Various motor control circuit is already available in internet and this is also not new idea for the electronics hobbyist. The circuit of published here is different from other circuit available for motor control because it let you run a DC motor in clock wise or anti clock wise direction and stop it using a single switch. DC motor control circuit has also another advantage i.e. for proper operation of the motor this circuit provide constant voltage. Here we use three LEDs LED
1 through LED3 for indicates that the motor is in stop, forward rotation and reverse rotation respectively.
Circuit Description of DC Motor Control Circuit
The circuit of DC motor control circuit published here utilize three timer IC (IC1, IC3 and IC4) and a decade counter IC2 (CD4017). When we press switch SW1 a false trigger is given to pin 2 of IC1 and output is available. To avoid this false triggering IC1 is used here as monostablemultivibrator (timer circuit) for approximately 500 millisecond (ms).
Initially, the circuit DC motor controller is in reset condition with output at pin 3 of IC2 being high. Since output at pin 2 and 7 of IC2 is low, the output of IC3 and IC4 are high and motor does not rotate. This condition or stop condition of motor is indicated by glowing LED1.
When we again press the switch SW1, IC1 provide a clock pulse at pin 14 of IC2 which further advances its output by one and its high state shifts from pin 3 to pin 2. When pin 2 goes high, the output at pin 3 of IC3 goes low due to high trigger. The high output at pin 3 of IC4 rotate motor in clockwise direction. This state or forward state of motor is indicated by glowing LED2.