diy multichip led lights

[nige]

with the lenses you don't as much light spill I would think for a tank that length you might get away with two 30w led unless its a cube then you could use one hybrid with a 120deg lens but it will need to be at least 18" above the water another option would be multiple 10w but I think you get better shimmer the less light sources you have. also a lot less wiring with the multichip led and for those of use that may not be as electronically minded makes thing much simpler

[nige]

I have 32 3Watt LED's over my 40B and get very nice ripple, only 7 of them do not have optics. I have two strips, one with 14 and the back one with 18. Two blue in the front strip and 3 blue in the back one. Oh, and 7" off the water.

I know you will have shimmer with multiple led as I used to have a fitting over my old 5/2/2 but with the 3 lights over my tank now it looks more like sun light I will try and get a video done so you can see.

[kerry]

I thought about that after I posted, I figured you would have a longer wider slower ripple effect versus my shorter skinny faster ripple.

[jnad]

Tanks nige!

The tank acurate measure is :
31,5 inches long
15,75 inches wide
19,75 inches high

I cant find any 30w hybrid led, only 10,20,50W . I do find the 30w 20000k led, but i dont now if this color is almost the same as the hybrid led with Royal blue.

I am very sceptical about fans and noise, when looking at the internet it looks like with 10W leds and good heatsink i dont have to use fans, maybe i choose to go that route. I mean heatsink like this:

http://www.ebay.com/itm/New-Aluminiu...item3f103d07cb

Jnad

with the lenses you don't as much light spill I would think for a tank that length you might get away with two 30w led unless its a cube then you could use one hybrid with a 120deg lens but it will need to be at least 18" above the water another option would be multiple 10w but I think you get better shimmer the less light sources you have. also a lot less wiring with the multichip led and for those of use that may not be as electronically minded makes thing much simpler

[nige]

If your tank is only 19" high you will get away with 10w

[jnad]

How many 10w do you suggest? And would you choose the 20000K or the hybrid led with royal blue to Get the right coloring. This leds wil be the only light source over the tank.

jnad

If your tank is only 19" high you will get away with 10w

[nige]

I would go with 5 maybe 6 of the hybrid led's

[Floyd R Turbo]

Someone on our local site posted this

In the past I tried using cool white 50w leds on some pretty big heatsinks and fans. Also had multiple 10w blue bulbs. They burnt out in three months and degraded quickly. The 50w bulbs create soooo much heat...especially when left on all day.

After further research, I came to a conclusion that liquid cooling or heat sinks not readily available to the general public were the only way to construct a fixture that would last. Now...multiple 10 to 20w leds seem more of a reality and would be interested if someone constructed a fixture using these new multi color chip models.

Also, it seemed you really got hot spots on the coral with an led as large as a 50w. Can't imagine a 100w. My corals started bleaching almost immediately. Really lends toward the absolute need for dimming capability, which I didn't have. Dimming and the 15-20k bulbs make me interested to try multiple 10 and 20w options with lenses.

I have to imagine that there is some truth to this. cooling a 100W LED chip would be a difficult task I would think. I would think that the need for dimming would be crucial to take care of the coral bleaching aspect. So I wonder how you would go about dimming large LED like this, would there be any different considerations being that it is a multi-chip LED? Meaning, since you have more than one chip on the board, if you simply supply less current would you get less output, in the same fashion as if you had an equivalent string of 3W chips?

[kerry]

I know that 5 3W LED's on an AMD computer processor heat sink makes a huge amount of heat, hot enough I am surprised they have not burned out yet. I need to get the little fans on them because I feel this amount of heat could shorten the life of the LED's.

[kotlec]

Someone on our local site posted this



I have to imagine that there is some truth to this. cooling a 100W LED chip would be a difficult task I would think. I would think that the need for dimming would be crucial to take care of the coral bleaching aspect. So I wonder how you would go about dimming large LED like this, would there be any different considerations being that it is a multi-chip LED? Meaning, since you have more than one chip on the board, if you simply supply less current would you get less output, in the same fashion as if you had an equivalent string of 3W chips?

Dimming via lowering amperage is not useful at all as it has very low resolution and is ineffective and hardly achievable with this big leds. PWM is used to dim leds and there is no difference if bulbs are single or multi-chip. Appropriate driver is the key.