| 摘要 |
PURPOSE:To obtain a control apparatus of a motor which is resistant to a noise and avoids a dangerous state for safety's sake by a method wherein a switching state of an inversion means is detected as an optical signal and this optical signal is transmitted to a control means. CONSTITUTION:An alternating-current output from an alternating-current power supply 1 is converted into a direct current by using a power rectifier 2; this direct-current output is converted into an alternating current corresponding to a motor velocity by using an inverter 4 constituted of a transistor; the transistor of the inverter 4 is controlled on the basis of a pulse-width modulation by using a control means. Then, the transistor of the inverter 4 is detected by a switching-state detection part 17; this detection result is output as an optical signal; the optical signal of the switching-state detection part 17 is transmitted to the control means by using an optical transmission means; the control means drives and controls the transistor of the inverter 4 on the basis of the optical signal of the optical transmission means. The switching-state detection part 17 is provided with resistances 19, 25 which limit an electric current flowing to optical modules 18, 24, 30 with built-in light-emitting elements. |
