Digital controlled electronic ballast with piezoelectric transformer
US6509699B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jun 12, 2001 |
| Grant date | Jan 21, 2003 |
| Priority date | — |
| Expiry date | Jun 12, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/2822
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A digitally controlled electronic ballast with a piezoelectric transformer automatically controls the brightness of a lamp in a digital frequency modulation manner. The ballast power a rectifier for rectifying an input low-frequency AC voltage to obtain a DC voltage, a power factor improving circuit for maintaining the level of the DC voltage output from the rectifier constant, an inverter for performing a switching operation, a resonance circuit for transferring a high-frequency AC voltage output from the inverter to the lamp. The resonance circuit includes a coil and a high-power piezoelectric transformer. A digital controller is provided for modulating a frequency controlling a switching period of the inverter when the lamp is turned off/off. The piezoelectric transformer is made of a composition expressed byPb1-aSra[(Ni½W½)b(Mn⅓Nb⅔)c(Zr1-xTix)1-b-c]O3+kPbO.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.