The figure shows a typical circuit of a variac with a special transformer with sliding adjustment of the winding turns. The circuit is from an Electronics Now magazine from December 1997.
This Colpitts oscillator with JFET has the amplitude of the signals stabilized by a diode. The...
This circuit is from European 90s documentation. The integrated circuit used is not very common...
This circuit of an old publication makes use of SCRs that admit modern equivalents. The frequency...