Putting an Unknown Transformer to good use

Discussion in 'General Electronics Chat' started by DonWU, May 31, 2015.

  1. DonWU

    Thread Starter New Member

    Mar 13, 2011
    3
    0
    <Moderator's note: Your question is important enough to have its own thread so it gets more attention. Now you have your own thread.>

    I came across this thread when looking to find the VA rating on a transformer I have (it may have come out of an old model railway controller). There is single primary input and dual secondary outputs. At 230VAC input, the secondaries give 12.5VAC under no load The only marks visible are...1192-0087 NTC 9637...it weighs 960g and the windings measure 50 x 50 x 40 mm excluding the 'plates'. I thought it would be easy to search for and find the VA rating for this transformer, I assumed that NTC was the manufactures name or logo but I can up with nothing. Can someone come up with any info on this or point me in the right direction.

    Many thanks
    Don
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,498
    2,364
    What is the OA dimensions of the metal core itself ?
    Max.
     
  3. DonWU

    Thread Starter New Member

    Mar 13, 2011
    3
    0
    Hi Max
    Thanks for your interest

    The over-all core dimensions are 25 x 60 x 75 mm

    Regards
    Don
     
  4. Lestraveled

    Well-Known Member

    May 19, 2014
    1,957
    1,215
    My guess is 75 to 100 VA. What do you think, Max?
     
    Last edited: May 31, 2015
  5. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,498
    2,364
    I have one on the shelf practically identical dims, and it is stamped 50va.
    Max.
     
  6. DonWU

    Thread Starter New Member

    Mar 13, 2011
    3
    0
    Many thanks for replies, it's much appreciated,

    I'll consider this transformer 4 Amps max.

    Regards
    Don
     
  7. Lestraveled

    Well-Known Member

    May 19, 2014
    1,957
    1,215
    Don, you already have your answer and it is a good one. I would like to share some additional information that surprised me.

    I, like Max, looked at some transformers I have in hand. Here is some data.

    Core volume verses VA (outside dimensions)
    LP-30-1600 48VA 65,000 cubic mm
    F28-700 20VA 50,000 cubic mm
    The LP has 30% more core volume but is VA rated 240% higher than the F28.


    Dons Transformer has a core volume of about 112,000 cubic mm.
     
Loading...