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Help finding a high power source

  1. Feb 23, 2010 #1
    Hey guys, I'm working on a project and need to try and find a suitable power source to power it. I require a source capable of driving at least a 2.5 A DC through some magnet wire(about 250 ohm) so it needs to be 600 V and up. Problem is, outside of some very expensive power supplies i see online($1500 up), i can't seem to get this type of supply. My other alternative is to use a transformer and bridge it, question is, where can i find a transformer that would meet my requirements? Also, does anyone know if these transformers may be found in something i could perhaps find in a junkyard? any help would be appreciated.

    ps, it doesn't have to be a transformer, i should just be able to use it to get 600 V and 2 A DC.

    pps, i was thinking of using some NIB magnets and attaching them to my car axle and trying to make a generator out of that, but i dont know how feasable that would be, thoughts?
  2. jcsd
  3. Feb 23, 2010 #2


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    I know this is not what you asked, but...
    How are you planning to cool the magnet? 2.5A in 250 Ohm is 1.5kW= a lot of heat.

    One reason why you are finding it difficult to find such a supply (atlthough they do exist) is simply that it is not a good way to do things...

    Also, you do realize that you are talking about equipment that could easily kill you or someone else if something goes wrong?
  4. Feb 23, 2010 #3
    the coil will be wrapped around a hollow steel pipe which will have cold water flowing through it, the pipe is 8 cm wide so its a more than adequate heat sink. and yes i know this is uber dangerous, so i've designed everything in a way where i can just run the experiment from a distance.

    also you said its not a good way to do things, so then waht may i ask is?
  5. Feb 24, 2010 #4


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    Use fewer turns (=lower resistance) and a higher current. I just had a look at the small power supply we use for our small lab magnets (which are water-cooled, and still much stronger than anything you can DIY) and it is rated at 50A 60V. The supplies we use for superconducting magnets can deliver much higher currents than that, but can only source a few volts.
    Using a higher current will obviously not solve the cooling problem but at least you don't need hundreds of volts across a gadget made from wire where the only insulation is a thin layer of lacquer. I've never even heard of anyone using a high voltage supply with a magnet.

    Also, designing the "magnet" part of a big magnet is relatively easy, it is the cooling that is tricky; just wrapping the wire around a pipe is not likely to be enough if you have many layers of wire.

    Btw, how strong a magnet are you trying to build? 250 Ohms sounds like a lot of wire.
    Last edited: Feb 24, 2010
  6. Feb 24, 2010 #5
    unfortunately I'm trying to magnetize a rather large NIB magnet and require about 15000 Am to do so, as such my restrictions have been placed by the shape of the magnet as well as the required magnetizing strength, this is why i am using 32G wire, such that i only need one wrap to get my field. Since i am saturating a permanent magnet( which i did not mention sry), a higher than required B field would only be beneficiary as i will just max out on my hysteresis curve. So i am using 2 windings, this will actually take the resistance to 500 ohm thus making my generated required voltage right around 900V (current 1.8A) but still making my B field requirements.

    heres my thoughts on the generator idea:

    use a 3 cm circular iron block to house a series of small cylindrical NIB magnets(each rated at about 0.2 tesla at the distance i will place them away from the induction coils) so that they form a sort of daisy shaped object. I will then attach the block to a diesel powered motor(rated at about 4000 rpm) and use a resistive network to control the incoming potential, and then rectify the filtered wave to DC.
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