Relay sticking fault detection circuit

Abstract

The utility model discloses a relay sticking fault detection circuit. The detection circuit comprises a first relay, a second relay, a first voltage detection module, a second voltage detection module and a control module. The first relay is arranged on a live wire of a commercial power grid, and the second relay is arranged on a null line of the commercial power grid; the first voltage detection module is used for outputting a first detection voltage to the control module; the control module is used for judging whether the first relay has a sticking fault or not; the second voltage detection module is used for outputting a second detection voltage to the control module; and the control module is used for judging whether the second relay has a sticking fault. According to the utility model, whether the relay in the commercial power input line is stuck or not can be effectively detected.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic technical field especially relates to a relay sticking failure detection circuit. BACKGROUND

[0002] In the mains input line of current uninterruptible power supply (UPS) and inverter and other equipment, a relay is an indispensable component, and at the same time, the relay has a very high reliability requirement. If the relay appears sticking failure, it has a great influence and harm on the function of UPS and inverter and other equipment, and also has user personal safety hidden danger. Therefore, the sticking detection of the relay is very important. CONTENT OF UTILITY MODEL

[0003] The utility model provides a relay sticking failure detection circuit to realize the detection of relay sticking failure.

[0004] In the first aspect, the utility model provides a relay sticking failure detection circuit, and the detection circuit includes: first relay, second relay, first voltage detection module, second voltage detection module and control module.

[0005] The first relay is arranged on the live wire of the mains power grid, and the second relay is arranged on the zero line of the mains power grid; the first input end of the first voltage detection module is connected with the live wire at the rear end of the first relay, and the second input end of the first voltage detection module is connected with the zero line at the front end of the second relay; the output end of the first voltage detection module is connected with the control module; the first input end of the second voltage detection module is connected with the live wire at the front end of the first relay, and the second input end of the second voltage detection module is connected with the zero line at the rear end of the second relay; the output end of the second voltage detection module is connected with the control module.

[0006] The first voltage detection module is used for outputting first detection voltage to the control module, and the control module is used for judging whether the first relay has sticking failure or not.

[0007] The second voltage detection module is used for outputting second detection voltage to the control module, and the control module is used for judging whether the second relay has sticking failure or not.

[0008] Optionally, the detection circuit further includes: reference voltage generation module.

[0009] The first input end of the reference voltage generation module is connected with the live wire at the front end of the first relay, the second input end of the reference voltage generation module is connected with the zero line at the front end of the second relay, the reference voltage generation module is connected with the mains voltage provided by the mains power grid, and the output end of the reference voltage generation module is connected with the control module.

[0010] The reference voltage generation module is configured to output a reference voltage to the control module according to a mains voltage, and the control module is configured to determine whether the first relay has a sticking failure according to the reference voltage and a first detection voltage, and to determine whether the second relay has a sticking failure according to the reference voltage and a second detection voltage.

[0011] Optionally, the detection circuit further comprises a first relay control module and a second relay control module.

[0012] The first relay control module is connected with the first relay and the control module, and the second relay control module is connected with the second relay and the control module.

[0013] The first relay control module is configured to control the first relay to close or open according to a first control signal sent by the control module, and the second relay control module is configured to control the second relay to close or open according to a second control signal sent by the control module.

[0014] Optionally, the first voltage detection module comprises a first operational amplifier circuit, and the second voltage detection module comprises a second operational amplifier circuit.

[0015] The first input end of the first operational amplifier circuit is connected with a live wire at the rear end of the first relay, and the second input end of the first operational amplifier circuit is connected with a zero line at the front end of the second relay; the output end of the first operational amplifier circuit is connected with the control module; the first operational amplifier circuit is configured to input a first input voltage provided by the live wire at the rear end of the first relay and the zero line at the front end of the second relay, and output a first detection voltage to the control module after reducing the first input voltage according to a first proportion.

[0016] The first input end of the second operational amplifier circuit is connected with the live wire at the front end of the first relay, and the second input end of the second operational amplifier circuit is connected with the zero line at the rear end of the second relay; the output end of the second operational amplifier circuit is connected with the control module; the second operational amplifier circuit is configured to input a second input voltage provided by the live wire at the front end of the first relay and the zero line at the rear end of the second relay, and output a second detection voltage to the control module after reducing the second input voltage according to a second proportion.

[0017] Optionally, the first operational amplifier circuit comprises a first operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor.

[0018] The first end of the first resistor is connected with the live wire at the rear end of the first relay, and the second end of the first resistor is connected with the non-inverting input end of the first operational amplifier; the first end of the second resistor is connected with the zero line at the front end of the second relay, and the second end of the second resistor is connected with the inverting input end of the first operational amplifier.

[0019] The third resistor is connected between the non-inverting input terminal and the output terminal of the first operational amplifier, and the fourth resistor is connected between the inverting input terminal of the first operational amplifier and the ground; the fifth resistor is connected between the output terminal of the first operational amplifier and the control module, and the sixth resistor is connected between the control module and the first power supply.

[0020] Optionally, the second operational amplifier circuit comprises a second operational amplifier, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor and a twelfth resistor.

[0021] The first end of the seventh resistor is connected with the live wire of the front end of the first relay, and the second end of the seventh resistor is connected with the non-inverting input terminal of the second operational amplifier; the first end of the eighth resistor is connected with the zero line of the rear end of the second relay, and the second end of the eighth resistor is connected with the inverting input terminal of the second operational amplifier.

[0022] The ninth resistor is connected between the non-inverting input terminal and the output terminal of the second operational amplifier, and the tenth resistor is connected between the inverting input terminal of the second operational amplifier and the ground; the eleventh resistor is connected between the output terminal of the second operational amplifier and the control module, and the twelfth resistor is connected between the control module and the first power supply.

[0023] Optionally, the reference voltage generation module comprises a third operational amplifier circuit.

[0024] The first input terminal of the third operational amplifier circuit is connected with the live wire of the front end of the first relay, the second input terminal of the third operational amplifier circuit is connected with the zero line of the front end of the second relay, the third operational amplifier circuit is connected with the commercial voltage provided by the commercial power grid, and the output terminal of the third operational amplifier circuit is connected with the control module.

[0025] The third operational amplifier circuit is configured to output the reference voltage to the control module after reducing the commercial voltage by a third proportion.

[0026] Optionally, the third operational amplifier circuit comprises a third operational amplifier, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor and an eighteenth resistor.

[0027] The first end of the thirteenth resistor is connected with the live wire of the front end of the first relay, and the second end of the thirteenth resistor is connected with the non-inverting input terminal of the third operational amplifier; the first end of the fourteenth resistor is connected with the zero line of the front end of the second relay, and the second end of the fourteenth resistor is connected with the inverting input terminal of the third operational amplifier.

[0028] The fifteenth resistor is connected between the non-inverting input terminal and the output terminal of the third operational amplifier, and the sixteenth resistor is connected between the inverting input terminal of the third operational amplifier and the ground; the seventeenth resistor is connected between the output terminal of the third operational amplifier and the control module, and the eighteenth resistor is connected between the control module and the first power supply.

[0029] Optionally, the first relay control module comprises a nineteenth resistor and a first transistor;

[0030] The first relay comprises a first coil and a first contact, the first contact is arranged on a live wire, a first end of the first coil is connected with the second power supply, a second end of the first coil is connected with a first end of the first transistor, and a second end of the first transistor is grounded;

[0031] A first end of the nineteenth resistor is connected with the control module, and a second end of the nineteenth resistor is connected with a control end of the first transistor.

[0032] Optionally, the second relay control module comprises a twentieth resistor and a second transistor;

[0033] The second relay comprises a second coil and a second contact, the second contact is arranged on a zero wire, a first end of the second coil is connected with the second power supply, a second end of the second coil is connected with a first end of the second transistor, and a second end of the second transistor is grounded;

[0034] A first end of the twentieth resistor is connected with the control module, and a second end of the twentieth resistor is connected with a control end of the second transistor.

[0035] The technical scheme of the embodiment of the utility model, set up first voltage detection module input first relay back end's live wire and second relay front end's zero line provide first input voltage, and output first detection voltage to control module after processing first input voltage. The control module calculates the first input voltage according to the first detection voltage. Set up second voltage detection module input first relay front end's live wire and second relay back end's zero line provide second input voltage, and output second detection voltage to control module after processing second input voltage. The control module calculates the second input voltage according to the second detection voltage. The control module respectively when first relay is closed and open state, according to the value of the first input voltage calculated judges whether first relay occurs stick dead failure, when second relay is closed and open state, according to the value of the second input voltage calculated judges whether second relay occurs stick dead failure. The control module can trigger alarm device alarm when first relay and / or second relay occurs stick dead failure. The technical scheme of the embodiment of the utility model, can effectively detect whether the relay in the input line of commercial power occurs stick dead failure, and remind the user through alarm device that the relay in the input line of current load equipment fails, can promptly investigate the problem of load equipment, and exclude potential safety risk and hidden danger.

[0036] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the utility model, nor is it used to limit the scope of the utility model. Other features of the utility model will become easy to understand through the following description. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the structure of a relay sticking fault detection circuit provided in an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of another relay sticking fault detection circuit provided in this embodiment of the utility model;

[0040] Figure 3 This is a schematic diagram of another relay sticking fault detection circuit provided in this embodiment of the utility model;

[0041] Figure 4 This is a schematic diagram of another relay sticking fault detection circuit provided in this embodiment of the utility model;

[0042] Figure 5 This is a schematic diagram of another relay sticking fault detection circuit provided in this embodiment of the utility model;

[0043] Figure 6 This is a schematic diagram of another relay sticking fault detection circuit provided in this embodiment of the utility model;

[0044] Figure 7 This is a schematic diagram of another relay sticking fault detection circuit provided in this embodiment of the utility model;

[0045] Figure 8 This is a schematic diagram of another relay sticking fault detection circuit provided in this embodiment of the utility model;

[0046] Figure 9 This is a schematic diagram of another relay sticking fault detection circuit provided in this embodiment of the utility model. Detailed Implementation

[0047] In order to make the person skilled in the art better understand the technical scheme of the present application, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor should belong to the scope of protection of the present application.

[0048] It should be noted that the terms "first", "second" and the like in the description and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to only those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0049] Figure 1 is a structural schematic diagram of a relay sticking fault detection circuit provided by the embodiments of the present application, as shown in Figure 1 The detection circuit includes: a first relay 1, a second relay 2, a first voltage detection module 3, a second voltage detection module 4 and a control module 5. The first relay 1 is arranged on the live wire L of the power grid, and the second relay 2 is arranged on the neutral wire N of the power grid. The first input end of the first voltage detection module 3 is connected with the live wire L at the rear end of the first relay 1, and the second input end of the first voltage detection module 3 is connected with the neutral wire N at the front end of the second relay 2. The output end of the first voltage detection module 3 is connected with the control module 5. The first input end of the second voltage detection module 4 is connected with the live wire L at the front end of the first relay 1, and the second input end of the second voltage detection module 4 is connected with the neutral wire N at the rear end of the second relay 2. The output end of the second voltage detection module 4 is connected with the control module 5. The first voltage detection module 3 is used to output a first detection voltage to the control module 5, and the control module 5 is used to judge whether the first relay 1 has a sticking fault. The second voltage detection module 4 is used to output a second detection voltage to the control module 5, and the control module 5 is used to judge whether the second relay 2 has a sticking fault.

[0050] Specifically, the live wire L and the neutral wire N of the mains power grid are connected to the load 10 through the first relay 1 and the second relay 2 respectively to supply power to the load 10. The live wire in front of the first relay 1 and the neutral wire in front of the second relay 2 provide the mains voltage. The first input end of the first voltage detection module 3 is connected to the live wire L at the rear end of the first relay 1, and the second input end of the first voltage detection module 3 is connected to the neutral wire N at the front end of the second relay 2. The first voltage detection module 3 inputs the first input voltage provided by the live wire L at the rear end of the first relay 1 and the neutral wire N at the front end of the second relay 2, and outputs the first detection voltage to the control module 5 after processing the first input voltage. The first input end of the second voltage detection module 4 is connected to the live wire L in front of the first relay 1, and the second input end of the second voltage detection module 4 is connected to the neutral wire N at the rear end of the second relay 2. The second voltage detection module 4 inputs the second input voltage provided by the live wire L in front of the first relay 1 and the neutral wire N at the rear end of the second relay 2, and outputs the second detection voltage to the control module 5 after processing the second input voltage.

[0051] When it is necessary to detect the stuck fault of the first relay 1, the first relay 1 needs to be controlled to be closed and then opened, or to be opened and then closed. When the first relay 1 is controlled to be in the open state, the control module 5 processes the input first detection voltage to calculate the first input voltage, and when the first relay 1 is controlled to be in the closed state, the control module 5 also processes the input first detection voltage to calculate the first input voltage.

[0052] If the first input voltage calculated by the control module 5 is zero when the first relay 1 is controlled to be in the open state, and the first input voltage calculated by the control module 5 is the same as the mains voltage when the first relay 1 is controlled to be in the closed state, the control module 5 determines that the first relay 1 has no stuck fault.

[0053] If the first input voltage calculated by the control module 5 is the same as the mains voltage when the first relay 1 is controlled to be in the open state, and the first input voltage calculated by the control module 5 is also the same as the mains voltage when the first relay 1 is controlled to be in the closed state, the control module 5 determines that the first relay 1 has a stuck fault, and at this time the control module 5 can determine that the first relay 1 is stuck at the closed end contact, i.e. the first relay 1 is always in the closed state.

[0054] If the first input voltage calculated by the control module 5 is zero when the first relay 1 is controlled to be in the open state, and the first input voltage calculated by the control module 5 is also zero when the first relay 1 is controlled to be in the closed state, the control module 5 determines that the first relay 1 has a stuck fault, and at this time the control module 5 can determine that the first relay 1 is stuck at the open end contact, i.e. the first relay 1 is always in the open state.

[0055] When the second relay 2 needs to be detected for sticking failure, the second relay 2 needs to be controlled to be closed and then opened, or to be opened and then closed. When the second relay 2 is controlled to be in the open state, the control module 5 processes the input second detection voltage to calculate the second input voltage, and when the second relay 2 is controlled to be in the closed state, the control module 5 also processes the input second detection voltage to calculate the second input voltage.

[0056] If the second input voltage calculated by the control module 5 when the second relay 2 is controlled to be in the open state is zero, and the second input voltage calculated by the control module 5 when the second relay 2 is controlled to be in the closed state is the same as the mains voltage, the control module 5 determines that the second relay 2 does not have a sticking failure.

[0057] If the second input voltage calculated by the control module 5 when the second relay 2 is controlled to be in the open state is the same as the mains voltage, and the second input voltage calculated by the control module 5 when the second relay 2 is controlled to be in the closed state is also the same as the mains voltage, the control module 5 determines that the second relay 2 has a sticking failure, and at this time the control module 5 can determine that the second relay 2 is stuck at the closed end contact, that is, the second relay 2 is always in the closed state.

[0058] If the second input voltage calculated by the control module 5 when the second relay 2 is controlled to be in the open state is zero, and the second input voltage calculated by the control module 5 when the second relay 2 is controlled to be in the closed state is also zero, the control module 5 determines that the second relay 2 has a sticking failure, and at this time the control module 5 can determine that the second relay 2 is stuck at the open end contact, that is, the second relay 2 is always in the open state.

[0059] The control module 5 can also be connected with an alarm device, and when the control module 5 detects that the first relay 1 and / or the second relay 2 has a sticking failure, the control module 5 controls the alarm device to alarm, so as to remind the user that the first relay 1 and / or the second relay 2 in the input line of the load device has a failure, and the problem of the load device can be checked in time, and potential safety risks and hidden dangers can be eliminated.

[0060] The technical scheme of the embodiment of the utility model discloses, set up the first voltage detection module input the first input voltage that the live wire of first relay rear end and the zero line of second relay front end provide, and export the first detection voltage to the control module after processing the first input voltage. The control module calculates the first input voltage according to the first detection voltage. Set up the second voltage detection module input the second input voltage that the live wire of first relay front end and the zero line of second relay rear end provide, and export the second detection voltage to the control module after processing the second input voltage. The control module calculates the second input voltage according to the second detection voltage. The control module judges whether the first relay occurs stick dead failure according to the value of the first input voltage calculated when the first relay is closed and disconnected, judges whether the second relay occurs stick dead failure according to the value of the second input voltage calculated when the second relay is closed and disconnected. The control module can trigger the alarm device to alarm when the first relay and / or the second relay occurs stick dead failure. The technical scheme of the embodiment of the utility model discloses can effectively detect whether the relay in the input line of commercial power occurs stick dead failure, and reminds the user that the relay in the input line of current load equipment appears failure through the alarm device, can promptly investigate the problem of load equipment, and excludes potential security risk and hidden danger.

[0061] Optionally, on the basis of each of the above embodiments, Figure 2 It is another structure schematic view of relay stick dead failure detection circuit provided by the embodiment of the utility model, as Figure 2 As shown, the detection circuit further comprises: a reference voltage generation module 6. The first input end of the reference voltage generation module 6 is connected with the live wire L at the front end of the first relay 1, the second input end of the reference voltage generation module 6 is connected with the zero line N at the front end of the second relay 2, the reference voltage generation module 6 is connected with the commercial voltage provided by the commercial power grid, and the output end of the reference voltage generation module 6 is connected with the control module 5. The reference voltage generation module 6 is used for outputting the reference voltage to the control module 5 according to the commercial voltage, and the control module 5 is used for judging whether the first relay 1 occurs stick dead failure according to the reference voltage and the first detection voltage. The control module 5 is also used for judging whether the second relay 2 occurs stick dead failure according to the reference voltage and the second detection voltage.

[0062] Specifically, the relay stick dead failure detection circuit can further comprise a reference voltage generation module 6, the first input end and the second input end of the reference voltage generation module 6 are connected to the live wire L at the front end of the first relay 1 and the zero line N at the front end of the second relay 2 respectively, and the commercial voltage provided by the live wire L at the front end of the first relay 1 and the zero line N at the front end of the second relay 2 is input. The reference voltage generation module 6 outputs the reference voltage to the control module 5 after processing the commercial voltage, and the control module 5 calculates the commercial voltage according to the input reference voltage.

[0063] The control module 5 obtains the mains voltage through the reference voltage generation module 6, and when the first relay 1 is controlled to be in the open state, if the first input voltage calculated by the control module 5 is zero, and when the first relay 1 is controlled to be in the closed state, the first input voltage calculated by the control module 5 is the same as the calculated mains voltage, the control module 5 determines that the first relay 1 does not have a sticking fault.

[0064] If the first input voltage calculated by the control module 5 is the same as the calculated mains voltage when the first relay 1 is controlled to be in the open state, and the first input voltage calculated by the control module 5 is also the same as the calculated mains voltage when the first relay 1 is controlled to be in the closed state, the control module 5 determines that the first relay 1 has a sticking fault, and at this time the control module 5 can determine that the first relay 1 is stuck at the closed end contact, that is, the first relay 1 is always in the closed state.

[0065] Optionally, based on the above embodiments, Figure 3 is another structural schematic diagram of a relay sticking fault detection circuit provided by the embodiment of the utility model, as Figure 3 shown, the detection circuit further comprises: a first relay control module 7 and a second relay control module 8. The first relay control module 7 is connected with the first relay 1 and the control module 5, and the second relay control module 8 is connected with the second relay 2 and the control module 5. The first relay control module 7 is used to control the first relay 1 to be closed or opened according to the first control signal sent by the control module 5. The second relay control module 8 is used to control the second relay 2 to be closed or opened according to the second control signal sent by the control module 5.

[0066] Specifically, when the first relay 1 needs to be detected for a sticking fault, the first relay 1 needs to be controlled to be closed and then opened, or to be opened and then closed. The control module 5 sends a first control signal to the first relay control module 7, and the first relay control module 7 can control the first relay 1 to be closed or opened according to the level state of the first control signal. For example, when the first control signal is a low-level signal, the first relay control module 7 controls the first relay 1 to be opened, and when the first control signal is a high-level signal, the first relay control module 7 controls the first relay 1 to be closed.

[0067] When the second relay 2 needs to be detected for the stuck fault, the second relay 2 needs to be controlled to be closed and then opened, or to be opened and then closed. The control module 5 sends a second control signal to the second relay control module 8, and the second relay control module 8 can control the second relay 2 to be closed or opened according to the level state of the second control signal. For example, when the second control signal is a low-level signal, the second relay control module 8 controls the second relay 2 to be opened, and when the second control signal is a high-level signal, the second relay control module 8 controls the second relay 2 to be closed.

[0068] Optionally, based on the above embodiments, Figure 4 is another structure schematic diagram of a relay stuck fault detection circuit provided by the embodiment of the utility model, as Figure 4 shown, the first voltage detection module 3 includes a first operational amplifier circuit 31. The second voltage detection module 4 includes a second operational amplifier circuit 41.

[0069] The first input end of the first operational amplifier circuit 31 is connected with the firewire L at the rear end of the first relay 1, and the second input end of the first operational amplifier circuit 31 is connected with the zero line N at the front end of the second relay 2. The output end of the first operational amplifier circuit 31 is connected with the control module 5. The first operational amplifier circuit 31 is used for connecting the first input voltage provided by the firewire L at the rear end of the first relay 1 and the zero line N at the front end of the second relay 2, reducing the first input voltage according to the first proportion, and outputting the first detection voltage to the control module 5. The first input end of the second operational amplifier circuit 41 is connected with the firewire L at the front end of the first relay 1, and the second input end of the second operational amplifier circuit 41 is connected with the zero line N at the rear end of the second relay 2. The output end of the second operational amplifier circuit 41 is connected with the control module 5. The second operational amplifier circuit 41 is used for connecting the second input voltage provided by the firewire L at the front end of the first relay 1 and the zero line N at the rear end of the second relay 2, reducing the second input voltage according to the second proportion, and outputting the second detection voltage to the control module 5.

[0070] Specifically, the first voltage detection module 3 can include the first operational amplifier circuit 31, the first input end of the first operational amplifier circuit 31 is connected with the firewire L at the rear end of the first relay 1, the second input end of the first operational amplifier circuit 31 is connected with the zero line N at the front end of the second relay 2, the first operational amplifier circuit 31 inputs the first input voltage, and reduces and processes the first input voltage according to the first proportion, and then outputs the first detection voltage to the control module 5. In this way, the first detection voltage outputted from the first voltage detection module 3 to the control module 5 meets the voltage range of the signal processed by the control module 5.

[0071] The second voltage detection module 4 comprises a second operational amplifier circuit 41, a first input end of the second operational amplifier circuit 41 is connected with the firewire L at the front end of the first relay 1, a second input end of the second operational amplifier circuit 41 is connected with the zero line N at the rear end of the second relay 2, the second operational amplifier circuit 41 inputs the second input voltage, and outputs the second detection voltage to the control module 5 after processing the second input voltage according to the second proportional reduction, so that the second detection voltage output to the control module 5 by the second voltage detection module 4 conforms to the voltage range of the signal processed by the control module 5.

[0072] Optionally, the first proportional reduction and the second proportional reduction can be the same, that is, the first operational amplifier circuit 31 reduces the first input voltage by the same proportion as the second operational amplifier circuit 41 reduces the second input voltage.

[0073] Optionally, on the basis of the above embodiments, Figure 5 is another structural schematic diagram of a relay sticking fault detection circuit provided by the embodiment of the utility model, as Figure 5 shown, the first operational amplifier circuit 31 comprises a first operational amplifier U1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6. The first end of the first resistor R1 is connected with the firewire L at the rear end of the first relay 1, and the second end of the first resistor R1 is connected with the non-inverting input end of the first operational amplifier U1. The first end of the second resistor R2 is connected with the zero line N at the front end of the second relay 2, and the second end of the second resistor R2 is connected with the inverting input end of the first operational amplifier U1. The third resistor R3 is connected between the non-inverting input end and the output end of the first operational amplifier U1, and the fourth resistor R4 is connected between the inverting input end and the ground GND of the first operational amplifier U1. The fifth resistor R5 is connected between the output end of the first operational amplifier U1 and the control module 5, and the sixth resistor R6 is connected between the control module 5 and the first power supply V1.

[0074] Specifically, the resistance values of the first resistor R1 and the second resistor R2 can be set to be the same, the resistance values of the third resistor R3 and the fourth resistor R4 can be set to be the same, and the resistance values of the fifth resistor R5 and the sixth resistor R6 can be set to be the same. The power supply end of the first operational amplifier U1 is connected to the second power supply +VCC, and the ground end of the first operational amplifier U1 is connected to the third power supply -VCC. The voltage on the fire line L at the rear end of the first relay 1 is connected to the non-inverting input end of the first operational amplifier U1 through the first resistor R1, and the voltage on the zero line N at the front end of the second relay 2 is connected to the inverting input end of the first operational amplifier U1 through the second resistor R2. The first input voltage is processed by the first operational amplifier U1, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4 and the fifth resistor R5. The sixth resistor R6 is connected between the control module 5 and the first power supply V1. For example, the first power supply V1 can be 3.3V. The sixth resistor R6 is arranged to change the amplitude of the first input voltage after the processing, and finally outputs the first detection voltage to the control module 5, and the control module 5 calculates the first input voltage according to the first detection voltage.

[0075] Optionally, on the basis of the above embodiments, Figure 6 is another schematic structural diagram of a relay sticking fault detection circuit provided by the embodiment of the utility model, as Figure 6 shown, the second operational amplifier circuit 41 comprises: a second operational amplifier U2, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11 and a twelfth resistor R12. The first end of the seventh resistor R7 is connected to the fire line L at the front end of the first relay 1, and the second end of the seventh resistor R7 is connected to the non-inverting input end of the second operational amplifier U2. The first end of the eighth resistor R8 is connected to the zero line N at the rear end of the second relay 2, and the second end of the eighth resistor R8 is connected to the inverting input end of the second operational amplifier U2. The ninth resistor R9 is connected between the non-inverting input end and the output end of the second operational amplifier U2, and the tenth resistor R10 is connected between the inverting input end and the ground GND of the second operational amplifier U2. The eleventh resistor R11 is connected between the output end of the second operational amplifier U2 and the control module, and the twelfth resistor R12 is connected between the control module 5 and the first power supply V1.

[0076] Specifically, the resistance values of the seventh resistor R7 and the eighth resistor R8 can be set to be the same, the resistance values of the ninth resistor R9 and the tenth resistor R10 can be set to be the same, and the resistance values of the eleventh resistor R11 and the twelfth resistor R12 can be set to be the same. The power supply end of the second operational amplifier U2 is connected to the second power supply +VCC, and the ground end of the second operational amplifier U2 is connected to the third power supply -VCC. The voltage on the firewire L at the front end of the first relay 1 is input to the non-inverting input end of the second operational amplifier U2 through the seventh resistor R7, and the voltage on the zero line N at the rear end of the second relay 2 is input to the inverting input end of the second operational amplifier U2 through the eighth resistor R8. The second input voltage is processed by the second operational amplifier U2, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, and the eleventh resistor R11. The twelfth resistor R12 is connected between the control module 5 and the first power supply V1. The first power supply V1 can be 3.3V. The amplitude of the second input voltage after the processing is changed by the twelfth resistor R12, and the second detection voltage is finally output to the control module 5. The control module 5 calculates the second input voltage according to the second detection voltage.

[0077] Optionally, the resistance values of the first resistor R1 and the seventh resistor R7 can be set to be the same, the resistance values of the second resistor R2 and the eighth resistor R8 can be set to be the same, the resistance values of the third resistor R3 and the ninth resistor R9 can be set to be the same, the resistance values of the fourth resistor R4 and the tenth resistor R10 can be set to be the same, the resistance values of the fifth resistor R5 and the eleventh resistor R11 can be set to be the same, the resistance values of the sixth resistor R6 and the twelfth resistor R12 can be set to be the same, and the first operational amplifier U1 and the second operational amplifier U2 are the same kind of operational amplifier.

[0078] Optionally, on the basis of the above embodiments, Figure 7 is another structure schematic view of a relay sticking fault detection circuit provided by the embodiment of the utility model, as Figure 7 shown, the reference voltage generation module 6 includes: a third operational amplifier circuit 61. The first input end of the third operational amplifier circuit 61 is connected with the firewire L at the front end of the first relay 1, the second input end of the third operational amplifier circuit 61 is connected with the zero line N at the front end of the second relay 2, the third operational amplifier circuit 61 inputs the commercial voltage provided by the commercial power grid, and the output end of the third operational amplifier circuit 61 is connected with the control module 5. The third operational amplifier circuit 61 is used to output the reference voltage to the control module 5 after the commercial voltage is reduced according to a third proportion.

[0079] Specifically, the first input end of the third operational amplifier circuit 61 is connected with the firewire L at the front end of the first relay 1, the second input end of the third operational amplifier circuit 61 is connected with the zero line N at the front end of the second relay 2, and the output end of the third operational amplifier circuit 61 is connected with the control module 5. The third operational amplifier circuit inputs the mains voltage, and outputs the reference voltage to the control module 5 after reducing the mains voltage according to the third proportion. In this way, the reference voltage output to the control module 5 by the reference voltage generation module 6 conforms to the voltage range of the signal processed by the control module 5.

[0080] Optionally, on the basis of each of the above embodiments, Figure 8 is a structural schematic diagram of another relay sticking fault detection circuit provided by the utility model embodiment, as Figure 8 shown, the third operational amplifier circuit 61 comprises: a third operational amplifier U3, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17 and an eighteenth resistor R18. The first end of the thirteenth resistor R13 is connected with the firewire L at the front end of the first relay 1, and the second end of the thirteenth resistor R13 is connected with the non-inverting input end of the third operational amplifier U3. The first end of the fourteenth resistor R14 is connected with the zero line N at the front end of the second relay 2, and the second end of the fourteenth resistor R14 is connected with the inverting input end of the third operational amplifier U3. The fifteenth resistor R15 is connected between the non-inverting input end and the output end of the third operational amplifier U3, and the sixteenth resistor R16 is connected between the inverting input end and the ground GND of the third operational amplifier U3. The seventeenth resistor R17 is connected between the output end of the third operational amplifier U3 and the control module 5, and the eighteenth resistor R18 is connected between the control module 5 and the first power supply V1.

[0081] Specifically, the resistance values of the thirteenth resistor R13 and the fourteenth resistor R14 can be set to be the same, the resistance values of the fifteenth resistor R15 and the sixteenth resistor R16 can be set to be the same, and the resistance values of the seventeenth resistor R17 and the eighteenth resistor R18 can be set to be the same. The power supply end of the third operational amplifier U3 is connected to the second power supply +VCC, and the ground end of the third operational amplifier U3 is connected to the third power supply -VCC. The voltage on the fire wire L at the front end of the first relay 1 is connected to the non-inverting input end of the third operational amplifier U3 through the thirteenth resistor R13, and the voltage on the zero wire N at the front end of the second relay 2 is connected to the inverting input end of the third operational amplifier U3 through the fourteenth resistor R14. The third operational amplifier U3, the thirteenth resistor R13, the fourteenth resistor R14, the fifteenth resistor R15, the sixteenth resistor R16, and the seventeenth resistor R17 are configured to realize the scaling of the mains voltage. The eighteenth resistor R18 is connected between the control module 5 and the first power supply V1. For example, the first power supply V1 can be 3.3V. The eighteenth resistor R18 is configured to change the amplitude of the scaled mains voltage, and finally output a reference voltage to the control module 5, and the control module 5 calculates the mains voltage according to the reference voltage.

[0082] Optionally, the resistance values of the first resistor R1, the seventh resistor R7, and the thirteenth resistor R13 can be set to be the same, the resistance values of the second resistor R2, the eighth resistor R8, and the fourteenth resistor R14 can be set to be the same, the resistance values of the third resistor R3, the ninth resistor R9, and the fifteenth resistor R15 can be set to be the same, the resistance values of the fourth resistor R4, the tenth resistor R10, and the sixteenth resistor R16 can be set to be the same, the resistance values of the fifth resistor R5, the eleventh resistor R11, and the seventeenth resistor R17 can be set to be the same, the resistance values of the sixth resistor R6, the twelfth resistor R12, and the eighteenth resistor R18 can be set to be the same, and the first operational amplifier U1, the second operational amplifier U2, and the third operational amplifier U3 are the same type of operational amplifier.

[0083] Optionally, on the basis of the above embodiments, Figure 9 is another structural schematic diagram of a relay sticking fault detection circuit provided by the embodiment of the utility model, as Figure 9 shown, the first relay control module 7 comprises a nineteenth resistor R19 and a first transistor Q1. The first relay 1 comprises a first coil C1 and a first contact K1, and the first contact K1 is arranged on the fire wire L. The first end of the first coil C1 is connected to the second power supply +VCC, the second end of the first coil C1 is connected to the first end of the first transistor Q1, and the second end of the first transistor Q1 is grounded GND. The first end of the nineteenth resistor R19 is connected to the control module 5, and the second end of the nineteenth resistor R19 is connected to the control end of the first transistor Q1.

[0084] Specifically, the first transistor Q1 includes but is not limited to a field effect transistor, a bipolar transistor, or a combination of any transistor.Figure 9 The first transistor Q1 is exemplarily shown as an NPN type triode, which is not specifically limited herein.

[0085] When the first relay 1 needs to be detected for the stuck fault, the first relay 1 needs to be controlled to be closed and then opened, or to be opened and then closed. Exemplarily, the control module 5 sends a low-level signal to the control end of the first transistor Q1 through the nineteenth resistor R19, the first transistor Q1 is opened, and the first coil C1 has no current flowing therethrough. At this time, the first contact K1 is opened, that is, the first relay 1 is opened. The control module 5 sends a high-level signal to the control end of the first transistor Q1 through the nineteenth resistor R19, the first transistor Q1 is turned on, and the first coil C1 has current flowing therethrough. At this time, the first contact K1 is closed, that is, the first relay 1 is closed.

[0086] Optionally, based on the above embodiments, with reference to Figure 9 The second relay control module 8 comprises a twentieth resistor R20 and a second transistor Q2. The second relay 2 comprises a second coil C2 and a second contact K2, the second contact K2 is arranged on the zero line N, the first end of the second coil C2 is connected with the second power supply +VCC, the second end of the second coil C2 is connected with the first end of the second transistor Q2, and the second end of the second transistor Q2 is grounded GND. The first end of the twentieth resistor R20 is connected with the control module 5, and the second end of the twentieth resistor R20 is connected with the control end of the second transistor Q2.

[0087] Specifically, the second transistor Q2 comprises but is not limited to a field effect transistor, a bipolar transistor or a combination of any transistor. Figure 9 The second transistor Q2 is exemplarily shown as an NPN type triode, which is not specifically limited herein.

[0088] When the second relay 2 needs to be detected for the stuck fault, the second relay 2 needs to be controlled to be closed and then opened, or to be opened and then closed. Exemplarily, the control module 5 sends a low-level signal to the control end of the second transistor Q2 through the twentieth resistor R20, the second transistor Q2 is opened, and the second coil C2 has no current flowing therethrough. At this time, the second contact K2 is opened, that is, the second relay 2 is opened. The control module 5 sends a high-level signal to the control end of the second transistor Q2 through the twentieth resistor R20, the second transistor Q2 is turned on, and the second coil C2 has current flowing therethrough. At this time, the first contact K2 is closed, that is, the second relay 2 is closed.

[0089] When the load 10 is normally connected to the mains voltage provided by the firewire L and the zero line N, the voltage of the firewire L in front of the first relay 1 and the voltage of the zero line N in front of the second relay 2 are attenuated by the thirteenth resistor R13 and the fourteenth resistor R14 respectively, and then output the reference voltage to the control module 5 through the third operational amplifier U3, the fifteenth resistor R15, the sixteenth resistor R16, the seventeenth resistor R17 and the eighteenth resistor R18 according to the third proportional reduction processing, and the control module 5 calculates the mains voltage according to the reference voltage.

[0090] In the first relay 1 stick failure detection, the control module 5 sends a low level signal to control the first transistor Q1 off, that is, the control module 5 controls the first contact K1 open, the first input voltage provided by the live wire L at the back end of the first relay 1 and the zero line N at the front end of the second relay 2 passes through the first resistor R1, the second resistor R2, the first operational amplifier U1, the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 to output the first detection voltage to the control module 5 after the first proportional reduction processing, and the control module 5 calculates the first input voltage according to the first detection voltage. The control module 5 sends a high level signal to control the first transistor Q1 on, that is, the control module 5 controls the first contact K1 closed, the first input voltage provided by the live wire L at the back end of the first relay 1 and the zero line N at the front end of the second relay 2 passes through the first resistor R1, the second resistor R2, the first operational amplifier U1, the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 to output the first detection voltage to the control module 5 after the first proportional reduction processing, and the control module 5 calculates the first input voltage according to the first detection voltage. If the control module 5 detects that the first input voltage is zero when the control module 5 controls the first contact K1 open, and the control module 5 detects that the first input voltage is not zero and the same as the mains voltage when the control module 5 controls the first contact K1 closed, the control module 5 determines that the first relay 1 has no stick failure. If the control module 5 detects that the first input voltage is not zero and the same as the mains voltage when the control module 5 controls the first contact K1 open, and the control module 5 detects that the first input voltage is not zero and the same as the mains voltage when the control module 5 controls the first contact K1 closed, that is, no matter the control module 5 sends a high level signal or a low level signal to the control end of the first transistor Q1, the first contact K1 is always in the closed state, the control module 5 determines that the first relay 1 is stuck in the closed end contact. If the control module 5 detects that the first input voltage is zero when the control module 5 controls the first contact K1 open, and the control module 5 detects that the first input voltage is zero when the control module 5 controls the first contact K1 closed, that is, no matter the control module 5 sends a high level signal or a low level signal to the control end of the first transistor Q1, the first contact K1 is always in the open state, the control module 5 determines that the first relay 1 is stuck in the open end contact. Table 1 lists the results of the first relay stick failure detection.

[0091] Table 1 results of the first relay stick failure detection

[0092]

[0093] In the second relay 2 stick failure detection, the control module 5 sends low level signal control second transistor Q2 off, that is, the control module 5 controls the second contact K2 open, the second input voltage provided by the live wire L in front of the second relay 2 and the zero line N in the back of the second relay 2 through the seventh resistance R7, the eighth resistance R8, the second operational amplifier U2, the ninth resistance R9, the tenth resistance R10, the eleventh resistance R11 and the twelfth resistance R12 according to the second proportional reduction processing output second detection voltage to the control module 5, the control module 5 calculates the second input voltage according to the second detection voltage. The control module 5 sends high level signal control second transistor Q2 on, that is, the control module 5 controls the second contact K2 close, the second input voltage provided by the live wire L in front of the first relay 1 and the zero line N in the back of the second relay 2 through the seventh resistance R7, the eighth resistance R8, the second operational amplifier U2, the ninth resistance R9, the tenth resistance R10, the eleventh resistance R11 and the twelfth resistance R12 according to the second proportional reduction processing output second detection voltage to the control module 5, the control module 5 calculates the second input voltage according to the second detection voltage. If the control module 5 detects that the second input voltage is zero when the control module 5 controls the second contact K2 open, and the control module 5 detects that the second input voltage is not zero and the same as the mains voltage when the control module 5 controls the second contact K2 close, the control module 5 determines that the second relay 2 has no stick failure. If the control module 5 detects that the second input voltage is not zero and the same as the mains voltage when the control module 5 controls the second contact K2 open, and the control module 5 detects that the second input voltage is not zero and the same as the mains voltage when the control module 5 controls the second contact K2 close, that is, no matter the control module 5 sends high level signal or low level signal to the control end of the second transistor Q2, the second contact K2 is always in the closed state, the control module 5 determines that the second relay 2 is stuck in the closed end contact. If the control module 5 detects that the second input voltage is zero when the control module 5 controls the second contact K2 open, and the control module 5 detects that the second input voltage is zero when the control module 5 controls the second contact K2 close, that is, no matter the control module 5 sends high level signal or low level signal to the control end of the second transistor Q2, the second contact K2 is always in the open state, the control module 5 determines that the second relay 2 is stuck in the open end contact.

[0094] It should be understood that the various forms of flow shown above can be reordered, steps added or deleted. For example, the steps described in the present application can be executed in parallel, in sequence or in different order, as long as the desired results of the technical solution of the present application can be achieved, which is not limited herein.

[0095] The specific embodiments described above do not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A stuck relay fault detection circuit, characterized by, The utility model relates to a power supply system, including: First relay, second relay, first voltage detection module, second voltage detection module and control module; The first relay is arranged on the live wire of the commercial power grid, and the second relay is arranged on the zero line of the commercial power grid;The first input end of the first voltage detection module is connected with the live wire at the rear end of the first relay, and the second input end of the first voltage detection module is connected with the zero line at the front end of the second relay;The output end of the first voltage detection module is connected with the control module;The first input end of the second voltage detection module is connected with the live wire at the front end of the first relay, and the second input end of the second voltage detection module is connected with the zero line at the rear end of the second relay;The output end of the second voltage detection module is connected with the control module; The first voltage detection module is used for outputting the first detection voltage to the control module, and the control module is used for judging whether the first relay occurs sticking failure; The second voltage detection module is used for outputting the second detection voltage to the control module, and the control module is used for judging whether the second relay occurs sticking failure.

2. The stuck relay fault detection circuit of claim 1, wherein, Further including: Reference voltage generation module; The first input end of the reference voltage generation module is connected with the live wire at the front end of the first relay, the second input end of the reference voltage generation module is connected with the zero line at the front end of the second relay, the reference voltage generation module accesses the commercial voltage provided by the commercial power grid, and the output end of the reference voltage generation module is connected with the control module; The reference voltage generation module is used for outputting the reference voltage to the control module according to the commercial voltage, and the control module is used for judging whether the first relay occurs sticking failure according to the reference voltage and the first detection voltage;The control module is also used for judging whether the second relay occurs sticking failure according to the reference voltage and the second detection voltage.

3. The stuck relay fault detection circuit of claim 1, wherein, Further including: First relay control module and second relay control module; The first relay control module is connected with the first relay and the control module, and the second relay control module is connected with the second relay and the control module; The first relay control module is used for controlling the first relay to close or disconnect according to the first control signal sent by the control module, and the second relay control module is used for controlling the second relay to close or disconnect according to the second control signal sent by the control module.

4. The stuck relay fault detection circuit of claim 1, wherein, The first voltage detection module includes a first operational amplifier circuit, and the second voltage detection module includes a second operational amplifier circuit. The first input end of the first operational amplifier circuit is connected with the firewire at the rear end of the first relay, and the second input end of the first operational amplifier circuit is connected with the zero line at the front end of the second relay; the output end of the first operational amplifier circuit is connected with the control module; the first operational amplifier circuit is used for accessing the first input voltage provided by the firewire at the rear end of the first relay and the zero line at the front end of the second relay, and outputs the first detection voltage to the control module after reducing the first input voltage according to a first proportion; The first input end of the first operational amplifier circuit is connected with the firewire at the rear end of the first relay, and the second input end of the first operational amplifier circuit is connected with the zero line at the front end of the second relay; the output end of the first operational amplifier circuit is connected with the control module; the first operational amplifier circuit is used for accessing the first input voltage provided by the firewire at the rear end of the first relay and the zero line at the front end of the second relay, and outputs the first detection voltage to the control module after reducing the first input voltage according to a first proportion; 5. The stuck relay fault detection circuit of claim 4, wherein, The first operational amplifier circuit comprises a first operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor; The first end of the first resistor is connected with the firewire at the rear end of the first relay, and the second end of the first resistor is connected with the non-inverting input end of the first operational amplifier; the first end of the second resistor is connected with the zero line at the front end of the second relay, and the second end of the second resistor is connected with the inverting input end of the first operational amplifier; The third resistor is connected between the non-inverting input end and the output end of the first operational amplifier, the fourth resistor is connected between the inverting input end and the ground of the first operational amplifier; the fifth resistor is connected between the output end of the first operational amplifier and the control module, and the sixth resistor is connected between the control module and the first power supply.

6. The stuck relay fault detection circuit of claim 4, wherein, The second operational amplifier circuit comprises a second operational amplifier, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor and a twelfth resistor; The first end of the seventh resistor is connected with the firewire at the front end of the first relay, and the second end of the seventh resistor is connected with the non-inverting input end of the second operational amplifier; the first end of the eighth resistor is connected with the zero line at the rear end of the second relay, and the second end of the eighth resistor is connected with the inverting input end of the second operational amplifier; The ninth resistor is connected between the non-inverting input end and the output end of the second operational amplifier, the tenth resistor is connected between the inverting input end and the ground of the second operational amplifier; the eleventh resistor is connected between the output end of the second operational amplifier and the control module, and the twelfth resistor is connected between the control module and the first power supply.

7. The stuck relay fault detection circuit of claim 2, wherein, The reference voltage generation module comprises a third operational amplifier circuit; The first input end of the third operational amplifier circuit is connected with the live wire of the first relay front end, the second input end of the third operational amplifier circuit is connected with the zero line of the second relay front end, the third operational amplifier circuit is connected with the commercial voltage provided by the commercial power grid, and the output end of the third operational amplifier circuit is connected with the control module. The third operational amplifier circuit is used for outputting the reference voltage to the control module after reducing the commercial voltage in a third proportion.

8. The stuck relay fault detection circuit of claim 7, wherein, The third operational amplifier circuit comprises a third operational amplifier, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor and an eighteenth resistor. The first end of the thirteenth resistor is connected with the live wire of the first relay front end, and the second end of the thirteenth resistor is connected with the non-inverting input end of the third operational amplifier; the first end of the fourteenth resistor is connected with the zero line of the second relay front end, and the second end of the fourteenth resistor is connected with the inverting input end of the third operational amplifier. The fifteenth resistor is connected between the non-inverting input end and the output end of the third operational amplifier, the sixteenth resistor is connected between the inverting input end of the third operational amplifier and the ground, the seventeenth resistor is connected between the output end of the third operational amplifier and the control module, and the eighteenth resistor is connected between the control module and the first power supply.

9. The stuck relay fault detection circuit of claim 3, wherein, The first relay control module comprises a nineteenth resistor and a first transistor. The first relay comprises a first coil and a first contact, the first contact is arranged on the live wire, the first end of the first coil is connected with the second power supply, the second end of the first coil is connected with the first end of the first transistor, and the second end of the first transistor is grounded. The first end of the nineteenth resistor is connected with the control module, and the second end of the nineteenth resistor is connected with the control end of the first transistor.

10. The stuck relay fault detection circuit of claim 3, wherein, The second relay control module comprises a twentieth resistor and a second transistor. The second relay comprises a second coil and a second contact, the second contact is arranged on the zero line, the first end of the second coil is connected with the second power supply, the second end of the second coil is connected with the first end of the second transistor, and the second end of the second transistor is grounded. The first end of the twentieth resistor is connected with the control module, and the second end of the twentieth resistor is connected with the control end of the second transistor.

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