Door lock protection device and household appliance

Abstract

The invention discloses a door lock protection device and a household appliance. The device is applied to electrical equipment, and the electrical equipment comprises a door lock, a driving control circuit, a power circuit, a load, a door lock switch detection circuit, a power failure detection circuit and a logic circuit. The power failure detection circuit is respectively connected with the door lock switch detection circuit, the logic circuit and the driving control circuit, the driving control circuit is connected with the power circuit through the logic circuit, and the load is connected with the power circuit; the power failure detection circuit determines that a door lock is unlocked according to a door lock opening and closing state and outputs a power failure signal to the logic circuit; and the logic circuit converts the level signal output by the driving control circuit into a target level signal and outputs the target level signal to the power circuit for driving the power circuit to stop supplying power to the load. Therefore, potential safety hazards caused by the fact that the electrical equipment still operates when the door is suddenly opened in the using process are avoided, and safety and reliability of the electrical equipment are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of door lock protection, and in particular to a door lock protection device and household electrical appliances. Background Art

[0002] As people's quality of life improves, electrical equipment has gradually become an indispensable part of people's lives. While electrical equipment brings convenience to people, it also inevitably has some safety hazards. For example, a dishwasher uses hot water to rinse dishes. If the user suddenly opens the door during the dishwasher washing process, the dishwasher spray arm is still rotating at high speed, and the hot water on the spray arm will spray directly, causing burns to the user. Therefore, electrical equipment door lock protection that can improve the safety of opening the door is a technical problem that the industry urgently needs to solve. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the defect in the prior art that when a user suddenly opens the door during the use of an electrical device, the high-voltage load of the electrical device is still running, which may cause safety hazards, and provide a door lock protection circuit and household appliance.

[0004] The present invention solves the above technical problems through the following technical solutions:

[0005] In a first aspect, a door lock protection device is provided, which is applied to an electrical device, wherein the electrical device includes a door lock, a drive control circuit, a power circuit and a load; the door lock protection device includes a door lock switch detection circuit, a power failure detection circuit and a logic circuit; the power failure detection circuit is respectively connected to the door lock switch detection circuit, the logic circuit and the drive control circuit, the drive control circuit is connected to the power circuit through the logic circuit, and the load is connected to the power circuit;

[0006] The door lock switch detection circuit detects the switch state of the door lock and outputs the switch state signal of the door lock to the power failure detection circuit;

[0007] The power-off detection circuit determines, based on the switch state signal, that the door lock is unlocked when the electrical device is in operation, and outputs a power-off signal to the logic circuit;

[0008] The logic circuit converts the level signal output by the drive control circuit into a target level signal, and outputs the target level signal to the power circuit;

[0009] The target level signal is used to drive the power circuit to stop supplying power to the load.

[0010] Optionally, the drive control circuit includes a drive chip; the power circuit includes an intelligent power module; the logic circuit includes a NOT gate and an AND gate array;

[0011] The input end of the NOT gate is connected to the output end of the power-off detection circuit and the power control end of the driving chip respectively, the output end of the NOT gate is connected to the first input end of each AND gate included in the AND gate array, the second input end of each AND gate is connected to a first power driving pin corresponding to the driving chip, and the output end of each AND gate is connected to a second power driving pin corresponding to the intelligent power module.

[0012] Optionally, the load includes a motor; the AND gate array includes 6 AND gates; the intelligent power module includes 6 second power drive pins and a three-phase power supply output terminal;

[0013] The output end of each AND gate is connected to a corresponding second power drive pin;

[0014] The three-phase power supply output terminal is connected to the input terminal of the motor.

[0015] Optionally, the door lock switch detection circuit includes: an optocoupler device, a switch tube and a voltage conversion subcircuit;

[0016] The input end of the voltage conversion subcircuit is connected to the output end of the switch tube, and the input end of the switch tube is connected to the power supply; the input end and the control end of the switch tube are also connected to the output end of the optocoupler device, and the input end of the optocoupler device is connected to the door lock;

[0017] The optocoupler device is used to detect the switch state of the door lock;

[0018] When the switch state of the door lock is a locked state, the switch tube is turned on; when the switch state of the door lock is an unlocked state, the switch tube is turned off.

[0019] Optionally, the optocoupler device includes an optocoupler diode and an optocoupler triode;

[0020] The cathode of the optocoupler diode is connected to the door lock, and the anode of the optocoupler diode is connected to the first resistor;

[0021] The optocoupler transistor is connected to the switch tube via a second resistor.

[0022] Optionally, the switch tube includes a triode;

[0023] The base of the transistor is connected to the optical coupler device via a second resistor;

[0024] The emitter and base of the triode are short-circuited and connected to the power supply via a third resistor;

[0025] The collector of the triode is connected to the voltage conversion sub-circuit.

[0026] Optionally, the voltage conversion subcircuit includes a first capacitor, a second capacitor, a first voltage stabilizing integrated circuit and a second voltage stabilizing integrated circuit;

[0027] The input end of the second capacitor is connected to the first capacitor, the first voltage stabilizing integrated circuit is connected to the second voltage stabilizing integrated circuit, and the output end of the second capacitor is connected to the power-off detection circuit.

[0028] Optionally, the power-off detection circuit includes a diode and a fourth resistor;

[0029] The input end of the diode is connected to the door lock switch detection circuit, and the output end of the diode is connected to the input end of the logic circuit and the drive control circuit respectively;

[0030] The fourth resistor is connected to the output end of the diode and the door lock switch detection circuit respectively.

[0031] Optionally, the device further includes an active control circuit and a communication circuit;

[0032] The output end of the active control circuit is connected to the drive control circuit via a communication circuit;

[0033] The input end of the active control circuit is connected to the door lock switch detection circuit through a third resistor.

[0034] In a second aspect, a household appliance is provided, wherein the household appliance comprises the door lock protection device of any one of the above items.

[0035] The positive progressive effect of the present invention is that: in the embodiment of the present invention, by detecting the switch state of the door lock of the electrical equipment, when it is determined that the door lock is in the unlocked state, logical control is used to forcibly set the level state of the input power circuit to drive the power circuit to stop supplying power to the load, thereby solving the defect that the user suddenly opens the door during the use of the electrical equipment and the electrical equipment is still running, which will cause a safety hazard, and improves the safety and reliability of the electrical equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic structural diagram of a door lock protection device provided by an exemplary embodiment of the present invention;

[0037] Figure 2 A circuit block diagram of a door lock protection device provided by an exemplary embodiment of the present invention;

[0038] Figure 3 A protection logic timing diagram of a NOT gate and AND gate array of a door lock protection device provided by an exemplary embodiment of the present invention;

[0039] Figure 4 A door opening protection logic timing diagram of a door lock protection device provided by an exemplary embodiment of the present invention;

[0040] Figure 5 A PWM output delay logic timing diagram of a door lock protection device provided by an exemplary embodiment of the present invention;

[0041] Figure 6 A protection logic timing diagram of a door lock bad closing state of a door lock protection device provided by an exemplary embodiment of the present invention;

[0042] Figure 7 A flow chart of a door lock protection device provided by an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0043] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0044] Example 1

[0045] Figure 1 A schematic diagram of a door lock protection device provided by an exemplary embodiment of the present invention is applied to an electrical device, which includes a door lock, a drive control circuit, a power circuit and a load. Figure 1 The structure of the door lock protection device includes a door lock 1, a door lock switch detection circuit 2, a power-off detection circuit 3, a drive control circuit 4, and a logic circuit 5. The power-off detection circuit 3 is respectively connected to the door lock switch detection circuit 2, the logic circuit 5, and the drive control circuit 4. The drive control circuit 4 is connected to the power circuit 6 through the logic circuit 5, and the load 7 is connected to the power circuit 6. The door lock switch detection circuit 2 detects the switch state of the door lock and outputs the switch state signal of the door lock to the power-off detection circuit 3. The switch state includes an unlock state and a locked state. The switch state signal is used to characterize the door lock switch state, and the unlock state and the locked state are distinguished by high and low levels.

[0046] The power-off detection circuit 3 determines that the door lock is unlocked when the electrical device is operating according to the switch state signal, and outputs a power-off signal to the logic circuit 5 .

[0047] The logic circuit 5 converts the level signal output by the drive control circuit 4 into a target level signal, and outputs the target level signal to the power circuit 6 .

[0048] The target level signal is used to drive the power circuit 6 to stop supplying power to the load 7. The target level can be a high level or a low level, which is set according to the working mechanism of the power circuit. The load 7 in the embodiment of the present invention is generally a high voltage load. When the power circuit supplies power to the load, the load operates. When the power circuit stops supplying power to the load, the load stops operating.

[0049] Current electrical equipment generally has door lock protection measures, that is, when the door lock of the electrical equipment is unlocked, the power supply to the high-voltage load is stopped to ensure user safety. However, when the drive control circuit or other related components fail, or there is residual power in the capacitor contained in the circuit, the door lock protection measures will fail, and the high-voltage load of the electrical equipment will still operate, posing a safety hazard.

[0050] Based on this, the embodiment of the present invention detects the switch state of the door lock, and when it is determined that the door lock is in the unlocked state, uses logic control to forcibly set the level state of the input power circuit to drive the power circuit to stop supplying power to the load, thereby solving the problem of potential safety hazards caused by the user suddenly opening the door while the electrical equipment is in use and the electrical equipment is still running, thereby improving the safety and reliability of the electrical equipment.

[0051] The working principle of the door lock protection device is explained below.

[0052] When the electrical equipment is running and the door lock is suddenly opened, that is, the door lock is unlocked, the door lock switch detection circuit will send the door lock status signal corresponding to the door lock status at this time to the power-off detection circuit; after the power-off detection circuit detects that the circuit is powered off according to the door lock status signal, it will send the power-off signal to the logic circuit; the logic circuit converts the level signal output by the drive control circuit into a target level signal, and outputs the target level signal to the power circuit; after receiving the target circuit signal, the power circuit will force the load to stop supplying power, and the load will stop running. Using the logic circuit to convert the level output by the drive control circuit can prevent safety hazards caused by circuit failure or delay in the release level of the capacitor.

[0053] When the electrical equipment operates normally and the door lock is in a locked state, the drive control circuit drives the power circuit to supply power to the load, and the load operates normally.

[0054] In one embodiment, see Figure 2 The drive control circuit includes a drive chip 24; the power circuit includes an intelligent power module 25; the logic circuit includes a NOT gate U6 and an AND gate array U7; the input end of the NOT gate U6 is respectively connected to the output end of the power-off detection circuit 3 and the power control end I2 of the drive chip 24, the output end of the NOT gate U6 is connected to the first input end of each AND gate included in the gate array U7, the second input end of each AND gate is connected to a first power drive pin (UL, UH, VL, VH, WL, WH) corresponding to the drive chip, and the output end of each AND gate is connected to a second power drive pin (UL, UH, VL, VH, WL, WH) corresponding to the intelligent power module 25.

[0055] It should be noted that the number of the first power drive pins of the driver chip and the number of the second power drive pins of the intelligent power module are determined according to the power supply requirements of the load, and the first power drive pins and the second power drive pins are not limited to Figure 2 6 shown.

[0056] In one embodiment, when a low level is input to the power control terminal I2 of the driver chip 24, the driver chip 24 outputs a first power signal to the intelligent power module 25 to drive the intelligent power module 25 to supply power to the load. When a high level is input to the power control terminal I2 of the driver chip 24, the driver chip 24 outputs a second power signal (target level signal) to the intelligent power module 25, and the intelligent power module 25 stops supplying power to the load.

[0057] Generally, when the door lock is unlocked, the power control terminal I2 of the driver chip 24 switches from a high level to a low level, and the driver chip 24 outputs a second power signal to the intelligent power module 25 to drive the intelligent power module 25 to stop supplying power to the load. If the driver chip 24 fails, the driver chip 24 may still output the first power signal to the intelligent power module 25 even if the door lock is unlocked; or the capacitor in the circuit (e.g. Figure 2 The residual power in the capacitors C1 and C2 causes the power control terminal I2 of the driver chip 24 to fail to switch from a high level to a low level in time. Even if the door lock is unlocked, the driver chip 24 may still output the first power signal to the intelligent power module 25. For the above two situations, there is a risk that the door lock is unlocked and the load is still running, which poses a safety hazard.

[0058] In the embodiment of the present invention, it can be ensured that when the door lock is unlocked, the power signal output by the driver chip 24 is converted into a second power signal (target level signal) through the NOT gate U6 and the AND gate array U7, and output to the intelligent power module 25, so that the intelligent power module 25 stops supplying power to the load in a timely and effective manner to ensure user safety.

[0059] It should be noted that, in another embodiment, when the power control terminal I2 of the driver chip 24 inputs a low level, the driver chip 24 outputs a first power signal to the intelligent power module 25 to drive the intelligent power module 25 to supply power to the load. When the power control terminal I2 of the driver chip 24 inputs a high level, the driver chip 24 outputs a second power signal (target level signal) to the intelligent power module 25, and the intelligent power module 25 stops supplying power to the load. In this embodiment, the logic circuit is adaptively adjusted according to the control mechanism of the driver chip 24.

[0060] In one embodiment, see Figure 2, the load is a three-phase load, for example, the three-phase load is a motor 26; therefore, the AND gate array U7 includes 6 AND gates; the intelligent power module 25 includes 6 second power drive pins (UL, UH, VL, VH, WL, WH) and a three-phase power supply output terminal (U, V, W); the output terminal of each AND gate is connected to a corresponding second power drive pin (UL, UH, VL, VH, WL, WH); UL, UH, VL, VH, WL, WH correspond to six PWM outputs, which are used to control the three-phase power supply output terminal (U, V, W). The three-phase power supply output terminal (U, V, W) is connected to the input terminal of the motor 26. Using a three-phase power supply output will reduce the current fluctuation, so the output of the load will be more stable.

[0061] In the embodiment of the present invention, it can be ensured that when the door lock is unlocked, the gate array U7 immediately forces the PWM output to be blocked and the motor stops running.

[0062] In one embodiment, see Figure 2 The door lock switch detection circuit includes: an optocoupler device U1, a switch tube 22 and a voltage conversion subcircuit 27; the input end of the voltage conversion subcircuit 27 is connected to the output end of the switch tube 22, and the input end of the switch tube 22 is connected to the power supply; the input end and the control end of the switch tube 22 are also connected to the output end of the optocoupler device U1, and the input end of the optocoupler device U1 is connected to the door lock; the optocoupler device U1 is used to detect the switch state of the door lock; when the switch state of the door lock is the locked state, the switch tube 22 is turned on; when the switch state of the door lock is the unlocked state, the switch tube 22 is turned off. The door lock switch detection circuit can accurately detect the state of the door lock and output the door lock state signal.

[0063] Figure 3 A protection logic timing diagram of a NOT gate and AND gate array of a door lock protection device provided by an exemplary embodiment of the present invention is shown below in conjunction with Figure 3 and Figure 4 Taking the electrical equipment as a dishwasher and the load as a spray arm motor as an example, the control mechanism of the door lock protection device is further explained.

[0064] When the dishwasher is running and the door is closed, that is, the door lock is locked, the switch tube 22 is turned on, the voltage conversion circuit inputs 0V voltage to I2, and the power control terminal I2 of the driver chip 24 inputs a low level. The NOT gate and the AND gate array will convert the low level into a high level and input it to the intelligent power module, driving the intelligent power module to power the spray arm motor, and the spray arm motor runs.

[0065] When the dishwasher is running and the door is open, the power-off detection circuit 3 detects that the door lock is unlocked, the switch tube 22 is turned off, the 5V pull-up circuit of the voltage conversion circuit inputs a 5V voltage to I2, the NOT gate converts the high level of the power control terminal I2 into a low level, and the AND gate array converts the high level signal output by the drive control circuit into a target level signal (low level), and outputs the target level signal to the power circuit to drive the power circuit to stop supplying power to the spray arm motor, and the spray arm motor stops running.

[0066] In one embodiment, see Figure 2 , the optocoupler device U1 includes an optocoupler device diode 29 and an optocoupler device transistor 28; the cathode of the optocoupler device diode 29 is connected to the door lock 1, and the anode of the optocoupler device diode 29 is connected to the active control circuit 23 through the first resistor R1; the optocoupler device transistor 28 is connected to the switch tube 22 through the second resistor R7. The optocoupler device can effectively isolate the input and output circuits and will not be damaged when the input side is damaged by a strong voltage shock. Therefore, the use of the optocoupler device can make the door lock switch detection more accurate.

[0067] In one embodiment, the switch tube 22 is a triode; the base of the triode is connected to the optocoupler device U1 through the second resistor R7; the emitter of the triode is short-circuited with the base and connected to the power supply through the third resistor; the collector of the triode is connected to the voltage conversion subcircuit 27. The triode includes but is not limited to a pnp triode.

[0068] The transistor can control a larger change in collector current with a small change in base current, thus enabling more accurate detection of the door lock switch state.

[0069] In one embodiment, the voltage conversion subcircuit includes a first capacitor, a second capacitor, a first voltage-stabilizing integrated circuit, and a second voltage-stabilizing integrated circuit; the input end of the second capacitor is connected to the first capacitor, the first voltage-stabilizing integrated circuit, and the second voltage-stabilizing integrated circuit respectively, and the output end of the second capacitor is connected to the power-off detection circuit. Because of the voltage-stabilizing integrated circuit and the capacitor, the voltage conversion subcircuit can stabilize the output voltage of the power supply circuit to ensure that the circuit can work normally.

[0070] In the embodiment of the present invention, a door is used to cut off the power supply of the microcontroller on the driving side, and the driving microcontroller adds a power failure monitoring mechanism for the power supply voltage. If a power failure is detected, the six PWM outputs corresponding to the spray arm motor driving circuit are immediately blocked. In addition, a NOT gate and an AND gate array circuit are added, so that the PWM output can be blocked even when the driving microcontroller fails. The present invention solves the problem that when the dishwasher door is suddenly opened during washing, the hot water on the spray arm will be directly sprayed out, causing burns to the user, and adds a protection function for the driving chip when the driving side suddenly loses power, thereby improving safety and user experience.

[0071] In one embodiment, in combination Figure 2 The power-off detection circuit includes a diode D1 and a fourth resistor R11; the input end of the diode D1 is connected to the door lock switch detection circuit, and the output end of the diode D1 is respectively connected to the input end of the logic circuit and the drive control circuit; the fourth resistor R11 is respectively connected to the output end of the diode D1 and the door lock switch detection circuit. The power-off detection circuit can detect whether the circuit has a power-off condition, and send a power-off signal to the logic circuit, which can better stop the motor from running when the circuit has a power-off condition.

[0072] In one embodiment, the device also includes an active control circuit and a communication circuit; the output end of the active control circuit is connected to the drive control circuit through the communication circuit; the input end of the active control circuit is connected to the door lock switch detection circuit through a third resistor.

[0073] In one embodiment, the active control circuit 23 includes a main control MCU.

[0074] See also Figure 2 The door switch (door lock) is placed on one side of the active control circuit 23, one end of the door switch is connected to the main control side ground loop, and the other end is connected to the cathode of the optocoupler U1 diode, the anode of the optocoupler diode is connected to one end of the resistor R1, the other end of the resistor R1 is connected to the control pin of the main control MCU, the emitter of the optocoupler U1 transistor is connected to the drive side ground loop, the collector side of the optocoupler transistor is connected to one end of the resistor R7, the other end of the resistor R7 is connected to the base of the drive side power control pnp transistor, wherein the base and emitter of the transistor are short-circuited, and the emitter is pulled up to the drive side control voltage through a resistor.

[0075] Figure 5 A PWM output delay logic timing diagram of a door lock protection device provided by an exemplary embodiment of the present invention;

[0076] When the door is closed and the input current I2 port of the driver controller MCU is just connected, it is necessary to wait for a period of time to allow the input voltage (M5V) of the driver controller MCU and the upper bridge output of the three pins UH, VH, and WH of the driver controller MCU. The time range is [0.8s, 1.2s]. Preferably, it takes 1s to allow 6-way PWM output;

[0077] In addition to the door open and door closed states, the door lock also has a poor pull-in state; this poor pull-in state will cause the power control port level of the drive control circuit to change too frequently, so Figure 6 A protection logic timing diagram of a door lock poor closing state of a door lock protection device provided by an exemplary embodiment of the present invention.

[0078] When the door lock does not close properly, the input voltage M5V of the drive controller MCU and the input current I2 port of the drive controller MCU will change too frequently. When the number of changes is greater than n times (n can be set according to actual conditions), the three pins UH, VH, and WH of the drive controller MCU must be immediately blocked, and the input voltage M5V of the drive controller MCU will be delayed to turn on the interrupt, and the input current I2 port of the drive controller MCU will turn off the external interrupt. After waiting for a while, turn on the input port interrupt function of the drive control circuit. The time range is [1ms, 3ms]. Preferably, 2ms is taken. When the input port interrupt function of the drive control circuit is turned off, the 6-channel PWM output of the drive control circuit is cut off. Among them, the target level can be a high level or a low level, which is set according to the properties of the power circuit.

[0079] Figure 7 A flow chart of a door lock protection device provided by an exemplary embodiment of the present invention.

[0080] When the door lock is closed, a delay of 1s allows the PWM output to be driven;

[0081] When the power control port is at a high level, the NOT gate and the AND gate array forcefully shut down the driving PWM output and perform rising edge detection on the power control port; when the power control port is not at a high level, the power control port level jump detection is performed directly;

[0082] When the power control port level jump detection passes; the controller external interrupt is driven to turn off the PWM output; then a delay of 2ms is made to turn on the external interrupt, allowing the PWM output, and finally determining whether it is finished; when the power control port detection fails; directly determining whether it is finished.

[0083] Example 2

[0084] The embodiment of the present invention further provides a household appliance, which includes any one of the door lock protection devices, including but not limited to a dishwasher, an oven, a microwave oven, an electric rice cooker, and a pressure cooker.

[0085] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A door lock protection device, characterized in that: Applicable to electrical equipment, the electrical equipment includes a door lock, a drive control circuit, a power circuit and a load; the door lock protection device includes a door lock switch detection circuit, a power failure detection circuit and a logic circuit; the power failure detection circuit is respectively connected to the door lock switch detection circuit, the logic circuit and the drive control circuit; the drive control circuit is connected to the power circuit through the logic circuit; and the load is connected to the power circuit; The door lock switch detection circuit detects the switch state of the door lock and outputs the switch state signal of the door lock to the power failure detection circuit; The power-off detection circuit determines, based on the switch state signal, that the door lock is unlocked when the electrical device is operating, and outputs a power-off signal to the logic circuit; The logic circuit converts the level signal output by the drive control circuit into a target level signal, and outputs the target level signal to the power circuit; The target level signal is used to drive the power circuit to stop supplying power to the load.

2. The device according to claim 1, wherein The drive control circuit includes a drive chip; the power circuit includes an intelligent power module; the logic circuit includes a NOT gate and an AND gate array; The input end of the NOT gate is connected to the output end of the power-off detection circuit and the power control end of the driver chip respectively, the output end of the NOT gate is connected to the first input end of each AND gate included in the AND gate array, the second input end of each AND gate is connected to a first power drive pin corresponding to the driver chip, and the output end of each AND gate is connected to a second power drive pin corresponding to the intelligent power module.

3. The device according to claim 2, wherein The load includes a motor; the AND gate array includes 6 AND gates; the intelligent power module includes 6 second power drive pins and a three-phase power supply output terminal; The output end of each AND gate is connected to a corresponding second power drive pin; The three-phase power supply output end is connected to the input end of the motor.

4. The device according to claim 1, wherein The door lock switch detection circuit includes: an optocoupler device, a switch tube and a voltage conversion subcircuit; The input end of the voltage conversion sub-circuit is connected to the output end of the switch tube, and the input end of the switch tube is connected to the power supply; the input end and the control end of the switch tube are also connected to the output end of the optocoupler device, and the input end of the optocoupler device is connected to the door lock; The optocoupler device is used to detect the switch state of the door lock; When the door lock is in a locked state, the switch tube is turned on; when the door lock is in an unlocked state, the switch tube is turned off.

5. The device according to claim 4, characterized in that The optocoupler device includes an optocoupler diode and an optocoupler triode; The cathode of the optocoupler diode is connected to the door lock, and the anode of the optocoupler diode is connected to the first resistor; The optocoupler transistor is connected to the switch tube via a second resistor.

6. The device according to claim 4, characterized in that The switching tube includes a triode; The base of the transistor is connected to the optocoupler device via a second resistor; The emitter and base of the transistor are short-circuited and connected to the power supply via a third resistor; The collector of the triode is connected to the voltage conversion sub-circuit.

7. The device according to claim 4, wherein The voltage conversion subcircuit includes a first capacitor, a second capacitor, a first voltage stabilizing integrated circuit and a second voltage stabilizing integrated circuit; The input end of the second capacitor is connected to the first capacitor, the first voltage stabilizing integrated circuit and the second voltage stabilizing integrated circuit respectively, and the output end of the second capacitor is connected to the power-off detection circuit.

8. The device according to claim 1, wherein The power-off detection circuit includes a diode and a fourth resistor; The input end of the diode is connected to the door lock switch detection circuit, and the output end of the diode is connected to the input end of the logic circuit and the drive control circuit respectively; The fourth resistor is connected to the output end of the diode and the door lock switch detection circuit respectively.

9. The device according to claim 1, wherein The device also includes an active control circuit and a communication circuit; The output end of the active control circuit is connected to the drive control circuit via a communication circuit; The input end of the active control circuit is connected to the door lock switch detection circuit through a third resistor.

10. A household appliance, characterized in that: The household appliance includes the door lock protection device according to any one of claims 1 to 9.

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