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Electronics building an ad-hoc flyback supply.

Discussion in 'Modding' started by OtakuHawk, 11 Feb 2007.

  1. OtakuHawk

    OtakuHawk What's a Dremel?

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    hey folks. i'm trying to cobble together an HV power supply from a bunch of things. and i'm not sure if it'll work. I really don't have a full lab setup to test things out with.

    [​IMG]

    the inside of the dimmer looks kinda like this

    am I missing anything big here? or will I be able to draw a decent arc from this? (assuming I don't smoke the flyback xfrmr secondary) the first transformer is current-limited to 2.5 A on the 2ndary, so I'm not too worried about it.
     
  2. ConKbot of Doom

    ConKbot of Doom Minimodder

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    it'll make something, but the dimmer isnt really meant for inductive loads, so the componets inside of it, may start to avalance and not allow your inductive spike to grow very large.
     
  3. OtakuHawk

    OtakuHawk What's a Dremel?

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    so put a few HV diodes between the dimmer and flyback primary?
     
  4. Moriquendi

    Moriquendi Bit Tech Biker

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    You might have better luck with a variac (variable ratio autotransformer) but be aware that it will not provide any isolation from the mains.

    Moriquendi
     
  5. ConKbot of Doom

    ConKbot of Doom Minimodder

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  6. xen0morph

    xen0morph Bargain wine connoisseur

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    I might be wrong, but I think flybacks are meant to be driven at very high frequency in order to generate their rated output voltage. If you try and run them from 50 or 60hz mains power you might burn out the flyback.
     
  7. OtakuHawk

    OtakuHawk What's a Dremel?

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    that's what the dimmer is for. it's an SCR that turns the circuit off halfway through the waveform, giving me a nice HF falling edge.
     
  8. ConKbot of Doom

    ConKbot of Doom Minimodder

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    Dimmers turn off at the zero crossing, and turn on partially though the cycle, but the 4hv wiki entry says you can use a dimmer an a series cap to limit current so, do a little searching on cap value to use, and give it a shot.
     
  9. JazX101

    JazX101 What's a Dremel?

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    Lo!
    Why not take a lil walk down to you're local TV repair shop, or a car park where ppl dump stuff, and see if you can find/ borrow/ steal etc a flyback transformer from a nice big old wide screen TV. Should give you a lot better performance, and probably a lot more control of how much voltage you're playin with. Only down side is that you might be able to get into the really really lethal voltages, and give you're self one final zap before snuffing it. I would suggest avoiding that, as it severly curtails you're enjoyment of your nice new HV supply.
    Jaz_knos
     
  10. Moriquendi

    Moriquendi Bit Tech Biker

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    He already has a flyback, we're discussing how to drive it to get a variable output voltage.

    Moriquendi
     
  11. JazX101

    JazX101 What's a Dremel?

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    Ah, reet, probably a bit more reading of the other stuff in the thread would have been helpfull here!
    Would it not be possible to alter the flyback voltage by varying the couplance between the flyback and the main coil? would mean you could have a nice simple stable power-supply and just adjust the one thing??
    If you're puzzling about the light switch dimmer thingie, why not try it at a low voltage, just too test. Worst that happens is you dont get it to do anything, which means it either doent work or you have a dud coil.
    Jaz_knos
     

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