Hey! in this instructable i will be detailing the steps involved in modifying a microwave oven transformer for high current lower voltage use which shall be achieved by removing the transformers original secondary windings and replacing it with thicker ones of your own. Now the thing to take into mind before you do this is what kind of power you want out of it.
Examples, if you use thicker wire and less of it you will get higher current but lower voltage, if you use thick wire (not as thick) and a few more turns of it you will get high current and slightly higher voltage. or if you keep the original windings you will get one to two thousand volts at one to two amps.
Now to jump right in here's what you will need!
1) A microwave oven transformer
2) An angle grinder or if you don't one and your very keen.. a hacksaw.
3) 1-5 Gauge insulated copper wire.
4) A grounded 3 pin wall plug
Onto the next step!
Examples, if you use thicker wire and less of it you will get higher current but lower voltage, if you use thick wire (not as thick) and a few more turns of it you will get high current and slightly higher voltage. or if you keep the original windings you will get one to two thousand volts at one to two amps.
Now to jump right in here's what you will need!
1) A microwave oven transformer
2) An angle grinder or if you don't one and your very keen.. a hacksaw.
3) 1-5 Gauge insulated copper wire.
4) A grounded 3 pin wall plug
Onto the next step!
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Signing UpStep 1: Removing the secondary windings
Now for the fun part! (not really it kind of sucks)
Step 1) Take you microwave oven transformer and secure it tightly into a vice or onto a solid bench with clamps. Then plug in your angle grinder or pick up your hacksaw (with proper safety gear of course)
Step 2) Cut away the secondary windings, the large amount of thinner wire. and use whatever means necessary to just remove all of the secondary windings.
Step 3) there will be a small length of usually red wire in the middle below where the primary was this is the filament windings, remove these as well. then there is the magnetic shunts, you can also remove these, just tapping them out with a flat head screw driver will work. once all this is removed leaving only the primary left,continue to the next page!
also pictured below is what you should have, but in the pictures I have not yet removed the shunts. (the primary connections are on the opposite side.)
Step 1) Take you microwave oven transformer and secure it tightly into a vice or onto a solid bench with clamps. Then plug in your angle grinder or pick up your hacksaw (with proper safety gear of course)
Step 2) Cut away the secondary windings, the large amount of thinner wire. and use whatever means necessary to just remove all of the secondary windings.
Step 3) there will be a small length of usually red wire in the middle below where the primary was this is the filament windings, remove these as well. then there is the magnetic shunts, you can also remove these, just tapping them out with a flat head screw driver will work. once all this is removed leaving only the primary left,continue to the next page!
also pictured below is what you should have, but in the pictures I have not yet removed the shunts. (the primary connections are on the opposite side.)
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So to summarise, no. Try looking into neon sign transformers. Though to be honest, with respect, a tesla coil may be a little beyond your (safe) reach, given your question.
does that work (heating of nails and screwdrivers) if the secondary was left at 2000v?
if not then why? the same input power is consumed....
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there is no metal fueling, as ive used tungsten electrodes and copper, and they both hold up pretty well
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Some time ago I was excited with the possibility of constructing a spot welder, but here in my city there is no way to get an used microwave transformer: nobody throws away something as that.
Then I tried with my 220-volt electric welder, but I could hardly weak solder some iron wires of 2 mm, even though I was a good time trying.
Today I decided to uncover my welding machine, and found that in the secondary winding there is no place to put even a loop of thin wire. But in the primary, yes!
I think I can easily add several turns of thick wire, by way of a "bis" secondary winding. Now come the doubts, and related questions: whether the primary winding has 248 turns (more or less, it is what I could count), and get 220 volts, it is assumed that each round of "my" coil will produce 220 / 248 = 0,887 volts. What for me? Put only one or two turns, or try to reach five or six? A more laps, more volts but less amps. I suppose that losses play an important role in the case of small voltages, and who knows what is best.
Maybe you has an answer and save me the work of trial and error, which can become very tedious. Thanks in advance!
Question though, i may be misunderstanding here but you want to make another welder out of your welding machine???
if its not doing it for you could just take out its secondary entirely and put in a new one. the more turns of wire is better for a stick welder. but if your making a spot welder the few turns of really heavy gauge wire is best so as to obtain as much current as possible..
But to answer your actual question, you want if for spot welding yes? go for the biggest wire and just put in whatever amount of turns will fit.
I intend to add an additional secondary winding to my welder, without affecting the present one. I noted that around primary winding there is enough room to do it.
But I don't knok how many turns I must add. For your response, I think I must add 5 or 6 if I can reach them.
If the diameter of the cable, including insulation, is 11 mm, that would allow me to barely 3 turns, a little tight. Maybe I can use a cable not so thick, say, 8 mm, but this will limit the amperage output.
used some 200 amp jumper cable which is like 9-10 mm and can handle the high amperage in excess of 800 amps for a short time. tried and tested lol