This simple sensitive circuit was suggested in a July 1992 Radio Electronics issue. The relay is a double-contact changeover relay. Sensitivity adjustment is made at R2.
This circuit was found in a General Electric documentation from 1965. The circuit is full wave for...
We found this circuit in the Texas Instruments' Linear Circuits Applications. It uses an...
In the presented circuit it is possible to vary the frequency of the rectangular signal produced. This...