Remote Living > Lighting

Christmas Lighting

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richhagen:
I would recommend placing resistance in series with the LED's as when they fail, they often do so by shorting.  If you have nothing to limit the current, your whole string would likely fail with the first LED.  I like Nando's evaluation.  If you can get an efficient switching 12 volt (or other low voltage) supply, like from an old lap top or such, use that to provide your 12 volts, and then run your LED's in series with a resistor off of that (V = I*R).  
The color of light given off by an LED is generally a function of the voltage drop.  Blue light has a higher frequency than red light. The energy in a photon of light is equal to the frequency of the light times a constant value or ratio, which is called Plank's Constant.  Since the speed of light is the same for all frequencies, the energy could also be described as being equal to Planck's Constant multiplied by the Speed of light and divided by the wavelength.   Thus a photon of blue light has more energy than a photon of red light.  Energy is conserved across the P/N junction.  so the voltage drop for a red LED is less, often about 1.7 volts compared with a blue, often about 3.6 volts.  White LED's are actually blue or ultraviolet leds with a phosphor coating which absorbs most of the generated wavelength and re-transmits the energy as a combination of wavelengths of lower energy.  Think of a rainbow, the light wavelengths have more energy as you travel from the red to the purple side.  LED's follow the exact same pattern, with highest voltage drops on the ultraviolet end and lowest on the infrared end.  The differences with LED's are that there is internal resistance in the LED itself, the amount depending upon how it is made, which can cause a higher voltage to be required across the leads than is actually required to generate the LED's light frequency for any practical amount of current.    Rich Hagen

nothing to lose:
Hmm, you may have a point, I don't like those "IF one goes out they all go out" old time Christmas lights, don't want the leds to all fry if one goes out, so maybe the resistor would be a good saftey measure for that. SO far I haven't needed it, YET.
As for the led colors. I don't know what he has for the light string, but mine were colored plastic and most likely all the same led inside. Maybe all whites shining though red or green or blue plastic. Really just a little glowing light inside plastic is all they were, but all one piece, not like an led with a plastic cover over it.
I do have real leds that all are clear when off, then some are UV, red, ect.. when lit.

Kinda hard to tell whats what if they get mixed unless I put power to them. Definantly not the same thing as the Christmas lights leds I had but more like whats being mentioned here probably.

ghurd:
You are 'mixing apples and oranges'.

it will take a balancing act to get the parts to work in series.

One is current driven, one is voltage driven. Simplified.

G-

DRAYCO:
actually, i wasn't totally talking about what everyone answered my question to about.
I was talking about, how the fact i've got LED lights, and that they are fixed bulbs, so there is no putting in those spinny things or those additional light up thingys for the tree,  only the traditional lights can do that,  and i was wanting to know what to do, to take a traditional set, and cut it down to only having 5 bulbs on it, 5 outlets more or less, becasue i'll be putting those spinny and lighty up things into them, and spreading them around the tree
so i figured someone here could tell me, what i would need to do, i figure personally i need something to make a load so that those only 5 bulbs feel as if there are 45 more, but there isnt,  there is some sort of dummy load thing there instead.  
does that clear things up a little ?

nothing to lose:
OH.
Well I don't know what you would do then for a dummy load?
If your talking the standard mini twinkle type lights everyone normally uses, they are usually 1.5V or the super brights I think are 2V.

I think if it were me I would just run those 5 lights on rechargable batteries or a wallwort transformer. They sell those strings of about 5 and 10 lights that run on batteries.

 The little spinning motors to rotate ornaments are the same volts also since they plug into the light sockets normally.
I don't have any handy to test with but I think you could just cut off 6 sockets/lights already wired in a row and use a 12V wallwort transformer wired to the set. If you try that, run it for several hours (or all day) laying out safe and check for any heat problems with wires or the wallwort. I do that kind of stuff all the time with twinkle lights but not exactly what your doing so test first. You might want to try 8 lights first incase you have the 1.5V bulbs, if they are dim then cut off one at a time till you get the correct brightness. Or just test 1 bulb first on a 1.5v battery and see how bright it lights.
Of course the wallwort transformers come in all kinds of powers. If you have one laying around from a junk scanner or printer it should probably work ok, just match the volts for the lights to the transformer in case you have 9V or 12V, if it can run a scanner/printer it should have the amps to run a few lights. Beware of those wallworts for things like cheap speakers and such, they are often low power and may NOT run the lights. It should have the amps  or miliamps listed with the volts on it.
Anyway that's what I would do, either rechargable batteries or a good wallwort transformer.

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