Solid state ballast for gaseous discharge lamps
US4641061A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 22, 1985 |
| Grant date | Feb 3, 1987 |
| Priority date | — |
| Expiry date | Apr 22, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A solid state ballast for starting and operating a plurality of fluorescent lamps comprises a plurality of parallel connected, series LC circuits each coupled by a capacitor to a lamp so that voltage existing across the series capacitors is applied across the lamps and driven by an inverter at a DC power source voltage and at a selected frequency high enough to develop a lamp starting voltage but substantially below their resonant frequency. After starting the resonant frequency of the LC circuits is reduced substantially below the selected frequency by the added capacitive reactances of the coupling capacitors whereby the destructive high voltage at the upper and lower resonances is avoided and the independent selection of the values of L and C and the coupling capacitors to control starting voltage and conduction after starting at the selected frequency is provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.