US Patent 7271548 Multi-lamp drivers and transformers thereof

A multi-lamp driver driving first and second lamps and comprising a driving circuit and a transformer. The transformer comprises a winding rack, a magnetic core, two primary winding sets, and two secondary winding sets. One portion of the magnetic core is inserted into the winding rack. The two primary winding sets are wound around the winding rack and receive low-voltage signals from the driving circuit. The two secondary winding sets are wound around the winding rack, and two high-voltage signals are induced to respectively drive the first and second lamps. The primary winding sets have substantially the same number of windings, and the secondary winding sets have substantially the same number of windings.