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.
Recommended for automotive use, this circuit is used to indicate the activation of functions. The...
This very high input impedance preamplifier is from a publication of 1977 but can also be mounted...
This circuit was found in a Popular Electronics of the 90s. The resistor R4 determines the load...