Self-dimming electronic ballast
US5396155A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 1994 |
| Grant date | Mar 7, 1995 |
| Priority date | — |
| Expiry date | Jun 28, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A self-dimming electronic ballast for a gas discharge lamp includes a converter having an unregulated boost circuit coupled to a variable frequency inverter having a series resonant, parallel loaded output. The inverter includes a variable frequency driver circuit having a timing circuit for determining the frequency of the driver. A transistor in the timing circuit operates as an inverting amplifer and is controlled by a signal proportional to the voltage of the AC line. The frequency of the inverter increases with decreasing voltage on the AC line. The ballast can be on the same circuit as incandescent lamps and powered by a triac or variac dimmer for dimming both the incandescent and gas discharge lamps.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.