When the phone rings, a high-powered incandescent light comes on. This circuit can be interesting to obtain the remote call warning or to assist the hearing impaired.
This circuit is from a Radio Electronics from April 1965. It uses an incandescent lamp, and the...
This circuit was found in a 1968’s publication and uses germanium transistors. The characteristic...
This is a single IC voltage regulator that can acts in the range from 1.2 to 20 V. Output currewnt is up to...