A power supply control device turns off energization of coils from a power supply device when a rotational speed of a motor reaches 500 rpm. After elapsing of one electrical cycle from the time of starting the turning off of the energization, a comparator of a correction device outputs a comparator signal, which is obtained by comparing a voltage of a neutral point of the coils and an induced voltage of the coil. An EX-OR circuit outputs an EX-OR signal, which is an exclusive OR value of the comparator signal and an output signal of a Hall sensor. A sensing unit obtains an electrical angle of a period, during which the EX-OR signal is in a H-level. A difference between the obtained electrical angle and a standard electrical angle of 30 degrees is stored as a correction data value. Thereafter, energization of the coils is restarted.