Balancing arrangement with reduced amount of balancing transformers

• US 7,990,072 B2
• Filed: 02/02/2009
• Issued: 08/02/2011
• Est. Priority Date: 10/06/2003
• Status: Expired due to Fees

• Current Assignee: Microsemi Corporation (Microchip Technology Incorporated)
• Original Assignee: Microsemi Corporation (Microchip Technology Incorporated)
• Inventors: Jin, Xiaoping
• Primary Examiner(s): Chang; Daniel D
• Application Number:
  US12/363,807
• Publication Number:
  US 20090195178A1
• Time in Patent Office: 911 Days
• Field of Search: 315/282, 315/312, 315/121, 315/255, 315/177, 315/277, 315/130, 315/246
• US Class Current: 315/282
• CPC Class Codes: H05B 41/2822 using specially adapted components in the load circuit, e.g. feed-back transformers, piezoelectric transformers; using specially adapted load circuit configurations

Abstract

A backlighting arrangement constituted of: a driving transformer; at least one balancing transformer; a plurality of luminaires, a first end of each of the plurality of luminaires connected to a high voltage lead of the driving transformer and a second end of each of the plurality of luminaires connected to a unique end of a winding of the at least one balancing transformer, wherein each pair of the luminaires is associated with a particular winding of one of the at least one balancing transformers, and wherein the first end and the second end of each of the luminaires is in physical proximity of the driving transformer and the at least one balancing transformer, the constituent lamps of the luminaires arranged in parallel and generally extending axially away from the proximity of the driving transformer.

Claims

1. A backlighting arrangement comprising:

a driving transformer;

at least one balancing transformer; and

a plurality of luminaires, each of said plurality of luminaires constituted of one of a U-shaped lamp and a pair of linear lamps which are directly serially connected to each other, a first end of each of said plurality of luminaires connected to a high voltage lead of said driving transformer and a second end of each of said plurality of luminaires connected to a unique end of a winding of said at least one balancing transformer,

wherein each pair of said luminaires is associated with a particular winding of one of said at least one balancing transformers, a first luminaire of said pair connected to a first end of said particular winding and a second luminaire of said pair connected to second end of said particular winding, said second end different from said first end, and

wherein said first end and said second end of each of said luminaires is in physical proximity of said driving transformer and said at least one balancing transformer, said constituent lamps of said luminaires arranged in parallel and generally extending axially away from said proximity of said driving transformer.

2. A backlighting arrangement according to claim 1, wherein said plurality of luminaires is constituted of 4 luminaires, a first two of said luminaires connected to each end of a primary winding of a single balancing transformer and a second two of said luminaires connected to each end of a secondary winding of said single balancing transformer.

3. A backlighting arrangement according to claim 1, comprising at least two balancing transformers, wherein said particular winding of said balancing transformers is a primary winding, each of said balancing transformers comprising a secondary winding magnetically coupled to said primary winding, said secondary windings of said balancing transformers serially connected in a closed in-phase loop.

4. A backlighting arrangement according to claim 3, comprising an odd number of luminaires wherein one of said luminaires does not participate in any of said pairs, the second end of the primary winding of the balancing transformer associated with said not participating luminaire connected to a high voltage lead of said driving transformer.

5. A backlighting arrangement according to claim 3, comprising an odd number of luminaires wherein one of said luminaires does not participate in any of said pairs, and wherein said driving transformer exhibits a pair of secondary windings, a first end of each of said secondary windings being connected together, and wherein said high voltage leads of said driving transformer are associated with a second end of each of said secondary windings, the second end of the primary winding of the balancing transformer associated with said not participating luminaire connected to said first end of said secondary windings of said driving transformer.

6. A backlighting arrangement according to claim 3, wherein each of said luminaires is constituted of said pair of serially directly connected linear lamps, and further comprising an additional balancing transformer associated with each of said luminaires, a primary winding of said associated additional balancing transformer connected between said serially directly connected linear lamps, a secondary winding of each of said additional balancing transformers being serially connected in said closed in-phase loop.

7. A backlighting arrangement according to claim 3, wherein a current sensing arrangement is provided within said serially connected closed in-phase loop.

8. A backlighting arrangement according to claim 1, wherein said luminaires are arranged so that adjacent ends of said luminaires exhibit a uniform voltage difference there between.

9. A backlighting arrangement according to claim 1, wherein said driving transformer exhibits a pair of secondary windings, a first end of each of said secondary windings being connected to a common point via a unique sense resistor, and wherein said high voltage leads of said driving transformer are associated with a second end of each of said secondary windings.

10. A backlighting arrangement according to claim 1, wherein said driving transformer exhibits a pair of secondary windings, a first end of each of said secondary windings being connected together, and wherein said high voltage leads of said driving transformer are associated with a second end of each of said secondary windings.

11. A backlighting arrangement comprising:

an alternating current voltage source, comprising a first and a second voltage lead;

at least one balancing transformer; and

a plurality of luminaires, each of said plurality of luminaires constituted of one of a U-shaped lamp and a pair of linear lamps which are directly serially connected to each other, a first end of each of said plurality of luminaires connected to one of said first and second voltage leads and a second end of each of said plurality of luminaires connected to a unique end of a winding of said at least one balancing transformer,

wherein each pair of said luminaires is associated with a particular winding of one of said at least one balancing transformers, a first luminaire of said pair connected to a first end of said particular winding and a second luminaire of said pair connected to second end of said particular winding, said second end different from said first end, and

wherein said first end and said second end of each of said luminaires are generally spatially aligned to define a first plane, said constituent lamps of said luminaires arranged in parallel and generally defining a second plane orthogonal to said first plane.

12. A backlighting arrangement according to claim 11, wherein said plurality of luminaires is constituted of 4 luminaires, a first two of said luminaires connected to each end of a primary winding of a single balancing transformer and a second two of said luminaires connected to each end of a secondary winding of said single balancing transformer.

13. A backlighting arrangement according to claim 11, comprising at least two balancing transformers, wherein said particular winding of said balancing transformers is a primary winding, each of said balancing transformers comprising a secondary winding magnetically coupled to said primary winding, said secondary windings of said balancing transformers serially connected in a closed in-phase loop.

14. A backlighting arrangement according to claim 13, comprising an odd number of luminaires wherein one of said luminaires does not participate in any of said pairs, the second end of the primary winding of the balancing transformer associated with said not participating luminaire connected to one of said first and second voltage leads.

15. A backlighting arrangement according to claim 13, comprising an odd number of luminaires wherein one of said luminaires does not participate in any of said pairs, and wherein said alternating current voltage source comprises a driving transformer exhibiting a pair of secondary windings, a first end of each of said secondary windings being connected together, and wherein said high voltage leads of said driving transformer are associated with a second end of each of said secondary windings, the second end of the primary winding of the balancing transformer associated with said not participating luminaire connected to said first end of said secondary windings of said driving transformer.

16. A backlighting arrangement according to claim 13, wherein each of said luminaires is constituted of said pair of serially directly connected linear lamps, and further comprising an additional balancing transformer associated with each of said luminaires, a primary winding of said associated additional balancing transformer connected between said serially connected linear lamps, a secondary winding of each of said additional balancing transformers being serially connected in said closed in-phase loop.

17. A backlighting arrangement according to claim 13, wherein a current sensing arrangement is provided within said serially connected closed in-phase loop.

18. A backlighting arrangement according to claim 11, wherein said luminaires are arranged so that adjacent ends of said luminaires exhibit a uniform voltage difference there between.

19. A backlighting arrangement according to claim 11, wherein said alternating current voltage source comprises a driving transformer exhibiting a pair of secondary windings, a first end of each of said secondary windings being connected to a common point via a unique sense resistor, and wherein said voltage leads of said driving transformer are associated with a second end of each of said secondary windings.

20. A backlighting arrangement according to claim 11, wherein said alternating current voltage source comprises a driving transformer exhibiting a pair of secondary windings, a first end of each of said secondary windings being connected together, and wherein said voltage leads of said driving transformer are associated with a second end of each of said secondary windings.

21. A method of backlighting comprising:

receiving an alternating current voltage;

providing at least one balancing transformer;

providing a plurality of luminaires, each of said plurality of luminaires constituted of one of a U-shaped lamp and a pair of linear lamps which are directly serially connected to each other;

connecting a first end of each of said provided plurality of luminaires to one polarity of said received alternating current voltage;

connecting a second end of each of said provided plurality of luminaires to a unique end of a winding of said at least one balancing transformer, wherein each pair of said luminaires is associated with a particular winding of one of said at least one balancing transformers, a first luminaire of said pair connected to a first end of said particular winding and a second luminaire of said pair connected to second end of said particular winding, said second end different from said first end; and

spatially arranging said provided luminaires so that said first end and said second end of each of said luminaires generally define a first plane, said constituent lamps of said luminaires generally defining a second plane orthogonal to said first plane.