Automatic state tranition controller for a fluorescent lamp
US5652481A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 1996 |
| Grant date | Jul 29, 1997 |
| Priority date | — |
| Expiry date | Mar 15, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B47/185
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A control module and method controls the operation of a fluorescent lamp in a circuit in which the lamp is connected to a ballast and energized by alternating half-cycles of power supplied from an AC power source. The fluorescent lamp has cathodes and a medium which emits light energy when energized into a plasma. A controllable switch conducts half-cycles of AC current through the cathodes and commutates into a non-conductive condition. A sensor supplies sensing signals related to an electrical condition at the cathodes. A state transition controller controls the switch. The state transition controller establishes a power-up, warm-up, ignition and fire operational states and transitions between the states in response to the electrical condition sensed and the time duration of those conditions. The lamp lights more reliably, premature failure of the ballast and cathodes is prevented due to overheating, and the lamp is controlled effectively by input signals in the form of short power interruptions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.