This simple latching alarm circuit using CMOS gates was found in the May 1990 Radio Electronics magazine. The supply voltage is dependent on the relay.
The circuit presented was obtained in the 1994 Linear Applications Handbook by National...
We found this circuit in Motorola's 1993 Linear Interface ICs. The power supply does not have to...
I found this circuit in an English magazine from July 1982. The circuit is still viable by using...