This circuit can detect static charges or extremely low voltages. The circuit was found in ancient American documentation and makes use of a JFET. A BF245 which is a more modern transistor can be used.
This circuit allows 220 / 240V shavers to be used in the 110V network. The diodes can be general...
Found in July 1975, Radio Electronics magazine this circuit can use any operating circuit,...
Here we have in the figure the configuration of the circuit as a conventional Darlington. In this...