UNIPOLAR INVERTER TOPOLOGY FOR SIMULTANEOUS DRIVING OF BRUSHLESS DC MOTORS

摘要

The present invention relates to a converter circuit for driving a first brushless DC electric motor and a second brushless DC electric motor of an electrical household appliance, the converter circuit comprising a first motor unipolar inverter (1) controlling energy flow to the first brushless DC electric motor by means of first motor switching devices (9) energizing a respective first motor phase winding (3) in timed sequence and a second motor unipolar inverter (2) controlling energy flow to the second brushless DC electric motor by means of second motor switching devices (10) energizing a respective second motor phase winding (4) in timed sequence, the converter circuit having positive and negative supply lines (13, 14) forming common connection points for the second motor phase windings (4) that are in series with the second motor switching devices (10) and freewheeling diodes (7) in association with a respective second motor switching device (10) effecting current flow to a freewheeling line (15) when the latter switching device is opened.