Patent ID: 7141933

Claim:
A negative-impedance gas-discharge lamp load assembly comprising: a plurality of at least 4 lamp loads, where the lamp loads each have a first end and a second end; a first terminal and a second terminal for receiving power from a secondary winding of an inverter transformer for driving the plurality of lamp loads in parallel, wherein a first terminal is operatively coupled to first ends of the lamp loads; and a straight tree of a two-way balancing transformer in a first level and first and second groups of ring balancing transformers in a second level: where the two-way balancing transformer is operatively coupled to the second terminal and is configured to balance current between the first and second rings of ring balancing transformers; where the first group of ring balancing transformers are individually operatively coupled to second ends of at least a first lamp load and a second lamp load and balance currents for the same; and where the second group of ring balancing transformers are individually operatively coupled to second ends of a third lamp load and a fourth lamp load and balance currents for the same.