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
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