hi, I'm 'new' but i've been lurking here a while I have found this guide very interesting! I recently found some other useful posts on some other forums: http://www.gardenscure.com/420/lighting ... ray-2.html , http://www.icmag.com/ic/showthread.php?t=139586 and http://www.icmag.com/ic/showthread.php?t=108442

In the How to build your own LED array (first link) they are using golden dragon LEDs or golden dragon plus LEDs. The cheapest UK supplier I could find for these was http://uk.digikey.com/ especially if you are willing to buy in bulk. The cost halves if you order over 200 GD Plus LEDS (about £1.50 each + VAT). They sell Golden Dragons (not the plus ones) for 1.17£ but you need to order over 800! which would be a lot for me personally. Anyway, I'm wondering if the PLUS are worth price premium. What do you guys think of these LEDs?

eerr here's the LED specs http://catalog.osram-os.com/catalogue/c ... 4f037c0023

Hi

I don't know if theres anyone left here I know, either way I will not be replying to anything posted here. All the "feel" and knowledge is gone from this place, its not home anymore - shame.

B0fin

Well thats too bad..... I feel the PS will be in good hands with Lady Z and Draig.

I ain't going anywhere else but here.

b0fin you should really make a schematic for this; what ohm resistors are there?
I never used Veroboard in electronics class only alot of breadboarding but i see its basically the same except using a plastic material its copper strips going up and down.
So,453 is the best for vegging? 662 is the best for flowering?
If you could send me info on how to build it im electronically savy. 2nd year in electronics and we spent alot of time working with LED's on simple circuits like the 555 timer, JK Flip Flop, circuit building,magnetism,power supplys, diode bridge power supplies etc.
Im making a schematic for myself base on your designs so it'll be more info out there
I wanna make a PDF of all this info like a guide.

Here is 1 of the schematics i got done so far.

Red Light Array



All the schematics are the same except for the resistors, The LED's go positive lead, negative lead to positive lead, negative lead to postivie lead etc.
White LEDs.
3 leds with a 56 ohm resistor

Blues LED.
3 leds with a 56 ohm resistor

Reds LED.
4 leds with 2 x 220 ohms in parallel making 110 ohms

UV Leds.
3 leds with 82 ohm resistor

Tips:

When reading the schematic, the side without the flat side is the positive leadw

bofin good ta see ya! were still here, some of us!

Greetings all. I have read and reread this thread and have enjoyed it very much. Two things: First, Mr Fin has pointed it out several times Please please don't use voltage drive and a resistor to drive your strings of led's. To get close to max light out use matched led's and a current drive. You can get closer to the max power the led can take if you use a good quality current drive. Why? well temp in the grow room varies. With a change in temp comes a change in conductivity of the led's (really any bipolar device) so as the temp goes up the total resistance of the led string starts dropping and the current in the string starts to climb. Yes, the series resistor will drop more voltage but the total current will still rise in the string for the same applied voltage. And if you are close to the max current to start you will burn out led's. And as the current starts to climb the junction temp will rise because the rate of temperature diffusion into the heatsink will climb. That means that the junction temperature itself will climb because you need a bigger differnce in temp to xfer more energy across the junction. That means that the junction is hotter so the resistance goes down more and even more current flows.
And poof dead led's. One gets around this problem by building in a 10 % derating of the led. So a current drive will deliver more light because one can operate very close to the led's max current rating and it doesn't matter what the led junction resistance is because the drive will only deliver the set current to the string. Oh that is why you need to get the same bin for each led in a string. The second thing is that e = i x r. So, switching a 1000 watt light from 120 v to 240 v doesn't cut your power use in half. 1000 w = 1000 w. What it does is allow one to use the same wires and sockets but get twice the power from the system. For example. My 120 volt system will handle 20 amps but only 15 amps at any given socket. If the same socket is rated for 240 operation I can still only draw 20 amps total and 15 amps from that one socket. A 1000 w light draws approx 9 amps at 120 v and only 4.5 amps at 240. so one could have 2 lamps on the same line blah blah blah. There isn't any way to cut your power useage in half just by doubling the applied voltage. TANSTAAFL.
Tunnel