| 摘要 |
PURPOSE:To prevent impression of overvoltage on an inverter by driving the inverter in phase when a motor current is over the mormal value. CONSTITUTION:A resistor 40 holding data of a current limiting value is installed, and the output of a D/A converter 41 converting this data into an analog value is compared with a motor current. When the motor current exceeds the limiting value, a current limiting interrupt is generated by an output of a comparator 42, and ain inverter is driven in phase. An interval interrupt is generated in every fixed period in order to release current limiting to work an interval task. Furthermore, a current limiting task and a stop task are carried out. The forme task is to put into the next ready-to-inter-rupt state after generation of current limiting interruption and the latter is a stop task to put the system into a state to cut off a motor in emergency with the number of current limiting interrupt generation specified. |
