Asymmetric end-of-life protection circuit for fluorescent lamp ballasts
US8564216B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 2, 2011 |
| Grant date | Oct 22, 2013 |
| Priority date | — |
| Expiry date | Dec 16, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/2985
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An asymmetric end-of-life protection circuit with single-point voltage measurement is provided for an electronic ballast having two lamp connection terminals. A grounding circuit includes a capacitor and a first resistor coupled in parallel between a first lamp connection terminal and ground, and is effective to drain the second lamp connection terminal to ground. A lamp voltage detection circuit is coupled between the first lamp connection terminal and ground and measures the lamp voltage from the first lamp connection terminal. A controller is effective to shut down the ballast based on an output signal from the lamp voltage detection circuit being greater than a first predetermined threshold value or less than a second predetermined threshold value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.