220v light bulb

[tuberider]

I have a 12v DC to 220v 50 Hz AC 250w inverter and I want test.I want to take two 120v AC light bulbs and put them in series to make one 220v bulb. I was going to use 200w bulbs. Is that possible?

[Wotname]

Yes and No.

Yes to two 120VAC is series but no to 200W bulbs. You will need to use 100W or 125W bulbs.

[masonc]

Originally Posted by tuberider

I have a 12v DC to 220v 50 Hz AC 250w inverter and I want test.I want to take two 120v AC light bulbs and put them in series to make one 220v bulb. I was going to use 200w bulbs. Is that possible?

2 x 120v tungsten bulbs in series will work fine to test an inverter, yes. Use a meter to test the actual output voltage when loaded with the lamps.

[skipmac]

Originally Posted by Wotname

Yes and No.

Yes to two 120VAC is series but no to 200W bulbs. You will need to use 100W or 125W bulbs.

Why can't he use 200W bulbs? In series that would add to 400W but don't understand why that would be a problem.

[Sailmonkey]

Originally Posted by skipmac

Why can't he use 200W bulbs? In series that would add to 400W but don't understand why that would be a problem.

Because it's a 250 watt inverter.

[Wotname]

^^

[skipmac]

Originally Posted by Sailmonkey

Because it's a 250 watt inverter.

Duh!!

Message to self. Read more carefully or wait until after a second cup of coffee.

[a64pilot]

I don't think wiring light bulbs in series will double their voltage requirement, it sounds logical, but remember way back when you were a kid, Christmas tree lights were series connected bulbs, one went out and the whole string wouldn't light.
Well, I don't think that long string of lights used 1000V bulbs. I think they were all 110V bulbs, but they were wired in series.

[transmitterdan]

Putting 2 120V light bulbs in series and powering them from 220V will put about the same amount of power into each bulb as they are rated. So 2 100W bulbs will draw about 200W. If you use 2 200W bulbs they will draw a total of about 400W.

[transmitterdan]

Originally Posted by tuberider

I have a 12v DC to 220v 50 Hz AC 250w inverter and I want test.I want to take two 120v AC light bulbs and put them in series to make one 220v bulb. I was going to use 200w bulbs. Is that possible?

No. This will draw 400W and overload the inverter. Try using 2 60W bulbs which will draw about 120W. Most cheap inverters are only really good for about 1/2 the name plate rating. At full power they quickly overheat.

[a64pilot]

So series will work for bulbs? They are just resistors so I don't see why not, but can't explain the 1950's Christmas lights

[rwidman]

Originally Posted by a64pilot

I don't think wiring light bulbs in series will double their voltage requirement, it sounds logical, but remember way back when you were a kid, Christmas tree lights were series connected bulbs, one went out and the whole string wouldn't light.
Well, I don't think that long string of lights used 1000V bulbs. I think they were all 110V bulbs, but they were wired in series.

You should be asking the electrical questions, not answering them.

Two 120 volt lamps wired in series is the equivalent of one 240 volt lamp.

The Christmas tree lamps were low voltage lamps that added up to 120 volts. For example, ten twelve volt lamps wired in series would require 120 volts to provide each lamp with twelve volts. Twenty six volt lamps would work as well.

[donradcliffe]

Unless you really want to use your inverter for 250 watts, I would not test it at more than half its rating. The ratings are optimistic, and you will be drawing 20 amps on the 12v side, way more than a cigarette lighter plug can handle.

[masonc]

Originally Posted by tuberider

I was going to use 200w bulbs. Is that possible?

2 x 200W is 400W, you have a 250W inverter. The math doesn't look good.
Use 2 x 100w 120V tungsten light bulbs to test the inverter. Chances are the 250W rating is optimistic, 200W will run it pretty much flat out. Chances are the rated duty cycle is about 15%, so you had better only run it for a couple of minutes at 200W.

[senormechanico]

Further, if you put two lights in series, they must both be the same wattage rating.
If you put for example, a 25 watt and a 100 watt in series, the 25 watt light would be dropping the most voltage and would burn out before the 100 watt bulb even warmed up much if at all.