Slave flash (CB8700E)

This circuit was found in a Popular Electronics from the 90s. It uses a LASCR which is a photo-SCR not common today.

Oscillator with AGC (CB6321E)
This circuit was found in a 1964 documentation. It shows how to achieve automatic gain control for...
Voltage to Frequency Converter with Potentiometer (CB25385E)
We found this circuit in the June 1991 issue of Radio Electronics magazine. The circuit can be...
Automatic recorder (CB8982E)
This circuit drives an old tape recorder when an audio signal is received. The circuit is...