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I understand that the thing that allow a lightbulb to glow white high is the fast amount of resistance the electrons face with all the many spiral the filament has. But I need a thicker more resistant filament so is there another way to increase resistance?

Wesley Lee
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DeusIIXII
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    Make it longer. – Wesley Lee Feb 02 '17 at 21:43
  • That would work but it need to able to handle extreme pressure up to 300-1500 psi, mostly from expanding oxygen it will face. I will use aluminum for the oxidation FYI I heard it helps. – DeusIIXII Feb 02 '17 at 21:55
  • Refer to Ohm's Law: $ R = {\rho}{\ell} / A $ . –  Feb 02 '17 at 22:03
  • you only have 3 options:
    1. make it longer.
    2. make it thinner (smaller cross sectional area).
    3. use a different material with a higher resistivity.

    Nichrome is the material they use for most electric heating elements, which if you don't need the light works quite well. It's also relatively resilient to oxidation.

     – helloworld922 Feb 02 '17 at 22:03
  • use quartz and halogen gas (iodine ,bromide) to operate at higher temp. Tungsten has a fixed tempco and linear R with length and 1/Area. Shorter filaments are more robust, so cascading short terminated filaments may be the better choice but then heat is lost in conduction to terminator lowering R with T – Tony Stewart EE75 Feb 02 '17 at 22:04
  • Helloworld922, can nichrome heat up as fast as tungsten? It to heat up to around 1500-2500 °F very fast in millisecond. – DeusIIXII Feb 02 '17 at 22:07
  • Yes @DeusIIXII Try Nichrome embedded in glass poured inside TO-3 Can and pulse with 10A for 2 ms to get high IR emissivity – Tony Stewart EE75 Feb 02 '17 at 22:09
  • It might help us to help you if you tell us exactly what you are trying to do with this. – RoyC Feb 03 '17 at 00:06
  • As was commented on in your previous version of this question, there is no way to protect your filament. At incandescence, aluminum will burn very nicely, thank you very much. You must not allow oxygen to contact any material this hot, regardless of pressure. – WhatRoughBeast Feb 03 '17 at 00:56
  • There have been studies and even patent applications that say other wise.. As was also stated in my other comment. – DeusIIXII Feb 03 '17 at 00:56
  • Most metals burn well in high-oxygen environments (a thermal lance burn iron rods in a pure oxygen environment). Aluminium melts at only six hundred-something degrees C, you can forget about any candescence. There are ceramics which hold up quite well under oxygen (hardly surprising as many are oxides) but they aren't conductive. Tungsten burns quite well in air, if you don't believe me, smash a light bulb and turn it on, you'll see yellow tungsten trioxide (WO3) splattered everywhere. And for the record, resistance isn't "fast" or has anything to do with "spirals", electrons just bash atoms – Sam Feb 04 '17 at 00:29

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