Abstract: An inverter for supplying electrical energy from a DC supply to a load, includes a flyback transformer having a primary winding circuit coupled to the DC supply, and a secondary winding circuit coupled to the load. The primary winding circuit includes a first switch for interrupting the DC supply causing energy to be stored in the transformer, and the secondary winding circuit includes a second, unidirectional switch to produce an output of one sign when closed. The primary winding circuit further includes an electrical device effective to return energy to the DC supply only when the first and second switches are open.

Abstract: A truss comprises a pair of spaced, longitudinally-extending bars (or only one such bar), and a plurality of transversely-extending, or diagonal, bars occupying a common plane. One longitudinally-extending bar is disposed in a plane laterally spaced from the common plane on one side thereof, and the other logitudinally-extending bar (when included) is disposed in a plane laterally spaced from the common plane on the opposite side thereof. Such a structure permits a plurality of the trusses to be stored or transported in nesting relationship in order to occupy a minimum volume, and also permits each truss to serve as a modular element enabling any desired number of them to be secured together in building a structural framework of the desired configuration and strength.