Using a power supply adaptor with a speed regulator like the one featured here can certainly improve the performance of the drill. Schematic of the Mini Drill Speed Control Circuit. The speed ...

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. Resources. Directory.

Approx circuit of DC-51 motor speed controller (D6 and D8 are the wrong way around, and there may be more errors). And the more I looked at the circuit, the more I liked the speed controller. Update ...

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 ...