| 摘要 |
PURPOSE: To simplify a structure of a power-supply unit and to realize the effective use of a converter or an inverter by providing a conversion switching circuit for controlling a transistor to be operated by taking an AC-DC converter as a DC-AC inverter in the case of power failure. CONSTITUTION: In the case of power failure, a conversion switching circuit 8 connects a power failure AC-DC converter control circuit 82 to a power supply through the contact NPX of a power supply monitoring auxiliary relay 83 and controls a transistor so that a transistor drive circuit 84 may be operated by taking an AC-DC converter 2' as a DC-AC inverter. While, a battery 5 supplies electric power to a motor controlling DC-AC inverter 3 through a contact NP at power failure to drive a motor 4. Simultaneously, the battery 5 supplies direct current to the AC-DC converter 2' through the contact NP, boosts alternate current converted from direct current under control of the conversion switching circuit 8 by a booster transformer 9 through the contact NP, and supplies it to a controller of an elevator. |
