Apparatus for measuring at least one state variable of a brushless direct-current motor

摘要

The temperature of a brushless d.c. motor is measured in operation by making the pole segments 2 of the rotor 1 of the motor of permanently magnetic material. and by use of at least one Hall-effect element 4 so disposed with respect to the rotor that the magnetic field of the permanently magnetic segments is impressed on the output voltage from the element; a logic unit then determines the temperature of the brushless direct-current motor from the output voltage of the Hall-effect element. Various ways of processing the element output voltage are described. Rotor speed and direction may also be determined. To improve speed resolution, the magnetic rotor segments may be subdivided.