In article , N_Cook
wrote:

On 13/02/2015 05:59, isw wrote:
I recently came across a YouTube video where a guy rewound a microwave
transformer to make a spot welder.

In talking about it, he stated -- and repeated -- that it was very
important for the secondary winding to have the same "sense" as the
primary -- that is, both windings had to go around the core in the same
direction.

I know that matters if the transformer is handling very asymmetric
waveforms such as in a flyback configuration, but I have never heard
that it matters for plain old 60 Hz. sinusoids.

Does it? Or was the guy just confused?

Isaac


Even using it in reverse, swapping primary and secondary, you will not
get the low volts and high amps for welding.
Did u-tubber just use the core and existing primary and rewind the
secondary secondary with 1 to 2mm diameter wire? should be obvious in
the vide, those sorts of dimensions

That's what he was doing.

Isaac