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Re wiring the secondary transformer I could not give it 20 turns. I ran out of space.? Answered

I am trying to build a welder from microwave transfomers. I started using 10 gage solid wire but I could not fit 20 turns as suggested. If I use the stranded wire will I be able to fit the 20 turns? Do bigger transformers come with larger holes or they are the same size? Any suggestions and/or answers are appreciated.

Tags:Welder

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lemonieBest Answer (author)2009-08-23

Well, you either use thinner wire or find a bigger core. I wouldn't advise stranded because you've got less metal-density. Larger transformers are just that - yes you'll have more space. L

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alister357 (author)2010-02-21

to get more amps pout  1 winding of very  thick wire on it

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steveastrouk (author)2009-08-23

How many turns COULD you fit ? 18 ? 19 ? Steve

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taino1 (author)steveastrouk2009-08-24

today I tested the first transformer and it gave me a reading of 13.6 volts. If I build another transformer with 27 turns and connect the two in series will I get 40 volts? and if so, can I used them for the welder?

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steveastrouk (author)taino12009-08-24

You need the heavy gauge wire to get the current you need. What voltage do you want from the welder, how many turns did you manage to get on ? In theory, you can series connect the windings, but if you can only get less than 1/2 the turns you need on your first transformer, I'm afraid I have to say the transformer is too small.

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taino1 (author)steveastrouk2009-08-25

Thanks steve, I appreciate your input. I need 20v in each transformer. I managed to get 13 1/2 turns with the 10 guage solid wire. I took a reading of 13.6 volts. I guess a bigger transformer will do.

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steveastrouk (author)taino12009-08-25

Happy to help. It can be frustrating as hell having too little space on a transfomer !! Been there, got the T shirt. Look at the transformers original power rating, you can't get more POWER from the thing than that. Sure, you can mess around with the current/volts, but you won't beat the power rating. So, what power did the original design supply do you reckon ?

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taino1 (author)steveastrouk2009-08-26

I am not sure but it could have been 700w max. I finished the second transformer and it fitted 17 turns. When I plugged them together I got 30v from the secondaries and the 120v from the primaries. Do you think that is enought to weld with 1/16 rod? Or should I make another transformer with more turns? Thanks again.

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steveastrouk (author)taino12009-08-26

Give it a go. I wouldn't try for more volts, or you will have a poor welder. You need the current, not the volts. Steve

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taino1 (author)steveastrouk2009-08-26

It is all set up to give it go. I turned it on for a few minutes and checked for heat from the transformersThey are getting hot and the power cable was a little warm too after 3 minutes. Any ideas why?

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steveastrouk (author)taino12009-08-27

I have a feeling you may have damaged the primaries of one of them, or are you running 120V transformers on 240 V ? Post a little picture of the wiring setup. I wouldn't expect, with the secondary open circuited, that the CABLE would get warm. I'd expect maybe lukewarm after some time, but not hot. That said uwave transformers are made to a price, not a quality. The ones I've seen are welded to join the laminations, which is a Very Bad Thing for performance.

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taino1 (author)steveastrouk2009-08-27

Today I rewired the transformers with thinner wire from the cord . When I did the first test on each one of them they did not got hot ,just warmluke after a while but after hardwiring them with thicker wiring the problem began. So today I changed the wiring in one of them and only one started to get a little warm and the other one stayed cool. The volts reading were 124 for the primaries and 31.5 for the secondaries. Later tonight I 'll change the rest of the wiring and see what happens. I'm using 120 v. outlet.

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Re-design (author)2009-08-23

Give us a link to the instruction you are going by and a photo of your transformer would be good.

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taino1 (author)Re-design2009-08-23

thanks for the reply. I am going by the AAAWelder. Anyways, I'll look for larger trnasformers and hopefully this will solve the space problem to get the 20 turns. I the meantime I will finis the first transformer and will take a look to see how many volts it produces. I'll post any good news.

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