Low distortion line dimmer and dimming ballast
US6229271A · kind A · utility
140Cited by
11References
19Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 24, 2000 |
| Grant date | May 8, 2001 |
| Priority date | — |
| Expiry date | Feb 24, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A line dimmer has a limited maximum firing angle to limit a total harmonic distortion within a powering signal. A dimming ballast generates a pulse width modulated signal based on a firing angle of the powering signal, generates a dimming command signal based on the pulse width modulated signal, and dims a lamp based on the dimming command signal. The maximum firing angle may be limited to 30 degrees, 25 degrees, or 20 degrees, for example, to limit a resulting total harmonic distortion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.