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Control apparatus for elevator

  • US 4,666,020 A
  • Filed: 04/21/1986
  • Issued: 05/19/1987
  • Est. Priority Date: 04/22/1985
  • Status: Expired due to Fees
First Claim
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1. A control apparatus for an elevator comprising a converter which converts electric power of an A.C. power source in a normal state into direct current while the A.C. power source is normal and which has a battery connected thereto and operates as a step- up chopper when the A.C. power source stops, a capacitor which smooths the output of said converter during the normal state of the A.C. power source and which is charged to a voltage double that of the battery during the stoppage of the A.C. power source, an inverter which receives the voltage of said capacitor to invert it into alternating current of variable voltage and variable frequency and which supplies the alternating current to an electric motor for driving the cage of the elevator, and a control device which controls said converter in pulse width modulation during the normal state of the A.C. power source and controls it as the chopper during the stoppage of the A.C. power source.

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