International Power Devices, Inc.

Fei Ma

Gang Xia

Qun Lu

Paul E Grandmont

James J Zeng

A single ended forward DC-to-DC converter includes a transformer having a. primary winding electrically connected to a primary switch and a secondary winding electrically connected to a secondary switch and a clamping capacitor. The clamping capacitor stores the magnetization energy from the secondary winding when the primary switch is turned off, thus causing the transformer core to be reset during the period that the primary switch remains off. The converter can use mosfets as the primary and secondary switches, such that a change in the voltage at the secondary winding of the transformer, due to the turning off of the primary switch, results in an automatic turning on of the secondary switch. The combination of the clamping capacitor and the mosfet switches increases the simplicity of the DC-to-DC converter while eliminating undesirable characteristics such as dead time and voltage stresses on the switches. The DC-to-DC converter of the present invention can be used to carry out synchronous rectification and zero voltage switching.

Single ended forward DC-to-DC converter providing enhanced resetting for synchronous rectification

A single ended forward DC-to-DC converter includes a transformer having a primary winding electrically connected to a primary switch and a secondary winding electrically connected to a secondary switch and a clamping capacitor. The clamping capacitor stores the magnetization energy from the secondary winding when the primary switch is turned off, thus causing the transformer core to be reset during the period that the primary switch remains off. The converter can use mosfets as the primary and secondary switches, such that a change in the voltage at the secondary winding of the transformer, due to the turning off of the primary switch, results in an automatic turning on of the secondary switch. The combination of the clamping capacitor and the mosfet switches increases the simplicity of the DC-to-DC converter while eliminating undesirable characteristics such as dead time and voltage stresses on the switches. The DC-to-DC converter of the present invention can be used to carry out synchronous rectification and zero voltage switching.

Single ended forward DC-to-DC converter providing enhanced resetting for

A planar winding assembly includes first and second windings, each winding having an axis and a pair of insulative sheet layers, laminated together, with at least one of each of the pairs of insulative sheets having a hole. Each winding further includes a metal strip conductor that is wound about the axis of its winding and is sealed between the laminated insulative sheet layers. The metal strip conductor has a portion projecting into the hole. The metal strip conductor of the first winding is electrically connected to the metal strip conductor of the second winding through the holes of the insulative sheets.

Planar transformer

A DC--DC converter including a transformer having a primary winding and a tapped secondary winding; an output filter made up of a filter inductor and a filter capacitor connected in series with one side of the output filter connected to the tap terminal of the secondary winding; a first unidirectional device and a second unidirectional device connected in series with each other and with opposite polarities, there being a common node between them, the first unidirectional device electrically coupled to the first terminal of the secondary winding, the second unidirectional device electrically coupled to the second terminal of the secondary winding, and the output filter electrically coupled to the common node; a first switch connected in series with the primary winding; and a clamping circuit connected between two of the terminals of the secondary winding, wherein the clamping circuit includes a clamping capacitor connected in series with a second switch.

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Malden, MA, United States of America

Fei Ma