What makes the construction of power and pulse transformers different?

[smruti]

what is the difference between the construction of a power transformer and a pulse transformer used in high frequency application and what about their core and copper losses?

 

[Hesch]

what about their core and copper losses?

The core of power transformers is made of sheet iron added silicon to reduce iron losses.

In a high frequency transformer a ceramic core is used, having only electric conductivity located in small particles, thus the ironlosses are tiny. The windings can be litz wire to reduce copper losses.

 

[Baluncore]

The magnetic particle diameter or lamination thickness should not be more than twice the skin depth at the maximum frequency of operation.
http://en.wikipedia.org/wiki/Skin_effect
If the magnetic material is thicker than needed then the material in the centre of the lamination will not be accessible to the magnetic field. That will make a heavier and more bulky core, that will in turn need more winding wire.

A power transformer can use thick laminations because it operates at 50 or 60Hz.
A pulse transformer needs a very fine iron powder or ferrite core material.

At higher frequencies only the surface of conductors carries AC current. It is therefore necessary to use thicker wire or litz wire at higher frequencies.
http://en.wikipedia.org/wiki/Litz_wire

 

[Baluncore]

Here are some pdf files on the practice of transformer design.

slup124 Magnetic Core Characteristics. http://www.ti.com/lit/ml/slup124/slup124.pdf

slup126 Power Transformer Design. http://www.ti.com/lit/ml/slup126/slup126.pdf

Inverter Transformer Core Design and Material Selection. http://www.mag-inc.com.cn/File%20Library/Product%20Literature/Strip%20Wound%20Core%20Literature/Inverter-Transformer-Core-Design-and-Material-Seletion-EN.pdf

 

[nsaspook]

Cool video about the transformers we see every day.