Low voltage ballast circuit for a high brightness discharge light source
US5317237A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 24, 1992 |
| Grant date | May 31, 1994 |
| Priority date | — |
| Expiry date | Nov 24, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A low voltage DC input ballast circuit for a discharge lamp particularly suitable for a central lighting system includes an input filter stage which feeds into a first boost converter circuit controlled by way of a pulse width modulator device. The first boost converter provides warm-up and steady state run signals to the lamp in a voltage fed manner over a coupling circuit using components which are reduced in size relative to conventional discharge ballast circuits. Control circuitry provides various monitoring functions, an example of which is that, in the event of a low input voltage, the lamp will operate in a dimmed or faded manner rather than maintain lumen output by drawing additional current. A second boost converter circuit is associated with a starter circuit arrangement and operates such that starting pulses can be generated and repeated if necessary in a very rapid manner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.