I'm sure that would work fine if you use CREE XRE, Bridgelux or Epistar. Maybe still a little overkill if you use CREE XPG/XPE-- that would be the equivalent of almost 7 AI units.
LED Design
- Thread starter giulianom
- Start date
What do you think about this arrangement, with the three 10"x18" heatsinks centered across the tank?
The height of the LEDs would be roughly 6-8" above top of the tank, which is clear 3/4" acrylic with clear 1/4" lexan covers.
Do you think I would get adequate light coverage?
With or without optics?
The heatsink framework is 11" wide, and there would be exactly 5.75" of open space on either side of the heatsinks...
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The height of the LEDs would be roughly 6-8" above top of the tank, which is clear 3/4" acrylic with clear 1/4" lexan covers.
Do you think I would get adequate light coverage?
With or without optics?
The heatsink framework is 11" wide, and there would be exactly 5.75" of open space on either side of the heatsinks...
I would go with optics. They will keep the light directed down where you want it and not against the sides of your tank where it will just contribute to algae growth. Just draw the angles based on your setup to see which optics you need. I used 70 degree on my setup.
The gap in the front and back shouldn't be an issue because your lights are high enough.
The gap in the front and back shouldn't be an issue because your lights are high enough.
So I modified the arrangement some more, shrinking the circles to 2", with the LEDs being .8" instead of 1.0" - which appears to be the actual diameter of the LED stars.
Each heatsink is laid out with a 4 x 8 arrangement of 2" circles, 3 LEDs each.
So that would make it 96 LEDs of each color, or 288 LEDs in total.
I raised the fixture so that the LEDs are 7" above the tank, and drew out the angles.
The center two rows of LEDs with 30 degree optics would penetrate right down to the bottom without reaching much of the sides.
The outer rows of LEDs with 70 degree optics would spread out further, to about 3-4" below the surface of the water.. 90 degree optics would basically make it to the surface of the water.
And of course the light patterns overlap for coverage.
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Each heatsink is laid out with a 4 x 8 arrangement of 2" circles, 3 LEDs each.
So that would make it 96 LEDs of each color, or 288 LEDs in total.
I raised the fixture so that the LEDs are 7" above the tank, and drew out the angles.
The center two rows of LEDs with 30 degree optics would penetrate right down to the bottom without reaching much of the sides.
The outer rows of LEDs with 70 degree optics would spread out further, to about 3-4" below the surface of the water.. 90 degree optics would basically make it to the surface of the water.
And of course the light patterns overlap for coverage.
Something like this?
White?
http://cgi.ebay.com/1x-Super-High-Power-50-Watt-White-Led-Light-4000LM-/120630582090?pt=LH_DefaultDomain_0&hash=item1c16249b4a">http://cgi.ebay.com/1x-Super-High-Power-50-Watt-White-Led-Light-4000LM-/120630582090?pt=LH_DefaultDomain_0&hash=item1c16249b4a</a>
Blue
[IMG]http://cgi.ebay.com/2PC-50W-Watt-Blue-High-Power-Led-Light-Bulb-470nm-NEW-/190544436131?pt=LH_DefaultDomain_0&hash=item2c5d555ba3">http://cgi.ebay.com/2PC-50W-Watt-Blue-High-Power-Led-Light-Bulb-470nm-NEW-/190544436131?pt=LH_DefaultDomain_0&hash=item2c5d555ba3</a>
I am not sure about the blue one, I don't think the wavelength is that of Royal Blue...
Or a Cannon pendant?
[IMG]http://cgi.ebay.com/Cannon-LED-Pendant-453nm-Blue-50-watt-/300570164377?pt=LH_DefaultDomain_0&hash=item45fb60bc99">http://cgi.ebay.com/Cannon-LED-Pendant-453nm-Blue-50-watt-/300570164377?pt=LH_DefaultDomain_0&hash=item45fb60bc99</a>
Perhaps I could put a few of those large LEDs in the center line of the heatsink, and use the smaller 3W leds around the edges.
If you look at a spectral graph for "cool white" LEDs, there is a "peak" in the blue spectrum, but then a "hump" in the lower frequencies, which is what makes them look white and not blue.
20000k would be more blue than 14000k or 6000k, but still "white".
I found these oddly-shaped heatsinks on eBay for the 50W LED array chip:
http://cgi.ebay.com/Heat-Sink-20W-30W-50W-LED-/350472676746?_trksid=p4340.m263&_trkparms=algo%3DSIC%26its%3DI%252BC%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D10%26pmod%3D370494796097%26ps%3D63%26clkid%3D838241761089873068">http://cgi.ebay.com/Heat-Sink-20W-30W-50W-LED-/350472676746?_trksid=p4340.m263&_trkparms=algo%3DSIC%26its%3DI%252BC%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D10%26pmod%3D370494796097%26ps%3D63%26clkid%3D838241761089873068</a>
It seems rather small, but it's drilled and tapped for the LED array chips.
I'm not entirely sure what the flanges on the bottom are for... Mounting to a bar?
http://cgi.ebay.com/Heat-Sink-20W-30W-50W-LED-/350472676746?_trksid=p4340.m263&_trkparms=algo%3DSIC%26its%3DI%252BC%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D10%26pmod%3D370494796097%26ps%3D63%26clkid%3D838241761089873068">http://cgi.ebay.com/Heat-Sink-20W-30W-50W-LED-/350472676746?_trksid=p4340.m263&_trkparms=algo%3DSIC%26its%3DI%252BC%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D10%26pmod%3D370494796097%26ps%3D63%26clkid%3D838241761089873068</a>
It seems rather small, but it's drilled and tapped for the LED array chips.
I'm not entirely sure what the flanges on the bottom are for... Mounting to a bar?
I was thinking, would it be a good idea to have a mix of 50W 10000K LED and 50W 20000K LED chips?
10000K:
http://cgi.ebay.com/50W-10000K-High-Power-4000LM-LED-Panel-Aquarium-/270723067230?pt=LH_DefaultDomain_0&hash=item3f085a2d5e">http://cgi.ebay.com/50W-10000K-High-Power-4000LM-LED-Panel-Aquarium-/270723067230?pt=LH_DefaultDomain_0&hash=item3f085a2d5e</a>
20000K:
[IMG]http://cgi.ebay.com/50W-20000K-High-Power-4000LM-LED-Panel-Aquarium-/270738329590?pt=LH_DefaultDomain_0&hash=item3f09430ff6">http://cgi.ebay.com/50W-20000K-High-Power-4000LM-LED-Panel-Aquarium-/270738329590?pt=LH_DefaultDomain_0&hash=item3f09430ff6</a>
Also, lenses:
60 degree:
[IMG]http://cgi.ebay.com/45mm-Lens-Reflector-Base-20-50W-LED-Lamp-Blub-/220738462299?pt=LH_DefaultDomain_0&hash=item336509a25b">http://cgi.ebay.com/45mm-Lens-Reflector-Base-20-50W-LED-Lamp-Blub-/220738462299?pt=LH_DefaultDomain_0&hash=item336509a25b</a>
90 degree:
[IMG]http://cgi.ebay.com/45mm-90-Lens-Base-20-50W-LED-Lamp-Blub-/220664135458?pt=LH_DefaultDomain_0&hash=item33609b7f22">http://cgi.ebay.com/45mm-90-Lens-Base-20-50W-LED-Lamp-Blub-/220664135458?pt=LH_DefaultDomain_0&hash=item33609b7f22</a>
Also, apparently with the heatsink, you can mount an 80mm fan on the side.
10000K:
http://cgi.ebay.com/50W-10000K-High-Power-4000LM-LED-Panel-Aquarium-/270723067230?pt=LH_DefaultDomain_0&hash=item3f085a2d5e">http://cgi.ebay.com/50W-10000K-High-Power-4000LM-LED-Panel-Aquarium-/270723067230?pt=LH_DefaultDomain_0&hash=item3f085a2d5e</a>
20000K:
[IMG]http://cgi.ebay.com/50W-20000K-High-Power-4000LM-LED-Panel-Aquarium-/270738329590?pt=LH_DefaultDomain_0&hash=item3f09430ff6">http://cgi.ebay.com/50W-20000K-High-Power-4000LM-LED-Panel-Aquarium-/270738329590?pt=LH_DefaultDomain_0&hash=item3f09430ff6</a>
Also, lenses:
60 degree:
[IMG]http://cgi.ebay.com/45mm-Lens-Reflector-Base-20-50W-LED-Lamp-Blub-/220738462299?pt=LH_DefaultDomain_0&hash=item336509a25b">http://cgi.ebay.com/45mm-Lens-Reflector-Base-20-50W-LED-Lamp-Blub-/220738462299?pt=LH_DefaultDomain_0&hash=item336509a25b</a>
90 degree:
[IMG]http://cgi.ebay.com/45mm-90-Lens-Base-20-50W-LED-Lamp-Blub-/220664135458?pt=LH_DefaultDomain_0&hash=item33609b7f22">http://cgi.ebay.com/45mm-90-Lens-Base-20-50W-LED-Lamp-Blub-/220664135458?pt=LH_DefaultDomain_0&hash=item33609b7f22</a>
Also, apparently with the heatsink, you can mount an 80mm fan on the side.
I'd order one and test it out before you planned a whole setup based on it. Or go see Amici's.
Decided to bite the bullet and order some parts to make a 50W 20000K pendant to start with.
Ordered:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250825245867">1pcs High Power 50W White LED 4000LM Saving Lamp Light </a>
50W, 20000K LED Array chip. 140 degree spread by itself.
[IMG]http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250828846387">Power 50W Waterproof Bulb Led IP67 30-35V 1.5A Driver </a>
Driver, not dimmable... but it's a start.
[IMG]http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130417087135">LGA 775 CPU Heatsink w/Fan</a>
The LGA 775 chip size is just about the same size as the LED Array chip.
[IMG]http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220738462299">45mm 60 Degree reflector & lens</a>
Figured I'd start with a 60 degree lens.
Ordered:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250825245867">1pcs High Power 50W White LED 4000LM Saving Lamp Light </a>
50W, 20000K LED Array chip. 140 degree spread by itself.
[IMG]http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250828846387">Power 50W Waterproof Bulb Led IP67 30-35V 1.5A Driver </a>
Driver, not dimmable... but it's a start.
[IMG]http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130417087135">LGA 775 CPU Heatsink w/Fan</a>
The LGA 775 chip size is just about the same size as the LED Array chip.
[IMG]http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220738462299">45mm 60 Degree reflector & lens</a>
Figured I'd start with a 60 degree lens.
If you want, I can come over to compare the two LEDs, once my parts arrive.
Have you picked a driver yet?
There were a few dimmable ones, but not very many...
I made a model of a "standard" Intel LGA 775 Heatsink - they're cheap, easily available, and can cool roughly 80-90W of heat with a fan.
Played around with the idea of using 5 x 50W LED chips as a spot light bar.
58.5" x 4.125" x 1" aluminum angle, mitered and brazed or alumiwelded corners.
With 5 of the more or less standard Intel LGA 775 CPU heatsinks, which will be bolted to the frame. Heatsink fans will also be in place, on top.
The LED chips will be attached to the underside of the heatsink, where a CPU would normally go.
>
alt="" /></a>
Top view of the aquarium canopy, 6" off the top of the tank, or 8" from the water.
>
alt="" /></a>
Depending on the spread of the beams with the lenses, I may or may not decide to lose the center LED pendant.
The framework also leaves me plenty of room in the canopy for auxilliary lighting, if I want to add on the 1w/3w LEDs for moonlighting, etc..
58.5" x 4.125" x 1" aluminum angle, mitered and brazed or alumiwelded corners.
With 5 of the more or less standard Intel LGA 775 CPU heatsinks, which will be bolted to the frame. Heatsink fans will also be in place, on top.
The LED chips will be attached to the underside of the heatsink, where a CPU would normally go.
Top view of the aquarium canopy, 6" off the top of the tank, or 8" from the water.
Depending on the spread of the beams with the lenses, I may or may not decide to lose the center LED pendant.
The framework also leaves me plenty of room in the canopy for auxilliary lighting, if I want to add on the 1w/3w LEDs for moonlighting, etc..
So here's a thought I was having...
I am having difficulty finding a 50W driver that outputs 30-34 volts @ 1500mA, AND is dimmable.
The only drivers I can find that are dimmable, are 100W:
http://cgi.ebay.com/Dimmable-100W-High-Power-LED-Driver-Waterproof-Dimmer-/360375020910">http://cgi.ebay.com/Dimmable-100W-High-Power-LED-Driver-Waterproof-Dimmer-/360375020910</a>
Could I use one to drive two 50W LEDs, both running at 1500mA (constant current)?
I would think I could, if I wired the two LEDs in series - 3000mA divided across two 1500mA LEDs.
Or perhaps if I wired them in parallel, instead? My Ohm's Law is a little fuzzy.. :)
I am having difficulty finding a 50W driver that outputs 30-34 volts @ 1500mA, AND is dimmable.
The only drivers I can find that are dimmable, are 100W:
http://cgi.ebay.com/Dimmable-100W-High-Power-LED-Driver-Waterproof-Dimmer-/360375020910">http://cgi.ebay.com/Dimmable-100W-High-Power-LED-Driver-Waterproof-Dimmer-/360375020910</a>
Could I use one to drive two 50W LEDs, both running at 1500mA (constant current)?
I would think I could, if I wired the two LEDs in series - 3000mA divided across two 1500mA LEDs.
Or perhaps if I wired them in parallel, instead? My Ohm's Law is a little fuzzy.. :)
Yeah, I don't think that the 100W 3A driver would work..
This is the 50W 1.5A driver that I ordered:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250828846387">http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250828846387</a>
I wonder if it's possible to modify it to make it dimmable...
They're waterproof, so they're probably sealed.
Or could I put a rotary dimmer before the driver, on the A/C line?
Like you would find in a house to dim normal lights.
This is the 50W 1.5A driver that I ordered:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250828846387">http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250828846387</a>
I wonder if it's possible to modify it to make it dimmable...
They're waterproof, so they're probably sealed.
Or could I put a rotary dimmer before the driver, on the A/C line?
Like you would find in a house to dim normal lights.
If I am correct, voltage to an LED is all or nothing unlike a conventional light bulb that will dim with less voltage. Consider using PWM to dim and your problem will more than likely be solved.
Couple links to steer you in the right direction...
http://www.reuk.co.uk/LED-Dimmer-Circuit.htm">http://www.reuk.co.uk/LED-Dimmer-Circuit.htm</a>
[IMG]http://www.lunaraccents.com/technology-LED-truck-lights-dimming.html">http://www.lunaraccents.com/technology-LED-truck-lights-dimming.html</a> I know your not doing truck lights but the principle remains the same.
Couple links to steer you in the right direction...
http://www.reuk.co.uk/LED-Dimmer-Circuit.htm">http://www.reuk.co.uk/LED-Dimmer-Circuit.htm</a>
[IMG]http://www.lunaraccents.com/technology-LED-truck-lights-dimming.html">http://www.lunaraccents.com/technology-LED-truck-lights-dimming.html</a> I know your not doing truck lights but the principle remains the same.
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