Transformer Core: Questions About Lamination & Soldering

[jorjijon]

hello
i have a question about the transformer core.when we make it's core,we usually make it laminated to reduce eddy currents.but i saw that there is a soldeing in the corner of the transformer core.why we do this ?

 

[I_am_learning]

I have never seen such solder in the corner of the transformer core. Do you have pictures?

 

[Antiphon]

hello
i have a question about the transformer core.when we make it's core,we usually make it laminated to reduce eddy currents.but i saw that there is a soldeing in the corner of the transformer core.why we do this ?

It's a weld, not soldering. It's there to keep the laminations from vibrating or otherwise working loose.

 

[jorjijon]

It's a weld, not soldering. It's there to keep the laminations from vibrating or otherwise working loose.

Thank you very much.but still i have a question.by doing this way,don't we ruin our works to decrease eddy currents in the core??

 

[NascentOxygen]

All 4 corner edges are welded?

 

[jorjijon]

All 4 corner edges are welded?

yes.but doesn't it increase eddy currents(core losses) in the transformer?

 

[uart]

Would it surprise you if I said that you can electrically connect all of the laminations together and it won't (necessarily) increase eddy current loss?

The key feature of the laminations is that hey should allow no transverse conductive loop to encloses a significant amount of the flux. It is possible to apply a shallow weld in the corners without violating this feature.

 

[Carl Pugh]

Assuming that the core is E & I laminations and the weld is only on the outside.
The weld acts like a half turn of a conductor. The half turn puts a voltage across the inside of the laminations. If the volltage is low (60 hertz and a small transformer) then the current through the inside laminations is low and the loss is low.