Found in American documentation from the 1980s, this circuit prolongs the ringing of a doorbell or chime powered by a 6 V continuous voltage. The transistor can be a BD136.
This 0.5 Hz filter was found in the December 1990 issue of Radio Electronics magazine. The power...
This circuit was obtained in the SGS manual of linear integrated circuits of 1982. The maximum...
This circuit allows linear brightness control of an LED from an input voltage. The power supply must...