| 摘要 |
<p>Series circuits consisting of diodes for blocking reverse currents are inserted between the upper and lower arms of bridge-connected transistors constituting an inverter, and contacts of a contactor adapted to close upon a stoppage of power supply are respectively connected in parallel with the series circuits so as to short-circuit the series circuits of the diodes, whereby the inverter is changed-over from a current type inverter to a voltage type inverter upon the stoppage of the power supply. Thus, even in an elevator employing the current type inverter, a rescue operation during the stoppage of the power supply can be performed with a simple circuit arrangement employing a D.C. power source.</p> |
