Help Identifying transformers?

Discussion in 'General Electronics Chat' started by santonel, Feb 28, 2010.

  1. santonel

    Thread Starter New Member

    Feb 28, 2010
    I had a couple dead ATX computer power supplies that I scrapped for parts. I pulled a few transformers out of it. Two are (comparatively) large and there's about 6 smaller ones too. The larger ones have a large bundle of thick wires sticking out of it that is wound together and insulated. Anybody know what these are for? I've tried to google for them but I can't find any data on them. Anybody know anything about them? Are they useful or are they only good for that one application?

    Any help is appreciated!
  2. BillB3857

    Senior Member

    Feb 28, 2009
    ATX power supplies are, for the most part, switching supplies that rely on Pulse Width Modulated (PWM)relatively high voltage power going to the primary and the high current low voltage comes off the secondary feeding the rectifiers and filters. The large, twisted, wires are in all likelihood, the secondaries. This type transformer needs to be used in high frequency PWM applications.
  3. JDT

    Well-Known Member

    Feb 12, 2009
    I have attached a couple of circuit diagrams of typical ATX power supplies for your interest. As BillB3857 says the transformers are high frequency types and not very useful as parts. Worth saving the power semiconductors and the heatsinks for home projects.
    santonel likes this.
  4. santonel

    Thread Starter New Member

    Feb 28, 2010
    Thanks for the schematics! Unless I'm reading them wrong the big twisted wire seems to be the secondary ground right?

    Also when you say high frequency what kind of frequencies are we talking here? Will it just not work at low frequencies or will it just be really inefficient? I kept them thinking they may be useful as an inter-stage audio transformer or for some high voltage application. Either way I think Ill hang onto them. Who knows, maybe one day Ill want to build an SMPS?