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 provides two outputs of the same signal. One with the original phase and the other...
S1 changes the selection of the input signals in the circuit shown here. Other type of circuits,...
We found this relaxation circuit with diac in an opto-electronic documentation with diac....