Standard gap for ferrite for flyback converter

[nhatspkt]

The paragraph that i marked yellow color. The author mention about that:

From the calculate: lgap = 17 mils why the author select standard gap for this core 67mils with an AL of 100mH/1000T?
Reference : Power Supply Cookbook, Second Edition By Marty Brown

 

[Silvio]

The paragraph that i marked yellow color. The author mention about that:
View attachment 7157
From the calculate: lgap = 17 mils why the author select standard gap for this core 67mils with an AL of 100mH/1000T?
Reference : Power Supply Cookbook, Second Edition By Marty Brown

From what I am assuming is that not everybody has the means of making a gap in a standard non gap core. From what I am thinking is that he is preferring to use a standard gapped core with the minimum gap available at the time of writing the book.

However there is a means that one can put a spacer between the cores to create the gap. The gap will be on the three legs however the spacer thickness has to be half of the said dimension. This way there will be also some EMI generated from the ends of the core as the gap is present on the three legs instead of the middle leg only.

 

[nhatspkt]

Can you give me some advice how to calculate flyback tranformer and select Bmax, D ?

 

[Silvio]

Can you give me some advice how to calculate flyback tranformer and select Bmax, D ?[/LinQUOTE]

Here is some software that you can download and this will calculate everything for you, You have various software programs for flyback, half and full bridge etc. Select the one you need.

Link https://www.diysmps.com/forums/show...tors/page13&highlight=transformer+design+tool

Regards

Silvio

 

[nhatspkt]

Hi Silvio,
A few year ago, I have been used this tool for calculating. But I'm feeling that the result for calculate is not correct. Would you like to tell me some book that mention about calculating transformer for SMPS?

Best regards,
NHAT DAO

 

[res_smps]

please check AN-4137 fairchild