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. Approx circuit of DC-51 motor speed controller ...

This file type includes high resolution graphics and schematics when applicable. This 8051 microcontroller-based control circuit adjusts the speed of a small permanent-magnet dc motor via photosensors ...

With the help of this DC drill speed controller circuit you can control the number of revolutions of your drilling machine. A mini-drill machine is always needed in drilling the printed circuit board.

The motor-speed-control circuit in the figure shows an SG3524 pulse-width-modulation (PWM) IC, U2, driving the high side of a motor through a p-channel FET, Q1. The motor terminal voltage is more ...