A relay drive circuit

Abstract

The application discloses a relay driving circuit, comprising a power module, a starting switch, a main control module and a switch module, the power module is used for providing stable working voltage for the system, the starting switch is used for outputting a starting signal of the relay, a control signal input end of the main control module is connected with the starting switch, the main control module is used for outputting a corresponding pulse driving signal according to the starting signal, an input end of the switch module is connected with a control signal output end of the main control module, an output end of the switch module is electrically connected with the relay, and the switch module is used for driving the relay to work according to the pulse driving signal. The switch module of the application can drive the relay to work according to the pulse driving signal, compared with the traditional relay directly driven by the switch, when the program of the main control module runs out of control or crashes, the pulse driving signal will stop outputting, thereby stopping driving the relay and making the load stop working, and further preventing the household appliance from burning or the occurrence of safety accidents.

Description

Technical Field

[0001] This utility model relates to the field of electronic technology, and in particular to a relay drive circuit. Background Technology

[0002] Relays, as key electrical control devices for automatic circuit switching, are widely used in industrial control, automation equipment, and various electronic systems. Currently, relays are typically driven by DC drive circuits, meaning the relay's state is determined by the high / low level of the control signal; generally, a high level drives the relay to operate, and a low level stops it from operating.

[0003] However, with existing DC drive methods, when the control chip malfunctions or the program crashes or freezes due to external interference, the MCU's I / O ports may continuously output a high level or a low level, causing the relay to conduct abnormally, which in turn can lead to the burning of household appliances or safety accidents. Utility Model Content

[0004] To address the technical problem that when a relay is driven by DC, abnormal conduction of the relay can occur when the control chip malfunctions or crashes, leading to equipment burnout and other safety accidents, this utility model provides a relay drive circuit.

[0005] To achieve the above objectives, this utility model is implemented by the following technical solution:

[0006] A relay drive circuit, comprising:

[0007] A power module, wherein the power output terminal of the power module is electrically connected to a relay, and the power module is used to provide a stable operating voltage for the system;

[0008] A start switch, which is used to output a start signal for the relay;

[0009] The main control module has its control signal input terminal connected to the start switch, and the main control module is used to output a corresponding pulse drive signal according to the start signal.

[0010] The switch module has its input terminal connected to the control signal output terminal of the main control module, and its output terminal electrically connected to a relay. The switch module is used to drive the relay to work according to the pulse drive signal.

[0011] By adopting the above technical solution, the switch module can drive the relay to work according to the pulse drive signal. Compared with the traditional method of directly driving the relay through the switch, the pulse drive signal will stop outputting when the main control module crashes or freezes, thereby stopping the relay from driving and the load from working, thus preventing household appliances from burning out or causing safety accidents.

[0012] Secondly, since the pulse drive method does not continuously supply power to the relay coil, it helps to reduce the average power consumption of the relay coil, reduce the heat accumulation caused by the relay coil being energized for a long time, thereby avoiding overheating and damage to the relay coil and extending the service life of the relay.

[0013] As described above, in a relay drive circuit, the switching module includes:

[0014] A signal amplification unit, the input terminal of which is connected to the control signal output terminal of the main control module, is used to amplify and output the pulse drive signal;

[0015] A filtering unit is provided, the input of which is connected to the output of the signal amplification unit. The filtering unit is used to filter the amplified pulse drive signal.

[0016] The control unit has its input terminal connected to the output terminal of the filtering unit and its output terminal electrically connected to the relay. The control unit is used to drive the relay to work after receiving the filtered pulse drive signal.

[0017] As described above, in a relay driving circuit, the signal amplification unit includes a transistor Q1, a capacitor C1, a resistor R1, and a resistor R2. The control signal output terminal of the main control module is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the emitter of the transistor Q1, and the other end of the resistor R1 is also connected to the base of the transistor Q1. The collector of the transistor Q1 is connected to the input terminal of the filtering unit.

[0018] As described above, in a relay drive circuit, the filtering unit includes a resistor R3 and a polarized capacitor EC1. The output terminal of the signal amplification unit is connected to one end of the resistor R3, the other end of the resistor R3 is connected to the positive terminal of the polarized capacitor EC1, the negative terminal of the polarized capacitor EC1 is grounded, and the other end of the resistor R3 is connected to the input terminal of the control unit.

[0019] As described above, in a relay driving circuit, the control unit includes a transistor Q2 and a resistor R4. The output terminal of the filter unit is connected to the base of the transistor Q2. The resistor R4 is also connected between the output terminal of the filter unit and ground. The emitter of the transistor Q2 is grounded, and the collector of the transistor Q2 is electrically connected to the relay.

[0020] As described above, in a relay drive circuit, the power supply module includes:

[0021] A rectifier unit, the input terminal of which is connected to the mains power, is used to rectify the mains power into direct current;

[0022] The protection unit has its input terminal connected to the output terminal of the rectifier unit. The protection unit is used to cut off the circuit output when the DC current experiences overcurrent / overvoltage.

[0023] A voltage conversion unit is provided, wherein the input terminal of the voltage conversion unit is connected to the output terminal of the protection unit, the first output terminal of the voltage conversion unit is connected to a relay, and the voltage conversion unit is used to convert the DC power into a first DC voltage, and the second output terminal of the voltage conversion unit is used to convert the DC power into a second DC voltage.

[0024] As described above, in a relay drive circuit, the rectifier unit includes a fuse FULE, a thermistor FR1, a rectifier bridge BD1, an inductor L1, resistors R5 and R6. The live wire is connected to one end of the fuse FULE, and the other end of the fuse FULE is connected to one end of the thermistor FR1. The other end of the thermistor FR1 is connected to the first input terminal of the rectifier bridge BD1. The neutral wire is connected to the second input terminal of the rectifier bridge BD1. The negative output terminal of the rectifier bridge BD1 is grounded, and the positive output terminal of the rectifier bridge BD1 is connected to one end of the inductor L1. The other end of the inductor L1 is connected to the input terminal of the protection unit via resistors R5 and R6 connected in series.

[0025] As described above, in a relay drive circuit, the protection unit includes a protection chip U1, a diode D1, a resistor R8, and a capacitor C2. The output terminal of the rectifier unit is connected to the input terminal of the protection chip U1. The output terminal of the protection chip U1 is connected to the positive terminal of the diode D1. The negative terminal of the diode D1 is connected to one end of the resistor R8. The other end of the resistor R8 is connected to the input terminal of the voltage conversion unit. The negative terminal of the diode D1 is also connected to one end of the capacitor C2. The other end of the capacitor C2 is also connected to the input terminal of the voltage conversion unit.

[0026] As described above, in a relay drive circuit, the voltage conversion unit includes a transformer T1, diodes D2, D3, and D4, polarized capacitors EC4 and EC6, and a resistor R11. The output terminal of the rectifier unit is connected to the first input terminal of the primary winding of the transformer T1. The output terminal of the protection unit is connected to the second input terminal of the primary winding of the transformer T1. The fourth input terminal of the primary winding of the transformer T1 is grounded. The fifth input terminal of the primary winding of the transformer T1 is connected to the positive terminal of diode D2. The negative terminal of diode D2 is connected to the positive terminal of polarized capacitor EC4, and the negative terminal of polarized capacitor EC4 is grounded. The first output terminal of the secondary winding of the transformer T1 is connected to the positive terminal of diode D3. The negative terminal of diode D3 is connected to the first output terminal of the voltage conversion unit. The resistor R11 is connected between the first output terminal and the second output terminal of the voltage conversion unit.

[0027] The second output terminal of the secondary winding of the transformer T1 is connected to the positive terminal of the diode D4, the negative terminal of the diode D4 is connected to the second output terminal of the voltage conversion unit, the polarized capacitor EC6 is connected between the second output terminal of the voltage conversion unit and ground, and the third output terminal of the secondary winding of the transformer T1 is grounded.

[0028] As described above, in a relay drive circuit, the power supply module further includes a step-down unit. The input terminal of the step-down unit is connected to the second output terminal of the voltage conversion unit, and the output terminal of the step-down unit is connected to the power input terminal of the main control module. The step-down unit is used to step down the second DC voltage to a stable third DC voltage, thereby providing a stable operating voltage for the main control module.

[0029] Compared with the prior art, the relay drive circuit proposed in this utility model has the following beneficial effects:

[0030] 1. The switch module and main control module proposed in this utility model can drive the relay to work according to the pulse drive signal. Compared with the traditional method of directly driving the relay through the switch, the pulse drive signal will stop outputting when the main control module crashes or freezes, thereby stopping the relay from driving and stopping the load from working, thus preventing the household appliances from burning out or causing safety accidents. Secondly, since the pulse drive method does not continuously supply power to the relay coil, it helps to reduce the average power consumption of the relay coil, reduce the heat accumulation of the relay coil due to long-term power supply, thereby avoiding the relay coil overheating and damage, and extending the service life of the relay.

[0031] 2. The switching module proposed in this utility model includes a signal amplification unit, a filtering unit, and a control unit. The signal amplification unit amplifies the pulse drive signal, effectively compensating for signal loss during transmission, ensuring reliable control of transistor Q2 to drive the relay to work normally, and avoiding the relay's inability to work properly due to signal transmission loss making it difficult to drive transistor Q2 to conduct. The filtering unit removes high-frequency noise and interference waves from the pulse drive signal, making the pulse drive signal smoother and more stable, improving signal quality, preventing interference signals from causing relay malfunction, and enhancing the anti-interference capability of the drive circuit. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0033] Figure 1 This is a block diagram illustrating the circuit principle structure of this utility model;

[0034] Figure 2 This is a circuit diagram of the power module of this utility model;

[0035] Figure 3 This is a partial circuit diagram of the main control module and the switch module of this utility model. Detailed Implementation

[0036] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model 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 merely illustrative of the present utility model and are not intended to limit the present utility model.

[0037] The relay drive circuit proposed in this specification is applied to household appliances, including but not limited to kettles, ovens, coffee grinders, and other household appliances that use relays to control loads (heating tubes, AC motors). This specification mainly uses kettles as an example to illustrate the implementation scenario. Other household appliances can be implemented by referring to this scenario, and this application will not elaborate further.

[0038] Specific embodiments, combined with Figures 1 to 3As shown, the technical solution of this utility model is further illustrated. A relay driving circuit includes a power supply module 100, a start switch K1, a main control module 200, and a switch module 300. The power output terminal of the power supply module 100 is electrically connected to the relay, and the power supply module 100 is used to provide a stable operating voltage for the system. The start switch K1 is used to output a start signal for the relay. The control signal input terminal of the main control module 200 is connected to the start switch K1, and the main control module 200 is used to output a corresponding pulse drive signal according to the start signal. The input terminal of the switch module 300 is connected to the control signal output terminal of the main control module 200, and the output terminal of the switch module 300 is electrically connected to the relay. The switch module 300 is used to drive the relay to work according to the pulse drive signal.

[0039] In this embodiment, the switch module can drive the relay to work according to the pulse drive signal. Compared with the traditional method of directly driving the relay through the switch, the pulse drive signal will stop outputting when the main control module crashes or freezes, thereby stopping the relay from driving and causing the load to stop working, thus preventing the household appliances from burning out or causing safety accidents.

[0040] Secondly, since the pulse drive method does not continuously supply power to the relay coil, it helps to reduce the average power consumption of the relay coil, reduce the heat accumulation caused by the relay coil being energized for a long time, thereby avoiding overheating and damage to the relay coil and extending the service life of the relay.

[0041] Furthermore, as a preferred embodiment of this solution and not a limitation thereof, the power module 100 includes a rectifier unit 110, a protection unit 120, and a voltage conversion unit 130. The input terminal of the rectifier unit 110 is connected to the mains power supply, and the rectifier unit 110 is used to rectify the mains power supply into direct current (DC). The input terminal of the protection unit 120 is connected to the output terminal of the rectifier unit 110, and the protection unit 120 is used to cut off the circuit output when the DC power supply experiences overcurrent / overvoltage. The input terminal of the voltage conversion unit 130 is connected to the output terminal of the protection unit 120. The first output terminal of the voltage conversion unit 130 is connected to a relay and is used to convert the DC power supply into a first DC voltage. The second output terminal of the voltage conversion unit 130 is used to convert the DC power supply into a second DC voltage.

[0042] In this embodiment, the first DC voltage is preferably 12V DC voltage, and the second DC voltage is preferably 8V DC voltage.

[0043] In a preferred embodiment, the rectifier unit 110 includes a fuse FULE, a thermistor FR1, a rectifier bridge BD1, an inductor L1, a resistor R5, and a resistor R6. The live wire (i.e., the AC_L terminal) is connected to one end of the fuse FULE, and the other end of the fuse FULE is connected to one end of the thermistor FR1. The other end of the thermistor FR1 is connected to the first input terminal (i.e., pin 1) of the rectifier bridge BD1, and the neutral wire (i.e., the AC_N terminal) is connected to the second input terminal (i.e., pin 2) of the rectifier bridge BD1. The negative output terminal of the rectifier bridge BD1 is grounded, and the positive output terminal of the rectifier bridge BD1 is connected to one end of the inductor L1. The other end of the inductor L1 is connected to the input terminal of the protection unit 120 via resistors R5 and R6 connected in series.

[0044] Alternatively, the rectifier bridge BD1 is model ABS10.

[0045] In this embodiment, the fuse FULE and the thermistor FR1 protect the circuit, enabling the circuit to be cut off in time when an overload or short circuit occurs. The thermistor FR1 also suppresses the surge current generated at the moment of power-on, avoiding the risk of electric shock when the equipment is powered on.

[0046] Secondly, the rectifier bridge BD1 rectifies the AC power (i.e., mains power) into DC power, providing a stable DC power supply for other subsequent circuits. The inductor L1 filters the rectified DC power supply, reducing ripple and making it closer to the ideal DC power, thus improving power quality.

[0047] In a preferred embodiment, the protection unit 120 includes a protection chip U1, a diode D1, a resistor R8, and a capacitor C2. The output terminal of the rectifier unit 110 is connected to the input terminal (i.e., the VIN terminal) of the protection chip U1. The output terminal (i.e., the HV terminal) of the protection chip U1 is connected to the positive terminal of the diode D1. The negative terminal of the diode D1 is connected to one end of the resistor R8. The other end of the resistor R8 is connected to the input terminal of the voltage conversion unit 130. The negative terminal of the diode D1 is also connected to one end of the capacitor C2. The other end of the capacitor C2 is also connected to the input terminal of the voltage conversion unit 130.

[0048] Alternatively, the protection chip U1 is model LN5R04DA.

[0049] In this embodiment, the protection chip LN5R04DA has overcurrent, overvoltage, and undervoltage protection functions. It can monitor the rectified DC current in real time and cut off the circuit or limit the current in time when abnormalities such as overcurrent / overvoltage occur to prevent damage to other subsequent circuits. Secondly, the setting of diode D1 prevents current backflow and avoids the protection chip LN5R04DA from being damaged by reverse current, thereby enhancing the safety of the circuit.

[0050] In a preferred embodiment, the voltage conversion unit 130 includes a transformer T1, diodes D2, D3, and D4, polarized capacitors EC4 and EC6, and a resistor R11. The output terminal of the rectifier unit 110 is connected to the first input terminal (pin 1) of the primary winding of the transformer T1. The output terminal of the protection unit 120 is connected to the second input terminal (pin 2) of the primary winding of the transformer T1. The fourth input terminal (pin 4) of the primary winding of the transformer T1 is grounded, and the fifth input terminal (pin 5) of the primary winding of the transformer T1 is connected to... The positive terminal of diode D2 is connected to the ground, the negative terminal of diode D2 is connected to the positive terminal of polarized capacitor EC4, the negative terminal of polarized capacitor EC4 is grounded, the first output terminal (i.e., pin 6) of the secondary winding of transformer T1 is connected to the positive terminal of diode D3, the negative terminal of diode D3 is connected to the first output terminal (i.e., +12V terminal) of voltage conversion unit 130, and the resistor R11 is connected between the first output terminal (i.e., +12V terminal) and the second output terminal (i.e., +8V terminal) of voltage conversion unit 130.

[0051] The second output terminal (pin 8) of the secondary winding of the transformer T1 is connected to the positive terminal of the diode D4, the negative terminal of the diode D4 is connected to the second output terminal (+8V terminal) of the voltage conversion unit 130, the polarized capacitor EC6 is connected between the second output terminal (+8V terminal) of the voltage conversion unit 130 and ground, and the third output terminal of the secondary winding of the transformer T1 is grounded.

[0052] Alternatively, the transformer T1 is of model EE13.

[0053] In this embodiment, a diode D2 and a polarized capacitor EC4 are connected to the fifth input terminal (pin 5) of the primary winding of transformer T1. During the operation of transformer T1, diode D2 and polarized capacitor EC4 form a clamping circuit. When the voltage of the primary winding of transformer T1 rises to a certain level, diode D2 conducts and polarized capacitor EC4 charges, stabilizing the voltage within a relatively safe range and preventing excessive voltage from damaging transformer T1. Secondly, a resistor R11 connected between the first output terminal (+12V terminal) and the second output terminal (+8V terminal) of voltage conversion unit 130 is used to divide the +12V voltage to obtain the +8V voltage.

[0054] Furthermore, as a preferred embodiment of this solution and not a limitation, the power module 100 also includes a step-down unit 140. The input terminal of the step-down unit 140 is connected to the second output terminal (i.e., +8V terminal) of the voltage conversion unit 130, and the output terminal of the step-down unit 140 is connected to the power input terminal (i.e., VDD terminal) of the main control module 200. The step-down unit 140 is used to step down the second DC voltage to a stable third DC voltage, thereby providing a stable operating voltage for the main control module 200.

[0055] In this embodiment, the third DC voltage is a 5V DC voltage.

[0056] In a preferred embodiment, the step-down unit 140 includes a linear regulator U2 and a resistor R15. The second output terminal (i.e., +8V terminal) of the voltage conversion unit 130 is connected to the input terminal (i.e., I terminal) of the linear regulator U2. The output terminal (i.e., O terminal) of the linear regulator U2 is connected to one end of the resistor R15, and the other end of the resistor R15 is connected to the power input terminal (i.e., VDD terminal) of the main control module 200.

[0057] Alternatively, the linear regulator U2 is model 78L05.

[0058] In this embodiment, the linear regulator 78L05 stably reduces the input +8V voltage to +5V, providing a stable +5V power supply to the main control module, ensuring that the main control module can obtain a stable power supply and improving the stability of the system. Secondly, the linear regulator 78L05 can filter the output voltage, reducing the impact of power supply noise on the main control module and improving the working performance and stability of the main control module.

[0059] Furthermore, as a preferred embodiment of this solution and not a limitation, the main control module 200 includes a main control chip MCU, and the model of the main control chip MCU in this embodiment is preferably FT60F123.

[0060] Furthermore, as a preferred embodiment of this solution and not a limitation, the switching module 300 includes a signal amplification unit 310, a filtering unit 320, and a control unit 330. The input terminal of the signal amplification unit 310 is connected to the control signal output terminal of the main control module 220, and the signal amplification unit 310 is used to amplify and output the pulse drive signal. The input terminal of the filtering unit 320 is connected to the output terminal of the signal amplification unit 310, and the filtering unit 320 is used to filter the amplified pulse drive signal. The input terminal of the control unit 330 is connected to the output terminal of the filtering unit 320, and the output terminal of the control unit 330 is connected to a relay, and the control unit 330 is used to receive the filtered pulse drive signal and drive the relay to work.

[0061] In a preferred embodiment, the signal amplification unit 310 includes a transistor Q1, a capacitor C1, a resistor R1, and a resistor R2. The control signal output terminal (i.e., pin 12) of the main control module 200 is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the emitter of the transistor Q1, the other end of the resistor R1 is also connected to the base of the transistor Q1, and the collector of the transistor Q1 is connected to the input terminal of the filter unit 320.

[0062] In a preferred embodiment, the filter unit 320 includes a resistor R3 and a polarized capacitor EC1. The output terminal of the signal amplification unit 310 is connected to one end of the resistor R3, the other end of the resistor R3 is connected to the positive terminal of the polarized capacitor EC1, the negative terminal of the polarized capacitor EC1 is grounded, and the other end of the resistor R3 is connected to the input terminal of the control unit 330.

[0063] In a preferred embodiment, the control unit 330 includes a transistor Q2 and a resistor R4. The output terminal of the filter unit 320 is connected to the base of the transistor Q2. The resistor R4 is also connected between the output terminal of the filter unit 320 and ground. The emitter of the transistor Q2 is grounded, and the collector of the transistor Q2 is electrically connected to a relay.

[0064] Specifically, when the start switch K1 is pressed, the control signal input terminal (pin 4) of the main control module 200 receives the start signal from the start switch K1. The control signal output terminal (pin 12) of the main control module 200 will periodically output a square wave signal (i.e., pulse drive signal) with a frequency of 1KHz. The pulse drive signal is first amplified by the signal amplification unit 310 to ensure that the pulse drive signal will not be distorted due to loss during transmission. Then, the filtering unit 320 filters the amplified pulse drive signal to remove high-frequency noise and interference waves in the pulse signal, making the pulse drive signal smoother and more stable, and improving the purity and quality of the pulse drive signal. After the base of the transistor Q2 receives the filtered pulse drive signal, the transistor Q2 turns on, so that the pulse drive signal drives the relay to engage through the transistor Q2, controlling the load to start working.

[0065] If the main control module 200 crashes or the program malfunctions during operation, or if the main control module 200 receives a stop command, the control signal output terminal (i.e., pin 12) of the main control module 200 will stop outputting pulse drive signals. At this time, the base voltage of transistor Q1 in the signal amplification unit 310 will be lower than the drive voltage, and transistor Q1 will be cut off. The voltage on the polarized capacitor EC1 will discharge through resistor R4, causing the base voltage of transistor Q2 to be lower than the drive voltage, and transistor Q2 will be cut off, thereby disconnecting the relay. The load will also be de-energized and stop working.

[0066] In this embodiment, the signal amplification unit amplifies the pulse drive signal, effectively compensating for signal loss during transmission, ensuring reliable control of transistor Q2 to turn on, and driving the relay to work normally. This avoids the relay failing to work properly due to signal transmission loss making it difficult to turn on transistor Q2. The filtering unit removes high-frequency noise and interference waves from the pulse drive signal, making the pulse drive signal smoother and more stable, improving signal quality, preventing interference signals from causing relay malfunctions, and enhancing the anti-interference capability of the drive circuit.

[0067] Secondly, when the main control module encounters a bug or the program crashes or freezes due to external interference during operation, it can promptly cut off transistors Q1 and Q2, causing the relay to stop working quickly. This prevents the relay from continuing to engage during abnormalities, which could lead to equipment failure or even safety accidents, thus ensuring the operational safety of the relay drive circuit.

[0068] Those skilled in the art should understand that the above description is one embodiment provided in conjunction with specific content, and does not imply that the specific implementation of this utility model is limited to these descriptions. Furthermore, due to differences in industry naming conventions, it is not limited to the above names or English names. Any methods or structures similar to or identical to those of this utility model, or any technical deductions or substitutions made based on the concept of this utility model, should be considered within the scope of protection of this utility model.

Claims

1. A relay drive circuit, characterized in that, include: A power module, wherein the power output terminal of the power module is electrically connected to a relay, and the power module is used to provide a stable operating voltage for the system; A start switch, which is used to output a start signal for the relay; The main control module has its control signal input terminal connected to the start switch, and the main control module is used to output a corresponding pulse drive signal according to the start signal. The switch module has its input terminal connected to the control signal output terminal of the main control module, and its output terminal electrically connected to a relay. The switch module is used to drive the relay to work according to the pulse drive signal.

2. The relay driving circuit according to claim 1, characterized in that, The switching module includes: A signal amplification unit, the input terminal of which is connected to the control signal output terminal of the main control module, is used to amplify and output the pulse drive signal; A filtering unit is provided, the input of which is connected to the output of the signal amplification unit. The filtering unit is used to filter the amplified pulse drive signal. The control unit has its input terminal connected to the output terminal of the filtering unit and its output terminal electrically connected to the relay. The control unit is used to drive the relay to work after receiving the filtered pulse drive signal.

3. A relay driving circuit according to claim 2, characterized in that, The signal amplification unit includes a transistor Q1, a capacitor C1, a resistor R1, and a resistor R2. The control signal output terminal of the main control module is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the emitter of the transistor Q1, and the other end of the resistor R1 is also connected to the base of the transistor Q1. The collector of the transistor Q1 is connected to the input terminal of the filtering unit.

4. A relay driving circuit according to claim 2, characterized in that, The filtering unit includes a resistor R3 and a polarized capacitor EC1. The output terminal of the signal amplification unit is connected to one end of the resistor R3, the other end of the resistor R3 is connected to the positive terminal of the polarized capacitor EC1, the negative terminal of the polarized capacitor EC1 is grounded, and the other end of the resistor R3 is connected to the input terminal of the control unit.

5. A relay driving circuit according to claim 2, characterized in that, The control unit includes a transistor Q2 and a resistor R4. The output terminal of the filter unit is connected to the base of the transistor Q2. The output terminal of the filter unit is also connected to ground via the resistor R4. The emitter of the transistor Q2 is grounded, and the collector of the transistor Q2 is electrically connected to a relay.

6. A relay driving circuit according to claim 1, characterized in that, The power module includes: A rectifier unit, the input terminal of which is connected to the mains power, is used to rectify the mains power into direct current; The protection unit has its input terminal connected to the output terminal of the rectifier unit. The protection unit is used to cut off the circuit output when the DC current experiences overcurrent / overvoltage. A voltage conversion unit is provided, wherein the input terminal of the voltage conversion unit is connected to the output terminal of the protection unit, the first output terminal of the voltage conversion unit is connected to a relay, and the voltage conversion unit is used to convert the DC power into a first DC voltage, and the second output terminal of the voltage conversion unit is used to convert the DC power into a second DC voltage.

7. A relay driving circuit according to claim 6, characterized in that, The rectifier unit includes a fuse FULE, a thermistor FR1, a rectifier bridge BD1, an inductor L1, a resistor R5, and a resistor R6. The live wire is connected to one end of the fuse FULE, and the other end of the fuse FULE is connected to one end of the thermistor FR1. The other end of the thermistor FR1 is connected to the first input terminal of the rectifier bridge BD1, and the neutral wire is connected to the second input terminal of the rectifier bridge BD1. The negative output terminal of the rectifier bridge BD1 is grounded, and the positive output terminal of the rectifier bridge BD1 is connected to one end of the inductor L1. The other end of the inductor L1 is connected to the input terminal of the protection unit via resistors R5 and R6 connected in series.

8. A relay driving circuit according to claim 6, characterized in that, The protection unit includes a protection chip U1, a diode D1, a resistor R8, and a capacitor C2. The output terminal of the rectifier unit is connected to the input terminal of the protection chip U1. The output terminal of the protection chip U1 is connected to the positive terminal of the diode D1. The negative terminal of the diode D1 is connected to one end of the resistor R8. The other end of the resistor R8 is connected to the input terminal of the voltage conversion unit. The negative terminal of the diode D1 is also connected to one end of the capacitor C2. The other end of the capacitor C2 is also connected to the input terminal of the voltage conversion unit.

9. A relay driving circuit according to claim 6, characterized in that, The voltage conversion unit includes a transformer T1, diodes D2, D3, and D4, polarized capacitors EC4 and EC6, and a resistor R11. The output terminal of the rectifier unit is connected to the first input terminal of the primary winding of the transformer T1. The output terminal of the protection unit is connected to the second input terminal of the primary winding of the transformer T1. The fourth input terminal of the primary winding of the transformer T1 is grounded. The fifth input terminal of the primary winding of the transformer T1 is connected to the positive terminal of diode D2. The negative terminal of diode D2 is connected to the positive terminal of polarized capacitor EC4. The negative terminal of polarized capacitor EC4 is grounded. The first output terminal of the secondary winding of the transformer T1 is connected to the positive terminal of diode D3. The negative terminal of diode D3 is connected to the first output terminal of the voltage conversion unit. The resistor R11 is connected between the first output terminal and the second output terminal of the voltage conversion unit. The second output terminal of the secondary winding of the transformer T1 is connected to the positive terminal of the diode D4, the negative terminal of the diode D4 is connected to the second output terminal of the voltage conversion unit, the polarized capacitor EC6 is connected between the second output terminal of the voltage conversion unit and ground, and the third output terminal of the secondary winding of the transformer T1 is grounded.

10. A relay driving circuit according to claim 6, characterized in that, The power module also includes a step-down unit. The input terminal of the step-down unit is connected to the second output terminal of the voltage conversion unit, and the output terminal of the step-down unit is connected to the power input terminal of the main control module. The step-down unit is used to step down the second DC voltage to a stable third DC voltage, so as to provide a stable operating voltage for the main control module.

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