maddmatt02
Member
alright, I want to experiment with LEDs so I want to build myself a small LED unit to try and grow a plant to see how it goes, then maybe make myself some bigger ones for a real grow.
anyways I am going to buy a 4.5x6 blank perforated board, and a bunch of components and see what happens. but I need to make sure i am doing my math correctly (as well as if I am using the right formulas)
for argument sake, say I am going to use this LED - http://search.digikey.com/us/en/products/XPERED-L1-0000-00401/XPERED-L1-0000-00401DKR-ND/2446288, also for arguments sake say I want to throw 450ma current at them. 2.1 vf, <700ma
and using this circuit diagram - http://circuitsdiy.com/cheapest-high-power-led-driver-circuit-diagram
I am unsure of how to wire 2 leds to this (i think 2 of these would be the max), do I wire them series and do the calulations with a 4.2 volt drop, still using the 450ma current. Or should I do the calculations with the LEDs in parallel with a voltage drop of 2.1 but a current of 900ma? I have a feeling I could do it either way, and my choice would lie in would I rather throw 4.2v 450ma or 2.1v 900ma at one LED if the other should decide to give out. but for some reason part of me still thinks it might be 4.2v 900ma, although I am 99% sure thats wrong.
so say the series way is correct, and my regulator puts out 5v at a max of 1A,
.8Vx.45A=.36W and .8V/.45A=1.77ohm so I would get this 1.8ohm .333W resistor - http://search.digikey.com/us/en/products/4-1623930-7/4-1623930-7-ND/2380588 obviously I would need to find somewhere I dont need to buy 4k of the damn things.
I was thinking of putting 2 rows of 3 on the outside, and a row of 2 down the middle(6 reds, 2 blue). its going to be real small with not much output but I only have 3 plants going and my luck at least 2 will be male so most likely this is only going to have to grow one lone plant.
anyways I am going to buy a 4.5x6 blank perforated board, and a bunch of components and see what happens. but I need to make sure i am doing my math correctly (as well as if I am using the right formulas)
for argument sake, say I am going to use this LED - http://search.digikey.com/us/en/products/XPERED-L1-0000-00401/XPERED-L1-0000-00401DKR-ND/2446288, also for arguments sake say I want to throw 450ma current at them. 2.1 vf, <700ma
and using this circuit diagram - http://circuitsdiy.com/cheapest-high-power-led-driver-circuit-diagram
I am unsure of how to wire 2 leds to this (i think 2 of these would be the max), do I wire them series and do the calulations with a 4.2 volt drop, still using the 450ma current. Or should I do the calculations with the LEDs in parallel with a voltage drop of 2.1 but a current of 900ma? I have a feeling I could do it either way, and my choice would lie in would I rather throw 4.2v 450ma or 2.1v 900ma at one LED if the other should decide to give out. but for some reason part of me still thinks it might be 4.2v 900ma, although I am 99% sure thats wrong.
so say the series way is correct, and my regulator puts out 5v at a max of 1A,
.8Vx.45A=.36W and .8V/.45A=1.77ohm so I would get this 1.8ohm .333W resistor - http://search.digikey.com/us/en/products/4-1623930-7/4-1623930-7-ND/2380588 obviously I would need to find somewhere I dont need to buy 4k of the damn things.
I was thinking of putting 2 rows of 3 on the outside, and a row of 2 down the middle(6 reds, 2 blue). its going to be real small with not much output but I only have 3 plants going and my luck at least 2 will be male so most likely this is only going to have to grow one lone plant.