Dc Motor Speed Control Circuit

The ic then increases the motor voltage so that the original speed is recovered.

Dc motor speed control circuit. A circuit which enables a user to linearly control the speed of a connected motor by rotating an attached potentiometer is called a motor speed controller circuit. In addition to controlling the motors speed its direction of rotation can be also changed using this circuit. Dc motor is a purely inductive load so if you want to control the speed of the dc motor then we have to upper lower the voltage for higher lower speeds. This variable resistor is called as a diverter as the desired amount of current can be diverted through this.

Are you fed up with ordinary pwm circuits which do not provide perfect dc motor speed control especially at lower speeds. Many dc motor speed control circuits have been published here but this is the first one using ne555 timer ic. Before discussing the speed control of dc motor let us first establish the expression of the speed of a dc motor the voltage equation of a dc motor is where e b is the back emf v is the supply voltage i a the armature current and r a is the armature resistance. The speed is controlled through an externally applied varying dc voltage source.

Again the expression of back emf in a dc motor is where φ is the field magnetic flux n is rpm of the motor z is the number of. The circuit comprises a timer ne555 ic1 medium power motor driver transistor bd239 t1 high power switching transistor bd249 t2 and a few other discrete components. Speed control of series motor 1. A variable resistance is connected parallel to the series field as shown in fig a.

Hence very smooth speed control of the dc motor can be obtained by this method. 3 easy to build speed controller circuits for dc motors are presented here one using mosfet irf540 second using ic 555 and the third concept with ic 556 featuring torque processing. This motor speed controller uses a single ic lm1014 to control the speed of a dc motor. It senses the increase in the motor current when the rotation of the motor slows down due to a load.

The method of pwm is explained here. Consider a simple circuit as shown in figure below. But in practically higher voltage and lower voltage is not that type of possible so in this case we use another type of method which is called pwm better known as pulse width modulation. The dc motor speed control circuit is primarily a 555 ic based pwm pulse width modulation circuit developed to get variable voltage over constant voltage.

Here is a simple dc electric motor variable speed controller circuit that can be configured to control the sweep rate of automobiles windscreen wipers.