This circuit was found in the March 1997 Electronics Now magazine. It uses a common analog indicator and the transistor is a general purpose one.
This circuit is from a Radio Electronics from April 1972. The circuit uses power transistors of...
We found this simple circuit in a 1999 documentation. It converts low-intensity sinusoidal signals (a...
This very high voltage circuit was found in the 1990 special issue of Radio Electronics...