Fluorescent lamp controllers
US5111118A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 1991 |
| Grant date | May 5, 1992 |
| Priority date | — |
| Expiry date | Aug 12, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A controller operates in pre-ignition and ignition phases to obtain stable and reliable control of operation of a half-bridge DC-AC converter in a frequency range which is offset from a resonant frequency of an output circuit which includes a transformer and capacitors and which couples the converter to a fluorescent lamp load. The converter is supplied with a DC voltage from a switched-mode DC-DC supply of a pre-conditioner circuit which responds to a full-wave rectified AC voltage and which is supplied with pulse-width modulated gating pulses from the controller, preferably at a frequency which is the same as that of the converter. The controller monitors signals from the output circuit and pre-conditioner circuits and exercises control to reliable starting and highly efficient lamp operation and to obtain an in-phase proportional relationship of input voltage and current wave forms.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.