| 摘要 |
The system (ECS) comprises a rectifier circuit (RC) to supply a direct current voltage (VB) as output; a driver circuit (DC) which is connected to a rectifier circuit (RC) and includes a plurality of controlled switches (SW1-SW4) which can permit passage of a current in the stator winding (W) selectively in one direction and in the opposite direction; a sensor (PS) which can supply a signal (H) which is indicative of the angular position of the rotor (R); and a control circuit (CC) which is designed to receive a signal (RS) which is indicative of the speed of rotation required (ωref) for the motor (M), and is connected to the position sensor (PS). The control circuit is designed to generate, from the passage of the rotor (R) to a predetermined position, a counting signal (N) which is a function of the time (t), and to reset this signal (N) when it reaches a predetermined value (Nref) corresponding to the speed of rotation required (ωref) for the motor (M); and then to control the driver circuit (DC) selectively on the basis of the position signal (H) of the rotor or on the basis of the counting signal (N), when the speed of rotation (&Dgr;) of the motor (M) is respectively lesser and greater than the speed required (&Dgr;ref). |
