Starting and operating circuit for arc discharge lamp
US5138235A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 4, 1991 |
| Grant date | Aug 11, 1992 |
| Priority date | — |
| Expiry date | Mar 4, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit for starting and operating a discharge lamp, such as a compact fluorescent lamp, at high frequency from an 60 Hz AC supply. The circuit includes a power supply for generating a DC voltage coupled to a pair of AC input terminals. A DC/AC converter includes an oscillator having a pair of semiconductor switches coupled in parallel with the DC power supply. an oscillator starting circuit is coupled to one of the semiconductor switches and includes a series circuit comprising a resistor, capacitor and threshold element. The input of the oscillator starting circuit is coupled to one of the AC input terminals so as to prevent a momentary flicker in the lamp after the AC supply is removed and the lamp has extinguished. In accordance with another aspect of the invention, the oscillator includes fusible circuit elements which render the oscillator inoperable upon failure of the lamp due to depletion of emissive material on at least one of the lamp electrodes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.