Discharge lamp ballast with detection of abnormal discharge outside the arc tube
US7482762B2 · kind B2 · utility
1Cited by
6References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 22, 2004 |
| Grant date | Jan 27, 2009 |
| Priority date | — |
| Expiry date | Jul 8, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/05
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A discharge lamp ballast is designed to limit or interrupt its AC output power to the discharge lamp upon occurrence of an abnormal discharge outside of an arc tube. A detector is included to examine a lamp voltage once in each of the positive and negative half-cycles or in each one complete cycle of the AC output power, and identifies the abnormal discharge when there is a particular change in the monitored lamp voltage. The particular change may be defined by a single logic or by combination of several logics each designed to represent specific characteristic for the abnormal discharges of several types.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.