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DIY LED - Group Buy
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. |
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? |
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would like to know how this goes as well...
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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. |
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 |
Did you try these LEDs? what drivers/power supply did you use?
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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 |
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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.
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Thanks, I was thinking that can't be right but I had to ask since I'm such a noob.
Will 1 24v laptop pwm be enough for 72 led's? |
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For 72 LEDs you'll need at least 200W which I believe is much more than the average laptop requires. You can buy other power supplies that run at 24V at much higher wattage than a laptop supply. I would go larger to the range of 300-350 W encase you ever wanted to add more LEDs. |
for a power supply you don't want to go by watts. while this can work it is much easier and safer to go with a constant curent output. so figure out what current you want to run at (700mA or 1000mA) then get one that has enough voltage to handle the amount of LEDs. you want to run your blues on a different power than your whites
here is an example of one of the better drivers to come out laitly http://www.nanotuners.com/product_in...roducts_id=754 this is a 64 top 114 volt driver at 1050mA you can get them bigger or smaller. Steve |
Steve are you talking about a power supply or driver? If the driver runs off 120VAC then obviously you don't need a power supply but some drivers already discussed require a lower voltage DC supply so you need a separate power supply. The driver must be constant current but the power supply only needs to have enough power (watts) to run the driver(s). The voltage of the supply is also important and dependent on how many LEDs are in each array for each driver.
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the units I was talking about will self adjust to a requirment between 64 and 114 volts. the TR are a little more cost wise than meanwell but they have the higher capacity ie. this one will handle about 33 LEDs (max), they dont have the inrush problem that the mean wells have. as well as they also have a built in 10V reference voltage so for manual dimming all that is required is a pot. heres a link to the info sheet on them http://www.thomasresearchproducts.co...2001-31-11.pdf Steve |
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think about what were doing here. we're soldering a ton of wires to pads on a hunk of aluminum and suspending it over a tank of water... what is safe about this in the first place? as with any DIY involving electricity, this is not for some one who doesn't feel confident working with electricity and there skills to do so. I am actually testing a couple ways to electrically isolate everything after it is together, for a few reasons. one - so humidity can condensate and make a water drop shorting out a led to the heat sink, two - so you don't bump a bare wire while your working by the light, and 3 - to prevent corrosion of the solder joints from salt creep and humidity. when I find one I am happy with I'll post it, but so far the liquid electrical tape is looking pretty good. Steve |
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As for a cleaner look I guess it depends on your design, but I think the AIOs are bulky and having a large number of them makes things the opposite of clean. Using a separate power supply means one power supply that can be installed virtually anywhere like under the stand or in an electrical compartment and the drivers are very low profile and can be as small as a couple square inches making them very east to build into your heat sink. I've also noticed a lot of the stand alone drivers offer both 0-10V and PWM control so if you're not sure which one you want to use the option will always be there without having to change out drivers down the road. The AIO have the advantage of simplicity and perhaps better suited for smaller builds only requiring one or two drivers. But for larger lighting systems which use many drivers for more levels of control I think the stand alone approach is the way to go. |
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the problem I have found with the stand alones are that they are all based on a 10V for PWN amd volatage, while this isn't a real problem it does involve building a new circut if you use any ardruno based setup, as they are only a 5V PWM signal, and if you want to build 0-10V you need to have a seperate wall wart and circut to supply the referance voltage. as for the cleaner look, if you use meanwells which are so 2010 :mrgreen: ya you will need one unit for every 13 LEDs so on a large build you will need more of them, which is the beauty of the newer TR drivers as you can get them in different sizes up to ones that will do between 25 (min) and 82(max) LEDs in series with one constant current driver so a very large build can have two drivers measuring 2" x 10" each which don't have to be in the fixture, but rather behind the stand or what ever. you have to remember for each little driver you put in the fixture you have to figure there heat output into the capability of the heat sink. take "steve's" drivers.. they are the cheepest I have found at 15 bucks each on sale that are a nice Driver ( will take ardruno input from the box and also 10V control) but they have to be mounted to a heat sink of some kind and disapate 6 watts for a single channel driver so on a large build that will add substantualy to the requirments of the heat sink. oh and they will only handle 6 or 7 LEDs per channel. Steve |
This is really old, but did these ever get ordered? I could go for about 30 of the blue if someone has spares or is interested in a split.
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Im guessing that they are not based in canada? The added cost would be worth it if so, but beyond that they are actually a bit overpriced compared to getting similar products abroad.
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Any of these supplies...
Can you get the following items:
http://reefledlights.com/shop/led-seal/ : this is a spray to protect the welds... by a company called Luxdrive. Philips LEDs - Rebel ES series.... apparently better than CREE in terms of lighting suitability for corals. nano-box-reef.com/ uses them. msjboy |
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Steve |
comparing to the $400 AI Sol which has 24 Cree LEDs, going with www.ledgroupbuy.com to build similar (mix of 24 XP-G and XP-E, couple of power supplies, heatsink, optics and connectors) would cost about $265.
This right? |
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