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Freeite-transformer core material help

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dark

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I have a ferrite transformer small surface mount which is driven by 200Khz nominal frequency . I need to know its core AL value is it ok to check this by winding turns on any side of E core , I can see space and fine insulated wire could creep through . Is this the way or it has to be disassembled ?


-d

PS:: : sorry there is a typo in the title of post it is "Ferrite"
 
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why do you need to know? the only things of interest in a premade transformer are the primary inductance, turns ratio, and saturation current. of course the nitty gritty would get into core losses and how hard you can push it, but Al wont tell you that anyway.
 
why do you need to know? the only things of interest in a premade transformer are the primary inductance, turns ratio, and saturation current. of course the nitty gritty would get into core losses and how hard you can push it, but Al wont tell you that anyway.

Actually my spec is saying worst case driver oscillator frequency could be around 550KHz . I was in the impression that Al value could give me some idea about the type of material anyways I could be wrong . What I am doing is trying to find a core material suitable for this ( E R 9.5 ) current output is only 200mA .

I am in a fix to do this as my application is requiring very odd voltage level and that too with ATEX other approvals , I attach schematic of what I am trying to do .

**broken link removed**
Rgds
Adi
 
Ungapped ferrites have a very wide tolerance, so it’s true that AL won’t tell you much in terms of which material it is. Is the converter using current mode or voltage mode control? If you’re running voltage mode the core material could be important in that there is a phenomena called “flux walking/ flux doubling” associated with push-pull converters. Typically power ferrites flux densities are kept below .3 Tesla, but your push-pull is running in both directions, so voltage mode control total flux swing should probably be kept to around, or just below, that level.
 
Ungapped ferrites have a very wide tolerance, so it’s true that AL won’t tell you much in terms of which material it is. Is the converter using current mode or voltage mode control? If you’re running voltage mode the core material could be important in that there is a phenomena called “flux walking/ flux doubling” associated with push-pull converters. Typically power ferrites flux densities are kept below .3 Tesla, but your push-pull is running in both directions, so voltage mode control total flux swing should probably be kept to around, or just below, that level.

Most likely it should be Voltage mode control , I am using this https://www.electro-tech-online.com/custompdfs/2010/02/MAX253.pdf as driver , I am unsure regarding the transformer as nothing much is said and the one I got as free samples are highly priced . Which ferrite material and gapped or ungapped looks some what critical selection to me here .
 
The driver just gives you a free running converter and you need to regulate the secondary in some fashon (maybe an LDO regulator). You don't need a gapped core here and for the frequency and power levels your looking for 3F3, 3C85, N87, or PC44 materials should be fine. Table 2 on page 14 tells you the number of turns to use (ratio) to use given your input voltage and what output you would like to have.
 
Thanks a lot for the material suggestion . I just calculated power it is Pt=2.48W and for core 3F3 (E R 9.5 ) I am getting 1.3W at ue=1130 . Could you help me if something is wrong here.

Edit: for 500Khz
 
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