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CDI 2009 LED M5 Samples - PART 2


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If I understand correctly, the 50 ct strings perform somewhat better because they are less noisy than the 100ct, and they don't "fade" off like the 100ct (it seems that large cap in the 100ct circuit is keeping the LEDs lit for a short while).

Why not just manufacture the 100ct strings to be essentially two 50ct strings? I can see the noise, color and afterglow of the 100ct being fairly sizeable issues. I know scale of economy says that 100 led's running off of one circuit would be cheaper than 100 led's running from two circuits, but it sounds like the 50ct circuits perform much better.

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If I understand correctly, the 50 ct strings perform somewhat better because they are less noisy than the 100ct, and they don't "fade" off like the 100ct (it seems that large cap in the 100ct circuit is keeping the LEDs lit for a short while).

Why not just manufacture the 100ct strings to be essentially two 50ct strings? I can see the noise, color and afterglow of the 100ct being fairly sizeable issues. I know scale of economy says that 100 led's running off of one circuit would be cheaper than 100 led's running from two circuits, but it sounds like the 50ct circuits perform much better.

I don't think that would fly because there would need to be some sort of lump in the middle of the string to house the extra components.

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I don't think that would fly because there would need to be some sort of lump in the middle of the string to house the extra components.

And why is that a problem? This is the norm for long strings until these isn't it. If I had my choice I would far perfer to have a bump in the middle and have strings that both dim well and are reliable plus remove the electrical noise. You know a good old rectifier with dropping resistor. Split the string into two to get the higher counts.

RJ

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Hardware - Renard 16 channel board

Software - Vixen

Lights - All 8 strings sent by Paul plus a red incandescent set as a control of sorts.

Testing

[*]Ramp up to full and down to to zero.

[*]% of intensity at first visible light.

[*]Cool Wht 50 - 15% with flicker, smooth at 20% but brighter

[*]Cool Wht 100 - 20% barely visible, big jump at 35%

[*]Blue 50 - 15% with flicker, smooth at 20% but brighter

[*]Blue 100- 25% barely visible, big jump at 35%

[*]Green 50 - 10% barely visible, 15% flicker, 20% smooth, brighter

[*]Green 100

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The LED bulbs appear to be sealed and not replaceable.

I have posted a video of fading these strings at http://vimeo.com/2460432 (Strings in order from left to right: Cool White LED control, Red incandescent control, Green 100, Green 50, White 100, White 50, Red 100, Red 50, Blue 100, Blue 50)

YAY! I like sealed non-replaceable bulbs. No more "brush against a bush the wrong way and have to troubleshoot" problems.

The video hasn't been converted yet, apparently because there are a ton of videos being uploaded right now, but as soon as it does, I will go check it out.

Thanks to everyone who is testing the samples to evaluate and to help to get us yet another product that we can be proud of. And a special thanks to Paul for allowing you all to do so. There aren't many companies out there who would let regular users test the product and allow everyone else to comment on it in a public forum like this, and that is very admirable of both him and the manufacturer for allowing all of this discussion to take place.

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Here's a test I'd LOVE to see performed on these strings....

1. Connect 64 strands of 50 count bulbs to a LOR controller, 4 in series per channel.

2. Using the hardware utility, simply turn on channel 8 to 50% intensity. All other channels off.

3. Make sure you're in a dark room during this test.

4. Become horribly depressed as you notice all 15 other channels flashing erratically due to the kickback electrical noise from channel 8.

Seriously, the new strands may fade beautifully at some point, but cross channel interference is a major, major problem in circuits that use series capacitive current limiting.

Has anybody tested this function yet?

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Here's a test I'd LOVE to see performed on these strings....

1. Connect 64 strands of 50 count bulbs to a LOR controller, 4 in series per channel.

2. Using the hardware utility, simply turn on channel 8 to 50% intensity. All other channels off.

3. Make sure you're in a dark room during this test.

4. Become horribly depressed as you notice all 15 other channels flashing erratically due to the kickback electrical noise from channel 8.

Seriously, the new strands may fade beautifully at some point, but cross channel interference is a major, major problem in circuits that use series capacitive current limiting.

Has anybody tested this function yet?

I don't think that anyone has 64 such strands, I certainly don't. I also suspect that there won't be anywhere near as much trouble with the 50-ct strings as there would be with the 100-ct items. And - just my personal opinion - I think that solving this problem (if it exists) is as much the responsibility of the controller vendors as the light vendors. It wouldn't help people who have already bought controllers, but there are things that the controller designers can do to prevent or minimize this problem.

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I don't think that anyone has 64 such strands, I certainly don't. I also suspect that there won't be anywhere near as much trouble with the 50-ct strings as there would be with the 100-ct items. And - just my personal opinion - I think that solving this problem (if it exists) is as much the responsibility of the controller vendors as the light vendors. It wouldn't help people who have already bought controllers, but there are things that the controller designers can do to prevent or minimize this problem.

I think our best bet is to find lights that will work with our controllers (like the 2007 LEDs from CDI) not change our controllers to make them compatible with LED strings that seem to have a problem working with them, because there are others that work fine.

These current LED stings seem to have been greatly improved over what we are trying to operate with right now.

I have not heard of any complaints about any the other LED vendors lights, or the 07 LEDs that CDI sold.

Its not practical to expect the controller vendors to change their controllers to try and work with one certain brand of LED lights. What if they did make a change and it now worked perfectly with these lights, but it no longer worked with the LEDs that it previously worked with? Stranger things have happened.

If some type or regulation were to come about and the new 'regulated' LEDs did not work with the controllers then that is a different story. I am sure the controller vendors would start researching that problem pretty quickly.

I am sure Paul will get this worked out for us one way or another!!

And this is just my opinion of course.:)

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I just wanted more of a string load on the channels. The 2008 string noise problem gets much worse the more strings you tie on in series and try to dim. I'd actually love to see many, many more tied together, but I was hoping somebody might get at least 64 of them to try out.

I really, really want to dim these things! The letter sent out by CDI described what the new strings would be like, but did NOT say that they would be dimmable.

I also don't think you should say a string is dimmable if it generates all kind of junk electrical noise in the process.

After buying nearly 1700 of these, and looking to add almost 2000 more next year, this has to be right!

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With the rectifiers being relocated into the plugs can the light sets still be lengthen with wire so that they will work on arches or are we just going to have to make harnesses with plugs hanging from the arches? I would also have to agree with Tony that losing the piggy back style plugs will be a major pain in the you know what.

Eddie

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With the rectifiers being relocated into the plugs can the light sets still be lengthen with wire so that they will work on arches or are we just going to have to make harnesses with plugs hanging from the arches? I would also have to agree with Tony that losing the piggy back style plugs will be a major pain in the you know what.

Eddie

Both plugs are needed, one male and one female. You cannot remove either one, although I think that you should be able to lengthen the wires between the LEDs and the plugs. The plugs are fairly big on the M5 samples that I have, about 2 inches long (excluding the prongs).

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I just wanted more of a string load on the channels. The 2008 string noise problem gets much worse the more strings you tie on in series and try to dim. I'd actually love to see many, many more tied together, but I was hoping somebody might get at least 64 of them to try out.

I really, really want to dim these things! The letter sent out by CDI described what the new strings would be like, but did NOT say that they would be dimmable.

I also don't think you should say a string is dimmable if it generates all kind of junk electrical noise in the process.

After buying nearly 1700 of these, and looking to add almost 2000 more next year, this has to be right!

What type of strings are you having problems with? Are they 50ct or 100ct?

While I haven't tested the sample strings yet (other than to apply AC power to them), I would think that there would be a lot less likelihood of 'noise' problems with 50ct strings than 100ct, since the capacitance that is being charged when the controller outputs turn on is a lot smaller with the 50ct strings. One possible thing that might help would be to add a snubber in parallel with each controller output. This would consist of an appropriately sized resistor and cap in series with each other.

The strings that people have now are all just samples. I only have one sample each of about eight different strings, and I suspect that the same is true for the other testers. In the course of events I will try placing the four 100-ct strings that I have in parallel across one of my DIY controller outputs and one each 50-ct string across other outputs, and see what happens. This is not the best possible test because each of the different color strands will potentially have their current surge at different moments in time, so it will not be as rigorous a test as if they were all the same color/type.

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Has anyone tried adding a small load, like a 60w lamp in parallel with the offending, noisy 100ct LED's? I wonder if a resistive load in parallel with the noisy strings could snub the noise? Not sure if it would work, but it'd be nice to try. We use this method were I work (traffic signal technician) when the LED traffic signals act up while "off". A 60w lamp usually solves the problem until we can address the issue and resolve it. Of course, it partially negates the LED energy savings.

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With the rectifiers being relocated into the plugs can the light sets still be lengthen with wire so that they will work on arches or are we just going to have to make harnesses with plugs hanging from the arches? I would also have to agree with Tony that losing the piggy back style plugs will be a major pain in the you know what.

Eddie

You can most certainly lengthen the 3 leads on each end. Just make sure you dont cross the AC lines (hot and Nuetral) mark one lead with a sharpie and cut it the middle of the mark so you can tell which is which.

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The 2007 leds (M6 Crystal) from CDI work awesome. I have them in my display right now being driven by a D-light AC16. Great fades, very bright, no issues.

(I want MORE OF THOSE ;)

Rub it in! LOL

Yes we all wanted the 2007 model. Mine have failed so fast I may have to shut down the show before too long as I am out of strings to replace.

I use 70 ct strings, I wondering how they will compare. I am still concerened about the amount of noise created when they are dimmed.

RJ

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I agree with you Chuck. I have 120 of these M5 100 count minis and M5 160 count nets in blue and green and my controllers go nuts from the noise in the lines. I have channels all over the yard popping on and staying until that channel is either accessed by the controller or the song ends.

I have a couple of nearly static songs that are dynamically changing each time they play.

I personally love the one clear string that comes on in my mega tree when the rest of the tree is either solid green or blue. And when the red shrubs or red lights on the house come on during Blue Christmas. I even have clear, red, green and blue all come on at the same time. Make for quite the power load on the breakers.

It's very embarrassing to have worked so hard to get things just right in a sequence only to have this crap happening every show. BTW, I have an incandescent load of at least 50 mini's on every single channel that have these led's on them as well as a 3.3K Ohm resistor soldered in series on each of the led strings. The strings are still burning out with the resistors on them too.

Everything I have is 50 count C6. The blue's are the worst offenders, by far.
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I've been making a few preliminary observations of waveforms on the second batch of sample strings. Here are a few representative waveforms for the cool-white LEDs (the green and blue have similar waveforms, red are simpler). These waveforms were generated using a DIY controller set for maximum brightness, which had the triacs coming on early in the cycle. As you can see, the waveform for the 50-ct string (the first one) looks pretty scary, although the 100-ct doesn't look too bad. Based on these waveforms I would have to reverse my expectations, with the 50-ct strings creating a lot more 'noise' than the 100-ct strings (this trend seems to continue even at lower intensity settings).

Edit - I forgot to mention - the waveform that looks like a sine wave in each picture is the AC line on the output of the isolation transformer that I'm using (vertical setting is 50V/div). The other trace on each picture is the voltage across a 1 Ohm resistor in series with the string, so it represents the current through the string (vertical setting is 50 mV/div => 50 mA/div).

Second edit - replaced 2nd photo with a better image.

post-3848-129571094749_thumb.jpg

post-3848-129571094762_thumb.jpg

Edited by pshort
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It's very embarrassing to have worked so hard to get things just right in a sequence only to have this crap happening every show. BTW, I have an incandescent load of at least 50 mini's on every single channel that have these led's on them as well as a 3.3K Ohm resistor soldered in series on each of the led strings. The strings are still burning out with the resistors on them too.

Tim,

I still plan to get out this year and see your display. Being local to you, I could have helped you rebuild those strings. Hope things get better for you from here. I'm sure your visitors still enjoy your display, but can understand the frustration.

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