| 摘要 |
PURPOSE:To facilitate control of a looper by connecting in series a stator coil and rotor coil of 2-phase to make reversed phase rotation thereby applying to the coils the output of a control rectifier which is controlled by the output from a rotor rotation angle detector. CONSTITUTION:A looper 3 that gives tension to a strip 2 of rolling mill and the like is connected to an induction motor 18 consisting of 2-phase stator coils 19A-19B and rotor coils 20A-20B. Coils 19A and 20A are connected in series, 19B and 20B are connected in series with reversed polarities, to make reversed phase rotation, and each connected to a control rectifiers 22, 24. The output of a rotor angle detector 21 is applied to a sine wave function generator 29 to be multiplied by a command value. This output is compared with output current of the control rectifiers 22, 24 by a comparators 39, 40 to control a thyristor of the control rectifiers 22, 24. Thus, the device of simple construction eliminates the effects of ambient temperature and others while effectively controlling the looper 3. |
