This circuit was found in the magazine of radio amateurs 73 in a 90's edition. The components are current and the transistor is of general use.
This 2004 circuit is based on the ionization effect that occurs in old incandescent lamps with...
This bidirectional current sensing circuit was found in a 2005 Linear Technology application manual....
This circuit can be used in decoration or to draw attention, in a “fake” assembly for example. What he...