Preheat control device for modulating voltage of gas-discharge lamp
US7557522B2 · kind B2 · utility
2Cited by
6References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 1, 2007 |
| Grant date | Jul 7, 2009 |
| Priority date | — |
| Expiry date | Mar 1, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/3927
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A preheat control device for modulating the voltage of a gas-discharge lamp is disclosed, which comprises: a pulse-width modulation (PWM) circuit, for controlling the voltage of the gas-discharge lamp while it is operating at a preheat state; a pulse frequency modulation (PFM) circuit, for controlling the frequency of the gas-discharge lamp while it is operating at a steady state so as to stabilize the current flowing through the lamp; and a timing unit, for determining a preheat period of the gas-discharge lamp.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.