With the configuration shown in the figure, we have the relay being activated when the microphone picks up a sound and shutdown when the X1 reset sensor is activated.
We found this circuit in a 2005 documentation. The circuit uses an infrared piezo sensor...
This circuit was found in a 1995 documentation. It deactivates a power supply in the event of a...
This circuit was found in the September 1993 Electronics Now magazine. It is based on the 555 and...