Electronic ballast for one or more lamps
US6281641A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 1, 2000 |
| Grant date | Aug 28, 2001 |
| Priority date | — |
| Expiry date | May 1, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electronic ballast apparatus for powering one or more gas discharge lamps includes an inverter that is controlled by an inverter control circuit. The inverter control circuit adjusts certain ballast operating characteristics in order to operate the lamps under nearly the same operating conditions irrespective of how many lamps are connected to the ballast. The inverter control circuit includes a lamp quantity sensor, a regulator circuit and an end-of-lamp-life sensor. The lamp quantity sensor provides a lamp quantity signal that indicates how many lamps are connected to the ballast. The regulator circuit includes a reference adjustment circuit that receives the lamp quantity signal and provides a scaled reference signal to a reference terminal of an error amplifier. The error amplifier also has a feedback terminal that receives a signal that is proportional to the power delivered by the inverter to the lamps. The regulator circuit provides a signal to an inverter power control circuit to ensure that the total power delivered by the inverter to the lamps is proportional to the number of lamps connected to the ballast. The lamp quantity signal is also used to adjust the operation …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.