Patent · US Expired

Balanced power supply circuit for multiple cold-cathode fluorescent lamps

US6104146A · kind A · utility

92Cited by
6References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 12, 1999
Grant dateAug 15, 2000
Priority date
Expiry dateFeb 12, 2019

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02B20/00
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

The present invention provides a CCFL driving circuit having a parallel-arranged transformer system and a feedback loop positioned to sense the current in one of the lamps in the system. Each CCFL in the system is driven by the secondary side an individual transformer. Based on the current sensed in the feedback loop, a controller supplies the appropriate driving voltage to the primary side of the transformers, which in turn powers each CCFL. Since the primary sides of the transformers are arranged in parallel, and since each CCFL is connected at a common node, it is ensured that each transformer receives identical voltage, and the current in each CCFL loop is balanced.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.