| 摘要 |
PURPOSE:To stabilize the operation of a circuit while improving the characteristics of starting, by changing the feed currents of coils by detecting the saturation of semiconductors for controlling feed to each phase coil in response to the signals of a positional detecting means. CONSTITUTION:A rotor 5 for detecting locations turning with a rotor 1 generates high-frequency amplitude modulation signals to coils 9-14 for detecting locations wound on the projections of a stator 3, the signals are applied to transistors Q1- Q3 forming a three-differential amplifier and currents are fed to each phase coil X, Y, Z through transistors Q4-Q6. When Q4-Q6 are saturated, transistors Q9,Q7 are conducted through diodes D4-D6, electric potential Ec is decreased and currents supplied to each phase coil X, Y, Z are diminished by means of a current feedback system. Thus, the supersaturation of the transistors can be prevented, the operation of a circuit is stabilized and starting time can be shortened. |
