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I'm looking for circuit diagramS for ~50 LED strip with lights running* repeatedly from the bottom to the top of the Christmas tree. I found simple solutions with only 13-15 LEDs, but this is, obviously, not enough for a big Christmas tree.

The circuit must be DC driven.

Thanks.

*By "running lights" I mean this: https://www.youtube.com/watch?v=9CCWvKmVIug

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People are down vote happy on here. Maybe if you add some more information on your application and maybe even link to the smaller scale examples you referenced you will get some useful answers. Best of luck! –  Brandon Bailey Nov 30 '12 at 21:35
    
Physics to make a better question ,pls supply configuration of wiring amd colour LEDs. Is it AC driven or DC driven low voltage? –  Tony Stewart Nov 30 '12 at 22:06
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I dislike the immediate downvotes. If the person is given an opportunity to improve the question and doesn't, then do it. Otherwise, you're impacting the users negatively without giving them a chance. Instead of commenting and giving him a chance, you immediately downvoted him. Did you expect him to give you a present for this? He reacted exactly as most people would, defensively. I know the questions might sometimes not be good, but if we can help people give more informations, the questions will become better and he might become a good user. –  Gustavo Litovsky Nov 30 '12 at 22:34
    
@Richman & gl3829 Agreed. And I meant no disrespect saying people are down vote happy. I just wanted to encourage the guy to add more info and maybe get some help and maybe we can all learn something. If the question needs criticizing make it constructive! And be happy there are resources like this –  Brandon Bailey Dec 1 '12 at 0:12
    
@gl3829 the site is designed so all actions can be undone, if there is a problem with a question you can downvote it, if they then edit and improve, you can change upvote. Expecting users to tag each question they read and come back a day later to determine if you are still downvote worthy is not reasonable. A number of the vote to closes downvote on their own, it has nothing to do with the user actually downvoting. We have a number of good users who has a first question met with downvotes, it is part of learning the site, it should not run you off, nor should you feel entitled to ask anything –  Kortuk Dec 2 '12 at 4:36
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2 Answers 2

up vote 4 down vote accepted

You may want to try searching for "LED chaser".

From a few minutes of searching, this site has an example of 3 cascaded 4017s. You should have no problems extending it to 50+ LEDs per your requirements:

enter image description here

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Thank you, DeanB! –  Physicsworks Nov 30 '12 at 23:20
    
No problem! Please consider editing your question to make it more searchable for the next holiday illumination enthusiast. –  HikeOnPast Nov 30 '12 at 23:26
    
it's silly, but I haven't figured out that these running LED lights are actually called "LED chaser". Language barrier, so to speak =( ... –  Physicsworks Nov 30 '12 at 23:37
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Maybe go for this effect or this which is great and inexpensive

I have a 150 String driven from AC with 20mA avearge on each polarity protected by diodes and series currrent limiting ressitor.

I also have a 250 LED string with 24V 10W supply which feeds series parallel strings with small current limiting resistor so the Vf of the string adding up to 22V or so and 2V drop on 100 ohm gives 20mA.

I also added 12V reels of LEDs to my antenna which use a similar series resistor for each string running off a PC PSU in the basement enter image description here enter image description here enter image description here enter image description here enter image description here

I have some running of 19V DC laptop charger at ~300mA using white with 6 LEDs in each string.

Which do you prefer?

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Thanks. Do they actually RUN? What I meant by "running lights" in my question is this: youtube.com/watch?v=9CCWvKmVIug –  Physicsworks Nov 30 '12 at 22:49
    
not these but I have other blue Xmas lights with a builtin controller that permits a dozen or more sequences in groups of 3. from smooth to alternate flashing and musical variations .. So which of these do you prefer? –  Tony Stewart Nov 30 '12 at 23:19
    
The last one is what I'm interested in. –  Physicsworks Nov 30 '12 at 23:43
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