For experiments with a disk rotating at various speeds, the April 1998 Electronics Now magazine suggests this PWM motor control. The current with the LM317 is 1.5A maximum.
This circuit was found in a 1980s US publication. There may be some difficulty in obtaining the...
The circuit shown is from the Motorola Linear Databook of 1990. In the example, the components are for the...
Ideal for benchtop use, this dual-band circuit was obtained from the 1995 Electronics Now...