CN218888396U

CN218888396U - Power supply circuit for vehicle control panel

Info

Publication number: CN218888396U
Application number: CN202223417128.7U
Authority: CN
Inventors: 苏伟; 胡景林; 张潮; 岳超; 薛振东
Original assignee: Beijing Environment Sanitation Engineering Group Co., Ltd.
Current assignee: Beijing Environment Sanitation Engineering Group Co., Ltd.
Priority date: 2022-12-20
Filing date: 2022-12-20
Publication date: 2023-04-18
Anticipated expiration: 2032-12-20

Abstract

The utility model provides a control panel power supply circuit for vehicle. This control panel power supply circuit for vehicle includes: a power supply; the pre-voltage stabilizing module can convert the initial voltage into a first direct current voltage; the common mode rejection module can reject the common mode electromagnetic interference signal of the pre-voltage stabilization module; the low dropout voltage stabilizing module comprises at least three low dropout voltage stabilizing circuits, and each low dropout voltage stabilizing circuit takes the first direct current voltage as the input voltage and takes the second direct current voltage as the output voltage; and the differential mode suppression module can suppress the differential mode electromagnetic interference signal output by the low dropout voltage stabilizing module. The technical scheme of the utility model control panel power supply circuit for vehicle can solve and adopt current power supply mode to supply power for control circuit, and high frequency electromagnetic interference noise is too big, leads to the relatively poor problem of system electromagnetic compatibility.

Description

Power supply circuit for vehicle control panel

Technical Field

The utility model relates to an automobile application technical field particularly, relates to a control panel power supply circuit for vehicle.

Background

With the development of power electronic technology, besides the basic functions of the circuit in the control circuit board, electromagnetic compatibility becomes a new concern of the power electronic technology. In the application fields of electric vehicles and intelligent vehicles, a system with low electromagnetic interference and excellent electromagnetic compatibility becomes one of the key factors for stable operation of vehicles. The stable operation of the CPU of the control circuit board in the automobile field has important significance for the safety of vehicles, and the stability of the CPU processor is directly influenced by the external power supply quality.

In the application field of electric vehicles and intelligent vehicles, the power supply mode of the conventional control circuit is primary power supply, the load voltage required by a controller is directly converted into high frequency through input voltage, the system adopts a switching power supply control technology, but the high frequency PWM switching noise output is not effectively inhibited, the power is directly supplied to a CPU processor and various electronic chips, the high frequency electromagnetic interference noise is too large, and the system electromagnetic compatibility is poor.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a control panel power supply circuit for vehicle can solve and adopt current power supply mode to supply power for control circuit, and high frequency electromagnetic interference noise is too big, leads to the relatively poor problem of system electromagnetic compatibility.

In order to achieve the above object, according to an aspect of the present invention, there is provided a control panel power supply circuit for a vehicle, including: the power supply is used for providing initial voltage; the power supply is connected with the input end of the pre-voltage stabilizing module, and the pre-voltage stabilizing module can convert the initial voltage into a first direct current voltage; the common mode rejection module is connected with the input end of the pre-voltage stabilization module and can reject the common mode electromagnetic interference signal of the pre-voltage stabilization module; the low-dropout voltage stabilizing module is connected with the input end of the common mode rejection module and comprises at least three low-dropout voltage stabilizing circuits, each low-dropout voltage stabilizing circuit takes a first direct-current voltage as an input voltage and takes a second direct-current voltage as an output voltage, and the voltage value of the second direct-current voltage is smaller than that of the first direct-current voltage; the input end of the differential mode suppression module is connected with the output end of the low-dropout voltage stabilizing module, the output end of the differential mode suppression module is connected with a power supply load, and the differential mode suppression module can suppress differential mode electromagnetic interference signals output by the low-dropout voltage stabilizing module.

Further, the pre-voltage-stabilizing module comprises a flyback switching power supply circuit.

Furthermore, each low dropout voltage regulator circuit is a linear voltage regulator circuit, each linear voltage regulator circuit is arranged in parallel, and the voltage values of the first direct current voltages input into each linear voltage regulator circuit are the same.

Furthermore, the common mode rejection module comprises a common mode inductor, one end of the common mode inductor is connected with the output end of the pre-voltage stabilization module, and the other end of the common mode inductor is connected with the input end of the low-dropout voltage stabilization module.

Furthermore, each linear voltage stabilizing circuit comprises a power management chip and a feedback resistor, wherein a voltage input end of the power management chip and an enabling input end of the power management chip are connected with the common-mode inductor, a first end of the feedback resistor is connected with a voltage output end of the power management chip, and a second end of the feedback resistor is connected with a regulating end of the power management chip.

Furthermore, each linear voltage stabilizing circuit also comprises a regulating resistor, and the second end of the feedback resistor is connected with one end of the regulating resistor.

Furthermore, the common mode rejection module further comprises a first capacitor, the flyback switching power supply circuit comprises a first filter capacitor and a first diode, the first filter capacitor and the first capacitor are arranged in parallel, and one end of the first filter capacitor and one end of the first capacitor are both connected with the cathode of the first diode.

Furthermore, the flyback switching power supply circuit further comprises a second diode, a transformer, a power supply control chip and a switching tube, wherein the anode of the power supply is connected with one end of the transformer, the cathode of the power supply is connected with the source electrode of the switching tube, the second diode is connected with the switching tube in parallel, and the power supply control chip is used for chopping the direct-current voltage to form alternating-current voltage and outputting alternating-current power.

Furthermore, the common mode rejection module further comprises a second capacitor, one end of the common mode inductor is connected with the cathode of the first diode, and the other end of the common mode inductor is connected with one end of the second capacitor.

Furthermore, the number of the differential mode suppression modules is multiple, the output end of each linear voltage stabilizing circuit is provided with one differential mode suppression module, each differential mode suppression module comprises a second filter capacitor, a third filter capacitor and a differential mode inductor, one end of the differential mode inductor is connected with the voltage output end of the power management chip, the other end of the differential mode inductor is connected with the third filter capacitor, and one end of the second filter capacitor is connected with the voltage output end of the power management chip.

Use the technical scheme of the utility model, be provided with power supply, voltage stabilizing module in advance, common mode suppression module, low dropout voltage stabilizing module and differential mode suppression module, power supply's voltage forms stable first DC voltage through voltage stabilizing module vary voltage in advance after, the first DC voltage input common mode suppression module of output after voltage stabilizing module vary voltage in advance, common mode suppression module can restrain the inherent common mode electromagnetic interference signal of voltage stabilizing module in advance, low dropout voltage stabilizing module includes at least three low dropout voltage stabilizing circuit, low dropout voltage stabilizing circuit can realize accurate steady voltage, can also effectively restrain the high frequency noise that voltage stabilizing module produced in advance, realize differential mode signal suppression and high performance's voltage output through differential mode suppression module at last. High-frequency noise can be effectively removed through the arrangement, the electromagnetic compatibility of the power supply circuit of the control panel for the vehicle is improved, and the working stability of the power supply circuit of the control panel for the vehicle can be further ensured.

Drawings

The accompanying drawings, which form a part of the specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to constitute a limitation on the invention. In the drawings:

fig. 1 shows a schematic diagram of a power supply circuit for a control panel for a vehicle of the present invention;

fig. 2 shows a schematic circuit diagram of the power supply circuit for a control panel for a vehicle according to the present invention; and

fig. 3 shows a schematic diagram of a vehicle control panel power supply circuit according to a first embodiment of the present invention.

Wherein the figures include the following reference numerals:

10. a power supply; 20. a pre-voltage stabilization module; 21. a transformer; 22. a first diode; 23. a power supply control chip; 24. a switching tube; 25. a first filter capacitor; 26. a second diode; 30. a common mode rejection module; 31. a common mode inductor; 32. a first capacitor; 33. a second capacitor; 40. a low-pressure-difference voltage stabilizing module; 41. a low dropout voltage regulator circuit; 42. a power management chip; 43. a feedback resistor; 44. adjusting the resistance; 50. a differential mode suppression module; 51. a second filter capacitor; 52. a third filter capacitor; 53. and (3) differential mode inductance.

Detailed Description

It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

Referring to fig. 1 and fig. 2 in combination, the utility model provides a control panel power supply circuit for vehicle, this control panel power supply circuit for vehicle includes: a power supply 10 for supplying an initial voltage; the power supply 10 is connected with the input end of the pre-voltage regulation module 20, and the pre-voltage regulation module 20 can convert the initial voltage into a first direct current voltage; the common mode rejection module 30, an input end of the common mode rejection module 30 is connected with an output end of the pre-regulator module 20, and the common mode rejection module 30 can reject the common mode electromagnetic interference signal of the pre-regulator module 20; the low dropout voltage stabilizing module 40 is characterized in that the input end of the low dropout voltage stabilizing module 40 is connected with the output end of the common mode suppression module 30, the low dropout voltage stabilizing module 40 comprises at least three low dropout voltage stabilizing circuits 41, each low dropout voltage stabilizing circuit 41 takes a first direct current voltage as an input voltage and takes a second direct current voltage as an output voltage, and the voltage value of the second direct current voltage is smaller than that of the first direct current voltage; the differential mode suppression module 50 has an input end connected to an output end of the low dropout regulator module 40, an output end connected to a power supply load, and the differential mode suppression module 50 is capable of suppressing the differential mode electromagnetic interference signal output by the low dropout regulator module 40.

In this embodiment, the voltage of the power supply 10 is transformed by the pre-regulator module 20 to form a stable first dc voltage, and since the input terminal of the common mode rejection module 30 is connected to the output terminal of the pre-regulator module 20, the first dc voltage transformed and output by the pre-regulator module 20 is input to the common mode rejection module 30, and the common mode rejection module 30 can reject the common mode electromagnetic interference signal inherent to the pre-regulator module 20. The low dropout regulator module 40 includes at least three low dropout regulator circuits 41, and the low dropout regulator circuit 41 can realize accurate voltage stabilization, and can also effectively suppress the high frequency noise generated by the pre-regulator module 20, and meanwhile, the low dropout regulator module 40 needs to effectively suppress and match the high frequency noise of the pre-regulator module 20. In addition, the voltage values of the second dc voltages output by the low dropout voltage regulator circuit 41 may be the same or different, and a user may adjust the low dropout voltage regulator circuit 41 according to the load requirement, so that the second dc voltages output by the low dropout voltage regulator circuit 41 can meet the power supply requirement. Finally, the differential mode suppression module 50 can suppress the differential mode signal and output high-performance voltage. High-frequency noise can be effectively removed through the arrangement, the electromagnetic compatibility of the power supply circuit of the control panel for the vehicle is improved, and the working stability of the power supply circuit of the control panel for the vehicle can be further ensured.

In one embodiment of the present invention, the pre-voltage regulation module 20 includes a flyback switching power supply circuit.

In this embodiment, the pre-regulator module 20 includes a flyback switching power supply circuit, which has a relatively simple circuit, a small size, a low cost, and a high power and efficiency.

Referring to fig. 1 and fig. 2, in an embodiment of the present invention, each low dropout voltage regulator circuit 41 is a linear voltage regulator circuit, each linear voltage regulator circuit is connected in parallel, and the voltage values of the first dc voltages input into each linear voltage regulator circuit are the same.

By the arrangement, high-frequency noise can be effectively removed, the electromagnetic compatibility of the system is improved, the number of the linear voltage stabilizing circuits in the low dropout voltage stabilizing module 40 can be set according to actual needs, the load expansibility is good, and the interference among loads is small.

Referring to fig. 1 and fig. 2 together, in an embodiment of the present invention, the common mode rejection module 30 includes a common mode inductor 31, one end of the common mode inductor 31 is connected to the output end of the pre-regulator module 20, and the other end of the common mode inductor 31 is connected to the input end of the low dropout regulator module 40.

In the present embodiment, one end of the common-mode inductor 31 is connected to the output end of the pre-regulator module 20, so that the common-mode interference inherent to the pre-regulator module 20 can be suppressed.

Referring to fig. 1 and fig. 2 in combination, in an embodiment of the present invention, each linear voltage stabilizing circuit includes a power management chip 42 and a feedback resistor 43, a voltage input end of the power management chip 42 and an enable input end of the power management chip 42 are connected to the common mode inductor 31, a first end of the feedback resistor 43 is connected to a voltage output end of the power management chip 42, a second end of the feedback resistor 43 is connected to a regulation end of the power management chip 42, each linear voltage stabilizing circuit further includes a regulation resistor 44, and a second end of the feedback resistor 43 is connected to one end of the regulation resistor 44.

Through the setting, can realize accurate steady voltage, adopt linear power supply itself no longer to produce high frequency noise simultaneously, through the parameter of the frequency channel rational design linear power supply who combines voltage stabilizing module 20 high frequency switching noise in advance, can also realize the effective suppression to voltage stabilizing module 20 high frequency noise in advance.

In an embodiment of the present invention, the power management chip 42 may be an NCV5663 chip.

Referring to fig. 1 and fig. 2 in combination, in an embodiment of the present invention, the common mode rejection module 30 further includes a first capacitor 32, the flyback switching power supply circuit includes a first filter capacitor 25 and a first diode 22, the first filter capacitor 25 is connected in parallel with the first capacitor 32, and one end of the first filter capacitor 25 and one end of the first capacitor 32 are both connected to the cathode of the first diode 22. The flyback switching power supply circuit further comprises a second diode 26, a transformer 21, a power supply control chip 23 and a switching tube 24, wherein the anode of the power supply 10 is connected with one end of the transformer 21, the cathode of the power supply 10 is connected with the source electrode of the switching tube 24, the second diode 26 is connected with the switching tube 24 in parallel, and the power supply control chip 23 is used for chopping the direct-current voltage to form alternating-current voltage and outputting alternating-current power. The common mode rejection module 30 further includes a second capacitor 33, one end of the common mode inductor 31 is connected to the cathode of the first diode 22, and the other end of the common mode inductor 31 is connected to one end of the second capacitor 33.

Through the arrangement, the flyback switching power supply circuit can realize high-frequency voltage transformation and form stable first direct-current voltage, and the common mode rejection module 30 can perform noise filtering, so that the vehicle control panel power supply circuit can realize high-efficiency energy transformation and can also reject high-frequency noise, and further the stability of the vehicle control panel power supply circuit is improved.

Specifically, the first capacitor 32 and the second capacitor 33 are both X capacitors.

Referring to fig. 1 and fig. 2 in combination, in an embodiment of the present invention, the number of the differential mode suppression modules 50 is plural, the output end of each linear voltage stabilizing circuit is provided with one differential mode suppression module 50, each differential mode suppression module 50 includes a second filter capacitor 51, a third filter capacitor 52 and a differential mode inductor 53, one end of the differential mode inductor 53 is connected to the voltage output end of the power management chip 42, the other end of the differential mode inductor 53 is connected to the third filter capacitor 52, and one end of the second filter capacitor 51 is connected to the voltage output end of the power management chip 42.

Through the arrangement, low electromagnetic interference and high-performance voltage output can be realized.

The first embodiment is as follows:

the power supply 10 in the first embodiment adopts a 12V storage battery, the working voltage range of which is 9V-18V, and it is assumed that a CPU processor control circuit of an on-board control circuit board needs 5V power supply, 3.3V power supply and 1.8V power supply, so as to realize the power supply requirements changing from the 12V storage battery to the 5V,3.3V and 1.8V power supply required by the on-board control circuit.

Wherein, the storage battery is represented by P, the transformer 21 is represented by T1, the switch tube 24 is represented by Q1, the first diode 22 is represented by D1, the second diode 26 is represented by D2, the first filter capacitor 25 is represented by C1, the first capacitor 32 is selected from X capacitor and is represented by C2, the common mode inductor 31 is represented by T2, and the second capacitor 33 is selected from X capacitor and is represented by C3; the low dropout voltage stabilizing module 40 comprises three low dropout voltage stabilizing circuits, namely a low dropout 5V voltage stabilizing circuit, a low dropout 3.3V voltage stabilizing circuit and a low dropout 1.8V voltage stabilizing circuit; the number of the differential mode suppression modules 50 is three, and the differential mode suppression modules are respectively a 5V output LC filter circuit, a 3.3V output LC filter circuit and a 1.8V output LC filter circuit; the number of the power management chips 42 is three, and NCV5663 chips are selected and respectively represented by U1, U2 and U3; the number of the feedback resistors 43 is three, and the feedback resistors are respectively represented by R1, R3, and R5, and the number of the adjustment resistors 44 is three, and the adjustment resistors are respectively represented by R2, R4, and R6; the number of differential mode inductors 53 is three, and is represented by L1, L2, and L3, the number of second filter capacitors 51 is three, and is represented by C4, C5, and C6, and the number of third filter capacitors 52 is three, and is represented by C7, C8, and C9.

As shown in fig. 3, the specific circuit connection relationship is as follows: the positive electrode of P is connected with one end of T1, the negative electrode of P is connected with the source electrode of Q1, the cathode of D1 is connected with one end of C1, the cathode of D1 is connected with one end of an X capacitor C2, the cathode of D1 is connected with one end of T2, the other end of T2 is connected with one end of C3, T2 is connected with the Vin end and the En end of U1, T2 is connected with the Vin end and the En end of U2, T2 is connected with the Vin end and the En end of U3, the Vout end of U1 is connected with one end of R1, and the other end of R1 is connected with one end of R2 and connected to the Adj end of U1; the Vout end of the U2 is connected with one end of the R3, and the other end of the R3 is connected with one end of the R4 and connected to the Adj end of the U2; the Vout end of U3 is connected with one end of R5, and the other end of R5 is connected with one end of R6 and connected to the Adj end of U3; the Vout end of U1 is connected with one ends of C4 and L1, the Vout end of U2 is connected with one ends of C5 and L2, and the Vout end of U3 is connected with one ends of C6 and L3; the output end of the L1 is connected with the C7 and is simultaneously connected with the 5V power supply load, the output end of the L2 is connected with the C8 and is simultaneously connected with the 3.3V power supply load, and the output end of the L3 is connected with the C9 and is simultaneously connected with the 1.8V power supply load. It should be noted that the Vin terminal refers to a voltage input terminal of the power management chip 42, the En terminal refers to an enable input terminal of the power management chip 42, the Adj terminal refers to a regulation terminal of the power management chip 42, and the Vout terminal refers to a voltage output terminal of the power management chip 42.

In this embodiment, the low dropout regulator module 40 includes three low dropout regulator circuits 41, as shown in fig. 3, the three low dropout regulator circuits 41 are a 5V low dropout regulator circuit, a 3.3V low dropout regulator circuit, and a 1.8V low dropout regulator circuit from top to bottom, respectively, and the output terminal of the pre-regulator module 20 is connected to the input terminal of the 5V low dropout regulator circuit, the input terminal of the 3.3V low dropout regulator circuit, and the input terminal of the 1.8V low dropout regulator circuit, respectively. Meanwhile, the output end of the 5V low dropout voltage regulator circuit is connected to a 5V power supply load (not shown in the figure), the output end of the 3.3V low dropout voltage regulator circuit is connected to a 3.3V power supply load (not shown in the figure), and the output end of the 1.8V low dropout voltage regulator circuit is connected to a 1.8V power supply load (not shown in the figure). The 12V storage battery voltage is firstly converted into 6V stable output bus voltage through a flyback switching power supply pre-stabilized voltage supply, and the switching power supply can ensure the conversion efficiency of the system, then the 6V output voltage is filtered through a common mode suppression module 30, then the 6V output voltage is converted into 5V output voltage with high stability and low noise through a U1 chip NCV5663 from 6V to 5V, the 6V stable voltage is converted into 3.3V output voltage with high stability and low noise through a U2 chip NCV5663 from 6V to 3.3V, and the 6V stable voltage is converted into 1.8V output voltage with high stability and low noise through a U3 chip NCV5663 from 6V to 1.8V. Finally, the 5V output voltage supplies power to the 5V load of the control circuit, the 3.3V output voltage supplies power to the 3.3V load of the control circuit, and the 1.8V output voltage supplies power to the 1.8V load of the control circuit. The high-efficiency energy conversion of the first level is realized through 6V bus voltage, the common mode rejection is realized through the common mode inductor 31 and the X capacitor, meanwhile, the NCV5663 can effectively reject the switching noise of the flyback switching power supply, and finally, the low electromagnetic interference output is realized through LC filtering.

From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: the control panel power supply circuit for the vehicle has the advantages of high system conversion efficiency, low high-frequency switching noise, good load expansibility, small mutual interference of multiple loads and the like.

It is obvious that the above described embodiments are only some of the embodiments of the present invention, and not all of them. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts shall belong to the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present application. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A control board power supply circuit for a vehicle, characterized by comprising:

a power supply (10) for providing an initial voltage;

the power supply (10) is connected with the input end of the pre-voltage-stabilizing module (20), and the pre-voltage-stabilizing module (20) can convert the initial voltage into a first direct-current voltage;

a common mode rejection module (30), an input end of the common mode rejection module (30) is connected with an output end of the pre-regulated voltage module (20), and the common mode rejection module (30) can reject a common mode electromagnetic interference signal of the pre-regulated voltage module (20);

the input end of the low-dropout voltage stabilizing module (40) is connected with the output end of the common mode rejection module (30), the low-dropout voltage stabilizing module (40) comprises at least three low-dropout voltage stabilizing circuits (41), each low-dropout voltage stabilizing circuit (41) takes the first direct-current voltage as input voltage and takes the second direct-current voltage as output voltage, and the voltage value of the second direct-current voltage is smaller than that of the first direct-current voltage;

the input end of the differential mode suppression module (50) is connected with the output end of the low dropout voltage regulator module (40), the output end of the differential mode suppression module (50) is connected with a power supply load, and the differential mode suppression module (50) can suppress the differential mode electromagnetic interference signal output by the low dropout voltage regulator module (40).

2. The vehicular control panel power supply circuit according to claim 1, wherein the pre-regulator module (20) comprises a flyback switching power supply circuit.

3. The power supply circuit for a control board for a vehicle according to claim 2, wherein each of said low dropout voltage regulator circuits (41) is a linear regulator circuit, each of said linear regulator circuits is provided in parallel, and a voltage value of said first direct current voltage inputted to each of said linear regulator circuits is the same.

4. The vehicle control board power supply circuit according to claim 3, wherein the common mode rejection module (30) comprises a common mode inductor (31), one end of the common mode inductor (31) is connected to the output terminal of the pre-regulator module (20), and the other end of the common mode inductor (31) is connected to the input terminal of the low dropout regulator module (40).

5. The vehicle control board power supply circuit according to claim 4, wherein each linear voltage regulator circuit comprises a power management chip (42) and a feedback resistor (43), a voltage input terminal of the power management chip (42) and an enable input terminal of the power management chip (42) are connected to the common mode inductor (31), a first end of the feedback resistor (43) is connected to a voltage output terminal of the power management chip (42), and a second end of the feedback resistor (43) is connected to a regulating terminal of the power management chip (42).

6. The vehicular control panel power supply circuit according to claim 5, wherein each of the linear voltage stabilizing circuits further includes a regulating resistor (44), and a second terminal of the feedback resistor (43) is connected to one terminal of the regulating resistor (44).

7. The vehicle control panel power supply circuit according to claim 4, wherein the common mode rejection module (30) further comprises a first capacitor (32), the flyback switching power supply circuit comprises a first filter capacitor (25) and a first diode (22), the first filter capacitor (25) is connected in parallel with the first capacitor (32), and one end of each of the first filter capacitor (25) and the first capacitor (32) is connected to a cathode of the first diode (22).

8. The vehicle control panel power supply circuit according to claim 2, wherein the flyback switching power supply circuit further includes a second diode (26), a transformer (21), a power supply control chip (23), and a switching tube (24), wherein an anode of the power supply (10) is connected to one end of the transformer (21), a cathode of the power supply (10) is connected to a source of the switching tube (24), the second diode (26) is connected in parallel to the switching tube (24), and the power supply control chip (23) is configured to chop a dc voltage to form an ac voltage and output an ac current.

9. The vehicle control board power supply circuit according to claim 7, wherein the common mode rejection module (30) further comprises a second capacitor (33), one end of the common mode inductor (31) is connected to the cathode of the first diode (22), and the other end of the common mode inductor (31) is connected to one end of the second capacitor (33).

10. The vehicle control board power supply circuit according to claim 5, wherein the number of the differential mode suppression modules (50) is plural, one differential mode suppression module (50) is disposed at an output end of each linear voltage stabilizing circuit, each differential mode suppression module (50) includes a second filter capacitor (51), a third filter capacitor (52) and a differential mode inductor (53), one end of the differential mode inductor (53) is connected to a voltage output end of the power management chip (42), the other end of the differential mode inductor (53) is connected to the third filter capacitor (52), and one end of the second filter capacitor (51) is connected to a voltage output end of the power management chip (42).