Door buzzer or alarm (CB20492E)

This solar powered circuit was found in a 1991 documentation. The transistor is a general purpose NPN.

Stereo preamplifier (CB20654E)
We found this circuit in a Hands-on Electronics from 1985. The circuit is based on common...
ON Semiconductor AMIS−3910XGEVB Evaluation Board
ON Semiconductor AMIS−3910XGEVB Evaluation Board demonstrates the features and capabilities of the...
Progressive Switch (CB16940E)
When S1 is closed, the L1 lamp turns on and the L2 lamp turns off. The circuit is powered...