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Re: Anyone experimenting with LED lighting?



>So is anyone experimenting with LED's (light emitting diodes)?
>Pros: Low power usage, low heat and long bulb life (100K hours)
>Cons: Expensive & lots of LED's required to make sufficient light.
>Seems like an interesting idea if it works.

>I was going to attempt to make a small lighting array but I can't find the
>instructions to make them anymore.  I remember reading a thread (in either
>reefcentral or reefs.org) about using LED's to light a tank but I can't
>seem to find the thread and the website that was on it seem to be down for
>the last week.

It's very easy. Just wire the LED's in series (and they are polarity
sensitive) until they get to an easy voltage to deal with (12 or 24 volts
usually), and then wire groups of LEDs like that in parallel. That allows
you to avoid the dropping resistors since the LEDs will usually want around
2.1v or so, although that varies with the LEDs - check your spec sheet.

You can get the LEDs from DigiKey (http://www.digikey.com), but the white
ones are expensive -- $3-5/each in small quantities if I remember right.
Surplus LEDs are cheaper but they are usually surplus due to color
variations that prevent them from being sold through regular channels.

>I was thinking of buying a 144 LED array (with super bright white LEDs,
>which are full spectrum 6500K) that the manufacturer says is equal to 150
>watts of light but it costs $200 (it may pay off really quick though
>because it will last 22 years of 12hr usage and the lower power consumption
>about 1/10th of conventional lights).

Hmmm. Might be an interesting expieriment. I had no idea anyone made an LED
array that was that potent. Chances are it is very, very directional as
well, which would actually be an advantage in an aquarium since that's what
you'd be trying to accomplish with the reflector of a normal light.

The only problem I can think of is the fact that LEDs tend to emit light in
very narrow bands (several peaks at certain wavelengths and almost nothing
everywhere else). The white LEDs I have are super-blue shifted too,
comparable to the 10000K MH lights around the perimeter with a lower-temp
white spot in the middle. Nice for a flashlight, but might look kinda wierd
on a tank.

     -Bill

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Waveform Technology
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