^ Correct. I would drop almost. If you double the voltage, power is quadrupled for the same bulb.

Correct; the above posts do the math. However, if you put a 120v bulb on a 240v line, it will burn out in less time than it takes to read this sentence. You'll get a lot of light out of it while it lasts, though.

That said, the original question postulated European (hence 230v) bulbs. That raises other issues, but not this one.

Yes, a proper bulb changes the entire equation. I assume the switch could handle the extra voltage, but I would check that. Of course, a local hardware store could easily answer all the questions, but that would be too easy and deprive us of an interesting exercise.

I wonder if the lamp would be CE approved?

the real question is............how many FTers does it take to change a lightbulb?

Most electrical lamp stuff for usa market is built 110-220 ac/dc, with the 110 not being exactaly 110, and the 220 not being exactally 220. if it indicates it is 220, it will run on 220 or 240v ac with no problem. the only components in most lamps are a switch, a socket, a plug, and a few pieces of wire. you should be able to find the voltage limit on the socket, switch and plug.

the biggest problem that one would encounter with wire is exceeding the current (amperage) limitation. that occurs when going to lower voltage, and increasing the amperage.as in taking a 100 watt 240 volt lamp and running it at 12 volts 100 watts.

in the usa, there are other completely ....... voltages between 250 and 440. they are usually only in commercial buildings, that combine various forms of 3 phase.

i do not know about socket/bulb compatibilities.

I somehow missed the part about using 220V bulb. Higher voltage is of no consequence. It's the current that matters. Since 110V bulbs have lower resistance and hence carry higher current than 220V bulbs, the wiring in the U.S. appliances is designed for higher current. Using a US made lamp in Europe wouldn't have any overloading issues if a local bulb is used. The only issues the OP would have is making a local bulb fit in the bulb receptacle and the plug fit in the wall socket.

Not if the higher voltage is enough to short the insulation inside the cord, which (if a U.S. cord) may not have been designed to handle it. At that point the current that the bulb would draw is irrelevant. You have a short circuit.

Rewiring a lamp is the simplest electrical job there is, with the possible exception of replacing the batteries in a TV remote. Do it.

Going from 110V to 220V or even 250V isn't going to cross the breakdown voltage. Bigger concern is whether the wire is able to handle higher current. But 220V bulb or any other appliance draws less current than 110V ones for the same power. Rewiring is not required at all. Whether the base of the bulb can fit in the socket, has one or two electrodes at the base of the bulb and a plug that fits into the socket are the two issues. I believe, in U.K the bulbs are bayonet mount with two electrodes, as opposed to screw mount with one electrode. Saying Europe isn't enough. You need to know the type of bulb and the type of socket as they vary from country to country even within Europe.

Birds hang from high tension wires, you could too, with bare hands, without being electrocuted, as long as you don't ground yourself. ;)

Since you are on FT, I am sure you travel around the world. Do you re-wire all your small appliances, such as dual voltage shavers, hair dryers, cell phone/pda charging units? Think about it. Unless you are talking about really high voltages approaching breakdown voltage of the insulation, higher voltage is of no consequence in these cases.

Totally irrelevant, to the point that it raises questions about how well the poster understands electricity. There is no potential difference between the two points where the bird's feet touch on the same wire.

Every one of those examples is intended to be used at 240v and is designed with that in mind. Lamps are not. Again, this raises questions about the extent to which the poster understand the issues.

We are talking about peak (not RMS) voltages that could exceed the breakdown voltage of the internal insulation of cords used in U.S. lamps. This is not something worth taking a risk on, given the trivial effort and/or cost involved in rewiring a lamp.

Now now. Have you looked into the mirror since you made the statement that I have taken the liberty to bold. ;)
Once again, it's the current and hence the thickness of the wires that are of concern between wiring for 220 and 100 V appliances. Voltage is minimal comapred to the breakdown potentials that are tens of thousands of volts per milimetre.

The voltage we are talking about, of the order of a 100 Volts, is as good as zero when compared to the break down potential. I am afraid, you are the one missing the point my friend. Moreover the difference between peak and RMS is factor of square root of 2, far far lower than the voltages involved in breakdown of insulation. It appears you are the one who needs to understand the terms you interject here. Even air has dielectric strength of 3MV/m or 3000 volts per mm. Any insulation will have a higher dielectric strength than that of air. Nylon's dielectric strength is 14000 volts per mm. So your argument is completely bogus.

The example of the bird is very relevant. If the difference between 100 and 200 volts were of concern to insulation, dielectric strength of air should be of concern to you when hanging from a bare high tension wire. Dielectric strength of damp air would be much less than the 3000 Volts/meter. It's not the potential difference between the bird's feet or your hands that's the issue here. The issue is the insulation of the air between the HT and LT wires.

On a dry day when you get a shock when touching a door knob, it's due to dielectric breakdown of air. The voltages involved are very high, much much higher than the 220V volts you are hung up on. The reason you don't die is that the current is very small.

The thickness of wires is, indeed, the main concern.

However, most wires used in North American appliances are rated at either 125V, 300V, or 600V. Virtually all consumer-grade switches are rated at ~125V. While, in practice, this is not very likely to cause a problem, the use of 125V-rated wires and/or switches would still, technically, be a safety violation.

This was around twenty years ago, but when my family moved to Germany, we took lamps with us. Using plug adapters and 220v bulbs with our existing lamp fixtures worked fine for us for the almost 3 year time we were there. I did inadvertently install a 110v bulb once, and it flashed briefly before burning out, similar to what often happens normally when a bulb burns out.

I love it!

The real answer is can anyone figure out how many bonus miles we can get from buying the parts online to rewire? If it's greater than 1 then you know the correct answer :-)

Most US off-the-shelf electrical wire, including the popular zip cord used in wiring lamps, is rated for both 110v and 220v. I think I mentioned that earlier in the thread, but maybe not.

Most modern UK bulbs are bayonet with two - but older UK bulbs are screw with one.

Although your average supermarket will only sell bayonet, you can get a screw in at larger stores for old lamps: when I bought an old house which was re-wired in the 60s I had to buy the screwins until I'd rewired the house (and I'd got rid of the small round pin bakalite sockets... oddly, wired into the lighting circuit :eek:).

Remember, even in the UK, there can be different standards...