Need help with transformer wiring

Discussion in 'Archived Threads 2001-2004' started by TimForman, Jan 26, 2003.

  1. TimForman

    TimForman Supporting Actor

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    I'm trying my first amp build. It's just a mono 25W solid state. Nothing serious. I'm using a transformer I scrounged out of an old Onkyo receiver and don't know what all the wires are for. One side has 2 red, 1 black, 1 white and 1 yellow. The other side has 2 brown, 2 orange, 1 green and 1 blue wire. I think I only need to use half of the wires but I don't know which ones. Any suggestions?
     
  2. Jonathan M

    Jonathan M Second Unit

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    Hi there Tim,

    Firstly, which wires were hooked up where in the old amp??

    Secondly, you need to work out the relative resistances between each of the wires on each of the sides to divide the possibilities of dual secondaries and dual primaries.
    Do this by measuring the resistance between pair-wise cables. This is likely very small, so an accurate meter may be necessary to determine approximate voltages etc.

    Once you know how the various coils are arranged, you should at least be able to work out which ones are likely to be the main primaries. Then we can work on the rest.

    Once you've figured out this, post back, and we'll see if we can sort out the rest.
     
  3. Ted_Polzin

    Ted_Polzin Stunt Coordinator

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    You should also check what the secondaries are to make sure it will power your amp. If they are too high you could blow it up, to low and you won't get enough power. For 25 watts you need around 23volts Center tap. Also since it came from a commercial amp I would bet you have several secondaries in it. Your best bet is to figure out which wires are to the main power, Simply follow the mains configuration from the amp you took it from and read the power output, please be careful [​IMG], and then you can see what each secondary will be capable of.

    Ted
     

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