I’m trying to buy replacement bulbs for my halogen lamps. The lamps say “Maximum Wattage 100W”, but they say nothing of voltage. The bulbs that came with my lamps say “120V 100W”. I’m in the United States. The only bulbs that match this shape that I find for sale are in Europe and are printed “240V 100W”.

I understand I can buy bulbs with fewer watts but not more watts. What about volts?

Upon request in the comments, I am adding photos below.

If anyone can find a place to buy these bulbs, please share, I want to buy a lifetime supply since I recently heard halogen sales would be banned soon, thanks!

For those suggesting I buy LED, no thanks! Even the most expensive LEDs produce light that looks cold and feels sharp to my eyes, and that flickers in my peripheral vision.

The bulb I wish to replace: enter image description here

The stickers on the bottom of the lamp: enter image description here

The sticker on the socket of the lamp (lamp shade is unscrewed and removed): enter image description here

  • Can you post a picture of the bulb and the base, so others can see?
    – crip659
    Commented Jul 13, 2023 at 20:39
  • A 240V rated bulb plugged into a 120V supply will produce (theoretically) 1/4 of its rated wattage. I say theoretically because at half supply voltage it may never reach its designed operating temperature and resistance. But whatever the exact result it'll still be far less light output than expected.
    – brhans
    Commented Jul 13, 2023 at 20:43
  • Seconded on the picture of the bulb, add one of the sticker in the fixture as well. It seems quite likely that there's a correct sized halogen available domestically, and maybe even a quality LED replacement nowadays as well.
    – KMJ
    Commented Jul 13, 2023 at 20:53
  • @brhans I would like a expert to chime in. Not sure if the light bulb will not use double the amps to get 100w or just be dimmer as you say.
    – crip659
    Commented Jul 13, 2023 at 20:55
  • 2
    @crip659 is my Bachelors degree in EE expert enough? A resistive load like an incandescent light bulb is not a constant-power load like a switch-mode power supply is (like your typical phone charger wall-wart). It won't draw more current to compensate for the reduced voltage in an effort to produce the same output power.
    – brhans
    Commented Jul 13, 2023 at 21:10

2 Answers 2


The 220 lamp will light on 110 but it will not last very long. The filament needs to get hot enough for the halogen cycle to function, the low voltage does not allow that hence the filament does not get tungsten re-deposited on it and will fail much sooner. You will see the inside of the bulb blacken over time as it is operated.

The halogen cycle in a tungsten-halogen light bulb balances itself with cyclical reaction in which the tungsten that evaporates filament when illuminated is absorbed by the halogen gas and preferentially re-deposited at the hot-spots on the filament this prevents the early failure of the light bulb.


Those bulbs are obsolete and it's time to retire the fixture. Unfortunately there isn't a way to get quality LEDs that'll plug in to a halogen socket, since halogen lights are extremely compact for their light output, and worse, the fixtures are designed to keep the bulb hot*, and LEDs need to be cool.

  • and keep the bulb's heat from setting other things on fire...

If you run a European 240V bulb on 120V, you'll get somewhat less than 1/4 the light and a less blue color.

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