US 5,122,947 AGranted

Flyback transformer having coil arrangement capable of reducing leakage of magnetic flux

AssigneeVictor Company of Japan, Ltd.

InventorHideo Hishiki

Life of this patent

Estimating the term…

Loading patent…

Abstract

A flyback transformer comprising a magnetic core assembled by joining together a pair of first and second U-shaped core halves each having two leg portions with end surfaces respectively joined in mutually abutting confrontation with respective gap spacers interposed therebetween at first and second core joint parts and a coil wound around the core joint parts. The coil includes, as an input winding, a primary winding divided into first and second primary windings which are wound at least around the two core joint parts of the core and are connected in parallel. By this arrangement, the magnetic fluxes generated at the two core joint parts cancel each other, and reduce the leakage flux field. Optionally, the two divided windings of the primary winding are each divided further into two windings wound around the leg portions on opposite sides of the spacers. At the same time, the first primary winding on the leg portion on one side and the second primary winding on the other side are connected in series. Furthermore, the first primary winding on the leg portions on the other side and the second primary winding on one side are connected in series. The coil includes, as an output winding, a secondary winding which can be operationally divided into at least two windings wound so as to envelop each of the two joint parts to thereby reduce the leakage flux.

Claims13

Dependent claims

A flyback transformer comprising a magnetic core which is assembled by joining a pair of first and second magnetic core halves each having two leg portions, said core halves joined at respective two end surfaces of said leg portions thereof in mutually abutting confrontation with respective gap spacers interposed therebetween thereby to form a closed-figure magnetic core having first and second core joint parts and primary coil means around said core joint parts and secondary coil means wound over said core joint parts and secondary coil means wound over said primary coil means, and said coil joint part, and a second winding wound around said second core joint part, and said first and second windings being connected in parallel to function as an input winding;

wherein said first primary winding is divided into two windings wound around respective leg portions of said first core half near, not around, said gap spacers, one winding of said first primary winding is wound near said first core joint part being connected electrically in series with one winding of said second primary winding wound near said second core joint part, and the other winding of said first primary winding is connected electrically in series with the other winding of said second primary winding;
said flyback transformer further including a secondary winding and tertiary winding wound around and completely enveloping the first and second primary windings which are wound around either one of said core joint parts, said secondary winding and said tertiary winding functioning as output windings to thereby reduce the leakage flux field to a minimum;
and wherein said secondary winding is wound densely as an outermost winding and said tertiary winding is densely between said first primary winding and said secondary winding.

A flyback transformer comprising a magnetic core which is assembled by joining a pair of first and second magnetic core halves each having two leg portions, said core halves joined at respective two end surfaces of said leg portion thereof in mutually abutting confrontation with respective gap spacers interposed therebetween thereby to form a closed-figure magnetic core having first and second core joint parts and primary coil means wound around said core joint parts and secondary coil means wound over said primary coil means, and said coil means including a first primary winding wound around said first core joint part, and second primary winding wound around said second core joint part, and said first and second windings being connected in parallel to function as an input winding;

wherein said first primary winding is wound around and completely envelopes one of said first and second core joint parts, and said second primary winding is wound around and completely envelopes the other core joint part;
and wherein said transformer further includes a first secondary winding functioning as an output winding and wound tightly around said first primary winding in correspondence thereto to reduce the leakage flux field to a minimum, a second secondary winding functioning as an output winding and wound tightly around said second primary winding in correspondence thereto to thereby reduce the leakage flux field to a minimum, and a first tertiary winding functioning as an output winding and wound tightly between said second primary winding and said second secondary winding.

Dependencies are inferred from the claim text.