This circuit uses a transistor to trigger the alarm from a low quiescent current sensor. The relay is 12 V. The circuit is from Radio Electronics magazine, April 1975.
This circuit was obtained from an American documentation from the 60s. The circuit makes use of...
This circuit was obtained from an English publication from the 70's. The circuit is still current for...
When a voice signal enters this circuit, the volume of the music being played automatically...