Electronic ballast system
US6262542A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 19, 2000 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | May 19, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electronic ballast for use in illuminating a lamp includes a lamp driving circuit having a pulse-width modulated signal generator, a timing capacitor coupled to the lamp driving circuit, and a power controller. The power controller uses a current sense resistor to detect a current flowing through the lamp and an operational amplifier circuit to compare a signal associated with the detected current to a reference voltage associated with a desired lamp current. Based on the comparison, the power controller provides a correction current to the timing capacitor to control a duty cycle of an output of the pulse-width modulated signal generator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.