My lamp exploded - can I re-wire it so that it will work with different voltages?

Questions on how we spend our money and our time - consumer goods and services, home and vehicle, leisure and recreational activities
Post Reply
Topic Author
Caduceus
Posts: 2133
Joined: Mon Sep 17, 2012 1:47 am

My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Caduceus » Sat Mar 09, 2019 4:42 am

I gave one of my relatives a vintage lamp that's been in our family for a while, but she lives in a country with a different voltage (220v) I think, and the bulb burnt really brightly for a while, and then kinda made an exploding sound.

In order for it to work safely, can we just use a bulb that's rated for 220v and plug it into the lamp, or do we have to re-wire the entire thing?

And if so, is there a way to re-wire the lamp so that it can handle BOTH US voltage and foreign voltage? (E.g. if we re-wire the lamp to 220v, will it still work in the U.S.?)

The Wizard
Posts: 13356
Joined: Tue Mar 23, 2010 1:45 pm
Location: Reading, MA

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by The Wizard » Sat Mar 09, 2019 4:52 am

Wiring itself doesn't much matter.
It's the BULB that matters, whether incandescent, CFL, or LED.
Plus you'll need a proper socket for the bulb; likely that 220 volt bulbs use different socket than US standard(s) for 120 volts.

Also need adapter for the plug, but that's easy, just use travel adapter...
Attempted new signature...

DiploInvestor
Posts: 85
Joined: Sat May 12, 2018 9:26 am

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by DiploInvestor » Sat Mar 09, 2019 4:56 am

Overseas is generally 50 Hz as well, which requires heavier duty wiring. Best to rewire for 50Hz, and change bulbs and plug adapters depending on where you are using the lamp.
"History doesn’t repeat itself, but it often rhymes." -- Mark Twain

The Wizard
Posts: 13356
Joined: Tue Mar 23, 2010 1:45 pm
Location: Reading, MA

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by The Wizard » Sat Mar 09, 2019 5:02 am

50 hz has nothing to do with wiring, only matters with a motor or a clock, not the OP's lamp. And there's no way to "rewire for 50 Hz".

And the lamp will be drawing 1/2 the current at double the voltage, so thinner wiring would actually be okay, but this is a LAMP, not a heavy duty power tool...
Attempted new signature...

Topic Author
Caduceus
Posts: 2133
Joined: Mon Sep 17, 2012 1:47 am

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Caduceus » Sat Mar 09, 2019 5:12 am

Yes, so this is exactly what I don't understand. Are all lamp wirings (this is a vintage lamp) capable of bearing different voltages? And so it's just the bulb I need to change?
The Wizard wrote:
Sat Mar 09, 2019 5:02 am
50 hz has nothing to do with wiring, only matters with a motor or a clock, not the OP's lamp. And there's no way to "rewire for 50 Hz".

And the lamp will be drawing 1/2 the current at double the voltage, so thinner wiring would actually be okay, but this is a LAMP, not a heavy duty power tool...
Why would it matter with a clock or a motor, but not with my lamp? I'm concerned about safety, mostly. My goal is to have a lamp that can work anywhere in the world. Is the best solution to replace the wire/socket for the highest possible voltage - would it then work in an area with a low voltage?

The Wizard
Posts: 13356
Joined: Tue Mar 23, 2010 1:45 pm
Location: Reading, MA

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by The Wizard » Sat Mar 09, 2019 5:21 am

Caduceus wrote:
Sat Mar 09, 2019 5:12 am
Yes, so this is exactly what I don't understand. Are all lamp wirings (this is a vintage lamp) capable of bearing different voltages? And so it's just the bulb I need to change?
That is basically correct, especially for an incandescent bulb which I assume you are using.

Technically you need heavier wiring when drawing higher current, but 240 volts draws 1/2 the current for the same watt bulb as 120 volts, so US wiring will be fine.

Also technically, higher voltages need better insulation to prevent arcing and shorts, but 240 volts isn't that high. Most consumer wiring insulation seems to be rated for up to 600 volts from what I've seen...
Attempted new signature...

mrc
Posts: 1399
Joined: Sun Jan 10, 2016 6:39 am

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by mrc » Sat Mar 09, 2019 5:58 am

Caduceus wrote:
Sat Mar 09, 2019 5:12 am
Why would it matter with a clock or a motor, but not with my lamp? I'm concerned about safety, mostly. My goal is to have a lamp that can work anywhere in the world. Is the best solution to replace the wire/socket for the highest possible voltage - would it then work in an area with a low voltage?
Because both clocks and (some) electric motors depend on the 60Hz frequency. Good overview on voltage & frequency on wiki.
Macs are for those who don’t want to know why their computer works | Linux is for those who do | DOS is for those who want to know why their computer doesn’t work | Windows is for those who don’t

Ping Pong
Posts: 512
Joined: Fri Feb 20, 2009 12:51 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Ping Pong » Sat Mar 09, 2019 6:33 am

We re-wired an antique lamp that was from a different voltage country. It’s like a 10 minute job. We got some antique style wire off the internet and put a new light socket on it. Ours hangs from the ceiling on the wire so the look of the wire mattered in our case.

New wire today will almost assuredly work with either voltage. Our old wiring was using a clothlike insulation, and we couldn’t be sure how good it still was so we replaced it.

The lamp socket is going to be specific to the voltage of your country, you’ll have to change it when you change countries. It’ll take less time than going through customs.

mggray17
Posts: 116
Joined: Thu Feb 11, 2010 8:09 am

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by mggray17 » Sat Mar 09, 2019 7:05 am

The wire size is based on the current, not the voltage. As someone pointed out using 220 volts with something that with a load (bulb) that was designed for 120 volts will draw half the current. The wire for this range of voltage is typically rated for 600 volts. So the wire is not the issue. The issue is the the plug and receptacle are designed for either 120v or they're designed for 220v. They would be different as far as the spacing and arrangement of blades and the bulb was not rated for 220v. The bulb socket may or may not be different.

wilked
Posts: 1662
Joined: Thu Mar 24, 2011 1:50 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by wilked » Sat Mar 09, 2019 7:17 am

Buy a used crappy 220V lamp, similar dimensions. Take the electronics out, replace them into your antique lamp. Done.

User avatar
oldcomputerguy
Moderator
Posts: 6811
Joined: Sun Nov 22, 2015 6:50 am
Location: In the middle of five acres of woods in East Tennessee

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by oldcomputerguy » Sat Mar 09, 2019 7:45 am

The Wizard wrote:
Sat Mar 09, 2019 5:02 am
50 hz has nothing to do with wiring, only matters with a motor or a clock, not the OP's lamp. And there's no way to "rewire for 50 Hz".

And the lamp will be drawing 1/2 the current at double the voltage, so thinner wiring would actually be okay, but this is a LAMP, not a heavy duty power tool...
If the bulb is rated for 220v, then yes, that's true. For a given power dissipation, if the voltage is double, the current draw will be half. This also contributed to why the original bulb failed so spectacularly; per Ohm's Law, if the voltage fed to the lamp goes from 110v to 220v, the current doubles (and the power dissipated in the bulb, equalling voltage times current, quadrupled).

Boom!
"I’ve come around to this: If you’re dumb, surround yourself with smart people; and if you’re smart, surround yourself with smart people who disagree with you." (Aaron Sorkin)

User avatar
SlowMovingInvestor
Posts: 1606
Joined: Sun Sep 11, 2016 11:27 am

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by SlowMovingInvestor » Sat Mar 09, 2019 8:11 am

Why not get a transformer ? I know there are portable transformers that are inexpensive.

ADDED: The non technical term would be converter :)
Last edited by SlowMovingInvestor on Sat Mar 09, 2019 9:35 am, edited 1 time in total.

Jack FFR1846
Posts: 10800
Joined: Tue Dec 31, 2013 7:05 am
Location: 26 miles, 385 yards west of Copley Square

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Jack FFR1846 » Sat Mar 09, 2019 8:22 am

The wiring is very likely rated for 240Vac already. Look at it. Lots of times, you'll see markings right on the wiring. As mentioned, the plug is different. The receptical for the light may or may not be rated for 220Vac. If you look at it, there will definitely be markings. Incandescent light bulbs act as resistors. The Watt ratings are only approximate and only at the specified voltage. At double the voltage, you'll see double the current. Devices with switch mode power supplies will act as constant power devices, so they will indeed input about half the current with double the voltage.
Bogle: Smart Beta is stupid

Shallowpockets
Posts: 1502
Joined: Fri Nov 20, 2015 10:26 am

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Shallowpockets » Sat Mar 09, 2019 8:22 am

Simple search on Amazon shows many voltage converters meant for foreign countries. Just plug into the 220 wall outlet. This way your lamp ca travel back to the U.S. and anywhere in the world.

myleaf
Posts: 66
Joined: Tue Sep 20, 2016 10:55 am

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by myleaf » Sat Mar 09, 2019 8:45 am

You can find 220V/240V bulbs that are identical to the common 120V incandescent light bulb. try lightbulbs dot com. Bulbrite 120060. The attic light next to my HVAC is wired for 220V/240V and i use this type of bulb. A standard 120V bulb in the socket exhibited the same behavior that the OP mentioned.
"Never met an electron I did not like"

The Wizard
Posts: 13356
Joined: Tue Mar 23, 2010 1:45 pm
Location: Reading, MA

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by The Wizard » Sat Mar 09, 2019 9:25 am

Shallowpockets wrote:
Sat Mar 09, 2019 8:22 am
Simple search on Amazon shows many voltage converters meant for foreign countries. Just plug into the 220 wall outlet. This way your lamp ca travel back to the U.S. and anywhere in the world.
Yes, I like this idea for around $35.
Probably the best idea for a traveling lamp...
Attempted new signature...

wilked
Posts: 1662
Joined: Thu Mar 24, 2011 1:50 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by wilked » Sat Mar 09, 2019 9:33 am

The Wizard wrote:
Sat Mar 09, 2019 9:25 am
Shallowpockets wrote:
Sat Mar 09, 2019 8:22 am
Simple search on Amazon shows many voltage converters meant for foreign countries. Just plug into the 220 wall outlet. This way your lamp ca travel back to the U.S. and anywhere in the world.
Yes, I like this idea for around $35.
Probably the best idea for a traveling lamp...
I would be cautious. Lots of poorly built units out there that will heat up / potentially cause a fire. Those are really a band aid solution and shouldn’t be used on a percent install (op made it sound like they want this lamp permanently in place).

The Wizard
Posts: 13356
Joined: Tue Mar 23, 2010 1:45 pm
Location: Reading, MA

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by The Wizard » Sat Mar 09, 2019 9:38 am

wilked wrote:
Sat Mar 09, 2019 9:33 am
The Wizard wrote:
Sat Mar 09, 2019 9:25 am
Shallowpockets wrote:
Sat Mar 09, 2019 8:22 am
Simple search on Amazon shows many voltage converters meant for foreign countries. Just plug into the 220 wall outlet. This way your lamp ca travel back to the U.S. and anywhere in the world.
Yes, I like this idea for around $35.
Probably the best idea for a traveling lamp...
I would be cautious. Lots of poorly built units out there that will heat up / potentially cause a fire. Those are really a band aid solution and shouldn’t be used on a percent install (op made it sound like they want this lamp permanently in place).
The first bunch of them on Amazon are rated for 2000 watts.
A 60 watt lamp should be safe indefinitely on one of those.
And OP wants this lamp to move between countries at times...
Attempted new signature...

Spirit Rider
Posts: 12235
Joined: Fri Mar 02, 2007 2:39 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Spirit Rider » Sat Mar 09, 2019 10:32 am

A voltage converter does not solve the fundamental problem that the lamp still would have a U.S. light bulb socket. A voltage converter is fine for vacations, not as a permanent solution. Same thing with plug adapters.

When it comes to electrical circuits and devices always do it the right way. As previously suggested replace the bulb socket, wiring and plug. The wiring does not technically need to be replaced, but you want a molded plug to the wiring.

The suggestion to use an inexpensive compatible lamp instead of a bulb socket and a wiring with a molded plug is a good idea. It is certainly easier to find and maybe less expensive. Then you just have to make sure the relative or someone that does it is comfortable/competent to do it.

jharkin
Posts: 2401
Joined: Mon Mar 28, 2016 7:14 am
Location: Boston suburbs

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by jharkin » Sat Mar 09, 2019 11:46 am

Electrical threads rank right up their with oil change threads in being painful to read...

Jack and computerguy got it right. 50Hz vs 60Hz is meaningless other than for devices that have AC synchronous motors.

If you want to use it in Europe you will need to:
* change the plug on the end of the power cord
AND
* Change the socket to accept a European base bulb

In the USA there are special order bulbs in Euro base styles made for 120v, but I have no idea if it works the other way around in Europe (worth looking into).


The wiring will be fine. Wiring capacity in Amps is determined by gauge and voltage rating is determined by the insulation. Typical USA lamp cord is 18ga (10 Amp) with 300v insulation. A US 60watt bulb would only draw 0.5A, a Euro 60w will draw 0.25A.... if you put an LED in it will be even less...

fogalog
Posts: 126
Joined: Sat Nov 07, 2015 11:31 am

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by fogalog » Sat Mar 09, 2019 12:30 pm

Caduceus wrote:
Sat Mar 09, 2019 4:42 am
In order for it to work safely, can we just use a bulb that's rated for 220v and plug it into the lamp, or do we have to re-wire the entire thing?
Basically yes. Just have your relative buy a standard (screw-mount) bulb and it will work. Most of Europe uses the same screw mount that is used in the US. The exception is the UK which sometimes uses a "bayonet mount" bulb. However, even there it is easy to find screw-mount bulbs.

The only caveat is that if the lamp is indeed "antique", the wiring might be old and degraded, in which case I would change it. It's pretty easy to do yourself.

Good luck!

Spirit Rider
Posts: 12235
Joined: Fri Mar 02, 2007 2:39 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Spirit Rider » Sat Mar 09, 2019 2:02 pm

fogalog wrote:
Sat Mar 09, 2019 12:30 pm
Caduceus wrote:
Sat Mar 09, 2019 4:42 am
In order for it to work safely, can we just use a bulb that's rated for 220v and plug it into the lamp, or do we have to re-wire the entire thing?
Basically yes. Just have your relative buy a standard (screw-mount) bulb and it will work. Most of Europe uses the same screw mount that is used in the US. The exception is the UK which sometimes uses a "bayonet mount" bulb. However, even there it is easy to find screw-mount bulbs.
Define "Basically"

Yes, both the US and Europe use Edison screw bases, but they are not the same. The US uses E26 and Europe E27. While E26 bulbs will fit in E27 sockets and vice versa. That does not mean they are fully interchangeable.

While the E26/E27 screw diameter is close at screw peak, there is a bigger difference at screw trough. Also, E27 has a meaningfully longer insulator and screw length. Therefore, an E26 bulb has reduced insulation and short circuit protection when used in an E27 socket. While there is less of a hazard in using an E27 bulb in an E26 base, why take chances with electrical safety.

If the OP does not want to change the lamp to an E27 base, there is another fully safe option. An LED is a DC device and many E26 LED bulbs offered for sale in the US have 90v - 240v/50Hz - 60Hz rectifiers in them even if they don't promote it. That allows the manufacturer to have one design worldwide and only use different bases for different markets.

So the OP can either buy themselves or have the relative buy an E26 LED bulb and use with full confidence. Then the relative can either use a plug adapter or replace with a compatible plug.

fogalog
Posts: 126
Joined: Sat Nov 07, 2015 11:31 am

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by fogalog » Sat Mar 09, 2019 2:46 pm

Spirit Rider wrote:
Sat Mar 09, 2019 2:02 pm
fogalog wrote:
Sat Mar 09, 2019 12:30 pm
Caduceus wrote:
Sat Mar 09, 2019 4:42 am
In order for it to work safely, can we just use a bulb that's rated for 220v and plug it into the lamp, or do we have to re-wire the entire thing?
Basically yes. Just have your relative buy a standard (screw-mount) bulb and it will work. Most of Europe uses the same screw mount that is used in the US. The exception is the UK which sometimes uses a "bayonet mount" bulb. However, even there it is easy to find screw-mount bulbs.
Define "Basically"

Yes, both the US and Europe use Edison screw bases, but they are not the same. The US uses E26 and Europe E27. While E26 bulbs will fit in E27 sockets and vice versa. That does not mean they are fully interchangeable.

While the E26/E27 screw diameter is close at screw peak, there is a bigger difference at screw trough. Also, E27 has a meaningfully longer insulator and screw length. Therefore, an E26 bulb has reduced insulation and short circuit protection when used in an E27 socket. While there is less of a hazard in using an E27 bulb in an E26 base, why take chances with electrical safety.

If the OP does not want to change the lamp to an E27 base, there is another fully safe option. An LED is a DC device and many E26 LED bulbs offered for sale in the US have 90v - 240v/50Hz - 60Hz rectifiers in them even if they don't promote it. That allows the manufacturer to have one design worldwide and only use different bases for different markets.

So the OP can either buy themselves or have the relative buy an E26 LED bulb and use with full confidence. Then the relative can either use a plug adapter or replace with a compatible plug.
Thanks for the expanded detail - hence why I said "basically". :happy

Personally, I still think the larger risk is from "antique" wiring.

Starfish
Posts: 1546
Joined: Wed Aug 15, 2018 6:33 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Starfish » Sat Mar 09, 2019 3:29 pm

How did you manage to plug in the lamp in the 220V outlet? did you use an adapter?

The lamp doesn't require any rewiring if the wire insulation is in good shape, only a different bulb and socket if necessary. However the insulation could have major issues. As one who had tens of shocks at 220V as a kid, I can tell you they are no fun if your lamp is made of metal. And of course there is the fire hazard.
I am just amazed it would cross your mind to plug in a lamp with a 110V bulb ion a 220V network.

dbr
Posts: 31236
Joined: Sun Mar 04, 2007 9:50 am

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by dbr » Sat Mar 09, 2019 3:50 pm

The Wizard wrote:
Sat Mar 09, 2019 5:21 am
Caduceus wrote:
Sat Mar 09, 2019 5:12 am
Yes, so this is exactly what I don't understand. Are all lamp wirings (this is a vintage lamp) capable of bearing different voltages? And so it's just the bulb I need to change?
That is basically correct, especially for an incandescent bulb which I assume you are using.

Technically you need heavier wiring when drawing higher current, but 240 volts draws 1/2 the current for the same watt bulb as 120 volts, so US wiring will be fine.

Also technically, higher voltages need better insulation to prevent arcing and shorts, but 240 volts isn't that high. Most consumer wiring insulation seems to be rated for up to 600 volts from what I've seen...
Yes, but I would still rewire a vintage lamp due to age and deterioration. At the same time one can be sure things are up to current standards. It could be one should replace the socket and lampswitch on the same grounds -- not voltage but age and use.

In the case of 120V US polarity is an issue. I don't think most 240V circuits in other countries have a polarity. New manufacture components in the US are coded for correct polarity.

inbox788
Posts: 6697
Joined: Thu Mar 15, 2012 5:24 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by inbox788 » Sat Mar 09, 2019 4:34 pm

Caduceus wrote:
Sat Mar 09, 2019 5:12 am
My goal is to have a lamp that can work anywhere in the world. Is the best solution to replace the wire/socket for the highest possible voltage - would it then work in an area with a low voltage?
That's a strange requirement. Do you regularly travel with the vintage lamp?

Simple solution is to match the voltage requirement to the country, so if it's a 240 volt country, make the lamp 240v capable as others have suggested.

A stupid universal solution is something like this: https://www.amazon.com/Onite-20-US24USB ... 00QX096L0/

which could be plugged into:

USB Wall Charger (US; elsewhere with plug adapter)
https://www.amazon.com/AmazonBasics-One ... 0773JFWDC/

Universal All in One Worldwide Travel Adapter Wall (if you travel with your lamp a lot)
https://www.amazon.com/NEWVANGA-Interna ... B01FO4W5W2

Australia New Zealand AU Plug Wall Charger (or similar specific plug for the country you plan to use it in)
https://www.amazon.com/interface-Adapte ... 07LBY4735/

User avatar
oldcomputerguy
Moderator
Posts: 6811
Joined: Sun Nov 22, 2015 6:50 am
Location: In the middle of five acres of woods in East Tennessee

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by oldcomputerguy » Sat Mar 09, 2019 4:49 pm

Shallowpockets wrote:
Sat Mar 09, 2019 8:22 am
Simple search on Amazon shows many voltage converters meant for foreign countries. Just plug into the 220 wall outlet. This way your lamp ca travel back to the U.S. and anywhere in the world.
It's important to note the difference between a "voltage converter" (which features circuitry that accepts the incoming 220 volt feed and produces a 110v feed suitable for US appliances) and an "adapter plug" that just adapts the configuration of the foreign outlet to the U.S. pins on your existing power devices. The latter does nothing to convert the voltage, it just bridges the power across physically incompatible plug configurations.
"I’ve come around to this: If you’re dumb, surround yourself with smart people; and if you’re smart, surround yourself with smart people who disagree with you." (Aaron Sorkin)

Starfish
Posts: 1546
Joined: Wed Aug 15, 2018 6:33 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Starfish » Sat Mar 09, 2019 6:00 pm

For a real voltage converter you have to make sure it can supply the current. I assume nobody puts in a vintage lamp an LED bulb. When I take my lamp out of my luggage after a long flight I want the warm light of incandescence.

Topic Author
Caduceus
Posts: 2133
Joined: Mon Sep 17, 2012 1:47 am

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Caduceus » Sat Mar 09, 2019 7:37 pm

Thank you, everyone. I think what I will do, just to be extra safe, is just get someone to help me re-wire everything and put in the higher voltage socket and bulb.

Short of using (1) a voltage converter or (2) and E26 LED bulb, is the answer to my question of whether I can re-wire the lamp to work with different voltages a No? I read all the replies on this thread but still can't understand the answer. I thought if I re-wired it to the higher voltage, it would work safely still in the U.S. when it draws a lower voltage, just that the bulb would be dimmer. (Or does it not work that way?)

Why doesn't my laptop have any problems traveling between countries then? I have to use a plug adaptor so it can fit into the socket, but I have zero issues bringing my laptop anywhere. Basically, what I want to do is make my lamp as functional as my laptop - only change the plug adaptor.

neilpilot
Posts: 2914
Joined: Fri Dec 04, 2015 1:46 pm
Location: Memphis area

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by neilpilot » Sat Mar 09, 2019 7:40 pm

Caduceus wrote:
Sat Mar 09, 2019 7:37 pm
Thank you, everyone. I think what I will do, just to be extra safe, is just get someone to help me re-wire everything and put in the higher voltage socket and bulb.

Short of using (1) a voltage converter or (2) and E26 LED bulb, is the answer to my question of whether I can re-wire the lamp to work with different voltages a No? I read all the replies on this thread but still can't understand the answer. I thought if I re-wired it to the higher voltage, it would work safely still in the U.S. when it draws a lower voltage, just that the bulb would be dimmer. (Or does it not work that way?)

Why doesn't my laptop have any problems traveling between countries then? I have to use a plug adaptor so it can fit into the socket, but I have zero issues bringing my laptop anywhere. Basically, what I want to do is make my lamp as functional as my laptop - only change the plug adaptor.
You laptop, as well as most modern electronics including you phone charger, are dual voltage. Only a plug converter is required.

Topic Author
Caduceus
Posts: 2133
Joined: Mon Sep 17, 2012 1:47 am

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Caduceus » Sat Mar 09, 2019 7:43 pm

neilpilot wrote:
Sat Mar 09, 2019 7:40 pm
Caduceus wrote:
Sat Mar 09, 2019 7:37 pm
Thank you, everyone. I think what I will do, just to be extra safe, is just get someone to help me re-wire everything and put in the higher voltage socket and bulb.

Short of using (1) a voltage converter or (2) and E26 LED bulb, is the answer to my question of whether I can re-wire the lamp to work with different voltages a No? I read all the replies on this thread but still can't understand the answer. I thought if I re-wired it to the higher voltage, it would work safely still in the U.S. when it draws a lower voltage, just that the bulb would be dimmer. (Or does it not work that way?)

Why doesn't my laptop have any problems traveling between countries then? I have to use a plug adaptor so it can fit into the socket, but I have zero issues bringing my laptop anywhere. Basically, what I want to do is make my lamp as functional as my laptop - only change the plug adaptor.
You laptop, as well as most modern electronics including you phone charger, are dual voltage. Only a plug converter is required.
Can lamps be turned into dual voltage appliances? (That was the word I needed!) Or is (1) voltage converter and (2) E26 bulb the only options?

User avatar
oldcomputerguy
Moderator
Posts: 6811
Joined: Sun Nov 22, 2015 6:50 am
Location: In the middle of five acres of woods in East Tennessee

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by oldcomputerguy » Sat Mar 09, 2019 7:47 pm

Caduceus wrote:
Sat Mar 09, 2019 7:37 pm
Why doesn't my laptop have any problems traveling between countries then? I have to use a plug adaptor so it can fit into the socket, but I have zero issues bringing my laptop anywhere.
Look at the power supply for your laptop. It probably indicates somewhere in the fine print on the power supply that it will work with a wide range of input voltages. The circuitry in the power supply handles the wide disparity of input voltages seamlessly, and regulates it down to the DC voltage needed by your laptop. Incandescent light bulbs are much, much simpler and are designed to work on a specific input voltage. I’m not familiar enough with LED light bulbs to say whether the same is true with them.
"I’ve come around to this: If you’re dumb, surround yourself with smart people; and if you’re smart, surround yourself with smart people who disagree with you." (Aaron Sorkin)

Topic Author
Caduceus
Posts: 2133
Joined: Mon Sep 17, 2012 1:47 am

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Caduceus » Sat Mar 09, 2019 7:50 pm

oldcomputerguy wrote:
Sat Mar 09, 2019 7:47 pm
Caduceus wrote:
Sat Mar 09, 2019 7:37 pm
Why doesn't my laptop have any problems traveling between countries then? I have to use a plug adaptor so it can fit into the socket, but I have zero issues bringing my laptop anywhere.
Look at the power supply for your laptop. It probably indicates somewhere in the fine print on the power supply that it will work with a wide range of input voltages. The circuitry in the power supply handles the wide disparity of input voltages seamlessly, and regulates it down to the DC voltage needed by your laptop. Incandescent light bulbs are much, much simpler and are designed to work on a specific input voltage. I’m not familiar enough with LED light bulbs to say whether the same is true with them.
Ahh, OK! I understand (finally!) Thank you 8-)

No dual voltage lamp for us then. Thanks everyone.

The Wizard
Posts: 13356
Joined: Tue Mar 23, 2010 1:45 pm
Location: Reading, MA

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by The Wizard » Sat Mar 09, 2019 8:05 pm

Starfish wrote:
Sat Mar 09, 2019 6:00 pm
... When I take my lamp out of my luggage after a long flight I want the warm light of incandescence.
This is getting to be funny.
The very idea of flying around the world to all the former British colonies (for instance) one place at a time.
Upon arrival at each new place, first set up the vintage lamp for ambience, then procure a stiff gin cocktail to be consumed with little finger askew.
I'm all set with this plan...
Attempted new signature...

whomever
Posts: 894
Joined: Sat Apr 21, 2012 5:21 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by whomever » Sat Mar 09, 2019 8:14 pm

" I’m not familiar enough with LED light bulbs to say whether the same is true with them. "

Most that I see are labeled 120V, but some have wider ranges, e.g.:

https://www.amazon.com/CMC-LED-Light-La ... B01FPOBI3I

One of those is likely the simplest solution to the OP's problem.

You can also get 220V incandescent bulbs in the normal form factor - I have one in a drill press that is wired 220 for the motor, and no neutral. It looks identical to a normal 110 bulb, except for the fine print saying 220.

The Wizard
Posts: 13356
Joined: Tue Mar 23, 2010 1:45 pm
Location: Reading, MA

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by The Wizard » Sat Mar 09, 2019 8:15 pm

Caduceus wrote:
Sat Mar 09, 2019 7:43 pm
...Can lamps be turned into dual voltage appliances?
Incandescent, no.
But as someone else mentioned, an LED bulb *might* actually be dual voltage capable, since they have embedded electronics to convert AC to low voltage DC.
Are you okay with an LED bulb in this vintage traveling lamp?
Attempted new signature...

dbr
Posts: 31236
Joined: Sun Mar 04, 2007 9:50 am

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by dbr » Sat Mar 09, 2019 8:23 pm

The Wizard wrote:
Sat Mar 09, 2019 8:15 pm
Caduceus wrote:
Sat Mar 09, 2019 7:43 pm
...Can lamps be turned into dual voltage appliances?
Incandescent, no.
But as someone else mentioned, an LED bulb *might* actually be dual voltage capable, since they have embedded electronics to convert AC to low voltage DC.
Are you okay with an LED bulb in this vintage traveling lamp?
They exist. One also needs correct socket. http://images.philips.com/is/content/Ph ... oltage.pdf

User avatar
Epsilon Delta
Posts: 8090
Joined: Thu Apr 28, 2011 7:00 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Epsilon Delta » Sat Mar 09, 2019 8:46 pm

For an incandescent bulb doubling the voltage does not double the current. It increases it by 40% or so. The white hot filament's resistance has a positive temperature coefficient. This actually matters because the voltage is not well controlled and will vary between say 100V and 130V. If the light output were purely V^2/R you'd probably notice. The imprecise voltage is one reason the US standard is variously called 100, 110, 115, 120 and 125.

Also the insulation and wire gauges for lamp cords are limited by mechanical properties (e.g. strength and abrasion resistance) rather than voltage and current. You could make them thinner to carry the current, but they'd break when you step on them. That is why you can use the same cord for 120V and 230V, and you use the same cord for an LED as an incandescent.

Jack FFR1846
Posts: 10800
Joined: Tue Dec 31, 2013 7:05 am
Location: 26 miles, 385 yards west of Copley Square

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Jack FFR1846 » Sat Mar 09, 2019 8:53 pm

Ignoring the plug incompatibility, if the socket and bulb are changed to accept a 220V bulb, the lamp will work anywhere. However, it will not produce as much light at lower voltages in places like the US or especially Japan.
Bogle: Smart Beta is stupid

Spirit Rider
Posts: 12235
Joined: Fri Mar 02, 2007 2:39 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Spirit Rider » Sat Mar 09, 2019 9:43 pm

The Wizard wrote:
Sat Mar 09, 2019 8:15 pm
Are you okay with an LED bulb in this vintage traveling lamp?
There are actually Antique LED Filament Bulbs. You can get Edison, Victorian, Globe and A19 bulb shape filament LED bulbs.

However, I don't know if any of them are dual voltage range capable. Typically, niche markets don't get all the enhanced capabilities.

User avatar
Epsilon Delta
Posts: 8090
Joined: Thu Apr 28, 2011 7:00 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Epsilon Delta » Sat Mar 09, 2019 11:05 pm

Spirit Rider wrote:
Sat Mar 09, 2019 9:43 pm
The Wizard wrote:
Sat Mar 09, 2019 8:15 pm
Are you okay with an LED bulb in this vintage traveling lamp?
There are actually Antique LED Filament Bulbs. You can get Edison, Victorian, Globe and A19 bulb shape filament LED bulbs.

However, I don't know if any of them are dual voltage range capable. Typically, niche markets don't get all the enhanced capabilities.
I'd expect dual voltage to be slightly more likely in niche products.

Very few customers want dual voltage capability, lots of manufacturing plants and all logistic chains want them.

For high volume stuff it may be worth paying the costs of dual production and distribution. Optimizing for each market to save few cents in components per unit. For low volume, high end stuff it's often cheaper to just have one version for all markets.

suemarkp
Posts: 231
Joined: Sun Nov 12, 2017 8:18 pm
Location: Kent, WA

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by suemarkp » Sat Mar 09, 2019 11:31 pm

One other detail if you change the plug on the lamp. Polarity does matter. Typically, one of the two power wires is grounded (also called a neutral) at the service entrance. In the US, it is the white wire in a cable or cord and the black one is the "hot" wire. The hot wire needs to go to the bottom of the edison socket and the grounded one needs to go to the threaded part of the socket. If you get this backwards, you could be shocked when screwing in a new bulb if the lamp is on and you're touching the threads on the base of the bulb (not easy to do but possible if you're guiding it in with the other hand). If you look carefully at a "zip cord" lamp cord, the edge of one of the two wires will have ridges. I think that is the grounded one, but not sure.

Wire colors in other countries will not be the same as the US (our white may be blue, and our black may be brown). But you'll need to know which prong of the power plug gets which wire. This can be determined with a meter but this may be above your skill level.

Moving electrical items between countries is a pain, and very difficult to do if you're selling it (many places require it be listed which means getting the grounding correct, using correct colors, etc). It is getting easier with many items that now take 90V-250V input (they are labeled as such and have wide voltage switching power supplies). The cord adapter and LED bulb solution is probably best if it will take the 250V and not fail, and you can find one of the style and color temperature you want (probably 2700K if you like old school incandescent lamp color).

One final note - in the US you can buy 130V lamps. These typically have a much longer life than a 120V or 125V lamp. But they are rather orangish. If you could buy a 150V bulb, they would be very orange. If you try a 250V European incandescent bulb in the US using 120V, it is going to be quite dim and very orange red (output will be 1/4 the normal lamp power).
Mark | Kent, WA

criticalmass
Posts: 1403
Joined: Wed Feb 12, 2014 10:58 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by criticalmass » Sun Mar 10, 2019 12:36 am

suemarkp wrote:
Sat Mar 09, 2019 11:31 pm
One other detail if you change the plug on the lamp. Polarity does matter. Typically, one of the two power wires is grounded (also called a neutral) at the service entrance. In the US, it is the white wire in a cable or cord and the black one is the "hot" wire. The hot wire needs to go to the bottom of the edison socket and the grounded one needs to go to the threaded part of the socket. If you get this backwards, you could be shocked when screwing in a new bulb if the lamp is on and you're touching the threads on the base of the bulb (not easy to do but possible if you're guiding it in with the other hand). If you look carefully at a "zip cord" lamp cord, the edge of one of the two wires will have ridges. I think that is the grounded one, but not sure.
Polarity matters in countries like USA and UK, but less so in countries like France. There, two conductor plug connectors to the wall don't have the polarity feature that you are used to in USA, where one conductor /plug is wider to enforce only plugging it in one way. (You can only plug in a three conductor plug in one direction, because the earth plug sticks OUT from the wall, but lamps typically won't use the earth plug).

In the USA this is done so the switch turns off the hot wire (the one that would shock you if you touched it), and also the hot conductor at a light bulb base is all the way at the bottom, not the one with the threads that you could touch when screwing in a bulb.

In countries like France, the switches often turn off BOTH wires (double pole) because they don't worry which one is hot or neutral. Wiring colors are completely different in Europe than USA where things are pretty well standardized. The one thing that IS standardized in Europe is that ground wires are green/yellow or sometimes just green. Live is supposed to be red or brown, but sometimes is black like USA. Switched wires might be orange, violet, red, or brown. Neutral should be blue, but don't bet your life on it. Neutral isn't always the same potential as ground.

So bottom line is:
  • Wiring *should* be okay for 220 volts, because most lamp wiring would be suitable for up to 400 or 600 volts, but check the spec printed on the wire.
  • The amount of current drawn by a 220 volt light bulb is less than a 110 volt light bulb of the same wattage, so the wire should be okay for the current.
  • Frequency does not matter for incandescent bulbs, but can matter very much for (non-universal) motors and potentially other forms of light.
  • Polarity could be an issue for switching to ensure the hot wire is turned off. Best to use a double pole switch.
  • Don't assume USA specs and practices when working with wiring (house or lamp or appliance) in other continents.

boomer_techie
Posts: 242
Joined: Fri Jan 18, 2019 6:47 am

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by boomer_techie » Sun Mar 10, 2019 3:08 am

Caduceus wrote:
Sat Mar 09, 2019 7:37 pm
Why doesn't my laptop have any problems traveling between countries then? I have to use a plug adaptor so it can fit into the socket, but I have zero issues bringing my laptop anywhere. Basically, what I want to do is make my lamp as functional as my laptop - only change the plug adaptor.
Your laptop has $100 of high tech electronics (well, ... $10 today due to manufacturing in cheap countries) to handle a range of voltages. Lamp manufacturers only want to spend a few pennies for a bulb socket.

criticalmass
Posts: 1403
Joined: Wed Feb 12, 2014 10:58 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by criticalmass » Sun Mar 10, 2019 8:58 am

Caduceus wrote:
Sat Mar 09, 2019 7:37 pm
Thank you, everyone. I think what I will do, just to be extra safe, is just get someone to help me re-wire everything and put in the higher voltage socket and bulb.

Short of using (1) a voltage converter or (2) and E26 LED bulb, is the answer to my question of whether I can re-wire the lamp to work with different voltages a No? I read all the replies on this thread but still can't understand the answer. I thought if I re-wired it to the higher voltage, it would work safely still in the U.S. when it draws a lower voltage, just that the bulb would be dimmer. (Or does it not work that way?)

Why doesn't my laptop have any problems traveling between countries then? I have to use a plug adaptor so it can fit into the socket, but I have zero issues bringing my laptop anywhere. Basically, what I want to do is make my lamp as functional as my laptop - only change the plug adaptor.
This is because your laptop actually operates/accepts low voltage DC, typically between 5-15 volts. The power supply converts the mains voltage to the laptop input voltage. It can automatically handle between ~100-240 volts and 50-60 Hz.

Once converted to DC, the output is 0 Hz, but frequency is a consideration for transformers that change voltage. E.g. Lower frequencies will produce more heat in a (voltage) transformer, everything else being equal.

Many electronics today incorporate these power supplies because this means only one final product design is needed to sell worldwide, and as an extra bonus, traveling is simplified.

Three cheers for electrical engineering!

But: Don't be lulled into false security that everything accepts all mains voltages. Always read labels for acceptable input electricity specs before connecting to electricity in a different region than a device is intended for.
Last edited by criticalmass on Sun Mar 10, 2019 8:08 pm, edited 1 time in total.


User avatar
Epsilon Delta
Posts: 8090
Joined: Thu Apr 28, 2011 7:00 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Epsilon Delta » Sun Mar 10, 2019 11:52 am

Auto switching is the wrong description for most universal power supplies. Most of them simply have a wide input range. They will be marked something like 100V-250V AC. Which means they can run on anything between those limits. Many of them will run on DC as well. An auto-switching power supply will be marked something like 110V/220V. It will run on nominal 110V or 220V, but if is not designed to work with on say 170V. This is usually not a problem because it is hard to find 170V coming out of the wall.

There are older designs with a manual switch to select 110V/220V. It is the users job to set the switch before plugging it.

Note that a "switching power supply" and an "auto-switching power supply" are not the same thing. "Switching power supply" describes how the power supply turns input power into output power. "Auto-switching" means there is a circuit that detects the input voltage and flips the equivalent of the manual switch found in older designs.

User avatar
Epsilon Delta
Posts: 8090
Joined: Thu Apr 28, 2011 7:00 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Epsilon Delta » Sun Mar 10, 2019 12:11 pm

boomer_techie wrote:
Sun Mar 10, 2019 3:08 am
Lamp manufacturers only want to spend a few pennies for a bulb socket.
For a consumer Edison sockets are more expensive than many LED light bulbs. Probably not quite true for lamp manufacturers. Sockets are also less reliable than bulbs. I have a lamp that is now on it's third socket with the same LED bulb. Which is kind of perverse.

If we were starting from scratch we would not have Edison sockets, the bulb would be mechanically mounted with proper threads (or glue) and use screw terminals as found on better plugs and the backs of wall sockets.

sco
Posts: 923
Joined: Thu Sep 24, 2015 2:28 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by sco » Sun Mar 10, 2019 11:55 pm

I read this as "My Lamb Exploded-....."

Spirit Rider
Posts: 12235
Joined: Fri Mar 02, 2007 2:39 pm

Re: My lamp exploded - can I re-wire it so that it will work with different voltages?

Post by Spirit Rider » Mon Mar 11, 2019 12:27 am

sco wrote:
Sun Mar 10, 2019 11:55 pm
I read this as "My Lamb Exploded-....."
Metaphorically speaking, that doesn't happen at my house for six weeks.

Post Reply