Rewinding burnt choke coil

[momaka]

Re: Rewinding burnt choke coil

I believe we are discussing an output inductor, which would have a powdered iron core, not a ferrite core. That powdered iron cores can lose their magnetic properties over time by being run too hot is not news. Here's Micrometals' webpage on the topic.

Hmmm. Good point!

Thanks for posting that link - I learned a lot of new things from it today.

So according to that article, increasing the number of turns decreases the core loss?... at least in the last example they showed with the APFC coil.
- Very interesting!

I'll probably read it a few more times just to make sure I didn't miss something. We did some simple boost and buck regulator calculations back in one of our classes in university, but I've forgotten a large part of that. I don't think we got anywhere near as deep as core material or anything like that. Mostly it was just calculating the inductance for the coil needed based on current and voltage requirements and whatnot.

[PeteS in CA]

Re: Rewinding burnt choke coil

Hmmm. Good point!

Thanks for posting that link - I learned a lot of new things from it today.

So according to that article, increasing the number of turns decreases the core loss?... at least in the last example they showed with the APFC coil.
- Very interesting!

I'll probably read it a few more times just to make sure I didn't miss something. We did some simple boost and buck regulator calculations back in one of our classes in university, but I've forgotten a large part of that. I don't think we got anywhere near as deep as core material or anything like that. Mostly it was just calculating the inductance for the coil needed based on current and voltage requirements and whatnot.

That article's been on Micrometals' website for as long as I can remember. No author is given, but I suspect the/an author may have been Dale Nichol, an applications engineer there for many years. Before Micrometals Dale was the magnetics designer-guru at Boschert back in the late 70s and early 80s.