Discharge lamp operation apparatus
US4600862A · kind A · utility
0Cited by
4References
2Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 5, 1984 |
| Grant date | Jul 15, 1986 |
| Priority date | — |
| Expiry date | Oct 5, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/825
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A high-pressure sodium lamp is connected to a d.c. power supply through a ballast, to operate it with a current containing a d.c. component. The relation between the ratio l/d of the inter-electrode distance l (mm) to the inner diameter d (mm) of the arc tube of the high-pressure sodium lamp and the sodium vapor pressure P.sub.Na (kPa) in the arc tube is maintained at P.sub.Na .gtoreq.6.0 (l/d-5.8), thus making it possible to operate the high-pressure sodium lamp with a current containing a d.c. component without causing a significant color separation which otherwise might be the result of cataphoresis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.