| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect a rotor stop position.SOLUTION: The present invention has: position signal generation means which generates a signal instructing a plurality of predetermined energization patterns for electric current to be flown to a coil having a plurality of phases; an inverter circuit which supplies electric current to the coil by a signal from the position signal generation means; electric current measurement means which is used for measuring electric current to be flown to the coil; electric current comparison means which outputs a detection signal when an electric current value measured by using the electric current measurement means becomes a predetermined threshold value or larger; a counter counts time until the detection signal is output from when a signal which instructs the energization pattern is output, for each energization pattern; and position estimation means which determines a rotor stop position from a map in which differences between energization times of the energization patterns which are continuously energized are associated with the rotor stop position according to the differences, among the plurality of energization patterns. |
