Reducing Inductance

Discussion in 'General Electronics Chat' started by magnet18, Jun 9, 2011.

  1. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Hey, I want to build the circuit in this page-http://www.ledsales.com.au/kits/nixie_supply.pdf
    But all I have is a 180 uH inductor, is there any way to reduce the inductance?
    A large resistor across the terminals perhaps?
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    A resistor across an inductor will just introduce loss, and dissipate power as heat.

    That circuit is basically the same as what Ronald Dekker posted on his site years ago:
    http://www.dos4ever.com/flyback/flyback.html

    You really should read through that page several times; it's an excellent resource for people wanting to learn about such things as boost converters, flyback converters, and how to make your own inductors for hobby projects.

    In the meantime, don't worry that the inductance is a bit high. You could slow down the 555's speed a bit to compensate by increasing C4 or R1 (Dekker's schematic) - or even try leaving it as it is for now.
     
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  3. Jaguarjoe

    Active Member

    Apr 7, 2010
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    90
    There is no correlation between resistance and inductance. Like apples and oranges.
    You can buy the correct inductor for a few pennies.
    You can wind your own inductor.
    You can place another inductor in parallel with yours.
    You can unravel some of the wire in your inductor.
    You can build another switcher designed around your inductor.
    You can skip Nixie tubes, join the 20th century and use LED's.

    How did your $2 meter quest turn out?
     
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  4. tom66

    Senior Member

    May 9, 2009
    2,613
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    If you have another inductor, paralled inductors follow the same property as resistors; decreasing inductance.

    Or you could push 10A through it, then you would have an inductor with 0 henries of inductance, although it may melt a bit and ESR may increase to a few hundred million billion ohms, and it might make a mess on your workbench. [Don't try it!]
     
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  5. SgtWookie

    Expert

    Jul 17, 2007
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    Radio Shack sells a 100uH inductor that's rated for 2A; it's wound on a ferrite rod. If you're worried about the exact inductance, you could use one of those; I've measured a couple of them and they were within a few percent.
     
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  6. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Okey dokey, thanks!

    Awesome, I'll keep that in mind

    never

    I managed to find 15 millammeters for $20 from lithuania, now I just need to test them and figure out what the new resistances I need are, and make a few diode bridges.

    Again Awesome, thanks
     
  7. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    124
    OH YEA, I just remembered I took notes over that page with all the math needed to test an inductor value with a scope, awesome :D
     
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