Found in McGraw Hill documentation from the 1990s, this circuit supplies high voltage to the electrodes of a Kirlian machine. High current MOSFETs can be used.
This circuit was found in an old American publication. The integrated circuit used is no longer easy...
Using a transconductance operational amplifier, this circuit was found in July 1983 Radio...
This battery-powered emergency light circuit was published in an April 1962 Radio Electronics...