With this circuit, using a single control voltage, you can increase the brightness of the lamp while the brightness of another decreases. The circuit applies only to incandescent lamps.
This power supply, found in an Argentine publication from the 1970s, uses a wire potentiometer of 25 W or more...
This circuit was obtained from an English magazine from 1979, but can be easily assembled today...
The oscillator shown in the figure generates a 1 kHz tone that is reproduced on the speaker with...