Power is fed from a pair of power supplies to each one of a plurality of load circuits through a distributed power switch. A plurality of switch means are each associated with a respective one of the load circuits for connecting it to one of the power supplies in a primary manner and to the other power...http://www.google.com/patents/US3949238?utm_source=gb-gplus-sharePatent US3949238 - Distributed power switch for modular systems
