Fluorescent lamps with current-mode driver control
US5719474A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 14, 1996 |
| Grant date | Feb 17, 1998 |
| Priority date | — |
| Expiry date | Jun 14, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A system wherein light from a fluorescent lamp is dimmed by modulating the pulse-width of current pulses. A current-command signal is applied to a lamp driver in response to a voltage-level corresponding to a given, selectable level of desired lamp brightness. The lamp driver operates as a flyback AC power source that advantageously uses a FET switch to decouple the lamp and a resonant bridge, with the current-sampling process. The circuit samples only the inductor current while the FET switch is active. Because the sample is decoupled from the lamp and bridge, this sampling provides particularly tight control of the regulation process needed to control the incoming noise and transients that affect the power supplied to the lamps. The lamp driver a can also operate as a synchronously-driven resonant forward converter that senses the current actually supplied to the lamp and responds to changes in the fluorescent lamp's condition since the lamp is coupled to the circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.