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Registered Member #2099
Joined: Wed Apr 29 2009, 12:22AM
Location: Los Altos, California
Posts: 1714
There are people who say that if a SMPS doesn't get hot, it's unnecessarily expensive.
A SMPS designer I am not, but here's a chart of core loss vs. temperature (at 100 kHz and 1 k gauss) for the F, P, and R materials that 2Spoons referred to. https://www.mag-inc.com/Media/Magnetics/File-Library/Product%20Literature/Ferrite%20Literature/Ferrite-Core-Material-Selection-Guide.pdf?ext=.pdf Sorry, the forum's automatic link feature is having trouble with space characters in the middle of the URL.
We see that material P is formulated for minimum loss at 70 to 80 degrees C, and R for minimum loss at 100 to 110 degrees C.
At work we use a ton of buck converters with outputs like 0.9 volts at 13 amps, with a surface mounted inductor out of a catalog. Recently I was surprised to learn that they run at 2 MHz! Now you have me wanting to look up the inductor part number, and see if its core material and/or air-gappiness is given.
Hint, please, about how you edited pictures into your post. Thanks!
Registered Member #2939
Joined: Fri Jun 25 2010, 04:25AM
Location:
Posts: 615
Ergh! Just had a look at the Arrow site for the first time ever. No wonder you had trouble finding stuff - they must have the worst site layout and part filter I've seen.
Registered Member #2099
Joined: Wed Apr 29 2009, 12:22AM
Location: Los Altos, California
Posts: 1714
Oops, I missed that. Let's try it now.
But it doesn't replace the old way, which has been broken for a few months, to upload images to 4hv server. Readers saw an appropriate-size thumbnail (~ 400px) inline, and could click on if they wanted to see full size image. Just clicked in the dialog at the bottom of composing window, called "Attach file(s) / image(s)". Since the failure, the list of Allowed file types is empty.
The alternative, which you demonstrated, is better than nothing. But doesn't it depend on an outside link, which might not work tomorrow or two years from now? And most users wanting to post need to engage a third party to host the image, and also the thumbnail if they want to do it properly.
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"Upgrading" a DC-DC Converter
