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A question about LOR and powering LEDs


Randy

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I've been doing some experimentation with my LOR controllers trying to get smoother fades with LEDs. I have some Target LED Branch Trees, and also tested some CDI LED strings of 50 that have a flash when dimming at about the 50% level.

The Target trees flash 3 times and then go out when dimming at about the 50% level...

So, remembering from a thread last year about helping out LOR channels with light loads, I built up the device shown in the attached photo (C7 lamp in series with LOR Controller channel).

Sure enough, it smoothed up all the fades, on the CDI M5 50 ct blue LEDs, and even on the Target Branch trees. Smooth as silk. So now I guess I've got to build up a few of these to use in this year's display where the flickering is noticeable....

So, a question for LOR....Is there any way that the controller firmware can be modified to get the same behavior without having to add "the Doo-hickey"? I'm willing to build a few of these, but more than a few starts to take some time....The C7 bulb adds 5 watts when I'm trying to save energy with the LEDs....It'd be nice not to have to do this....

Anyways, I wanted to let folks know about this solution, but also wanted to see what the LOR folks might have to say about it....

Thanks, Randy


Attached files 160141=9306-LED Tree 1.JPG

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Randy, that is a good solution and should work well, but if you want an even simpler and cheaper solution that does not require the distraction of a white light coming on, then take a look at my alternative....
http://magiclightshow.com/bb/index.php?topic=41.0
I have a description and hi res photos there.

Also, this is not something that can be corrected in firmware. Triacs and SCRs need a small load to operate properly. You could add resistors to the channels in the LOR unit, but I advise against that so as to not risk a warranty issue if you screw up something. Besides, the trend is moving toward full-wave rectified LEDs and similar techniques that won't cause this issue with most LED strings. Only the cheap ones usually have this problem.


Edit: Oh and I forgot to say that the solution I use will need only a 1/2 watt resistor, not a 5 watt bulb.

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Thanks for the info, Richard. I was able to log into your site and check out the photos...I'll try to build some.....

Thanks very very much......Randy

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Richard, you provided good information, but I tried your tip exactly as you did, and it did not work,

Using a c9 bulb did work fine

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stachows wrote:

Richard, you provided good information, but I tried your tip exactly as you did, and it did not work,

Using a c9 bulb did work fine



Really! That is interesting. I am using about 15 of them on different channels of different controllers without issue. Are you sure that you used the right value of resistor? CrazyLady is also using this size of resistor in her thread, but she chose to solder and glue all that stuff together with modified extension cords.
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Yup... just got back from radio shack... 33K ohm, 1/2 watt resistors...

Tried 3 of them same results... They were REALLY cheap lights though... Thought if could use them with a terminator they would look OK.

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stachows wrote:

Yup... just got back from radio shack... 33K ohm, 1/2 watt resistors...

Tried 3 of them same results... They were REALLY cheap lights though... Thought if could use them with a terminator they would look OK.

Hmmm that is puzzling. I just called my colleague in Tennessee to ask if he had any trouble with his terminators and his are also working, but without the terminators, his lights are sporatic.

I would guess that your LEDs don't matter if they are cheap since you mentioned you got them to work with a C9 bulb. That result tells me that there is still not enough load on the circuit by using a 33K Ohm resistor. I did a little experiment just now and I am able to go as high as 45K before the lights start flickering again. Of course going lower on the resistor value will help, but it can't go too low or else a 1/2 watt resistor will get too hot. 33K will use .4 watts at 120 VAC. That should be enough to fool the Triacs into thinking a constant load is on the circuit.

Yea, I expect there to be some differences between the components in various manufactured controllers, but I would not expect there to be enough difference to cause this technique to work on some controllers, but not others. Just to be sure I understand what you did... You put the resistor ACROSS the AC line (like inside of a housing) instead of putting it in series with the lights? Right? It will be interesting to hear of other people's experience and comments.
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Richard, here is what i did to test your method....
Also, i put the terminator at the end... Used to playing with SCSI terminators...

Should it be before the lights? I would test it, but my halloween show is now runnigng for the night.



Attached files 160197=9309-PICT0035.jpg

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stachows wrote:

Should it be before the lights? I would test it, but my halloween show is now runnigng for the night.


Bingo, that is your problem. Remember that the LEDs you are trying to fix are likely half-wave rectified. That means when the AC current flows in the direction against the diode, then no current will flow and therefore the controller will not see a load.

By knowing what you do for a living, I know I don't need to tell you this, but for other folks testing like this, DONT KILL YOURSELF. There's 120 volts across the terminals of that resister. Of course, this is why I house it in one of those clam shells.

FYI... on rare occasions, I come across the clam shells that also have a female socket on the end. Those are best because they let you plug your lights into the clam shell without needing a 3-way adapter. This is something that the Randy thought about when making his light terminator. Bottom line is to put that resistor across the AC connection (in front of the LED string). Several kind of adapters are available for doing that. You could also use the one you have, cut the terminals short and epoxy cover the resister.
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That should do it... I will test, and then I will put the resistors in a safe enclosure...



Thanks for your help...!

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stachows wrote:

That should do it... I will test, and then I will put the resistors in a safe enclosure...

Thanks for your help...!

Let me toss in one last step. Even though I am very confident making things like this, and the clam shells are practically foolproof to make, I still use a voltmeter to test across the plug to make sure there is no short circuit before I use it. I would not want to be embarrassed to tell Dan that I blew out a controller channel !!!
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Richard, I completely understand....

If I blow out a controller I would just call Dan and blame you anyways!!!:shock:

Just kidding! Thanks again!

Scott

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What do you mean by plugging it in before the lights? It looks like if I plug the thing you made into the channel then there is no way for the light string to plug into. What am I missing?

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I think you can accomplish plugging in the device ahead of the lights because the end of the LED light string cord has a male plug and a female socket on the back side of the plug.

Controller --> Extension Cord --> LED Light plug into female end of extension cord & load device in female socket of LEDs --> Lights --> end of string

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JimCanfield wrote:

What do you mean by plugging it in before the lights? It looks like if I plug the thing you made into the channel then there is no way for the light string to plug into. What am I missing?

Hi Jim, that is what I mean in my earlier post. If you use a clam shell with a female connector on the other side, then you can plug the lights into that. Otherwise you have to use a 3-way female plug and no sense in spending an extra dollar for that too.
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Richard and all, just thought I would let you know that I retested my lights with the terminator BEFORE the lights, and the results were MUCH better. One string still had a VERY slight flicker around 50%, and the other was just fine.

Time to start making water proof terminators...

Thank you all for your input!!!

Scott.

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I see that now, sorry about that. I think I will look else where to fix my problem because I am not sure what is being said about the clam shell, and I know I am not good enough to wire something to the extention cord. The first idea seemed simple enough. Would the idea of plugging the plug protector into the back of the forst light string work as Randy explained?

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JimCanfield wrote:

Would the idea of plugging the plug protector into the back of the forst light string work as Randy explained?

Jim, if I understand your question correctly, the answer is no. Regardless of the technique you use, the device must be connected between the controller and the first light string to get it to work properly.
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JimCanfield wrote:

would it be possible to expound on the clam idea? If it is not to awful hard I may try it.


Jim, it is a LOT easier than you think. The clamshell already has two screw terminals in it. All that is needed is to attach a 33K Ohm 1/2 watt resistor to the terminals and close it up. The clamshell are available at Home Depot for about 80 cents and an pack of 5 resistors are Radio Shack are $1. I built 25 of them in about an hour.

The photos of the clamshell that you saw on my web site are not exactly the ones I use. I have the version that also has a female connection at one end and a male connection at the other end. This is to allow you to plug it into the LOR circuit and then plug a string of lights into the clamshell. These types of clamshells are harder to find. I'll see if I can locate some.

You picked up on the problem with using the type of clamshell that does not have a female socket on it. In that case you would also need a 3-way adapter and that just increases the cost by another dollar. The photo I posted was just to show the technique.
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