Patent ID: 8817491

Claim:
A system, comprising: a transformer having at least four taps on its primary; four switching elements forming an H-bridge with the primary, wherein first terminals of the first and fourth switching elements are connected to the first and fourth taps, respectively, and second terminals of the first and fourth switching elements are connected at a node; fifth and sixth switching elements, wherein first terminals of the fifth and sixth switching elements are connected to the second and third taps, respectively, and second terminals of the fifth and sixth switching elements are connected at the node; and a controller configured to operate in at least two modes such that, in the first mode, the first and fourth switching elements alternately conduct to produce a complete output waveform and the fifth and sixth switching elements remain turned off, and in the second mode, the fifth and sixth switching elements alternately conduct to produce the complete output waveform and the first and fourth remain turned off.