Inverter transformer

• US 6,650,218 B1
• Filed: 05/31/2002
• Issued: 11/18/2003
• Est. Priority Date: 01/20/2000
• Status: Active Grant

• Current Assignee: Lear Corporation, Sumida Corporation
• Original Assignee: Sumida Corporation, Sumika Technology Company Limited (Sumitomo Chemical Company Limited)
• Inventors: Fushimi, Tadayuki
• Primary Examiner(s): Lee, Wilson
• Application Number:
  US10/158,198
• Publication Number:
  US 20030222746A1
• Time in Patent Office: 536 Days
• Field of Search: 336/82, 336/83, 336/90, 336/92, 336/98, 336/186, 336/192, 336/198, 336/199, 336/213, 336/214, 336/223, 315/276, 315/224, 315/246, 315/248
• US Class Current: 336/178
• CPC Class Codes: H01F 38/10 Ballasts, e.g. for discharge lamps

Abstract

An inverter transformer is formed of first and second cores arranged to face each other to form a closed magnetic circuit. The first core has a central leg, an outer perimeter wall, and a partition between the central leg and the outer perimeter wall so that a first groove is formed between the central leg and the partition and a second groove is formed between the partition and the outer perimeter wall concentrically with and outside the first groove. A primary winding is disposed in the second groove, and a secondary winding is disposed in the first groove so that the primary and secondary windings are arranged in the same plane.

Claims

1. An inverter transformer, comprising:

first and second cores arranged to face each other to form a closed magnetic circuit, said first core having a central leg, an outer perimeter wall, and a partition wall between the central leg and the outer perimeter wall so that a first groove is formed between the central leg and the partition wall and a second groove is formed between the partition wall and the outer perimeter wall concentrically with and outside the first groove,

a primary winding disposed in the second groove between the partition wall and the outer perimeter wall, and

a secondary winding disposed in the first groove between the central leg and the partition wall so that the primary and secondary windings are arranged in a same plane.

2. An inverter transformer according to claim 1, wherein said first core is a groove formation core, and the second core is a plate-shaped core facing the groove formation core.

3. An inverter transformer according to claim 2, further comprising terminal plates made of an electrically insulating material and disposed on two side surfaces of the plate-shaped core.

4. An inverter transformer according to claim 3, wherein the outer perimeter wall of the groove formation core is tightly joined to the plate-shaped core and the terminal plates to seal an inside of the groove formation core.

5. An inverter transformer according to claim 2, wherein a gap is formed from the plate-shaped core to the central leg and the partition wall of the groove formation core.

6. An inverter transformer according to claim 1, wherein said secondary winding includes a main winding arranged in the first groove between the central leg and the partition wall, and a supplemental winding arranged concentrically with the main winding and disposed in the second groove between the partition wall and the outer perimeter wall, said primary winding being arranged concentrically with the main and supplemental windings and disposed in the second groove outside the supplemental winding.

7. An inverter transformer comprising:

first and second cores arranged to face each other to form a closed magnetic circuit, said first core having a central leg, an outer perimeter wall, and a partition between the central leg and the outer perimeter wall so that a first groove is formed between the central leg and the partition and a second grove is formed between the partition and the outer perimeter wall concentrically with the first groove,

a primary winding disposed in the second groove in a bobbin-less state, and

a secondary winding disposed in the first groove so that the primary and secondary windings are arranged in a same plane, said secondary winding having a bobbin, a main winding wound around the bobbin and disposed in the first groove between the central leg and the partition, and a supplemental winding arranged concentrically with the main winding and disposed in a bobbin-less state in the second groove between the partition and the outer perimeter wall, said primary winding being arranged concentrically with the main winding and the supplemental winding outside the supplemental winding.

8. An inverter transformer according to claim 7, wherein the bobbin is provided integrally with a terminal plate.

9. An inverter transformer according to claim 8, wherein the terminal plate is disposed between the first and second cores.