Motor Control


PWM Modulator

If you ever thought of experimenting with pulse-width modulation, this circuit should get you started nicely. We’ve kept simplicity in mind and used a dual 555 timer, making the circuit a piece of cake. We have even designed a small PCB for this, so building it shouldn’t be a problem at all. This certainly isn’t […]



Drill Speed Regulator

A mini-drill machine is always needed in drilling the printed circuit board. It is usually powered by batteries that limit the drill’s capacity.Using a power supply adaptor with a speed regulator like the one featured here can certainly improve the performance of the drill. The speed regulator can maintain the speed of the drill no […]


High Current Op-Amp for Motor Driver

The OPA2544 is a dual high-voltage/high-current operational amplifier. We can use it for driving a wide variety of high power loads. 2A output current is provided by this device and power supply range extends to +-35V. Two high performance FET op amps with high power output stages are integrated in OPA2544 on a single monolithic […]


Fan Speed Controller Using Op-Amp

We can make an enhancement to DAC drive fan controllers with the use of an external amplifier that closes the loop around the tachometer. Essentially linear control over the full range of 8 bit DAC codes from 0 to 255 is provided by this enhancement. This only requires a little signal conditioning and a suitable […]


F/V Converter in CLosed Loop Motor Speed Control System

Closed loop or servo system has the ability to stabilize the controlled plant at a specified operating condition. The plant, the controlled sub-system, can be any form of controllable system. In motor control system, the plant is off course a motor. The basic principle of automatic control mechanism in motor control is by monitoring the […]


DC Fan Controller

This circuit is ideal to control the cooling fan of heat generated electronic gadgets like power amplifiers. The circuit switches on a fan if it senses a temperature above the set level. The fan automatically turns off when the temperature returns to normal. The circuit uses an NTC (Negative Temperature Coefficient) Thermister to sense heat. […]


Rotative Speed Regulator Borer, Driller Controller

This rotative speed regulator circuit schematic allows to control the holing speed of your borer or driller machine. This project is based on the fact that if the load grows, the voltage decrease and current increase. Use this circuit to control the speed of revolutions of your drilling mill or bench drill. Driller controller circuit […]


PWM Motor Speed Control Using Class D Audio Amplifier

This is class D audio amplifier circuit that is used to control PWM motor speed. This circuit has two advantages for battery-powered portable devices. First, this circuit produces much less power dissipation than do it’s linear cousins. Second, it enhances battery life. Here is the circuit: A potentiometer (R2) is used to generate a variable […]


Motor-Speed Control Employs Class-D Power Amplifier

A dual benefit for battery-powered portable devices is provided by Class D audio amplifier. The produce much less power dissipation than do their linear cousins and they enhance battery life. Those features make this device an ideal candidate for controlling speed and direction in small electric motors. The standard application circuit for a class D […]