This alarm circuit was found in the July 1992 Radio Electronics magazine. The circuit uses a small power stage for the speaker and has the sensitivity adjustment at R5.
Suggested by Burr Brown in 1969 documentation, this circuit makes use of an integrated component...
We found this circuit in the June 1988 Radio Electronics magazine. The power supply must be...
This circuit was obtained from a 2005 Linear Technology manual. The circuit is self-powered and can...