Emergency operating unit of value exchange elevator (非常 時 運轉 裝置)

摘要

A rectifier is connected to an AC power source to produce a direct current output which is conversely an inverter for converting the output into an alternating current output of a variable frequency. An AC motor is driven by the output of the inverter. An emergency power source is connected across input terminals of the inverter in the same polarity as the terminals. The emergency source has an output voltage which is selected to be lower than the voltage across the terminals of the inverter during normal operation.