DIY LED - Group Buy

[jthunder]

I'm looking at ordering some LED's direct from a manufacturer from China. Here is the specs:

3w cool white led, with PCB, 220lm, 3.4-3.6V, 700mA , 18000-20000K , 120degree, Price is USD1.27/pc
3w royal blue led, 450-455nm with PCB, 120degree, 40-45lm, 3.4-3.6V, 700mA, Price is USD2.29/pc
60degree lenses for single 1w or 3w high power led. Price is 0.137/pc

Minimum order quantity on these items is 100x. If there is a couple of people interested we can get an order together. Send me a PM if interested.

Regards.

[sphelps]

I'd like to here some comments from some LED experts on whether these are compatible to CREE. I'm pretty sure XP-G are rated 493lum max and have flux = 139lum @ 350mA.

thunder, do you have a link to a spec sheet? I would be interested if they are somewhat comparable to crees. I would order over 100 LEDs myself at that price. Also do they have red and green?

[Ross]

[rstar]

would like to know how this goes as well...

[GMGQ]

Cree blues and whites max out at 1000ma and 1500ma respectively, but most people run them around 700ma.

If these china LEDs max out at 700ma, then you would probably want to run them at 500ma.

So they're not going to be as bright as Crees.

I think this is a case of you get what you pay for.

[Bryan]

You may want to look at the LEDS from Satistronics. the blues are very good, but not so sure about the whites as I have never tried them. Prices about the same and the shipping is fast.

http://www.satistronics.com/3w-high-...0lm_p1317.html

[jthunder]

Did you try these LEDs? what drivers/power supply did you use?

[Bryan]

I have used the 3w blue leds and they work well, but I don't have any Royal Blues to compare with, but there is some info on nano-reef's that the two are almost identical. I am using the Sure drivers, cheap and seem to work well, but do get quite warm when run at close to capacity.

the leds are on a nano reef so just using a 24v laptop powersupply. The sure drivers are quite forgiving for voltage and you have a wide range depending on number of LEDS used.

http://cgi.ebay.com/3w-LED-Driver-MB...item3a6442f9f3

[mason dixon]

Originally Posted by Bryan

I have used the 3w blue leds and they work well, but I don't have any Royal Blues to compare with, but there is some info on nano-reef's that the two are almost identical. I am using the Sure drivers, cheap and seem to work well, but do get quite warm when run at close to capacity.

the leds are on a nano reef so just using a 24v laptop powersupply. The sure drivers are quite forgiving for voltage and you have a wide range depending on number of LEDS used.

http://cgi.ebay.com/3w-LED-Driver-MB...item3a6442f9f3

I'm new to leds's....what is the advantage of running those small 3w drivers(I'm assuming one per led?) over something like this this?

[Bryan]

Well, they can run up to 8 LEDs on each driver. From the bottom of the Ebay page is a link to the datasheet, which describes the specs and voltage required for the amount of LEDS used. You will need to provide a PWM input for dimming. A simple 555 timer can take care of that.