| 摘要 |
An elevator wherein an electric motor for driving the cage of the elevator is driven by the use of alternating current produced by an inverter, comprising a converter which feeds D.C. power to the inverter and which is so arranged that a plurality of transistors are connected into a bridge corresponding to the number of phases of an A.C. power source connected on the input side of the converter and that diodes are connected to the respective transistors in inverse parallel relationship. In addition, a battery to be used in emergency is connected on the input side of the converter. The converter is controlled in the pulse width modulation in the normal state of the A.C. power source, and the converter connected to the battery is controlled as a chopper during the stoppage of the power source, thereby making it possible to run the elevator at high speed even with the battery of low voltage.
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