Electronic ballast for a high intensity discharge lamp
US7015655B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 2002 |
| Grant date | Mar 21, 2006 |
| Priority date | — |
| Expiry date | May 29, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/05
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electronic ballast for a discharge lamp is capable of dimming the lamp over a wide range, yet minimizing a color temperature deviation. The ballast includes a power converter which converts an input DC voltage into a lamp power for driving the lamp, and a dimmer providing a dimmer command of a varying dimming ratio in order to reduce the lamp power to a greater extent as the dimming ratio decreases. A controller controls the power converter to supply a high frequency AC current to the lamp in response to the dimming ratio decreasing to a predetermined level, and to reduce an RMS value of the high frequency AC current as the dimming ratio decreases past the predetermined level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.