| 摘要 |
PCT No. PCT/GB94/01165 Sec. 371 Date Feb. 22, 1996 Sec. 102(e) Date Feb. 22, 1996 PCT Filed May 27, 1994 PCT Pub. No. WO94/28618 PCT Pub. Date Dec. 8, 1994A method of driving an electric motor having at least one coil winding comprising using a switching operation when the current in the winding is to be switched from a first state to a second state. The switching operation has at least first and second switching steps, the interval between which is approximately equal to half the period of a dominant frequency of vibration of the motor (or to an integral multiple of the period plus a half). This reduces vibrations causing acoustic noise, enabling the motor to be operated more quietly. One or more intermediate steps may be included in the switching operation. |
