Build a Microwave Transformer Homemade Stick/Arc Welder


Step 7: Test

Picture of Test
Get out yer voltmeter:

Here's the test to make sure the secondaries are both pushing the same direction.
Our two secondaries in series produce 38volts AC with no load. That seems about right.
If they'd phased wrong it could have been fixed by reversing the wiring to any winding.

Where Tim says "out of phase" in the video, he means "in phase". That is, the center tap should be less than the outer two leads, and if things weren't that way, the transformers would be fighting each other, or phased wrong.

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dan7 years ago
referring to your 'one hand behind the back' electrical safety position - for high voltage work you can't just put either hand behind your back - it must be the LEFT hand behind your back. the reason is that if you are prodding at some high voltage gear with your right hand and get zapped - the primary current flow is the shortest path to ground: through your right arm, down your torso on the right side, down your legs and into the ground. now if you use your left hand instead - then unfortunately your heart is in your left side torso and is now part of the predominant current path. high voltage electrical work is unfortunately not a good career choice for lefties. now, as shown (with either hand behind back) it is usually ok for 120vac work, because if your shoes are dry and have decent rubber soles then 120vac isn't enough to go through that.
Your heart is in the CENTER of your chest and has only a small protrusion to the left. All your talk up about the dangers of putting one hand behind the back vs another are all hoo-nanny.

Back in the dark ages I worked a lot with some very dangerous equipment. We were taught to work with one hand in your pocket or behind your back. The problem was not current thru you shoes (electrical safety shoes were always used), but current from hand to hand with your heart in between. A couple times I had terrible shocks...one bad enough to leave a bad burn on my hand. Good technique meant survival. Always remember things break...a safe place to touch today may really get your attention tomorrow.

jules155 years ago
So, you wire the transformers in this so they step down the voltage? Because you want a lot of amps?
msw1005 years ago
Surely DC would be better
skuitarman6 years ago
what if you have more windings on one transformer then you have on the other, will it still work
I'm only getting 11 volts per transformer. I've wound them nice and tight, tighter than in your pictures, with 10 gauge wire. It must be that the transformers I have are smaller. Is 22v an acceptable voltage level for arc welding?