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.
Found in an Electronics Now from the 90s, this circuit with the 555 generates a signal with 50%...
Frequencies from 1 to 10 MHz can be obtained with a small adjustment of the variable in a narrow...
This is a multi-component tester with visual indication by LED and polarity selection in the test....