This circuit was found in an American documentation from the 70s. The operational amplifier is from that time. Modern equivalents can be used.
This electronic variac has the traditional configuration with triac already explored on the site,...
With this oscillator we can obtain a signal of 10 W of power at the frequency of 100kHz. The...
This circuit is based on an LM3900 transconductance operational amplifier, found in 1992...