Hello there,
With my 15H nearing the end of it’s' cycle, I figured I would get ready for corals. And not just watching them during the day, but at night as well. The following is the first part of my project: the design and construction of a multi-color LED array.
**Design**
I started with some research on what wavelengths of light produce beautiful fluorescing corals. Among the advertisements and sales pitches, I found a few helpful articles. This one, http
/www.reefs.org/library/talklog/s_tyree_060202.html, was especially helpful, since it pretty much did my work for me! In Section II, a range of wavelengths that trigger the fluorescing pigments in corals, specifically stony corals. The ranges of wavelengths identified are 310 to 380 nm, 380 to 470 nm, 430 to 490 nm, 440 to 500 nm, 500 to 540 nm. Essentially 310nm to 540nm, or UV-A to Green
(1)
With this in mind, I selected three colors (wavelengths) of LEDs that fit into this range: Ultra Violet, at 390-400nm, Blue at 460-470nm, and Green at 515-530nm. Designing the array was fairly simple, see the following diagram:
Each color has its own switch, though not its own power supply. This allows me to turn each color off and on, though they will all have to run off the same timer if I so choose.
**Construction**
One ¼” x 1” x 22” piece of pine trim was marked at one inch intervals starting in the middle, with a total of 17 marks including the middle. After drilling each hole with a 7/32” bit, which fits the LEDs snuggly, I took a 1” drill bit and gave each hole a little bowl shape. This will help widen the beam of the LED, as they do not fit all the way through a ¼” piece of wood.
Once the drilling was finished, I lightly sanded the tip of each LED with 320 grit sandpaper. This will help to disperse the light even more, so I do not have spot lights, though it does sacrifice some intensity (probably). I then applied a generous amount of super glue gel to the sides of each LED and inserted them into the board, making sure that the positive lead was in the same position for each. This helps in the overall logistics of construction.
After allowing the glue to dry for four hours, I bent each lead as close to possible to the base. This was accomplished by gripping the lead with needle-nose pliers at the base and bending it down, away from the other lead, with your other hand. This will give a more compact look to the ‘unit’, though it is significantly harder to wire, but you can do it with patience.
Wiring time! I connected each pair of LEDs together, then connected all the negative leads together and ran a wire back to the “base” of the board. I wired a resistor to the positive lead of each pair, carefully wired each pair/set of colors together, and ran wires to the “base” of the board again. I now have four wires at the base, one negative, one blue, one green, one ultra violet.
The negative wire is connected to the negative lead from my power supply, a “3.7V” .35A AC to DC converter. I say “3.7V” because it actually reads 8.92V on a multimeter. Next, each of the positive (colored) leads it connected to its own switch, and each switch is wired to the positive lead from the power supply.
Here is what it looks like with all the lights on:
And here is the effect on the ceiling, the photo shows mostly blue, but there is certainly a hint of green in real life:
Unfortunately, my aquarium is at my parent’s house, so I cannot test this immediately, and I have two more weeks of school, so I’m afraid this is just a tease until then.
Any comments?
Cheers,
Marty
(1) http/www.solarscouts.com/games/Telescope/tlight.htm
With my 15H nearing the end of it’s' cycle, I figured I would get ready for corals. And not just watching them during the day, but at night as well. The following is the first part of my project: the design and construction of a multi-color LED array.
**Design**
I started with some research on what wavelengths of light produce beautiful fluorescing corals. Among the advertisements and sales pitches, I found a few helpful articles. This one, http
/www.reefs.org/library/talklog/s_tyree_060202.html, was especially helpful, since it pretty much did my work for me! In Section II, a range of wavelengths that trigger the fluorescing pigments in corals, specifically stony corals. The ranges of wavelengths identified are 310 to 380 nm, 380 to 470 nm, 430 to 490 nm, 440 to 500 nm, 500 to 540 nm. Essentially 310nm to 540nm, or UV-A to Green
With this in mind, I selected three colors (wavelengths) of LEDs that fit into this range: Ultra Violet, at 390-400nm, Blue at 460-470nm, and Green at 515-530nm. Designing the array was fairly simple, see the following diagram:
Each color has its own switch, though not its own power supply. This allows me to turn each color off and on, though they will all have to run off the same timer if I so choose.
**Construction**
One ¼” x 1” x 22” piece of pine trim was marked at one inch intervals starting in the middle, with a total of 17 marks including the middle. After drilling each hole with a 7/32” bit, which fits the LEDs snuggly, I took a 1” drill bit and gave each hole a little bowl shape. This will help widen the beam of the LED, as they do not fit all the way through a ¼” piece of wood.
Once the drilling was finished, I lightly sanded the tip of each LED with 320 grit sandpaper. This will help to disperse the light even more, so I do not have spot lights, though it does sacrifice some intensity (probably). I then applied a generous amount of super glue gel to the sides of each LED and inserted them into the board, making sure that the positive lead was in the same position for each. This helps in the overall logistics of construction.
After allowing the glue to dry for four hours, I bent each lead as close to possible to the base. This was accomplished by gripping the lead with needle-nose pliers at the base and bending it down, away from the other lead, with your other hand. This will give a more compact look to the ‘unit’, though it is significantly harder to wire, but you can do it with patience.
Wiring time! I connected each pair of LEDs together, then connected all the negative leads together and ran a wire back to the “base” of the board. I wired a resistor to the positive lead of each pair, carefully wired each pair/set of colors together, and ran wires to the “base” of the board again. I now have four wires at the base, one negative, one blue, one green, one ultra violet.
The negative wire is connected to the negative lead from my power supply, a “3.7V” .35A AC to DC converter. I say “3.7V” because it actually reads 8.92V on a multimeter. Next, each of the positive (colored) leads it connected to its own switch, and each switch is wired to the positive lead from the power supply.
Here is what it looks like with all the lights on:
And here is the effect on the ceiling, the photo shows mostly blue, but there is certainly a hint of green in real life:
Unfortunately, my aquarium is at my parent’s house, so I cannot test this immediately, and I have two more weeks of school, so I’m afraid this is just a tease until then.
Any comments?
Cheers,
Marty
(1) http
/www.solarscouts.com/games/Telescope/tlight.htm
