FIELD: electrical engineering. SUBSTANCE: device used for raising saturable reactor speed of response to power increase and decrease in transients has controlled circuit-changer switches in the form of power thyristors, transistors, or triacs. Energizing reactor working coil makes acquiring rated conditions due to additional saturation of core by current pulses in signal winding coils changed over by means of respective controlled switches during desired number of half-cycles of voltage induced in them. Power reduction is effected by means of same switches at reverse polarity of voltage induced in coils which builds up additional magnetic flux causing demagnetization of closed core legs of controlled reactor. Closing circuit- changer switches to controlled part of each half-cycle of voltage induced in signal winding coils enables stepless variation of reactor transient characteristics and fast setting of any desired power level under steady state conditions. EFFECT: enlarged functional capabilities, simplified design, reduced size and cost. 1 dwg
