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Please use this identifier to cite or link to this item:
http://hdl.handle.net/1783.1/399
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| Title: | Phase-controlled dimmable ballast |
| Authors: | Ki, Wing-Hung
Mok, Philip
Sin, Johnny K. O. |
| Keywords: | Phase-controlled dimmable ballast
Fluorescent lamps
Switching frequency |
| Issue Date: | 9-Jan-2001 |
| Citation: | US Patent 6,172,466. Washington, DC: US Patent and Trademark Office, 2001. |
| Abstract: | A method and apparatus are disclosed for the dimming control of a fluorescent lamp driven by an electronic ballast. A small portion (eg less than 15°) of the phase of the input supply voltage is removed, and the precise amount of the phase removed is used to generate a switching signal that controls the switching frequency of the electronic ballast and hence the light power output. The switching frequency is generated by producing pulses of a width proportional to the amount of phase removed, integrating the pulses to produce a voltage proportional to the phase removed, converting that voltage to a current that varies with a frequency depending on the voltage, and using that varying current to generate the switching frequency. |
| Rights: | This patent is also available at HKUST Technology Transfer Center Patent Search at <http://patentsearch.ttc.ust.hk/ListPatentsDetail.asp?id=118> |
| URI: | http://hdl.handle.net/1783.1/399 |
| Appears in Collections: | ECE Patents
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Files in This Item:
| File |
Description |
Size | Format |
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| US6172466.pdf | | 443Kb | Adobe PDF | View/Open |
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