US 2006/0220593 A1 · Nested balancing topology for balancing current among multiple lamps

Abstract

An apparatus and methods for balancing current in multiple negative impedance gas discharge lamp loads. Embodiments advantageously include balancing transformer configurations that are relatively cost-effective, reliable, and efficient. Embodiments include configurations that are applicable to an unrestrained number of gas discharge tubes, such as cold cathode fluorescent lamps. The balancing transformer configuration techniques permit a relatively small number of power inverters, such as one power inverter, to power multiple paralleled lamps or paralleled groups of lamps with balancing transformers coupling the lamps or groups of lamps in a zigzag topology. One embodiment of a balancing transformer includes a safety winding which can be used to protect the balancing transformer in the event of a lamp failure and can be used to provide an indication of a failed lamp.

Claims20

Dependent claims

A multi-lamp assembly comprising:

N lamp groups, wherein N is at least three and each lamp group comprises at least two lamps arranged in a lamp subassembly that is coupled between two group ends;
and
at least N−1 outer-level balancing transformers, wherein each outer-level balancing transformer comprises two balance windings configured for coupling to two different lamp groups to balance current between the two different lamp groups and the N−1 outer-level balancing transformers are respectively coupled to N−1 partially overlapping sets of two lamp groups in a zigzag configuration such that each lamp group is coupled to at least one outer-level balancing transformer and each group end of at least N−2 lamp groups is coupled to an outer-level balancing transformer.

Dependencies are inferred from the claim text.

Nested balancing topology for balancing current among multiple lamps

Life of this patent

Nested balancing topology for balancing current among multiple lamps

Life of this patent

Abstract

Claims20