Circuit configuration to operate a gas discharge lamp
US6747423B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 26, 2002 |
| Grant date | Jun 8, 2004 |
| Priority date | — |
| Expiry date | Dec 18, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/2988
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a circuit configuration to operate a gas discharge lamp (LA) the lamp (LA) is arranged in a full bridge circuit. A control circuit in normal operation actuates the four switches (S1-S4) in such a way that it changes over with a first frequency (f1) alternately between a first and a second state (T1, T2), whereby in the first state (T1) the two switches (S2, S3) of a first bridge diagonal are opened, one switch (S1) of the second bridge diagonal is closed and the other switch (S4) with a second frequency (f2), which is higher than the first frequency (f1), is alternately opened and closed. In the second state (T2) the four switches (S1-S4) are actuated in such a way that the lamp (LA) is pole reversed. In a start phase (TS) on the contrary the switch connected to the DC voltage source (S4) of a half-bridge is opened, the second switch (S3) of this half-bridge is closed, and the two switches (S1, S2) of the other half-bridge are with a third frequency (f3) alternately opened and closed. As a result reliable lamp starting is rendered possible and at the same time the generation of high-frequent alternating fields in normal operation is reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.