Motor driving circuit of washing machine

Abstract

The utility model discloses a motor drive circuit of a washing machine, which comprises a power supply VCC, a drive control circuit and a motor, the drive control circuit is electrically connected with the power supply VCC and the motor, the motor is electrically connected with an overheat water inlet protection circuit, and the overheat water inlet protection circuit is also electrically connected with the drive control circuit; the motor comprises a motor M1 and a motor M2; the overheating water inlet protection circuit comprises a temperature detection circuit, a water inlet detection circuit and a control chip MCU. The driving control circuit comprises a one-way switch KT1 and a standard switch KT2, and one end of the one-way switch KT1 is electrically connected with a pin 1 of the standard switch KT2. According to the utility model, through the arrangement of the overheating water inlet protection circuit, when the motor M1 and the motor M2 are overheated or water enters the motor M1 and the motor M2, the control switch K1 can be timely controlled to be switched off, so that the timely power-off effect is achieved, the burnout or electric shock risk of the motor M1 and the motor M2 can be effectively reduced, and the use safety is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of motor drive circuits, in particular to a motor drive circuit for a washing machine. Background Technique

[0002] With the improvement of people's living standards, washing machines have become indispensable household appliances. The driving of washing machines is controlled by motors. Among them, the motor drive circuit is a circuit used to control the motors of washing machines. The motor drive circuits in the prior art will generate a large amount of heat after long-term use. When the motor is hot, it cannot cut off the power in time for protection. The motor is in an overheated state for a long time and is easily burned out. In addition, when water enters the motor, the power cannot be cut off in time, thus there is a risk of electric shock. Considering the above situations, we have proposed a motor drive circuit for a washing machine. Content of the Utility Model

[0003] The purpose of the utility model is to solve the deficiencies existing in the prior art and propose a motor drive circuit for a washing machine.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A motor drive circuit for a washing machine includes a power supply VCC, a drive control circuit and a motor. The drive control circuit is electrically connected to the power supply VCC and the motor. The motor is electrically connected to an overheat and water inlet protection circuit, and the overheat and water inlet protection circuit is also electrically connected to the drive control circuit;

[0006] The motor includes a motor M1 and a motor M2;

[0007] The overheat and water inlet protection circuit includes a temperature detection circuit, a water inlet detection circuit and a control chip MCU;

[0008] The drive control circuit includes a unidirectional switch KT1 and a standard switch KT2. One end of the unidirectional switch KT1 is electrically connected to pin 1 of the standard switch KT2. One end of pin 1 of the standard switch KT2 and one end of the unidirectional switch KT1 are also electrically connected to one end of a control switch K1. The other end of the control switch K1 is electrically connected to one end of a resistor R1. The other end of the resistor R1 is electrically connected to the power supply VCC. Pin 5 and pin 6 of the standard switch KT2 are electrically connected to the same capacitor C1. The capacitor C1 is connected in parallel with pins 1 and 2 of the motor M1. Pin 6 of the standard switch KT2 is also electrically connected to one end of a resistor R2. The other end of the resistor R2 is electrically connected to pin 3 of the standard switch KT2. One end of the capacitor C1 is also electrically connected to one end of the resistor R2. The other end of the unidirectional switch KT1 is electrically connected to one end of a capacitor C2. The other end of the capacitor C2 is electrically connected to pin 1 of the motor M2. Pin 3 of the motor M2 is electrically connected to one end of a capacitor C3. The other end of the capacitor C3 is electrically connected to pin 2 of the motor M2. One end of the control switch K1 is electrically connected to pin 6 of the control chip MCU.

[0009] Preferably, the temperature detection circuit includes a thermistor NTC. One end of the thermistor NTC is electrically connected to pin 3 of the motor M1 and pin 2 of the motor M2. The other end of the thermistor NTC is electrically connected to one end of a resistor R3 and the base of a triode Q1. The base of the triode Q1 is electrically connected to one end of a capacitor C4. The emitter of the triode Q1 is electrically connected to one end of a resistor R5. The other end of the resistor R5, the other end of the capacitor C4, the other end of the resistor R3, and the emitter of the triode Q1 are all grounded. The collector of the triode Q1 is electrically connected to one end of a resistor R11. The other end of the resistor R11 is electrically connected to pin 5 of the control chip MCU.

[0010] Preferably, the water inlet detection circuit includes a triode Q2. The base of the triode Q2 is electrically connected to an M wire terminal. The collector of the triode Q2 is electrically connected to one end of a resistor R9. The other end of the resistor R9 is electrically connected to pins 1 and 3 of a resistor R7. Pin 2 of the resistor R7 is electrically connected to an N wire terminal. Both the M wire terminal and the N wire terminal are electrically connected to pin 3 of a motor M1 and pin 2 of a motor M2. Pin 3 of the resistor R7 is electrically connected to one end of a resistor R6. The other end of the resistor R6 is electrically connected to one end of a capacitor C5. The other end of the capacitor C5 is electrically connected to the negative electrodes of a diode D2, a diode D3, a diode D5, and one end of a resistor R10. The positive electrode of the diode D2 is electrically connected to the negative electrode of a diode D1. The positive electrode of the diode D1 is electrically connected to one end of a resistor R8. The other end of the resistor R8 is electrically connected to the other end of the resistor R9. The positive electrode of the diode D3 is electrically connected to the negative electrode of a diode D4. The positive electrode of the diode D4 is electrically connected to the emitter of the triode Q2. The other end of the resistor R10 is electrically connected to the emitter of the triode Q2. The positive electrode of the diode D5 is electrically connected to pin 2 of a control chip MCU. The negative electrode of the diode D5 is electrically connected to one end of a resistor R12. The other end of the resistor R12 is electrically connected to pin 3 of the motor M1 and pin 2 of the motor M2.

[0011] Preferably, pin 3 of the control chip MCU is grounded, and pin 7 of the control chip MCU is electrically connected to a supply voltage VCC.

[0012] Preferably, the capacitor C4 is a small-capacity aluminum electrolytic capacitor, and the triode Q1 is a Darlington transistor with a model number of 2N4401.

[0013] Preferably, the triode Q2 is a thyristor with a model number of kp100-3.

[0014] Compared with the existing technology, the beneficial effects of the present utility model are as follows:

[0015] By providing the overheat and water inlet protection circuit, the present utility model can timely control the control switch K1 to disconnect when the motors M1 and M2 are overheated or water enters, achieving the effect of timely power-off, effectively reducing the risk of burning out or electric shock of the motors M1 and M2, and improving the use safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a connection block diagram of a motor drive circuit of a washing machine proposed by the present utility model;

[0017] Figure 2 is a circuit diagram of a motor drive circuit of a washing machine proposed by the present utility model;

[0018] Figure 3The circuit diagram of the overheat and water inlet protection circuit for the motor drive circuit of a washing machine proposed by the present utility model. Detailed implementation manners

[0019] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments.

[0020] Refer to Figures 1 - 3 , a motor drive circuit of a washing machine, including a power supply VCC, a drive control circuit and a motor. The drive control circuit is electrically connected to the power supply VCC and the motor. The motor is electrically connected to an overheat and water inlet protection circuit, and the overheat and water inlet protection circuit is also electrically connected to the drive control circuit;

[0021] The motor includes a motor M1 and a motor M2, and both the motor M1 and the motor M2 are installed inside the washing machine;

[0022] The overheat and water inlet protection circuit includes a temperature detection circuit, a water inlet detection circuit and a control chip MCU. Among them, the pin 3 of the control chip MCU is grounded, and the pin 7 of the control chip MCU is electrically connected to a supply voltage VCC;

[0023] Among them, the temperature detection circuit includes a thermistor NTC. One end of the thermistor NTC is electrically connected to the pin 3 of the motor M1 and the pin 2 of the motor M2. The thermistor NTC is used to detect the heat of the motor M1 and the motor M2. The other end of the thermistor NTC is electrically connected to one end of a resistor R3 and the base of a triode Q1. One end of a capacitor C4 is electrically connected to the base of the triode Q1. The emitter of the triode Q1 is electrically connected to one end of a resistor R5. The other end of the resistor R5, the other end of the capacitor C4, the other end of the resistor R3 and the emitter of the triode Q1 are all grounded. The collector of the triode Q1 is electrically connected to one end of a resistor R11. The other end of the resistor R11 is electrically connected to the pin 5 of the control chip MCU. Among them, the capacitor C4 is a small-capacity aluminum electrolytic capacitor, which can prevent the influence of external interference on the circuit. The triode Q1 is a Darlington tube, and its model is 2N4401, which can amplify the input current to a large enough current to drive the output load;

[0024] The water inlet detection circuit includes a triode Q2, where the triode Q2 is a thyristor with the model kp100-3. The base of the triode Q2 is electrically connected to the M wire terminal. The collector of the triode Q2 is electrically connected to one end of a resistor R9. The other end of the resistor R9 is electrically connected to pins 1 and 3 of a resistor R7. Pin 2 of the resistor R7 is electrically connected to the N wire terminal. Both the M wire terminal and the N wire terminal are electrically connected to pin 3 of the motor M1 and pin 2 of the motor M2. Pin 3 of the resistor R7 is electrically connected to one end of a resistor R6. The other end of the resistor R6 is electrically connected to one end of a capacitor C5. The other end of the capacitor C5 is electrically connected to the negative electrodes of a diode D2, a diode D3, a diode D5, and one end of a resistor R10. The positive electrode of the diode D2 is electrically connected to the negative electrode of a diode D1. The positive electrode of the diode D1 is electrically connected to one end of a resistor R8. The other end of the resistor R8 is electrically connected to the other end of the resistor R9. The positive electrode of the diode D3 is electrically connected to the negative electrode of a diode D4. The positive electrode of the diode D4 is electrically connected to the emitter of the triode Q2. The other end of the resistor R10 is electrically connected to the emitter of the triode Q2. The positive electrode of the diode D5 is electrically connected to pin 2 of the control chip MCU. The negative electrode of the diode D5 is electrically connected to one end of a resistor R12. The other end of the resistor R12 is electrically connected to pin 3 of the motor M1 and pin 2 of the motor M2;

[0025] The drive control circuit includes a one-way switch KT1 and a standard switch KT2. One end of the one-way switch KT1 is electrically connected to pin 1 of the standard switch KT2. Pin 1 of the standard switch KT2 and one end of the one-way switch KT1 are also electrically connected to one end of the same control switch K1. The other end of the control switch K1 is electrically connected to one end of a resistor R1. The other end of the resistor R1 is electrically connected to the power supply VCC. Pins 5 and 6 of the standard switch KT2 are electrically connected to the same capacitor C1. The capacitor C1 is connected in parallel with pins 1 and 2 of the motor M1. Pin 6 of the standard switch KT2 is also electrically connected to one end of a resistor R2. The other end of the resistor R2 is electrically connected to pin 3 of the standard switch KT2. One end of the capacitor C1 is also electrically connected to one end of the resistor R2. The other end of the one-way switch KT1 is electrically connected to one end of a capacitor C2. The other end of the capacitor C2 is electrically connected to pin 1 of the motor M2. Pin 3 of the motor M2 is electrically connected to one end of a capacitor C3. The other end of the capacitor C3 is electrically connected to pin 2 of the motor M2. One end of the control switch K1 is electrically connected to pin 6 of the control chip MCU; Through the overheat and water inlet protection circuit provided by the present utility model, when the motors M1 and M2 are overheated or water enters, the control switch K1 can be timely controlled to disconnect, achieving the effect of timely power-off, effectively reducing the risk of the motors M1 and M2 being burned out or getting an electric shock, and improving the use safety.

[0026] Working principle: When in use, it is powered by the power supply VCC. The motor M1 and the motor M2 are controlled through the one-way switch KT1 and the standard switch KT2 respectively, and the on / off of the entire drive control circuit is controlled through the control switch K1. During the operation of the motor M1 and the motor M2, the heat of the motor M1 and the motor M2 is detected by the thermistor NTC, and the electrical signal is transmitted to the resistor R3 and the triode Q1. When the output heat signal is at the normal threshold value, the triode Q1 is not turned on, so it will not send a signal to the control chip MCU, and then the control switch K1 is in the suction and energized state. When the output heat signal exceeds the threshold value, the triode Q1 is turned on, sends a signal to the control chip MCU, and the control chip MCU controls the control switch K1 to disconnect, then the power supply voltage of the entire drive circuit is disconnected, so that the motor M1 and the motor M2 stop working. When the motor M1 and the motor M2 are overheated, the method of timely power-off can effectively reduce the risk of the motor M1 and the motor M2 being burned out due to overheating;

[0027] During the operation of the motor M1 and the motor M2, the internal conditions of the motor M1 and the motor M2 are detected through the M wire end and the N wire end. When water enters the motor M1 and the motor M2, at this time, the M wire end and the N wire end are short-circuited by water, and its voltage signal will conduct the triode Q2 through the resistor R12, the diode D5, and the resistor R10. At the same time, the diode D5 sends a signal to the control chip MCU, and the control chip MCU controls the control switch K1 to disconnect, then the power supply voltage of the entire drive circuit is disconnected, and the motor M1 and the motor M2 stop working. In the case of no water ingress, the voltage signal enters through the M wire end and the N wire end, and the triode Q2 is in the non-conducting state, and thus will not send a signal to the control chip MCU, making the control switch K1 in the energized state. By the method of timely power-off when water enters the motor M1 and the motor M2, the risk of electric shock can be effectively reduced and the use stability can be improved.

[0028] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A motor drive circuit for a washing machine, comprising a power supply VCC, a drive control circuit and a motor, characterized in that: The drive control circuit is electrically connected to the power supply VCC and the motor, the motor is electrically connected to the overheat water inlet protection circuit, and the overheat water inlet protection circuit is also electrically connected to the drive control circuit; The motor includes a motor M1 and a motor M2; The overheat water inlet protection circuit comprises a temperature detection circuit, a water inlet detection circuit and a control chip MCU; The drive control circuit includes a unidirectional switch KT1 and a standard switch KT2, one end of the unidirectional switch KT1 is electrically connected to pin 1 of the standard switch KT2, pin 1 of the standard switch KT2 and one end of the unidirectional switch KT1 are also electrically connected to one end of the same control switch K1, the other end of the control switch K1 is electrically connected to one end of a resistor R1, the other end of the resistor R1 is electrically connected to a power supply VCC, pins 5 and 6 of the standard switch KT2 are electrically connected to the same capacitor C1, and the capacitor C1 is connected in parallel to pins 1 and 2 of the motor M1, Pin 6 of the standard switch KT2 is also electrically connected to one end of the resistor R2, the other end of the resistor R2 is electrically connected to pin 3 of the standard switch KT2, one end of the capacitor C1 is also electrically connected to one end of the resistor R2, the other end of the unidirectional switch KT1 is electrically connected to one end of the capacitor C2, the other end of the capacitor C2 is electrically connected to pin 1 of the motor M2, pin 3 of the motor M2 is electrically connected to one end of the capacitor C3, the other end of the capacitor C3 is electrically connected to pin 2 of the motor M2, and one end of the control switch K1 is electrically connected to pin 6 of the control chip MCU.

2. A motor drive circuit for a washing machine according to claim 1, characterized in that: The temperature detection circuit includes a thermistor NTC, one end of the thermistor NTC is electrically connected to pin 3 of motor M1 and pin 2 of motor M2, the other end of the thermistor NTC is electrically connected to one end of resistor R3 and the base of transistor Q1, the base of transistor Q1 is electrically connected to one end of capacitor C4, the emitter of transistor Q1 is electrically connected to one end of resistor R5, the other end of resistor R5, the other end of capacitor C4, the other end of resistor R3 and the emitter of transistor Q1 are all grounded, the collector of transistor Q1 is electrically connected to one end of resistor R11, and the other end of resistor R11 is electrically connected to pin 5 of control chip MCU.

3. A motor driving circuit for a washing machine according to claim 1, characterized in that: The water inlet detection circuit includes a transistor Q2, the base of the transistor Q2 is electrically connected to the M wire end, the collector of the transistor Q2 is electrically connected to one end of a resistor R9, the other end of the resistor R9 is electrically connected to pins 1 and 3 of a resistor R7, pin 2 of the resistor R7 is electrically connected to the N wire end, the M wire end and the N wire end are both electrically connected to pin 3 of a motor M1 and pin 2 of a motor M2, pin 3 of the resistor R7 is electrically connected to one end of a resistor R6, the other end of the resistor R6 is electrically connected to one end of a capacitor C5, and the other end of the capacitor C5 is electrically connected to the cathode of a diode D2, the cathode of a diode D3, the cathode of a diode D5 and the resistor R The anode of the diode D2 is electrically connected to the cathode of the diode D1, the anode of the diode D1 is electrically connected to one end of the resistor R8, the other end of the resistor R8 is electrically connected to the other end of the resistor R9, the anode of the diode D3 is electrically connected to the cathode of the diode D4, the anode of the diode D4 is electrically connected to the emitter of the transistor Q2, the other end of the resistor R10 is electrically connected to the emitter of the transistor Q2, the anode of the diode D5 is electrically connected to the pin 2 of the control chip MCU, the cathode of the diode D5 is electrically connected to one end of the resistor R12, and the other end of the resistor R12 is electrically connected to the pin 3 of the motor M1 and the pin 2 of the motor M2.

4. A motor drive circuit for a washing machine according to claim 1, characterized in that: The pin 3 of the control chip MCU is grounded, and the pin 7 of the control chip MCU is electrically connected to the power supply voltage VCC.

5. The motor driving circuit of a washing machine according to claim 2, characterized in that: The capacitor C4 is a small-capacity aluminum electrolytic capacitor, and the transistor Q1 is a Darlington transistor, whose model is 2N4401.

6. A motor driving circuit for a washing machine according to claim 3, characterized in that: The transistor Q2 is a thyristor, and its model is kp100-3.

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