Washing machine motor controller circuit

Washing machines have always been an important part of our daily lives. However, the problems we have to deal with within a few months of using them make it more difficult. Previously, we have published an automatic washing machine control circuit. This is because most washing machines have a single-phase motor integrated in their system and the timing and direction of the motor are controlled by an external mechanical switch which is prone to wear and tear and on the other hand is not economical. Moreover, the project “Washing Machine Motor Controller Circuit” corrects the flaws in the traditional washing machine system with a single-phase motor.

Washing Machine Motor Controller Circuit Description

The overall picture of the project is depicted in Figure 1. The single phase motor works with the main timer and the rotation direction controller to calculate the wash time, i.e. the period of time that the motor should rotate, stop the movement of the motor after every 10 seconds, at intervals of
3 seconds, and reverse the rotation direction of the motor.

Figure 2
shows a clear and detailed method of controlling the rotation of the motor in the desired direction. As shown in Figure 2 (a), to make the motor rotate clockwise, the switch SW1 should be in position A, then the DC current flows through the coil L1 of the motor, and due to the capacitor C, the phase-shifted current flows through the coil L2 of the motor. When the switch is switched to position
B, vice versa, so the motor rotates in the counterclockwise direction, as shown in Figure 2 (b).

Though we can use a switch to change the direction of the motor's rotation, this cannot be done in a split second. It is better to wait for some time before changing the direction of the motor to avoid any possible damage to the circuit. Therefore, we have included
IC2 (IC 555) to monitor the spin duration of the motor, which provides on and off time pulses of "10" seconds and "3" seconds alternately on its output pin. This causes the washing machine to
automatically stop after every 3 seconds of rotation in either direction for 10 seconds. The resistors R3 and R4 have been adjusted accordingly for the project.

Main Timing Section | Washing Machine Motor Controller Circuit

For the main timer section required for single phase motor, IC1 (IC 555) is used and using 1
megohm potentiometer, we can set the time for which the motor should rotate. To avoid the on time, when the potentiometer knob is in zero position, a 47 kΩ resistor is placed in series next to the potentiometer.

The outputs of the two ICs; IC1 and IC2 should be used in combination to stop the rotation of the motor set by the main timer which is 18
minutes for the component values ​​given in the project. For this purpose, a NAND gate N1 (IC3) is integrated in the circuit. The outputs obtained from the two ICs; IC1 and IC2 are given as inputs to the gate which
gives a low output only when it receives a high input from both the ICs. Relay RL1 is connected to the end of the NAND gate pin 3 through a PNP transistor T1. The low output of the NAND gate powers the relay. The power line 220V passes through the relay
RL1 and soon after the completion of 10 seconds, the display turns off for 3 seconds. The timing diagram of this project is shown in Figure 3.

When IC2 is in the “on” time, relay RL2 is energized by
the low output provided by the negative edge triggered JK flip-flop fixed at IC2 pin 2, and then the washing machine motor starts rotating in a specific direction. Also, during the off time of IC2, the gate of N1 provides a high output, which de-energizes relay RL1, and then interrupts
the main power flow to RL2, and the monitor stops rotating.

Another resistor R8 holds pin 2 high and prevents a floating fault at trigger pin 2 of IC1.

Washing Machine Motor Controller Circuit Parts List

Resistors (all 1/4 Watt, ± 5% carbon)

R1= 47 KΩ

R2、R7= 470 Ω

R3= 1 MΩ

R4= 470 KΩ

R5、R6= 100 Ω

R8= 100 KΩ

VR1 = 1 MΩ potentiometer.

Capacitors

C1 = 1000 μF/16V (electrolytic capacitor)

C2, C4 = 0.01 μF (ceramic disc)

C3 = 10 μF/16V (electrolytic capacitor)

semiconductor

IC 1 IC 2 = NE555 (Single Precision Timer IC)

IC3 = CD4011 (CMOS Quad 2-input NAND Gate)

Integrated Circuit 4 = CD4027 (CMOS Dual J-K Master-Slave Trigger)

T1, T2 = SK100 (general purpose, medium power PNP transistor)

D1, D2 = 1N4007 (general purpose rectifier diode)

Miscellaneous

RL series 1, RL2 = 6V, 100Ω 1C/O relay

Southwest 2 = One-touch switch