Hi. I am having trouble referring the equivalent circuit of a transformer. Can anyone give me some explanation? Thank you.

 

How complicated a model do you need?

 

Hi .
Here's an article about transformers in wikipedia .
for more explanation , you can refer to "Electric machinery fundamentals"/chapter 2 (transformer) .

 

How complicated a model do you need?

The question is that i get confused by the combinations:
how many cases will I face for finding the equivalent circuit of a transformer? 4?

-Step down referring to the primary
-Step down referring to the secondary
-Step up referring to the primary
-Step up referring to the secondary

Or 2 combinations of the above are the same?

 

I have always thought about a transformer being either isolation (1:1) , step-up, step-down, or both at the same time, with respect to the primary. For example, an audio output transformer is likely a step down, a tube power-supply plate transformer is a step up or could be both if it also has a filament winding, etc.