Pulse Width Modulation DC Motor Control Circuit
Description Often, people attempt to control DC motors with a variable resistor or variable resistor connected to a transistor. While the latter approach works well, it generates heat and hence wastes power. This simple pulse width modulation DC motor control eliminates these problems. It controls the motor speed by driving the motor with short pulses. These pulses vary in duration to change the speed of the motor. The longer the pulses, the faster the motor turns, and vice versa. Circuit Diagram Parts R1 1 Meg 1/4W Resistor R2 100K Pot C1 0.1uF 25V Ceramic Disc Capacitor C2 0.01uF 25V Ceramic Disc Capacitor Q1 IRF511 MOSFET or IRF620 U1 4011 CMOS NAND Gate S1 DPDT Switch M1 Motor (See Notes) MISC Case, Board, Heatsink, Knob For R2, Socket For U1 Notes R2 adjusts the speed of the oscillator and therefore the speed of M1. M1 can be any DC motor that operates from 6V and does not draw more than the maximum current of Q1. The voltage can be increased by connecting the higher v...