Patent ID: 7382598

Claim:
A device for controlling a coil arrangement ( 10 ) with electrically variable inductance, the coil arrangement ( 10 ) having at least one control winding ( 12 ) and two working windings ( 14 , 16 ) connected in parallel which are placed on a core material, said device comprising: a control circuit ( 18 ) which delivers a control current to the control winding ( 12 ) in order to vary the inductance of the coil arrangement ( 10 ), and a demagnetization circuit ( 22 ) which generates an inverse voltage pulse and applies it to the control winding ( 12 ) in order to accelerate the change in inductance of the coil arrangement ( 10 ); wherein the demagnetization circuit ( 22 ) includes a single-pulse generator ( 24 ) connected to the control winding ( 12 ) through a control switch (S 1 ) and wherein the duration of a pulse from the single-pulse generator is a function of the absolute value of the control current applied to the control winding immediately before switching the control switch.