Power supply circuit and power supply of control unit

Abstract

The invention relates to a power supply circuit of a control unit and a power supply. The power supply circuit comprises a main power supply circuit of a control unit formed by connecting a main power supply and a main voltage conversion module, a standby power supply circuit of the control unit formed by connecting a standby battery and a standby voltage conversion module, an anomaly detection module and a power supply switching module, the input end of the power supply switching module is connected with the main voltage conversion module and the standby voltage conversion module through the abnormity detection module. The output end of the power supply switching module is connected with the control unit. The power supply switching module is used for cutting off a main power supply circuit of the control unit and switching on a standby power supply circuit of the control unit under the condition that the main power supply voltage is abnormal so as to supply power to the control unit through a standby battery; and when the main power supply voltage and the standby power supply voltage are abnormal, the main power supply circuit and the standby power supply circuit of the control unit are cut off at the same time. The power supply circuit can improve the power supply stability of the control unit of the power electronic equipment.

Description

Technical Field

[0001] The present application relates to the technical field of power supply, and particularly to a power supply circuit and a power supply for a control unit. Background Art

[0002] The control unit of a power electronic device plays a decisive role in realizing the intelligent, safe, and stable operation of the power electronic device. Therefore, the power supply stability of the control unit is the basis for ensuring the intelligent, safe, and stable operation of the entire power electronic device.

[0003] In the related art, in the power supply design of the control unit of a power electronic device, there are power supply schemes using a single power supply system and those using a dual power supply system. However, the existing two power supply schemes still have deficiencies such as poor reliability, high maintenance difficulty, and low anti-interference ability. This has a great impact on the power supply stability of the control unit of the power electronic device. Therefore, how to improve the power supply stability of the control unit of the power electronic device has become an urgent problem to be solved. Summary of the Invention

[0004] Based on this, in view of the above technical problems, it is necessary to provide a power supply circuit and a power supply for a control unit, which can improve the power supply stability of the control unit of a power electronic device.

[0005] In a first aspect, the present application provides a power supply circuit for a control unit. The power supply circuit includes: a main power supply circuit of the control unit formed by connecting the main power supply and the main voltage conversion module, a standby power supply circuit of the control unit formed by connecting the standby battery and the standby voltage conversion module, an abnormality detection module, and a power supply switching module; the input end of the power supply switching module is respectively connected to the main voltage conversion module and the standby voltage conversion module through the abnormality detection module, and the output end of the power supply switching module is connected to the control unit;

[0006] The abnormality detection module is configured to detect the abnormal state of the main power supply voltage output by the main voltage conversion module when the main power supply supplies power to the control unit; and detect the abnormal state of the standby power supply voltage output by the standby voltage conversion module when the standby battery supplies power to the control unit;

[0007] The power supply switching module is configured to cut off the main power supply circuit of the control unit and simultaneously conduct the standby power supply circuit of the control unit to supply power to the control unit through the standby battery when the main power supply voltage is abnormal; and cut off both the main power supply circuit and the standby power supply circuit of the control unit when both the main power supply voltage and the standby power supply voltage are abnormal.

[0008] In one embodiment, the anomaly detection module includes a first anomaly detection unit and a second anomaly detection unit. The input end of the first anomaly detection unit is connected to the main voltage conversion module, and the input end of the second anomaly detection unit is connected to the standby voltage conversion module. The output ends of the first anomaly detection unit and the second anomaly detection unit are both connected to the power supply switching module;

[0009] The first anomaly detection unit is configured to detect the abnormal state of the main power supply voltage and output a first level signal based on the abnormal state;

[0010] The second anomaly detection unit is configured to detect the abnormal state of the standby power supply voltage and output a second level signal according to the abnormal state;

[0011] The power supply switching module is configured to control the conduction and cut-off of the main power supply circuit and the standby power supply circuit according to the first level signal and the second level signal.

[0012] In one embodiment, the first anomaly detection unit includes a main voltage comparison sub-unit and a main alarm sub-unit. The input end of the main voltage comparison sub-unit is connected to the main voltage conversion module, and the output end of the main voltage comparison sub-unit is connected to the power supply switching module through the main alarm sub-unit;

[0013] The main voltage comparison sub-unit is configured to compare the main power supply voltage with a preset alarm threshold to determine the abnormal state of the main power supply voltage;

[0014] The main alarm sub-unit is configured to output a high level when the main power supply voltage is abnormal.

[0015] In one embodiment, the second anomaly detection unit includes a standby voltage comparison sub-unit and a standby alarm sub-unit. The input end of the standby voltage comparison sub-unit is connected to the standby voltage conversion module, and the output end of the standby voltage comparison sub-unit is connected to the power supply switching module through the standby alarm sub-unit;

[0016] The standby voltage comparison sub-unit is configured to compare the standby power supply voltage with a preset alarm threshold to determine the abnormal state of the standby power supply voltage;

[0017] The standby alarm sub-unit is configured to output a low level when the standby power supply voltage is abnormal.

[0018] In one embodiment, the power supply switching module includes a first switch unit and a second switch unit. The first switch unit is used to connect the first anomaly detection unit to the control unit, and the second switch unit is used to connect the second anomaly detection unit to the control unit, and the second switch unit is also connected to the first anomaly detection unit;

[0019] When the first level signal is at a low level and the second level signal is at a high level or a low level, turn on the first switching unit and turn off the second switching unit; when both the first level signal and the second level signal are at a high level, turn off the first switching unit and turn on the second switching unit; when the first level signal is at a high level and the second level signal is at a low level, turn off both the first switching unit and the second switching unit simultaneously.

[0020] In one embodiment, both the first switching unit and the second switching unit are connected to the control unit;

[0021] The control unit is configured to control the first switching unit to turn off and, control the second switching unit to turn on when the main voltage conversion module needs to be disassembled for repair.

[0022] In one embodiment, the power supply circuit further includes a main power switch module for connecting the main power supply and the main voltage conversion module, and the controlled terminal of the main power switch module is connected to the control unit;

[0023] The control unit is configured to control the main power switch module to disconnect when the main voltage conversion module needs to be disassembled for repair.

[0024] In one embodiment, the power supply circuit further includes a battery discharge switch module for connecting the backup battery and the backup voltage conversion module, and the controlled terminal of the battery discharge switch module is connected to the control unit;

[0025] The control unit is configured to control the battery discharge switch module to turn on when the backup battery meets the working conditions, so that the backup battery is in a discharging state.

[0026] In one embodiment, the power supply circuit further includes a battery charging switch module for connecting the main power supply and the backup battery, and the controlled terminal of the battery charging switch module is connected to the control unit;

[0027] The control unit is configured to control the battery charging switch module to turn on when the main power supply is supplying power and the backup battery does not meet the working conditions, so that the main power supply charges the backup battery; and, control the battery charging switch module to turn off when the backup battery is fully charged.

[0028] In a second aspect, the present application further provides a power supply, which includes the content of any one of the embodiments of the power supply circuit of the control unit in the first aspect above.

[0029] The power supply circuit and power supply of the above control unit, the main power supply circuit of the control unit formed by connecting the main power supply and the main voltage conversion module, the standby power supply circuit of the control unit formed by connecting the standby battery and the standby voltage conversion module, the abnormal detection module and the power supply switching module; the input end of the power supply switching module is respectively connected to the main voltage conversion module and the standby voltage conversion module through the abnormal detection module, and the output end of the power supply switching module is connected to the control unit; the abnormal detection module is used to detect the abnormal state of the main power supply voltage output by the main voltage conversion module when the main power supply supplies power to the control unit; when the standby battery supplies power to the control unit, detect the abnormal state of the standby power supply voltage output by the standby voltage conversion module; the power supply switching module is used to cut off the main power supply circuit of the control unit when the main power supply voltage is abnormal, and at the same time turn on the standby power supply circuit of the control unit to supply power to the control unit through the standby battery; when both the main power supply voltage and the standby power supply voltage are abnormal, cut off the main power supply circuit and the standby power supply circuit of the control unit at the same time. The power supply circuit of this control unit is provided with a main power supply circuit and a standby power supply circuit. The two power supply circuits are the main power supply and the standby battery respectively. There is no problem of mutual influence between the two during the power supply process, and the two power supply circuits do not provide power at the same time, but only provide power through one power supply circuit at the same moment. That is, when the main power supply circuit is normal, it supplies power to the control unit; when there is an abnormality in the main power supply circuit, it is timely switched to the standby power supply circuit, which can also ensure the power supply continuity of the control unit. At the same time, voltage conversion modules are provided in both the main power supply circuit and the standby power supply circuit. The main voltage conversion module and the standby voltage conversion module respectively convert the voltages of the main power supply and the standby battery to make them adapt to the power supply requirements of the control unit, can flexibly cope with different types of main power supplies and standby batteries, are compatible with multiple voltage inputs, and enhance the adaptability of the power supply circuit to different power supply conditions. At the same time, the two voltage conversion modules make the control voltages output by the main power supply circuit and the standby power supply circuit to the control unit the same, avoiding differences in the power supply voltage caused by the circuit switching process. In addition, during the power supply process of both the main power supply and the standby battery to the control unit, by real-time judging whether the power supply voltage of the power supply circuit is abnormal, measures can be taken in time based on the abnormality. That is to say, the power supply circuit can improve the power supply stability of the control unit of the power electronic device from multiple different angles. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments of the present application or related technologies. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0031] Figure 1 Schematic diagram of a dual - power supply system in an embodiment;

[0032] Figure 2 Schematic diagram of the power supply circuit of the control unit in an embodiment;

[0033] Figure 3 Schematic diagram of the power supply circuit of the control unit in an embodiment;

[0034] Figure 4 Circuit diagram of the power supply circuit of the control unit in an embodiment;

[0035] Figure 5 Schematic diagram of the interface of the control unit in an embodiment.

[0036] Explanation of reference numerals:

[0037] 10: Power supply circuit; 11: Main power supply circuit; 111: Main voltage conversion module; 12: Backup power supply circuit; 121: Backup voltage conversion module; 13: Abnormality detection module; 131: First abnormality detection unit; 1311: Main voltage comparison sub - unit; 1312: Main alarm sub - unit; 132: Second abnormality detection unit; 1321: Backup voltage comparison sub - unit; 1322: Backup alarm sub - unit; 14: Power supply switching module; 141: First switch unit; 142: Second switch unit; 15: Main power switch module; 16: Battery voltage sampling circuit; 17: Battery discharge switch module; 18: Battery charging switch module; 20: Control unit; Detailed implementation manners

[0038] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0039] Before introducing the technical solution of the present application in detail, the background technology of the present application will be briefly introduced.

[0040] The control unit of power electronic equipment plays a decisive role in realizing the intelligent, safe and stable operation of power electronic equipment. If the power supply system of the control unit is unstable, a series of unpredictable faults such as internal state errors, clock inaccuracy, program runaway, hardware damage, data transmission errors and weak anti - interference ability may occur in the control unit, seriously affecting the stability of the operation of the entire electronic equipment. Therefore, the power supply stability of the control unit is the basis for ensuring the intelligent, safe and stable operation of the entire power electronic equipment.

[0041] In the prior art, a single - power - supply system or a dual - power - supply system can be adopted for power supply. However, there are still some deficiencies in the design of these two power - supply system solutions, which are specifically as follows:

[0042] For a single - power - supply system, once the power - supply source has a problem, the control unit will fail, resulting in extremely poor reliability of the control unit. This has a greater impact on systems that require high reliability, such as medical equipment, aerospace, or industrial automation. During the power - supply maintenance or replacement process, it is necessary to turn off the control unit, resulting in a relatively long time when the control unit is in a non - working state, greatly reducing the productivity of the control unit and making power - supply maintenance difficult. The control unit is more sensitive to fluctuations in the input voltage, which will, to a certain extent, reduce the anti - interference ability of the control unit. In addition, due to the limitation of the output power of the single power supply, it may not be able to provide sufficient power to support additional extended components, limiting the scalability of the single - power - supply system.

[0043] For a dual - power - supply system, when the two power - supply systems supply power to the control unit, noise will be generated between the two power - supply systems, interfering with each other and affecting the stability of the control unit. Moreover, there will be differences in the output parameters of the two power supplies, which will also have a certain impact on the stability of the control unit. In severe cases, it may even damage the circuit components of the control unit. The two power - supply systems use the same input power source. When the voltage of the input power source fluctuates abnormally, both power - supply systems will be affected, which will also reduce the anti - interference ability and stability of the control unit.

[0044] Figure 1 As a schematic diagram of the dual - power - supply system, in the figure, the first power supply AC - DC, the first power - supply pass - through and detection circuit, and the first power - supply pass - through and isolation circuit form the first power - supply system, and the second power supply AC - DC, the second power - supply pass - through and detection circuit, and the second power - supply pass - through and isolation circuit form the second power - supply system. Both the first power - supply system and the second power - supply system are powered by the same input power source (220V AC mains input), and both the first power - supply system and the second power - supply system output three - phase DC voltage to the control unit. And the communication interface circuit is connected to the status detection circuit, and the status detection circuit is respectively connected to the first power - supply pass - through and detection circuit and the second power - supply pass - through and detection circuit.

[0045] Therefore, in view of the above problems, the present application provides a power - supply circuit and a power - supply source for a control unit, which can improve the power - supply stability of the control unit of power - electronic devices. Next, the technical solutions of the present application will be introduced in detail.

[0046] In one embodiment, as Figure 2As shown, a power supply circuit 10 for a control unit 20 is provided. The power supply circuit 10 includes: a main power supply circuit 11 of the control unit 20 formed by connecting a main power supply VCC to a main voltage conversion module 111, a backup power supply circuit 12 of the control unit 20 formed by connecting a backup battery BAT to a backup voltage conversion module 121, an abnormality detection module 13, and a power supply switching module 14; the input end of the power supply switching module 14 is respectively connected to the main voltage conversion module 111 and the backup voltage conversion module 121 through the abnormality detection module 13, and the output end of the power supply switching module 14 is connected to the control unit 20;

[0047] The abnormality detection module 13 is configured to detect the abnormal state of the main power supply voltage VCC1 output by the main voltage conversion module 111 when the main power supply VCC supplies power to the control unit 20; and detect the abnormal state of the backup power supply voltage VCC2 output by the backup voltage conversion module 121 when the backup battery BAT supplies power to the control unit 20;

[0048] The power supply switching module 14 is configured to cut off the main power supply circuit 11 of the control unit 20 and at the same time turn on the backup power supply circuit 12 of the control unit 20 to supply power to the control unit 20 through the backup battery BAT when the main power supply voltage VCC1 is abnormal; and cut off both the main power supply circuit 11 and the backup power supply circuit 12 of the control unit 20 when both the main power supply voltage VCC1 and the backup power supply voltage VCC2 are abnormal.

[0049] In the embodiment of the present application, the two power supplies for the control unit 20 are respectively the main power supply circuit 11 and the backup power supply circuit 12. The main power supply circuit 11 obtains the main power supply voltage VCC1 after converting the output voltage of the main power supply VCC through the main voltage conversion module 111. The backup power supply circuit 12 obtains the backup power supply voltage VCC2 after converting the battery voltage of the backup battery BAT through the backup voltage conversion module 121.

[0050] During the actual power supply process, only one power supply circuit 10 can supply power at the same time. That is to say, when the backup power supply circuit 12 is abnormal, the main power supply circuit 11 supplies power to the control unit 20; when the main power supply circuit 11 is abnormal, the backup power supply circuit 12 supplies power to the control unit 20. If both the main power supply circuit 11 and the backup power supply circuit 12 are abnormal, the power supply circuit 10 cannot supply power to the control unit 20.

[0051] It should also be emphasized that the power supply priority of the main power supply circuit 11 is higher than that of the backup power supply circuit 12. That is, when both the main power supply circuit 11 and the backup power supply circuit 12 are normal, the main power supply circuit 11 supplies power to the control unit 20.

[0052] Since the output voltages of the main power supply VCC and the backup power supply are likely to be different, during the power supply process for the control unit 20, if the output voltages of the main power supply VCC and the backup power supply are directly used to supply power to the control unit 20, then there is a difference between the two supply voltages, which will result in poor stability of the control unit 20. Based on this, a main voltage conversion module 111 can be added to the main power supply circuit 11, and a backup voltage conversion module 121 can be added to the backup power supply circuit 12. The voltages of the main power supply VCC and the backup battery BAT are respectively converted by the two voltage conversion modules, so that the output main supply voltage VCC1 and the backup supply voltage VCC2 are the same, thereby improving the stability of the control unit 20 from the perspective of the supply voltage.

[0053] For the main power supply circuit 11, the main power supply VCC therein can use the mains input, and the input voltage can be 220V. At this time, an AC-DC module needs to be set between the main power supply VCC and the main voltage conversion module 111. The main voltage conversion module 111 can be used to convert the output voltage of the main power supply VCC to an appropriate voltage for the control unit 20. It is also possible to rectify and filter the output voltage of the main power supply VCC before conversion and then perform voltage conversion.

[0054] For the backup power supply circuit 12, the backup battery BAT therein can be various types of voltages. For example, the backup battery BAT can be a lead-acid battery, a lithium-ion battery, etc. The backup voltage conversion module 121 can be used to step up or step down the output voltage of the backup battery BAT to an appropriate voltage for the control unit 20.

[0055] Both the main voltage conversion module 111 and the backup voltage conversion module 121 can be DC-DC converters.

[0056] During the power supply process, it is also necessary to use the abnormality detection module 13 to monitor in real time whether the power supply circuit 10 is abnormal. The abnormality detection module 13 can be composed of two voltage sensors and a signal processor. When the main power supply VCC supplies power to the control unit 20, one of the voltage sensors can collect in real time the main supply voltage VCC1 output by the main voltage conversion module 111. After the signal processor amplifies and filters the main supply voltage VCC1, it then determines whether the processed main supply voltage VCC1 is within the normal supply voltage range. If it is, it is determined that the main supply voltage VCC1 output by the main voltage conversion module 111 is not abnormal, and the power supply continues through the main power supply circuit 11; if not, it is determined that the main supply voltage VCC1 output by the main voltage conversion module 111 is abnormal, and the power supply is switched to the backup power supply circuit 12.

[0057] When there is an abnormality in the main power supply circuit 11 and the control unit 20 is powered by the backup battery BAT, another voltage sensor can collect the backup power supply voltage VCC2 output by the backup voltage conversion module 121 in real time. After the signal processor amplifies and filters the backup power supply voltage VCC2, it then determines whether the processed backup power supply voltage VCC2 is within the normal power supply voltage range. If it is, the power supply continues through the backup power supply circuit 12; if not, it is determined that both the main power supply circuit 11 and the backup power supply circuit 12 are abnormal, and the power supply to the control unit 20 is stopped.

[0058] For the power supply switching module 14, it can be composed of two switch units. The first switch unit is used to conduct or cut off the path between the main power supply circuit 11 and the control unit 20, and the second switch unit is used to conduct or cut off the path between the backup power supply circuit 12 and the control unit 20. Then, when both the main power supply circuit 11 and the backup power supply circuit 12 are normal, the main power supply circuit 11 supplies power to the control unit 20, the first switch unit is conducting, and the second switch unit is cut off. When the main power supply circuit 11 is abnormal and the backup power supply circuit 12 is normal, the backup power supply circuit 12 supplies power to the control unit 20, the first switch unit in the power supply switching module 14 switches from the conducting state to the cut-off state, and the second switch unit switches from the cut-off state to the conducting state. When both the main power supply circuit 11 and the backup power supply circuit 12 are abnormal, both the first switch unit and the second switch unit are cut off.

[0059] The power supply circuit 10 of the above-mentioned control unit 20 includes: a main power supply circuit 11 of the control unit 20 formed by connecting the main power supply VCC to the main voltage conversion module 111, a backup power supply circuit 12 of the control unit 20 formed by connecting the backup battery BAT to the backup voltage conversion module 121, an abnormality detection module 13, and a power supply switching module 14; the input end of the power supply switching module 14 is respectively connected to the main voltage conversion module 111 and the backup voltage conversion module 121 through the abnormality detection module 13, and the output end of the power supply switching module 14 is connected to the control unit 20; the abnormality detection module 13 is used to detect the abnormal state of the main power supply voltage VCC1 output by the main voltage conversion module 111 when the main power supply VCC supplies power to the control unit 20; and to detect the abnormal state of the backup power supply voltage VCC2 output by the backup voltage conversion module 121 when the backup battery BAT supplies power to the control unit 20; the power supply switching module 14 is used to cut off the main power supply circuit 11 of the control unit 20 and simultaneously turn on the backup power supply circuit 12 of the control unit 20 when the main power supply voltage VCC1 is abnormal, so as to supply power to the control unit 20 through the backup battery BAT; and to simultaneously cut off the main power supply circuit 11 and the backup power supply circuit 12 of the control unit 20 when both the main power supply voltage VCC1 and the backup power supply voltage VCC2 are abnormal. The power supply circuit 10 of the control unit 20 is provided with a main power supply circuit 11 and a backup power supply circuit 12. The two power supply circuits 10 are respectively the main power supply VCC and the backup battery BAT, and there is no problem of mutual influence during the power supply process. Moreover, the two power supply circuits 10 do not provide power simultaneously, but only one power supply circuit 10 provides power at the same moment. That is, when the main power supply circuit 11 is normal, it supplies power to the control unit 20; when there is an abnormality in the main power supply circuit 11, it is timely switched to the backup power supply circuit 12, which can also ensure the power supply continuity of the control unit 20. At the same time, voltage conversion modules are provided in both the main power supply circuit 11 and the backup power supply circuit 12. The main voltage conversion module 111 and the backup voltage conversion module 121 respectively convert the voltages of the main power supply VCC and the backup battery BAT to make them adapt to the power supply requirements of the control unit 20, can flexibly cope with different types of main power supply VCC and backup battery BAT, are compatible with multiple voltage inputs, and enhance the adaptability of the power supply circuit 10 to different power supply conditions. At the same time, the two voltage conversion modules make the control voltages output by the main power supply circuit 11 and the backup power supply circuit 12 to the control unit 20 consistent, avoiding differences in the power supply voltage caused by the circuit switching process. In addition, during the power supply process of either the main power supply VCC or the backup battery BAT to the control unit 20, by real-time judging whether the power supply voltage of the power supply circuit 10 is abnormal, measures can be taken in a timely manner based on the abnormality. That is to say, the power supply circuit 10 can improve the power supply stability of the control unit 20 of the power electronic device from multiple different perspectives.

[0060] Whether it is for the main power supply circuit 11 or the standby power supply circuit 12, the abnormal detection process is very important. Through abnormal detection, abnormalities in the power supply process can be discovered in a timely manner, so that measures can be taken in a timely manner. Then, in one embodiment, as Figure 3 shown, the specific content of the above-mentioned abnormal detection module 13 will be introduced. The abnormal detection module 13 includes a first abnormal detection unit 131 and a second abnormal detection unit 132. The input end of the first abnormal detection unit 131 is connected to the main voltage conversion module 111, and the input end of the second abnormal detection unit 132 is connected to the standby voltage conversion module 121. The output ends of the first abnormal detection unit 131 and the second abnormal detection unit 132 are both connected to the power supply switching module 14;

[0061] The first abnormal detection unit 131 is used to detect the abnormal state of the main power supply voltage VCC1 and output a first level signal based on the abnormal state;

[0062] The second abnormal detection unit 132 is used to detect the abnormal state of the standby power supply voltage VCC2 and output a second level signal according to the abnormal state;

[0063] The power supply switching module 14 is used to control the conduction and cut-off of the main power supply circuit 11 and the standby power supply circuit 12 according to the first level signal and the second level signal.

[0064] In the embodiment of the present application, in order to respectively perform abnormal detection on the main power supply circuit 11 and the standby power supply circuit 12, the abnormal detection module 13 can be divided into two abnormal detection units, that is, the first abnormal detection unit 131 and the second abnormal detection unit 132. Among them, the first abnormal detection unit 131 is used to connect the main voltage conversion module 111 and the power supply switching module 14, and the second abnormal detection unit 132 is used to connect the standby voltage conversion module 121 and the power supply switching module 14.

[0065] That is to say, the first abnormal detection unit 131 can receive the main power supply voltage VCC1 output from the main voltage conversion module 111, and judge whether the main power supply voltage VCC1 is within the normal power supply voltage range. According to the judgment result, it is determined whether the main power supply voltage VCC1 is in an abnormal state. Then, according to the detection result, a first level signal is output. Specifically, when the main power supply voltage VCC1 is within the normal power supply voltage range, it is determined that the main power supply voltage VCC1 is not abnormal. At this time, the first level signal output is a low level signal; when the main power supply voltage VCC1 is not within the normal power supply voltage range, it is determined that the main power supply voltage VCC1 is in an abnormal state. At this time, the first level signal output is a high level signal.

[0066] Next, a specific example is used to introduce the content of the first anomaly detection unit 131. Continuing to refer to Figure 3 As shown, the first anomaly detection unit 131 includes a main voltage comparison sub-unit 1311 and a main alarm sub-unit 1312. The input end of the main voltage comparison sub-unit 1311 is connected to the main voltage conversion module 111, and the output end of the main voltage comparison sub-unit 1311 is connected to the power supply switching module 14 through the main alarm sub-unit 1312;

[0067] The main voltage comparison sub-unit 1311 is configured to compare the main supply voltage VCC1 with a preset alarm threshold to determine the abnormal state of the main supply voltage VCC1;

[0068] The main alarm sub-unit 1312 is configured to output a high level when the main supply voltage VCC1 is abnormal.

[0069] As Figure 4 shown, the main voltage comparison sub-unit 1311 includes a first resistor R1, a first capacitor C1, and a first integrated power chip U1. The first end of the first resistor R1 and the first end of the first capacitor C1 are both connected to the main voltage conversion module 111. The second end of the first resistor R1 is connected to the first end (VDD) of the first integrated power chip U1. The second end (VOUT) of the first integrated power chip U1 is connected to the main alarm sub-unit 1312, and the second end of the first capacitor C1 and the third end (GND) of the first integrated power chip U1 are grounded.

[0070] The main alarm sub-unit 1312 includes a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a first switching transistor Q1, a second switching transistor Q2, a third switching transistor Q3, a second capacitor C2, and a first voltage regulator diode ZD1. The second end (VOUT) of the first integrated power chip U1 is respectively connected to the first end of the second resistor R2, the first end of the second capacitor C2, and the first end of the third resistor R3. The emitter of the first switching transistor Q1 is respectively connected to the first end of the fourth resistor R4, the first end of the fifth resistor R5, the first end of the eighth resistor R8, and the collector of the second switching transistor Q2. The base of the second switching transistor Q2 is respectively connected to the first end of the sixth resistor R6 and the first end of the seventh resistor R7. The second end of the sixth resistor R6 is connected to the positive electrode of the first voltage regulator diode ZD1. The second end of the eighth resistor R8 is connected to the base of the third switching transistor Q3. The collector of the third switching transistor Q3 is respectively connected to the first end of the ninth resistor R9 and the power supply switching module 14.

[0071] The second terminal of resistor two R2, the second terminal of resistor four R4, the negative electrode of the first voltage regulator ZD1, and the second terminal of resistor nine R9 are connected to the path between the main voltage conversion module 111 and the power supply switching module 14, and the second terminal of the second capacitor C2, the collector of the first switching transistor Q1, the second terminal of resistor five R5, the second terminal of resistor seven R7, the emitter of the second switching transistor Q2, and the emitter of the third switching transistor Q3 are all grounded.

[0072] When the control unit 20 is powered by the main power supply circuit 11, the main power supply voltage VCC1 output by the main voltage conversion module 111 supplies power to the first integrated power chip U1 through the first capacitor C1 and resistor one R1. Since the main voltage conversion module 111 is in a normal working state, the main power supply voltage VCC1 output by it is within the preset warning threshold range of the first integrated power chip U1. Among them, the preset warning threshold range includes the undervoltage warning threshold and the overvoltage protection threshold, that is, the main power supply voltage VCC1 is greater than the undervoltage warning threshold of the first integrated power chip U1 and less than the set overvoltage protection threshold. At this time, the first integrated power chip U1 outputs a high level.

[0073] After the main power supply voltage VCC1 is limited in current and filtered by resistor two R2 and the second capacitor C2, and then the base voltage of the first switching transistor Q1 is pulled up to the same as the main power supply voltage VCC1 through resistor three R3, so that its base voltage is greater than its conduction threshold voltage, and the first switching transistor Q1 remains in the off state. At the same time, because the main power supply voltage VCC1 is less than the overvoltage protection threshold, the first voltage regulator ZD1 does not work, and resistor seven R7 pulls down the base voltage of the second switching transistor Q2, so that its base voltage is less than the conduction threshold voltage of the second switching transistor Q2, and the second switching transistor Q2 also remains in the off state.

[0074] At this time, after the main power supply voltage VCC1 is divided by resistor four R4 and resistor five R5, and then the base voltage of the third switching transistor Q3 is pulled up through resistor eight R8, so that its base voltage is greater than the conduction threshold voltage of the third switching transistor Q3, and the third switching transistor Q3 conducts. At this time, the main alarm sub-unit 1312 outputs a low-level signal.

[0075] When the main voltage conversion module 111 is abnormal, the main supply voltage VCC1 is less than the undervoltage warning threshold of the first integrated power chip U1, and the first integrated power chip U1 outputs a low level. At this time, the base voltage of the first switching transistor Q1 is pulled low through the resistor R3, so that the base voltage of the first switching transistor Q1 is lower than its conduction threshold voltage, and the first switching transistor Q1 conducts. Or when the main supply voltage VCC1 is greater than the overvoltage protection threshold, the first voltage stabilizing diode ZD1 is broken down, and the first voltage stabilizing diode ZD1 starts to work for voltage stabilization. At this time, after the main supply voltage VCC1 is divided and current-limited by the first voltage stabilizing diode ZD1, the resistor R6 and the resistor R7, the base voltage of the second switching transistor Q2 is pulled high, so that the base voltage of the second switching transistor Q2 is greater than the conduction threshold voltage of the second switching transistor Q2, and the second switching transistor Q2 conducts.

[0076] After the first switching transistor Q1 or the second switching transistor Q2 conducts, the base voltage of the third switching transistor Q3 is pulled low through the resistor R8, so that its base voltage is lower than the conduction threshold voltage of the third switching transistor Q3, and the third switching transistor Q3 is turned off. The main alarm sub-unit 1312 outputs a high level. At this time, on the one hand, the control unit 20 can receive this high level, determine that the main voltage conversion module 111 is abnormal, and output a fault alarm prompt. On the other hand, this high level causes the voltage switching module to start working to switch the power supply of the main power supply circuit 11 to the standby power supply circuit 12.

[0077] When the main voltage conversion module 111 returns to normal during the power supply of the standby power supply circuit 12, the main supply voltage VCC1 output by the main voltage conversion module 111 is greater than the undervoltage warning threshold of the first integrated power chip U1 and less than the set overvoltage protection threshold. At this time, the output voltage of the first integrated power chip U1 is converted to a high level. After the main supply voltage VCC1 is current-limited and filtered by the resistor R2 and the second capacitor C2, and then the base voltage of the first switching transistor Q1 is pulled high to the same as the main supply voltage VCC1 through the resistor R3, so that its base voltage is greater than its conduction threshold voltage, and the first switching transistor Q1 is turned off. At the same time, because the main supply voltage VCC1 is less than the overvoltage protection threshold, the first voltage stabilizing diode ZD1 stops working, and the resistor R7 pulls the base voltage of the second switching transistor Q2 low, so that its base voltage is less than the conduction threshold voltage of the second switching transistor Q2, and the second switching transistor Q2 is also turned off.

[0078] After the first switching transistor Q1 and the second switching transistor Q2 are both turned off, the main supply voltage VCC1 is divided and current-limited by resistor four R4 and resistor five R5, and then the base voltage of the third switching transistor Q3 is pulled up through resistor eight R8, making its base voltage greater than the conduction threshold voltage of the third switching transistor Q3, so that the third switching transistor Q3 conducts. After the third switching transistor Q3 conducts, the main fault alarm sub-unit outputs a low level. On the one hand, after receiving the low-level signal, the control unit 20 determines that the main voltage conversion module 111 has returned to normal and eliminates the fault alarm prompt. On the other hand, the low level causes the voltage switching module to act to switch the power supply from the standby power supply circuit 12 to the main power supply circuit 11.

[0079] Similarly, the second abnormality detection unit 132 can receive the standby supply voltage VCC2 output from the standby voltage conversion module 121, and determine whether the standby supply voltage VCC2 is within the normal supply voltage range. According to the determination result, it is determined whether the standby supply voltage VCC2 is in an abnormal state. Then, according to the detection result, a second level signal is output. Specifically, when the standby supply voltage VCC2 is within the normal supply voltage range, it is determined that the standby supply voltage VCC2 is not abnormal. At this time, the second level signal output is a high-level signal; when the standby supply voltage VCC2 is not within the normal supply voltage range, it is determined that the standby supply voltage VCC2 is in an abnormal state. At this time, the second level signal output is a low-level signal.

[0080] The second abnormality detection unit 132 includes a standby voltage comparison sub-unit 1321 and a standby alarm sub-unit 1322. The input end of the standby voltage comparison sub-unit 1321 is connected to the standby voltage conversion module 121, and the output end of the standby voltage comparison sub-unit 1321 is connected to the power supply switching module 14 through the standby alarm sub-unit 1322;

[0081] The standby voltage comparison sub-unit 1321 is used to compare the standby supply voltage VCC2 with a preset alarm threshold to determine the abnormal state of the standby supply voltage VCC2;

[0082] The standby alarm sub-unit 1322 is used to output a low level when the standby supply voltage VCC2 is abnormal.

[0083] Among them, the standby voltage comparison sub-unit 1321 includes a third capacitor C3, a resistor ten R10, and a second integrated power supply chip U2. The first end of the third capacitor C3 and the first end of the resistor ten R10 are connected to the standby voltage conversion module 121. The second end of the resistor ten R10 is connected to the first end (VDD) of the second integrated power supply chip U2. The second end (VOUT) of the second integrated power supply chip U2 is connected to the standby alarm sub-unit 1322, and the second end of the third capacitor C3 and the third end (GND) of the second integrated power supply chip U2 are grounded.

[0084] The standby alarm sub-unit 1322 includes resistor eleven R11, resistor twelve R12, resistor thirteen R13, resistor fourteen R14, resistor fifteen R15, the fourth capacitor C4, the second voltage regulator ZD2, the fourth switching transistor Q4 and the fifth switching transistor Q5. The second terminal (VOUT) of the second integrated power supply chip U2 is respectively connected to the first terminal of resistor eleven R11, the first terminal of resistor twelve R12 and the first terminal of the fourth capacitor C4. The second terminal of resistor twelve R12 is connected to the base of the fourth switching transistor Q4. The emitter of the fourth switching transistor Q4 is respectively connected to the first terminal of resistor fifteen R15 and the collector of the fifth switching transistor Q5. The base of the fifth switching transistor Q5 is respectively connected to the first terminal of resistor thirteen R13 and the first terminal of resistor fourteen R14. The second terminal of resistor thirteen R13 is connected to the positive electrode of the second voltage regulator ZD2.

[0085] The second terminal of resistor eleven R11, the negative electrode of the second voltage regulator ZD2 and the second terminal of resistor fifteen R15 are connected to the path between the standby voltage conversion module 121 and the power supply switching module 14. And the second terminal of the fourth capacitor C4, the collector of the fourth switching transistor Q4, the second terminal of resistor fourteen R14 and the emitter of the fifth switching transistor Q5 are all grounded.

[0086] It should be noted that the first integrated power supply chip U1 in the main voltage comparison sub-unit 1311 and the second integrated power supply chip U2 in the standby voltage comparison sub-unit 1321 are both power management chips. The breakdown voltages of the first voltage regulator ZD1 in the main alarm sub-unit 1312 and the second voltage regulator ZD2 in the standby alarm sub-unit 1322 are the set overvoltage thresholds. The breakdown voltage of the third voltage regulator ZD3 is the maximum allowable charging voltage Vb_max of the standby battery BAT.

[0087] In the normal working state of the main power supply circuit 11, the standby voltage conversion module 121 outputs the standby power supply voltage VCC2. After passing through the third capacitor C3 and resistor ten R10, the standby power supply voltage VCC2 supplies power to the second integrated power supply chip U2. Since the standby voltage conversion module 121 is in the normal working state, the output standby power supply voltage VCC2 is within the preset alarm threshold range of the second integrated power supply chip U2. Among them, the preset alarm threshold range includes the undervoltage alarm threshold and the overvoltage protection threshold, that is, the standby power supply voltage VCC2 is greater than the undervoltage alarm threshold of the second integrated power supply chip U2 and less than the set overvoltage protection threshold. At this time, the second integrated power supply chip U2 outputs a high level.

[0088] After the backup power supply voltage VCC2 is limited in current and filtered by the eleventh resistor R11 and the fourth capacitor C4, the base voltage of the fourth switching transistor Q4 is then raised to the same level as the backup power supply voltage VCC2 through the twelfth resistor R12, making its base voltage greater than its turn-on threshold voltage, and the fourth switching transistor Q4 remains in the off state. At the same time, since the backup power supply voltage VCC2 is less than the overvoltage protection threshold, the second zener diode ZD2 does not work, and the fourteenth resistor R14 pulls down the base voltage of the fifth switching transistor Q5, making its base voltage less than the turn-on threshold voltage of the fifth switching transistor Q5, and the fifth switching transistor Q5 also remains in the off state. At this time, the backup main alarm sub-unit 1312 outputs a high-level signal.

[0089] When the main power supply voltage VCC1 is abnormal and the backup power supply circuit 12 is used for power supply, if the backup voltage conversion module 121 also has an abnormality, the backup power supply voltage VCC2 output by the backup voltage conversion module 121 is less than the undervoltage alarm threshold of the second integrated power supply chip U2, and the second integrated power supply chip U2 outputs a low level. At this time, the base voltage of the fourth switching transistor Q4 is pulled down through the twelfth resistor R12, making the base voltage of the fourth switching transistor Q4 lower than its turn-on threshold voltage, and the fourth switching transistor Q4 conducts. Or the backup power supply voltage VCC2 output by the backup voltage conversion module 121 is greater than the overvoltage protection threshold, the second zener diode ZD2 is broken down, and the second zener diode ZD2 starts to work in voltage regulation. At this time, after the backup power supply voltage VCC2 is divided in voltage and limited in current through the second zener diode ZD2, the thirteenth resistor R13 and the fourteenth resistor R14, the base voltage of the fifth switching transistor Q5 is raised, making the base voltage of the fifth switching transistor Q5 greater than the turn-on threshold voltage of the fifth switching transistor Q5, and the fifth switching transistor Q5 conducts.

[0090] After the fourth switching transistor Q4 or the fifth switching transistor Q5 conducts, the backup fault alarm sub-unit outputs a low level. On the one hand, the control unit 20 can receive the low level, determine that there is a fault in the backup power supply circuit 12, and immediately start the software protection mechanism to turn off the control of the control unit 20 to prevent device damage. On the other hand, the low level can also cause the voltage switching unit to act and cut off the path between the backup voltage conversion module 121 and the control unit 20.

[0091] The above-mentioned anomaly detection module 13 includes a first anomaly detection unit 131 and a second anomaly detection unit 132. The input end of the first anomaly detection unit 131 is connected to the main voltage conversion module 111, and the input end of the second anomaly detection unit 132 is connected to the standby voltage conversion module 121. The output ends of the first anomaly detection unit 131 and the second anomaly detection unit 132 are both connected to the power supply switching module 14. The first anomaly detection unit 131 is used to detect the abnormal state of the main supply voltage VCC1 and output a first level signal based on the abnormal state. The second anomaly detection unit 132 is used to detect the abnormal state of the standby supply voltage VCC2 and output a second level signal according to the abnormal state. The power supply switching module 14 is used to control the conduction and cut-off of the main power supply circuit 11 and the standby power supply circuit 12 according to the first level signal and the second level signal. By respectively monitoring the main supply voltage VCC1 and the standby supply voltage VCC2 in real time through the first anomaly detection unit 131 and the second anomaly detection unit 132, abnormal states such as overvoltage, undervoltage, and voltage fluctuation of the main power supply VCC or the standby power supply can be detected in time. Once an anomaly is detected, the power supply switching module 14 can quickly react according to the corresponding level signal, cut off the abnormal power supply circuit 10, and switch to the normal power supply circuit 10, avoiding abnormal operation of the control unit 20 caused by power supply anomalies and maintaining the stable operation of the control unit 20.

[0092] Next, a detailed introduction to the content of the above-mentioned power supply switching module 14 will be given through an embodiment. Please continue to refer to Figure 3 As shown, the power supply switching module 14 includes a first switch unit 141 and a second switch unit 142. The first switch unit 141 is used to connect the first anomaly detection unit 131 and the control unit 20, and the second switch unit 142 is used to connect the second anomaly detection unit 132 and the control unit 20. Moreover, the second switch unit 142 is also connected to the first anomaly detection unit 131;

[0093] When the first level signal is at a low level, regardless of whether the second level signal is at a high level or a low level, the first switch unit 141 is turned on and the second switch unit 142 is turned off;

[0094] When both the first level signal and the second level signal are at a high level, the first switch unit 141 is turned off and the second switch unit 142 is turned on;

[0095] When the first level signal is at a high level and the second level signal is at a low level, both the first switch unit 141 and the second switch unit 142 are turned off simultaneously.

[0096] In one embodiment, both the first switch unit 141 and the second switch unit 142 are connected to the control unit 20;

[0097] The control unit 20 is configured to control the first switch unit 141 to turn off and the second switch unit 142 to turn on when the main voltage conversion module 111 needs to be disassembled and repaired.

[0098] The first switch unit 141 includes a first diode D1, a second diode D2, a third diode D3, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R20, a resistor R21, a resistor R22, a sixth switch transistor Q6, a seventh switch transistor Q7, and an eighth switch transistor Q8. The positive electrode of the first diode D1 is connected to the control terminal of the control unit 20. The positive electrode of the second diode D2 is respectively connected to the output terminal of the abnormality detection module 13 and the input terminal of the second switch unit 142. The negative electrodes of the first diode D1 and the second diode D2 are both connected to the first end of the resistor R16. The second end of the resistor R16 and the first end of the resistor R17 are both connected to the base of the sixth switch transistor Q6. The collector of the sixth switch transistor Q6 is respectively connected to the first end of the resistor R18, the first end of the resistor R19, and the first end of the resistor R20. The second end of the resistor R20 is connected to the base of the seventh switch transistor Q7. The collector of the seventh switch transistor Q7 is connected to the first end of the resistor R21. The second end of the resistor R21 is respectively connected to the first end of the resistor R22 and the gate of the eighth switch transistor Q8. The second end of the resistor R22 and the drain of the eighth switch transistor Q8 are both connected to the main voltage conversion module 111. The source of the eighth switch transistor Q8 is connected to the positive electrode of the third diode D3. The negative electrode of the third diode D3 is connected to the input terminal of the control unit 20. It can be understood that the main voltage conversion module 111 is connected to the input terminal of the control unit 20 through the eighth switch transistor Q8.

[0099] The second switch unit 142 includes a fourth diode D4, a fifth diode D5, a sixth diode D6, a seventh diode D7, a twenty-third resistor R23, a twenty-fourth resistor R24, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a twenty-seventh resistor R27, a ninth switching transistor Q9 and a tenth switching transistor Q10. The anode of the fourth diode D4 is connected to the main alarm subunit 1312 in the first abnormal detection unit 131. The anode of the fifth diode D5 is connected to the control terminal of the control unit 20. The cathode of the sixth diode D6 is connected to the standby alarm subunit 1322 in the second abnormal detection unit 132. The cathodes of the fourth diode D4 and the fifth diode D5 are both connected to the first end of the twenty-third resistor R23. The second end of the twenty-third resistor R23, the anode of the sixth diode D6, and the first end of the twenty-fourth resistor R24 are all connected to the first end of the twenty-fifth resistor R25. The second end of the twenty-fifth resistor R25 is connected to the base of the ninth switching transistor Q9. The collector of the ninth switching transistor Q9 is connected to the first end of the twenty-sixth resistor R26. The second end of the twenty-sixth resistor R26 is respectively connected to the first end of the twenty-seventh resistor R27 and the gate of the tenth switching transistor Q10. The second end of the twenty-seventh resistor R27 and the drain of the tenth switching transistor Q10 are both connected to the standby voltage conversion module 121. The source of the tenth switching transistor Q10 is connected to the anode of the seventh diode D7. The cathode of the seventh diode D7 is connected to the input terminal of the control unit 20. And the second end of the twenty-fourth resistor R24 and the emitter of the ninth resistor R9 are both grounded. It can be understood that the standby voltage conversion module 121 and the input terminal of the control unit 20 are connected through the tenth switching transistor Q10.

[0100] During the process of the main power supply circuit 11 supplying power to the control unit 20, the main alarm subunit 1312 outputs a low-level signal. At this time, both the second diode D2 and the fourth diode D4 are in the cut-off state. At this time, the base voltage of the sixth switching transistor Q6 is pulled down by the seventeenth resistor R17, making its base voltage lower than the turn-on threshold voltage of the sixth switching transistor Q6, and the sixth switching transistor Q6 remains in the off state. After the main power supply voltage VCC1 is divided and current-limited by the eighteenth resistor R18 and the nineteenth resistor R19, the base voltage of the seventh switching transistor Q7 is then pulled up by the twentieth resistor R20, making its base voltage higher than the turn-on threshold voltage of the seventh switching transistor Q7, and the seventh switching transistor Q7 conducts. After the seventh switching transistor Q7 conducts, the twenty-first resistor R21 is grounded through the seventh switching transistor Q7. After the main power supply voltage VCC1 is divided and current-limited by the twenty-second resistor R22 and the twenty-first resistor R21, the gate voltage of the eighth switching transistor Q8 is pulled down, making its gate-source voltage lower than the turn-on threshold voltage of the eighth switching transistor Q8, and the eighth switching transistor Q8 conducts. After the eighth switching transistor Q8 conducts, the main power supply voltage VCC1 supplies power to the control unit 20 through the eighth switching transistor Q8 and the third diode D3, and the control unit 20 starts to work normally.

[0101] At this time, the standby alarm sub-unit 1322 outputs a high-level signal, the main alarm sub-unit 1312 outputs a low-level signal, and the sixth diode D6 is in the cut-off state. The base voltage of the ninth switching transistor Q9 is pulled low through the twenty-fifth resistor R25 and the twenty-fourth resistor R24, making its base voltage less than its conduction threshold resistance, and the ninth switching transistor Q9 remains in the off state. The standby supply voltage VCC2 pulls up the gate voltage of the tenth switching transistor Q10 through the twenty-seventh resistor R27, making its gate-source voltage greater than its conduction threshold voltage, and the tenth switching transistor Q10 remains in the off state. In this way, it can be ensured that during the operation of the main power supply circuit 11, the main power supply circuit 11 is connected to the control unit 20 through the eighth switching transistor Q8, and the standby power supply circuit 12 is disconnected from the control unit 20 through the tenth switching transistor Q10.

[0102] After an abnormality occurs in the main voltage conversion module 111, the main alarm sub-unit 1312 outputs a high level. At this time, after the high level is voltage-divided and current-limited through the second diode D2, the sixteenth resistor R16, and the seventeenth resistor R17, the base voltage of the sixth switching transistor Q6 is pulled up, making its base voltage greater than the conduction threshold voltage of the sixth switching transistor Q6, and the sixth switching transistor Q6 conducts. After the sixth switching transistor Q6 conducts, the base voltage of the seventh switching transistor Q7 is pulled low through the twentieth resistor R20 and the sixth switching transistor Q6, making its base voltage lower than the conduction threshold voltage of the seventh switching transistor Q7, and the seventh switching transistor Q7 turns off. After the seventh switching transistor Q7 turns off, the main supply voltage VCC1 pulls up the gate voltage of the eighth switching transistor Q8 through the twenty-second resistor R22, making its gate-source voltage higher than the conduction threshold voltage of the eighth switching transistor Q8, and the eighth switching transistor Q8 turns off, and the main supply voltage VCC1 stops supplying power to the control unit 20.

[0103] At the same time, the high level output by the main alarm sub-unit 1312 is voltage-divided through the fourth diode D4, the twenty-third resistor R23, and the twenty-fourth resistor R24, and then the base voltage of the ninth switching transistor Q9 is pulled up through the current-limiting twenty-fifth resistor R25, making its base voltage greater than the conduction threshold voltage of the ninth switching transistor Q9, and the ninth switching transistor Q9 conducts. After the ninth switching transistor Q9 conducts, the twenty-sixth resistor R26 is grounded through the ninth switching transistor Q9. The standby supply voltage VCC2 pulls down the gate voltage of the tenth switching transistor Q10 through the twenty-seventh resistor R27, the twenty-sixth resistor R26, and the ninth switching transistor Q9 for voltage division and current limiting, making its gate-source voltage lower than its conduction threshold voltage, and the tenth switching transistor Q10 turns on. At this time, the standby supply voltage VCC2 starts to supply power to the control unit 20 through the tenth switching transistor Q10 and the seventh diode D7. In this way, when the main voltage conversion module 111 malfunctions, the standby voltage conversion module 121 can be timely switched in to supply power to the control unit 20 to ensure the normal operation of the control unit 20.

[0104] When the backup power supply circuit 12 supplies power, if the main voltage conversion module 111 returns to normal, the main alarm sub-unit 1312 outputs a low level. The second diode D2 and the fourth diode D4 are cut off and conduct. The seventeenth resistor R17 pulls down the base voltage of the sixth switching transistor Q6, and the twenty-fourth resistor R24 pulls down the base voltage of the ninth switching transistor Q9, so that the base voltages of the sixth switching transistor Q6 and the ninth switching transistor Q9 are less than the conduction threshold voltage, and the sixth switching transistor Q6 and the ninth switching transistor Q9 are turned off simultaneously.

[0105] After the ninth switching transistor Q9 is turned off, the backup power supply voltage VCC2 pulls up the gate voltage of the tenth switching transistor Q10 through the twenty-seventh resistor R27, so that its gate-source voltage is greater than its conduction threshold voltage, and the tenth switching transistor Q10 is turned off, and the backup voltage conversion module 121 stops supplying power to the control unit 20. At the same time, after the sixth switching transistor Q6 is turned off, the main power supply voltage VCC1 is divided and current-limited by the eighteenth resistor R18 and the nineteenth resistor R19, and then pulls up the base voltage of the seventh switching transistor Q7 through the twentieth resistor R20, so that its base voltage is higher than the conduction threshold voltage of the seventh switching transistor Q7, and the seventh switching transistor Q7 conducts. After the seventh switching transistor Q7 conducts, the twenty-first resistor R21 is grounded through the seventh switching transistor Q7. The main power supply voltage VCC1 is divided and current-limited by the twenty-second resistor R22 and the twenty-first resistor R21, and pulls down the gate voltage of the eighth switching transistor Q8, so that its gate-source voltage is lower than the conduction threshold voltage of the eighth switching transistor Q8, and the eighth switching transistor Q8 conducts. After the eighth switching transistor Q8 conducts, the main power supply voltage VCC1 supplies power to the control unit 20 again through the eighth switching transistor Q8 and the third diode D3, ensuring the normal operation of the control unit 20.

[0106] If both the main power supply circuit 11 and the backup power supply circuit 12 are abnormal, the backup alarm sub-unit 1322 outputs a low-level signal. The base voltage of the ninth switching transistor Q9 is pulled down through the twenty-fifth resistor R25, the sixth diode D6, and the fifth switching transistor Q5, so that its base voltage is less than the conduction threshold voltage of the ninth switching transistor Q9, and the ninth switching transistor Q9 is turned off. After the ninth switching transistor Q9 is turned off, the backup power supply voltage VCC2 pulls up the gate voltage of the tenth switching transistor Q10 through the twenty-seventh resistor R27, so that its gate-source voltage is greater than its conduction threshold voltage, and the tenth switching transistor Q10 is turned off, and the backup power supply circuit 12 stops supplying power to the control unit 20.

[0107] In addition, it should be noted that when the main voltage conversion module 111 needs to be disassembled and repaired, the control unit 20 sets the control signal M_EN5 of the first diode D1 and the control signal M_EN6 of the fifth diode D5 to high. After the control signal M_EN5 is voltage-divided and current-limited by the first diode D1, the resistor sixteen R16 and the resistor seventeen R17, the base voltage of the sixth switching transistor Q6 is pulled high, making the base voltage greater than the conduction threshold voltage of the sixth switching transistor Q6 to ensure the on state of the sixth switching transistor Q6. The enable control signal M_EN6 is voltage-divided and current-limited by the fifth diode D5, the resistor twenty-three R23 and the resistor twenty-four R24, and then the base voltage of the ninth switching transistor Q9 is pulled high through the resistor twenty-five R25, making the base voltage greater than the conduction threshold voltage of the ninth switching transistor Q9 to ensure the on state of the ninth switching transistor Q9. In this way, the disassembly, repair and installation of the main voltage conversion module 111 can be completed without affecting the operation of the control unit 20.

[0108] The above power supply switching module 14 includes a first switching unit 141 and a second switching unit 142. The first switching unit 141 is used to connect the first abnormal detection unit 131 and the control unit 20, and the second switching unit 142 is used to connect the second abnormal detection unit 132 and the control unit 20, and the second switching unit 142 is also connected to the first abnormal detection unit 131; when the first level signal is low level and the second level signal is high level or low level, the first switching unit 141 is turned on and the second switching unit 142 is turned off; when the first level signal and the second level signal are both high level, the first switching unit 141 is turned off and the second switching unit 142 is turned on; when the first level signal is high level and the second level signal is low level, the first switching unit 141 and the second switching unit 142 are both turned off. By setting the first switching unit 141 and the second switching unit 142 and through the coordinated operation of the two switching units, the power supply switching module 14 can flexibly respond to various state combinations of the main power supply circuit 11 and the standby power supply circuit 12.

[0109] Suppose the main power supply circuit 11 has an abnormality and the standby power supply circuit 12 is used for power supply. At this time, if the main voltage conversion module 111 in the main power supply circuit 11 needs to be disassembled and repaired, then the paths between the main voltage conversion module 111 and the main power supply VCC and between the main voltage conversion module 111 and the control unit 20 need to be disconnected. For the case of disconnecting the path between the main voltage conversion module 111 and the main power supply VCC, a switch needs to be added between the main power supply VCC and the main voltage conversion module 111. Then, in one embodiment, continue to refer to Figure 3As shown, the power supply circuit 10 further includes a main power switch module 15. The main power switch module 15 is used to connect the main power supply VCC and the main voltage conversion module 111, and the controlled end of the main power switch module 15 is connected to the control unit 20;

[0110] The control unit 20 is used to control the main power switch module 15 to disconnect in the case where the main voltage conversion module 111 needs to be disassembled and repaired.

[0111] Among them, the main power switch module 15 includes resistor twenty-eight R28, resistor twenty-nine R29, resistor thirty R30, resistor thirty-one R31, resistor thirty-two R32, resistor thirty-three R33, the eleventh switching tube Q11, the twelfth switching tube Q12, and the thirteenth switching tube Q13. The first end of resistor twenty-eight R28, the first end of resistor thirty-three R33, and the drain of the thirteenth switching tube Q13 are all connected to the main power supply VCC. The second end of resistor twenty-eight R28 is respectively connected to the collector of the eleventh switching tube Q11, the first end of resistor thirty-one R31, and the base of the twelfth switching tube Q12. The base of the eleventh switching tube Q11 is respectively connected to the first end of resistor twenty-nine R29 and the first end of resistor thirty R30. The second end of resistor twenty-nine R29 is connected to the control end of the control unit 20. The collector of the twelfth switching tube Q12 is connected to the first end of resistor thirty-two R32. The second end of resistor thirty-two R32 is respectively connected to the first end of resistor thirty-three R33 and the gate of the thirteenth switching tube Q13. The drain of the thirteenth switching tube Q13 is connected to the main voltage conversion module 111. And the second end of resistor thirty R30, the second end of resistor thirty-one R31, the emitter of the eleventh switching tube Q11, and the emitter of the twelfth switching tube Q12 are all grounded. That is to say, the main power supply VCC is connected to the main voltage conversion module 111 through the thirteenth switching tube Q13.

[0112] When the main voltage conversion module 111 is working normally, after the main power supply VCC is powered on, the output voltage of the main power supply VCC is divided and current-limited by resistor twenty-eight R28 and resistor thirty-one R31, then the base voltage of the twelfth switching tube Q12 is pulled up. The base voltage is greater than the conduction threshold voltage of the twelfth switching tube Q12, and the twelfth switching tube Q12 conducts. Resistor thirty-two R32 is grounded through the twelfth switching tube Q12. The output voltage of the main power supply VCC is divided by resistor thirty-three R33 and resistor thirty-two R32, then the gate voltage of the thirteenth switching tube Q13 is pulled down, making its gate-source voltage less than the conduction threshold voltage of the thirteenth switching tube Q13, and the thirteenth switching tube Q13 conducts. After the thirteenth switching tube Q13 conducts, the main power supply VCC is connected to the main voltage conversion module 111, and the main voltage conversion module 111 starts to work and outputs the main supply voltage VCC1.

[0113] When an abnormal situation occurs in the main voltage conversion module 111 and disassembly and repair are required, the control signal M_EN1 output by the control unit 20 is set high. At this time, after the control signal M_EN1 is divided and current-limited by the twenty-ninth resistor R29 and the thirtieth resistor R30, the base voltage of the eleventh switching transistor Q11 is pulled up, making the base voltage greater than the turn-on threshold voltage of the eleventh switching transistor Q11, and the eleventh switching transistor Q11 is turned on. The base voltage of the twelfth switching transistor Q12 is pulled down, making the base voltage less than the turn-on threshold voltage of the twelfth switching transistor Q12, and the twelfth switching transistor Q12 is turned off. Then, the output voltage of the main power supply VCC passes through the thirty-third resistor R33, pulling up the gate voltage of the thirteenth switching transistor Q13, making the gate-source voltage greater than its turn-on threshold voltage, and the thirteenth switching transistor Q13 is turned off. At this time, the main power supply VCC stops supplying power to the main voltage conversion module 111.

[0114] The above power supply circuit 10 further includes a main power switch module 15. The main power switch module 15 is used to connect the main power supply VCC and the main voltage conversion module 111, and the controlled end of the main power switch module 15 is connected to the control unit 20; the control unit 20 is used to control the main power switch module 15 to disconnect in the case where the main voltage conversion module 111 needs to be disassembled and repaired. By providing the main power switch module 15 between the main power supply VCC and the main voltage conversion module 111, when the main voltage conversion module 111 needs to be disassembled and repaired, the control unit 20 can accurately control the main power switch module 15 to disconnect, completely isolating the main power supply VCC from the main voltage conversion module 111, which can avoid contacting live components during the disassembly and repair process and improve the safety of the repair process.

[0115] For the backup battery BAT, the control unit 20 needs to collect the battery voltage of the backup battery BAT in real time. Then, in one embodiment, continue to refer to Figure 3As shown, the backup power supply circuit 12 further includes a battery voltage sampling circuit 16. The battery voltage sampling circuit 16 includes a third voltage stabilizing diode ZD3, a resistor R34, a resistor R35, a resistor R36, a resistor R37, a resistor R38, a resistor R39, and a fourteenth switching transistor Q14. The negative electrode of the third voltage stabilizing diode ZD3 and the first end of the resistor R34 are both connected to the positive electrode of the backup battery BAT. The second end of the resistor R34 is connected to the battery charging switch module 18. The first end of the resistor R35 is connected to the control terminal of the control unit 20. The second end of the resistor R35 and the first end of the resistor R36 are both connected to the base of the fourteenth switching transistor Q14. The collector of the fourteenth switching transistor Q14 is connected to the first end of the resistor R38. The second end of the resistor R38 is respectively connected to the first end of the resistor R37 and the first end of the resistor R39. The second end of the resistor R37 is respectively connected to the positive electrode of the backup battery BAT and the battery discharge switch module 17. The second end of the resistor R39 outputs the sampled battery voltage of the backup battery BAT.

[0116] Next, the battery discharge switch module 17 and the battery charging switch module 18 will be introduced respectively. In one embodiment, the power supply circuit 10 further includes a battery discharge switch module 17. The battery discharge switch module 17 is used to connect the backup battery BAT and the backup voltage conversion module 121, and the controlled terminal of the battery discharge switch module 17 is connected to the control unit 20;

[0117] The control unit 20 is configured to control the battery discharge switch module 17 to conduct when the backup battery BAT meets the working conditions, so that the backup battery BAT is in a discharging state.

[0118] Among them, the battery discharge switch module 17 includes a resistor R40, a resistor R41, a resistor R42, a resistor R43, a fifteenth switching transistor Q15, and a sixteenth switching transistor Q16. The first end of the resistor R40 and the drain of the sixteenth switching transistor Q16 are respectively connected to the positive electrode of the backup battery BAT. The second end of the resistor R40 and the gate of the sixteenth switching transistor Q16 are both connected to the first end of the resistor R41. The second end of the resistor R41 is connected to the collector of the fifteenth switching transistor Q15. The base of the fifteenth switching transistor Q15 is respectively connected to the first end of the resistor R42 and the first end of the resistor R43. The second end of the resistor R42 is connected to the control terminal of the control unit 20. The second end of the resistor R43 and the emitter of the fifteenth switching transistor Q15 are both grounded. The source of the sixteenth switching transistor Q16 is connected to the backup voltage comparison sub-unit 1321 in the second abnormality detection unit 132.

[0119] After the main power supply circuit 11 supplies power to the control unit 20 and the control unit 20 is in a normal working state, the control signal M_EN3 sent to the resistor thirty-five R35 and the control signal M_EN4 sent to the resistor forty-two R42 are set high. After the enable control signal M_EN3 is divided and current-limited by the resistor thirty-five R35 and the resistor thirty-six R36, the base voltage of the fourteenth switching transistor Q14 is pulled up, making its base voltage greater than the turn-on threshold voltage of the fourteenth switching transistor Q14, and the fourteenth switching transistor Q14 turns on. After the fourteenth switching transistor Q14 turns on, the resistor thirty-eight R38 is grounded through the fourteenth switching transistor Q14. The battery voltage V_BAT of the backup battery BAT is divided by the resistor thirty-seven R37 and the resistor thirty-eight R38, and then a battery voltage sampling signal Vb is generated through the resistor thirty-nine R39, and the battery voltage sampling signal Vb is input to the control unit 20. The control unit 20 can control the battery charge and discharge state according to the battery voltage sampling signal Vb.

[0120] After the control signal M_EN4 is divided and current-limited by the resistor forty-two R42 and the resistor forty-three R43, the base voltage of the fifteenth switching transistor Q15 is pulled up, making its base voltage greater than the turn-on threshold voltage of the fifteenth switching transistor Q15, and the fifteenth switching transistor Q15 turns on. After the fifteenth switching transistor Q15 turns on, the resistor forty-one R41 is grounded through the fifteenth switching transistor Q15. The battery voltage V_BAT is divided and current-limited by the resistor forty R40 and the resistor forty-one R41, pulling down the gate voltage of the sixteenth switching transistor Q16, making its gate voltage less than the turn-on threshold voltage of the sixteenth switching transistor Q16, and the sixteenth switching transistor Q16 turns on. After the sixteenth switching transistor Q16 turns on, the battery voltage V_BAT supplies power to the backup voltage conversion module 121 through the sixteenth switching transistor Q16, and the backup voltage conversion module 121 starts to work and outputs a backup supply voltage VCC2.

[0121] During the normal operation of the control unit 20, the control unit 20 collects the battery voltage of the backup battery BAT in real time through the battery voltage sampling circuit 16. When the battery voltage drops to the set low-voltage charging voltage limit Vb_min, the control unit 20 sets the control signal M_EN2 on the high-resistance forty-six R46. After the control signal M_EN2 is divided and current-limited by the resistor forty-six R46 and the resistor forty-seven R47, the base voltage of the eighteenth switching transistor Q18 is pulled up, making the base voltage greater than the conduction threshold voltage of the triode, and the eighteenth switching transistor Q18 is turned on. After the eighteenth switching transistor Q18 is turned on, the resistor forty-five R45 is grounded through the eighteenth switching transistor Q18. The output voltage of the main power supply VCC is divided by the resistor forty-four R44 and the resistor forty-five R45 to pull down the gate voltage of the seventeenth switching transistor Q17, making the gate-source voltage less than its conduction threshold voltage, and the seventeenth switching transistor Q17 is turned on. After the seventeenth switching transistor Q17 is turned on, the output voltage of the main power supply VCC charges the backup battery BAT through the seventeenth switching transistor Q17 and the resistor thirty-four R34. When the battery voltage of the backup battery BAT rises to the set battery charging upper limit voltage Vb_max, the control unit 20 sets the control signal M_EN2 low. The resistor forty-seven R47 pulls down the base voltage of the eighteenth switching transistor Q18, making the base voltage less than the conduction threshold voltage of the triode, and the eighteenth switching transistor Q18 is turned off. After the eighteenth switching transistor Q18 is turned off, the output voltage of the main power supply VCC pulls up the gate voltage of the seventeenth switching transistor Q17 through the resistor forty-four R44, making the gate-source voltage greater than its conduction threshold voltage, and the seventeenth switching transistor Q17 is turned off, and the backup battery BAT stops charging.

[0122] The above power supply circuit 10 further includes a battery discharge switch module 17. The battery discharge switch module 17 is used to connect the backup battery BAT and the backup voltage conversion module 121, and the controlled end of the battery discharge switch module 17 is connected to the control unit 20; the control unit 20 is used to control the battery discharge switch module 17 to conduct when the backup battery BAT meets the working conditions, so that the backup battery BAT is in a discharging state. By monitoring the battery voltage of the backup battery BAT, the control unit 20 can accurately judge whether the backup battery BAT is available. In the available state, by controlling the conduction of the battery discharge switch module 17, the discharge of the backup battery BAT can be accurately controlled.

[0123] In one embodiment, the power supply circuit 10 further includes a battery charging switch module 18. The battery charging switch module 18 is used to connect the main power supply VCC and the backup battery BAT, and the controlled end of the battery charging switch module 18 is connected to the control unit 20;

[0124] The control unit 20 is configured to control the battery charging switch module 18 to turn on when the main power supply VCC is powered and the backup battery BAT does not meet the working conditions, so that the main power supply VCC charges the backup battery BAT; and to control the battery charging switch module 18 to turn off when the backup battery BAT is fully charged.

[0125] Among them, the battery charging switch module 18 includes a resistor R44, a resistor R45, a resistor R46, a resistor R47, a seventeenth switching transistor Q17 and an eighteenth switching transistor Q18. The first end of the resistor R44 and the drain of the seventeenth switching transistor Q17 are both connected to the main power supply VCC, and the source of the seventeenth switching transistor Q17 is connected to the second end of the resistor R34. The second end of the resistor R44 and the gate of the seventeenth switching transistor Q17 are both connected to the first end of the resistor R45, the second end of the resistor R45 is connected to the collector of the eighteenth switching transistor Q18, the base of the eighteenth switching transistor Q18 is connected to the first ends of the resistor R46 and the resistor R47, and the second end of the resistor R46 is connected to the control terminal of the control unit 20. Also, the second end of the resistor R47 and the emitter of the eighteenth switching transistor Q18 are both grounded.

[0126] The above power supply circuit 10 further includes a battery charging switch module 18. The battery charging switch module 18 is used to connect the main power supply VCC and the backup battery BAT, and the controlled terminal of the battery charging switch module 18 is connected to the control unit 20; the control unit 20 is configured to control the battery charging switch module 18 to turn on when the main power supply VCC is powered and the backup battery BAT does not meet the working conditions, so that the main power supply VCC charges the backup battery BAT; and to control the battery charging switch module 18 to turn off when the backup battery BAT is fully charged. The control unit 20 can collect the battery voltage of the backup battery BAT when the main power supply VCC is powered, can control the battery charging switch module 18 to turn on when the voltage of the backup battery BAT is small, and can accurately control the charging process of the backup battery BAT.

[0127] As can be seen from the above embodiments, the control unit 20 includes an input terminal and a control terminal. Figure 5It is a schematic diagram of the control unit 20. The input terminal interface of the control unit 20 is VCC, and the control terminal interface is the IO interface. As can be seen from the figure, the VCC interface is connected to the power supply circuit 10, and the voltage input to the VCC interface is VCC_O. The IO interface is respectively connected to the second terminal of the resistor R29 (resistor twenty-nine) in the main power switch module 15, the second terminal of the resistor R46 (resistor forty-six) in the battery charging switch module 18, the second terminal of the resistor R35 (resistor thirty-five) in the battery voltage sampling circuit 16, the second terminal of the resistor R42 (resistor forty-two) in the battery discharge switch module 17, the positive electrode of the first diode D1 in the first switch unit 141, the positive electrode of the fifth diode D5 in the second switch unit 142, the battery voltage Vb collected by the battery voltage sampling module, the first level signal M_FAult1 output by the first abnormality detection unit, and the second level signal M_FAult2 output by the second abnormality detection unit. The control unit 20 outputs the first control signal M_EN1 to the second terminal of the resistor R29 in the main power switch module 15, the second control signal M_EN2 to the second terminal of the resistor R46 in the battery charging switch module 18, the third control signal M_EN3 to the second terminal of the resistor R35 in the battery voltage sampling circuit 16, the fourth control signal M_EN4 to the second terminal of the resistor R42 in the battery discharge switch module 17, the fifth control signal M_EN5 to the positive electrode of the first diode D1 in the first switch unit 141, and the sixth control signal M_EN6 to the positive electrode of the fifth diode D5 in the second switch unit 142 through the IO interface.

[0128] Next, a specific embodiment is used to detail the power supply process of the power supply circuit 10 to the control unit 20.

[0129] Before the main power supply VCC is powered on, all MOS transistors and triodes in the power supply circuit 10 are in the off state. During the power-on process of the main power supply VCC, the control unit 20 is in the off state, and the control signals M_EN1, M_EN2, M_EN3, M_EN4, M_EN5, and M_EN6 are all low levels.

[0130] After the main power supply VCC is powered on, the thirteenth switch transistor Q13 conducts, the main power supply VCC is connected to the main voltage conversion module 111, and the main voltage conversion module 111 outputs the main power supply voltage VCC1. When the main power supply voltage VCC1 can work normally, the main alarm sub-unit 1312 outputs a low-level signal, and the eighth switch transistor Q8 between the standby voltage conversion module 121 and the control unit 20 conducts. At this time, the main power supply voltage VCC1 supplies power to the control unit 20.

[0131] After the control unit 20 works normally, it can detect the battery voltage of the backup battery BAT. If the battery voltage is small, the seventeenth switching transistor Q17 is controlled to conduct. While the main power supply VCC supplies power to the control unit 20, it can also charge the backup battery BAT. After being fully charged, the seventeenth switching transistor Q17 is then turned off. If the battery voltage is normal, the sixteenth switching transistor Q16 conducts, and the backup voltage conversion module 121 outputs the backup voltage to charge the second integrated voltage chip. The tenth switching transistor Q10 between the backup voltage conversion module 121 and the control unit 20 is turned off.

[0132] If the main power supply voltage VCC1 is abnormal, the main alarm sub-unit 1312 outputs a high-level signal, and the eighth switching transistor Q8 between the backup voltage conversion module 121 and the control unit 20 is turned off. At the same time, the tenth switching transistor Q10 between the backup voltage conversion module 121 and the control unit 20 conducts, and the backup power supply voltage VCC2 supplies power to the control unit 20 through the tenth switching transistor Q10. If it is necessary to disassemble and repair the main voltage conversion module 111 in the main power supply circuit 11, the control unit 20 controls the thirteenth switching transistor Q13 and the eighth switching transistor Q8 to be both turned off.

[0133] When the backup voltage output by the backup voltage conversion module 121 supplies power, if the backup voltage is also abnormal, at this time, both the eighth switching transistor Q8 and the tenth switching transistor Q10 are turned off, and the control unit 20 starts the software protection mechanism to turn off all functions.

[0134] When the backup voltage output by the backup voltage conversion module 121 supplies power and the main power supply voltage VCC1 returns to normal, the eighth switching transistor Q8 is turned on, and the power supply continues through the main power supply voltage VCC1. At the same time, the tenth switching transistor Q10 is turned off. That is to say, the power supply priority of the main power supply voltage VCC1 is higher than that of the backup power supply voltage VCC2.

[0135] In one embodiment, a power supply is also provided, and this power supply includes the content of any one of the embodiments of the power supply circuit 10 of the above control unit 20.

[0136] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as these combinations of technical features do not conflict, they should all be considered to be within the scope recorded in this application.

[0137] The above embodiments only illustrate several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several variations and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A power supply circuit for a control unit, characterized in that, The power supply circuit includes: a main power supply circuit of the control unit formed by connecting the main power supply and the main voltage conversion module, a backup power supply circuit of the control unit formed by connecting the backup battery and the backup voltage conversion module, an abnormality detection module, and a power supply switching module; the input end of the power supply switching module is respectively connected to the main voltage conversion module and the backup voltage conversion module through the abnormality detection module, and the output end of the power supply switching module is connected to the control unit; The abnormality detection module is configured to detect the abnormal state of the main power supply voltage output by the main voltage conversion module when the main power supply supplies power to the control unit; and detect the abnormal state of the backup power supply voltage output by the backup voltage conversion module when the backup battery supplies power to the control unit; The power supply switching module is configured to cut off the main power supply circuit of the control unit and simultaneously turn on the backup power supply circuit of the control unit to supply power to the control unit through the backup battery when the main power supply voltage is abnormal; and cut off both the main power supply circuit and the backup power supply circuit of the control unit when both the main power supply voltage and the backup power supply voltage are abnormal.

2. The circuit according to claim 1, wherein The abnormality detection module includes a first abnormality detection unit and a second abnormality detection unit. The input end of the first abnormality detection unit is connected to the main voltage conversion module, the input end of the second abnormality detection unit is connected to the backup voltage conversion module, and the output ends of the first abnormality detection unit and the second abnormality detection unit are both connected to the power supply switching module; The first abnormality detection unit is configured to detect the abnormal state of the main power supply voltage and output a first level signal based on the abnormal state; The second abnormality detection unit is configured to detect the abnormal state of the backup power supply voltage and output a second level signal according to the abnormal state; The power supply switching module is configured to control the conduction and cut-off of the main power supply circuit and the backup power supply circuit according to the first level signal and the second level signal.

3. The circuit according to claim 2, wherein The first abnormality detection unit includes a main voltage comparison sub-unit and a main alarm sub-unit. The input end of the main voltage comparison sub-unit is connected to the main voltage conversion module, and the output end of the main voltage comparison sub-unit is connected to the power supply switching module through the main alarm sub-unit; The main voltage comparison sub-unit is configured to compare the main power supply voltage with a preset alarm threshold to determine the abnormal state of the main power supply voltage; The main alarm sub-unit is configured to output a high level when the main power supply voltage is abnormal.

4. The circuit according to claim 2, wherein The second abnormality detection unit includes a backup voltage comparison sub-unit and a backup alarm sub-unit. The input end of the backup voltage comparison sub-unit is connected to the backup voltage conversion module, and the output end of the backup voltage comparison sub-unit is connected to the power supply switching module through the backup alarm sub-unit; The backup voltage comparison sub-unit is configured to compare the backup power supply voltage with a preset alarm threshold to determine the abnormal state of the backup power supply voltage; The standby alarm sub-unit is used to output a low level when the standby power supply voltage is abnormal.

5. The circuit according to any one of claims 2-4, characterized in that, The power supply switching module includes a first switch unit and a second switch unit. The first switch unit is used to connect the first abnormality detection unit and the control unit. The second switch unit is used to connect the second abnormality detection unit and the control unit, and the second switch unit is also connected to the first abnormality detection unit; When the first level signal is at a low level and the second level signal is at a high level or a low level, turn on the first switch unit and turn off the second switch unit; when the first level signal and the second level signal are both at a high level, turn off the first switch unit and turn on the second switch unit; when the first level signal is at a high level and the second level signal is at a low level, turn off both the first switch unit and the second switch unit simultaneously.

6. The circuit according to claim 5, wherein Both the first switch unit and the second switch unit are connected to the control unit; The control unit is used to control the first switch unit to turn off and the second switch unit to turn on when the main voltage conversion module needs to be disassembled for repair.

7. The circuit according to any one of claims 1-4, characterized in that, The power supply circuit further includes a main power switch module, which is used to connect the main power supply and the main voltage conversion module, and the controlled end of the main power switch module is connected to the control unit; The control unit is used to control the main power switch module to disconnect when the main voltage conversion module needs to be disassembled for repair.

8. The circuit according to any one of claims 1 to 4, characterized in that, The power supply circuit further includes a battery discharge switch module, which is used to connect the standby battery and the standby voltage conversion module, and the controlled end of the battery discharge switch module is connected to the control unit; The control unit is used to control the battery discharge switch module to turn on when the standby battery meets the working conditions, so that the standby battery is in a discharging state.

9. The circuit according to any one of claims 1-4, characterized in that, The power supply circuit further includes a battery charging switch module, which is used to connect the main power supply and the standby battery, and the controlled end of the battery charging switch module is connected to the control unit; The control unit is used to control the battery charging switch module to turn on when the main power supply is supplying power and the standby battery does not meet the working conditions, so that the main power supply charges the standby battery; and to control the battery charging switch module to turn off when the standby battery is fully charged.

10. A power supply, characterized in that, The power supply includes the power supply circuit of the control unit according to any one of claims 1-9 above.

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