This circuit is for a siren that can be used with any of the above alarms and also other types. The circuit is from a Radio Electronics magazine from May 1975.
This simple circuit causes an LED to flash at times whose active cycle is determined by C1 and C2....
In the figure we show the typical configuration of a shared line using a twisted pair where the...
This circuit appeared in Amateur Radio Today in an issue and was found in a 1995 issue. The...