The paper presents configuration and operating principle for noncontact tapping switch that can on-load regulate voltage automatically.

The bath temperature, liquidus and anode effect were controlled by adjusting the AlF3 additions, aluminum tapping magnitude, cell voltage set-point and the alumina feeding interval.

Adjustable voltage transformers, voltage output is 220v, 20v, 24v, 28v, tapping tapping efforts need to choose the time according to different voltage.