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I am trying to fit a umo wire into a ac power transformer. Turns out the jumper wire is just a little too thin. Any practical ideas on how to fatten them?

I considered dipping them into molten solder. Or then i thought maybe this wont work, so i thought heating individual small parts of solder, then attaching the jumper wire end to fatten it, then continuing to do so gradually, until the whole jumper wire end is fattened?

Any ideas? Or is there anyone who has dont this already and succesfully?

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More wires side by side? – Cornelius May 2 '14 at 17:29
Strip twice the length you need, then fold the end over. – Dave Tweed May 2 '14 at 17:31
What's an "umo wire"? – gwideman May 2 '14 at 20:27

For industrial applications, ferrules are commonly used. They are metal sleeves that get crimped onto the ends of wires where connections will be made:

Ferrules (sorry for the big picture!)

Their main purpose is to gather up all the strands of a stranded wire, and give a good, solid connection for use with screw terminals or clamp-style connection points. But, for your purpose, they should add some thickness to the wire.

I don't believe that multiple layers of solder will work, because each subsequent application will reflow all of the solder present, and won't stack up...

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Wow - Digi-Key has almost 1300 different types of these. – tcrosley May 2 '14 at 18:19
@tcrosley Ha! Yes, and they're not exactly cheap :) For the purpose of the original question, a simple, uninsulated ferrule should be fine. No need for insulation, plastic wire guides, or anything fancy... – bitsmack May 2 '14 at 18:58

Another option: Don't. A thin wire in a thick hole means that you're likely trying to use something designed for high currents in a wire that's designed for low currents. Get a wire that's designed for the application, or get a transformer that's sized appropriately for the application!

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