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 fact, the original American publication exaggerated a little about the range that a good...
We found this circuit in an American documentation from the 90s. Through an LED it indicates the...
August 2017 - Mouser Electronics is announcing the availability of TDK ICS-52000 microphones with...