Lamp protection circuit for electronic ballasts
US5635799A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 10, 1996 |
| Grant date | Jun 3, 1997 |
| Priority date | — |
| Expiry date | May 10, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/2855
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electronic ballast has a protection circuit particularly useful for smaller diameter gas discharge lamps including compact fluorescent lamps. The protection circuit prevents lamps from overheating by preventing the ballast from providing sustained output power when the magnitude of the ballast output voltage indicates abnormal lamp operation. The protection circuit has a voltage sensor which develops a voltage that is more negative than the negative DC supply terminal of the inverter so that an inexpensive low-voltage SCR can be used to turn off the inverter. The circuit provides automatic restarting of the ballast after a new lamp has been installed to eliminate the need for toggling the input power to the ballast.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.