Three coil bridge transformer

Abstract

The magnetic core of the transformer is an E--E shaped core. The primary winding of the transformer is divided into three substantially identical planar coils, each coil being wound on one of the three separate core posts. The coils are wired in series such that a current in the primary winding will induce substantially identical magnetic fluxes in the two outer core posts, and an opposite flux in the center post. The secondary of the transformer is formed by a contact plate and a conductor frame which provide conducting paths through the window regions of the E--E core. The bottom of the core is mounted in a recess in the conductor frame. Positioned within in the conductor frame are four rectifiers which make electrical connections to the secondary contact plate. When the transformer delivers power, the voltage on the primary winding will be divided 1/4 on each of the outer coils and 1/2 on the center coil post. During this time only two of the rectifiers will be conducting current. During freewheel times, with no primary voltage, the load current will divide evenly among the four rectifiers. During commutate intervals, between freewheel and on times, the voltage on the primary winding will divide evenly among the three coils. This novel transformer permits a switch mode power supply to supply more power while providing more even cooling.