| 摘要 |
PURPOSE:To protect an inverter from overcurrent by providing a protective circuit that operates if a first detector continues detecting the inverter output exceeding a first current level for over a given time or if a second detector detects the inverter output exceeding a second level current. CONSTITUTION:The output current of an inverter device 1 is detected by an inverter output current detector (AD) 7 and conduction time is counted by a conduction time counter 4 when an output current exceeding the first detection level set by a first level comparator 8b is detected. Then, when a specific allowable time is exceeded, H is output to an OR gate 5. Also, when a second detection level where the detection current value of the AD 7 is stored is exceeded by a second level comparator 9b, H is output to the OR gate 5. The first detection level is set greater than the second detection level, thus enabling an inverter control circuit 6 to protect the inverter device 1. |
