Patent ID: 6225775
Filing Date: 2001-05-01
Classification: H02P

Abstract:
A single-phase, synchronous electric motor comprising:a rotor with permanent magnets, with at least one pair of poles,a stator having a winding wound around a magnetic circuit,position-detecting means associated with the rotor for providing driving signals in dependence on the angular position of the rotor,and a driver circuit connected to the detecting means and to the stator winding and having a pair of terminals for connection to an alternating-current voltage supply, the driver circuit being arranged to control the flow of current in the stator winding in dependence on the signals supplied by the position-detecting means,said winding being divided into a first half-winding and a second half-winding connected to one another and wound around the magnetic circuit in opposite directions, and in that the driver circuit comprises first and second controlled-conduction means connected in series with the first stator half-winding and with the second stator half-winding, respectively, in respective circuit branches connected substantially in parallel between the supply terminals, the first and second controlled-conduction means having respective control inputs connected to the position-detecting means in an arrangement such that, during steady-state operation, respective unidirectional currents having a frequency equal to half of the frequency of the alternating supply voltage flow through the half-windings alternately.