Nowadays, electronics has really flourished with the rapid progress in science and technology. Besides being light and efficient of the products, digitalization and faster speed are also required which make the problem of EMI, electromagnetic interference, become more serious. Newer power supplies using switching technology become smaller and smaller. However, they also produce EMI problems that need to be considered. In this thesis, we only address the conducted EMI.
Generally, the noise is suppressed by adding a filter at the power-line end. Hence, the EMI filter plays an important role to the solution of conducted emission. The particular filter is related to the type of the conducted emission, including common-mode and differential-mode. As a result, it is a great help for an engineer to be able to separate the noise. There are several noise separators in the present days. We propose new separators, which are capable of detect common-mode and differential-mode separately. Our separators are low-cost, easily manufactured and are able to give exact noise readings without adjustment.
Incorporating the known methods of filter design and combing programming measurement the filter design can be made automatic. One approach makes use of the spectrum analyzer, which is considered to be a relatively expensive instrument. We also propose another approach using oscilloscope. The time-domain measurement is performed and transformed into frequency domain using FFT. A realistic design example is shown to give satisfactory results.
Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0619100-164404 |
Date | 19 June 2000 |
Creators | Su, Hsin-Lung |
Contributors | Rhuy-Teh Chung, Fzong-Lin Wu, Wen-Jcng Ho, Ken-Huang Lin, Ching-Pian Huy |
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-0619100-164404 |
Rights | withheld, Copyright information available at source archive |
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