AC-DC converter

Discussion in 'General Electronics Chat' started by praondevou, Jul 30, 2011.

  1. praondevou

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    I'm looking for a tiny AC-DC converter 120VAC to 5VDC. It doesn't have to have more than 50mA output current.

    I found this http://www.recom-international.com/pdf/Powerline-AC-DC/RAC01_02-SC.pdf on Digikey, but $14 is too expensive. There are some which are not isolated for $6, but I wanted them to be isolated.

    main thing here is they have to be CHEAP.
    Has anyone had this problem and found something? I don't want to build one by myself because it's going to be more expensive (component count).

    Thanks
     
  2. KJ6EAD

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  3. praondevou

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  4. iONic

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    They don't leave much room for spare change in there so the case dimensions are pretty much what you have inside.
     
    Last edited: Jul 30, 2011
  5. praondevou

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    Well, then it's too big... should a quarter of this at most.
     
  6. iONic

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    I think in this situation, money talks! 120VAC to 5VDC is not easy.
    It can be done without isolation, but I am not going to venture here.
     
  7. praondevou

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    Yes, for sure, and for a few mA it's not difficult. But I need them to be isolated.
    Thanks
     
  8. iONic

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  9. praondevou

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    I've seen it before and it made me smile. :D
    Too big with a 60Hz transformer and I guess more expensive than the off-the shelf encapsulated devices.

    EDIT: I found one , it's the BP5710 from ROHM, but 12V and $12, still too expensive
     
    Last edited: Jul 31, 2011
  10. blueroomelectronics

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    Buy thousands, they'll be much cheaper.
     
  11. Kermit2

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    How are you going to satisfy your polar opposite requirement?

    If one with a transformer is to big, you need a switching supply, if they are too expensive, then you need a non isolated supply, if you must have isolated then you are back to the transformer type.

    ???
     
  12. ErnieM

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  13. praondevou

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    :D Would you mind giving me loan for that?

    Problem is the 60Hz transformer, they are too big. They sell 5V wall chargers for $2, new. That means they could produce such converters. It's all a question of quantity. What I'm looking for is simply not being mass produced, that seems to be the problem...:)

    It's non-isolated, there is also one for $6,60, the BP5034D5, also non-isolated.

    Thanks for the input , guys.
     
  14. praondevou

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    I think I finally found the transformer isolated solution. It has to be CHEAP so I opened one of these chinese USB chargers which you can get for $1.50 on ebay.

    It's some kind of a super-simple smps, I'm curious to find out how it works. The secondary part certainly can be made smaller. They also will need a voltage regulator, since the output voltage can vary quite a bit. (+-0.5V)

    [​IMG]
     
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