| 摘要 |
PURPOSE:To make an acceleration rate stable and obtain a smooth acceleration, by controlling an operating motor that drives a secondary resistor to have a variable speed corresponding to an intensity of a primary current of an induction motor. CONSTITUTION:When a value of speed command SP is given to a motor 1, a regulator 11 closes a contact 11a1. Then a command valve VP of a speed command circuit 16 is applied to a comparator 19, and with a deviation from an actual value VF applied to a phase control circuit 20 an operating motor 13 is driven. At the time, the circuit 16 gives an output so that the weaker a primary current I1 becomes the greater the value of speed command VP becomes. Therefore when the motor 1 is in a state of accelerated speed, a motor 13 is driven with variable speed by an intensity of the primary current so that a speed control corresponding to an acceleration current can be performed. If the load is greatly changed or the set speed SP is surpassed by some over-performances of a liquid resistor, an output of an amplifier 17 changes greatly a value of the liquid resistor to cause the motor 13 to rotate reversely through a control amplifier 18. |
