Transformer Winding

[microsim444]

What is the best way to wind the SMPS transformers?

All primary - Secondary ?

Primary - All secondary - Primary ?

How to calculate the wire thickness needed. and number of turns for each side

Output voltage required is +/- 90VDC with 5Amp for each rail at 50 Khz

Cores available is ETD49, ETD 59

Thanks for the help

 

[paladinox]

Try:
http://sziget.mine.nu/~danko/letoltes/Magnetics_design_application_notes.pdf

and
Practical Switching Power Supply Design -MOTOROLA.pdf
at
http://www.4shared.com/file/6722272...tching_Power_Supply_Design_-MOTOROLA.html?s=1

 

[microsim444]

Hi

Many thanks for those links, they have very good informations.


What power do we expect from the ETD-59 at 125KHz

 

[paladinox]

Be careful with skin effect at this freq.

I think this core can handle more than 2kw at 125kHz.

 

[megajocke]

Even more than 2kW should be possible but proximity effect becomes a real problem at those frequencies and you need to be very careful. Litz wire or foil winding is probably the best solution. At lower frequency it should be possible to use standard wire and you can still get quite a lot of power through an ETD-59 even at 25kHz...