This 1968 Mullard circuit detects fire by smoke using LDR-type sensors. The circuit makes use of transistors of the time that admit equivalents.
This circuit was found in a 1964 documentation. It shows how to achieve automatic gain control for...
We found this circuit in the June 1991 issue of Radio Electronics magazine. The circuit can be...
This circuit drives an old tape recorder when an audio signal is received. The circuit is...