Chain motor power distribution and control

Abstract

Units for distributing three-phase power to a plurality of chain motors are provided, as are used to raise and suspend production elements such as lighting, sound, video, and scenery. Remote switching and phase reversal of such power are also provided. In the prior art, such switching has been performed by large, heavy contactors inserted between the single power input and its distribution to plural outputs for motors, making the unit difficult to handle and ship. Provided herein are power switching and phase reversal performed by a plurality of parallel such means, reducing the current requirements for each, and thereby the size, weight, and cost of the whole. In some embodiments, the single power input is replaced by a by a cable delivering a plurality of two-phase circuits to the unit which derives the three-phase circuits necessary for chain motors therefrom.

Dependencies are inferred from the claim text.