Come in and join me....

[sjmusic2]

I'm not familiar with Arduino, but just googled it and it looks more straight forward than other mcu's !

 

As I'm not good at programming with C, I have a BASIC compiler (mikroBASIC) which should make it a lot easier. It also possesses a library of commands and routines which will come in handy.

[evilc66]

Cool. Thats kind of how the Arduino's are set up. Kind of like an "MCU for Dummies".

[coolwaters]

they evilc66 wats the best peak wavelength of coral again?

 

should i get the regular blue (465 – 485nm) or Royal blue (450 – 465nm)?

 

this next one is going to best me about $70 shipped....my friend is giving me his old aluminum CPU heat sink.

 

im going all Cree for this one.

Cree MCE Multichip Power LED looks pretty cool. and at cutter theres WA+ bins. so the color temp is going to be around 9k+ that really cuts down on the blue LED usage.

 

also its the M-bin so instead of 370lumen is 430 =p

well worth the $30. 107lm/w is crazy.

[evilc66]

Royal Blue will be closer to the UV spectrum so corals will fluoresce more, and is closer to the photosynthetic peak response for the coral.

[sweevo]

Great thread guys, i've read it all !!!!

 

This has really got me thinking. I haven't done electronics since I left college 20 years ago but by and large I think I may be able to have a go at making a prototype of my own, time permitting.

 

Keep up the good work and more importantly, keep posting !

[evilc66]

Go for it. You know wher to find us if you have questions. I have access to heatsink if you need them.

[PBUEHH]

wow, pretty wild stuff there. If i ever DIY LEDs im comming back to this thread.

[evilc66]

Thanks. I appreciate that.

[davidncbrown]

Still tagging along... Ton's of great ideas evilc66, I just decided to get a sunpod and I'm going to replace the stock led's with 4 rebel stars each of 3 royal blue luxeon rebels. I'm really looking forward to that actinic look they give the tank.

[evilc66]

That should be pretty cool. Just make sure you cool them appropriately, but you knew that already

[davidncbrown]

Ya good point. I'm going to remove the stock panels that the led's are on and replace them with new panels with the rebel stars attached. I'm thinking a small pentium computer heatsink would cool them sufficiently. Any advice on how I should orient the led's? I figured I would just do 2 on each side and keep them inline with the MH lamp. I'm sure they will cover the whole tank because I have two in my current hood which is closer to the surface of the water and they make a load of difference. I can't wait until led lighting gets affordable. It's so much safer and more efficient than running those high wattage MH bulbs too.

[evilc66]

I was thingking the same thing about the heatsink. I'm sure there is one that is fairly close in size that would almost drop in.

 

For orientation, I think I would actually go perpendicular to the MH. Get a little better coverage from to back. Or, you could put them on opposite corners of the heatsink. Get the best of both worlds.

[davidncbrown]

I was thingking the same thing about the heatsink. I'm sure there is one that is fairly close in size that would almost drop in.

 

For orientation, I think I would actually go perpendicular to the MH. Get a little better coverage from to back. Or, you could put them on opposite corners of the heatsink. Get the best of both worlds.

 

 

Like this? Pardon my 16-bit color microsoft paint drawing.

[evilc66]

Exactly.

[davidncbrown]

Exactly.

Cool. Thanks evil, I'm probably going to be buying the sunpod next week and the led's the following week. I'll make a thread about it, hopefully it works to my lighting.

[evilc66]

Keep us posted.

[sweevo]

Hi Evilc66, just had a track back through this thread and haven't found anything on cooling. Are your LED's still passively cooled with just the heat sink?

 

I've picked up a couple of second hand heatsinks on the cheap to play around with and just wondered if you were now using fan cooling since cranking the power up to 64W? I'm pretty sure originally you were just using the heatsink alone for cooling but haven't seen any mention of fans since increasing up to 27 LED's.

[evilc66]

I always had a fan on the heatsink, but it's just a low flow 80mm. I could technically go without one, but the temperatures got to a point where I was a little uncomfortable. At least I know that if the fan fails the array isn't toast.

[Ryan110484]

Hi evil-

 

I've been researching LED's for lighting a reef for over a year now and came across your this thread quite some time ago. I must say it is one of the best DIY's out there when it comes to showing others what to do. I had a question on the constant current circuit that you are using. I have been planning my system for awhile now and have finally settled on building one that will have 36 white leds. (I will add the blue later) After looking through all of the comments on Dan's instructables I have still not been able to find an answer to my question so I was wondering if you might know. The circuit that I am planning on using is rated for 5-28v and up to 5 amps. I am going to get a 24v power supply and would like to have one driver power my leds in series of 6 with 6 parallels. Now on to my question. According to Dan this circuit will work, but would I solve the resistors for the total amps in series which is 700mA or for the total amount of current that is being drawn from all of the parallels which is 4.2 amps? Would you recommend a different combination of series/parallel? Should I just run one driver for each series of 6?

 

I hope I explained myself well enough in that.

[jpndave]

Well, I FINALLY have my Rebel's ready to go. I have a refugium light and main light for a BC8 that just need to be attached and connected. Hopefully tomorrow. Both are done out of billet aluminum and finned to heat sink. I'll post pics as soon as I fire them up.

 

The combination I am looking at using for the tank is:

 

Part

5 CW (Cool White) @ LXML-PWC1-0100 180 lumens @ 700mA 6500K

4 WW (Warm White) @ LXML-PWW1-0060 110 lumens @ 700mA 3100 K

6 RB (Royal Blue) @ LXML-PR01-0275 525mW @ 700mA 455 nm

 

I have extra of all the different LED chips so I can tune it in a bit. I can also cut back the input or increase as necessary, they are on separate circuits for the most part (5 CW, 5 RB, 1 RB & 4 WW). I am hoping to strike a balance with the colors, bring out the reds a bit more with the WW and hit between 15K & 20K overall. What do you think, too much of something, not enough?

 

The refugium is 3 of the WW.

 

I have really enjoyed following along here and hopefully can now add to the thread a bit more.

 

Thanks,

 

Dave

[evilc66]

Dave, sounds great. Can't wait to see pictures.

 

Ryan, you have to size the resistor for your total current, so for you, 4.8A. That circuit may not be the best idea if you are looking to run it at that high of a current. It will get very hot, as it is really still just a linear regulator (read: inneficient). Is there a reason why you are not splitting the circuit up into multiple drivers (one for each series string)? That will reduce the heat on the FET and the current limiting resistor. The parts for that circuit are so cheap that it doesn't make sense to cram every LED onto one driver. Plus, now you have more control over the current to each string of LEDs.

 

For me, that driver running at 700mA gets warm to the touch with a heatsink. Running it at close to 5A will get nuclear temperatures.

[Ryan110484]

I was worried that it might get too hot doing it that way. The reason I wanted to run them off of one circuit is because it is a variable resistor circuit and I didn't want to have 6 different pots just to control the white LEDs. Unless I can find something else to control the brightness, I will just switch it to one driver per line without the control for brightness.

[jpndave]

I was worried that it might get too hot doing it that way. The reason I wanted to run them off of one circuit is because it is a variable resistor circuit and I didn't want to have 6 different pots just to control the white LEDs. Unless I can find something else to control the brightness, I will just switch it to one driver per line without the control for brightness.

Check out this:

http://www.instructables.com/id/Circuits-f...ED_s/?ALLSTEPS#

 

And this (the one I am using):

http://www.instructables.com/id/Power-LED_...rent/?ALLSTEPS#

 

I wouldn't just use a resistor when these are so simple and inexpensive. And, if you size the powersupply voltage and array properly, very efficient.

 

HTH,

 

Dave

[Ryan110484]

Check out this:

http://www.instructables.com/id/Circuits-f...ED_s/?ALLSTEPS#

 

And this (the one I am using):

http://www.instructables.com/id/Power-LED_...rent/?ALLSTEPS#

 

I wouldn't just use a resistor when these are so simple and inexpensive. And, if you size the powersupply voltage and array properly, very efficient.

 

HTH,

 

Dave

 

http://www.instructables.com/id/EFKW3E8DAVEWIJM9ZS/

That is the circuit that I was looking at using. However, I am worried about the amount of current that would need to go through it to power all of the LEDs.

[evilc66]

They are all basically the same in the fact that they are linear regulators. Not one of them will be able to deal with that kind of amperage.

 

Ryan, there is nothing stopping you from using an external adjustment pot with multiple driver circuits. Use the set resistor to set the maximum current on each driver. Put the pot inline to each driver after the set resistor to increase the resistance. All you have to make sure is that the pot can handle the wattage for each of the drivers. In a linear regulator like this, the set resistor, and subsequently the adjustment pot, have to be able to take the burnoff that the LED isn't using.

 

A better alternative, albeit slightly harder to work with, is a circuit based on the ST Micro STCS1 driver. It's a buck driver that needs very few external parts. It's surface mount only though. I have built up a few of these drivers and they work great. Takes up to 40v @ 1.5A! The dimming control is a pwm input, which you can make from a 555 timer (look up "555 pwm"). You can tie all the inputs to the timer and dim using that. Very low current on that side of the circuit.