ROTATION POSITION DETECTOR

摘要

PROBLEM TO BE SOLVED: To facilitate a stable operation against the fluctuation of a load by a method wherein a means by which an offset signal is generated in accordance with an exciting current detection signal supplied from a motor is provided in a rotation position detector. SOLUTION: A rotation position detector 1 generates an index signal (h) in accordance with a rotor position detection signal (b) which is supplied from a rotor position detecting means 7 and an exciting current detection signal Vnf which is supplied from a driver 9. An offset correcting means (OF) 10 generates an offset signal Iof in accordance with the exciting current detection signal Vnf and supplies the signal Iof to a differential amplifying means 11. Further, the OF 10 converts the exciting current detection signal Vnf corresponding to the exciting current value of an armature coil 6 into the offset signal Iof which is a constant current signal and supplies the signal Iof to the input stage resistor Rof of the differential amplifying means 11. That is, the rotor position detection signal (b) which is distorted by the influence of a magnetic field generated by the armature coil 6 can be corrected by the offset signal Iof.