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Randy

A question about LOR and powering LEDs

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Randy, I think that the reason why you are able to solve the problem by connecting more than one string together is because they are full-wave rectified so there is a load on each 1/2 of the AC cycle. Frankly, I am surprised that just one string would have trouble.

With half-wave rectified strings, I'd be surprised if any amount of series connected strings will solve a flickering problem.

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The lights I have ARE full wave, that is why I am confused about this problem. If it worked for Randy, maybe it will work for me. I will try it here soon and let you know.

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I just built 3 of these and the channels I placed them on seem to be more under control. Fade still not as smooth as I would like it but at least the sporadic flicker has been reduced. 2 set of 70 with the resistor load sporadic flicker gone. 1 set of 70 flicker reduced.

Now to make up another 40 or so of these. :P

Just a quick question... The Clamshell used in the example. How would I go about making it water proof? Fill it with clear silicon?

Thank you for the tip! :]

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Dennis Warren wrote:

I just built 3 of these and the channels I placed them on seem to be more under control. Fade still not as smooth as I would like it but at least the sporadic flicker has been reduced. 2 set of 70 with the resistor load sporadic flicker gone.

Dennis, if the fading is not smooth, it is likely because LEDS are not as linear as incandescant bulbs. Example, some LED strings may appear fully bright at just 70% voltage and may shut off abruptly at 10%.

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Still a little confused about the "clamshell"

Does anyone have a picture of one or a website showing one.

I looked at Randy's pictures but I did not see the female end.

Maybe I am missing something. I would like to try building one but I

am not sure what to look for at the electrical dept.

Thanks

harbs

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Harbs wrote:

Still a little confused about the "clamshell". Does anyone have a picture of one or a website showing one. I looked at Randy's pictures but I did not see the female end. Maybe I am missing something. I would like to try building one but I am not sure what to look for at the electrical dept. Thanks harbs

Hello Harbs, if you are the same Harbs who is a member of my site, then you will find photos on there. Send me pm here or there and I will help explain.

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Hi Harbs,

In my original post at the top of page 1 on this thread, I included a photo of the Target box and my extender cord with the C7 bulb in the middle. On my cord, the male plug is at the top, and the female receptacle is at the bottom, with the C7 bulm in the middle....Can you see the female end in the photo?

Thanks, Randy

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Sorry for the confusion. I did see your pictures earlier this evening but in some of the discussions

I thought someone said the clamshell had to be installed between the controller and the LED string.

Your web site says you can use if at the end.

Thus you can plug it into the female plug at the end of the string.

I was trying to figure out how to use the male clamshell between the contoller and the LED string.

Thanks for your help and sharing your knowledge.

Harbs

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Thanks for your reply.

Yes, I can see the female and male plug in your photo.

Thanks for your help.

Harbs

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Jim, Harbs, and others. Let me clarify something where I may have misled you.

On most LED strings you can plug the "snubber" into the end of the LED string. Thus for the ones that I make where there is a clamshell with no female socket, they can plug into the end. This is because most LED strings will carry both legs of the AC line to the end of the string to supply for the next string.

However in two occasions, I have seen LED strings that did not carry the AC legs to the end without passing through LEDs first.... and thus the snubber (or C7 light) won't work. For any of these techniques to work, they must be connected across the line so that the controller sees the load during both reversals of the AC line. Fortunately, all of the old LEDs that I have are ok with the snubber connected at the end of the line. So bottom line is that if you plug in your snubber at the end of the LED string and it does not solve the problem, the you need to try it up front.

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Something to remember when buying clamshells to place at the end of the LED strings. The LED string ends are non polorized therefore the female and male end do not have a larger prong. So if your going to buy clamshells for the snubber make sure you get the type that are non polorize (both male spades same size)!!

Next, do they exist? Time to start look'n.. *grins

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Dennis Warren wrote:

Something to remember when buying clamshells to place at the end of the LED strings. The LED string ends are non polorized therefore the female and male end do not have a larger prong. So if your going to buy clamshells for the snubber make sure you get the type that are non polorize (both male spades same size)!!

Next, do they exist? Time to start look'n.. *grins

Great point Dennis. My strings do happen to be polarized, so I am not having that trouble, but I see that some newly purchased LED strings don't have the wide ground.

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Found something else of interest. I remembered that long extension cords also create a load in itself. Most of my testing has been with 8ft lengths of SP2 wire. After making a few Dual Channel 25ft Extensions I Pluged them in on my test wall...

Yes I have a test wall in my home office. *Grins...

And No Flicker. With 2 70ct LED strands. So you may not need the snubber for runs over 25ft (roughly). At least it doesn't look that way for me. Just the short ones.

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Richard Hamilton wrote:

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.



i went to radioshack and got 33 ohm, 1/2 watt resistors. to try with my LEDs, and when i went to wire them to a plug, then plug the resistor in the well outlet, one of them blow, i then wire 3 of them in series they caught fire and burn out, what could i be doing wrong

james

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I believe they're supposed to be 33,000 ohms or 33Kohms, sometimes referred to as 33K.

Since Current (I) = Voltage (E) divided by Resistance ®, using a 33Kohm resistor would give you:

I = 120 / 33,000 = 0.0036 amps

Power (P) = I x E = 0.0036 x 120 = 0.44 watts (below the 1/2 watt rating of the resistor).

If you really used a 30ohm resistor, then I = 3.6 amps, and P = 432 watts (way way too high, which may explain what happened)....

Does that make sense?

Thanks, Randy

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thanks, i was not even thinking when i went in , a 33k would = a c7 light. well give and take some

does anyone know how many watts a channel needs to work correctly, just wondering

james

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cattlefarmboy wrote:

thanks, i was not even thinking when i went in , a 33k would = a c7 light. well give and take some

does anyone know how many watts a channel needs to work correctly, just wondering

james

Well, a C7 incandescant light is going to be approximately 7 Watts. Some are 5 watts. However the 33KOhm resister will consume just 1/2 watt and that is all that is needed on a channel to appear as a proper load.

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Richard, I went to your link and I see all the text and everything....except the hi-res pictures. It could be my work site is blocking them. Are they there? Thx!

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I think you have to be a registered user and log in to his site to see the photos....

Randy

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WayneKremer wrote:

Richard, I went to your link and I see all the text and everything....except the hi-res pictures. It could be my work site is blocking them. Are they there? Thx!

Wayne, thanks for the note. You should be able to see the photos but apparently you can't. That part of the message board used to be protected, but last month I allowed guest access to those messages and postings so that LOR people could simply go there and see what they want. I need to look and see what is going on by hitting to the site as a guest on a test computer.

Sorry for your inablility to see the photos for whatever reason. As far as I now, the only area of the board that is protected are things like LOR sequence locations and other areas where there are files. The only reason to not show those areas (unless guests register as a member) is to prevent search spiders from locating files.

I will come back and post when I figure it out.

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Hi Guys,

Im a newbie to this so please go easy on me big_grin.gif

my 2009 display will be my first ALL LED display and computerizied too (LOR)

Im planning early, I know.

Im in the UK so I get to play with 240V

My question is... Has anyone driven a standard transformer from a LOR controller channel before.

I will I need some sort of suppressant over the triac (because of the transformer)

how do you think they would handle fading, shimmer and so on...?

Ive been studying your posts and i`ve decided to go full wave.

I am making most of the LED strings myself! (about 30.000 led's which is why the planning starts now)

Here in the UK Christmas lights are VERY expensive!

Im making the LED strings to run with 24V (I think its safer, and more practical)

Ive done Electronics at college so I could keep up with most of your techno talk... but it was 8 years ago so im now gonna find my books and freshen up!



Any help would be greatly appreachiated!!

oh, one last thing... Dummy loads (or Snubbers) 33K ohm for 110V (120Vrms)

Am I right in thinking 66K ohm for 240V???



Merry Christmas to all.

Trev.

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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.
I wonder if you and Richard have the same load besides these 33K 1/2W resistors. Richard was is the smallest load you have along with these resistors. Same for you stachows?

I have yet to work with a LOR controller but I am here learning all of the ins and outs of these controllers. But I do maintain Allen Bradley PLC-5 controllers with Triac out puts. I have installed IR lamps to communicate to remote devices if they are clear to proceed. And I had to install load resistors to get the output to properly turn on and off. There was a minimum current draw of like 30mA. Anything less and the triac would not work properly. I do not at this time know what the minimum current draw is for the Triacs that LOR uses.

Dan can you give us some info about the minimum value. Do you use the same Triacs in all controllers?

Thanks

Max

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There seem to be two separate solutions here. The first is to use an additional load of a 33kohm resistor (120v) or 66kohm resistor (240v) across the controller output, to ensure that the triacs always have a load. In most cases, this will ensure that the triacs turn fully off. The second point is that of using a "snubber" across the triac (from supply to output), to ensure that the triac fires correctly with small loads (typically those using LED strings). The recommendation for this is a 100 ohm resistor in series with a 100nF high voltage capacitor.

In addition, there are changes when using the controllers on 240v, such as the UK. There is a link on the board for its own dc power supply that sets either 120v or 240v, but the "kit version" of the CTB16K includes two different values of resistor that are used in series with the triac "gate" connection. The values supplied are 220 ohm for use with a 120v supply, and 330 ohm for use ith a 240v supply.

Your other point, there is no reason why a transformer would not work on the output side of the controller, as long as it is a true "wound" transformer, rather than the electronic "switched mode" type (which would only work correctly with on & off commands only). Some of the australian users (who also have 240v) are using wound transformers.

Regards,

Alan.

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