Author Options:

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.




Best Answer 8 years ago

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

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

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

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?

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.

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.

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 ?

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.

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

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?

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.

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.

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

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.