Magnetic latching relay driving circuit and electronic equipment

Abstract

The utility model relates to a magnetic latching relay drive circuit and electronic equipment. Comprising a motor driving chip, a controller, a reference voltage generation unit and a power supply unit, a first input end and a second input end of the motor driving chip are correspondingly connected with a first level output pin and a second level output pin of the controller and are used for receiving a first control level and a second control level output by the controller; the reference voltage generation unit is connected with a reference voltage input end of the motor driving chip and is used for generating reference voltage and inputting the reference voltage to the reference voltage input end of the motor driving chip; the power supply unit is connected with the power supply end of the motor driving chip and used for providing power input for the motor driving chip. And the first output end and the second output end of the motor driving chip are correspondingly connected with the first end and the second end of a control coil in the magnetic latching relay. According to the utility model, an accurate time sequence can be provided for the magnetic latching relay, and the risk of damage to the magnetic latching relay is greatly reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to relay drive technical field more specifically, relate to a kind of magnetic latching relay drive circuit and electronic equipment. BACKGROUND

[0002] With the rapid development of new energy electric vehicles, charging pile equipment is also more and more popular. In the working process of the charging pile, the total power is distributed by the power distribution unit to enable each terminal to be fully charged. The traditional power distribution unit is composed of hundreds of high-voltage contactors, which is very expensive and not conducive to cost control. Some power scheduling matrices composed of magnetic latching relays are currently used. However, the magnetic latching relay has two input pins, and the timing requirements for the input of the drive circuit are very high. When the drive timing and drive voltage of the magnetic latching relay are abnormal, the magnetic latching relay may be damaged, and more seriously, it may cause a car fire, which may further cause a fire. Therefore, it is particularly important to ensure the stability and reliability of the magnetic latching relay drive unit in the design of the power distribution matrix. SUMMARY

[0003] The technical problem to be solved by the utility model is to provide a magnetic latching relay drive circuit and electronic equipment to solve the above technical defects of the prior art.

[0004] The utility model adopts the technical scheme to solve the technical problem: a magnetic latching relay drive circuit is constructed, which comprises a motor drive chip, a controller, a reference voltage generation unit, and a power supply unit.

[0005] The first input end of the motor drive chip is connected to the first level output pin of the controller for receiving the first control level output by the controller.

[0006] The second input end of the motor drive chip is connected to the second level output pin of the controller for receiving the second control level output by the controller.

[0007] The reference voltage generation unit is connected to the reference voltage input end of the motor drive chip for generating a reference voltage and inputting it to the reference voltage input end of the motor drive chip.

[0008] The power supply unit is connected to the power supply end of the motor drive chip for providing power input to the motor drive chip.

[0009] The first output end of the motor drive chip is connected to the first end of the control coil in the magnetic latching relay, and the second output end of the motor drive chip is connected to the second end of the control coil in the magnetic latching relay.

[0010] Preferably, the relay state feedback unit is further connected with the controller.

[0011] The input end of the relay state feedback unit is connected with the first power supply voltage through the auxiliary contact of the magnetic latching relay.

[0012] The output end of the relay state feedback unit is connected with the controller, and is used for outputting a state level signal to the controller according to the on or off state of the magnetic latching relay.

[0013] Preferably, the relay state feedback unit comprises a triode, a first resistor, a second resistor, a third resistor, a first capacitor and a second capacitor.

[0014] The first end of the first resistor is connected with the second power supply voltage, and the second end of the first resistor is connected with the signal receiving pin of the controller, the first end of the first capacitor and the collector of the triode.

[0015] The base of the triode is connected with the first end of the second resistor, the first end of the second capacitor and the first end of the third resistor, the second end of the third resistor is connected with the first end of the auxiliary contact of the magnetic latching relay, and the second end of the auxiliary contact of the magnetic latching relay is connected with the first power supply voltage.

[0016] The second end of the first capacitor, the emitter of the triode, the second end of the second resistor and the second end of the second capacitor are grounded.

[0017] Preferably, the relay state feedback unit further comprises a first voltage conversion chip.

[0018] The input end of the first voltage conversion chip is connected with the output end of the reference voltage generation unit, and the output end of the first voltage conversion chip outputs the second power supply voltage.

[0019] Preferably, the reference voltage generation unit comprises a second voltage conversion chip, and a third capacitor, a fourth resistor, a fifth resistor and an inductor.

[0020] The input pin and the enable pin of the second voltage conversion chip are connected with the first power supply voltage, the self-boosting pin of the second voltage conversion chip is connected with the first end of the third capacitor, and the output pin of the second voltage conversion chip is connected with the second end of the third capacitor and the first end of the inductor.

[0021] The second end of the inductor is connected with the first end of the fourth resistor and a reference voltage input end of the motor driving chip;

[0022] The second end of the fourth resistor is connected with an output voltage feedback pin of the second voltage conversion chip and the first end of the fifth resistor, and the second end of the fifth resistor is grounded.

[0023] Preferably, in the magnetic latching relay driving circuit embodiment of the utility model, the reference voltage generating unit further comprises a first filter circuit and a second filter circuit;

[0024] The first end of the first filter circuit is connected with an input pin and an enable pin of the second voltage conversion chip, and the second end of the first filter circuit is grounded;

[0025] The first end of the second filter circuit is connected with the second end of the inductor, and the second end of the second filter circuit is grounded.

[0026] Preferably, in the magnetic latching relay driving circuit embodiment of the utility model, the power supply unit comprises a first connector and a third filter circuit;

[0027] The first connector is used for connecting an external power input to provide a first power supply voltage;

[0028] The second pin of the first connector is connected with the first end of the third filter circuit and a power supply end of the motor driving chip, and the second pin of the first connector and the second end of the third filter circuit are grounded.

[0029] Preferably, in the magnetic latching relay driving circuit embodiment of the utility model, a first current limiting resistor and a second current limiting resistor are further included;

[0030] The first input end of the motor driving chip is connected with a first level output pin of the controller through the first current limiting resistor;

[0031] The second input end of the motor driving chip is connected with a second level output pin of the controller through the second current limiting resistor.

[0032] Preferably, in the magnetic latching relay driving circuit embodiment of the utility model, the model of the motor driving chip is DRV8870.

[0033] The utility model further provides an electronic equipment, include, magnetic latching relay and as above described magnetic latching relay driving circuit, wherein, the magnetic latching relay driving circuit is used for driving the magnetic latching relay works.

[0034] The utility model discloses a magnetic latching relay drive circuit and electronic equipment, have following beneficial effect: utilize motor drive chip output to drive magnetic latching relay, can provide accurate timing for magnetic latching relay, greatly reduced the risk of magnetic latching relay damage. BRIEF DESCRIPTION OF DRAWINGS

[0035] The utility model will be further explained in connection with the drawings and examples, on the drawings, the utility model has the following beneficial effect:

[0036] Figure 1 It is a structure schematic diagram of one embodiment of the utility model magnetic latching relay drive circuit;

[0037] Figure 2 It is the structure schematic diagram of another embodiment of the utility model magnetic latching relay drive circuit;

[0038] Figure 3 It is the local circuit schematic diagram of one embodiment of the utility model magnetic latching relay drive circuit;

[0039] Figure 4 It is the local circuit schematic diagram of another embodiment of the utility model magnetic latching relay drive circuit;

[0040] Figure 5 It is the local circuit schematic diagram of another embodiment of the utility model magnetic latching relay drive circuit. DETAILED DESCRIPTION

[0041] In order to have more clear understanding to the technical features, the object and the effect of the utility model, now the specific implementation of the utility model is explained in detail with the drawings.

[0042] As Figure 1 Shown, show one embodiment of the utility model magnetic latching relay drive circuit.In Figure 1The utility model discloses a kind of magnetic latching relay drive circuits of the embodiment of the utility model shown, including: motor drive chip U1, controller 110, reference voltage generating unit 130 and power supply unit 120;The first input end of motor drive chip U1 is connected with the first level output pin of controller 110, for receiving the first control level output by controller 110;The second input end of motor drive chip U1 is connected with the second level output pin of controller 110, for receiving the second control level output by controller 110;Reference voltage generating unit 130 is connected with the reference voltage input end of motor drive chip U1, for generating reference voltage and input to the reference voltage input end of motor drive chip U1;Power supply unit 120 is connected with the power supply end of motor drive chip U1, for providing power supply input to motor drive chip U1;The first output end of motor drive chip U1 is connected with the first end of control coil in magnetic latching relay K1, and the second output end of motor drive chip U1 is connected with the second end of control coil in magnetic latching relay K1.

[0043] Specifically, when magnetic latching relay drive circuit works, motor drive chip U1 adjusts the output level of the first output end and the second output end of motor drive chip U1 according to the received first control level and second control level, and then controls the power-on process of the control coil of magnetic latching relay K1, to realize the conduction or disconnection of magnetic latching relay K1. Figure 5 As shown, controller 110 can include MCU chip U3B. The first level output pin and the second level output pin of controller 110 are used to output first control level and second control level respectively. The input and output level logic relationship of motor drive chip U1 is a priori relationship, that is, when the model of motor drive chip U1 is known, the level relationship between the first input end and the second input end of motor drive chip U1 and the first output end and the second output end of motor drive chip U1 is also known. In a specific embodiment, the model of motor drive chip U1 is DRV8870. When the first input end and the second input end of this motor drive chip U1 are both low level, the first output end and the second output end are both high level; when the first input end is high level and the second input end is low level, the first output end gets output voltage according to the input voltage of the power supply end of motor drive chip U1, and the second output end has no voltage output; when the first input end is low level and the second input end is high level, the first output end has no voltage output, and the second output end gets output voltage according to the input voltage of the power supply end of motor drive chip U1; when the first input end and the second input end are both high level, the first output end and the second output end have no voltage output.

[0044] In the working process of the magnetic latching relay driving circuit, the first control level and the second control level output by the controller 110 can be logic levels that last for a preset time length. That is, the time length of the first control level and the second control level maintains the output level signals of the first output end and the second output end of the motor driving chip U1. At the same time, in order to enable the magnetic latching relay driving circuit to normally drive the magnetic latching relay K1, the logic levels of the first control level and the second control level need to be opposite, so that the first output end of the motor driving chip U1 and the second output end of the motor driving chip U1 can form a normal voltage difference, thereby electrifying the control coil in the magnetic latching relay K1, so that the working contact of the magnetic latching relay K1 normally works. The logic relationship of the first control level and the second control level can also be switched, so that the voltage difference direction of the first output end of the motor driving chip U1 and the second output end of the motor driving chip U1 changes, thereby changing the electrification of the control coil in the magnetic latching relay, so that the main contact in the magnetic latching relay realizes switching between conduction and shutdown. In a specific embodiment, when the first control level is a logic 1 level, the second control level is set to a logic 0 level; when the first control level is a logic 0 level, the second control level is set to a logic 1 level.

[0045] In a specific embodiment, as shown in Figure 3 , the input voltage of the power supply end of the motor driving chip U1 is 12V. The first control level (corresponding to the MCU_RLY1 signal in Figure 3 ) output by the controller 110 is a logic 1 level that lasts for 200ms, and the second control level (corresponding to the MCU_RLY2 signal in Figure 3 ) output by the controller 110 is a logic 0 level that lasts for 200ms. The first output end (corresponding to the OUT1 pin in Figure 3 ) of the motor driving chip U1 and the second output end (corresponding to the OUT2 pin in Figure 3 ) of the motor driving chip U1 respectively output driving levels of 12V and 0V, and maintain 200ms. The driving levels are used to drive the magnetic latching relay K1 to close. When the first control level (corresponding to the MCU_RLY1 signal in Figure 3 ) output by the controller 110 is a logic 0 level that lasts for 200ms, and the second control level (corresponding to the MCU_RLY2 signal in Figure 1 ) output by the controller 110 is a logic 1 level that lasts for 200ms, the first output end (corresponding to the OUT1 pin in Figure 3 ) of the motor driving chip U1 and the second output end (corresponding to the OUT2 pin in Figure 3The MCU_RLY1 and MCU_RLY2 signals output 0V and 12V driving levels respectively, and keep 200ms, which are used to drive the magnetic latching relay K1 to be disconnected. In addition, when the MCU_RLY1 and MCU_RLY2 signals output logic 0 levels or logic 1 levels at the same time, the first output end and the second output end of the motor driving chip U1 have no driving capability, which means that the magnetic latching relay K1 has no input driving capability, so that the magnetic latching relay K1 is prevented from abnormally operating when the input is abnormal, and the stability is improved.

[0046] As shown in Figure 2 In an embodiment, the magnetic latching relay driving circuit further comprises a relay state feedback unit 140. The input end of the relay state feedback unit 140 is connected to the first power supply voltage through the auxiliary contact of the magnetic latching relay K1. The output end of the relay state feedback unit 140 is connected to the controller 110, and is used to output a state level signal to the controller 110 according to the on or off state of the magnetic latching relay K1. The auxiliary contact of the magnetic latching relay K1 has the same state as the main contact of the magnetic latching relay K1. The working contact of the magnetic latching relay K1 can only include the main contact of the magnetic latching relay K1, or can include both the auxiliary contact of the magnetic latching relay K1 and the main contact of the magnetic latching relay K1, that is, the driving circuit can control the auxiliary contact of the magnetic latching relay K1 and the main contact of the magnetic latching relay K1 to be in the on or off state at the same time. When the main contact of the magnetic latching relay K1 is on, that is, the magnetic latching relay K1 is in the on state, the auxiliary contact of the magnetic latching relay K1 is also on. At this time, the relay state feedback unit 140 outputs a corresponding state level signal to the controller 110 to indicate that the magnetic latching relay K1 is in the on state. When the main contact of the magnetic latching relay K1 is off, that is, the magnetic latching relay K1 is in the off state, the auxiliary contact of the magnetic latching relay K1 is also off. At this time, the relay state feedback unit 140 outputs a corresponding state level signal to the controller 110 to indicate that the magnetic latching relay K1 is in the off state.

[0047] Optionally, as shown in Figure 3 The relay state feedback unit 140 comprises a triode, a first resistor, a second resistor, a third resistor, a first capacitor and a second capacitor. The first end of the first resistor is connected to the second power supply voltage, the second end of the first resistor is connected to the signal receiving pin of the controller 110, the first end of the first capacitor and the collector of the triode. The base of the triode is connected to the first end of the second resistor, the first end of the second capacitor and the first end of the third resistor. The second end of the third resistor is connected to the first end of the auxiliary contact of the magnetic latching relay. The second end of the auxiliary contact of the magnetic latching relay is connected to the first power supply voltage. The second end of the first capacitor, the emitter of the triode, the second end of the second resistor and the second end of the second capacitor are grounded.

[0048] In a specific embodiment, the first capacitor includes capacitor C25, the second capacitor includes capacitor C26, the first resistor includes resistor R10, the second resistor includes resistor R12, the third resistor includes resistor R11, and the triode includes triode Q5. The auxiliary contacts of the magnetic latching relay K1 correspond to the fifth and sixth pins of the magnetic latching relay K1, where the fifth pin of the magnetic latching relay K1 is used to connect to the first supply voltage, which corresponds to a 12V voltage in a specific embodiment. When the magnetic latching relay K1 is turned on, its fifth and sixth pins are turned on, and the first supply voltage is input to the base of the triode Q5 through the turned-on contacts and resistor R11. The triode Q5 is turned on, and the collector level of the triode Q5 is pulled down. The controller 110 receives a low-level signal (corresponding to Figure 3 where MCU_DI is a low-level signal). When the magnetic latching relay K1 is turned off, its fifth and sixth pins are turned off, and no voltage is input to the base of the triode Q5 through resistor R11. The triode Q5 is turned off, and the collector level of the triode Q5 is raised by the second supply voltage. The controller 110 receives a high-level signal (corresponding to Figure 3 where MCU_DI is a high-level signal). The controller 110 can obtain the state of the magnetic latching relay K1 by receiving the high and low-level signals.

[0049] Optionally, the relay state feedback unit 140 further includes a first voltage conversion chip; the input end of the first voltage conversion chip is connected to the output end of the reference voltage generation unit 130, and the output end of the first voltage conversion chip outputs the second supply voltage. That is, the output of the reference voltage generation unit 130 is voltage-converted by the first voltage conversion chip to obtain the second supply voltage required by the relay state feedback unit 140. As Figure 4 shown, the first voltage conversion chip includes voltage conversion chip U4 and its peripheral circuit. The output of the reference voltage generation unit 130 is input to the input end of the voltage conversion chip U4 after passing through the filter circuit in the peripheral circuit. After the voltage conversion chip U4 performs voltage conversion, the second supply voltage is output at the output end of the voltage conversion chip U4. In a specific embodiment, the second supply voltage is 3.3V. The second supply voltage is filtered by the filter circuit in the peripheral circuit and then connected to the first end of the resistor R10. Among them, the filter circuit can be composed of one or more capacitors.

[0050] In one embodiment, the reference voltage generation unit 130 includes a second voltage conversion chip, a third capacitor, a fourth resistor, a fifth resistor, and an inductor; the input pin and enable pin of the second voltage conversion chip are connected to a first supply voltage, the self-boosting pin of the second voltage conversion chip is connected to the first terminal of the third capacitor, and the output pin of the second voltage conversion chip is connected to the second terminal of the third capacitor and the first terminal of the inductor; the second terminal of the inductor is connected to the first terminal of the fourth resistor and the reference voltage input terminal of the motor drive chip U1; the second terminal of the fourth resistor is connected to the output voltage feedback pin of the second voltage conversion chip and the first terminal of the fifth resistor, and the second terminal of the fifth resistor is grounded.

[0051] In one specific embodiment, such as Figure 4 As shown, the second voltage conversion chip includes voltage conversion chip U2, the third capacitor includes capacitor C5, the fourth resistor includes resistor R3, the fifth resistor includes resistor R4, and the inductor is inductor L1. Voltage conversion chip U4 and its peripheral circuitry are used to convert the first supply voltage to obtain the reference voltage required by the motor drive chip U1. In one specific embodiment, this reference voltage is 5V.

[0052] Furthermore, the reference voltage generation unit 130 also includes a first filter circuit and a second filter circuit; the first terminal of the first filter circuit is connected to the input pin and enable pin of the second voltage conversion chip, and the second terminal of the first filter circuit is grounded; the first terminal of the second filter circuit is connected to the second terminal of an inductor, and the second terminal of the second filter circuit is grounded. That is, a first filter circuit and a second filter circuit are respectively provided at the input and output terminals of the voltage conversion chip U2 to perform input voltage filtering and output voltage filtering respectively. Figure 4 As shown, in one specific embodiment, the first filter circuit includes a filter circuit composed of capacitors C7 and C8. The first terminals of capacitors C7 and C8 are connected to the input pin and enable pin of the voltage conversion chip U2, respectively, and the second terminals of capacitors C7 and C8 are grounded. In another specific embodiment, the second filter circuit includes a filter circuit composed of capacitors C9 and C10. Capacitor C10 can be an electrolytic capacitor. The first terminal of capacitor C9 and the positive terminal of capacitor C10 are connected to the second terminal of inductor L1 and the reference voltage input terminal of the motor drive chip U1, and the second terminal of capacitor C9 and the negative terminal of capacitor C10 are grounded. In one specific embodiment, as... Figure 3 As shown, the second filter circuit also includes a capacitor C1. The first end of the capacitor C1 is connected to the reference voltage input terminal of the motor drive chip U1, and the second end of the capacitor C1 is grounded.

[0053] In one embodiment, the power supply unit 120 includes a first connector and a third filter circuit; the first connector is used to connect to an external power input to provide a first power supply voltage, the second pin of the first connector is connected to the first terminal of the third filter circuit and the power supply terminal of the motor drive chip U1, and the second pin of the first connector and the second terminal of the third filter circuit are grounded. Figure 4 As shown, in one specific embodiment, the first connector includes connector J2. An external power input is input to the power supply terminal of the motor drive chip U1 through connector J2. The external power input can be a first supply voltage, which is filtered by a third filter circuit before entering the motor drive chip U1. In one specific embodiment, the third filter circuit includes capacitors C2 and C3, which can be electrolytic capacitors. The positive terminals of capacitors C2 and C3 are connected to the power supply terminal of the motor drive chip U1, and the negative terminals of capacitors C2 and C3 are grounded. Capacitors C2 and C3 filter and store energy for the power supply to the motor drive chip U1.

[0054] Optionally, in an embodiment of the magnetic latching relay drive circuit of this utility model, a first current-limiting resistor and a second current-limiting resistor are further included; the first input terminal of the motor drive chip U1 is connected to the first level output pin of the controller 110 through the first current-limiting resistor; the second input terminal of the motor drive chip U1 is connected to the second level output pin of the controller 110 through the second current-limiting resistor. In a specific embodiment, the first current-limiting resistor includes resistor R1, and the second current-limiting resistor includes resistor R2, that is, the output of the controller 110 is input to the input terminal of the motor drive chip U1 through the current-limiting resistors R1 and R2 respectively.

[0055] In one specific embodiment, the electronic device provided by this utility model includes a magnetic latching relay and a magnetic latching relay driving circuit as described above. The magnetic latching relay driving circuit drives the magnetic latching relay to operate. That is, during the operation of the electronic device, the magnetic latching relay is driven to operate by the magnetic latching relay driving circuit. In another specific embodiment, the electronic device is a charging pile or a power distribution device for a charging pile. During the operation of the charging pile, the internal power distribution control process of the charging pile is realized through the aforementioned electronic device. This ensures the stability of the entire charging pile system, reduces product maintenance costs, and enhances product competitiveness.

[0056] It is understood that the above embodiments only illustrate preferred embodiments of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present utility model patent. It should be noted that for those skilled in the art, the above technical features can be freely combined, and several modifications and improvements can be made without departing from the concept of the present utility model, all of which fall within the protection scope of the present utility model. Therefore, all equivalent transformations and modifications made within the scope of the claims of the present utility model should fall within the coverage of the claims of the present utility model.

Claims

1. A magnetic latching relay drive circuit, characterized in that, include: Motor drive chip, controller, reference voltage generation unit, and power supply unit; The first input terminal of the motor drive chip is connected to the first level output pin of the controller, and is used to receive the first control level output by the controller. The second input terminal of the motor drive chip is connected to the second level output pin of the controller, and is used to receive the second control level output by the controller. The reference voltage generation unit is connected to the reference voltage input terminal of the motor drive chip and is used to generate a reference voltage and input it to the reference voltage input terminal of the motor drive chip. The power supply unit is connected to the power supply terminal of the motor driver chip and is used to provide power input to the motor driver chip. The first output terminal of the motor drive chip is connected to the first terminal of the control coil in the magnetic latching relay, and the second output terminal of the motor drive chip is connected to the second terminal of the control coil in the magnetic latching relay.

2. The magnetic latching relay drive circuit according to claim 1, characterized in that, It also includes a relay status feedback unit; The input terminal of the relay status feedback unit is connected to the first power supply voltage through the auxiliary contact of the magnetic latching relay; The output terminal of the relay status feedback unit is connected to the controller and is used to output a status level signal to the controller according to the on or off state of the magnetic latching relay.

3. The magnetic latching relay drive circuit according to claim 2, characterized in that, The relay status feedback unit includes a transistor, a first resistor, a second resistor, a third resistor, a first capacitor, and a second capacitor; The first end of the first resistor is connected to the second power supply voltage, and the second end of the first resistor is connected to the signal receiving pin of the controller, the first end of the first capacitor, and the collector of the transistor. The base of the transistor is connected to the first end of the second resistor, the first end of the second capacitor, and the first end of the third resistor. The second end of the third resistor is connected to the first end of the auxiliary contact of the magnetic latching relay. The second end of the auxiliary contact of the magnetic latching relay is connected to the first power supply voltage. The second terminal of the first capacitor, the emitter of the transistor, the second terminal of the second resistor, and the second terminal of the second capacitor are grounded.

4. The magnetic latching relay drive circuit according to claim 3, characterized in that, The relay status feedback unit also includes a first voltage conversion chip; The input terminal of the first voltage conversion chip is connected to the output terminal of the reference voltage generation unit, and the output terminal of the first voltage conversion chip outputs the second supply voltage.

5. The magnetic latching relay drive circuit according to claim 1, characterized in that, The reference voltage generation unit includes a second voltage conversion chip, a third capacitor, a fourth resistor, a fifth resistor, and an inductor. The input and enable pins of the second voltage conversion chip are connected to the first power supply voltage, the boost pin of the second voltage conversion chip is connected to the first terminal of the third capacitor, and the output pin of the second voltage conversion chip is connected to the second terminal of the third capacitor and the first terminal of the inductor. The second end of the inductor is connected to the first end of the fourth resistor and the reference voltage input terminal of the motor drive chip; The second end of the fourth resistor is connected to the output voltage feedback pin of the second voltage conversion chip and the first end of the fifth resistor, and the second end of the fifth resistor is grounded.

6. The magnetic latching relay drive circuit according to claim 5, characterized in that, The reference voltage generation unit further includes a first filter circuit and a second filter circuit. The first terminal of the first filter circuit is connected to the input pin and the enable pin of the second voltage conversion chip, and the second terminal of the first filter circuit is grounded. The first terminal of the second filter circuit is connected to the second terminal of the inductor, and the second terminal of the second filter circuit is grounded.

7. The magnetic latching relay drive circuit according to claim 1, characterized in that, The power supply unit includes a first connector and a third filter circuit; The first connector is used to connect an external power input to provide a first power supply voltage; The second pin of the first connector is connected to the first end of the third filter circuit and the power supply terminal of the motor drive chip, and the second pin of the first connector and the second end of the third filter circuit are grounded.

8. The magnetic latching relay drive circuit according to claim 1, characterized in that, It also includes a first current-limiting resistor and a second current-limiting resistor; The first input terminal of the motor drive chip is connected to the first level output pin of the controller through the first current limiting resistor. The second input terminal of the motor drive chip is connected to the second level output pin of the controller through the second current-limiting resistor.

9. The magnetic latching relay drive circuit according to claim 1, characterized in that, The motor driver chip is model DRV8870.

10. An electronic device, characterized in that, include: A magnetic latching relay and a magnetic latching relay driving circuit as described in any one of claims 1 to 9, wherein the magnetic latching relay driving circuit is used to drive the magnetic latching relay to work.

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