R. S. Ridley

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A variety of procedures are available to detect parasite eggs or oocysts in feces. This study compared the efficacy of simple flotation, a commercial assay, and various centrifugation techniques and three common flotation solutions. Results indicate that centrifugation consistently recovered more eggs than other methods. Proper technique is critical,(More)
Transformer Design Example Figure 1 shows a simple 1:1 transformer. The transformer uses an ungapped EPC-25 core from TDK, made from PC-44 material. This transformer was designed for use in a 60 W forward converter with 36-60 V input and 12 V output. Figure 2 shows the winding layout, with just a single layer of 18 turns for the primary winding, a layer of(More)
The Sepic Converter The most basic converter that we looked at last month is the buck converter. It is so named because it always steps down, or bucks, the input voltage. The output of the converter is given by: Interchange the input and the output of the buck converter, and you get the second basic converter – the boost. The boost always steps up, hence(More)
For working power supply engineers, the Unitrode handbook is often the standard reference for control analysis. This paper gives a very simple extension to the existing Unitrode models that accounts for the subharmonic oscillation phenomenon seen in current-mode controlled converters. Without needing any comI?lex analysis, the oscillation phenomenon, ramp(More)
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