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 circuit with JFET and Unijunction was found in an ancient American documentation. The...
This metering bridge circuit uses one power supply only. The operational ones depend on the...
We found this configuration in the 1964 RCA transistors manual. As indicator loads in each stage,...