Patent ID: 6862197
Filing Date: 2005-03-01
Classification: H02M,Y02B

Abstract:
1. An arrangement for demagnetization of a transformer (TR) in a single-ended forward DC/DC converter, a primary winding (N 1 ) of the transformer being connected in series with a primary switch (V 3 ) to a source (U 1 ) of varying input DC voltage, a diode (D 1 ) being connected in series with a capacitor (C 1 ) across the primary winding (N 1 ) for transferring magnetization energy from the transformer (TR) to the capacitor (C 1 ) during the off period of the primary switch (V 3 ), and a discharging circuit being connected across the capacitor (C 1 ) in order to dissipate magnetization energy stored therein, characterized in that the discharging circuit comprises means for discharging the capacitor (C 1 ) with such a DC current (I) in response to the varying input DC voltage that complete demagnetization of the transformer (TR) always is attained just before turn-on of the primary switch (V 3 ).