the last led i had blew out it had 9 chips and only 3 would turn on thats why i think it needs a driver or something

You need a current limiter.

1. If you intend to always use the led from the power supply then all you need is a resistor. You have plenty of power so there is no reason not to use it. As someone above said maybe not the best choice but it is the most simple.

2. If you intend to eventually power the led from a battery then you will want to use a driver as they are more efficient.


But led drivers are not usually found on PCs.

 

It definitely needs a driver. It is my understanding that all high power LEDs need drivers. I've been working with high power LEDs for the past year due to a project of mine, and the simplest method I've come across to drive a high power LED is to use an LM317 as a constant current source. Do you know the voltage and current ratings of the LED? If the current is below 1.5 A, (which I suspect, since your LEDs sound like they're from LEDEngin and I've seen such LEDs there) you can use this circuit.

I highly doubt you'll find a ready made solution inside an old computer. If you want a reliable driver, you'll need to buy one or use a circuit like the one I've linked you to.

i like your method.. so i need an lm317 and a sense resistor what is that ? like a regular resistor ? and what is that on the right clip that says vf+3v ?

 

i like your method.. so i need an lm317 and a sense resistor what is that ? like a regular resistor ? and what is that on the right clip that says vf+3v ?

its really not a good method for "high power" leds as its a "linear" solution and will waste energy as heat to do its job..
No point IMO in using "green" lighting solutions like LED's then driving them with a linear source.

A meanwell LDD and 12V supply is a much better method IMO and requires less work/soldering and will be cheaper. The LDD drivers are like $5 and can be used with any 12V power supply with an output current greater than your requirements.

but for your learning..
sense resistor is just a regular resistor.. make darn sure its wattage is 2x or more calculated wattage..

Vf+3V is the supply voltage thats required.. Thats 3V more than the max Vf (forward voltage rating) of your LED..

make darn sure you put a heatsink on that LM317..

http://users.telenet.be/davshomepage/current-source.htm

 

its really not a good method for "high power" leds as its a "linear" solution and will waste energy as heat to do its job..
No point IMO in using "green" lighting solutions like LED's then driving them with a linear source.

A meanwell LDD and 12V supply is a much better method IMO and requires less work/soldering and will be cheaper. The LDD drivers are like $5 and can be used with any 12V power supply with an output current greater than your requirements.

but for your learning..
sense resistor is just a regular resistor.. make darn sure its wattage is 2x or more calculated wattage..

Vf+3V is the supply voltage thats required.. Thats 3V more than the max Vf (forward voltage rating) of your LED..

make darn sure you put a heatsink on that LM317..

http://users.telenet.be/davshomepage/current-source.htm

also the meanwell sounds good. can i hook more than 1 10 watt led up to this ? http://www.ebay.com/itm/1pcs-meanwe...473?pt=LH_DefaultDomain_0&hash=item4d196f0ae1

 

here.... $5 and its complete. free shipping too

http://www.ebay.ca/itm/221319884864...eName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

 

also the meanwell sounds good. can i hook more than 1 10 watt led up to this ? http://www.ebay.com/itm/1pcs-meanwe...473?pt=LH_DefaultDomain_0&hash=item4d196f0ae1

They can do up to 52V power supply..so
example..
if the 10W LED has a vf of 9-12V
then you can attach up to 4 x 10W LEDs to it..
BUT your power supply voltage must be 2V greater than the sum of the max vf for all leds in the series string..
So with 4 you would need a 12 x 4 = 48 +2 = 50V power supply.. (48V should work too assuming the vf stays at 11V or less..which is very likely)

and you can buy a version with wires instead of pcb pins to make it easier to work with..
AND if you want to be able to dim them you can use a 5V PWM signal for dimming.

 

if you buy the version I posted above, don't do what I did and buy a larger driver than you need. They are constant current and will overpower/kill your led if you don't use the correct wattage.

 

if you buy the version I posted above, don't do what I did and buy a larger driver than you need. They are constant current and will overpower/kill your led if you don't use the correct wattage.

yeah and don't go out and buy a non-dimmable one when you want dimmable either

So many people just don't know how LED's work.. They assume its just like a lightbulb..

If he wants the ability to attach 1 or 2 or 3,etc.. then the fixed Chinese junk you linked to won't work either..

 

man this is getting confusing. im just gonna go with t5 lighting

 

man this is getting confusing. im just gonna go with t5 lighting

saltwater reef tank lighting???

 

yesssir great guess

 

i was looking into the kessils but those things are like 300+ dollars im trying to make one myself lol for way cheaper

 

i was looking into the kessils but those things are like 300+ dollars im trying to make one myself lol for way cheaper

Check out oceanrevive.. ($175 shipped)
http://www.oceanrevivellc.com/goods.php?id=18
I've got a few of their S026 fixtures and they are GREAT... Run really cool..great adjustability.. GREAT coral growth even with SPS,etc..
I run 2 over my 120G long (72"L) currently.. I run them about 10" above the water level and run the "white" channel at 75% and blues at 50%.. but I don't like that "windex" blue look that many reefers do.. The added spectrum from the few red/green/UV is great for showing true colors..

I've also built a few DIY LED fixtures myself and you'd be hard pressed to build a comparable fixture for that price..

Haven't seen a single real complaint about them yet..

Kessils are just over hyped/over priced but when they came out the market would support that with just a few other $$$$ fixtures.. AI/etc...

Also check out the oceanrevive T247 if you want some more "automated" timer/dimming functions out of it

 

yeah and don't go out and buy a non-dimmable one when you want dimmable either

So many people just don't know how LED's work.. They assume its just like a lightbulb..

If he wants the ability to attach 1 or 2 or 3,etc.. then the fixed Chinese junk you linked to won't work either..

I just picked up some parts to test out the circuit that was posted in my thread. I might get to messing with it a bit today but it didn't cost much more and will achieve the result.

But back on track, why couldn't one use a 100W driver and run two 50W LEDs?

I agree, if you're speaking about expansion down the road and adding another 50W LED to a driver already running 2 50W LEDs on a 150W driver.

But if it's a known value with no plans for expanding then I don't see any reason why you can't string them together with my cheap Chinese crap (my words)

 

its a 10 watt led