where to find a single 3w cree power supply

[jolson10450]

i have a mini 1g tank and i want to put a single 3w cool white cree in its lid rather than the incandescent light it comes with, i am looking for a power supply to run it. i am going to go with no optics because the tank is only 6" tall - sand bed and the led will be 1.5" from the water.

i want to make a micro nano with my mini GBTA's in it and 2 sexy anemone shrimp to live in them. maybe throw a few coral in it.

anyone know where i can get a power supply for it? can i just use a single 1 amp 12v power pack type of power supply?

[XSiVE]

most of the "easy" LED power supplies have a minimum output voltage, so if you wanted to run only one LED, you would have to put some resistors in line.

for example the LPC-35-700:
http://www.rapidled.com/servlet/the-3/driver-700ma-48v-drivers/Detail can run 3-12 of the 3.7Vf LEDs. Im not in the state of mind to do the math for you here, but you'd have to put some decent sized resistors in line if you wanted to just run one LED with it.

My suggestion.

Get that driver, get one cree XP-G cool white, get one or two cree XR-E royal blues, pack the 3 of them super tightly together on some sort of heat sink and go from there. The XP-G is about 30% brighter than the XR-E so you'll get about a 20k look (since you're displaying stuff this might be best anyway).. A single cool white LED over the tank will give you an extremely yellow look and I guarantee you wont like it.

If you only end up doing two, make sure you wire a proper resister inline that has a capacity of at least 5Watts, and I think it should be something like 5 ohms?? not positive.. vicodin from this tooth pull is making me hazy.

[jolson10450]

most of the "easy" LED power supplies have a minimum output voltage, so if you wanted to run only one LED, you would have to put some resistors in line.

for example the LPC-35-700:
http://www.rapidled.com/servlet/the-3/driver-700ma-48v-drivers/Detail can run 3-12 of the 3.7Vf LEDs. Im not in the state of mind to do the math for you here, but you'd have to put some decent sized resistors in line if you wanted to just run one LED with it.

My suggestion.

Get that driver, get one cree XP-G cool white, get one or two cree XR-E royal blues, pack the 3 of them super tightly together on some sort of heat sink and go from there. The XP-G is about 30% brighter than the XR-E so you'll get about a 20k look (since you're displaying stuff this might be best anyway).. A single cool white LED over the tank will give you an extremely yellow look and I guarantee you wont like it.

If you only end up doing two, make sure you wire a proper resister inline that has a capacity of at least 5Watts, and I think it should be something like 5 ohms?? not positive.. vicodin from this tooth pull is making me hazy.

alright hmm... ill see what i can do. i was hoping just to find a single power supply to wire diectly to a single LED. i might just do a RB instead of white. either way its going to pound light at the tank being only probably 4" of water above the sand bed. i find it a waste of money to do more than 1 led on a 1 g tank regardless of the color. i want to try to stick to 1 at this point and in the future if i dont like it or things aren't staying alive i might go with 2-3. i am going to do a 3 led over my 5.5g nano with 40 optics at 12" should cover it perfect. its only got a 12x8 footprint that actually needs lit.

i was even thinking of chopping up my old moonlights and putting the power supply from them on it. it should work just find depending on the amp rating on it.

how much amperage do you need for a single LED? can it be less than 1 amp? say 700 milliamp?

[XSiVE]

you could also use those single heatsinks you linked in chat no ptoblem, but mount them to something that would keep the lights in close proximity to one another... those are pretty small heatsinks, so you would want to be sure you had some active cooling.

[XSiVE]

these LEDs can be run from anywhere between some very low limit all the way up to like 1.5A, 700mA is the recommended current to keep the longest lifespan.

You WILL NOT like just one RB, it is insanely blue, no white color at all... not to mention it only generates one of the four acceptable wavelengths needed by zooxanthelle to properly photosynthesize. I know you want to the setup to be cheap but you're going to end up unsatisfied with a single LED no matter how you slice ir.

No offense intended here but I think your understanding of how an LED works is not complete. An LED works somewhat backward from a typical electric device, instead of drawing more curent as it needs more.. instead the current can be varied and it will have a larger voltage consumption (or voltage drop).. compare that to a typical electric motor like in our pumps that consumes a constant 120volts, as it has more resistance, because head pressure or whatever, etc, it draws more amps. See the difference?

So what happens is in the case of the LPC-35-700 constant current driver is that outputs a variable voltage of anywhere between 12 and 48 volts based on the voltage drop (resistance) it detects in the line. it will always push 700mA, but if you only have 3 LEDs on there it will supply ~12v, whereas if you have 12 it will supply ~48v.

Make sense?

[jolson10450]

these LEDs can be run from anywhere between some very low limit all the way up to like 1.5A, 700mA is the recommended current to keep the longest lifespan.

You WILL NOT like just one RB, it is insanely blue, no white color at all... not to mention it only generates one of the four acceptable wavelengths needed by zooxanthelle to properly photosynthesize. I know you want to the setup to be cheap but you're going to end up unsatisfied with a single LED no matter how you slice ir.

No offense intended here but I think your understanding of how an LED works is not complete. An LED works somewhat backward from a typical electric device, instead of drawing more curent as it needs more.. instead the current can be varied and it will have a larger voltage consumption (or voltage drop).. compare that to a typical electric motor like in our pumps that consumes a constant 120volts, as it has more resistance, because head pressure or whatever, etc, it draws more amps. See the difference?

So what happens is in the case of the LPC-35-700 constant current driver is that outputs a variable voltage of anywhere between 12 and 48 volts based on the voltage drop (resistance) it detects in the line. it will always push 700mA, but if you only have 3 LEDs on there it will supply ~12v, whereas if you have 12 it will supply ~48v.

Make sense?

yeah i understand i use LEDS at my work in a daily basis just have not dipped into cree's yet. we use basic 12v power supplies on our LEDS and just buy them depending on how man LEDS / amp needed. it is different from what you are saying though so i dont hardly understand. i do get that of course the more amps you add the higher the voltage will be depending upon resistance.

i am just not looking for something to make coral pop or anything. right now i have 6700 k cf lamps on my mantis tank and i think it looks fine. its a lot more yellow than my main but still its not the coral pop and blue i am looking for. i just need a light that will grow whats in it which are basic easy coral. i am going to do the same concept with this one. basic corals and stuff, nothing expensive. its just something to look over at while doing work. its an experiment.


this however has gotten off course from my original question. so i could use a 12v 700mA power supply to power one of the cree xr-e leds? that is all i want to know. i will handle the rest the way i choose.

[XSiVE]

this however has gotten off course from my original question. so i could use a 12v 700mA power supply to power one of the cree xr-e leds? that is all i want to know. i will handle the rest the way i choose.

any way you slice it, one of these CREE LEDs on a 12v source is going to need some resistors in line or you're going to fry it.

If you're talking about a typical 12v/700mA wall wart as a power source, Im really not sure how it will work. You can wire it up (with resistors) and put your ammeter in series to check the current that is being drawn. The 700mA rating on a wall wart is a max rating, not that it should continually be outputting that level of current.

[jolson10450]

any way you slice it, one of these CREE LEDs on a 12v source is going to need some resistors in line or you're going to fry it.

If you're talking about a typical 12v/700mA wall wart as a power source, Im really not sure how it will work. You can wire it up (with resistors) and put your ammeter in series to check the current that is being drawn. The 700mA rating on a wall wart is a max rating, not that it should continually be outputting that level of current.

so the smallest i can go without resistors would be 3 leds?

what about this if i use this
http://ledsupply.com/03023-d-n-500.php
500mA driver at 3w would pull 6volts and the minimum for that is 5 volts. would it work for 1 led?

[XSiVE]

so the smallest i can go without resistors would be 3 leds?

what about this if i use this
http://ledsupply.com/03023-d-n-500.php
500mA driver at 3w would pull 6volts and the minimum for that is 5 volts. would it work for 1 led?

That buckpuck will require a few things to work.

As it is only a constant-current driver, not a power supply, You're going to need a power supply for the voltage input lines, It's minimum voltage input is 5v, so if you can find a wall wart that is claimed as 5V, test it to be sure it is actually putting out 5v. Once you wire its inputs to the power supply at 5v, It'd still be smart to run a 2Watt 2 ohm resister in series with the LED, but you may not have to.. I just wouldnt expect the emitter to last the typical 50,000 hours.

to answer your initial question, if you use one of the widely used meanwell drivers, yes, the ideal lowest number of LEDs is 3.

[jolson10450]

That buckpuck will require a few things to work.

As it is only a constant-current driver, not a power supply, You're going to need a power supply for the voltage input lines, It's minimum voltage input is 5v, so if you can find a wall wart that is claimed as 5V, test it to be sure it is actually putting out 5v. Once you wire its inputs to the power supply at 5v, It'd still be smart to run a 2Watt 2 ohm resister in series with the LED, but you may not have to.. I just wouldnt expect the emitter to last the typical 50,000 hours.

to answer your initial question, if you use one of the widely used meanwell drivers, yes, the ideal lowest number of LEDs is 3.

alright. i may have a solution. i didnt even realize my boss ordered some cree LEDS from china that are already prebuilt with drivers and power supply built in. i got to check on the watt and spectrum but i might use that. or i might just say screw it since its only 1g and do just freshwater like it is built for and put like 6 neon tetras in it lol

[XSiVE]

alright. i may have a solution. i didnt even realize my boss ordered some cree LEDS from china that are already prebuilt with drivers and power supply built in. i got to check on the watt and spectrum but i might use that. or i might just say screw it since its only 1g and do just freshwater like it is built for and put like 6 neon tetras in it lol

Im sure your boss has the specific BIN number that you guys ordered for those, that should tell you everything you need to know.