| 摘要 |
PURPOSE:To enable to stop an induction motor precisely although the inertia moment of load is variable by a method wherein a detector detecting a speed in the time of plugging braking and a delay circuit instituting the delay time of the breaking of control power source from the time of speed detection are provided. CONSTITUTION:A load 1 is stopped by the operation of a control device 4 performing a plugging braking on an induction motor 2. After the start of braking, an off- warning signals S1 generating in a speed detector 5 is inputted to a delay circuit 6, and is also inputted to a braking time measuring circuit 7 to output to the delay circuit 6 a delay time command Sd being defined in accordance with the time from a brake start signal SO to the signal S1 and an off-command signal S2 is outputted from the delay circuit 6 to a controller 4 at a time being delayed in accordance with the signal Sd from the inputtting time of signal S1 to stop the reverse braking. Therefore by making the value of delay time to be proportional to the inertia moment of a load, the motor can be made to stop although the inertia moment of load is changed. |
