So you want to play around with LED technology but don't want to fork over the big $$$. Well you have come to the right place!
LEDs are not a new technology, but they are new to the growing scene and many have been slow to adopt due to the high cost. The small amount of people using LEDs also contributes to the small amount of information we know about them, so I think it's time to change that! By coming up with a design that was easy to make and much cheaper there should be no excuse to not test your own and see what results you get!
In order to keep the costs as low as I could I resulted to eBay *cringe* but everything is A-OK as far as I can tell. The basic design will be that we mount the LEDs to the bottom of our heatsink, fans on top of the heatsink, and then mount the driver to its best fit on the heatsink. We will be using the 3Watt LED, although watts aren't a good way to describe LED power. This would be because for an LED to function properly it requires a certain Forward Voltage(vF) and Current(amperage). A 3Watt LED usually just means that it requires about 700ma at whatever the vF for that particular color is. All LEDs even ones that are the same color will require a slightly different vF while they all will require the same 700ma, this is where the driver comes in to play. For LEDs a constant current driver is used so that the current will remain the same in each LED while allowing the voltage to fluctuate to accommodate all the different vF required by your LEDs.
In order for people to switch to a new technology, they need a reason right? Well besides some of the already discussed reasons like lower wattage and lower heat there are a few others. For instance, the typical light is omni directional and even with good reflectors there is going to be some light loss. Well LED's produce light in pretty much one direction, thereby not wasting any watts on areas you don't want covered. Also with a normal light there is a lot of the spectrum that is produced that isn't heavily absorbed by the plants, but LEDs emit light in only a tight range utilizing all the watts more efficiently and allowing a targeted spectrum for certain plants. They are also small in size so this increases the places and arrangements can be put in. And the LED emitters themselves can be relatively cheap and easy to replace if a single unit fails.
Check out this page as well
-LED Driver (Note: You will need 10 LEDs minimum more on that later)
-660nm Deep Red LED
-620-630nm Red-Orange LED
-445nm Blue LED
-460-465nm Blue LED
-12,000K White LED
-Male end two pronged cord
Tools of the Trade:
-Hot Glue Gun
Step by Step:
1.) Gather your parts, for the sake of this tutorial we shall go with a 10 LED setup and use the driver listed. At this point this is when you want to decide how to blend your spectrum I encourage people to play around with the ratio themselves. I used 5 Deep Reds, 2 Red-Orange, 2 Blue(445nm), and 1 Blue(460nm).
2.) Follow this generic wiring diagram for your LEDs. You may need to do a different shape but that isn't important, wiring the LEDs serially is important, this ensures that the current is the same throughout all the LEDs and doesn't overdrive/underdrive any. Attach the LEDs to the heatsink with either thermal tape or whatever is at your disposal. I used hot glue because I will probably be modifying it in some way.
3.) Solder all the wiring for your LEDs together as well as shrink wrapping them afterwards. You should be left with one positive wire and negative wire on two separate LEDs and then proceed to solder that to the respective wires on your driver(LED out). Now if you wanted this is where you would want to add your lenses onto the LEDs to increase penetration while losing a bit of coverage.
4.) Attach your driver to the heatsink in whichever spot will suit your set-up the best, and now take the other two wires hanging from the driver(AC in) and wire them to your 120V standard two pronged cord that plugs into any outlet in the U.S. It doesn't matter which color wire goes to which because Alternating Current isn't flowing in a single direction.
5.) This is where you would attach a fan to the top of your heatsink, but I haven't done so on mine yet. All that is required is this tutorial.
6.) Plug it in and post a grow log! You can see my (Nearly) Finished D.I.Y. L.E.D. at the very bottom. To see how it performs compared to CFLs check out this thread!
I hope this tutorial has enough information in it so that anyone could assemble their own very similar to mine. Anything that you feel is missing or wrong let me know I do a lot of the so I forget little things. Enjoy!
Questions and comments very welcome
Edited by InsomniacFiles, 28 June 2011 - 12:44 PM.