LED Group buy!

[QLe]

Resistor across dimming circuit.

QLE - what would the 1/2 ohm resistor do? I lost another 1 today - that makes 3 failures out of 6. It definitely wasn't heat - they were warm but were in an area that the heat could be dissipated (away from the LEDs). This one had been on 12 hours a day for 3 months. I'm running 18 LEDs in series on each of my drivers. Did we get a bad lot? I count at least 5 failures out of what, 17?

I think it has to do with the internal circuit to the driver. Remembering back to my electrical classes, you have to add a resistor across an led to reduce its current draw, it works without it one, but then the current draw is too much and burn up eventually. Likewise, with this driver. I just had another driver died on me this last weekend. Three had a resistor across it, one didn't (I was trying to run 100%). The one without the resistor died. Luckily, I had one more spare. So I added a 1 ohm resistor across this one as well.

If you have a rheostat or a potentiometer to drive the drivers, that's will be fine; but if you don't like myself, then you need a resistor.

Sorry for the late reply, for some reason, I don't get forum update email anymore when someone reply to this thread. I'll have to check my setting.

 

[saltySamurai]

QLE - thanks for the info. how many LEDs are you on each driver?

 

[QLe]

18 LED per driver.

 

[QLe]

Alright. I am now officially ****ed off. Another Chinese LED driver has died. This is my third one that died. I can officially say. Do not buy these drivers. This is crap! It's been operating normally until yesterday. It just never comes on anymore. I have a fan running to cool all of my drivers and it operate at room temperature away from water. So whatever is wrong, it is within the driver. I will now have to look for a better driver. Any recommendation anyone?

 

[randomfish]

sorry about your luck but thats why i bought evos from reefkoi

 

[lpsouth1978@msn.com]

Alright. I am now officially ****ed off. Another Chinese LED driver has died. This is my third one that died. I can officially say. Do not buy these drivers. This is crap! It's been operating normally until yesterday. It just never comes on anymore. I have a fan running to cool all of my drivers and it operate at room temperature away from water. So whatever is wrong, it is within the driver. I will now have to look for a better driver. Any recommendation anyone?

You can get BuckPucks from LEDsupply.com, they run 6 3w LED's each, or you can use meanwell drivers from RapidLED.com, I think you can run something like 13 LED's on one meanwell.

I have not used the meanwell drivers, but MANY others do. I have always used the buckpucks and have had NO trouble with them. I like the buckpucks because they are so small, only 1 inch square. I suggest getting the dimmable buckpucks if you go that route.

 

[Mckibbonator]

I like meanwells. They are a bit expensive, but work great.

 

[KhensuRa]

That sucks about them cheap arse drivers. i have been using a buck puck for a month now and so far so good. The only thing I am going to upgrade soon are the LED's, as I got the knock off China LED. I have seen the cheapys and the cree's working right next to each other and man what a Huge difference.

 

[QLe]

Alright, I ordered some Meanwell (eln-60-48d) from a local vender here Denver should be here tomorrow. It is rated for 1.3A, so Since I have 18 LEDs, i'm going to split into two parallel which would be about ~650mA per string of 9, which will work for these cheap leds from china.

@KhensuRa, I think i will upgrade to better led in a year or two too. By then hopefully, the XM-L led price will go down.

 

[saltySamurai]

out of the 7 drivers from the group buy, 5 died after 4? months. I switched out to Meanwell LPC-35-700 drivers. This means I went from 18 per string to 12 per string - therefore 6 Chinese drivers to 9 Meanwell. They've been up for a month - am very happy with them - no problems, working exactly as expected. Turns out I don't need them to be dimmable - I can adjust amount and blue / white intensity by just turning off the different strings. With 9 drivers hitting 108 LEDs, I can hit the mix that I want.

 

[asn-naso]

BTW - RapidLED told me that the Meanwell's can do 14 3 watt CREE's per string.

 

[QLe]

I wired my led's up to the meanwell last night, and all I can say is WOW! It made a big difference. The LEDs are actually brighter on meanwell driver than the Chinese driver. Because the eln-60-48d is rated for 1.3A, I split my 18 LED into two parallel strings of 9 each. I wired it in a mesh per the manufacturer recommendation (http://www.cdiweb.com/datasheets/meanwell/ELN-60-spec.pdf). I put a 9V (90%, 10V is 100%) battery up to the control line. I measured the current from the driver and it was 1.25A, the forward voltage of each LED was 3.6V. I didn't measure the current through each LED because I was too lazy to un-solder my solder. However, assuming perfect condition for parallel, the current should be 625mA. These Chinese LED are rated at 700mA, so I think this will work perfectly.

 

[Cake_Boss]

Just wondering if anyone has heard of this brand, http://www.excelsys.com/products/shelf_power.html?gclid=CKX02prY7qwCFUhgTAod0UAq5g

Sent from my DROIDX using Tapatalk

 

[Crit21]

I stumbled on this one today. It's a 50W white and blue LED. 2.8 Amps, 24-27VDC. It would need a serious heat sink, but it's less of a PITA than mounting a bunch of whites and blues.