Basic circuit for PLCC6-5050 RGB LEDS

AussiePhil

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Hi all

Here is the circuit i have been using to wire up the PLCC6-5050-RGB Led's sourced on the last group buy.

I have not posted this before as pin outs can vary, but it is likely more useful then not

So caveats

1. Circuit is of my setup and testing and is for 27.5 volts

2. Green - Red - Blue order can be different as can the pin numbers as well as pin 1 location.

3. Resistor values are for 27.5v

4. For 12v use three leds.

5. Were the circuit is shown going to ground would be the wiring back to the controller.

Cheers
Phil
 

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ThaiWay

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Thanks for that Phil. This confirms what smartalec and I worked out in chat.

The diagram is much appreciated!

John
 

ron

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Hey Phil.

If you have time, can you snap a picture of one of your strings in a couple of spots? I'd like to see how they connect at the Tiger 120 and how the different segments tap into the main power feed line.

Assuming I'm picturing this correctly, which I many not be. Does each segment have a run of ribbon cable back to the 120, so each segment has a longer ribbon cable from the 120 to the start of the segment? And there there is a main power feed that each segment taps into? Do all the segments cables get bundled together some how?

That's sort of the way I'm picturing it works right now, but I may be completely off. I think the pics would help.

Ron
 

AussiePhil

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Ron

you have it correct, each section runs back to the controller as you describe. I have a single thick wire providing positive voltage for each section in the string.

Photo's when i get the string out of the box.

Cheers
Phil
 

rokkett

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For a very specific project, I want to use one PLCC-6-5050 LED per channel. I was thinking about just using 12 V, as that was the minimum for the Tiger120, but I have a several 24 volt power supplies for another project lying around. The one advantage I see, is that with 24 v, the RGB LEDs each use the same 1200 Ohm resistor. But that, of ocurse, is more expensive. Any other reasons I should consider concerning the driving voltage with the Tiger120?

Thanks!
 

AussiePhil

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Rokkett

The T120 will accept voltage input as low as 6V if needed and this would be better with a single LED.

The other (better) option would be to use a 20mA constant current chip like a CL2N3-G for each channel.

Cheers
Phil
 

rokkett

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Thanks, Phil! I will check out the CL2N3-G device, but it may prove too costly for 214 channels...

Ok, so here is my new plan. Seven RGB LEDs per strand. And use 24 volts. Red will get a 560 Ohm 1/4 watt resistor and Green and Blue will use an 120 Ohm 1/8 watt resistor. Thoughts/comments?
 

AussiePhil

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A couple of comments

at 24v, seven will be fine as long as you are prepared to measure the Vf of the seven leds to get the correct resistor, for Red it's a non issue really but for blue and green it would be important.
If the batch you got had a B/G Vf of say 3.4 (high end of range) then the total for 7 would be 23.8 leaving just 0.2v to drop across a resistor... this is then poor design and will lead to issues.

If you get a batch at say 3.1V then all would be good.

The resistor values you quoted sounded about right for "normal" measured Vf's for 5050 leds

Just buy 1/2W resistors, they generally are just as cheap and will never overheat in the above use.

Cheers
Phil
 

David_AVD

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I reckon 7 green or blue LEDs in series is not enough margin for 24V use. I'd drop down to 6 personally.

As Phil said, there needs to be at least few volts dropped across the series resistor to ensure reliability and consistency.
 
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