| 摘要 |
PURPOSE:To obtain high brake force in the full speed range without using another DC power source by utilizing a motor drive DC power source for a brake, and DC braking the motor at the low speed time for the induction generative brake. CONSTITUTION:The output voltage V2 of a function generator 17 is lowered at a constant speed by applying a stop signal STP, thereby sequentially decelerating a motor 11. The counterelectromotive force of the motor 11 is presented between lines 12a and 12b through diodes 10a-10f, and when the difference between the output voltage Va of the chopper 2 and the voltage V2 becomes larger than the output voltage V4 of a vias voltage setter 33, a transistor 14 is turned ON by a comparator 31, and the counterelectromotive force is consumed by a resistor 13. The motor 11 is decelerated by the induction generative brake, the voltage Va is switched so as to becomes smaller than the output voltage V5 of a switch voltage setter 37. Then, a timer 21 outputs a signal by the comparator 35 and an AND circuit 38. In this manner, a 3-phase distributor 20 continuously turns ON only transistors 9a, 9f, thereby DC braking the motor 11. |
