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.
This simple circuit with SCR and unijunction transistor appeared in Radio Electronics magazine in July...
With this circuit, using a single control voltage, you can increase the brightness of the lamp...
This 18 V x 300 mA power supply was found in a 1969 documentation. The integrated circuit is...