This circuit was found in a 1968 documentation. It makes use of both NO and NC reed-switches and small magnets attached to a card in the form that results in the drive combination.
Other series amplifiers such as the MC3301, MC3401 and LM2900 can be used on this circuit. We...
This power control for powers up to about 10 W uses wire potentiometers in an arrangement that...
This configuration is from Texas Instruments technical documentation. In it we have the way to use...