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Discussion Starter · #1 ·
A couple months ago with help from this forum I planned out my LED light. Thread here:

http://www.plantedtank.net/forums/10-lighting/986690-5-channel-led-lights.html

A few weeks ago I finally got the parts ordered, and now am getting the build started.

I'll be using the MakersLED slim heat sink, with LEDs and LDD driver/board and power supply from Steve's LEDS.

The finalized plan is here:
http://www.plantedtank.net/forums/8797873-post11.html

I was hoping to be able to put the drivers inside the heatsink. I bought the 8 channel driver board because my I have 8 PWM channels on the controller and figured I may add three more channels later. This is where the plan starts to deviate.

I initially wanted to put the driver board inside the light fixture attached to the heatsink. This would limit the length of the wires the LDD drivers had to drive. However the 8 channel board is too large and will obstruct LEDs, so change of plans. I'll now put it in the tank stand near the power supply.

This means I needed a multi-conductor wire to get from the LDD drivers to the LEDs. I just bought 25ft of 10 conductor 22 gauge mutli-conductor wire. I went with dedicated supply and ground wires because I wasn't positive you could have two LED chains share a common ground. I figured that would mess up the drivers. This is enough for the 5 channels, if I move to 8 channels later, I'll have to find 16 conductor wire. I looked, but couldn't find anything larger than 26 gauge and I was afraid that was too small.

The MakersLED heatsink is really nice. They provide end caps and a plexiglass cover. You can use 4-40 machine screws to fix the LEDs, which I liked.

Everything from Steve's LEDs came very well packed. So far I'm very happy with what I've received.

david
 

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I'm curious what size tank is this for. I'm build a light myself, soon, for my 40b, but I'll be using vero 18's instead of individual 3w led's for my whites.
 

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This means I needed a multi-conductor wire to get from the LDD drivers to the LEDs. I just bought 25ft of 10 conductor 22 gauge mutli-conductor wire. I went with dedicated supply and ground wires because I wasn't positive you could have two LED chains share a common ground. I figured that would mess up the drivers. This is enough for the 5 channels, if I move to 8 channels later, I'll have to find 16 conductor wire. I looked, but couldn't find anything larger than 26 gauge and I was afraid that was too small.


david
24 gauge:
166-2499-998 Amphenol Spectra-Strip | Mouser

OPP'S min 1000ft........ :eek:
24ga is rated for .577A power transmission..
The Maximum Amps for Power Transmission uses the 700 circular mils per amp rule, which is very very conservative. The Maximum Amps for Chassis Wiring is also a conservative rating, but is meant for wiring in air, and not in a bundle
http://www.powerstream.com/Wire_Size.htm
 

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Discussion Starter · #4 ·
This is for a 46 Gallon bowfront tank. The light is 36" long.

david

I'm curious what size tank is this for. I'm build a light myself, soon, for my 40b, but I'll be using vero 18's instead of individual 3w led's for my whites.
Bump: Yes, I saw that and other 16 conductor wire, but I didn't nee 1000' or have $3000+ to spend on it :)

I was able to get my 10 conductor 22 gauge wire for $25 shipped.

david

24 gauge:
166-2499-998 Amphenol Spectra-Strip | Mouser

OPP'S min 1000ft........ :eek:
24ga is rated for .577A power transmission..


http://www.powerstream.com/Wire_Size.htm
 

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Discussion Starter · #5 ·
OK I was looking at the heatsink and the LDD driver. If I were to put my CC and WW LEDS on the outer most rows of the heatsink, I could fit my driver board in the light. How would I figure out if placing the LEDs closer to the edge of the heatsink would cause an issue with the edge of the heatsink creating a shadow on the tank below?

Intuitively I think it would work as the height of the LED and lens is .5 inches. This is most easily seen in the end view of the drawing I posted. I know that using trig there is a way to figure this out. Anyone know?

david
 

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OK I was looking at the heatsink and the LDD driver. If I were to put my CC and WW LEDS on the outer most rows of the heatsink, I could fit my driver board in the light. How would I figure out if placing the LEDs closer to the edge of the heatsink would cause an issue with the edge of the heatsink creating a shadow on the tank below?

Intuitively I think it would work as the height of the LED and lens is .5 inches. This is most easily seen in the end view of the drawing I posted. I know that using trig there is a way to figure this out. Anyone know?

david
1.73...that is the height to radius multiplier of a 120 degree lensed diode...
Say your driver is 2" away from the diode and a 1" height.

your LED cone radius (only need to deal w/ one side) is 1.73x 1 x = 1.73"

roughly the minimum distance (center of diode to edge of driver) of a 1" tall object from not impacting the light cone.
The tangent function is your friend...
 

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OK I'm using 60 degree lenses so I'm good. This means I can put the driver in the light like I wanted.

I also got the wire I ordered today, which I wont need :)

david

1.73...that is the height to radius multiplier of a 120 degree lensed diode...
Say your driver is 2" away from the diode and a 1" height.

your LED cone radius (only need to deal w/ one side) is 1.73x 1 x = 1.73"

roughly the minimum distance (center of diode to edge of driver) of a 1" tall object from not impacting the light cone.
The tangent function is your friend...
Got the LEDs all laid out, got the nuts in the slots and screwed a couple down. The screw heads are very close to the pads on the LEDs, but the meter says they are open.

Went to get my Arctic Silver 5, and can't find it anywhere. Now I get to wait for Amazon to send me some :(

david
 

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Discussion Starter · #8 ·
Got my thermal compound and a bit of time so I got the LEDs mounted to the heatsink.

Close up of CW and WW.



Close up of the individual wired LEDs



Overall



Each LED lights up, no shorts.

I've gone back to putting the drivers in the tank cabinet. The issue there is the size of the wire to deliver all the power in a single conductor pair. So using the wire I bought earlier.

Moving along,
david
 

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Discussion Starter · #9 · (Edited)
Got my lights hooked up to 48V power, and drivers.

I coded up a quick arduino uno sketch that reads an input and writes the output 0-255 to pwm pin 11.

I have 5 values
0, 25, 64, 102, 160, 255

For all 5 values I do see the light intensity change, but not by much, and there is always a flicker. Even at 255 (full bright), the LEDs flicker.

this happens for all 5 channels. Is the Uno just too slow to give smooth dimming?

Edit: Here is what I found on the PWM frequency:

Writes an analog value (PWM wave) to a pin. Can be used to light a LED at varying brightnesses or drive a motor at various speeds. After a call to analogWrite(), the pin will generate a steady square wave of the specified duty cycle until the next call to analogWrite() (or a call to digitalRead() or digitalWrite() on the same pin). The frequency of the PWM signal on most pins is approximately 490 Hz. On the Uno and similar boards, pins 5 and 6 have a frequency of approximately 980 Hz. Pins 3 and 11 on the Leonardo also run at 980 Hz.

Edit2: Nevermind, I didn't have the LED supply and Uno with a common ground. After fixing that . . . holy crap! Those LEDs are bright!

thanks
david
 

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Discussion Starter · #11 ·
Looking for ideas on how to manage the power supply and LDD driver board. My tank stand is full, I can't find a nice place to mount the power supply and board on the wall. I'm hesitant to put it on the bottom of the tank, next to the filter. Seems like a disaster waiting to happen.

I could mount it on the outside, back of the tank, plenty of room there. Curious as to what others think. It would be difficult to service as I would have to drain the tank, pull it out, to get to it. That isn't appealing. I may be able to mount it on the top of the tank bottom, or underneath where the tank sits. It would be out of sight, a bit awkward to work on, but easier than on the back.

Do I print up a case for the supply and board, as a single entity? Too many questions. Hopefully you will have suggestions, and insight that will help.

david
 

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LDD's run cool, I've put several in re-purposed plastic Hoffman enclosures.

All my power supplies thus far are mounted on 35mm din rail in the stands.
PS's create a lot more heat too.
 

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Discussion Starter · #13 ·
the only place I could put this in the stand is to hang it from the top. I made a couple of hanger to hold the power supply and then a couple inches above that the LDD board.



Hoping this will work OK for me.

david
 

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Discussion Starter · #14 ·
I got it all hooked to the iAqua controller and it works! I still need to figure out the scheduling, but I was able to define the different colors and everything. Now I have to create something to hang the fixture from, install the lenses, and hand the power supply in the stand.

david
 

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Discussion Starter · #15 ·
For hanging the fixture from the back wall, I'm thinking two of these:



The 15" puts it right in the middle of the tank. I have the hanger kit from MakersLED and the light isn't very heavy.

what do you think? Other ideas? I can't hang from the ceiling because it is two stories where the tank is.

david
 

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Discussion Starter · #16 ·
I hooked the light up to my iAqua controller and programmed the different lighting scenes. I had the light run all day. The ramping was very smooth, i couldn't see any change in light intensity, it was very smooth. During the midday scene where I have CW and WW at 100% the light became slightly warm to the touch. That was encouraging no way I'll need a fan.

I did hold it above the tank to compare, with my eye, the light intensity compared to the 2x96W PC light I have now. I'm not sure that the LED light is as bright appearing. I'll have to ask around and see if anyone in the Austin area has a PAR meter they wouldn't mind coming by to get come measurements.

Overall happy with what I have at this time. I hope to get it installed an swap out my old light next week.

david
 

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Discussion Starter · #17 · (Edited)
Finally back at it. I got it hung, here are a couple more picts





I was afraid it would look weird by the picture, but I think it framed it OK. I got an "ok" from my wife . . .

Still need to center the light, which also includes moving the tank to the left 1" as it isn't perfect in the alcove either.

david
 
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