The circuit in the figure provides three levels of speed control for a dc motor, using a PC’s parallel port (LPT1). A C++ program performs the control functions by allowing the signals from the ...

This microcontroller-based control circuit adjusts the speed of a small permanent-magnet DC motor to one of four speeds as selected by a pair of photosensors.

En route to getting the off-the-peg DC-51 motor speed controller to better suit my small milling machine, I had a go at working out what the circuit is.

Traditionally, DC motors have been used in precise speed control applications because of their ability to provide acceleration and deceleration from a dead stop position to full speed fairly easily.

Controlling a small dc motor without speed control sounds like a trivial task; a switch or a relay should suffice. However, several problems accompany this approach. For one, the switch, because of ...

Learning Outcomes Understand how to specify the proper AC or DC motor for a machine design. Integrate the motor to a machine, based on analysis of motor equations for voltage, current, torque and ...

A motor drive controls the speed, torque, direction, and resulting horsepower of a motor. Dc drives typically control a shunt-wound dc motor, which has separate armature and field circuits.

Speed control: There are two ways to adjust the speed of a wound-field dc motor. Combinations of the two are sometimes used. Shunt-field control: Reel drives require this kind of control.