This circuit takes advantage of the hysteresis of a relay to provide a latching effect. The circuit acts as a trigger and the components must be according to the used relay.
This simple trigger circuit was found in a 90’s American documentation. The integrated circuit is...
This sensitive circuit was found in the August 1971 issue of Radio Electronics magazine. The SCR...
The varactor or varicap diode tunes the signal for listening to SSB signals on a common receiver. The...