We found this circuit in the Encyclopedia of Electronic Circuits Volume 5 from 1995. It uses a 3-terminal transducer from the time. The circuit is triggered by light.
This circuit was obtained in an Electronics Now of the 90s. The circuit monitors the DIN connector of...
Found in a 1965 Motorola documentation, this circuit uses a neon lamp as a trigger element. The SCR...
The outputs of each switch position are determined by the zener voltage plus the drive voltage of each...