Ballast control circuit
US7436127B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 2006 |
| Grant date | Oct 14, 2008 |
| Priority date | — |
| Expiry date | Jan 25, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/298
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A ballast control circuit having a bridge driver for driving a transistor bridge of a ballast circuit coupled to a resonant ballast output stage including a lamp, the ballast control circuit comprising a circuit for setting a minimum oscillation frequency and a voltage controlled oscillation circuit having a first input, wherein as a voltage at the first input increases, modes of the circuit change from a preheat mode where the frequency of oscillation moves from a first frequency to a lower preheat frequency and continues at a substantially constant preheat frequency for a set duration of preheat time, to an ignition mode where the frequency moves lower towards a resonance frequency of the ballast output stage until the lamp ignites, and to a run mode where the frequency stops decreasing and stays at the minimum set frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.