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.
Although it is a common configuration today, this circuit was taken from an old publication. The...
This configuration was found in an English magazine from 1965. It is valid for any junction FET. The...
The circuit in the figure is an amplifier with gain 10 for alternating signals using the 741. The...