This car alarm was obtained in a Signetics documentation from the 1980s. The circuit uses the 555 and has a pulsed output to activate a relay that controls the horn. The sensors are parallel connected.
In a reflex receiver, the detected audio signal is applied back to the circuit input to receive new...
This circuit was found in the February 1991 Radio Electronics magazine. The circuit must be...
This circuit was obtained in an Electronic Design from the 80's. It has the adjustment of the gain...