Discharge lamp lighting device
US4503359A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 2, 1983 |
| Grant date | Mar 5, 1985 |
| Priority date | — |
| Expiry date | Sep 2, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Disclosed is a discharge lamp lighting device which comprises a series closed-loop circuit including an AC power supply, a ballast having an inductance, and a discharge lamp, and a switch circuit in parallel to the discharge lamp. The switch circuit is turned on when the voltage across the discharge lamp is reduced to zero, and then turned off when the current flowing in the switch reaches a predetermined value. The switch circuit thus repeats its on-off operation every half cycle of the voltage across the discharge lamp. The electromagnetic energy is stored in the inductance of the ballast when the switch circuit is on, and the stored electromagnetic energy is superimposed on the source voltage and applied to the discharge lamp when the switch circuit is turned off, thus reigniting the discharge lamp every half cycle. This makes it possible to light directly a discharge lamp having a lamp voltage approximate to the source voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.