Background Art

[0002] A self-locking circuit is a special circuit. Once the self-locking switch in the circuit is turned on, the circuit can automatically remain powered on until the self-locking switch is turned off, so that the circuit can maintain a stable working state under specific conditions.

[0003] In the prior art, after the ignition signal of the vehicle is disconnected, the controller continuously outputs a control signal to replace the ignition signal of the vehicle to maintain the self-locking switch on, so as to realize the self-locking function of the load power supply circuit. However, the control signal of the controller will fail when the controller is reset or fails, which will cause the vehicle load power supply circuit to fail to maintain the self-locking function and be powered off. Summary of the invention

[0004] The embodiment of the present invention provides an automobile load power supply circuit and device to solve the technical problem in the related art that the existing automobile load power supply circuit realizes the self-locking function by continuously outputting a control signal through a controller, which causes the self-locking function to fail when the controller is reset or fails.

[0005] In a first aspect, a vehicle load power supply circuit is provided, comprising:

[0006] A first switch circuit, the first switch circuit is used to connect with a first interface of the controller, a transceiver, and an automobile ignition switch;

[0007] a second switch circuit, the second switch circuit being used to connect to the first interface of the controller;

[0008] a third switch circuit, the third switch circuit being connected to a power supply and a load, and the third switch circuit being further connected to the first switch circuit and the second switch circuit;

[0009] When the ignition switch of the automobile is closed, the first switch circuit is turned on, thereby turning on the third switch circuit;

[0010] When the ignition switch of the automobile is turned off, the controller and / or the transceiver controls the first switch circuit to be turned on, and / or the controller controls the second switch circuit to be turned on, so as to maintain the third switch circuit to be turned on.

[0011] In some embodiments, the first switch circuit includes:

[0012] A first diode D1, wherein the anode of the first diode D1 is connected to the automobile ignition switch;

[0013] a first resistor R1, wherein a first end of the first resistor R1 is connected to a cathode of the first diode D1;

[0014] a first transistor Q1, wherein the base of the first transistor Q1 is connected to the second end of the first resistor R1, the base of the first transistor Q1 is also connected to the second interface of the controller, the collector of the first transistor Q1 is connected to the third switch circuit, and the emitter of the first transistor Q1 is grounded;

[0015] A second resistor R2, wherein a first end of the second resistor R2 is connected to the second end of the first resistor R1 and the base of the first transistor Q1, and a second end of the second resistor R2 is grounded.

[0016] In some embodiments, the first switch circuit further includes:

[0017] A suppression diode TVS1, wherein a first end of the suppression diode TVS1 is connected to the automobile ignition switch and the positive electrode of the first diode D1, and a second end of the suppression diode TVS1 is grounded;

[0018] A first capacitor C1 , wherein a first end of the first capacitor C1 is connected to the second end of the first resistor R1 and the base of the first transistor Q1 , and a second end of the first capacitor C1 is grounded.

[0019] In some embodiments, the first switch circuit further includes:

[0020] a second diode D2, wherein an anode of the second diode D2 is connected to the transceiver;

[0021] A seventh resistor R7, wherein a first end of the seventh resistor R7 is connected to the cathode of the second diode D2, and a second end of the seventh resistor R7 is connected to the base of the first transistor Q1.

[0022] In some embodiments, the second switch circuit includes:

[0023] A third resistor R3, a first end of the third resistor R3 is connected to the first interface of the controller;

[0024] a fourth resistor R4, wherein a first end of the fourth resistor R4 is connected to a second end of the third resistor R3, and a second end of the fourth resistor R4 is grounded;

[0025] A second transistor Q2, the base of the second transistor Q2 is connected to the second end of the third resistor R3 and the first end of the fourth resistor R4, the base of the second transistor Q2 is also connected to the second interface of the controller, the collector of the second transistor Q2 is connected to the third switching circuit, and the emitter of the second transistor Q2 is grounded.

[0026] In some embodiments, the third switch circuit includes:

[0027] a ninth resistor R9, wherein a first end of the ninth resistor R9 is connected to the power supply, the collector of the first transistor Q1, and the collector of the second transistor Q2;

[0028] A third transistor Q3, the emitter of the third transistor Q3 is connected to the second end of the ninth resistor R9, the base of the third transistor Q3 is connected to the collector of the first transistor Q1 and the collector of the second transistor Q2, and the collector of the third transistor Q3 is connected to the load.

[0029] In some embodiments, the third switch circuit further includes:

[0030] A second capacitor C2, wherein a first end of the second capacitor C2 is connected to the collector of the third transistor Q3 and the load, and a second end of the second capacitor C2 is grounded;

[0031] an eighth resistor R8, a first end of the eighth resistor R8 is connected to the collector of the third transistor Q3 and the load, and a second end of the eighth resistor R8 is grounded;

[0032] A voltage stabilizing diode D4, wherein a cathode of the voltage stabilizing diode D4 is connected to the collector of the third transistor Q3 and the load, and an anode of the voltage stabilizing diode D4 is grounded.

[0033] In some embodiments, the automobile load power supply circuit further includes:

[0034] An overcurrent protection circuit, wherein the overcurrent protection circuit is a fourth transistor Q4, wherein the base of the fourth transistor Q4 is connected to the second end of the ninth resistor R9 and the emitter of the third transistor Q3, the emitter of the fourth transistor Q4 is connected to the first end of the ninth resistor R9 and the power supply, and the collector of the fourth transistor Q4 is connected to the base of the third transistor Q3.

[0035] In some embodiments, the automobile load power supply circuit further includes:

[0036] a sixth resistor R6, wherein a first end of the sixth resistor R6 is connected to a first end of the ninth resistor R9 and the power supply;

[0037] A fifth resistor R5, a first end of the fifth resistor R5 is connected to the second end of the sixth resistor R6 and the emitter of the fourth transistor Q4, and a second end of the fifth resistor R5 is connected to the collector of the first transistor Q1 and the collector of the second transistor Q2.

[0038] In a second aspect, a vehicle load power supply device is provided, comprising the aforementioned vehicle load power supply circuit.

[0039] The beneficial effects brought about by the technical solution provided by the present invention include:

[0040] An embodiment of the present invention provides an automobile load power supply circuit and device, wherein the automobile load power supply circuit includes a first switch circuit, a second switch circuit, and a third switch circuit, wherein the first switch circuit is used to connect to a first interface of a controller, a transceiver, and an automobile ignition switch, the second switch circuit is used to connect to the first interface of the controller, the third switch circuit is connected to a power supply and a load, and the third switch circuit is also connected to the first switch circuit and the second switch circuit, when the automobile ignition switch is closed, the first switch circuit is turned on, thereby turning on the third switch circuit, when the automobile ignition switch is turned off, the controller and / or the transceiver controls the first switch circuit to turn on, and / or the controller controls the second switch circuit to turn on, so as to maintain the third switch circuit turned on, and a control signal can be output through the automobile ignition switch or a control signal can be continuously output through the transceiver, and when the controller is reset or fails, the self-locking function and power supply of the automobile load power supply circuit are still maintained, thereby ensuring a stable working state of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 A block diagram of an automobile load power supply circuit provided by an embodiment of the present invention;

[0043] Figure 2 A schematic diagram of an automobile load power supply circuit provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] The embodiment of the present invention provides an automobile load power supply circuit and device, which can solve the technical problem in the related art that the existing automobile load power supply circuit realizes the self-locking function by continuously outputting a control signal through a controller, and when the controller is reset or fails, the self-locking function will fail.

[0046] Figure 1 An automobile load power supply circuit provided by an embodiment of the present invention includes: a first switch circuit, a second switch circuit and a third switch circuit, wherein the first switch circuit is used to connect to a first interface of a controller, a transceiver and an automobile ignition switch, the second switch circuit is used to connect to the first interface of the controller, the third switch circuit is connected to a power supply and a load, and the third switch circuit is also connected to the first switch circuit and the second switch circuit. When the automobile ignition switch is closed, the first switch circuit is turned on, thereby turning on the third switch circuit. When the automobile ignition switch is turned off, the controller and / or the transceiver controls the first switch circuit to turn on, and / or the controller controls the second switch circuit to turn on, so as to maintain the third switch circuit on.

[0047] The automobile load power supply circuit of the embodiment of the present invention is provided with a first switch circuit, a second switch circuit and a third switch circuit, wherein the first switch circuit is used to connect to a first interface of a controller, a transceiver and an automobile ignition switch, the second switch circuit is used to connect to the first interface of the controller, the third switch circuit is connected to a power supply and a load, and the third switch circuit is also connected to the first switch circuit and the second switch circuit. When the automobile ignition switch is closed, the first switch circuit is turned on, thereby turning on the third switch circuit. When the automobile ignition switch is disconnected, the controller and / or the transceiver controls the first switch circuit to be turned on, and / or the controller controls the second switch circuit to be turned on, so as to maintain the third switch circuit turned on. A control signal can be output through the automobile ignition switch or a control signal can be continuously output through the transceiver. When the controller is reset or fails, the self-locking function and power supply of the automobile load power supply circuit are still maintained, thereby ensuring a stable working state of the circuit.

[0048] As an optional implementation, in an embodiment of the invention, see Figure 2As shown, the first switch circuit includes: a first diode D1, a first resistor R1, a first transistor Q1, and a second resistor R2, wherein the anode of the first diode D1 is connected to the automobile ignition switch, the first end of the first resistor R1 is connected to the cathode of the first diode D1, the base of the first transistor Q1 is connected to the second end of the first resistor R1, the base of the first transistor Q1 is also connected to the second interface IO2 of the controller, the collector of the first transistor Q1 is connected to the third switch circuit, the emitter of the first transistor Q1 is grounded, the first end of the second resistor R2 is connected to the second end of the first resistor R1 and the base of the first transistor Q1, the second end of the second resistor R2 is grounded, and when the automobile ignition switch is closed, the high level signal IG of the automobile ignition is transmitted through the The first diode D1 and the first resistor R1 provide a control signal for the base of the first transistor Q1, and the second resistor R2 provides a base-emitter bias voltage for the first transistor Q1, so that the first transistor Q1 is turned on, and then the third switch circuit is controlled to be turned on so that the power supply VIN supplies power to the load; when it is necessary to autonomously cut off the self-locking circuit to stop the power supply VIN from supplying power, the controller sends a low-level control signal to the base of the first transistor Q1 through the second interface IO2, controls the first transistor Q1 and the third switch circuit to be disconnected, and then the power supply VIN stops supplying power to the load. The control signal is stable and not interfered by other signals, and the self-locking circuit can be autonomously cut off in time to stop the power supply from supplying power. The first diode D1 is used to prevent other current signals from flowing back, and the first resistor R1 is a voltage divider resistor used to protect the circuit.

[0049] As an optional implementation, in an embodiment of the invention, see Figure 2 As shown, the first switch circuit also includes: a suppression diode TVS1 and a first capacitor C1, the first end of the suppression diode TVS1 is connected to the automobile ignition switch and the positive electrode of the first diode D1, the second end of the suppression diode TVS1 is grounded, the first end of the first capacitor C1 is connected to the second end of the first resistor R1 and the base of the first transistor Q1, the second end of the first capacitor C1 is grounded, the suppression diode TVS1 is an overvoltage protection diode, when overvoltage appears in the circuit, the suppression diode TVS1 will quickly turn on and guide the overvoltage to the ground line, so as to protect other components in the circuit from damage by overvoltage, the first capacitor C1 is a filter capacitor, which is used to smooth the DC voltage and suppress high-frequency noise, so as to avoid the circuit from malfunctioning or being damaged due to voltage or current fluctuations.

[0050] As an optional implementation, in an embodiment of the invention, see Figure 2As shown, the first switch circuit also includes: a second diode D2 and a seventh resistor R7, the anode of the second diode D2 is connected to the transceiver, the first end of the seventh resistor R7 is connected to the cathode of the second diode D2, and the second end of the seventh resistor R7 is connected to the base of the first transistor Q1. When the transceiver wakes up and sends a control signal to the base of the first transistor Q1 through the second diode D2 and the seventh resistor R7, the second resistor R2 provides a base-emitter bias voltage for the first transistor Q1, so that the first transistor Q1 is turned on, and then the third switch circuit is controlled to turn on so that the power supply VIN supplies power to the load. The transceiver is controlled separately from the automobile ignition switch. When the automobile ignition switch is turned off, it can be controlled by the transceiver. When the controller is reset or fails, the transceiver still maintains the self-locking function and power supply of the automobile load power supply circuit. The second diode D2 is used to prevent other current signals from flowing back. The seventh resistor R7 is also a voltage divider resistor for protecting the circuit.

[0051] As an optional implementation, in an embodiment of the invention, see Figure 2 As shown, the second switch circuit includes: a third resistor R3, a fourth resistor R4 and a second triode Q2, the first end of the third resistor R3 is connected to the first interface IO1 of the controller, the first end of the fourth resistor R4 is connected to the second end of the third resistor R3, the second end of the fourth resistor R4 is grounded, the base of the second triode Q2 is connected to the second end of the third resistor R3 and the first end of the fourth resistor R4, the base of the second triode Q2 is also connected to the second interface IO2 of the controller, the collector of the second triode Q2 is connected to the third switch circuit, the emitter of the second triode Q2 is grounded, the controller sends a high level signal to the base of the second triode Q2 through the first interface IO1, and the fourth resistor R4 is the second triode Q 2 provides a base-emitter bias voltage to turn on the second transistor Q2, thereby controlling the third switch circuit to turn on so that the power supply VIN supplies power to the load; when it is necessary to cut off the self-locking circuit to stop the power supply VIN from supplying power, the controller sends a low-level control signal to the base of the second transistor Q2 through the second interface IO2 to control the second transistor Q2 and the third switch circuit to be disconnected, thereby causing the power supply VIN to stop supplying power to the load. The automobile ignition switch of the first switch circuit, the transceiver and the controller of the second switch circuit are three separate control circuits. When one of the control signals exists, the load can be powered normally. When the automobile ignition switch is disconnected or the controller is reset or both cannot provide valid signals, the self-locking can be achieved through the transceiver control to enable the power supply to supply power to the load.

[0052] As an optional implementation, in an embodiment of the invention, see Figure 2 As shown, the third switch circuit includes: a ninth resistor R9 and a third triode Q3, the first end of the ninth resistor R9 is connected to the power supply, the collector of the first triode Q1, and the collector of the second triode Q2, the emitter of the third triode Q3 is connected to the second end of the ninth resistor R9, the base of the third triode Q3 is connected to the collector of the first triode Q1 and the collector of the second triode Q2, and the collector of the third triode Q3 is connected to the load, when the first triode Q1 and the second triode Q2 are turned on at the same time or only the first triode Q1 or only the second triode Q2 is turned on, the base of the third triode Q3 is grounded and turned on, and the power supply VIN supplies power to the load through the ninth resistor R9 and the third triode Q3; when the first triode Q1 and the second triode Q2 are both turned off, the third triode Q3 is also turned off, and the power supply VIN stops supplying power to the load.

[0053] As an optional implementation, in an embodiment of the invention, see Figure 2 As shown, the third switch circuit also includes: a second capacitor C2, an eighth resistor R8 and a zener diode D4, the first end of the second capacitor C2 is connected to the collector of the third transistor Q3 and the load, the second end of the second capacitor C2 is grounded, the first end of the eighth resistor R8 is connected to the collector of the third transistor Q3 and the load, the second end of the eighth resistor R8 is grounded, the cathode of the zener diode D4 is connected to the collector of the third transistor Q3 and the load, the anode of the zener diode D4 is grounded, the second capacitor C2 can filter out high-frequency noise in the circuit, reduce the impact of noise on circuit performance, and improve circuit stability; the zener diode D4 is used to stabilize the voltage and protect the electronic components in the circuit to prevent them from being broken down by high current; the eighth resistor R8 and the zener diode D4 are used to provide protection when the load is suddenly shut down and causes a reverse pulse.

[0054] As an optional implementation, in an embodiment of the invention, see Figure 1 and Figure 2As shown, the automobile load power supply circuit also includes: an overcurrent protection circuit, the overcurrent protection circuit is a fourth transistor Q4, the base of the fourth transistor Q4 is connected to the second end of the ninth resistor R9 and the emitter of the third transistor Q3, the emitter of the fourth transistor Q4 is connected to the first end of the ninth resistor R9 and the power supply, the collector of the fourth transistor Q4 is connected to the base of the third transistor Q3, when the load is short-circuited or fails to cause overcurrent, the voltage on the ninth resistor R9 is too large to reach the turn-on voltage of the fourth transistor Q4, then the fourth transistor Q4 is turned on to short-circuit the base and emitter of the third transistor Q3, thereby disconnecting the third transistor Q3, and the power supply VIN disconnects the power supply to protect the circuit, and the maximum current of the third switch circuit is specifically determined by the turn-on voltage of the fourth transistor Q4 and the resistance value of the ninth resistor R9.

[0055] As an optional implementation, in an embodiment of the invention, see Figure 2 As shown, the automobile load power supply circuit also includes: a sixth resistor R6 and a fifth resistor R5, the first end of the sixth resistor R6 is connected to the first end of the ninth resistor R9 and the power supply, the first end of the fifth resistor R5 is connected to the second end of the sixth resistor R6 and the emitter of the fourth transistor Q4, the second end of the fifth resistor R5 is connected to the collector of the first transistor Q1 and the collector of the second transistor Q2, the sixth resistor R6 and the fifth resistor R5 are voltage-dividing resistors, when the first transistor Q1 and the second transistor Q2 are turned on at the same time or only the first transistor Q1 or only the second transistor Q2 is turned on, the sixth resistor R6 and the fifth resistor R5 divide the voltage to provide the base and emitter bias voltages for the third transistor Q3, so that the third transistor Q3 is turned on.

[0056] An embodiment of the present invention further provides an automobile load power supply device, comprising the aforementioned automobile load power supply circuit, wherein the automobile load power supply circuit comprises: a first switch circuit, a second switch circuit and a third switch circuit, wherein the first switch circuit is used to connect to a first interface of a controller, a transceiver and an automobile ignition switch, the second switch circuit is used to connect to the first interface of the controller, the third switch circuit is connected to a power supply and a load, and the third switch circuit is also connected to the first switch circuit and the second switch circuit. When the automobile ignition switch is closed, the first switch circuit is turned on, thereby turning on the third switch circuit. When the automobile ignition switch is disconnected, the controller and / or the transceiver controls the first switch circuit to turn on, and / or the controller controls the second switch circuit to turn on, so as to maintain the third switch circuit turned on.

[0057] The automobile load power supply device of the embodiment of the present invention has an automobile load power supply circuit provided with a first switch circuit, a second switch circuit and a third switch circuit, wherein the first switch circuit is used to connect to the first interface of the controller, the transceiver and the automobile ignition switch, the second switch circuit is used to connect to the first interface of the controller, the third switch circuit is connected to the power supply and the load, and the third switch circuit is also connected to the first switch circuit and the second switch circuit. When the automobile ignition switch is closed, the first switch circuit is turned on, thereby turning on the third switch circuit. When the automobile ignition switch is turned off, the controller and / or the transceiver controls the first switch circuit to be turned on, and / or the controller controls the second switch circuit to be turned on to maintain the third switch circuit turned on, and a control signal can be output through the automobile ignition switch or a control signal can be continuously output through the transceiver. When the controller is reset or fails, the self-locking function and power supply of the automobile load power supply circuit are still maintained, thereby ensuring a stable working state of the circuit.

[0058] In the description of the present invention, it should be noted that the terms "upper", "lower", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0059] It should be noted that, in the present invention, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0060] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features of the present invention.

Claims

1. An automobile load power supply circuit, characterized in that: include: A first switch circuit, the first switch circuit is used to connect with a first interface of the controller, a transceiver, and an automobile ignition switch; a second switch circuit, the second switch circuit being used to connect to the first interface of the controller; a third switch circuit, the third switch circuit being connected to a power supply and a load, and the third switch circuit being further connected to the first switch circuit and the second switch circuit; When the ignition switch of the automobile is closed, the first switch circuit is turned on, thereby turning on the third switch circuit; When the ignition switch of the automobile is turned off, the controller and / or the transceiver controls the first switch circuit to be turned on, and / or the controller controls the second switch circuit to be turned on, so as to maintain the third switch circuit to be turned on.

2. The automotive load power supply circuit according to claim 1, characterized in that: The first switch circuit comprises: A first diode D1, wherein the anode of the first diode D1 is connected to the automobile ignition switch; a first resistor R1, wherein a first end of the first resistor R1 is connected to a cathode of the first diode D1; a first transistor Q1, wherein the base of the first transistor Q1 is connected to the second end of the first resistor R1, the base of the first transistor Q1 is also connected to the second interface of the controller, the collector of the first transistor Q1 is connected to the third switch circuit, and the emitter of the first transistor Q1 is grounded; A second resistor R2, wherein a first end of the second resistor R2 is connected to the second end of the first resistor R1 and the base of the first transistor Q1, and a second end of the second resistor R2 is grounded.

3. The automobile load power supply circuit according to claim 2, characterized in that: The first switch circuit further includes: A suppression diode TVS1, wherein a first end of the suppression diode TVS1 is connected to the automobile ignition switch and the positive electrode of the first diode D1, and a second end of the suppression diode TVS1 is grounded; A first capacitor C1 , wherein a first end of the first capacitor C1 is connected to the second end of the first resistor R1 and the base of the first transistor Q1 , and a second end of the first capacitor C1 is grounded.

4. The automobile load power supply circuit according to claim 3, characterized in that: The first switch circuit further includes: a second diode D2, wherein an anode of the second diode D2 is connected to the transceiver; A seventh resistor R7, wherein a first end of the seventh resistor R7 is connected to the cathode of the second diode D2, and a second end of the seventh resistor R7 is connected to the base of the first transistor Q1.

5. The automobile load power supply circuit according to claim 2, characterized in that: The second switch circuit comprises: A third resistor R3, a first end of the third resistor R3 is connected to the first interface of the controller; a fourth resistor R4, wherein a first end of the fourth resistor R4 is connected to a second end of the third resistor R3, and a second end of the fourth resistor R4 is grounded; A second transistor Q2, the base of the second transistor Q2 is connected to the second end of the third resistor R3 and the first end of the fourth resistor R4, the base of the second transistor Q2 is also connected to the second interface of the controller, the collector of the second transistor Q2 is connected to the third switching circuit, and the emitter of the second transistor Q2 is grounded.

6. The automobile load power supply circuit according to claim 5, characterized in that: The third switch circuit comprises: a ninth resistor R9, wherein a first end of the ninth resistor R9 is connected to the power supply, the collector of the first transistor Q1, and the collector of the second transistor Q2; A third transistor Q3, the emitter of the third transistor Q3 is connected to the second end of the ninth resistor R9, the base of the third transistor Q3 is connected to the collector of the first transistor Q1 and the collector of the second transistor Q2, and the collector of the third transistor Q3 is connected to the load.

7. The automobile load power supply circuit according to claim 6, characterized in that: The third switch circuit further includes: A second capacitor C2, wherein a first end of the second capacitor C2 is connected to the collector of the third transistor Q3 and the load, and a second end of the second capacitor C2 is grounded; an eighth resistor R8, a first end of the eighth resistor R8 is connected to the collector of the third transistor Q3 and the load, and a second end of the eighth resistor R8 is grounded; A voltage stabilizing diode D4, wherein a cathode of the voltage stabilizing diode D4 is connected to the collector of the third transistor Q3 and the load, and an anode of the voltage stabilizing diode D4 is grounded.

8. The automobile load power supply circuit according to claim 6, characterized in that: Also includes: An overcurrent protection circuit, wherein the overcurrent protection circuit is a fourth transistor Q4, wherein the base of the fourth transistor Q4 is connected to the second end of the ninth resistor R9 and the emitter of the third transistor Q3, the emitter of the fourth transistor Q4 is connected to the first end of the ninth resistor R9 and the power supply, and the collector of the fourth transistor Q4 is connected to the base of the third transistor Q3.

9. The automobile load power supply circuit according to claim 8, characterized in that: Also includes: a sixth resistor R6, wherein a first end of the sixth resistor R6 is connected to a first end of the ninth resistor R9 and the power supply; A fifth resistor R5, a first end of the fifth resistor R5 is connected to the second end of the sixth resistor R6 and the emitter of the fourth transistor Q4, and a second end of the fifth resistor R5 is connected to the collector of the first transistor Q1 and the collector of the second transistor Q2.

10. An automobile load power supply device, characterized in that: The invention comprises the automobile load power supply circuit as claimed in any one of claims 1 to 9.

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