Discharge-lamp lighting circuit
US6175190A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 9, 2000 |
| Grant date | Jan 16, 2001 |
| Priority date | — |
| Expiry date | Mar 9, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A discharge-lamp lighting circuit 1 has a DC-AC converter that incorporates a full bridge circuit consisting of a plurality of pairs of switching devices. The discharge-lamp lighting circuit incorporates an anomaly detector for detecting an anomalous state of the lighting circuit, and a current detector for detecting whether or not an electric current flows in the full bridge circuit in a state where the operation of the lighting circuit is stopped owing to detection of an anomalous state of the lighting circuit by the anomaly detector. The discharge-lamp lighting circuit also includes a device-stage determining unit structured such that when a current has been detected by the current detector, a pair of switching devices, of the switching devices connecting the full bridge circuit and disposed in the higher stage, are switched on. Another pair of the switching devices, disposed in the lower stage are switched off. The discharge-lamp lighting circuit thus prevents generation of a short circuit current owing to an anomalous state of a switching device of the plurality of pairs of switching devices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.