| 摘要 |
PURPOSE:To reduce noise by applying the specific optimum current to a power source coil so as to eliminate a high frequency component from excitation force. CONSTITUTION:A target current set by a target current value generator 2, in other words, a current having a target wave form is given to an electromagnetic coil 5, and then, an actually given current wave form is compared with the target wave form by means of a comparator 3 and is amplified so as to have no deviation, and consequently, the current wave form to be provided to the electromagnetic coil 5 is formed into the preset target wave form. Then, the current to be provided to the electromagnetic coil 5 is formed into a sine wave form of I(t)=(8/3pi)XI0X[sinomegat-(1/5)sin3omegat-(1/35)sin5omegat...], so that high frequency components are prevented from being contained in excitation force. |
