This latched alarm uses a double relay for this purpose and can control higher power external loads like a siren. The circuit is from 1974 documentation and has a very low consumption.
The operational amplifier used on this Raytheon circuit is similar to the 741. The circuit is from...
We found this circuit in the Radio Electronics magazine of November 1952. The circuit can be used...
This circuit has a traditional configuration explored in several other points of this site. The...