This is one of the many versions we have of a 12 V power supply with the 7812. We found it in the Radio Electronics magazine of July 1984. The integrated circuit must be mounted on a heat sink.
This circuit using an operational amplifier was found in old American documentation. It can be...
If the circuit oscillates, emitting sound, it is because the transistor is good. This simple...
Like the previous circuit, this is used in the analog part of the telephone lines. The same...