This circuit for incandescent lamps was found in a 70s documentation. The circuit uses an SCR according to the power of the controlled lamps. The delay is a few seconds, given by capacitor C1.
This heartbeat sensor circuit was found in the July 1992 issue of Radio Electronics magazine. The...
We found this circuit in the 1982 SGS integrated circuit manual. The integrated circuit is not...
This TTL pulse stretcher or stretcher was found in a 90's EDN. The time constant R x C1 determines...