This circuit is from an Electronics World of 1968. The transistors are of the time and the power is supplied with a voltage of 40 V. The circuit is high fidelity.
Using the name of varactor this circuit was found in the Radio Electronics magazine of July 1982....
We found this source with the CI 723, common at the time, in a 1989 paper. Power transistors must be...
This simple circuit indicates if the polarity of a load is reversed when it is connected to a...