System for controlling a one role synchronous motor in accordance with a measured back EMF

摘要

A system controls a one-pole synchronous motor, with a magnetized rotor and a stator provided with two pairs of coils. The motor includes a floating common node to which are connected first coil terminals, the second terminal of each first coil of a coil pair is connected to a first supply terminal through a first respective switch, and the second terminal of each second coil of a coil pair is connected to a second supply terminal through a second respective switch. The control system includes a circuit operable for controlling switches in a stepping or self-switching mode, and at least one detection circuit using the voltage occurring at the floating common node so as to detect at least one operation condition of the motor.