This circuit was found in a 1969 Motorola documentation. The FET admits an equivalent. The circuit has high input impedance and is powered by voltages from 6 to 30 V.
Another dimmer circuit. This dimmer for incandescent lamps was found in the July 1970 issue of...
This shield was found in an American documentation from the 70s. The operational amplifier is from...
The integrated circuit used is not very common today. Transistors can be replaced by more modern...