We found this circuit in an old documentation for radio amateurs. The circuit uses an analog indicator. The characteristics of the coils are given next to the diagram.
We found this circuit in the December 1998 issue of Electronics Now magazine. RF transistors such...
This circuit was found in an American documentation from the 80's. The sensor is a special...
This circuit automatically controls the degree of illumination. As the circuit is from 2001, it...