A relay control circuit and a household appliance

Abstract

The present invention relates to a relay control circuit and a household electrical appliance. The circuit includes a first switch circuit, a second switch circuit, a first energy storage circuit, a second energy storage circuit, and a controller. When the controller outputs a first level signal with a duration equal to the charging duration of the first energy storage circuit, both the first energy storage circuit and the second energy storage circuit perform energy storage, controlling both the first switch circuit and the second switch circuit to conduct, so that the coil of the relay is powered on to work. When the controller outputs a second level signal with a duration equal to the discharging duration of the second energy storage circuit, the first energy storage circuit discharges, controlling the first switch circuit to cut off, the second energy storage circuit discharges, and the second switch circuit conducts, so that the coil of the relay maintains power on. Therefore, when an abnormal situation occurs in the controller and it is unable to control the first energy storage circuit and the second energy storage circuit to alternately perform energy storage and discharge, the relay will be powered off and disconnected, improving the safety and reliability of relay control.

Description

Technical Field

[0001] The present invention relates to the field of relay control, and particularly to a relay control circuit and a household electrical appliance device. Background Art

[0002] In current household electrical appliances, most load controls use relay control. And the current control method of the relay is to output a corresponding drive signal through a controller to drive the relay to be powered on and turned on.

[0003] During the operation of the product, controller failures may occur, such as electrostatic breakdown and program runaway. Such failure conditions will cause the controller to short-circuit, and then cause the relay to be always turned on and unable to be turned off, and the load to be always in an uncontrolled on state, increasing the safety hazard of the load catching fire and burning, and unable to ensure personal safety. Summary of the Invention

[0004] Embodiments of the present invention aim to provide a relay control circuit and a household electrical appliance device, which can prevent the relay from being out of control under abnormal conditions and improve safety and reliability.

[0005] To solve the above technical problems, the embodiments of the present invention provide the following technical solutions:

[0006] In a first aspect, an embodiment of the present invention provides a relay control circuit, which includes: a first switch circuit, a second switch circuit, a first energy storage circuit, a second energy storage circuit, and a controller;

[0007] A first end of the first energy storage circuit is connected to the controller, a second end of the first energy storage circuit is respectively connected to a first DC power supply and a first end of the first switch circuit, and a third end of the first energy storage circuit is connected to a control end of the first switch circuit;

[0008] A second end of the first switch circuit is respectively connected to a control end of the second switch circuit and a first end of the second energy storage circuit. The first switch circuit is used to control the connection state between the first DC power supply and the control end of the second switch circuit, and to control the connection state between the first DC power supply and the first end of the second energy storage circuit;

[0009] A first end of the second switch circuit is connected to one end of a coil of the relay, a second end of the second switch circuit is grounded, and the other end of the coil of the relay is connected to a second DC power supply. The second switch circuit is used to control the connection state between the coil of the relay and the ground;

[0010] When the controller outputs a first level signal, the first energy storage circuit performs an energy storage operation to control the first switching circuit to be in a conducting state, so that the second switching circuit is in a conducting state, where the duration of the first level signal is less than or equal to the charging duration of the first energy storage circuit, and the charging duration of the first energy storage circuit is the duration required for the first energy storage circuit to be fully charged; the first energy storage circuit is further configured to perform a discharging operation to control the first switching circuit to be in a cut-off state when the controller outputs a second level signal;

[0011] The second end of the second energy storage circuit is grounded. The second energy storage circuit is configured to perform an energy storage operation when the first switching circuit is in a conducting state, and is further configured to perform a discharging operation when the first switching circuit is in a cut-off state, so that the second switching circuit is in a conducting state, where the duration of the second level signal is less than or equal to the discharging duration of the second energy storage circuit, and the discharging duration of the second energy storage circuit is the duration required for the second energy storage circuit to release all the electrical energy after being fully charged.

[0012] In some embodiments, the first energy storage circuit includes a capacitive module and a discharging module;

[0013] One end of the capacitive module is respectively connected to the control end of the first switching circuit and the first end of the discharging module, and the other end of the capacitive module is respectively connected to the second end of the discharging module and the controller. The capacitive module is configured to perform an energy storage operation when the controller outputs a first level signal, and the capacitive module is further configured to perform a discharging operation when the controller outputs a second level signal;

[0014] The third end of the discharging module is respectively connected to the first DC power supply and the first end of the first switching circuit. The discharging module is configured to receive the electrical energy released by the capacitive module when the capacitive module performs a discharging operation.

[0015] In some embodiments, the capacitive module includes a first capacitor, and the discharging module includes a first diode and a first resistor;

[0016] One end of the first capacitor is respectively connected to the control end of the first switching circuit and the anode of the first diode, and the other end of the first capacitor is respectively connected to the controller and one end of the first resistor. The cathode of the first diode is respectively connected to the first DC power supply and the other end of the first resistor.

[0017] In some embodiments, the first switching circuit includes a first triode, a second resistor, and a third resistor;

[0018] The base of the first triode is respectively connected to one end of the second resistor and one end of the third resistor. The emitter of the first triode is respectively connected to the first DC power supply, the other end of the third resistor, and the second end of the first energy storage circuit. The collector of the first triode is respectively connected to the first end of the second energy storage circuit and the control end of the second switch circuit. The other end of the second resistor is connected to the third end of the first energy storage circuit.

[0019] In some embodiments, the second switch circuit includes a fourth resistor, a fifth resistor, and a second triode;

[0020] One end of the fourth resistor is connected to the second end of the first switch circuit. The other end of the fourth resistor is respectively connected to one end of the fifth resistor and the base of the second triode;

[0021] The other end of the fifth resistor and the emitter of the second triode are commonly grounded. The collector of the second triode is connected to the coil of the relay.

[0022] In some embodiments, the second energy storage circuit includes a sixth resistor and a second capacitor;

[0023] One end of the sixth resistor is respectively connected to the second end of the first switch circuit and the control end of the second switch circuit. The other end of the sixth resistor is connected to one end of the second capacitor. The other end of the second capacitor is grounded.

[0024] In some embodiments, the first level signal and the second level signal together constitute a PWM wave signal. When the controller fails, the fault signal output by the controller is different from the PWM wave signal.

[0025] In a second aspect, an embodiment of the present invention provides a household electrical appliance, which includes: a relay and the relay control circuit as described above;

[0026] The relay control circuit is used to control the working state of the relay.

[0027] In various embodiments of the present invention, the relay control circuit includes a first switch circuit, a second switch circuit, a first energy storage circuit, a second energy storage circuit, and a controller. Among them, when the controller outputs a first level signal, the first energy storage circuit performs an energy storage operation to control the first switch circuit to be in a conducting state. The first switch circuit further controls the second switch circuit to be in a conducting state, so that the coil of the relay is powered on to work. At the same time, the second energy storage circuit performs an energy storage operation. When the controller outputs a second level signal, the first energy storage circuit performs a discharging operation. At this time, the first switch circuit is in a cut-off state. At the same time, the second energy storage circuit performs a discharging operation, so that the coil of the relay continues to maintain the powered-on working state. Among them, the duration of the first level signal is the charging duration of the first energy storage circuit, and the duration of the second level signal is the discharging duration of the second energy storage circuit, so that the relay can always maintain the powered-on working state and the load can be normally powered on to work. Therefore, only when the controller alternately outputs the first level signal and the second level signal with a specific duration, so that the first energy storage circuit and the second energy storage circuit alternately perform energy storage operations and discharging operations, can the working state of the relay be controlled. When an abnormal situation occurs in the controller, it will always output the first level signal or the second level signal, and then it is impossible to control the first energy storage circuit and the second energy storage circuit to alternately perform energy storage operations and discharging operations, and further the relay is in a power-off and disconnected state to prevent the relay from being always powered on and uncontrolled in an abnormal situation, thereby improving the safety and reliability of relay control. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplary illustrations do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the drawings in the figures do not constitute a proportional limitation.

[0029] Figure 1 It is a schematic structural diagram of one of the household electrical appliances provided by the embodiment of the present invention;

[0030] Figure 2 It is a schematic structural diagram of one of the relay control circuits provided by the embodiment of the present invention;

[0031] Figure 3 It is a schematic circuit diagram of one of the relay control circuits provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0033] Household electrical appliances can be devices that protect relay devices arbitrarily, such as washing machines, refrigerators, and air conditioners.

[0034] Please refer to Figure 1 , the embodiment of the present invention provides a schematic structural diagram of a household electrical appliance. The household electrical appliance 100 includes a relay control circuit 10 and a relay 20. Among them, the relay 20 includes a coil and a contact. The relay control circuit 10 is used to control the energization of the coil of the relay 20 to control the action of the contact, and further control the working state of the relay 20.

[0035] The relay 20 is mostly used to control a load, and the working state of the relay 20 is controlled to control the load.

[0036] Most current relay control methods use a controller to drive a triode to turn on the relay. The controller needs to continuously output a drive level signal to keep the relay in the on state. When the controller outputs another level signal, the relay is turned off.

[0037] If the controller fails, such as an internal open circuit or short circuit, program runaway, or external electrostatic breakdown, etc., the controller may continuously output a drive level signal, which will cause the relay to be in the on state all the time, making the relay uncontrollable, reducing the safety and reliability of the relay, and the load is also in an uncontrolled state all the time, increasing the safety hazard of the load and unable to ensure personal safety.

[0038] Therefore, it is necessary to prevent the situation where the relay is out of control when the controller fails, and improve the safety and reliability of the relay.

[0039] The embodiment of the present invention separates the drive signal of the relay from the signal output when the controller fails to prevent the relay from being uncontrollable when the controller fails.

[0040] Please refer to Figure 2 , Figure 2 is a schematic structural diagram of a relay control circuit provided by the embodiment of the present invention. As Figure 2 shown, the relay control circuit 10 includes a switch circuit 11, a first energy storage circuit 12, a second energy storage circuit 14, and a controller 13. Among them, the switch circuit 11 includes a first switch circuit 111 and a second switch circuit 112.

[0041] The first end of the first energy storage circuit 12 is connected to the controller 13, the second end of the first energy storage circuit 12 is respectively connected to a first DC power supply 200 and the first end of the first switch circuit 111, and the third end of the first energy storage circuit 12 is connected to the control end of the first switch circuit 111.

[0042] The second end of the first switching circuit 111 is respectively connected to the control end of the second switching circuit 112 and the first end of the second energy storage circuit 14, and the second end of the second energy storage circuit 14 is grounded.

[0043] The first end of the second switching circuit 112 is connected to one end of the coil of the relay 20, the second end of the second switching circuit 112 is grounded, and the other end of the coil of the relay 20 is connected to the second DC power supply.

[0044] The first switching circuit 111 is used to control the connection state between the first DC power supply 200 and the control end of the second switching circuit 112, and is used to control the connection state between the first DC power supply and the first end of the second energy storage circuit 14. The second switching circuit 112 is used to control the connection state between the coil of the relay 20 and the ground.

[0045] In some embodiments, the first switching circuit 111 and the second switching circuit 112 can be any module capable of realizing the switching function, such as a triode module, a MOS tube module, an IGBT module, an electronic switch, etc.

[0046] When the controller 13 outputs a first level signal, the first energy storage circuit 12 performs an energy storage operation, so that the first switching circuit 111 is in a conducting state, to control the connection between the first DC power supply 200 and the control end of the second switching circuit 112, so that the second switching circuit 112 is in a conducting state, and further to control the connection between the coil of the relay 20 and the ground. The second DC power supply 300, the coil of the relay 20 and the ground form a loop, the coil of the relay 20 is energized, and the relay 20 is turned on.

[0047] At the same time, when the first energy storage circuit 12 performs an energy storage operation, the first switching circuit 111 is in a conducting state, and further the second switching circuit 112 is in a conducting state to control the relay 20 to turn on. At the same time, when the first switching circuit 111 is turned on, the second energy storage circuit 14 performs an energy storage operation, and the first DC power supply 200 charges the second energy storage circuit 14.

[0048] Wherein, the duration of the first level signal is less than or equal to the charging duration of the first energy storage circuit 12, and the charging duration of the first energy storage circuit 12 is the duration required for the first energy storage circuit 12 to be fully charged.

[0049] When the controller 13 outputs a second level signal, the first energy storage circuit 12 performs a discharging operation, so that the first switching circuit 111 is in a cut-off state, to control the disconnection between the first DC power supply 200 and the control end of the second switching circuit 112.

[0050] Meanwhile, the second energy storage circuit 14 performs a discharging operation, and the discharged electric quantity acts on the control end of the second switch circuit 112, so that the second switch circuit 112 remains in the conducting state.

[0051] Wherein, the duration of the second level signal is equal to the discharging duration of the second energy storage circuit 14, and the discharging duration of the second energy storage circuit 14 is the duration required for the second energy storage circuit 14 to release all the electric energy after being fully charged.

[0052] Therefore, when the controller 13 outputs the second level signal, the second energy storage circuit 14 can maintain the second switch circuit 112 in the conducting state, and further maintain the relay 20 in the conducting state.

[0053] In some embodiments, the specific forms of the first level signal and the second level signal can be determined according to the switch module, and are not limited herein.

[0054] In some embodiments, the controller 13 can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a single-chip microcomputer, an ARM (Acorn RISC Machine), or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of these components. Moreover, the controller 13 can also be any conventional processor, controller, microcontroller, or state machine. The controller 13 can also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP and / or any other such configuration. The controller 13 can also be the variable-frequency board or the main control board of the washing machine.

[0055] In the embodiment of the present invention, when the controller 13 outputs the second level signal, the second energy storage circuit 14 performs a discharging operation to make the second switch circuit 112 continue to conduct, so that the relay 20 remains in the conducting state. When the discharging of the second energy storage circuit 14 ends, the controller 13 outputs the first level signal to make the first energy storage circuit 12 continue to charge, the first switch circuit 111 conducts, and the second switch circuit 112 continues to conduct, so that the relay 20 continues to be in the conducting state.

[0056] Therefore, in a scenario where the load needs to be always powered on and the relay 20 is always in the conducting state, the relay control circuit 10 can keep the relay 20 in the conducting state all the time to meet the requirement of keeping the load powered on, without alternating conduction and cut-off.

[0057] In an embodiment of the present invention, the relay 20 can be kept in a conducting state by adjusting the duration of the first level signal and the duration of the second level signal. The first level signal and the second level signal can be in the form of PWM wave signals, and the relay 20 is kept in a conducting state by adjusting the duty cycle of the PWM wave signals.

[0058] During the first level signal, the first energy storage circuit 12 performs an energy storage operation, the second energy storage circuit 14 performs an energy storage operation, and the coil of the relay 20 is powered on. During the second level signal, the first energy storage circuit 12 performs a discharging operation, and the second energy storage circuit 14 performs a discharging operation to maintain the coil of the relay 20 in a powered-on state. When the discharging of the second energy storage circuit 14 ends, the charging cycle of the next period starts.

[0059] When the controller 13 malfunctions, it will continuously output the first level signal or the second level signal, so that the first energy storage circuit 12 and the second energy storage circuit 14 cannot perform energy storage and discharging alternately normally, and the relay 20 cannot maintain a continuously conducting state, so as to prevent the relay 20 from being continuously powered on uncontrollably.

[0060] Moreover, the first switch circuit 111 and the second switch circuit 112 cooperate with each other to control the state of the relay 20, which can further improve the safety and reliability.

[0061] In summary, only when the controller 13 alternately outputs the first level signal and the second level signal with specific durations, can the first energy storage circuit 12 and the second energy storage circuit 14 perform energy storage operations and discharging operations alternately, thereby controlling the working state of the relay 20 and enabling the load to work normally. When the controller 13 malfunctions, it will continuously output the first level signal or the second level signal, so that the first energy storage circuit 12 and the second energy storage circuit 14 cannot perform energy storage operations and discharging operations alternately, thereby causing the relay 20 to be in an off state to prevent the relay 20 from being continuously powered on uncontrollably under abnormal conditions and improving the safety and reliability of the control of the relay 20.

[0062] In some embodiments, the first energy storage circuit 12 includes a capacitive module 121 and a discharging module 122.

[0063] One end of the capacitive module 121 is respectively connected to the control end of the first switch circuit 111 and the first end of the discharging module 122, and the other end of the capacitive module 121 is respectively connected to the second end of the discharging module 122 and the controller 13. The third end of the discharging module 122 is respectively connected to the first DC power supply 200 and the first end of the first switch circuit 111.

[0064] When the controller 13 outputs a first level signal, the capacitive module 121 performs an energy storage operation. When the controller 13 outputs a second level signal, the capacitive module 121 performs a discharging operation. When the capacitive module 121 performs the discharging operation, the discharging module 122 receives the electric energy released by the capacitive module 121.

[0065] Please refer to Figure 3 , Figure 3 which is a schematic structural diagram of a relay control circuit provided by an embodiment of the present invention. As Figure 3 shown, the capacitive module 121 includes a first capacitor C1, and the discharging module 122 includes a first diode D1 and a first resistor R1.

[0066] One end of the first capacitor C1 is respectively connected to the control end of the first switch circuit 111 and the anode of the first diode D1. The other end of the first capacitor C1 is respectively connected to the controller 13 and one end of the first resistor R1. The cathode of the first diode D1 is respectively connected to the first DC power supply 200 and the other end of the first resistor R1.

[0067] The first switch circuit 111 includes a first triode Q1, a second resistor R2, and a third resistor R3.

[0068] The base of the first triode Q1 is respectively connected to one end of the second resistor R2 and one end of the third resistor R3. The emitter of the first triode Q1 is respectively connected to the first DC power supply 200, the other end of the third resistor R3, and the second end of the first energy storage circuit 12. The collector of the first triode Q1 is respectively connected to the first end of the second energy storage circuit 14 and the control end of the second switch circuit 112. The other end of the second resistor R2 is connected to the third end of the first energy storage circuit 12.

[0069] Specifically, the emitter of the first triode Q1 is respectively connected to the first DC power supply 200, the other end of the third resistor R3, the cathode of the first diode D1, and the first resistor R1. The other end of the second resistor R2 is respectively connected to the anode of the first diode D1 and the first capacitor C1.

[0070] The second switch circuit 112 includes a fourth resistor R4, a fifth resistor R5, and a second triode Q2.

[0071] One end of the fourth resistor R4 is connected to the second end of the first switch circuit 111. Specifically, one end of the fourth resistor R4 is connected to the collector of the first triode Q1. The other end of the fourth resistor R4 is respectively connected to one end of the fifth resistor R5 and the base of the second triode Q2. The other end of the fifth resistor R5 and the emitter of the second triode Q2 are commonly grounded, and the collector of the second triode Q2 is connected to the coil RY1 of the relay 20.

[0072] In the embodiment of the present invention, the first triode Q1 is a PNP triode with the model MMBT3906, and the second triode Q2 is an NPN triode with the model MMBT3904. The voltage of the first DC power supply 200 is +5V, and the voltage of the second DC power supply is +12V.

[0073] The second energy storage circuit 14 includes a sixth resistor R6 and a second capacitor C2. One end of the sixth resistor R6 is respectively connected to the second end of the first switch circuit 111 and the control end of the second switch circuit 112. Specifically, one end of the sixth resistor R6 is respectively connected to the collector of the first triode Q1 and the fourth resistor R4. The other end of the sixth resistor R6 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is grounded.

[0074] The relay control circuit 10 may further include a current limiting resistor R7. One end of the current limiting resistor R7 is connected to the controller 13 through the RELAY connection. The other end of the current limiting resistor R7 is respectively connected to the first resistor R1 and the first capacitor C1. The controller 13 outputs a first level signal or a second level signal through the RELAY connection.

[0075] Combined Figure 3 , the working principle of the relay control circuit 10 can be described as follows:

[0076] When the controller 13 outputs a first level signal, using the AC-pass and DC-block characteristics of the first capacitor C1, the first DC power supply 200, the emitter and base of the first triode Q1, the second resistor R2, the first capacitor C1, and the current limiting resistor R7 form a closed loop, and the first triode Q1 conducts. At the same time, the first DC power supply 200 charges the first capacitor C1.

[0077] The conduction of the first triode Q1 causes the first DC power supply 200 to act on the base of the second triode Q2 through the first triode Q1, making the second triode Q2 conduct. The second DC power supply 300 powers on the coil RY1 of the relay 20, and the relay 20 is in the conduction state. At the same time, the first DC power supply 200 also charges the second capacitor C2 through the first triode Q1, enabling the second capacitor C2 to store electrical energy.

[0078] When the controller 13 outputs a second-level signal, the first capacitor C1 discharges, and the electrical energy stored in the first capacitor C1 is released to the first diode D1 and the first resistor R1. At the same time, the first capacitor C1 releases electrical energy, and the first capacitor C1 is equivalent to an open circuit, and the first triode Q1 is cut off;

[0079] When the first triode Q1 is cut off, the second capacitor C2 discharges, releasing the stored electrical energy to the base of the second triode Q2, maintaining the second triode Q2 in the conducting state, and further maintaining the coil RY1 of the relay 20 still energized, and the relay 20 is still in the conducting state.

[0080] In the embodiment of the present invention, the first-level signal and the second-level signal together constitute a PWM wave, the first-level signal is a low-level signal, and the second-level signal is a high-level signal.

[0081] The duration of the first-level signal can be set as the charging duration of the first capacitor C1, and the duration of the second-level signal can be set as the discharging duration of the second capacitor C2. Then, the larger the first capacitor C1, the longer its charging duration, and the longer the duration of the first-level signal. The larger the second capacitor C2, the more electrical energy it stores, the longer its discharging duration, and the longer the duration of the second-level signal, that is, the longer the period of the PWM wave. Therefore, by setting the parameters of the first capacitor C1 and the second capacitor C2, the period and duty cycle of the PWM wave output by the controller 13 can be adjusted.

[0082] If the period and duty cycle of the PWM wave are set according to the charging duration of the first capacitor C1 and the discharging duration of the second capacitor C2 in the above manner, then during the energy release period of the first capacitor C1, the second capacitor C2 also releases electrical energy to maintain the relay 20 in the conducting state. When the energy of the second capacitor C2 is released, the next cycle of charging is carried out. By adjusting the first capacitor C1 and the second capacitor C2, the frequency and duty cycle of the PWM output by the controller 13 can be fixed, and the uniqueness of the drive signal can also be fixed. Only when the controller 13 outputs this frequency and duty cycle signal can the relay 20 be turned on. In the embodiment of the present invention, the frequency of the PWM wave is 600HZ, and the duty cycle is 90% on.

[0083] In summary, only when the controller alternately outputs the first-level signal and the second-level signal with specific durations, can the first energy storage circuit alternately perform energy storage operations and discharge operations, thereby controlling the working state of the relay and enabling the load to work normally. When an abnormal situation occurs in the controller, it will always output the first-level signal or the second-level signal, then it is impossible to control the first energy storage circuit to alternately perform energy storage operations and discharge operations, thereby causing the relay to be in the off state to prevent the relay from being continuously powered on and out of control in an abnormal situation, and improving the safety and reliability of relay control.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; under the idea of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above. For the sake of brevity, they are not provided in detail; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A relay control circuit, characterized in that, The relay control circuit includes: a first switch circuit, a second switch circuit, a first energy storage circuit, a second energy storage circuit, and a controller; A first end of the first energy storage circuit is connected to the controller, a second end of the first energy storage circuit is respectively connected to a first DC power supply and a first end of the first switch circuit, and a third end of the first energy storage circuit is connected to a control end of the first switch circuit; A second end of the first switch circuit is respectively connected to a control end of the second switch circuit and a first end of the second energy storage circuit. The first switch circuit is used to control the connection state between the first DC power supply and the control end of the second switch circuit, and is used to control the connection state between the first DC power supply and the first end of the second energy storage circuit; A first end of the second switch circuit is connected to one end of a coil of the relay, a second end of the second switch circuit is grounded, and the other end of the coil of the relay is connected to a second DC power supply. The second switch circuit is used to control the connection state between the coil of the relay and the ground; When the controller outputs a first level signal, the first energy storage circuit performs an energy storage operation to control the first switch circuit to be in a conducting state, so that the second switch circuit is in a conducting state. Wherein, the duration of the first level signal is less than or equal to the charging duration of the first energy storage circuit, and the charging duration of the first energy storage circuit is the duration required for the first energy storage circuit to be fully charged; The first energy storage circuit is further used to perform a discharging operation to control the first switch circuit to be in a cut-off state when the controller outputs a second level signal; A second end of the second energy storage circuit is grounded. The second energy storage circuit is used to perform an energy storage operation when the first switch circuit is in a conducting state, and is further used to perform a discharging operation when the first switch circuit is in a cut-off state, so that the second switch circuit is in a conducting state. Wherein, the duration of the second level signal is less than or equal to the discharging duration of the second energy storage circuit, and the discharging duration of the second energy storage circuit is the duration required for the second energy storage circuit to release all electric energy after being fully charged; The first energy storage circuit includes a capacitive module and a discharging module; One end of the capacitive module is respectively connected to the control end of the first switch circuit and a first end of the discharging module, and the other end of the capacitive module is respectively connected to a second end of the discharging module and the controller. The capacitive module is used to perform an energy storage operation when the controller outputs a first level signal, and the capacitive module is further used to perform a discharging operation when the controller outputs a second level signal; A third end of the discharging module is respectively connected to the first DC power supply and the first end of the first switch circuit. The discharging module is used to receive the electric energy released by the capacitive module when the capacitive module performs a discharging operation.

2. The relay control circuit according to claim 1, characterized in that, The capacitive module includes a first capacitor, and the discharging module includes a first diode and a first resistor; One end of the first capacitor is respectively connected to the control end of the first switching circuit and the anode of the first diode. The other end of the first capacitor is respectively connected to the controller and one end of the first resistor. The cathode of the first diode is respectively connected to the first DC power supply and the other end of the first resistor.

3. The relay control circuit according to claim 1, characterized in that, The first switching circuit includes a first triode, a second resistor, and a third resistor. The base of the first triode is respectively connected to one end of the second resistor and one end of the third resistor. The emitter of the first triode is respectively connected to the first DC power supply, the other end of the third resistor, and the second end of the first energy storage circuit. The collector of the first triode is respectively connected to the first end of the second energy storage circuit and the control end of the second switching circuit. The other end of the second resistor is connected to the third end of the first energy storage circuit.

4. The relay control circuit according to claim 3, characterized in that, The second switching circuit includes a fourth resistor, a fifth resistor, and a second triode. One end of the fourth resistor is connected to the second end of the first switching circuit. The other end of the fourth resistor is respectively connected to one end of the fifth resistor and the base of the second triode. The other end of the fifth resistor and the emitter of the second triode are commonly grounded. The collector of the second triode is connected to the coil of the relay.

5. The relay control circuit according to claim 1, characterized in that, The second energy storage circuit includes a sixth resistor and a second capacitor. One end of the sixth resistor is respectively connected to the second end of the first switching circuit and the control end of the second switching circuit. The other end of the sixth resistor is connected to one end of the second capacitor. The other end of the second capacitor is grounded.

6. The relay control circuit according to any one of claims 1-5, characterized in that, The first level signal and the second level signal together constitute a PWM wave signal. When the controller fails, the fault signal output by the controller is different from the PWM wave signal.

7. A household electrical appliance, characterized in that, The household electrical appliance includes: a relay and the relay control circuit according to any one of claims 1-6. The relay control circuit is used to control the working state of the relay.

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