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 is suggested by National Semiconductor and is based on a double operational amplifier of...
This electronic roulette circuit with 10 numbers was found in a Popular Electronics from the 80s....
For measurements between 30 and 40º C this circuit was found in the documentation of 1968. The...