Washing machine, power failure protection device of clutch and control method

Abstract

The invention discloses a washing machine, a clutch power-down protection device and a control method, a working voltage of a clutch and a voltage of a clutch control circuit are monitored through a detection circuit, and when a controller controls the clutch not to work, the detection circuit outputs a first control level signal to a motor control module; the operation state of the motor control module is controlled by the controller, when the controller controls the clutch to be powered on to work and the working voltage of the clutch is normal, the detection circuit outputs a first control level signal to the motor control module, the operation state of the motor control module is controlled by the controller, and when the working voltage of the clutch is abnormal, the detection circuit outputs a second control level signal to the motor control module. The detection circuit outputs a second control level signal to the motor control module, the motor control module controls the motor to stop running and enables the motor to enter a protection state, the controller does not need to carry out software judgment control, control over the motor can be achieved through the hardware detection circuit, and timeliness and anti-interference performance are greatly improved; whether the clutch is powered down is directly detected, and the clutch power-down detection accuracy is high.

Description

Technical Field

[0001] The present invention belongs to the technical field of washing machines, and in particular, relates to a washing machine, a clutch power-off protection device and a control method. Background Art

[0002] During the washing process, the motor of the washing machine has two operating states: 1. In the washing state, the motor controls the inner drum of the washing machine to rotate forward and reverse periodically, and the motor runs at a speed of about 100 rpm; 2. In the dehydration state, the motor controls the inner drum of the washing machine to run at high speed in one direction to shake off most of the water in the clothes, and the motor runs at a speed of 800-1000 rpm. When the washing machine switches from the washing state to the dehydration state, it is necessary to stop the motor first, pull up the clutch, and then control the motor to speed up to the target speed. If the clutch is pulled up during the operation of the motor, it is easy to cause damage to the clutch.

[0003] During the dehydration process of the washing machine, if the L and N circuits lose power for a short time due to poor socket contact, vibration of the washing machine, or human contact, the clutch will lose power for a short time, and the clutch will return to its original position and be pulled up again. Because the power-off time is very short, the motor will continue to run at high speed, and the clutch will be easily damaged during this process.

[0004] The existing technology monitors L and N (AC with voltage of 220V and frequency of 50Hz) on the power board of the washing machine (zero-crossing detection circuit). When L and N are normally connected to the washing machine, the detection circuit will output a square wave signal with a period of 20ms to the MCU; when L and N are abnormally connected, the detection circuit will continuously output a high level to the MCU; when the MCU receives an abnormal signal (continuous high level), it will send a stop command to the motor control module to achieve the protection function.

[0005] The existing control method is to transmit the detection signal to the MCU, which judges the received signal and issues instructions to the motor control module if it is an abnormal signal. The disadvantages of this control method are as follows: 1. The detection circuit detects the voltage L1 and N at the clutch end, not the voltage N at the clutch end. Instead, it detects the voltage L and N at the input end of the control board. In the event that the power grid is not cut off and the clutch is powered off, the power-off condition of the clutch cannot be truly detected.

[0006] 2. Time delay: The MCU's judgment is based on software control logic, which will cause time delay.

[0007] 3. It is easy to be interfered with. When the MCU is interfered with, it may make wrong judgments and issue wrong control instructions.

[0008] The above information disclosed in the background technology is only used to increase the understanding of the background technology of the present application, and therefore, it may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0009] The present invention proposes a washing machine, a clutch power-off protection device and a control method to solve the technical problems that the existing washing machine has poor accuracy in detecting clutch power-off and there is delay and interference in judging whether the clutch has power-off by the software of the controller.

[0010] In order to achieve the above invention / design purpose, the present invention adopts the following technical solutions: A power-off protection device for a washing machine clutch, the device comprising: A motor control module, used to control the running state of the motor; clutch; A clutch control circuit, comprising a power-on switch, wherein the power-on switch is used to be controlled to be turned on to power on the clutch or controlled to be turned off to power off the clutch; The device also includes: A detection circuit, used for detecting the working voltage of the clutch and the voltage of the clutch control circuit and outputting a control level signal to the motor control module; A controller, configured to output control signals to the clutch control circuit and the motor control module; The controller outputs a power-on control signal to the clutch control circuit, the clutch control circuit is a first voltage, and the power-on switch is turned on; the detection circuit detects the working voltage of the clutch and outputs a control level signal to the motor control module, when the detection circuit outputs a first control level signal to the motor control module, the motor control module controls the running state of the motor according to the control signal of the controller; when the detection circuit outputs a second control level signal to the motor control module, the motor control module controls the motor to stop running; The controller does not output a power-on control signal to the clutch control circuit, the clutch control circuit is at a second voltage, and the power-on switch is disconnected; the detection circuit detects the second voltage of the clutch control circuit and outputs a first control level signal to the motor control module, and the motor control module controls the operating state of the motor according to the control signal of the controller.

[0011] As described above, the power-off protection device for the washing machine clutch, the clutch control circuit includes a voltage-dividing resistor, a first switch, a power supply and a diode, the driving end of the first switch is connected to the controller through the voltage-dividing resistor, the switch end of the first switch is respectively connected to the ground and the positive electrode of the diode, the negative electrode of the diode is connected to the power supply, the power-on switch is connected between the power supply and the positive electrode of the diode, and the voltage of the clutch control circuit is the voltage at the positive electrode of the diode.

[0012] The power-off protection device for the washing machine clutch as described above, the detection circuit comprises: A rectifier circuit, used for receiving and rectifying the working voltage of the clutch; The switch circuit is used to receive the rectified signal of the rectifier circuit, to receive the voltage of the clutch control circuit, and to output a first control level signal or a second control level signal to the motor control module according to the rectified signal and the voltage of the clutch control circuit.

[0013] In the power-off protection device for the clutch of the washing machine as described above, an isolation element is provided between the rectifier circuit and the switch circuit, the isolation element is a photocoupler, and a protection diode is connected in series to the input end of the photocoupler.

[0014] In the power-off protection device for the clutch of the washing machine as described above, a level conversion circuit is arranged between the isolation element and the switching circuit, and the level conversion circuit includes a fourth switch, a power supply, and a voltage-dividing resistor. The first output end of the photocoupler is connected to the power supply through a voltage-dividing resistor connected in series, and the second output end is grounded. The driving end of the fourth switch is connected between the voltage-dividing resistors, and the switch ends of the fourth switch are respectively connected to the power supply and the switching circuit.

[0015] As described above, the power-off protection device for the washing machine clutch, the switch circuit includes an RC filter circuit, a second switch, a third switch, a voltage-dividing resistor and a power supply; the voltage-dividing resistor is connected in series between the power supply and the ground; the driving end of the second switch is connected to the RC filter circuit, the switch ends of the second switch are respectively grounded and connected to the power supply through a voltage-dividing resistor; the driving end of the second switch is connected between the voltage-dividing resistors, and the switch ends of the second switch are respectively grounded and connected to the motor control module.

[0016] In the power-off protection device for the clutch of the washing machine as described above, the voltage of the clutch control circuit is connected to the RC filter circuit through a diode and is grounded through a resistor.

[0017] In the power-off protection device for the clutch of the washing machine as described above, the detection circuit is connected to both sides of the coil of the clutch, and the detection circuit outputs a control level signal to the controller.

[0018] A washing machine comprises the above-mentioned power-off protection device for the washing machine clutch.

[0019] A control method for a washing machine is as follows: The controller does not output a power-on control signal to the clutch control circuit, the clutch control circuit is at a second voltage, and the power-on switch is disconnected; the detection circuit detects the second voltage of the clutch control circuit and outputs a first control level signal to the motor control module, and the motor control module controls the running state of the motor according to the control signal of the controller; The controller outputs a power-on control signal to the clutch control circuit, the clutch control circuit is a first voltage, and the power-on switch is turned on; the detection circuit outputs a first control level signal to the motor control module, and the motor control module controls the operating state of the motor according to the control signal of the controller; when the detection circuit outputs a second control level signal to the motor control module, the motor control module controls the motor to stop running.

[0020] Compared with the prior art, the advantages and positive effects of the present invention are: The power-off protection device of the clutch of the washing machine of the present invention comprises a motor control module, a clutch, a clutch control circuit, a detection circuit and a controller; the motor control module is used for controlling the running state of the motor; the clutch control circuit has a power-on switch, and the power-on switch is used for controlled conduction to power on the clutch or controlled disconnection to power off the clutch; the detection circuit is used for detecting the working voltage of the clutch and the voltage of the clutch control circuit and outputting a control level signal to the motor control module; the controller is used for outputting a control signal to the clutch control circuit and the motor control module; the controller outputs a power-on control signal to the clutch control circuit, the clutch control circuit is a first voltage, and the power-on switch is turned on; the detection circuit detects the working voltage of the clutch and outputs a control level signal to the motor control module, when the detection circuit outputs the first control level signal to the motor control module, the motor control module controls the running state of the motor according to the control signal of the controller; when the detection circuit outputs a second control level signal to the motor control module, the motor control module controls the motor to stop running; the controller does not output the power-on control signal to the clutch control circuit, the clutch control circuit is a second voltage, and the power-on switch is turned off; the detection circuit detects the second voltage of the clutch control circuit and outputs the first control level signal to the motor control module, and the motor control module controls the running state of the motor according to the control signal of the controller. The present invention directly detects whether the clutch loses power, and the clutch power-off detection has high accuracy; the present invention monitors the working voltage of the clutch and the voltage of the clutch control circuit through a detection circuit. When the controller controls the clutch not to work, the detection circuit outputs a first control level signal to the motor control module, and the running state of the motor control module is controlled by the controller. When the controller controls the clutch to power on and work, when the working voltage of the clutch is normal, the detection circuit outputs a first control level signal to the motor control module, and the running state of the motor control module is controlled by the controller. When the working voltage of the clutch is abnormal, the detection circuit outputs a second control level signal to the motor control module, and the motor control module controls the motor to stop running and put the motor into a protection state. The present invention does not require the controller to perform software judgment and control, and the motor control can be realized through a hardware detection circuit, which greatly improves timeliness and anti-interference.

[0021] The washing machine of the present invention comprises a clutch power-off protection device, which comprises a motor control module, a clutch, a clutch control circuit, a detection circuit and a controller; the motor control module is used to control the running state of the motor; the clutch control circuit has a power-on switch, which is used to be controlled to be turned on to power on the clutch or controlled to be turned off to power off the clutch; the detection circuit is used to detect the working voltage of the clutch and the voltage of the clutch control circuit and output a control level signal to the motor control module; the controller is used to output a control signal to the clutch control circuit and the motor control module; the controller outputs a power-on control signal to the clutch control circuit, the clutch control circuit is a first voltage, and the power-on The switch is turned on; the detection circuit detects the working voltage of the clutch and outputs a control level signal to the motor control module. When the detection circuit outputs a first control level signal to the motor control module, the motor control module controls the running state of the motor according to the control signal of the controller; when the detection circuit outputs a second control level signal to the motor control module, the motor control module controls the motor to stop running; the controller does not output a power-on control signal to the clutch control circuit, the clutch control circuit is the second voltage, and the power-on switch is disconnected; the detection circuit detects the second voltage of the clutch control circuit and outputs a first control level signal to the motor control module, and the motor control module controls the running state of the motor according to the control signal of the controller. The present invention directly detects whether the clutch loses power, and the clutch power-off detection has high accuracy; the present invention monitors the working voltage of the clutch and the voltage of the clutch control circuit through a detection circuit. When the controller controls the clutch not to work, the detection circuit outputs a first control level signal to the motor control module, and the running state of the motor control module is controlled by the controller. When the controller controls the clutch to power on and work, when the working voltage of the clutch is normal, the detection circuit outputs a first control level signal to the motor control module, and the running state of the motor control module is controlled by the controller. When the working voltage of the clutch is abnormal, the detection circuit outputs a second control level signal to the motor control module, and the motor control module controls the motor to stop running and put the motor into a protection state. The present invention does not require the controller to perform software judgment and control, and the motor control can be realized through a hardware detection circuit, which greatly improves timeliness and anti-interference.

[0022] The control method of the washing machine of the present invention is as follows: the controller does not output a power-on control signal to the clutch control circuit, the clutch control circuit is at the second voltage, the power-on switch is disconnected, the detection circuit detects the second voltage of the clutch control circuit and outputs a first control level signal to the motor control module; the controller outputs a power-on control signal to the clutch control circuit, the clutch control circuit is at the first voltage, the power-on switch is turned on, the detection circuit outputs a first control level signal to the motor control module, the motor control module is controlled by the controller, and when the detection circuit outputs a second control level signal to the motor control module, the motor control module controls the motor to stop running. The present invention monitors the working voltage of the clutch and the voltage of the clutch control circuit through a detection circuit. When the controller controls the clutch not to work, the detection circuit outputs a first control level signal to the motor control module, and the operating state of the motor control module is controlled by the controller. When the controller controls the clutch to power on and work, when the working voltage of the clutch is normal, the detection circuit outputs a first control level signal to the motor control module, and the operating state of the motor control module is controlled by the controller. When the working voltage of the clutch is abnormal, the detection circuit outputs a second control level signal to the motor control module, and the motor control module controls the motor to stop running and put the motor into a protection state. The control method of the present invention does not require the controller to perform software judgment and control, and the control of the motor can be achieved through a hardware detection circuit, which greatly improves timeliness and anti-interference.

[0023] After reading the specific embodiments of the present invention in conjunction with the accompanying drawings, other features and advantages of the present invention will become more clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a principle block diagram of a specific embodiment of the present invention.

[0026] Figure 2 Detailed description of the invention The figure is a circuit diagram of a clutch control circuit according to a specific embodiment of the invention.

[0027] Figure 3 Detailed description of the invention

[0028] Figure 4 It is a circuit diagram of a controller and a motor control module according to a specific embodiment of the present invention.

[0029] Figure 5 It is a flow chart of a control method according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying 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, should not be understood as a limitation on the present invention.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In the description of the implementation method, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0033] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0034] In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0035] The power-off protection device of the washing machine clutch directly detects the working voltage of the clutch and can accurately detect whether the clutch has lost power. When the clutch loses power, the motor is directly controlled through the hardware detection circuit, which greatly improves the timeliness and anti-interference of power-off detection.

[0036] The power-off protection device of the clutch of the washing machine comprises a motor control module, a clutch, a clutch control circuit, a detection circuit and a controller; the motor control module is used to control the running state of the motor; the clutch control circuit has a power-on switch, and the power-on switch is used to control the on-state to power on the clutch or control the off-state to power off the clutch; the detection circuit is used to detect the working voltage of the clutch and the voltage of the clutch control circuit and output a control level signal to the motor control module; the controller is used to output a control signal to the clutch control circuit and the motor control module; the controller outputs a power-on control signal to the clutch control circuit, the clutch control circuit is a first voltage, and the power-on switch is turned on; the detection circuit detects the working voltage of the clutch voltage and outputs a control level signal to the motor control module. When the detection circuit outputs a first control level signal to the motor control module, the motor control module controls the running state of the motor according to the control signal of the controller; when the detection circuit outputs a second control level signal to the motor control module, it indicates that the clutch is powered off, and the motor control module controls the motor to stop running and enter the power-off protection state; the controller does not output a power-on control signal to the clutch control circuit, the clutch control circuit is the second voltage, and the power-on switch is disconnected; the detection circuit detects the second voltage of the clutch control circuit and outputs a first control level signal to the motor control module, and the motor control module controls the running state of the motor according to the control signal of the controller.

[0037] exist Figure 1 In the example, the power-off protection device of the washing machine clutch includes a motor control module, a clutch, a clutch control circuit, a detection circuit and a controller.

[0038] The motor is used to drive the pulsator to rotate or drive the pulsator and the inner tub to rotate to complete different washing processes: washing, dehydration and other processes.

[0039] The motor control module HVIC is used to control the running state of the motor. The Fo pin of the motor control module is set to zero level, and the motor control module enters the protection state.

[0040] The controller MCU is used to output a control signal to the motor control module, and the motor control module controls the running state of the motor according to the control signal output by the controller.

[0041] The clutch is used to realize the switching between the state of the motor driving the impeller and the state of the motor driving the impeller and the inner barrel.

[0042] The clutch has a coil L1 , and a voltage is applied to the coil L1 to control the state of the clutch.

[0043] The clutch control circuit has a power-on switch, which is used to be controlled to be turned on to power on the clutch or controlled to be turned off to power off the clutch.

[0044] The controller is used to output a control signal to the clutch control circuit to control the on and off of the power switch of the clutch control circuit, thereby powering on or off the clutch.

[0045] The detection circuit is used to detect the working voltage of the clutch and the voltage of the clutch control circuit and output a control level signal to the motor control module.

[0046] The controller outputs a power-on control signal to the clutch control circuit. The clutch control circuit is at a first voltage, the power-on switch is turned on, and the clutch is powered on and works. The detection circuit detects the working voltage of the clutch and outputs a control level signal to the motor control module. When the working voltage is normal, the detection circuit outputs a first control level signal to the motor control module, and the motor control module controls the running state of the motor according to the control signal of the controller. When the working voltage is abnormal and the clutch loses power, the detection circuit outputs a second control level signal to the motor control module, and the motor control module controls the motor to stop running and put the motor into a protection state. The controller does not output a power-on control signal to the clutch control circuit, the clutch control circuit is at the second voltage, the power-on switch is disconnected, and the clutch is powered off and does not work; the detection circuit detects the second voltage of the clutch control circuit and outputs a first control level signal to the motor control module, and the motor control module controls the operating state of the motor according to the control signal of the controller.

[0047] The working voltage of the clutch and the voltage of the clutch control circuit are monitored by the detection circuit. When the controller controls the clutch to be powered off and not working, the detection circuit outputs a first control level signal to the motor control module, and the operating state of the motor control module is controlled by the controller. When the controller controls the clutch to be powered on and working, when the working voltage of the clutch is normal, the detection circuit outputs a first control level signal to the motor control module, and the operating state of the motor control module is controlled by the controller. When the working voltage of the clutch is abnormally powered off, the detection circuit outputs a second control level signal to the motor control module, and the motor control module controls the motor to stop running and put the motor into a protection state. There is no need to perform software judgment and control through the controller, and the motor control can be achieved through the hardware detection circuit, which greatly improves the timeliness and anti-interference performance.

[0048] The detection circuit detects the AC signals on both sides of the clutch coil L1. The detection signal is not judged by the controller MCU, but is directly transmitted to the fault diagnosis FO pin of the motor control module, realizing the clutch power-off protection function from the hardware circuit.

[0049] The clutch control circuit includes a voltage-dividing resistor, a first switch N1, a power supply and a diode D1. The driving end of the first switch N1 is connected to the controller through the voltage-dividing resistor, the switch end of the first switch N1 is respectively connected to the ground and the positive electrode of the diode D1, the negative electrode of the diode D1 is connected to the power supply, the power-on switch K1 is connected between the power supply and the positive electrode of the diode D1, and the voltage of the clutch control circuit is the voltage RLY at the positive electrode of the diode D1.

[0050] exist Figure 2 In the example of , the clutch control circuit includes a voltage dividing resistor R1, a voltage dividing resistor R2, a first switch N1, a power supply and a diode D1.

[0051] The power supply is +12V.

[0052] The controller MCU outputs a control signal to the resistor R1 , and the resistor R1 is connected in series with the resistor R2 and then grounded.

[0053] The first switch N1 is an NPN transistor N1 , the base of the transistor N1 is connected between the resistor R1 and the resistor R2 , the collector of the transistor N1 is connected to the anode of the diode D1 , and the emitter of the transistor N1 is grounded.

[0054] The cathode of diode D1 is connected to the +12V power supply.

[0055] The power-on switch is relay K1, the induction part of relay K1 is connected between the +12V power supply and the positive pole of diode D1, the action part of relay K1 is connected in the power supply circuit of clutch coil L1, specifically, the action part of relay K1 and the clutch coil are connected in series between clutch power supplies AC_L and AC_N.

[0056] The voltage of the clutch control circuit is the voltage RLY at the anode of the diode D1.

[0057] The controller MCU controls the relay K1 to control the power on and off of the clutch. When the relay K1 is energized, the clutch is powered on, and when the relay K1 is disconnected, the clutch is powered off and reset.

[0058] The controller MCU outputs a high-level control signal to the clutch control circuit, the transistor N1 is turned on, the induction part of the relay K1 is energized to attract the action part, the relay K1 is closed and turned on, and the clutch is powered on.

[0059] The controller MCU does not output a control signal to the clutch control circuit, the transistor N1 is turned off, the induction part of the relay K1 loses power and the action part is disconnected, the relay K1 is disconnected, and the clutch is powered off.

[0060] The detection circuit includes a rectification circuit, an isolation element, a level conversion circuit and a switch circuit.

[0061] The rectifier circuit is used for receiving the working voltage of the clutch and rectifying it.

[0062] The switch circuit is used to receive the rectified signal of the rectifier circuit, and is also used to receive the voltage of the clutch control circuit, and output a first control level or a second control level signal to the motor control module according to the rectified signal and the voltage of the clutch control circuit.

[0063] An isolation element is provided between the rectifier circuit and the switch circuit. The isolation element is a photocoupler. A protection diode D10 is connected in series to the input end of the photocoupler.

[0064] A level conversion circuit is arranged between the isolation element and the switch circuit, and the level conversion circuit includes a fourth switch N5, a power supply, a voltage-dividing resistor R23 and a voltage-dividing resistor R28. The first output end of the photocoupler is connected to the power supply through the resistor R23 and the resistor R28 connected in series, and the second output end is grounded. The driving end of the fourth switch N5 is connected between the resistor R23 and the resistor R28, and the switch end of the fourth switch N5 is respectively connected to the power supply and the switch circuit.

[0065] The switch circuit includes an RC filter circuit, a second switch N6, a third switch N7, a voltage-dividing resistor R24, a voltage-dividing resistor R35 and a power supply; the resistor R24 ​​and the resistor R35 are connected in series between the power supply and the ground; the driving end of the second switch N6 is connected to the RC filter circuit, and the switch ends of the second switch N6 are respectively grounded and connected to the power supply through the resistor R24; the driving end of the second switch N7 is connected between the resistor R24 ​​and the resistor R35, and the switch ends of the second switch N6 are respectively grounded and connected to the motor control module.

[0066] The voltage of the clutch control circuit is connected to the RC filter circuit through the diode D8 and to the ground through the resistor.

[0067] The detection circuit is connected to both sides of the coil of the clutch, the detection circuit outputs a control level signal to the controller, and the controller outputs a control signal to the motor control module.

[0068] exist Figure 3 In the example, AC_L and AC_N are respectively Figure 2 AC_L and AC_N are connected so that the detection circuit is connected to both sides of the coil L1 of the clutch.

[0069] exist Figure 3 In the example, a diode D9, a resistor R29, a resistor R30 and a resistor R13 are connected in series between AC_L and AC_N in sequence, AC_N is grounded, the positive electrode of the diode D9 is connected to AC_L, and the negative electrode is connected to the resistor R29 to achieve rectification.

[0070] A first input terminal of the photocoupler IC5 is connected between the resistor R30 and the resistor R33 , and a second input terminal of the photocoupler IC5 is connected to AC_N.

[0071] In order to protect the photocoupler IC5, a diode D10 is connected between the first input terminal and the second input terminal of the photocoupler IC5, the anode of the diode D10 is connected to the second input terminal of the photocoupler IC5, and the cathode of the diode D10 is connected to the first input terminal of the photocoupler IC5.

[0072] A first output terminal of the photocoupler IC5 is connected to a +12V power supply through a resistor R28 and a resistor R23 connected in series, and a second output terminal of the photocoupler IC5 is grounded.

[0073] The fourth switch N5 is a PNP transistor N5 , the base of the transistor N5 is connected between the resistor R28 and the resistor R23 , the emitter is connected to a +12V power supply, and the collector is grounded through a resistor R31 .

[0074] The switch circuit includes a resistor R25, a capacitor C6, a resistor R26, a capacitor C7, a resistor R27, a resistor R34, a second switch N6, a resistor R24, a resistor R35 and a third switch N7. The second switch N6 is an NPN transistor N6, and the third switch N7 is an NPN transistor N7.

[0075] Resistors R25, R26, R27 and R34 are connected in sequence between the collector of transistor N5 and ground, one end of capacitor C6 is connected between resistor R25 and resistor R26, and the other end is grounded, and one end of capacitor C7 is connected between resistor R26 and resistor R26, and the other end is grounded.

[0076] The +5V power supply is grounded through the series-connected resistors R24 and R35.

[0077] The base of transistor N6 is connected between resistor R27 and resistor R34, the emitter is grounded, and the collector is connected between resistor R24 ​​and resistor R35.

[0078] The base of transistor N7 is connected between resistor R24 ​​and resistor R35, the emitter is grounded, and the collector outputs the signal Line_JC to the Fo pin of the motor control module HIVC. At the same time, the collector output signal Line_JC of transistor N7 is sampled by the controller MCU. Figure 4 shown.

[0079] The voltage RLY of the clutch control circuit is connected between the resistor R31 and the resistor R25 through the resistor R22 and the diode D8. The anode of the diode D8 is connected to the resistor R22, and the cathode of the diode D8 is connected to the resistor R31 and the resistor R25.

[0080] When the controller MCU controls the clutch to power on, the photocoupler IC5 will be turned on and off at a frequency of 50Hz and a duty cycle of 50%, forming a 12V square wave. After filtering by the RC circuit, the transistor N6 is continuously turned on, the transistor N7 is turned off, and the Line_JC connected to the Fo pin of the motor control module HVIC is continuously high. Both the MCU and HVIC detect normal working signals. At this time, RLY is low and has no effect on the above judgment. If an abnormal situation occurs (AC_L, AC_N power failure), the photocoupler IC5 is cut off, the transistor N6 is turned off, the transistor N7 is turned on, the Line_JC connected to the Fo pin of the motor control module HVIC is pulled low, and enters the protection state, and the motor module controls the motor to stop running.

[0081] The controller MCU does not output the clutch control signal, RLY is at a high level, transistor N6 is continuously turned on, transistor N7 is disconnected, Line_JC is connected to the Fo pin of the motor control module HVIC, which is at a continuously high level, and both the controller MCU and the motor control module HVIC detect normal working signals.

[0082] For example, when the washing machine is in the dehydration state, the controller MCU controls the clutch to power on, and the photocoupler IC5 will be turned on and off at a frequency of 50Hz and a duty cycle of 50%, forming a 12V square wave. After filtering by the RC circuit, transistor N6 is continuously turned on, transistor N7 is turned off, and Line_JC is connected to the Fo pin of the motor control module HVIC, which is continuously at a high potential. Both MCU and HVIC detect normal working signals. At this time, the RLY network is a low circuit, which has no effect on the above judgment. If an abnormal situation occurs (AC_L, AC_N power failure), the photocoupler IC5 is cut off, transistor N6 is turned off, transistor N7 is turned on, and the Fo pin of the motor control module HVIC connected to Line_JC is pulled low, entering the protection state, and the motor module controls the motor to stop running; In the washing state of the washing machine, the controller MCU does not output the clutch control signal, RLY is at a high level, transistor N6 is continuously turned on, transistor N7 is disconnected, Line_JC is connected to the Fo pin of the motor control module HVIC at a continuously high level, and both the controller MCU and the motor control module HVIC detect normal working signals.

[0083] The power-off protection device of the washing machine clutch utilizes the self-protection function of the motor control module to connect the output signal of the clutch working voltage detection circuit to the Fo pin of the motor control module. When the clutch working power fails, the module Fo pin is set to zero level and the motor control module enters the protection state.

[0084] A washing machine comprises the above-mentioned power-off protection device for the washing machine clutch.

[0085] A control method for a washing machine: The controller does not output a power-on control signal to the clutch control circuit, the clutch control circuit is at the second voltage, and the power-on switch is disconnected; the detection circuit detects the second voltage of the clutch control circuit and outputs a first control level signal to the motor control module, and the motor control module controls the running state of the motor according to the control signal of the controller; The controller outputs a power-on control signal to the clutch control circuit, the clutch control circuit is at the first voltage, and the power-on switch is turned on; the detection circuit outputs a first control level signal to the motor control module, and the motor control module controls the running state of the motor according to the control signal of the controller; when the detection circuit outputs a second control level signal to the motor control module, the motor control module controls the motor to stop running.

[0086] For example, when the washing machine is in the washing state, the controller does not output the power-on control signal to the clutch control circuit, the clutch control circuit is at the second voltage, and the power-on switch is disconnected; the detection circuit detects the second voltage of the clutch control circuit and outputs the first control level signal (high level) to the motor control module, and the motor control module controls the running state of the motor according to the control signal of the controller; When the washing machine is in the dehydration state, the controller outputs a power-on control signal to the clutch control circuit, the clutch control circuit is at a first voltage, and the power-on switch is turned on; the detection circuit outputs a first control level signal (high level) to the motor control module, and the motor control module controls the running state of the motor according to the control signal of the controller; when the detection circuit outputs a second control level signal (low level) to the motor control module, the motor control module controls the motor to stop running.

[0087] exist Figure 5 In the example, the control method of the washing machine is: S1. Washing starts.

[0088] S2. The controller does not output a power-on control signal.

[0089] S3, the power switch is turned off, the detection circuit detects the second voltage of the clutch control circuit and outputs a first control level signal to the motor control module.

[0090] S4. The motor control module controls the running state of the motor according to the control signal of the controller.

[0091] S5. Dehydration begins.

[0092] S6. The controller outputs a power-on control signal.

[0093] S7, the power switch is turned on, the detection circuit detects the working voltage of the clutch and outputs a control level signal to the motor control module and the controller. If the control level signal is the first control level signal, the process proceeds to step S8, and if the control level signal is the second control level signal, the process proceeds to step S9.

[0094] S8. The motor control module controls the running state of the motor according to the control signal of the controller.

[0095] S9: The motor control module controls the motor to stop running.

[0096] The washing machine control method does not require a controller to perform software judgment and control, and the motor control can be realized through a hardware detection circuit, which greatly improves timeliness and anti-interference performance.

[0097] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to replace some of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions claimed to be protected by the present invention.

Claims

1. A power-off protection device for a washing machine clutch, the device comprising: A motor control module, used to control the running state of the motor; clutch; A clutch control circuit, comprising a power-on switch, wherein the power-on switch is used to be controlled to be turned on to power on the clutch or controlled to be turned off to power off the clutch; Characterized in that the device also includes: A detection circuit, used for detecting the working voltage of the clutch and the voltage of the clutch control circuit and outputting a control level signal to the motor control module; A controller, configured to output control signals to the clutch control circuit and the motor control module; The controller outputs a power-on control signal to the clutch control circuit, the clutch control circuit is a first voltage, and the power-on switch is turned on; the detection circuit detects the working voltage of the clutch and outputs a control level signal to the motor control module, when the detection circuit outputs a first control level signal to the motor control module, the motor control module controls the running state of the motor according to the control signal of the controller; when the detection circuit outputs a second control level signal to the motor control module, the motor control module controls the motor to stop running; The controller does not output a power-on control signal to the clutch control circuit, the clutch control circuit is at a second voltage, and the power-on switch is disconnected; the detection circuit detects the second voltage of the clutch control circuit and outputs a first control level signal to the motor control module, and the motor control module controls the operating state of the motor according to the control signal of the controller.

2. The power-off protection device for a washing machine clutch according to claim 1, characterized in that: The clutch control circuit includes a voltage-dividing resistor, a first switch, a power supply and a diode. The driving end of the first switch is connected to the controller through the voltage-dividing resistor, the switch end of the first switch is respectively connected to the ground and the positive electrode of the diode, the negative electrode of the diode is connected to the power supply, the power-on switch is connected between the power supply and the positive electrode of the diode, and the voltage of the clutch control circuit is the voltage at the positive electrode of the diode.

3. The power-off protection device for a washing machine clutch according to claim 1, characterized in that: The detection circuit comprises: A rectifier circuit, used for receiving and rectifying the working voltage of the clutch; The switch circuit is used to receive the rectified signal of the rectifier circuit, to receive the voltage of the clutch control circuit, and to output a first control level signal or a second control level signal to the motor control module according to the rectified signal and the voltage of the clutch control circuit.

4. The power-off protection device for a washing machine clutch according to claim 3, characterized in that: An isolation element is provided between the rectifier circuit and the switch circuit. The isolation element is a photoelectric coupler. A protection diode is connected in series to the input end of the photoelectric coupler.

5. The power-off protection device for the clutch of a washing machine according to claim 4, characterized in that: A level conversion circuit is arranged between the isolation element and the switching circuit, and the level conversion circuit includes a fourth switch, a power supply, and a voltage-dividing resistor. The first output end of the photoelectric coupler is connected to the power supply through a voltage-dividing resistor connected in series, and the second output end is grounded. The driving end of the fourth switch is connected between the voltage-dividing resistors, and the switch ends of the fourth switch are respectively connected to the power supply and the switching circuit.

6. The power-off protection device for a washing machine clutch according to claim 1, characterized in that: The switch circuit includes an RC filter circuit, a second switch, a third switch, a voltage-dividing resistor and a power supply; the voltage-dividing resistor is connected in series between the power supply and the ground; the driving end of the second switch is connected to the RC filter circuit, the switch ends of the second switch are respectively grounded and connected to the power supply through a voltage-dividing resistor; the driving end of the second switch is connected between the voltage-dividing resistors, and the switch ends of the second switch are respectively grounded and connected to the motor control module.

7. The power-off protection device for a washing machine clutch according to claim 6, characterized in that: The voltage of the clutch control circuit is connected to the RC filter circuit through a diode and to ground through a resistor.

8. The power-off protection device for a washing machine clutch according to any one of claims 1 to 7, characterized in that: The detection circuit is connected to both sides of the coil of the clutch, and the detection circuit outputs a control level signal to the controller.

9. A washing machine, characterized in that: The washing machine comprises the power-off protection device for the washing machine clutch according to any one of claims 1 to 8.

10. A control method for a washing machine according to claim 9, characterized in that: The method is: The controller does not output a power-on control signal to the clutch control circuit, the clutch control circuit is at a second voltage, and the power-on switch is disconnected; the detection circuit detects the second voltage of the clutch control circuit and outputs a first control level signal to the motor control module, and the motor control module controls the running state of the motor according to the control signal of the controller; The controller outputs a power-on control signal to the clutch control circuit, the clutch control circuit is a first voltage, and the power-on switch is turned on; the detection circuit outputs a first control level signal to the motor control module, and the motor control module controls the operating state of the motor according to the control signal of the controller; when the detection circuit outputs a second control level signal to the motor control module, the motor control module controls the motor to stop running.

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