Instructables

converting 110v christmas lights to 12v

In a web search looking for 12v Christmas lights to run off my small solar system, I found this; http://www.fly.net/~thundt/xmas12v.htm

This looks very straight forward and easy enough to do.
Has anyone here tried this?

I bought a small set of solar powered at Target ($14.95). Way under powered and last only a few hours. It's going back today!

This looks like a way to get brighter, longer lasting lights and I don't have to run my converter. My 160 AH battery should power it up nicely, I would think...

Think I found a project for this afternoon!

gracedan10 months ago
This question was asked 2 years ago.. now it is not a problem at all.
look at http://christmaslightscape.blogspot.com/ ...... look at MODIFY tab
It gives complete instructions on modifying LED lights onto any DC voltage and fitting a controller to give zingy effects.
The author will give technical advice if you email the light details to him.

Now go and have more fun!
There are some 12v xmas lights sold at the dollar tree if im decently sure
guyfrom7up5 years ago
couple things: since your running solar, you should try LEDs instead of lightbulbs to save more electricity. if you do use LEDs, remember, you need individual resistors for each set of series, I'm not sure how they are manufactured, but they are probably a whole bunch in series, then a tiny resistor at the end, so you'll have to add your own.
olddawg (author)  guyfrom7up5 years ago
Thank You!
I just came back from HD and they had a 20 C3 LED string running on 4.5v.
I bought the 50 string believing it may work 'as is' on 12v.
Now, if I have this right, this 50 light string should use 9amps or 108 watts at 12v. Taking the 20 string / 3600ma (1200 ma per AA x 3) x 50 lights = 9000 ma or 9 amps. 9 amps x 12 v = 108 watts.

Just a guess on the math, but I'll post up again after the trials.
olddawg (author)  olddawg5 years ago
Quick update... the strings I bought didn't even work on the house current (yes, I tried this first).... I'll be returning to HD to replace and try again tomorrow....
If your going to be running more then 70 LED's (( one standard 25 foot string )) by the time you figure out the loses on every resistor, and I haven't even looked into cable loses which at a low voltage add up pretty quick, it's more efficient to use a small inverter ((( you'll only lose a few watts on a $10 inverter ))) and since your looking at about 108 watts you should be able to power up about 25 strings with out to much work ... ((( and cutting up and soldering and waterproofing and taping Christmas lights is no fun I did it to 2 sets of 70 one year and it took about 5 hours a set, and to this day I still don't know why I went to all the work when I could of plugged them into an inverter ))) but if you do cut them up and make it a 12 volt set a drill works wonders in both unwinding the twists and redoing them ... And I did them in groups of four per resistor... oh and solder each section on and test it there's nothing worse then finding out you messed up half way through .... I don't know any thing about that .... honest they where darkness emitting diodes ...
olddawg (author)  Big Bwana5 years ago
With everything involved to run 12v, I oped to go with the inverter. The main reason was to use the timer on the lights. I've never run the inverter for any length of time, never needed to before... This will make for a great test of inverter draw I still have a project string to mess with and so far I've changed over my candle lights to LED and have them running on AA batteries (which are being re-charged with my project solar modules). At some point I will make up a set, if for no other reason, but to prove to myself it can be done. Thank you for the input! I really like this site and the folks here, always good info!
the leds can be run in series groups of 2 3 etc each with its resistor each group draws the current of 1 led - so the current is led x num of series groups and not x num of single leds same with the size of string voltage depends on the size and the resistor of the group. a string with more leds may be built of larger groups (higher voltage) or more groups of the same size each (same voltage and higher current). if you connect the second one to higher voltage you burn it
Use an inverter.
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