Christmas lights and Ohms law sorta question

rbh

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Well I found my 1940-50ish bubble lights but now I need to change out some of the bulbs. These are a screw in style candelabra/mini light E-10? The strand is the old #1 wire return, so if the bulb goes you are checking each bulb for continuity.
But here is the question, 9 bulb string they do not make the bulbs anymore so I need to source them locally (E -bay will take to long).

120vac divided by the 9 bulbs is 13.3--The bulb I can get is a 14.9V 0.2 amp and I need a minimum 5 watt bulb are these going to work?
 

fhhuber

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14 X .2 = 2.8 watts... if it was getting the 14 v.

If you replace all with the same type it will be a dim string. If you replace just the bad ones the new bulbs will not be the same brightness as the old. The other bulbs being appx 1/2 the resistance... you'd probably be blowing the new bulb(s) If just one or 2 out of 9. (but you'd probably get the 5 watts from them for a few seconds)

Without pulling out paper and pencil... I expect that at appx 6 new and 3 old you'd be running at the 14.8v drop in the new and half wattage in the old.

Its looking like time to retire the string until you find the right bulbs.
 

rbh

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Thanks, this is APITA, but these are old lights with the mini screw in base about the size of a BIC pen in diameter.
I need 5-6 Watts due to the fact that the bulb heats the tube with the liquid in it to make the bubbles (Noma bubble lights circa 1940-50)

The newer ones have the E12 bulb bases I need the E10
 

sangerwaker

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Don't you need a 120V bulb? 14.4V bulbs will last about 1/10 of a second at 120V. Will be very tough to find locally. I'd suggest ordering online from a reputable seller and ship next day air.
 

rbh

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I looked through those sites but I need E-10 bulbs
 

sam am I

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Hmmmm, never seen an E-10 14'V'ish rated for that high of heat. Got a picture?

Maybe similar to these?

http://www.multilightholland.nl/e10-...-5watt-vl.html

Course running 9 of these in series, they'd would cool down less than 5W @120....Weird. The string isn't series-parallel is it? Or it's just using 5W at 24V bulbs at 14V and is like little cooler than 5W, maybe running like 4'ish watts each.
 
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rbh

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I am thinking that those bulbs would work, the original bulbs came with a flat top but that does not matter because they do not make them anymore.

I just need to see what I can source locally using the 120 VAC divided by 9 sockets in series-available bulbs are 14.9 V with a 0.2 amp draw?

Does the 0.02 get me the 5 watts I require?

Thanks Guys
 

gm280

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Bulbs like that really don't have to be exact voltage. In other words if you could fine 12 volt bulbs in the correct base design and wattage you need, the mere little voltage different will still work. The filaments don't care how precise the voltage is. In fact I bet with 9 in a series string, they would look perfect.
 

sam am I

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I am thinking that those bulbs would work, the original bulbs came with a flat top but that does not matter because they do not make them anymore.

I just need to see what I can source locally using the 120 VAC divided by 9 sockets in series-available bulbs are 14.9 V with a 0.2 amp draw?

Does the 0.02 get me the 5 watts I require?

Thanks Guys

Power = Current * Voltage

If you have a bulb that draws .2A at 14-15V, you'd have roughly 3W. And if you take 9 of them in series with 120V, with all things being linear......Heat will drop just a tad bit at 120/9 = 13.3V

Probably work fine, might just take a little more time to get bubbling. I recall snapping them sometimes to get going too!!

Worse case, you could light a fire and boil some water for Cocoa....:)
 
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rbh

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Well, I just made the decision to buy the E-Bay bulbs and by the time they get here it will be Jan1 2016 and the ten bulbs will be 50 bucks AHHHHH.
$14.99 for ten then add the 30 percent for exchange rate and shipping GRRRR-but at least I will have the right bulbs to fix the 4 burnt out and spares.

Now my mom calls and says she has spare christmas bulbs that will fit the sockets if anymore bubblers burn out, I bet you remember the ones with the thick paint on the bulb and would burn down a tree if you left them on long enough?
 

Volphin

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Oh wow! I remember those bulbs! Mom had some on the tree along with those big honkers! I loved how bright the trees were back then.
 

dpoff

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Unless it`s for sentimental reasons, buy a new set. I bought some a few years ago after seeing them in a local store and they work like the old ones.
 

rbh

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Oh wow! I remember those bulbs! Mom had some on the tree along with those big honkers! I loved how bright the trees were back then.
Ya they are pretty cool, thats why I love the old bubble lights-they have memories that take me back 45 years.

Dpoff The new ones are OK, but well you know, there is a difference-.LOL- once I get the bulbs its an easy fix just a bit inconvenience.
 
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