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Building an led Mega tree


Madhatter
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I'm planning on building a mega tree. I've got a few questions as I've not worked with led's before.

I've bought 5 sets of 400 Blue LEDs with an 8 function two channel sequencer. Each channel is split in to 25 16 led 2 channel sections, ech channel has 8 LEDs is series. Each set has a 24 volt 20va transformer. Each set is 31.5m 103ft overall, and 12m 39ft transformer to first bulb so should be 19.5 metres of lights or 64 feet of lights

Are these useable? I was going to cut the controller off, and cut the sets to match the height of the tree. Or find a height that matched the sections and hang the tree to that.

Whats the difference between Half wave and full wave, and does that mean I have to replace something when I remove the flip flop sequencer. ?

Have I got it all wrong ?

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Hi Madhatter

Correct me if I am wrong, but I think you are from UK. I presume your lights controllers are similar to those in Australia. Most of ours have 240->24V transformers. The controllers for LEDs almost always incorporate a full wave rectifier which usually has no filtering. The LEDs then light only at the peaks of the rectified waveform. You can see this by waving the lighted bulbs back and forth and you will see a dashed line of light rather than a continuous light streak.

Because the controller incorporates the rectifier, you need to disable the controller rather than cut it out. There have been a range of discussions on removing / disabling low voltage controllers on the Aussie LOR Users Group eg http://groups.google.com/group/Aussie-LOR-Users/browse_thread/thread/99140761d63ac98e/6a53f51283dd85b7#6a53f51283dd85b7

If the UK controllers are similar, you can open the controller, short the control transistors (triacs or whatever) by joining the supply to the outputs, and then use the string as a steady on string.

Hope this helps

Regards Geoff

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Thanks for you replies, They are fed off a 230v to 24v ac transformer , that feeds a push button controller that has two channels and a common. each 8 led's has a reisistor in line.
I need to split each set up ideally as each set is too long, I don't want a 9 metre Mega tree and I'll not have enough sets, I'll be three short even if I use 8 channels rather than 10. 5 channels would look to jerky wouldn't it so I can't double up and repeat at the opposite with the same channel. I should have bought smaller strings and more of them but they're so expensive here. £40 a set they were.

Also how do they connect to lor, do I connect the transformer to lor or is there a way of switching on the low voltage side

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If you have a LOR DC board, then you can easily split the strings into any lengths which are multiples of the 16 bulb sections. (Cutting at the 3 wire points in the string, but ensuring that you identify the common return wire at each cut.) The other important consideration is the DC voltage supply to the board - with 8 blue LED bulbs in series + a resistor you will probably require a DC supply voltage of 26-30V.

Some testing should be done to measure the voltage you need to produce currents in the string for a maximum of 10-20mA through each LED. For this testing, I use a 36V steady DC supply and a series of resistors which I connect in series with the LED string under test. Starting with a larger than necessary resistor, I measure the voltage across the resistor and the string. From the V=I.R formula, I calculate the current in the string and then knowing the number of circuits in parallel in the string, the current/circuit (ie /LED). By progressively reducing the size of the series resistor, you can measure (& plot) the LED current vs string voltage and also note thye changes in string brightness to achieve your desired result.

Where you are using LED strings with different voltages on a LOR DC board, the strings can be taylored to run with a specific supply voltage by adding appropriate resistors to each string - calculated using the results from above.

If you are not using a DC LOR board, then you will still need to supply each cut string with an AC-> DC voltage calculated as above, but with individual DC power supplies for each string - note rectifiers with filters will not respond quickly to changes in LOR outputs.

Note also that in Australia, the controller outputs are common is +ve and each of the controller outputs is -ve.

Hope this helps. Regards Geoff

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Sorry, I have no idea what you mean. Where does this 36 volts come from. The strings are 24v ac as are all uk low voltage Christmas Lights. I have no dc transformers and won't be able to get any.
Basically it sounds like Lor isn't compatible with LED's or any low voltage lights at all.

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LOR works well with low voltage transformer coupled lights in most instances. I have been using them for 4 years with minimal problems. There are however some limitations:-

For strings with controllers (LED or mini) the controllers should be disabled or removed as the controllers and LOR often interact. For incandescents, it is easiest to cut out the controllers and run directly from the transformers. For LEDs however, the rectifier required for the LEDs is in the controller and the controller is best disabled as indicated previously when the light set is used with an AC LOR controller.

Because of the limitations in AC LOR controllers for LEDs, LOR released the DC board specifically designed for use with LEDs. The board is powered directly with a DC supply which can be between 12 and 60V and the LED strings are powered directiy from this supply also. NO other transformers or rectifiers are required. I'm using power supplies from http://cgi.ebay.com.au/350W-24V-14-5A-Switching-Power-Supply_W0QQitemZ190268456976QQcmdZViewItemQQptZAU_Security_Equipment?hash=item190268456976&_trksid=p3286.c0.m14&_trkparms=66%3A2%7C65%3A1%7C39%3A1%7C240%3A1318 which are available in various voltages.

This will be my first year using DC LOR boards and DC power supplies, but all indications are that these will give better control of the LEDs than operating with low voltage transformers. Because this approach differs from simply plugging in transformers and strings, it does require more understanding of the operation and construction of LED strings. This year I'm using 6 DC LOR boards for LED strings and am looking forward to a good show. They would also be ideal for what you want to do with your mega-tree.

Regards Geoff

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They either do work or they don't, first you say they don't now they do. If a rectifier circuit affects operation by lor and makes it slow to switch then it's not compatible with LEDs is it, it means it doesn't work as its meant to.

If I need a separate dc board then that again is no good because I only wanted the megatree this year and what am i supposed to do with the spare channels , it means buying a board just for the megatree, I can only afford two boards. I've got more than 16 normal channels, and less than 16 led channels. Plus I'd have to buy a ac dc transformer which I havent got, I've bought ac transformer.
Not happy cos I was led to believe it could run LEDs by removing the controler.

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  • 2 weeks later...

Still no further forward, first LOR does work on LED's then it doesn't then it needs something called snubbers what ever they are. It will work however if I buy dedictaed boards, and new transformers and disable or replace the rectifier. I'll split one of the controllers open in the new year and see how it works. I'm still lost as to why i'd need 26 - 30 v on 16 LEDs when 400 LEDs are fed off a 24v power supply.

I'm building mega tree using the light strings as is for this year, about 4 3/4 metres high 1.5 metres base, lights will be about 2 metres off the ground so that will be 7 metres to the top, each string is 19.5 metres long, so that will be 5 * 4 so 20 strings, does that sound right?

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Madhatter wrote:

I've bought 5 sets of 400 Blue LEDs with an 8 function two channel sequencer.



LOR works very well with LEDs. Individual LED strings.

Since LOR is a controller, and YOU bought lights that already have a controller, the two contollers may not play well with each other.

Geoff gave you great advice on how to make the strings you bought work with LOR.

It's not LOR's fault that you bought LED strings with a built-in controller. The LEDs YOU bought were designed by the LED manufactor to USE ITS OWN built-in contoller, not for external control.

LOR works very, very well with LEDs, I'm using over 15,000 this year in the USA and I don't need snubbers either.

It is YOUR responsibily to purchase the correct products to integrate together. All LEDs strings are not the same, you need to do your research to make sure before going out buying stuff then blaming LOR when your stuff is not compatible.
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I expect lor to design a controller that is useable for what products are available, the norm. The majority of led light strings have a controller, therefore logic tels us that lor should design a controller compatible with those. Theres little point in designing a controller to control lights that are virtually unobtainable, no one would buy their controller.
What is a snubber ?

He hasn't offered any advice thats usefull to me, he's just confused me discussing voltages higher than the set is designed for and told me to bypass a controller that I've made clear won't be there, and said get an lor board that needs a transformer that I haven't got .
Does anyone on here ever offer advice to help people or do they only do so if they can fit a brag in of how many controlers or lights they have.
well done for telling me you have over 15,000 this year in the USA and I don't need snubbers either, when I've made it quite clear I don't even know what a snubber is.
I have about 6000 led's and over a million light, I have over £50000 of light, I have enough to decorate the town centre 3 times over. I decorate 1 house 21 flats 4 shops and two pubs and my stock has hardly been touched. I probably put on the largest privatley owned display in great britain. I don't see the point in saying that but it seems the thing to do.

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Madhatter,

The deal is that two members tried to help you out. You got an attitude because you did not understand what they where saying to you to HELP YOU out. Then one member tries to let you know LOR is compatible (which it is) and that the issue just might be YOU not doing enough research on what to get or what to do now.

Pointing the finger at LOR (they did not make you get the 400 LED’s with independent controllers) will not get you any ware on this site.

The right thing to do now would be to apologize for getting rude. We have all been in your shoes with these kinds of issues and our frustration got the better of us.

Worst case scenario is that you do not use the 400 blue LED lights that you got this year. You said you have over a million lights and have hardly even touched your stock. If I only had your issue!!

I do hope things get better for you.


The Dotys

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JBullard wrote:

Madhatter wrote:
I've bought 5 sets of 400 Blue LEDs with an 8 function two channel sequencer.



LOR works very well with LEDs. Individual LED strings.

Since LOR is a controller, and YOU bought lights that already have a controller, the two contollers may not play well with each other.

Geoff gave you great advice on how to make the strings you bought work with LOR.

It's not LOR's fault that you bought LED strings with a built-in controller. The LEDs YOU bought were designed by the LED manufactor to USE ITS OWN built-in contoller, not for external control.

LOR works very, very well with LEDs, I'm using over 15,000 this year in the USA and I don't need snubbers either.

It is YOUR responsibily to purchase the correct products to integrate together. All LEDs strings are not the same, you need to do your research to make sure before going out buying stuff then blaming LOR when your stuff is not compatible.




John, very well put.

mr dotyb excellent point.

Stan this is like going to the movies. sit back, eat some popcorn and watch the show.

( post deleted )


Attached files 166021=9559-hijacked.gif
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It is YOUR responsibily to purchase the correct products to integrate together. All LEDs strings are not the same, you need to do your research to make sure before going out buying stuff then blaming LOR when your stuff is not compatible.


It's not LOR's fault it doesn't work with lights available in the shops?
LOL sorry but did I miss the page where LOR sells lights in their shop page?
I understood that LOR was a light programmer designed to work with readily available lights from retail shops. Unless I'm missing something that would be strings of LED's with controllers attached, Strings of LEDs without controllers are rare in the UK, I've not seen them for three years and only then at Homebase. If LOR are going to claim that their controller works with LED's then they should give guidance as to how that can be achieved. The lights are afteral not a rarity in the UK and again they have told me that the LOR controller is compatible with the UK market. Now either thats a lie or they just can't be bothered to explain in English, that's English not American english as your LED's must be different to ours. I think it's the second option as i've still not had any replies to Emails sent from either address.

You can say I've got attitude all you like but that attitude has been caused by either non responses on here and from LOR or by people bragging about what they've done instead of explaining what I should do.

I still don't know why I'd be using a 26 - 30 volt supply on 24 volt LED's.
all I want to know is how do I cut the strings up and replace the rectifier. If I do replace the rectifier and place them on the original transformers or just one transformer, will they work on a normal board. I don't think it's a difficult question considering so many claim to have used LED's on here.
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The other important consideration is the DC voltage supply to the board - with 8 blue LED bulbs in series + a resistor you will probably require a DC supply voltage of 26-30V.
That bit, I don't get it. why does it need to be DC, I've got AC transformers. if I just short the shortted the controllers out and used the existing rectifier they'd be AC so I must be able to use an ac transsformer. And according to that the supplied transformer is no longer a high enough voltage.... WHY?
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With LED bulbs, the different colours require different voltages for operation. Typically the blue, green and white colours require about 3V, while the red, yellow, orange and olive greens are about 2-2.2V. LEDs only emit light when the voltage is in the correct polarity - ie they are DC devices, hence most designs include a rectifier somewhere in the string. Typically the rectifier is a part of the controller for Australian 24V sets, but for strings without controllers, it is usually included in the power pack which then puts out 24V DC, rather than 24V AC. Some Aussie strings have an in-line rectifier somewhere in the string before the lights. In Australia, the DC power packs (no controller) often include a filter to give a steady DC output voltage. These lights have a noticeable delay in switching off as the filtering capacitors have to discharge through the LED string.

For LED strings with controllers, the rectifier output is not filtered and the LEDs usually only light at the voltage peaks - LEDs are a very fast response device. You can see this effect by waving a steady lit LED string in front of your eyes when you will see a dot/dash broken light streak rather than a continuous steady streak of light. You should be able to use this technique to differentiate between full wave and half wave rectifiers. For full wave, the on/off dashes are similar in length, but for half wave, the off dashes would be about 2-3 times the length of the lighted dashes.

For a 24V AC supply, the voltage actually swings between about +/- 33V. (the 24V AC is an rms reading). When the voltage supply is rectified but not filtered, the output will typically swing between 0 and 33V, so for typical light strings, there is a proportion of the time when the voltage is above the nominal 24V supply and this is the component that actually lights most Aussie LED strings.

Good design of a LED string dictates that there should be a resistor in series with the bulbs. This acts as a current limiting device and should typically drop 10-15% of the voltage across the string.

Taking the details you supplied, string divided into circuits each with 8 blue LEDs + a resistor, the steady DC voltage required to light this string would be about 8*3V + about another 10-15% across the resistor, ie about 27V. This voltage is available within the controlleer but only for the voltage peaks.

Another factor which can impact on making any changes to the original lights circuit is the actual voltage output from the AC 24V transformers. I have found from measurements that transformers marked at 24V can vary from 24V to 30V or more at their full load currents. They also exhibit a 2-3 V drop in output from their no-load to full load operation.

Hope this additional explanation makes things clearer to you. It took me quite a lot of testing and trouble shooting before I gained at least a partial understanding of just how some of the Aussie strings actually worked and could be modifies.

Regards-Geoff

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Geoff Harvey wrote:

With LED bulbs, the different colours require different voltages for operation. Typically the blue, green and white colours require about 3V, while the red, yellow, orange and olive greens are about 2-2.2V. LEDs only emit light when the voltage is in the correct polarity - ie they are DC devices, hence most designs include a rectifier somewhere in the string. Typically the rectifier is a part of the controller for Australian 24V sets, but for strings without controllers, it is usually included in the power pack which then puts out 24V DC, rather than 24V AC. Some Aussie strings have an in-line rectifier somewhere in the string before the lights. In Australia, the DC power packs (no controller) often include a filter to give a steady DC output voltage. These lights have a noticeable delay in switching off as the filtering capacitors have to discharge through the LED string.

For LED strings with controllers, the rectifier output is not filtered and the LEDs usually only light at the voltage peaks - LEDs are a very fast response device. You can see this effect by waving a steady lit LED string in front of your eyes when you will see a dot/dash broken light streak rather than a continuous steady streak of light. You should be able to use this technique to differentiate between full wave and half wave rectifiers. For full wave, the on/off dashes are similar in length, but for half wave, the off dashes would be about 2-3 times the length of the lighted dashes.

For a 24V AC supply, the voltage actually swings between about +/- 33V. (the 24V AC is an rms reading). When the voltage supply is rectified but not filtered, the output will typically swing between 0 and 33V, so for typical light strings, there is a proportion of the time when the voltage is above the nominal 24V supply and this is the component that actually lights most Aussie LED strings.

Good design of a LED string dictates that there should be a resistor in series with the bulbs. This acts as a current limiting device and should typically drop 10-15% of the voltage across the string.

Taking the details you supplied, string divided into circuits each with 8 blue LEDs + a resistor, the steady DC voltage required to light this string would be about 8*3V + about another 10-15% across the resistor, ie about 27V. This voltage is available within the controlleer but only for the voltage peaks.

Another factor which can impact on making any changes to the original lights circuit is the actual voltage output from the AC 24V transformers. I have found from measurements that transformers marked at 24V can vary from 24V to 30V or more at their full load currents. They also exhibit a 2-3 V drop in output from their no-load to full load operation.

Hope this additional explanation makes things clearer to you. It took me quite a lot of testing and trouble shooting before I gained at least a partial understanding of just how some of the Aussie strings actually worked and could be modifies.

Regards-Geoff
thats 30 rms so it could reach voltages a lot higher than that?

I'm starting to understand this now with the help of other sites too.

so the voltage probably needs to be above 27 volts to light them.

is there a way i can split the strings and use the original transformer feed the controleler with the controller bit shorted then plit that into two to feed the two strings as two channels. In other words can each channel have its own power supply or are the boards fed off one common power supply to feed all channels.

also, what will happen if i get rid of an led on some icicles I've got, ones gone bad, if i short it out the rest light.
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Madhatter wrote:

thats 30 rms so it could reach voltages a lot higher than that?

I'm starting to understand this now with the help of other sites too.

so the voltage probably needs to be above 27 volts to light them.

is there a way i can split the strings and use the original transformer feed the controleler with the controller bit shorted then plit that into two to feed the two strings as two channels. In other words can each channel have its own power supply or are the boards fed off one common power supply to feed all channels.

also, what will happen if i get rid of an led on some icicles I've got, ones gone bad, if i short it out the rest light.

Because the LOR boards switch the AC supply to the transformer. you are limited in the number of controllable channels by the number of power packs & controllers you have (ie 1/string). It is possible to rewire the split strings to get more channels if you find additional power packs that are identical or compatable. You must then join the commons and use the supplies to feed the required individual channel wires.

Regarding dead leds, I believe it is best to either leave them in circuit if the rest are working OK, or replace them with a resistor to give the same voltage drop at the operating current. (I have used the resistor approach on a few strings). To size the resistor, you need about 3V @20ma for blue, green and white LEDs (ie ~150 ohm) and 2V @ 20ma for the others (ie ~100 ohm). Low wattage resistors are OK.

Regards - Geoff
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Sorry but I wouldn't have a clue how to size resistors even with the information you give, I don't know how to find the voltages the set runs on now, so I don't know how to find out if the existing transformer will work half the set, or if I buy exactly the same one voltage and wattage, will that run the other half. Maybe it's really simple and i'm trying to make it complicated.
From what you've said the high power 24v ac transformers will be no good?

think it will just be cheaper to go and exchange these lights or go and buy another 5 boxes next year and leave them the length they are just double them up, or buy shorter strings.

Would be better if LOR was just a switching unit and we fed in the supply to each channel.

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Hi Madhatter....

Paul here from Somerset, UK........

Hope you have got some things sorted now, and kicking back ready to enjoy the holidays.

I'am using LOR here. I can't really give any advise on the led controller thing, and i know its so frustrating. The lights we have available to buy here in the UK are basically crap, overpriced, and you can't do an awful lot with them.

I get all my stock from the States, they're better priced, better quality, and more versatile.

You can plug sets end to end, stack em etc......

I'am getting another LOR controller for next year, and thought i might have it set to 240v, but thought probably not, because the lights we can buy here in the UK would be a nightmare to adapt because of modifying and disabling the controller which comes with them.

Here's a news video of my display. http://uk.youtube.com/watch?v=FxsR9PdcLW4

If you ever want to chat, mail me on paul1toole@aol.com

Chat soon hopefuly

Paul

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I have actually got a couple of static sets of LEDs that my bro bought from focus at a stupidly expensive price. On the quality side They've been out in all weathers for the past few years along with the Argos and B&Q ones and I've not had a single faulty LED, only the homebase ones have any faulty on them. I'm tempted to replace it with one out of a cheap battery set, dunno if that would work.

If I could understand how to find out what transformers to use I'd that but I don't get all this voltage stuff. It's ok if you've already done it, it's easy.

I'm not sorted at all though, I've had a bad year, I've not got everything done that I wanted so in reality I'd have had no chance of setting LOR for this year to the extent that I wanted and the local council seem hell bent on blocking me. I need a scaffolding tower or cherry picker, plus certificates etc, plus pat testing, plus insurance.
Now I can't work out how to do the top of this tree so it never has got done, I tried again today, i need to divide a circle into 20 , i dunno wether to just guess or what . If i do it now it will be ready for next year, cos if i do somehow find 2500 quid it's going to take months to set up on my own.

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The problem is the US uses 120 volts AC and "our" lights regular and LEDs are setup for that, at least those purchased here. I'm not sure exactly what voltage you use in England, but it would stand to reason LEDs purchased there would work there. If you want help from anyone you're going to have to provide more information and not be so condescending or upset with people who don't rush to your aid. You're asking for someone to fix "your problem" and teach you electronics at the same time and long distance at that.

Have you tried asking a local electrician, teacher, professor for help? Goggle-ed your question(s)? Not to mention, even though we both speak "English" I find your posts hard to understand exactly what you are saying and I don't know if that is a language thing or a lack of knowledge on your part to convey your problems to us. I know there are alot of people using LOR products in Canada and Australia with different electrical systems than us and they are very happy.


The person in this reply from Australia has alot of great info in his post and also the one from England. You may want to use PC's users list to find others in England to e-mail or call and get ideas/solutions from.


Lastly, a call or e-mail to LOR may be very helpful as they are some of the sharpest and most helpful I have found in the business. Remember, this is the busiest time of the year and it may take them awhile to get back to you, but I'm sure they will, if youre patient.

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Madhatter wrote:

Now that IS a nice display paul, well done. It really is a rarity that I have the chance to say that about a uk display, they normally look like a shop display with lights thrown up anyhow.
I take it that they're all on 110v.


Thanks for the lovely comment...really do appriciate that!!

Yep they're 110v American lights

Depending on how many lights you want in your 09' display. You might want to use 110v American lights...i can help if you like, sourcing and helping you get these.

Just to give you an idea.....Sets of LED's from the States range from $8 upwards. The only real costly thing is having them shipped.I do go over a quite a few times a year, so maybe we could work together in getting you the display you really want.

Changing the voltage is really easy, enabling you to use them here in the UK.

Once you know what you want, how many lights you want etc......do some simple math....wam bam your there.

I use (Site Transformers) they're the little yellow boxes, that builders use, to use 110v power tools. They're normally rated at 3.3kw or 5kw 16 & 32amp

If you use lets say the 3.3kw 16 amp version, and work with 80% you'll have 12.8amps & 2640 watts to play with for each transformer.

Each set of US LED lights are normally 4 or 7 watts per strand and 0.04amps or standard incandesant strings 100 count normally are 44 watts & 0.33amps

So doing some math to find out how many you can run on a transformer is simple.

I'll be here whenever you want, you should have my email, but incase you haven't it's paul1toole@aol.com

But for now, i would say, go down the 110v American Lights road, you'll not look back, trust me

Email me for some more info, and if you get stuck.

Merry Christmas & A wonderful New Year 09!!!


Attached files 168196=9687-Panorama view opening night.
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