Relay driving circuit
By using a buck module and a switch module in the relay drive circuit, the relay can be absorbed and maintained by only one power supply, which solves the problem of requiring two power supplies in the prior art and reduces efficiency and cost.
Patent Information
- Application Number
- CN202421873299.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-02
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-08-02
AI Technical Summary
Existing relay drive circuits require two power supplies, resulting in reduced efficiency and increased cost.
Through a relay driving circuit, the step-down module and the switching module are used to achieve the relay's suction and maintenance suction and connection with only one power supply.
The relay is achieved and maintaining the suction connection requires only one power supply, reducing power consumption and cost while reducing circuit complexity and size.
Smart Images
Figure CN223038854U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of relay driving, and particularly relates to a relay driving circuit. Background Art
[0002] In the related art, in order to reduce the loss of the relay, two power supplies are adopted for the relay, that is, when the relay is attracted, it is powered by a power supply with a higher voltage, and when the relay maintains the attracted state, it is powered by a power supply with a lower voltage, so that the relay can have sufficient attraction force when attracted and can be more power-saving when maintaining the attracted state.
[0003] However, the above driving method requires two power supplies, and the two power supplies will bring about a reduction in efficiency and an increase in cost. Summary of the Utility Model
[0004] An embodiment of this application provides a relay driving circuit, which only requires one power supply to achieve the attraction and maintenance of the attraction of the relay.
[0005] An embodiment of this application provides a relay driving circuit. The relay driving circuit includes a first power supply terminal, a grounding terminal, a voltage reduction module, and a switch module. The first power supply terminal is connected to the first end of the relay, and the first power supply terminal is used to output a first voltage; the grounding terminal is connected to the second end of the relay; the input end of the voltage reduction module is connected to the second end of the relay, and the output end of the voltage reduction module is connected to the grounding terminal. The voltage reduction module is used to adjust the voltage across the relay; the first end of the switch module is connected to the output end of the voltage reduction module, and the second end of the switch module is connected to the grounding terminal; the voltage reduction module can adjust the voltage across the relay to be the first voltage or the second voltage, and the first voltage is higher than the second voltage; when the voltage across the relay is the first voltage, the relay can change from the off state to the attracted state; when the voltage across the relay is the second voltage, the relay can maintain the attracted state.
[0006] Beneficial Effects: In the embodiment of this application, the voltage across the relay is adjusted by the voltage reduction module. When the voltage across the relay is the first voltage, the relay has sufficient attraction force and can change from the off state to the attracted state. When the voltage reduction module reduces the voltage across the relay and the voltage across the relay is the second voltage, the relay can maintain the attracted state, thus being more power-saving. Description of the Drawings
[0007] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.
[0008] Figure 1 It is a schematic circuit diagram of a relay drive circuit in an embodiment of the present application;
[0009] Figure 2 It is a block diagram of a relay drive circuit in an embodiment of the present application;
[0010] Figure 3 It is a block diagram of a relay drive circuit in another embodiment of the present application;
[0011] Figure 4 It is a block diagram of a relay drive circuit in yet another embodiment of the present application;
[0012] Figure 5 It is a schematic circuit diagram of a relay drive circuit in another embodiment of the present application.
[0013] Explanation of reference numerals: 100, relay drive circuit; 110, first power supply terminal; 120, grounding terminal; 130, relay; 140, step-down module; 141, energy storage unit; 142, first switch; 143, voltage dividing unit; 144, discharging unit; 150, switch module; 151, second switch; 152, optocoupler; 153, third switch; 160, second power supply terminal;
[0014] C3, energy storage capacitor; C2, first filter capacitor; C4, second filter capacitor; C1, third filter capacitor; C5, fourth filter capacitor; Q4, first switching transistor; Q3, second switching transistor; Q2, third switching transistor;
[0015] Q1, fourth switching transistor; R10, first voltage dividing resistor; R6, second voltage dividing resistor; R7, third voltage dividing resistor; R2, fourth voltage dividing resistor; R9, first current limiting resistor; R8, second current limiting resistor; R5, third current limiting resistor; R1, fourth current limiting resistor; R3, fifth current limiting resistor; R4, sixth current limiting resistor; D1, diode; D2, zener diode. Detailed implementation manners
[0016] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the following further details the present application in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0017] As Figure 1 shown, it is a relay drive circuit of related technologies. The drive principle of the relay is voltage conversion drive, that is, the voltage at the moment when the relay is pulled in is a relatively high voltage VCC3, and the voltage for maintaining the relay being pulled in is a relatively low voltage VCC4. The operation of this circuit can be divided into four stages.
[0018] Stage 1: Relay_DRV is at a low level. At this time, the switching transistor Q4 is turned off, the optocoupler U1 is not conducting, the switching transistors Q1 - Q4 are turned off, the voltage across the relay coil is 0V, and the relay is turned off.
[0019] Stage 2: Relay_DRV is at a high level, Q1 conducts, the optocoupler U1 is saturated and conducts, Q3 conducts; VCC2 charges the energy storage capacitor C2 and provides current to the base of the switching transistor Q2, causing the switching transistor Q2 to conduct. The gate voltage of the switching transistor Q4 is then pulled down, the switching transistor Q4 conducts, and the voltage of the power supply VCC3 is applied across the relay coil through the switching transistor Q4, causing the relay to be pulled in at a high voltage. Since the voltage of VCC3 is greater than the voltage of VCC4, the diode D2 is reverse - biased and cut off. The relay completes the pull - in until the next stage.
[0020] Stage 3: Relay_DRV is still at a high level. The voltage of the energy storage capacitor C2 is charged up, the current flowing through the base of the switching transistor Q1 gradually drops to 0A, resulting in the switching transistor Q2 being turned off. At the same time, the gate voltage of the switching transistor Q4 is raised, the switching transistor Q4 is turned off. At this time, the diode D2 conducts, and VCC4 supplies power to the relay coil through the diode D2. At this time, the voltage across the relay coil is VCC4. In this stage, the relay is in a low - loss pull - in and holding state.
[0021] Stage 4: Relay_DRV is at a low level, the switching transistor Q1 is turned off, the optocoupler U1 is not conducting, the capacitor C2 discharges through the resistor R6, and after the discharge is completed, the circuit state transitions to Stage 1.
[0022] The above - mentioned solution uses a voltage - dividing drive with optocoupler isolation. Although it can achieve pull - in and holding at a low voltage, has low power consumption and good reliability, at least two power supplies are required to implement the above - mentioned solution. Providing additional power supplies will inevitably bring efficiency problems. In addition, the above - mentioned solution uses a relatively large number of discrete devices, which will lead to an increase in the size of the PCB circuit board and an increase in the required cost.
[0023] As Figure 2 shown, an embodiment of the present application provides a relay drive circuit 100. The relay drive circuit 100 is used to drive the relay 130 to be pulled in or disconnected. The relay drive circuit 100 includes a first power supply terminal 110, a ground terminal 120, a buck module 140, and a switching module 150.
[0024] The first power supply terminal 110 is connected to the first end of the relay 130, and the ground terminal 120 is connected to the second end of the relay 130. The first power supply terminal 110 is used to output a first voltage. The voltage of the ground terminal 120 is usually zero. When the first power supply terminal 110 outputs the first voltage, the voltage across the relay 130 is the first voltage.
[0025] The input end of the buck module 140 is connected to the second end of the relay 130, and the output end of the buck module 140 is connected to the ground terminal 120. The buck module 140 is used to adjust the voltage across the relay 130. The buck module 140 can adjust the voltage across the relay 130 to be the first voltage or the second voltage, and the first voltage is higher than the second voltage. That is to say, the buck module 140 can reduce or keep unchanged the voltage across the relay 130. When the buck module 140 keeps the voltage across the relay 130 unchanged, the voltage across the relay 130 is the first voltage, and the relay 130 can change from the off state to the on state. When the buck module 140 reduces the voltage across the relay 130, the voltage across the relay 130 is the second voltage, and the relay 130 can maintain the on state. The ranges of the first voltage and the second voltage are both related to the specifications of the relay 130. For different specifications of the relay 130, the corresponding ranges of the first voltage and the second voltage may be different.
[0026] The first end of the switch module 150 is connected to the output end of the buck module 140, and the second end of the switch module 150 is connected to the ground terminal 120. The switch module 150 is used to turn on or off the relay drive circuit 100. When the switch module 150 is closed, the relay drive circuit 100 is turned on and the relay 130 works. When the switch module 150 is open, the relay drive circuit 100 is turned off and the relay 130 does not work.
[0027] In summary, in the embodiment of the present application, the voltage across the relay 130 is adjusted by the buck module 140. When the voltage across the relay 130 is the first voltage, the relay 130 has sufficient suction force to change from the off state to the on state, so it has sufficient suction force. When the buck module 140 reduces the voltage across the relay 130 and the voltage across the relay 130 is adjusted to the second voltage, the relay 130 can maintain the on state, thus being more power-saving.
[0028] In addition, since there is only one power supply required in the relay drive circuit 100, compared with Figure 1 the scheme, the relay drive circuit 100 of this embodiment reduces a relay 130 drive power supply, some switching tubes, the diode D1, and devices such as resistors and capacitors. Since the devices required for the relay 130 coil drive circuit are fewer, the cost can be reduced, the single-board size can be reduced, and the power density can be improved.
[0029] Such asFigure 3 As shown, in some embodiments, the buck module 140 includes an energy storage unit 141, a first switch 142, a voltage dividing unit 143, and a discharging unit 144.
[0030] The first end of the energy storage unit 141 is connected to the first power supply terminal 110, and the second end of the energy storage unit 141 is connected to the first end of the switch module 150. When the switch module 150 is disconnected, the first power supply terminal 110 charges the energy storage unit 141, and the energy storage unit 141 is in a charging state.
[0031] The input end of the first switch 142 is connected to the second end of the relay 130, the output end of the first switch 142 is connected to the first end of the switch module 150, and the controlled end of the first switch 142 is connected to the first end of the energy storage unit 141.
[0032] The voltage dividing unit 143 is connected in parallel with the first switch 142. When the first switch 142 is disconnected, the current flows through the voltage dividing unit 143, thereby reducing the voltage across the relay 130.
[0033] The discharging unit 144 is connected in parallel with the energy storage unit 141. After the first switch 142 is closed, the energy storage unit 141 can discharge through the discharging unit 144.
[0034] The on / off of the first switch 142 is related to the pressure difference between the controlled end and the output end. When the switch module 150 is turned on, the output end of the first switch 142 is grounded, and the difference between the controlled end and the output end of the first switch 142 reaches the threshold value, and the first switch 142 closes. The voltage across the relay 130 is the first voltage. At the same time, the energy storage unit 141 starts to discharge. When the voltage at the first end of the energy storage unit 141 drops below the control voltage of the first switch 142, that is, when the difference between the controlled end and the output end of the first switch 142 is lower than the threshold value, the first switch 142 disconnects, and the voltage dividing unit 143 divides the voltage of the relay 130 to adjust the voltage across the relay 130 to the second voltage.
[0035] As Figure 4 shown, in some embodiments, the switch module 150 includes a second switch 151, an optocoupler 152, and a third switch 153.
[0036] The first end of the second switch 151 is connected to the output end of the buck module 140, and the second end of the second switch 151 is connected to the ground terminal 120.
[0037] The light-receiving input end of the optocoupler 152 is connected to the first power supply terminal 110, the light-receiving output end of the optocoupler 152 is connected to the controlled end of the second switch 151, the light-emitting input end of the optocoupler 152 is connected to the second power supply terminal 160, and the light-emitting output end of the optocoupler 152 is connected to the controlled end of the second switch 151.
[0038] The input end of the third switch 153 is connected to the light-emitting output end of the optocoupler 152, and the output end of the third switch 153 is grounded. When the third switch 153 is closed, the light-receiving input end and the light-receiving output end of the optocoupler 152 are conducted, and the second switch 151 is closed. By setting the optocoupler 152, the feedback of the third switch 153 can be transmitted to the second switch 151, and the second switch 151 and the third switch 153 can be kept electrically isolated, improving the stability.
[0039] As Figure 5 shown, in some embodiments, the energy storage unit 141 includes an energy storage capacitor C3, the first switch 142 includes a first switching transistor Q4, the voltage dividing unit 143 includes a first voltage dividing resistor R10, and the discharging unit 144 includes a first current limiting resistor R9.
[0040] The first end of the first current limiting resistor R9 is connected to the first power supply terminal 110, the first end of the energy storage capacitor C3 is connected to the second end of the first current limiting resistor R9 and the controlled end of the switching transistor, the second end of the energy storage capacitor C3 is connected to the first end of the first current limiting resistor R9, the first end of the switching module 150, the output end of the first switching transistor Q4, and the first end of the first voltage dividing resistor R10, and the second end of the first voltage dividing resistor R10 is connected to the input end of the first switching transistor Q4 and the second end of the relay 130.
[0041] As Figure 5 shown, in some embodiments, the buck module 140 further includes a second current limiting resistor R8 and a first filter capacitor C2. The first end of the second current limiting resistor R8 is connected to the second end of the energy storage capacitor C3, and the second end of the second current limiting resistor R8 is connected to the first end of the first current limiting resistor R9. The first end of the first filter capacitor C2 is connected to the first power supply terminal 110, and the second end of the first filter capacitor C2 is connected to the first end of the first current limiting resistor R9. The second current limiting resistor R8 can reduce the current when the energy storage capacitor C3 is charged, and minimize the impact on the energy storage capacitor C3 during charging.
[0042] As Figure 5 shown, in some embodiments, the second switch 151 includes a second switching transistor Q3, a third switching transistor Q2, a third current limiting resistor R5, a second voltage dividing resistor R6, and a third voltage dividing resistor R7.
[0043] The input end of the second switching transistor Q3 is connected to the output end of the buck module 140, and the output end of the second switching transistor Q3 is connected to the ground terminal 120.
[0044] The output end of the third switching transistor Q2 is connected to the controlled end of the second switching transistor Q3, and the input end of the third switching transistor Q2 is connected to the output end of the buck module 140. By setting two switching transistors, the overcurrent capacity can be increased.
[0045] The first end of the third current-limiting resistor R5 is connected to the light-receiving output end of the optocoupler 152, and the second end of the third current-limiting resistor R5 is connected to the controlled end of the third switching transistor Q2. The third current-limiting resistor R5 is used to reduce the current when the second switching transistor Q3 and the third switching transistor Q2 are turned on, thereby reducing power consumption.
[0046] The first end of the second voltage-dividing resistor R6 is connected to the controlled end of the third switching transistor Q2, and the second end of the second voltage-dividing resistor R6 is connected to the ground terminal 120. The second voltage-dividing resistor R6 can protect the third switching transistor Q2.
[0047] The first end of the third voltage-dividing resistor R7 is connected to the controlled end of the second switching transistor Q3, and the second end of the third voltage-dividing resistor R7 is connected to the ground terminal 120. The third voltage-dividing resistor R7 can protect the second switching transistor Q3.
[0048] As Figure 5 shown, in some embodiments, the relay driving circuit 100 further includes a diode D1 and a voltage-regulating diode D2. The positive electrode of the diode D1 is connected to the first end of the first voltage-dividing resistor R10, and the negative electrode of the diode D1 is connected to the first end of the first current-limiting resistor R9. The relay 130 can discharge through the diode D1, and the energy storage capacitor C2 cannot discharge the relay 130.
[0049] The positive electrode of the voltage-regulating diode D2 is connected to the ground terminal 120, and the negative electrode of the voltage-regulating diode D2 is connected to the second end of the energy storage capacitor C3. The voltage-regulating diode D2 can protect the second switching transistor Q3.
[0050] As Figure 5 shown, in some embodiments, the third switch 153 includes a fourth switching transistor Q1, a fourth current-limiting resistor R1, and a fourth voltage-dividing resistor R2.
[0051] The input end of the fourth switching transistor Q1 is connected to the light-emitting output end of the optocoupler 152, and the output end of the fourth switching transistor Q1 is grounded.
[0052] The first end of the fourth current-limiting resistor R1 is connected to the controlled end of the fourth switching transistor Q1, and the second end of the fourth current-limiting resistor R1 is used to input a driving signal.
[0053] The first end of the fourth voltage-dividing resistor R2 is connected to the controlled end of the fourth switching transistor Q1, and the second end of the fourth voltage-dividing resistor R2 is grounded.
[0054] As Figure 5 shown, in some embodiments, the relay driving circuit 100 further includes a fifth current-limiting resistor R3 and a sixth current-limiting resistor R4. The first end of the fifth current-limiting resistor R3 is connected to the second power supply terminal 160, and the second end of the fifth current-limiting resistor R3 is connected to the light-emitting input end of the optocoupler 152. The fifth current-limiting resistor R3 can reduce the power consumption when the optocoupler 152 is turned on.
[0055] The first end of the sixth current-limiting resistor R4 is connected to the light-emitting input end of the optocoupler 152, and the second end of the sixth current-limiting resistor R4 is connected to the light-emitting output end of the optocoupler 152. The sixth current-limiting resistor R4 can reduce the impact on the optocoupler 152 and improve the stability of the optocoupler 152.
[0056] As Figure 5 shown, in some embodiments, the relay drive circuit 100 further includes: a second filter capacitor C4, a third filter capacitor C1, and a fourth filter capacitor C5.
[0057] The first end of the second filter capacitor C4 is connected to the first end of the relay 130, and the second end of the second filter capacitor C4 is grounded. The second filter capacitor C4 can filter the first end of the relay 130, so that the input current at the first end of the relay 130 is relatively stable.
[0058] The first end of the third filter capacitor C1 is connected to the light-receiving input end of the optocoupler 152, and the second end of the second filter capacitor C4 is grounded. The third filter capacitor C1 can filter the light-receiving input end of the optocoupler 152, so that the input current at the light-receiving input end of the optocoupler 152 is relatively stable.
[0059] The first end of the fourth filter capacitor C5 is connected to the second power supply terminal 160, and the second end of the second filter capacitor C4 is grounded. The second filter capacitor C4 can filter the second power supply terminal 160, so that the input current at the light-emitting input end of the optocoupler 152 is relatively stable.
[0060] Next, the Figure 5 working principle will be described.
[0061] Stage 1: When the drive signal input terminal RLY_Drv is at a low level, the fourth switching transistor Q1 is turned off, the optocoupler 152 is not conducting, the back end of the optocoupler 152 is in a high-impedance state, the third switching transistor Q2 and the second switching transistor Q3 are turned off, and the voltage across the coil of the relay 130 is 0V. At this time, the energy storage capacitor C2 is charged through the resistor R8, and finally the voltage of the energy storage capacitor C3 is the pull-in voltage VCC2 of the relay 130, and the first switching transistor Q4 is turned off.
[0062] Stage 2: When the drive signal input terminal RLY_Drv becomes high level, the fourth switching transistor Q1 is turned on, VCC1 makes the optocoupler 152 conduct, the VCC2 at the back end of the optocoupler 152 makes the third switching transistor Q2 conduct through the third current-limiting resistor R5, and then the second switching transistor Q3 also conducts. The S pole of the first switching transistor Q4 is pulled to the ground, a voltage difference is generated between the G and S of the first switching transistor Q4, and the first switching transistor Q4 conducts. At this time, the voltage across the coil of the relay 130 is VCC2.
[0063] Stage 3: When the first switching transistor Q4 is turned on, the voltage across the coil of the relay 130 is VCC2, causing the contacts of the relay 130 to close. At the same time, the energy storage capacitor C2 starts to discharge (the discharge time can be adjusted by changing the capacitance value of the energy storage capacitor C2 and the resistance value of the first current-limiting resistor R9). When the voltage of the energy storage capacitor C2 drops below the threshold voltage of the first switching transistor Q4, the first switching transistor Q4 turns off. At this time, VCC2 is pulled to GND_S through the coil of the relay 130 and the first voltage-dividing resistor R10 (the holding voltage for the relay 130 to remain closed can be adjusted by changing the resistance value of the first voltage-dividing resistor R10), and in this state, the relay 130 remains stably closed.
[0064] Stage 4: When the drive signal input terminal RLY_Drv becomes low level, the first switching transistor Q1 turns off, the optocoupler 152 is not conducting, the back end of the optocoupler 152 is in a high-impedance state, and the third switching transistor Q2 and the second switching transistor Q3 turn off. Since there is a certain inductance in the coil of the relay 130, the inductor current cannot change suddenly, so a discharge loop is formed through the zener diode D1, and the circuit operation transitions to Stage 1.
[0065] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components; in the description of the present application, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the accompanying drawings. This is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the accompanying drawings are only for illustrative purposes and should not be construed as a limitation of the present application. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.
[0066] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included within the protection scope of the present application.
Claims
1. A relay drive circuit, characterized in that: include: A first power supply end, connected to a first end of the relay, the first power supply end being used to output a first voltage; A ground terminal connected to the second terminal of the relay; A step-down module, wherein the input end of the step-down module is connected to the second end of the relay, the output end of the step-down module is connected to the ground end, and the step-down module is used to adjust the voltage across the two ends of the relay; A switch module, wherein a first end of the switch module is connected to the output end of the step-down module, and a second end of the switch module is connected to the ground end; Among them, the step-down module can adjust the voltage across the relay to the first voltage or the second voltage, and the first voltage is higher than the second voltage; when the voltage across the relay is the first voltage, the relay can change from an open state to an engaged state; when the voltage across the relay is the second voltage, the relay can maintain an engaged state.
2. The relay drive circuit according to claim 1, characterized in that: The step-down module comprises: An energy storage unit, wherein a first end of the energy storage unit is connected to the first power supply end, a second end of the energy storage unit is connected to a first end of the switch module, and when the switch module is disconnected, the energy storage unit is in a charging state; a first switch, wherein an input end of the first switch is connected to the second end of the relay, an output end of the first switch is connected to the first end of the switch module, and a controlled end of the first switch is connected to the first end of the energy storage unit; A voltage dividing unit connected in parallel with the first switch; A discharge unit, connected in parallel with the energy storage unit, and the energy storage unit can be discharged through the discharge unit; Among them, when the switch module is turned on, the first switch is closed, and the voltage across the relay is the first voltage; when the energy storage unit is discharged to a voltage at the first end of the energy storage unit that is lower than the control voltage of the first switch, the first switch is disconnected, and the voltage divider unit divides the voltage of the relay to adjust the voltage across the relay to the second voltage.
3. The relay drive circuit according to claim 2, characterized in that: The energy storage unit includes an energy storage capacitor, the first switch includes a first switch tube, the voltage dividing unit includes a first voltage dividing resistor, and the discharge unit includes a first current limiting resistor; The first end of the first current limiting resistor is connected to the first power supply end, the first end of the energy storage capacitor is connected to the second end of the first current limiting resistor and the controlled end of the first switch tube, the second end of the energy storage capacitor is connected to the first end of the first current limiting resistor, the first end of the switch module, the output end of the first switch tube and the first end of the first voltage dividing resistor, and the second end of the first voltage dividing resistor is connected to the input end of the first switch tube and the second end of the relay.
4. The relay drive circuit according to claim 3, characterized in that: The step-down module further includes: a second current limiting resistor, wherein a first end of the second current limiting resistor is connected to a second end of the energy storage capacitor, and a second end of the second current limiting resistor is connected to a first end of the first current limiting resistor; A first filter capacitor, wherein a first end of the first filter capacitor is connected to the first power supply end, and a second end of the first filter capacitor is connected to a first end of the first current limiting resistor.
5. The relay drive circuit according to claim 3, characterized in that: The relay drive circuit also includes: a diode, wherein an anode of the diode is connected to a first end of the first voltage-dividing resistor, and a cathode of the diode is connected to a first end of the first current-limiting resistor; A voltage regulator tube, wherein the positive electrode of the voltage regulator tube is connected to the ground terminal, and the negative electrode of the voltage regulator tube is connected to the second end of the energy storage capacitor.
6. The relay drive circuit according to claim 1, characterized in that: The switch module comprises: a second switch, wherein a first end of the second switch is connected to the output end of the step-down module, and a second end of the second switch is connected to the ground end; An optical coupler, wherein the light receiving input end of the optical coupler is connected to the first power supply end, the light receiving output end of the optical coupler is connected to the controlled end of the second switch, the light emitting input end of the optical coupler is connected to the second power supply end, and the light emitting output end of the optical coupler is connected to the controlled end of the second switch; A third switch, wherein an input end of the third switch is connected to the light-emitting output end of the optical coupler, and an output end of the third switch is grounded; Wherein, when the third switch is closed, the light receiving input end of the optocoupler is connected to the light receiving output end of the optocoupler, and the second switch is closed.
7. The relay drive circuit according to claim 6, characterized in that: The second switch comprises: A second switch tube, wherein an input end of the second switch tube is connected to an output end of the step-down module, and an output end of the second switch tube is connected to the ground end; a third switch tube, wherein the output end of the third switch tube is connected to the controlled end of the second switch tube, and the input end of the third switch tube is connected to the output end of the step-down module; a third current limiting resistor, wherein a first end of the third current limiting resistor is connected to the light receiving output end of the optocoupler, and a second end of the third current limiting resistor is connected to the controlled end of the third switch tube; a second voltage-dividing resistor, wherein a first end of the second voltage-dividing resistor is connected to the controlled end of the third switch tube, and a second end of the second voltage-dividing resistor is connected to the ground end; A third voltage-dividing resistor, wherein a first end of the third voltage-dividing resistor is connected to the controlled end of the second switch tube, and a second end of the third voltage-dividing resistor is connected to the ground end.
8. The relay drive circuit according to claim 6, characterized in that: The third switch comprises: a fourth switch tube, wherein an input end of the fourth switch tube is connected to a light-emitting output end of the optical coupler, and an output end of the fourth switch tube is grounded; a fourth current limiting resistor, wherein a first end of the fourth current limiting resistor is connected to the controlled end of the fourth switch tube, and a second end of the fourth current limiting resistor is used for inputting a driving signal; A fourth voltage-dividing resistor, wherein a first end of the fourth voltage-dividing resistor is connected to the controlled end of the fourth switch tube, and a second end of the fourth voltage-dividing resistor is grounded.
9. The relay driving circuit according to claim 6, characterized in that: The relay drive circuit also includes: a fifth current limiting resistor, wherein a first end of the fifth current limiting resistor is connected to the second power supply end, and a second end of the fifth current limiting resistor is connected to the light-emitting input end of the optocoupler; A sixth current limiting resistor, wherein a first end of the sixth current limiting resistor is connected to the light-emitting input end of the optocoupler, and a second end of the sixth current limiting resistor is connected to the light-emitting output end of the optocoupler.
10. The relay driving circuit according to claim 6, characterized in that: The relay drive circuit also includes: a second filter capacitor, wherein a first end of the second filter capacitor is connected to the first end of the relay, and a second end of the second filter capacitor is grounded; A third filter capacitor, wherein a first end of the third filter capacitor is connected to the light receiving input end of the optical coupler, and a second end of the second filter capacitor is grounded; A fourth filter capacitor, wherein a first end of the fourth filter capacitor is connected to the second power supply end, and a second end of the second filter capacitor is grounded.