Electronic ballast with lamp run-up current regulation
US6577078B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 26, 2001 |
| Grant date | Jun 10, 2003 |
| Priority date | — |
| Expiry date | Sep 26, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electronic ballast with lamp run-up current regulation. In one aspect, the electronic ballast comprises an input stage coupled to an AC source, the input stage converting an AC voltage to a direct current bus voltage, an output stage having inputs coupled to the bus voltage and outputs connected to a lamp, the output stage providing (i) power to the lamp so as to produce a lamp voltage and lamp current in a steady state mode of operation, and (ii) a lamp run-up current to the lamp during a run-up phase of the operation of the lamp, and a current regulation circuit for regulating the lamp run-up current so that the lamp run-up current exceeds a steady state lamp current value, and increases if either the bus voltage increases or the lamp voltage decreases. The output circuit comprises a main high-frequency switching inductor through which an inductor current flows wherein the lamp current is based upon the inductor current. In one embodiment, the current regulating circuitry further includes current limiting circuitry for limiting the lamp run-up-current to a predetermined value. In another embodiment, the current regulating circuitry further comprises a feedback circuit that adj…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.