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.
This circuit triggers a relay when the phone rings. An application is like remote doorbell. The circuit...
This simple CMOS circuit generates two-frequency signals for use as a signal injector. The circuit...
With a mains-rated transformer and 1:1 winding this benchtop circuit was found in the January 1995...