Discharge lamp ballast having an auto-transformer for high voltage detection
US8207680B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 25, 2009 |
| Grant date | Jun 26, 2012 |
| Priority date | — |
| Expiry date | Aug 23, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A lamp ballast is provided requiring less size and cost for powering a discharge lamp. An inverter circuit converts a DC voltage from a DC power source into a voltage having a determined frequency, and supplies the converted voltage to the discharge lamp inserted between a pair of output ends of the inverter. A resonant circuit includes an auto-transformer and a resonant capacitor, and supplies an output voltage corresponding to a frequency of the rectangular wave voltage of the power supply circuit to the discharge lamp. A voltage detection circuit detects an output voltage of the resonant circuit based on a potential of the resonant capacitor. A control circuit has a startup control mode to set the frequency of the rectangular wave voltage based on the detected voltage from the voltage detection circuit, wherein the output voltage of the resonant circuit exceeds a starting voltage of the discharge lamp.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.