US 7,119,648 B1Granted

Coaxial push pull transformers for power converters and like circuits

OwnerEdward Herbertinventor

Life of this patent

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Abstract

A coaxial push pull transformer is an improved matrix transformer. A number of magnetic cores each contain a pre-wired secondary circuit. The secondary windings are tubular and extend through the core, and the ends of the tubular secondary windings are terminated to make connections to a secondary circuit, such as rectifiers. The cores are placed end to end with the tubular secondary windings aligned and the primary winding is then threaded through all of the cores, so that it is coaxial with the secondary windings when installed, for very low leakage inductance. In the design of the coaxial push pull transformer, care is taken to arrange the terminations of the transformer such that each termination is paired with another termination having a counter-flowing current, to cancel part of the field caused by the flowing currents so as to reduce the overall inductance of the terminals and interconnections. To keep the interconnections to the associated circuitry as short as possible, the associated circuitry may be on circuit boards sandwiched between the transformer cores and directly connected to its terminations.

Claims9

Dependent claims

A coaxial push-pull transformer comprising

a plurality of coaxial push pull modules,
the coaxial push-pull modules comprising
at least a first magnetic core having a through hole therein,
a first tubular secondary windings extending through the through hole in the at least a first magnetic core,
the first tubular secondary winding being a first half of a push pull secondary winding,
a second tubular secondary windings extending through the through hole in the at least a first magnetic core,
the second tubular secondary winding being a second half of a push pull secondary winding,
means for terminating the first and second tubular secondary windings for connection to an electrical circuit,
means for insulating the first tubular secondary winding from the second tubular secondary winding and for insulating the first and second tubular secondary windings from the at least a first magnetic core,
the plurality of coaxial push-pull modules being arranged and disposed so that the first and second tubular secondary windings are aligned from one coaxial push-pull module to the next,
a first primary winding passing through the first tubular secondary windings of the plurality of coaxial push pull modules such that the first tubular secondary windings surround the first primary winding coaxially,
a second primary winding passing through the second tubular secondary windings of the plurality of coaxial push pull modules such that the second tubular secondary windings surround the second primary winding coaxially, and
means for terminating the first and second primary windings for connection to an electrical circuit.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/904,371Filed 6 Nov 2004 · continuation in part
Priority: 3 Apr 2003
Granted: 10 Oct 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H01F 27/027
Casings: specially adapted for combination of signal type inductors or transformers with electronic circuits, e.g. mounting on printed circuit boards
H01F 30/06
Fixed transformers not covered by group H01F19/00: characterised by the structure
H01F 27/292
Terminals; Tapping arrangements for signal inductances: surface mounted devices
H01F 2017/065
With core substantially closed in itself, e.g. toroid: core mounted around conductor to absorb noise, e.g. EMI filter

Family

Application60/460,333Us provisional application · filed 3 Apr 2003
Application60/473,075Us provisional application · filed 23 May 2003
Application60/479,706Us provisional application · filed 19 Jun 2003
Application10/708,846Parent of this continuation-in-part · filed 27 Mar 2004
Application10/709,484Parent of this continuation-in-part · filed 8 May 2004
US 6,979,982 B2Parent of this continuation-in-part · filed 27 Dec 2005
US 7,023,317 B1Parent of this continuation-in-part
US 2004/0232899 A1Published application
US 7,119,648 B1This patent

From the US filing history. Foreign family members aren’t listed.