Patent ID: 6759820
Filing Date: 2004-07-06
Classification: H02P

Abstract:
An arrangement for powering a DC motor (12) from a DC power supply, comprisinga DC link circuit (14, 22; 16, 141) adapted to be coupled to said DC motor and having a capacitor (21) associated therewith, adapted to temporarily supply energy to said DC motor; a first regulator (30; 146) for connecting the DC link circuit to the DC power supply, which feeds a substantially constant current (i) via a transistor (24), serving as a linear adjusting element, to said capacitor (21) and to the DC motor; wherein a voltage drop (UT) arises at said transistor (24); and further comprising a second regulator (34; 144) which supplies a target value (U32, U188) to an input of said first regulator (30; 146), said second regulator having an input adapted to be supplied with an actual voltage value derived from a voltage (UZK) across said DC motor, whereby said second regulator (34; 144) adapts said target value (U32, U188) for said first regulator to varying loads of the DC motor (12) and thereby minimizes audio-frequency electrical fluctuations at supply leads (14, 16) of said motor and minimizes resulting electromagnetic noise.