Transformer design

Hello,

As far as I know, the lower voltage windings are mounted on the inside so that the insulation required is lesser than having the high voltage winding on the inside.. but the LV winding doesn't necessarily have to be the primary winding.. so I guess that does not really answer your question... Also the transformer you have considered seems to be a one-to-one transformer, which does not really help either..

Any electrical insulation paper is needed to place between each two layers of the windings?

Yes, insulation is needed in between the windings also..

Let me explain it to you in a bit more detail... but I must warn you that what I have is Textbook knowledge.. after all I'm only doing my final year in Electrical Engineering :

Actually, there are two types of transformer designs...core type and

shell type. (see image below
(a)).In core type, as you can see the windings surround the two limbs of the core. Here the LV winding is placed on the inside followed by an insulation and then HV winding placed over the insulation..

In shell type (image(b))on the other hand, the alternate layers of LV and HV separated by insulations surround the central limb..

The insulation used can be paper,mica, etc.

But in the core type, is there an advantage to put one or the other winding on the inside ?

Hello,

I believe the advantage of having HV winding on the outside in a core type transformer is that it is easier to have tappings on the outside, in order to get variable voltage..but I'm not quite sure....