The fault phenomena of fluorescent lamps are investigated by observing the operations in the last period of the life cycle. Accordingly, fault detecting and protection circuits are designed.
Before coming to the life-end, the lamps can be started up, but are operated abnormally. A ruddy glow may occur at one end of the cathode filaments and an unstable arc may happen to the lamp. Obviously, the light efficiency becomes relatively low. The arc instability eventually results in a totally damaged fluorescent lamp. It is found that both waveforms of the lamp voltage and the lamp current are asymmetrical and have unequal positive and negative peak values. The asymmetry is more significant for the lamp voltage. In addition, a dc component is present in the lamp voltage. Based on these investigated results, the detection and protection circuits are designed for high-frequency electronic ballasts under dimming operations as well at the rated power. The experiments show that the detection and protection circuits can work effectively.
Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0819104-175459 |
Date | 19 August 2004 |
Creators | Lee, Cheng-Chung |
Contributors | Ching-Ran Lee, none, Hau-Chen Yen, Yong-Nong Chang, Chin-Sien Moo |
Publisher | NSYSU |
Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
Language | Cholon |
Detected Language | English |
Type | text |
Format | application/pdf |
Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0819104-175459 |
Rights | withheld, Copyright information available at source archive |
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