It`s used for soothe regulation of AC voltage with frequency 50 Hz in range from 0 to 30 V and DC (pulsating) voltage with pulsation frequency 100 Hz in range from 0 to 24 V. Voltage generator must have supply voltage - 220 V with output voltage changes in range from 0 to 30 V (AC) and in range from 0 to 24 V (DC) at maximum current load under 10 A.