This Kirlian machine circuit uses a car ignition coil. The circuit is from a Radio Electronics from May 1986. It is mentioned in an article that teaches how to obtain photographs.
The automatic modulated siren circuit shown in the figure really produces an interesting sound...
This circuit was found in the August 1973 issue of Radio Electronics magazine. The Darlington...
This circuit has three settings, central sound frequency, modulation speed and modulation depth. The...