Patent ID: 6838842

Claim:
A method for operating a brushless synchronous d.c. motor ( 1 ) comprising the following steps: a) supplying a d.c.-voltage as an input voltage (U E ) to said brushless synchronous d.c. motor ( 10 ) for commutating motor phase windings, b) performing a linear closed loop control of an input voltage (U E ) in a first r.p.m.-range ( 12 ) up to an r.p.m.-threshold value (n S ) for varying an r.p.m. (n M ) of said brushless synchronous d.c. motor ( 10 ), and c) performing, when said r.p.m.-threshold value (n S ) has been reached, a vector closed loop control of the input voltage (U E ), in a second r.p.m. range ( 13 ) having a higher r.p.m. (n M ) than said first r.p.m.-range ( 12 ) of said brushless synchronous d.c. motor ( 10 ).