Hello Everyone!

I am new to this site and have done a lot of reading so far. I am wanting to make a grow light as others have done. I struggle with trying to understand all the items I will need and what lay out i should use. I am hoping i can gather some support from the experts in order to make this project a success. I want to do the following:

I have the pattern down (attached image) and i know what LED's i want. Can the experts help me with a diagram, drivers, powersupply, etc? I plan on odering a heatsink with fins that will be about 24 inches long and 8-10 inches wide.

I would like a dimmer for each set of colors and would like to wire two fans in the series as well. Any help you can provide will be greatly apprectiated.

LED's
http://www.ebay.com.au/itm/10PCS-3W-Royal-Blue-High-Power-LED-Emitter-700mA-450-455NM-with-20mm-Star-Base-/320867358141?pt=LH_DefaultDomain_0&hash=item4ab52f55bd
36 3W Blue with 20mm base
DC Forward Voltage (VF) DC3.4 ~ 3.8V
DC Forward Current (IF) 700mA
Wavelength 660nm

http://www.ebay.com.au/itm/10PCS-3W-Red-High-Power-660NM-Plant-Grow-LED-Emitter-Light-with-20mm-Star-Base-/320867389761?pt=LH_DefaultDomain_0&hash=item4ab52fd141
60 3W Red with 20mm base
DC Forward Voltage (VF) DC2.2 ~ 2.6V
DC Forward Current (IF) 750mA
Wavelength 660nm

 

I would like a dimmer for each set of colors...

That means you'll want each color under current control using PWM, the "normal" approach for what you're doing.

There's a daunting variety of LED drivers available commercially that will do this for you. Have you shopped around at all? You'll want a controller that can more than handle the total power requirement, and deliver the current your LEDs need. Looks like 700mA, though you might target a lower number to increase the life of your LEDs. (Don't design to use ANY component at its rated maximum.)

A critical design choice will be voltage. A higher voltage allows you to control more LEDs in series with a single, controlled current, and lowers the relative losses in any current-reducing resistors.

 

36 3W Blue with 20mm base
DC Forward Voltage (VF) DC3.4 ~ 3.8V
DC Forward Current (IF) 700mA
Wavelength 660nm

Your blue seems a bit red....

 

1-Run "series" strings (google it if you are unsure what is series vs parallel).
2-Add up the Max forward voltage rating of each LED in the string.
3-Find a "constant current" LED driver with a DC output voltage that equals or is greater than the answer to 2 and is rated to deliver 700mA (or less)
(hint.. many of the drivers only go to 48 or 54 volts for safety reasons so you will be limited to a dozen or so LED's per string.. but there are many that go higher..use caution)
4-Ensure that driver has dimming capabilities.. (I always use the ones with "3 in 1" dimming that accept analog 1-10V or 0-10V PWM or resistance like a simple 100K potentiometer for dimming)

(Try meanwell.com for very good quality/well known enclosed drivers like the LPF series or similar)

oh and for the fans just get 2 x 12V fans and a 12V wall-wart type power supply (constant voltage this time) with a rating greater (a good bit greater for safety factor.. 1.5 times or more is good) that the current requirements of the fans added together.. fans on their own circuit..

 

Not to steal steal the OPs thread and maybe the OP has an idea or will learn from the question.

How are wires soldered to these leds? Won't the heatsink make soldering difficult? I assume the wires are soldered directly to the marked pads?

 

Not to steal steal the OPs thread and maybe the OP has an idea or will learn from the question.

How are wires soldered to these leds? Won't the heatsink make soldering difficult? I assume the wires are soldered directly to the marked pads?

You just solder the wires to the exposed pads.. Done ALL the time. And yes the MCPCB makes it difficult.. A good higher power soldering iron is needed. (or solderless LED sockets for star mounted PCB's )

 

OK, so i am going to jot down all the drivers i find and will report back to you guys. The response you all have given so far is amazing. Thanks for the input.

So, if i want a fan, did i read right that i would need a separate power supply for constent voltage?

Do i need resistors or anything else for that matter? If i understand correctly all i need is LEDs, Drivers (for each series of LEDs), two power supplies (one for constant current and one for constant voltage), Conductive bonding agent, Heat Sink and some fans?

Thanks so much for the help.

 

So, if i want a fan, did i read right that i would need a separate power supply for constent voltage?

Do i need resistors or anything else for that matter? If i understand correctly all i need is LEDs, Drivers (for each series of LEDs), two power supplies (one for constant current and one for constant voltage), Conductive bonding agent, Heat Sink and some fans?

Thanks so much for the help.

yes a constant voltage supply (like a wall wart) is used for the fans.

No resistors are needed with constant current LED drivers.

I hope you are aware that LED drivers arent' cheap at all... Mostly $20-40 each per series string.. Going with "cheaper" Chinese drivers on ebay is too risky IMO.

I will only ever use Meanwell. (But I'm not afraid to spend some money either to do it right)
My current DIY LED setup for my 120 Gallon saltwater reef tank will cost me around $450 and consists of 200W of LED's/active Nuventix Synjet heatsinks/meanwell drivers

 

McGyvr, BTW are you the real McGyver. LOL.

I have been a saltwater enthusiast/hobbiest for over 20 years. I recently moved and down graded from a 300 gallon to a 75 gallon. i currently run the Skyye LED Tablet on my tank and it is awesome. My mom has been using HIDs to grow lettuce, tomatos and so forth. Her energy bill is huge so i wanted to kick it down a little bit and go with some LEDs. Besides i love projects.

Do you have a build thread on your LED lights? From what i understand i can buy a driver that will power 12 LEDs right? Yikes, thats 9 LED drivers. UGH! What would a 150W 50 X 3w LEDs be equal too as compared to HID? Would the 150 with 90 degree lenses be good enough to hover 18 inches over a 4'X2' grow area and crank out some veggies?

 

From what I've seen
100W of LED is roughly equivalent to 250W metal halides...
IMO 150W of LED's is plenty for 8sq ft of "veggies" All reds 660nm and blues like you are doing should be just fine.. The plants should look almost black under that light which is rather neat but will grow like crazy.

No real build thread on my fixture. BUT I use 50W multichip LEDs instead of multiple 3W Crees, meanwell LPF-60H-36 drivers and Nuventix 60W active heatsinks (PWM membrane instead of a fan..its really neat and sounds like a small air pump for a fish tank) It runs only 12 deg C over ambient when pushing 50W and I actually run no optics now but might add some 90 deg in the future.

Now you can save "considerable" amounts of money doing series/parallel builds BUT risk thermal runaway. However a fast blow pico fuse is a rather simple solution to add into each series string to prevent those problems. (not the best but can be done and really works just fine as a just in case)

With a series parallel build you can do 2 (or more) series strings in parallel with a larger driver.. But the current rating of the driver is "roughly" divided by the number of series strings.. So lets say you have a 5A rated driver and 5 series strings of 12 LEDs.. Each series string will then get 1A each (in a perfect world) But that way its only 1 driver for 60 LEDs.
But other than mentioning it here I'm against parallel builds (or wont recommend/discuss them to those that aren't 100% aware of the issues)

 

Thats awesome. I think 150W would do the trick. As far as the parallel, I dont want anything to do with that. I dont mind spending money in order to do it correctly so i am going to go shopping (online) and i will let you know what i come up with. Thanks!

 

OK, sounds great. I am going to do some shopping online and will list the parts before i buy. Thanks for the help.