Patent ID: 7859870
Filing Date: 2010-12-28
Classification: H02M,Y02B

Abstract:
1. A dc-to-dc power converter for generating load voltage, said power converter comprising a phase-shifted pulse-width-modulated bridge; said bridge including at least first and second controllable switches, each controllable switch including a controllable current path and a control input port, said controllable current paths of said first and second controllable switches being connected as a first half-bridge with a first tap, a first connection node adjacent said first controllable switch and remote from the first tap, and a second connection node adjacent said second controllable switch and remote from said first tap, said first connection node being connected to energizing voltage of a first polarity from a first terminal of a source of direct energizing voltage, and said second connection node being connected to energizing voltage of a second polarity from said source of direct energizing voltage; said bridge further including third and fourth devices, each including a current path, said current paths of said third and fourth devices being connected as a second half-bridge with a second tap, said second half-bridge being connected to said energizing voltage of a first polarity from a first terminal of said source of direct energizing voltage, and to said energizing voltage of a second polarity from said source of direct energizing voltage; a phase-shift pulse-width-modulated controller coupled to at least said control input ports of said first and second controllable switches, for switching the controllable switches so that a fixed-frequency alternating voltage appears between said first and second taps of said half-bridges with a duty cycle selected to provide a desired converter load current; an output transformer including primary and secondary windings, said primary winding of said output transformer being coupled to said first and second taps, so that said alternating voltage is applied to said primary winding of said output transformer; a full-wave rectifier connected to the secondary winding of said output transformer, for rectifying secondary winding current flowing under the impetus of said alternating voltage; a filter coupled to said full-wave rectifier for producing output direct voltage for application to a load, whereby resonances may generate surges which may undesirably result in energy loss; a second transformer including a primary winding coupled to receive said surges and a secondary winding at which transformed surges are produced; a second rectifier coupled to said secondary winding of said second transformer and to one of said load and energizing voltages, for rectifying said surges and making the energy of said surges available to said one of said load and energizing voltages.