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.
The configuration presented below was obtained in the Linear Application Handbook of the National...
This circuit was found in December 1983 Radio Electronics magazine. The maximum output current is 1 A...
This untuned circuit uses one of the world's first commercial transistors, the CK722, having been...