motor speed controller

This is an actual reverse engineered circuit diagram of the one transistor circuit most commonly used to drive Permanent Magnet DC motors in childrens’ toys. This type of circuit almost always uses the 625mW version of the ubiquitous 8050 or 8550 transistor. It is vital to note that there are two different varieties of each [...]

Reverse engineered circuit diagram of a PWM motor speed regulator out of an oral irrigator water pump. This circuit works quite well, keeping the speed of the small PM motor fairly constant regardless of load. No transistor heatsink is required since this is a switching regulator. The efficiency under high load would be a improved [...]

Reverse engineered circuit diagram of a motor speed regulator out of a line powered Cassette dictation machine containing a single heafty motor for all functions. This circuit works amazingly well, keeping the motor speed constant regardless of shaft load.
Unmarked didoe are silicon so use 1N4148. This circuit works just as well at only 12VDC. Resisror [...]