My Led retrofit outdoor light

[shortstack]

I retrofitted my outdoor light to leds . here are some pics

the leds in the housing.

led compared to the original w/CPF

w/ the cover

leds w/cover in action vs the CPF w/cover

i used 3 cree R2's and 3 cree p4's

 

[ponygt65]

Nice work. Looks like the CFL has a bit more light output. Were you just doing a backyard test or really wanting to go LED?

 

[shortstack]

Nice work. Looks like the CFL has a bit more light output. Were you just doing a backyard test or really wanting to go LED?

Well I live in alaska where it gets pretty cold and florescent lights don't like the cold to much. Plus this retro fit uses 1/2 the power. And it actually give off just a little less. I am gonna make a 12 or 9 led version. I noticed leds woulf/will make great security lights cause of how bright they are when looking at them. Ie. Walking up to a door and them turning on.

 

[ponygt65]

Well I live in alaska where it gets pretty cold and florescent lights don't like the cold to much. Plus this retro fit uses 1/2 the power. And it actually give off just a little less. I am gonna make a 12 or 9 led version. I noticed leds woulf/will make great security lights cause of how bright they are when looking at them. Ie. Walking up to a door and them turning on.

Gotcha. LED's would def. work better overall in your climate.

 

[Illum]

nicely done!
I'm counting the wires and it appears to be either 3s2p or 6s1p
Which way did you wire it?

I was recommended those drivers at one time...but I decided to stick to xitaniums since thats what mcgizmo uses and they are sandwiched via glue and other components into fixtures that, should it fail.. I might have to lop that side of the fixture off

the way you had it set up it looks great, easy to repair
I noticed your LEDs aren't in the straight line, did you solder the wires before epoxying? usually I'd wait until the epoxy is completely dry before soldering or sometimes the wire might "pull" a string of LEDs to one side due to material stress

 

[shortstack]

nicely done!
I'm counting the wires and it appears to be either 3s2p or 6s1p
Which way did you wire it?

I was recommended those drivers at one time...but I decided to stick to xitaniums since thats what mcgizmo uses and they are sandwiched via glue and other components into fixtures that, should it fail.. I might have to lop that side of the fixture off

the way you had it set up it looks great, easy to repair
I noticed your LEDs aren't in the straight line, did you solder the wires before epoxying? usually I'd wait until the epoxy is completely dry before soldering or sometimes the wire might "pull" a string of LEDs to one side due to material stress

i have it wired 3s2p, since its a 700mA driver i wanted it to give 350mA for better efficiency. the other one im gonna make im gonna use the xitanium driver. for the price ($11) that i can connect 6 leds (350mA) its a great price.


I did epoxy the 1st so when i soldered them they wont move, i used thermal compound then some epoxy on the edges so it hold the leds down.
i ran thise for an hr strait and i can touch it and i didn't even feel any warmth

 

[Illum]

i have it wired 3s2p, since its a 700mA driver i wanted it to give 350mA for better efficiency. the other one im gonna make im gonna use the xitanium driver. for the price ($11) that i can connect 6 leds (350mA) its a great price.

While at times wiring in 3s2p may cause a hazard, in your case it will work out very well, the hazard is this: Should one string of LEDs fail the other string will receive 50% more current. If you were using a 1000ma driver and one string fails the other will be severely overdriven and eventually cooked. In your case however, even if one string fails, the current through the other string is still below the design limit.:thumbsup:

 

[shortstack]

that is some good info, didn't even think about "if" one side went out. with the heatsink i have i think that even 700mA would be fine. thanks for the info

 

[Illum]

that is some good info, didn't even think about "if" one side went out. with the heatsink i have i think that even 700mA would be fine. thanks for the info

heres some more info on that if you have the time to read up on current dividers
"Current Mirror" using BD139 NPN Transistors http://www.ledsmagazine.com/features/6/2/2

While its not a big deal in your case, I'm under the impression that for this guy he's going to need the info

I made a series of research on this ever since I first wanted to make "LED" xmas tree lights before there was a concept of it
My first approach was to modify a DC LM317 circuit thats set to current regulation and splitting up the sense resistor to multiple resistors, one for each string of LEDs, so that if one string burns up and shorts out, the sense resistance value changes and the regulator automatically cuts back on output, which ultimately prevents the other sets from cooking.
[Heres the theory of operation and wiring schematic for that]

Now whenever I work on using LEDs with line current, I prefer to have single strings only, if I need more LEDs I'll just add another driver :nana:

 

[SafetyBob]

Shortstack, if that was your first "mod", then congratulations.

Now, look at the Led Magazine's article. It is very insightful as to how to design a "really" good setup. Sometime in the future, you may be so bold as to need such electronic wizardness.

For now, Illum and I are absolutely on firm on our belief that we use ONLY single strings of LEDs with a single driver.....Xitanium is our current favorite....small, simple, realiable (in any weather), and moderately priced.

Go ahead and ask Illum if you like but I believe I speak for both of us as far as this: Have a ever had a failure of any LED connected to a Xitanium? Nope.......Malfunction....nope......Problem of any kind.....nope.

So, let's say you aren't satisfied with the amout of light coming out of your little fixture......I would slap 6 leds on there in addition to the six already there, one more driver.....6 R2's together and 6 P4's together and I think you will have one beautiful, powerful, amazingly bright (and perfect for that POW in the face you may be trying to get) light.

But the bottom line is you have one nice little light there!! Now, let's figure out how to make it even better.....and cooler!!!!

Bob E.

 

[shortstack]

well not quite my 1st mod, i did a under/over cabinet light. http://www.candlepowerforums.com/vb/showthread.php?t=220488


i have 2 Xitanium driver a 12W 350mA and a 17w 700mA. this one i just did was kinda a test but i am still using it, as i said before i am going to make one, probably w/ the 17W, and cut the mA in half. although i will probably use more p4's then r2's just cause of price, that and i already ordered them. i figured i would give these drivers a try and see how they do.

i just wonder if there will be enough headsink for 12 leds, although i could always double up the aluminuim bar on top of the other. thanks for the info

 

[Illum]

For now, Illum and I are absolutely on firm on our belief that we use ONLY single strings of LEDs with a single driver.....Xitanium is our current favorite....small, simple, realiable (in any weather), and moderately priced.

Go ahead and ask Illum if you like but I believe I speak for both of us as far as this: Have a ever had a failure of any LED connected to a Xitanium? Nope.......Malfunction....nope......Problem of any kind.....nope.

well, I'm glad to hear about our little alliance on this matter
Yeah, the Xitanium is nice. Other than the reliability it also takes the form of a ballast, which I might be able to take advatage of mounting holes if I ever decide to mod a florscent fixture with LED

shortstack, where do you buy your LEDs?
LEDsupply sells Q4s for $7.50, I bought neutral and warm whites from there
results in the lasts posts of this thread

While in most cases the aluminum bar can suffice as the heatsinking medium, I've been wondering the same about square extrusions, being that it has 4 sides

 

[shortstack]

i get them at DX cause thats the cheap i can get them. although the color temp isn't the best it doesn't bother me. i'm kinda cheap

 

[Illum]

well, with a diffuser for this particular project your not going to be able to tell the difference

 

[SafetyBob]

Illum, you didn't get my phone call? Hate these stupid cell phone.....and it was late at night, lots of chocolate, sugar high, what can I say?

Now I would say LEDSupply is a good place to get stuff and with that cloudy plastic lense over the housing, you would need a good number of LEDs in order to get a really stunningly bright light. But thats what cheap LEDs are for (and why I use alot of Seoul P4's), but give serious thought to those Q4's that Illum is talking about at LED Supply.

Bob E.

 

[shortstack]

aren't the cree r2's better, then the q4? plus i can get the r2s for $6 and some change, where as the q4's are 7.50. so their neutral whites and warm white are q4's? (ledsupply.com)

 

[Illum]

the terms N2, P3, P4, Q2, Q3, Q4, Q5, R2 are all bins for "white" succeeding one another in terms of higher output per 350ma...or at least thats what they have been utilized under. As of yet I still havent found a "Neutral white" LED flashlight before

As far as I know they don't apply for the warm and neutral whites, in fact I am as of yet unable to figure out their exact name, other than the generic "CREE XR-E"

In terms of color rendition
"White" has lower CRI [or color rendition index] than "Neutral white" which CRI = 75
"Neutral white" has lower CRI than warm white [80] but aboout 10 lumens brighter

the highest CRI LED is the "nichia 083" available from McGizmo at some price

I judge the color rendition of "white" or the Q4s I have as about 70, but they sure are bright at 350ma

 

[blasterman]

Watch out for Neutral White Crees from LEDsupply. Been losing a lot of them, although they have been patient about replacing them.

R2's are bright as hell, but I've had trouble finding them in any bin tint other than cool (purplish) white. Been mixing my R2s with warm whites to offset the coolness.

Subjectively I find neutral and cool white Crees, particularly the R2s, much brighter than warm whites. Obviously the lumen spec says so, but it seems much more pronounced to the naked eye.

 

[Illum]

Watch out for Neutral White Crees from LEDsupply. Been losing a lot of them, although they have been patient about replacing them.

Losing as in burning out?

gee...I have 14 Neutral Whites from LEDSupply burning away in the house, if you think theres something I should know PLEASE tell me :thanks:

 

[blasterman]

DOA and burning out after a few minutes. Using a 350mA regulated source, so that's not the problem .

They said I'm the only one having problems, so if anybody else reports a problem, then I know it's not just a fluke.