Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Light bulb

  1. Aug 23, 2008 #1
    Hi everyone,
    In a light bulb, as we increase the temperature of the light bulb, the colour produced by the light bulb changes from red to blue ( intensity vs frequency curve shifts to the left).
    But if i want to have a red bulb with higher intensity ( i.e. brighter red) without the colour being changed what do i do?
  2. jcsd
  3. Aug 23, 2008 #2
    Run the filaments at lower current, but more of them.

    Dye the bulb red.

    Use a gas in the bulb that glows red (or do you want orange?) Have you seen those flickering candle bulbs? I don't know how it's done.

    Edit: In reconsidering, at a guess, you don't want to make or modify your own light bulb. Perhaps you could try to series two 120VAC bulbs and get a nice orange glow out of them.
  4. Aug 23, 2008 #3


    User Avatar
    Science Advisor

    Spend the extra money and buy the infrared bulb? They have a pretty high-intensity red, but this might be a little too far to the red for your liking (considering they're meant to be used to keep food hot), and they're really expensive.

    You could also go with non-blackbody gas-filled bulbs which radiate at a single (or a few) frequencies. Helium, maybe? Neon signs use phosphors to change the UV part of the emission to whatever the desired light is.

    I've also seen colored LED and fluorescent light bulbs in hardware stores around town, though I've never been able to justify purchasing any.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Light bulb