Ren48LSD's and Frank's LED Super Strips

[rjchu]

I bought a couple Ren48LSD's in the latest group buy and have some of Frank's LED Super Strips (unpopulated) as well but have some questions for the experts before I buy parts and start construction.

1. I understand the Ren48LSD's have a 5v regulator on board. If I supply 12v to the board, will it convert to 5v for the controller electronics ONLY or do the RJ45's on the top half of the board get 5v (instead of 12v) as well? I assume if I'm passing 12v to DC2 IN that the bottom RJ45's get 12v.

2. Can someone confirm these LED's look right?

http://cgi.ebay.com/100pcs-Superflux-RGB-5mm-LED-Lamp-8Kmcd-COMMON-ANODE-/290515138824?pt=LH_DefaultDomain_0&hash=item43a40d3908

http://cgi.ebay.com/100pcs-5mm-5-Chips-White-SuperFlux-LED-100mA-55Kmcd-Hot-/250746304151?pt=LH_DefaultDomain_0&hash=item3a61a4f697

3. Again assuming 12v input, what should my resistor values be? If I get different LED's than those referenced above, do those R values change and if so, how do I recalculate?

Thanks in advance, looking forward to getting some of these going for next year!

-joni-

[budude]

I bought a couple Ren48LSD's in the latest group buy and have some of Frank's LED Super Strips (unpopulated) as well but have some questions for the experts before I buy parts and start construction.

1. I understand the Ren48LSD's have a 5v regulator on board. If I supply 12v to the board, will it convert to 5v for the controller electronics ONLY or do the RJ45's on the top half of the board get 5v (instead of 12v) as well? I assume if I'm passing 12v to DC2 IN that the bottom RJ45's get 12v.

2. Can someone confirm these LED's look right?

http://cgi.ebay.com/100pcs-Superflux-RGB-5mm-LED-Lamp-8Kmcd-COMMON-ANODE-/290515138824?pt=LH_DefaultDomain_0&hash=item43a40d3908

http://cgi.ebay.com/100pcs-5mm-5-Chips-White-SuperFlux-LED-100mA-55Kmcd-Hot-/250746304151?pt=LH_DefaultDomain_0&hash=item3a61a4f697

3. Again assuming 12v input, what should my resistor values be? If I get different LED's than those referenced above, do those R values change and if so, how do I recalculate?

Thanks in advance, looking forward to getting some of these going for next year!

-joni-

#1 - Correct - the output of the regulator is used only for the onboard logic - not the outputs. The outputs come from whatever is on DC IN 1 & 2.

#2 - The RGB look OK - you do want Common Anode for the strips with the LSD. The White ones are not correct however - you need 20mA LEDs, not 100mA.

#3 - To calculate the resistor, you need to know the forward voltage drop and the current required for the LEDs. The Red are typically 2v and Green/Blue 3v. So for Red, it would be 12V-2V or 10V if at 20mA the calculation is R = V / I or R = 10V / .02A = 500ohm - the next standard value is 510 ohm. For Blue/Green, it would be 12V-3V or 9V so R = 9V / .02A or 450 ohm - the next standard value is 470 ohm.

Now with that said - I highly recommend you breadboard out a complete color set and double check everything with real measurements before building them all out. In addition, you can't trust what orientation or color will be on for each strip with the RGB Superflux LEDs so even when you do get around to building up the strips - do a single LED first by just tacking it on the board before soldering them in solid. I know for the White LEDs they were 180 off from the silk screen.

[rjchu]

Thanks for the quick and complete reply - to be honest, I was really looking for your feedback as I know you run these but didn't want to isolate the answers in a series of PM's. ;)

For item 3 below, if I'm using 12v can I get away with the smaller 1/8 watt resistors or do I need the 1/4 watts? The holes on the strips look like they'll be pretty tight for the 1/4's.

Thanks again!

-joni-







#3 - To calculate the resistor, you need to know the forward voltage drop and the current required for the LEDs. The Red are typically 2v and Green/Blue 3v. So for Red, it would be 12V-2V or 10V if at 20mA the calculation is R = V / I or R = 10V / .02A = 500ohm - the next standard value is 510 ohm. For Blue/Green, it would be 12V-3V or 9V so R = 9V / .02A or 450 ohm - the next standard value is 470 ohm.

[budude]

Thanks for the quick and complete reply - to be honest, I was really looking for your feedback as I know you run these but didn't want to isolate the answers in a series of PM's. ;)

For item 3 below, if I'm using 12v can I get away with the smaller 1/8 watt resistors or do I need the 1/4 watts? The holes on the strips look like they'll be pretty tight for the 1/4's.

Thanks again!

-joni-

To calculate the wattage, just multiply the amperage through them by the voltage across them. The Reds will be the worst case - 10V x .02A = .2W or 200mW. A 1/4W will do but will definitely run quite warm.

[michaelc]

Joni,

I'm glad you asked here because I'm looking to do something very similar. I have 12V rainbow floods on one 48LSD that is being fed with 12V and I am building another 48LSD to run potentially 5V LED's.

I' really interested in the STRIP design as well but what I'd like to see is something with an RGB, Ambe and UV LED in a single pixel. I don't know that anyone has built such a thing yet. My goal would be permanent soffit installation.

[budude]

Joni,

I'm glad you asked here because I'm looking to do something very similar. I have 12V rainbow floods on one 48LSD that is being fed with 12V and I am building another 48LSD to run potentially 5V LED's.

I' really interested in the STRIP design as well but what I'd like to see is something with an RGB, Ambe and UV LED in a single pixel. I don't know that anyone has built such a thing yet. My goal would be permanent soffit installation.

Remember that the strips have a separate color LED position - it's meant for white but you can put any color you want. I was planning to do some UV and orange for Halloween but didn't get around to it. I'm so glad I added the white LEDs to my set of strips though. I've never been happy with RGB "white". The yellow is sort of ok but I wouldn't count on getting orange out of them.

[kychristmas]

budude,
I was playing around with the Strips and the 48LSD using the White LEDs I got in the co-ops last year. One thing I noticed with those, was that I had to rotate the LEDs to make them work. I realized the other day that I wouldn't be able to rotate the the RGBs.

What is the setup for these?

Kelly

[budude]

budude,
I was playing around with the Strips and the 48LSD using the White LEDs I got in the co-ops last year. One thing I noticed with those, was that I had to rotate the LEDs to make them work. I realized the other day that I wouldn't be able to rotate the the RGBs.

What is the setup for these?

Kelly

Yeah - I made a post (http://doityourselfchristmas.com/forums/showpost.php?p=111117&postcount=63) about that after noticing the same thing - the RGBs worked OK - except that the Blue and Green LEDs are swapped. I saw this with a separate batch I purchased earlier as well. I've noted that in the LSD Wiki.

[kychristmas]

... I've noted that in the LSD Wiki.

Hangs head in shame.... I didn't even think to look there. I'll check into it and get back to you if I still have questions.


Kelly