In this project guide we’re building PWM Motor Speed Control circuit using two digital IC’s. We’ve published different types of PWM circuits, say from the basic PWM using NE 555 IC, to the much advanced PWM using micro controllers like AVR, 8051, and Arduino boards.
Here is a simple PWM motor speed controller circuit that can be used for varying the speed of low power DC motors . The variation in speed is achieved by varying the duty cycle of the pulse supplied to drive the motor. Of the two gates of IC CD40106B , N1 is wired as an inverting Schmitt Trigger astable multi vibrator for producing pulses and N2 as an inverting buffer to drive the transistor during positive cycles at base. The duty cycle is set from resistor R2. R1 limits the base current of transistor SL 100. The circuit is ideal for controlling toy motors,hand held mini fans , small blowers etc.
PWM Motor Speed Control Circuit Diagram with Parts List.
- By varying R2 duty cycle can be varied from 0% to 100%.
- For identifying pins of SL 100 ,the pin that is connected to casing is collector,the pin near to notch is emitter and the one remaining is base.
We have more Motor Control circuits that you may like to read, please take a look below: