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.
Found in 1965 General Electric technical documentation, this half-wave circuit controls shunt type...
This circuit uses two relays that switch when the voltage exceeds the value given by zener D2. The...
This is one of many timer settings with the 555 found on this site. This is the traditional...