Electronic ballast for operating lamps in parallel
US5563473A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1995 |
| Grant date | Oct 8, 1996 |
| Priority date | — |
| Expiry date | Jun 2, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/05
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electronic ballast for powering at least two rapid start, parallel connected fluorescent lamps. Associated with each lamp is a serially connected choke and capacitor combination. A train of pulses of alternating polarity having a fundamental frequency, which is generated by an inverter, is applied to each serially connected combination. Each combination is characterized by a resonant frequency which is other than an odd harmonic of and at least two times and preferably .sqroot. 5 times greater than the fundamental frequency. Reduction in filament heating, following lamp ignition, is provided through the addition of voltages applied to each filament which are substantially out of phase with each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.