of the induced electromotive force is distorted as shown in fig2 b and an effective value becomes small on the other hand in the claw pole motor whose core is constructed of the smc since an eddy current hardly flows it becomes an effective value of the induced electromotive force linear to a frequency revolution speed hence although the conventional claw pole type motor with the conventional claw poles could not be used for an application at high revolution speed the claw pole motor constructed of the smc core can be driven at high revolution speed high frequency area in addition because the eddy current hardly flows it is also possible to correspond to a pwm method of control system which performs a pulse division of a sinusoidal voltage and driving pwm is a drive system of obtaining an effective value of a voltage in a pulse like voltage since a switching frequency of those pulses is usually about 10 times of a maximum frequency of a drive current of a motor that is a very high frequency an eddy current arises by its rf component hence since iron loss becomes large in a conventional claw pole motor constructed from iron plates the motor has become an inefficient motor since the eddy.