Constant wattage electric ballast circuit for lamp
US6011363A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 2, 1998 |
| Grant date | Jan 4, 2000 |
| Priority date | — |
| Expiry date | Feb 2, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/18
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A constant wattage electronic ballast circuit for lamp comprises a circuit for producing a voltage feedback signal substantially proportional to voltage of the lamp. A diode function generator processes the voltage feedback signal so as to produce a processed signal which, within sequential bands of lamp voltage, varies less for a specified variation of lamp voltage in a higher voltage band than in a lower voltage band. A circuit produces a current feedback signal substantially proportional to current in the lamp. A circuit for controlling lamp current comprises a circuit for summing the processed signal with the current feedback signal to create a summed signal, and a circuit for adjusting lamp current in response to the difference between the summed signal and a reference signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.