This circuit was found in a 1964 Electronic Design. The components are of the time, and modern equivalents can be used. Note the multi-emitter transistor.
This normally open, two-terminal, high-sensitivity circuit was found in General Electric's...
Bubba's oscillator, shown in the figure, is another type of phase shift oscillator, but it takes...
This sensitive electroscope uses a MOSFET 3N128 and can detect electrostatic charges of objects....