Help Identifying unknown Transformer

Discussion in 'General Electronics Chat' started by Clark44, Aug 13, 2014.

  1. Clark44

    Thread Starter New Member

    Aug 11, 2014
    15
    0
    Hello

    I got this transformer from an old ups, there are four wires on the primary side black, blue, green , yellow and two on the secondary red and blue. This transformer used to charge 12v 7.5ah battery also converts it back to 220V in backup mode.
    Tried testing its output and got this

    (Mains 220V)
    Black to ground
    Blue to mains-> 7.9v on secondary
    Green->5.5v
    Yellow->6.5v

    Connecting Blue and Green to mains and it was a shot circuit and blown my fuse. I want to use this for making a decent power supply 12v+ output, is this possible?

    I also saw this video https://www.youtube.com/watch?v=mc4GZM-kFUY&hd=1
    The guy is using his ups transformer for generating hv to power cfl using tip122, i am not sure how to do this using my transformer.

    I need to make use of this transformer somehow, otherwise its just eating dust at my home.
     
  2. bhvm

    Active Member

    Jul 16, 2009
    53
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    Last edited: Aug 13, 2014
  3. Electric Al

    Member

    Nov 6, 2013
    58
    8

    I see numbers on the transformer , and I would suggest googling those numbers , and see what comes up !
     
  4. Clark44

    Thread Starter New Member

    Aug 11, 2014
    15
    0
    Well, thanks for the info, but i don't think the windings are similar, what you have is multitap transformer and what i have seems to have only two windings for main primary and secondary and its output voltages are right above, and it can't be that this huge thing only giving about 7.9v max.
     
  5. Clark44

    Thread Starter New Member

    Aug 11, 2014
    15
    0
    I did before asking here, nothing important comes up.
     
  6. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    Find the winding with the most ohms. That will be the 220v winding.

    That should be safe to connect to the mains, but PLEASE connect it through a 2A fuse when you test it.
     
  7. atferrari

    AAC Fanatic!

    Jan 6, 2004
    2,645
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  8. b1u3sf4n09

    Member

    May 23, 2014
    115
    14
    I've attached a section from the ARRL handbook concerning the identification of unknown transformers. It offers some helpful suggestions.
     
  9. Clark44

    Thread Starter New Member

    Aug 11, 2014
    15
    0
    Well, i am not really sure what happened. I was wondering myself with the weird voltage outputs. I was testing voltages by using only bridge rectifier made of 1N4007, outputs were same as written above. Now i thought why not try filter the output using capacitor. And i putted 1000uf 25v in the output and here we go 12v output clean and stable output. Now green 8v, yellow 9v and blue 12v. Any comment on this?
     
  10. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    in the earlhy days of radio, transformer windings were color coded and the various manufacturers used the same color codes. I dont know when things changed, but it sould sure be nice if they standardized them again. such as black for primary and such.
     
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