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Making a hot wire

  1. Feb 12, 2015 #1
    I am planning in making a boiling tube that heats up to about 200c without a flame. I was thinking a coil of wire and a 9v battery (portable is always better). How would I make the wire hot - 200c/300c with only a 9v battery.
     
  2. jcsd
  3. Feb 12, 2015 #2

    mfb

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    Staff: Mentor

    If you insulate your system well enough (that is not trivial), reaching that temperature is easy.
    Controlling the temperature can be interesting.
     
  4. Feb 12, 2015 #3

    davenn

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    Yup, but it isn't going to be done with one of those small PP3 9V batteries, they just don't have the umph,
    they can only supply around 300-400 mA and for a relatively short time
    You would need a battery that can supply significant current, say a 12V 7.2 AH Gel or sealed Lead-Acid

    Dave
     
  5. Feb 12, 2015 #4

    mfb

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    I don't know how large the volume we want to heat is.
    You can make a thin wire visibly glow red with ~2A, using a thinner wire should easily give 200°C with 200mA.
    9 V at 200 mA means 40 Ohm, so we can use a long thin wire (or probably a small resistor).
     
  6. Feb 12, 2015 #5
    I think wolfram based wires are very suitable for this.
     
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