Found in an Electronics World of 1966, this circuit makes use of FETs of the time. Modern equivalents can be used. The high voltage supply suggests its use with tube amplifiers.
This circuit is suitable for applications in medical, research and industrial equipment. The...
Of course, the design indicates a specific application for a touch switch. Thus, analyzing the...
With this 1-transistor circuit we have a high input impedance and good gain. The circuit is from a...