| 摘要 |
PROBLEM TO BE SOLVED: To determine whether a partial switching circuit is normal or abnormal.SOLUTION: A power supply circuit 10 includes: a reactor 11 connected to one end of a single phase commercial power supply AC; forward converting circuits 12 and 13 connected between the other end of the reactor and the other end of the commercial power supply, and supplying direct-current power to a load (an inverter 2); a partial switching circuit 14 connected to the forward converting circuit side of the reactor through a fuse 15, and sequentially executing short-circuit/open-circuit between the other end of the commercial power supply and the partial switching circuit; and a control portion 9 which performs feedback-control on pulse width of a control pulse for controlling the partial switching circuit so as to make direct-current voltage applied on the load become target voltage. The control portion varies the control pulse width or the target voltage when the direct-current voltage is out of the target voltage width, determines as normal when the direct-current voltage applied on the load follows the change, and determines as abnormal when the direct-current voltage applied on the load does not follow the change. |
