Control circuit of electromagnetic valve and microwave oven

Abstract

The utility model relates to the technical field of electronic circuits, in particular to a control circuit of an electromagnetic valve and a microwave oven, and the control circuit comprises a starting power supply, a maintaining power supply, a first switch module and a second switch module, when the first switch module is switched on, the second switch module is switched off; when the first switch module is switched off, the second switch module is switched on. According to the embodiment of the utility model, two power supplies are adopted, namely, the starting power supply is adopted during locking, the starting power supply can supply power to the coil according to the rated voltage of the electromagnetic valve, and when the locking state is maintained, the maintaining power supply with lower voltage is adopted, so that the electromagnetic valve can be maintained to be locked without higher voltage; therefore, the power consumption of the electromagnetic valve in the locking state can be reduced, the temperature rise of the coil is reduced, and the service life of the electromagnetic valve is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic circuits, in particular to a control circuit of a solenoid valve and a microwave oven. Background Art

[0002] At present, commonly used cooking appliances such as electric ovens, microwave ovens, steam ovens, etc. usually have electronic locks on the doors. The electronic locks are locked and unlocked by electromagnetic valves, thus forming a double lock with the mechanical lock to ensure the safety of users. Generally, the electromagnetic valve is composed of a single coil. Supplying power to the coil can control the on and off of the electromagnetic valve, thereby achieving locking and unlocking.

[0003] The traditional power-on scheme of the solenoid valve is to continuously supply power to the coil according to the rated voltage of the solenoid valve to keep the top rod of the solenoid valve in the extended state. Since the coil of the solenoid valve is continuously supplied with power at the rated voltage, the temperature of the coil will increase, which will easily affect the service life of the solenoid valve. Utility Model Content

[0004] In view of this, the utility model provides a control circuit of a solenoid valve and a microwave oven to solve the problem that the service life of the solenoid valve is affected by continuously supplying power to the coil of the solenoid valve at a rated voltage.

[0005] In a first aspect, the utility model provides a control circuit of a solenoid valve, the control circuit comprising:

[0006] The starting power supply is used to provide an initial driving voltage to switch the solenoid valve to a locked state;

[0007] A maintaining power supply, used for providing a maintaining driving voltage to keep the solenoid valve in the locked state; the voltage of the maintaining power supply is lower than the voltage of the starting power supply;

[0008] a first switch module, wherein a control end of the first switch module is adapted to receive a first control signal, a first connection end of the first switch module is connected to the start power supply, a second connection end of the first switch module is connected to a first end of the coil of the solenoid valve, and a second end of the coil is grounded via a third switch module;

[0009] a second switch module, wherein a control end of the second switch module is connected to a second connection end of the first switch module, a first connection end of the second switch module is connected to the maintenance power supply, and a second connection end of the second switch module is connected to one end of the solenoid valve coil;

[0010] When the third switch module is turned on, the first switch module is turned on, the second switch module is turned off, and the startup power supply supplies power to the coil; or, when the third switch module is turned on, the first switch module is turned off, the second switch module is turned on, and the maintenance power supply supplies power to the coil.

[0011] Beneficial effect: The embodiment of the utility model adopts two power supplies, that is, the starting power supply is used when locking, and the starting power supply can supply power to the coil according to the rated voltage of the solenoid valve. When maintaining the locked state, a maintenance power supply with a lower voltage is used. As long as the solenoid valve can be kept locked, no large voltage is required, thereby reducing the power consumption of the solenoid valve when maintaining the locked state, reducing the temperature rise of the coil, and ensuring the service life of the solenoid valve. In addition, since the control end of the second switch module is connected to the second connection end of the first switch module, the conduction state of the second switch module is closely related to the first switch module, that is, the entire control circuit only needs one control signal to operate, and no multiple control signals are required, thereby avoiding the situation where it cannot work when multiple control signals fail. At the same time, when the solenoid valve is not in use, the starting power supply and the maintenance power supply can be directly turned off, so that the solenoid valve can be completely turned off. On this basis, a certain amount of electrical energy resources can be saved.

[0012] In an optional implementation, the first switch module includes:

[0013] a first switch tube, wherein a control end of the first switch tube is suitable for receiving the first control signal, a first connection end of the first switch tube is grounded, and a second connection end of the first switch tube is sequentially connected in series with a first resistor, a second resistor, and the startup power supply;

[0014] A second switch tube, wherein the control end of the second switch tube is connected between the first resistor and the second resistor, the first connection end of the second switch is connected to the starting power supply, and the second connection end of the second switch is connected to the first end of the coil.

[0015] In an optional implementation, the first switch tube is an N-type transistor, and the second switch tube is a P-type transistor. The first switch tube and the second switch tube may also be corresponding MOS tubes.

[0016] In an optional implementation, the first switch module further includes:

[0017] A first input resistor, one end of the first input resistor is connected to the control end of the first switch tube, and the other end of the first input resistor is suitable for receiving the first control signal.

[0018] In an optional implementation, the second switch module includes:

[0019] a third switch tube, wherein a control end of the third switch tube is connected to the second connection end of the first switch module through a fourth resistor;

[0020] a fifth resistor, one end of the fifth resistor is connected to the control end of the third switch, and the other end of the fifth resistor is grounded.

[0021] In an optional implementation, the third switch tube is a P-type transistor. The third switch tube may also be a corresponding MOS tube.

[0022] In an optional implementation, the control circuit further includes:

[0023] A freewheeling diode, wherein a cathode of the freewheeling diode is connected to a first end of the coil, and an anode of the freewheeling diode is connected to a second end of the coil.

[0024] Beneficial effects: The embodiment of the utility model can provide a low-impedance freewheeling path for the coil when the solenoid valve is powered off by setting a freewheeling diode, so that the magnetic field energy can be released smoothly. In this process, the freewheeling diode can suppress the reverse electromotive force, and the forward conduction characteristic of the freewheeling diode allows it to open quickly when the induced electromotive force is greater than its forward conduction voltage, forming a freewheeling channel. In this way, the reverse electromotive force is clamped within the forward voltage drop range of the diode, effectively preventing the generation of high voltage spikes. In addition, through the freewheeling diode, the energy stored in the inductor is gradually consumed in the forward voltage drop of the freewheeling diode and the resistance of the coil itself with a smaller current, avoiding arc discharge and severe mechanical vibration. At the same time, the smooth current change can significantly reduce the generation of electromagnetic interference, which helps to improve the electromagnetic compatibility of the entire system. Furthermore, since the diode bears most of the reverse electromotive force, other components in the control circuit are no longer subjected to high voltage shocks, thereby being protected and extending their service life.

[0025] In an optional implementation, the control circuit further includes:

[0026] A third switch module, wherein a control end of the third switch module is adapted to receive a second control signal, a first connection end of the third switch module is connected to the second end of the coil, and a second connection end of the third switch module is grounded.

[0027] Beneficial effect: By setting the third switch module, the embodiment of the utility model can directly switch the third switch module from the on state to the off state when the solenoid valve is not needed. This is simple and convenient, and there is no need to operate the starting power supply and the maintaining power supply, thus reducing the operation process.

[0028] In an optional implementation, the third switch module includes:

[0029] a second input resistor, a first end of the second input resistor receiving the second control signal;

[0030] A fourth switch tube, wherein a control end of the fourth switch tube is connected to the second end of the second input resistor, a first connection end of the fourth switch tube is connected to the second end of the coil, and a second connection end of the fourth switch tube is grounded.

[0031] In a second aspect, the utility model further provides a microwave oven, the microwave oven comprising:

[0032] A box body, wherein a cooking cavity is provided;

[0033] A door body is rotatably arranged on the box body; a door lock is arranged on the door body, and the door lock is suitable for being locked in the lock hole of the box body;

[0034] The lock core of the door lock is locked and unlocked by a solenoid valve, and the solenoid valve uses a control circuit of the solenoid valve as described in any of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the related technologies, the drawings required for use in the specific implementation methods or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0036] Figure 1 The figure is a schematic diagram of a control circuit of a solenoid valve according to an embodiment of the utility model.

[0037] Description of reference numerals:

[0038] 1. First switch module; 11. First switch tube; 12. Second switch tube; 13. First resistor; 14. Second resistor; 15. First input resistor;

[0039] 2. Second switch module; 21. Third switch tube; 22. Fourth resistor; 23. Fifth resistor;

[0040] 3. Coil;

[0041] 4. third switch module; 41. second input resistor; 42. fourth switch tube;

[0042] 5. Freewheeling diode; VDD, startup power supply; VCC, maintenance power supply; IO1, first control signal; IO2, second control signal. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0044] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention 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, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0045] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components, it can be a wireless connection, or it can be a wired connection. For ordinary workers in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0046] At present, commonly used cooking appliances such as electric ovens, microwave ovens, steam ovens, etc., are usually equipped with electronic locks on the door. The electronic lock is a solenoid valve that realizes the functions of locking and unlocking, thereby forming a double lock door with the mechanical lock to ensure the safety of users. In general, the solenoid valve is composed of a single coil 3. Powering the coil 3 can control the on and off of the solenoid valve, thereby realizing locking and unlocking. The traditional power-on scheme of the solenoid valve is to continuously power the coil 3 according to the rated voltage of the solenoid valve to keep the top rod of the solenoid valve in an extended state. Since the coil 3 of the solenoid valve is continuously powered at the rated voltage, the temperature of the coil 3 will increase, which is easy to affect the service life of the solenoid valve.

[0047] In view of this, the utility model provides a control circuit of a solenoid valve and a microwave oven to solve the problem that the service life of the solenoid valve is affected by continuously supplying power to the coil 3 of the solenoid valve at a rated voltage.

[0048] Combine the following Figure 1 , describing an embodiment of the utility model.

[0049] According to an embodiment of the present utility model, on one hand, a control circuit of a solenoid valve is provided, the control circuit comprising a starting power supply VDD, a maintaining power supply VCC, a first switch module 1, a second switch module 2 and a coil 3 of the solenoid valve.

[0050] Specifically, in this embodiment, the startup power supply VDD is used to provide an initial driving voltage to switch the solenoid valve to a locked state. The startup power supply VDD can use the rated voltage of the solenoid valve to power the coil 3 to ensure that the coil 3 can normally generate the magnetic force required by the solenoid valve.

[0051] Furthermore, in this embodiment, the maintenance power supply VCC is used to provide a maintenance driving voltage to maintain the solenoid valve in the locked state. The voltage of the maintenance power supply VCC is less than the voltage of the start-up power supply VDD, as long as the coil 3 can maintain a certain magnetic force. The start-up power supply VDD can use a 12V power supply, and the maintenance power supply VCC can use a 5V power supply.

[0052] Furthermore, in this embodiment, the control end of the first switch module 1 is suitable for receiving a first control signal IO1, the first connection end of the first switch module 1 is connected to the starting power supply VDD, the second connection end of the first switch module 1 is connected to the first end of the coil 3 of the solenoid valve, and the second end of the coil 3 is grounded through the third switch module 4.

[0053] For the working process of the first switch module 1, for example, the third switch module 4 is kept turned on. When the control end of the first switch module 1 receives the first control signal IO1, the first connection end of the first switch module 1 is turned on with the second connection end of the first switch module 1, so that the starting power supply VDD can normally supply power to the coil 3, the coil 3 generates magnetic force, and the solenoid valve works normally; when the control end of the first switch module 1 does not receive the first control signal IO1, the first connection end of the first switch module 1 and the second connection end of the first switch module 1 are cut off, so that the starting power supply VDD cannot supply power to the coil 3, the coil 3 cannot generate magnetic force, and the solenoid valve does not work.

[0054] Furthermore, in this embodiment, the control end of the second switch module 2 is connected to the second connection end of the first switch module 1, the first connection end of the second switch module 2 is connected to the maintenance power supply VCC, and the second connection end of the second switch module 2 is connected to one end of the solenoid valve coil 3.

[0055] For the working process of the second switch module 2, for example, the third switch module 4 is kept turned on. When the first connection end of the first switch module 1 is turned on with the second connection end of the first switch module 1, after the control end of the second switch module 2 receives the high voltage signal of the starting power supply VDD, the first connection end of the second switch module 2 and the second connection end of the second switch module 2 are cut off, so the maintenance power supply VCC cannot supply power to the coil 3; when the first connection end of the first switch module 1 and the second connection end of the first switch module 1 are cut off, the control end of the second switch module 2 does not receive the high voltage signal of the starting power supply VDD, then the first connection end of the second switch module 2 and the second connection end of the second switch module 2 are turned on, the maintenance power supply VCC can supply power to the coil 3, the coil 3 generates magnetic force, and the solenoid valve works normally.

[0056] Therefore, the working idea of ​​the control circuit is: keep the third switch module 4 turned on, when the first switch module 1 is turned on, the second switch module 2 is turned off, the power supply VDD is started to supply power, and the power supply VCC is maintained to be powered off; when the first switch module 1 is turned off, the second switch module 2 is turned on, the power supply VDD is started to supply power, and the power supply VCC is maintained to be powered on. To ensure the effective driving of the solenoid valve, the duration of the first control signal IO1 must be greater than 200ms.

[0057] With such a configuration, the embodiment of the utility model adopts two power supplies, namely, the startup power supply VDD is used when locking, and the startup power supply VDD can supply power to the coil 3 according to the rated voltage of the solenoid valve. When maintaining the locked state, the maintenance power supply VCC with a lower voltage is used. As long as the solenoid valve can be kept locked, no large voltage is required, thereby reducing the power consumption of the solenoid valve when maintaining the locked state, reducing the temperature rise of the coil 3, and ensuring the service life of the solenoid valve. In addition, since the control end of the second switch module 2 is connected to the second connection end of the first switch module 1, the conduction state of the second switch module 2 is closely related to the first switch module 1, that is, the entire control circuit only needs one control signal to act, and does not need multiple control signals, thereby avoiding the situation where it cannot work when multiple control signals fail. At the same time, when the solenoid valve is not in use, the startup power supply VDD and the maintenance power supply VCC can be directly turned off, so that the solenoid valve can be completely turned off. On this basis, a certain amount of electric energy resources can be saved.

[0058] Further, in an optional implementation, the first switch module 1 includes a first switch tube 11 and a second switch tube 12 .

[0059] Specifically, in the embodiment of the utility model, the control end of the first switch tube 11 is suitable for receiving the first control signal IO1, the first connection end of the first switch tube 11 is grounded, and the second connection end of the first switch tube 11 is connected in series with the first resistor 13, the second resistor 14 and the startup power supply VDD in sequence. The control end of the second switch tube 12 is connected between the first resistor 13 and the second resistor 14, the first connection end of the second switch is connected to the startup power supply VDD, and the second connection end of the second switch is connected to the first end of the coil 3.

[0060] The specific working process is as follows:

[0061] After the control end of the first switch tube 11 receives the first control signal IO1, the first connection end of the first switch tube 11 and the second connection end of the first switch tube 11 are turned on, and the startup power supply VDD, the first resistor 13, the second resistor 14 and the ground form a power supply loop. The input voltage of the control end of the second switch tube 12 is the voltage of the first resistor 13, which is a partial voltage of the startup power supply VDD, so that the first connection end of the second switch tube 12 and the second connection end of the second switch tube 12 are turned on, and the startup power supply VDD supplies power to the coil 3. When the control end of the first switch tube 11 does not receive the first control signal IO1, the first connection end of the first switch tube 11 and the second connection end of the first switch tube 11 are turned off, and the startup power supply VDD, the first resistor 13, the second resistor 14 and the ground cannot form a power supply loop. The input voltage of the control end of the second switch tube 12 is the voltage of the startup power supply VDD, which is high, so that the first connection end of the second switch tube 12 and the second connection end of the second switch tube 12 are turned off, and the startup power supply VDD cannot supply power to the coil 3.

[0062] Further, in an optional implementation, the first switch tube 11 is an N-type transistor, and the second switch tube 12 is a P-type transistor.

[0063] Further, in an optional embodiment, the first switch module 1 also includes a first input resistor 15, one end of the first input resistor 15 is connected to the control end of the first switch tube 11, and the other end of the first input resistor 15 is suitable for receiving the first control signal IO1.

[0064] Further, in an optional implementation, the second switch module 2 includes a third switch tube 21 and a fifth resistor 23 .

[0065] Specifically, in the embodiment of the utility model, the control end of the third switch tube 21 is connected to the second connection end of the first switch module 1 through the fourth resistor 22, one end of the fifth resistor 23 is connected to the control end of the third switch, and the other end of the fifth resistor 23 is grounded.

[0066] The specific working process is as follows:

[0067] When the first switch module 1 is turned on, the startup power supply VDD, the fourth resistor 22, the fifth resistor 23, and the ground form a power supply loop. At this time, the input voltage of the control end of the third switch tube 21 is the voltage of the fifth resistor 23, which is a part of the startup power supply VDD. The voltage is relatively high, so that the first connection end of the third switch tube 21 and the second connection end of the third switch tube 21 are cut off, and the maintenance power supply VCC cannot supply power to the coil 3. When the first switch module 1 is turned off, the startup power supply VDD, the fourth resistor 22, the fifth resistor 23, and the ground cannot form a power supply loop. At this time, the input voltage of the control end of the third switch tube 21 is the voltage of the ground, and the voltage is relatively low, so that the first connection end of the third switch tube 21 and the second connection end of the third switch tube 21 are turned on, and the maintenance power supply VCC can supply power to the coil 3.

[0068] Further, in an optional implementation, the third switch tube 21 is a P-type transistor.

[0069] Furthermore, in an optional implementation, the control circuit further includes a freewheeling diode 5 , a cathode of the freewheeling diode 5 is connected to the first end of the coil 3 , and an anode of the freewheeling diode 5 is connected to the second end of the coil 3 .

[0070] In this way, the embodiment of the utility model can provide a low-impedance freewheeling path for the coil 3 by setting the freewheeling diode 5 when the solenoid valve is powered off, so that the magnetic field energy can be released smoothly. In this process, the freewheeling diode 5 can suppress the reverse electromotive force, and the forward conduction characteristic of the freewheeling diode 5 allows it to be quickly opened when the induced electromotive force is greater than its forward conduction voltage, forming a freewheeling channel. In this way, the reverse electromotive force is clamped within the forward voltage drop range of the diode, effectively preventing the generation of high voltage spikes. In addition, through the freewheeling diode 5, the energy stored in the inductor is gradually consumed in the forward voltage drop of the freewheeling diode 5 and the resistance of the coil 3 itself with a small current, avoiding arc discharge and severe mechanical vibration. At the same time, the smooth current change can obviously reduce the generation of electromagnetic interference, which helps to improve the electromagnetic compatibility of the entire system. Furthermore, since the diode bears most of the reverse electromotive force, other components in the control circuit are no longer subjected to high voltage shocks, thereby being protected and extending their service life.

[0071] Further, in an optional embodiment, the control circuit further includes a third switch module 4, the control end of the third switch module 4 is suitable for receiving the second control signal IO2, the first connection end of the third switch module 4 is connected to the second end of the coil 3, and the second connection end of the third switch module 4 is grounded. Similar to the first switch module 1, the third switch module 4 controls its own conduction and cutoff through the second control signal IO2. The second control signal IO2 and the first control signal IO1 can be high and low level signals.

[0072] With such a configuration, the embodiment of the utility model can directly switch the third switch module 4 from the on state to the off state when the solenoid valve is not needed by configuring the third switch module 4. This is simple and convenient, and there is no need to operate the startup power supply VDD and the maintenance power supply VCC, thus reducing the operation process.

[0073] Further, in an optional implementation, the third switch module 4 includes a second input resistor 41 and a fourth switch tube 42 .

[0074] Specifically, in the embodiment of the utility model, the first end of the second input resistor 41 receives the second control signal IO2, the control end of the fourth switch tube 42 is connected to the second end of the second input resistor 41, the first connection end of the fourth switch tube 42 is connected to the second end of the coil 3, and the second connection end of the fourth switch tube 42 is grounded. The fourth switch tube 42 can be an N-type triode.

[0075] In the embodiment of the utility model, all switch tubes can be corresponding MOS tubes.

[0076] In a second aspect, the utility model further provides a microwave oven, the microwave oven comprising:

[0077] A box body, wherein a cooking cavity is provided;

[0078] A door body is rotatably arranged on the box body; a door lock is arranged on the door body, and the door lock is suitable for being locked in the lock hole of the box body;

[0079] The lock core of the door lock is locked and unlocked by a solenoid valve, and the solenoid valve uses a control circuit of the solenoid valve as described in any of the above embodiments.

[0080] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A control circuit for a solenoid valve, characterized in that: include: The starting power supply (VDD) is used to provide an initial driving voltage to switch the solenoid valve to a locked state; A maintenance power supply (VCC), used for providing a maintenance driving voltage to keep the solenoid valve in the locked state; the voltage of the maintenance power supply (VCC) is lower than the voltage of the start power supply (VDD); A first switch module (1), wherein a control end of the first switch module (1) is adapted to receive a first control signal (IO1), a first connection end of the first switch module (1) is connected to the start-up power supply (VDD), a second connection end of the first switch module (1) is connected to a first end of a coil (3) of the solenoid valve, and a second end of the coil (3) is grounded via a third switch module (4); a second switch module (2), wherein a control end of the second switch module (2) is connected to a second connection end of the first switch module (1), a first connection end of the second switch module (2) is connected to the maintenance power supply (VCC), and a second connection end of the second switch module (2) is connected to one end of the coil (3); When the third switch module (4) is turned on, the first switch module (1) is turned on, the second switch module (2) is turned off, and the starting power supply (VDD) supplies power to the coil (3); or, when the third switch module (4) is turned on, the first switch module (1) is turned off, the second switch module (2) is turned on, and the maintaining power supply (VCC) supplies power to the coil (3).

2. The control circuit according to claim 1, characterized in that: The first switch module (1) comprises: a first switch tube (11), wherein a control end of the first switch tube (11) is adapted to receive the first control signal (IO1), a first connection end of the first switch tube (11) is grounded, and a second connection end of the first switch tube (11) is sequentially connected in series with a first resistor (13), a second resistor (14) and the startup power supply (VDD); A second switch tube (12), wherein a control end of the second switch tube (12) is connected between the first resistor (13) and the second resistor (14), a first connection end of the second switch is connected to the startup power supply (VDD), and a second connection end of the second switch is connected to the first end of the coil (3).

3. The control circuit according to claim 2, characterized in that: The first switch tube (11) is an N-type triode, and the second switch tube (12) is a P-type triode.

4. The control circuit according to claim 3, characterized in that: The first switch module (1) further comprises: A first input resistor (15), one end of which is connected to the control end of the first switch tube (11), and the other end of which is suitable for receiving the first control signal (IO1).

5. The control circuit according to any one of claims 1 to 4, characterized in that: The second switch module (2) comprises: A third switch tube (21), wherein a control end of the third switch tube (21) is connected to a second connection end of the first switch module (1) via a fourth resistor (22); A fifth resistor (23), one end of the fifth resistor (23) is connected to the control end of the third switch, and the other end of the fifth resistor (23) is grounded.

6. The control circuit according to claim 5, characterized in that: The third switch tube (21) is a P-type triode.

7. The control circuit according to any one of claims 1 to 4, characterized in that: The control circuit also includes: A freewheeling diode (5), wherein a cathode of the freewheeling diode (5) is connected to a first end of the coil (3), and an anode of the freewheeling diode (5) is connected to a second end of the coil (3).

8. The control circuit according to any one of claims 1 to 4, characterized in that: The control end of the third switch module (4) is suitable for receiving a second control signal (IO2), the first connection end of the third switch module (4) is connected to the second end of the coil (3), and the second connection end of the third switch module (4) is grounded.

9. The control circuit according to claim 8, characterized in that: The third switch module (4) comprises: A second input resistor (41), a first end of the second input resistor (41) receiving the second control signal (IO2); A fourth switch tube (42), wherein a control end of the fourth switch tube (42) is connected to the second end of the second input resistor (41), a first connection end of the fourth switch tube (42) is connected to the second end of the coil (3), and a second connection end of the fourth switch tube (42) is grounded.

10. A microwave oven, characterized in that: include: A box body, wherein a cooking cavity is provided; A door body is rotatably arranged on the box body; a door lock is arranged on the door body, and the door lock is suitable for being locked in the lock hole of the box body; The lock core of the door lock is locked and unlocked by a solenoid valve, and the solenoid valve uses a control circuit of the solenoid valve as described in any one of claims 1 to 9.

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