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Doesn't coiling cables while passing increasing levels of power through them (which is exactly what's happening with new USB-C PD specs) start giving off more and more heat?

EDIT: Nope! See the replies.



Coiling is only relevant to magnetic fields. These cables generally have the same amount of current passing in opposite directions through different wires, so net zero.


Ah that makes sense! Having current in opposite directions in the two wires in the cable cancels it out. Thanks for explaining.

I guess the warnings about not running loads of current through coiled cables are more to do with heat dissapation then?


No. The amount of heat given off is just going to be I^2R, and coiling the cable doesn't increase R.

If you coil it so tightly that the heat can't get out, that could be problematic, but it is not likely to be a problem with this coiling technique.


Coiled extension cords are definitely a hazard at sufficiently high power, though.


Coiled AC extension cords.




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