This powerful motor control was found in a Philips publication from 1970. The components are from that time and the circuit was designed for the 220/240 V power grid.
This operational amplifier circuit with variable gain was obtained in an 80's Electronic...
The circuit shown was obtained in American documentation from 1968. MOSFETs can be replaced by...
We found this circuit in a Popular Electronics from the 80s. This circuit eventually doesn't work with...