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 oscillator shown in the figure generates a 1 kHz tone that is reproduced on the speaker with...
In the figure we have the photo-conductive way of using a photocell to control a small motor with...
This circuit was found in the June 1991 issue of Radio Electronics magazine. The circuit uses two...