Transformer with parallel windings on one side - Cram for Exam Vol 2 Q 74

[akyip]

Hi guys,

Quick question about transformers with a parallel set of windings on one side.

For example, I'm working on Cram for Exam Volume 2. Question 74 shows a transformer with 2 primary windings, each of these windings has 100 turns. The equivalent turns for these 2 windings is just 100 turns, since they are connected in parallel. That is according to the solution.

From what I understand, parallel windings should have the same number of turns to prevent circulating current inside the transformer. So will the equivalent always be (Np1 + Np2)/2? Will this apply even if for example there are 2 parallel windings on just one side of the transformer, but with different number of turns from each other?

 

[Orchid PE]

If you come across a standard transformer with a different number of turns on the parallel windings, I think calculating the equivalent turns is the least of your concerns.

 

[akyip]

If you come across a standard transformer with a different number of turns on the parallel windings, I think calculating the equivalent turns is the least of your concerns.

I guess that's because of the circulating currents, correct?

And I think I just figured out the answer to my own question. If the parallel windings have an equal number of turns, then the current on that side will be evenly split among each parallel winding. And when you add the evenly split currents all up, the equivalent turns on that side will be the same as if the total current all flowed in the on equivalent winding. Does that sound right?

 

[Orchid PE]

I guess that's because of the circulating currents, correct?

And I think I just figured out the answer to my own question. If the parallel windings have an equal number of turns, then the current on that side will be evenly split among each parallel winding. And when you add the evenly split currents all up, the equivalent turns on that side will be the same as if the total current all flowed in the on equivalent winding. Does that sound right?

Correct.

 

[akyip]

Chattaneer, you are one of the best responders I've seen here since I recently joined this board to prep up for this April exam. Thank you very much!

 

[Cram For The PE]

I guess that's because of the circulating currents, correct?

And I think I just figured out the answer to my own question. If the parallel windings have an equal number of turns, then the current on that side will be evenly split among each parallel winding. And when you add the evenly split currents all up, the equivalent turns on that side will be the same as if the total current all flowed in the on equivalent winding. Does that sound right?

you got it.

 

[Dude99]

 I think it works like this