This circuit featuring a new quadruple operational amplifier was found in the March 1980 issue of Radio Electronics magazine. The circuit is to be powered by a symmetrical 15 V source.
This circuit, for automotive use, was obtained in a European publication from the 1980s. The...
This two-transistor circuit was found in the January 1994 issue of Electronics Now. The circuit can...
Found in a Popular Electronics from the 90s, this circuit can be adapted to use LEDs. The power...