(Another) DIY LED Build - Linear Design

[katchupoy]

of course we will do that too... thats the easiest....

 

[billyzbear]

Do you think 12 across 5ft would equal a t5's par?

 

[TheFishMan65]

Yes, I read somewhere that 1 watt of LED is the same a 3 watt2 T5. So if true 12 LEDs (running at full power) would be 108 watts of T5. So I am pretty sure it would equal one and maybe much more.

 

[bamf25]

Yes, I read somewhere that 1 watt of LED is the same a 3 watt2 T5. So if true 12 LEDs (running at full power) would be 108 watts of T5. So I am pretty sure it would equal one and maybe much more.

SO about 6 x 3w Cree LED's will be equal to a 54w T5 bulb then?

 

[TheFishMan65]

From what I have read yes, but as some here says your mileage may vary

 

[vincent201089]

I have few questions.
Are you still using the phone line for led? Is there any problem yet?
Do you think 12 leds on a 24' square 1' aluminum bar is ok? I mean is it too hot?

 

[swenholz]

Do you think 12 leds on a 24' square 1' aluminum bar is ok? I mean is it too hot?

I have 23 on each of my 48" bars with no real heat issues. The aluminum surface temp went up a little when I increased from 650 to 775 mA, but it you can still hold your hand to in with out a problem.

 

[hllywd]

I like the strip idea. I've been thinking about changing mine since I saw the 1.1" heatsinks at rapidled. How is your heat with the tubing? Also I've thought about using RJ45 plugs as disconnects. How are your telcom jacks working? Any issues?

Tim

 

[katchupoy]

To those people who are waiting for the PAR reading....


Im still slowly moving my tank inhabitants. So here is the setup.... no pictures so please imagine...

75 gallon tank
water level is 5" off the top... (not yet full)
LED rails is just resting on top of the tank.

So this means you have maybe 15"-16" inch of water, and 4"-5" distance between LED and water surface.

BOTTOM OF TANK READING

100 (cool white only) 12 x XPG @ 1000 ma
150 (royal blue only) 12 x XRE @ 750 ma

250 (white and blue) 12B + 12W

I apologize, it did not dawned on me until this morning, to see the difference between RB XPE and XRE. I will check it again tonight with pictures this time to prove the reading.

Also, midway, I cant remember the reading. Its around 300 for the white... I will check it again and report back.


I did not expect it to be so linear... meaning white + blue = whiteandblue...

I will try to be scientific next time.

I will also try is what happen when you add the third rail.... will it add additional 150 or just a few more since it is like few inches away.

 

[katchupoy]

I like the strip idea. I've been thinking about changing mine since I saw the 1.1" heatsinks at rapidled. How is your heat with the tubing? Also I've thought about using RJ45 plugs as disconnects. How are your telcom jacks working? Any issues?

Tim

For the past few months of use, the square tubing is alright. Hovering around 100F. But if you can get yourself a channel then go for it. Im worried that my square will suffer this summer.

RJ45 should be ok. You can even probably use several rails per rj45 cable since you have plenty inside. My phone cable is ok but will not do it again because its a PITA to solder this wires. It just wont stick.

 

[katchupoy]

Also to add up with the PAR reading... there is a big 30 points +/- of reading when power heads are on against when they are standing still.

Also this will dramaticaly go down when I filled my tank up to the (bottom of) rim + mount the light 9" off the water surface.

To be honest, it does not have that high reading but im very happy for a 36 bulb setup.....

 

[2hi4u2c]

The limited time I played with the PAR meter before I sent it over to you, I had a "lineal" drop in PAR as I moved deeper into the water, and an "exponential" drop as I moved the light away from the water's surface. It is a 1W X 120 LED “cheap” China fixture over my frag tank, but I would expect this to hold true with any light source..

 

[katchupoy]

The limited time I played with the PAR meter before I sent it over to you, I had a "lineal" drop in PAR as I moved deeper into the water, and an "exponential" drop as I moved the light away from the water's surface. It is a 1W X 120 LED "œcheap" China fixture over my frag tank, but I would expect this to hold true with any light source..

What was your reading with your 120 LED?

I will try later an "air" test to have more control and measured testing.
Because of your PAR meter, I was able to determined that blue, although they look darker than white, puts out a lot of PAR, actually better than whites.

 

[TheFishMan65]

They also have less response according to the Apogee curve of 20-40%. So you need to add a multiplier factor in there as well.

 

[katchupoy]

They also have less response according to the Apogee curve of 20-40%. So you need to add a multiplier factor in there as well.

Fishman, Im lost, please explain more...

 

[TheFishMan65]

At 450 nm the sensor only counts (IIRC) 65% of the photons hitting it. So if you read 100 PAR you need to divide by .65 to get you true PAR number of about 153. No the Apogee meter uses some adjustment maybe only 70%. And then there are 2 types of sensor which vary from each other by 10%.

 

[T Diddy]

B/W===B/W===B/W===B/W===B/W===B/W


...has anyone wired blues and whites on the same rail (two different drivers) with the blue and white right next to each other?

 

[swenholz]

B/W===B/W===B/W===B/W===B/W===B/W


...has anyone wired blues and whites on the same rail (two different drivers) with the blue and white right next to each other?

Yep...Blue, White, Red, and Green on each rail, 4 total rails

 

[T Diddy]

swenholz,

I guess I was curious about placing a RB and CW together in close pairs with the pairs spaced at about 3+ inches apart. The thought is to eliminate the height needed to create a uniform coloration.

this...

BW===BW===BW===BW===BW===BW

as opposed to...

B===W===B===W===B===W===B

I'll have (2) rails with (6) pairs each of B/W with 60 degree optics. (12)RB on one driver string and (12) CW on the other. Soon after I plan on adding two more identical rails.

Thoughts?

 

[swenholz]

Ah....never mind then. Sounds like time for more experimentation.