Electric motor and motor control system

摘要

The system comprises sensors (PS) for detecting the angular position of the rotor (R) of the motor and a driver circuit (DC) arranged to control conduction in the controlled switches (SW) associated with the phases (W) of the motor and in a regulation switch (RSW) in predetermined manner in dependence on the position signals emitted by the sensors (PS). The regulation switch (RSW) is driven in an on/off manner by means of a square-wave signal. The system further comprises a protection circuit (PC) with a capacitor (C) connected to the control input of the regulation switch (RSW) so that the capacitor (C) is charged each time the regulation switch (RSW) is made conductive by the square-wave signal in operation, and with a control switch (T) connected between the control input of the regulation switch (RSW) and a pole (GND) of the direct-current supply and having a control input connected to the capacitor (C). The control switch (T) is made conductive and cuts off the regulation switch (RSW) when the latter remains conductive continuously for a period of time longer than a predetermined period.