SMPS transformers

Discussion in 'The Projects Forum' started by Disaster plus, Feb 3, 2013.

  1. Disaster plus

    Thread Starter New Member

    Jan 29, 2013
    3
    0
    Hi,

    I'm trying to design a half-bridge switched mode power supply running off 230VDC and providing 5A at 100VDC, but I am struggling to find a suitable transformer. All the transformers I can find either seem to have a power rating that is too low, or are far too bulky (size is an issue).
    Unfortunately I can't wind my own: I have to use off-the-shelf components so my design can easily be replicated by someone else.
    Does anyone have any ideas about a suitable transformer/store/alternative?
    Many thanks,

    DP
     
  2. takao21203

    Distinguished Member

    Apr 28, 2012
    3,577
    463
    Get them from China.

    Normally MOQ is 1000pcs.
    It is also possible in some cases only to order 100pcs.

    I know one vendor. 100pcs. means a higher price for each unit.

    + shipping DHL.
    + import tax.
    + locat VAT (21% here).

    This can nearly double the price for small orders. DHL shipping is added to the bill + taxed as well.

    I can help you if you have exact specifications for your transformer.

    Otherwise, you will have not much luck with SMPS transformers. They are uncommon except some smaller standard types. Even cores are hard to get, only some large distributors have a selection of suitable cores.
     
  3. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    Go to the TI/national semiconductor web site and look up their simple switcher prodducts like the LM2577 and others. They list transformer makers on the data sheet that supply theirs. You can call them and pretend to be some fake company that is designing a new server or whatever and they will probably sample you out a freebie that will work.

    Guess how I learned that..... I always claimed to be the senior designer at PowerCon Systems when I begged for free samples.
     
  4. takao21203

    Distinguished Member

    Apr 28, 2012
    3,577
    463
    I am not responsible for other people but I never claimed samples. Not legally and not illegally.

    Giving murky information is not likely to yield a professional result.

    Also posts like that make a forum look like run and and frequented by hobbyists, amateurs, pirates, and cobblers.

    I have some day simply requested information about a topic on a PI forum, and was offered a free SMPS PCB voluntarily. Without having to proclaim anything.

    If you don't have $50 now and then maybe do some different business.

    I have many 1000s of Inductors here- all kinds of. But only a few transformer cores.

    As I wrote the only way to source a transformer like that is to request at least 100pcs. + pay all the charges. No free samples here. It is not silicon.
     
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