This signal injector and tracer (follower) was found in an old American documentation. The transistors can be general use and power is made with one or two common cells.
This circuit was found in an old publication about transistor. The original trasistors are...
This circuit keeps a flashing LED when a balcony lamp, for example, is turned off. As a result,...
This circuit is from an English magazine from 1976. By replacing the transistor for a BC548, the...