Found in the September 1972 issue of Radio Electronics magazine, this signal injector is based on the HEP580. The circuit is powered by two batteries and its frequency is basically given by C1.
This circuit mimics the trill of a bird. We found it in an American documentation from the 90s. It is...
Found in Radio Electronics from the 90s, this circuit uses a 741 and can be changed to other...
This power supply with several transistors can supply a current of several amps and a voltage of...