This is another of the circuits with the LM380 that we have in this section. We found it in an article about Walkman amplifiers in the Radio Electronics magazine of March 1986.
In the figure we have an improved method of varying the voltage of a 7812 regulator. The circuit is...
This 5-range current measurement circuit was found in the September 1989 issue of Radio...
Found in an old English publication this circuit uses a dual gate MOSFET. Coils not specified....