This interesting multi-channel circuit was found in the August 1988 issue of Radio Electronics magazine. It monitors the signal from 4 sound channels simultaneously.
We found this circuit in Popular Electronics from 1992. The circuit uses general purpose...
This approach alarm circuit was found in the September 1970 Radio Electronics issue. The 1 mH coil...
This circuit can function as both a light alarm and a shadow alarm. The components are common. The...