BowieReefer84 January 12, 2011 January 12, 2011 Ok, here is the deal. I am currently driving 12 Cool White XP-G R5's on a Mean well LPC-60-1050. I want to swap some blues into the mix. Are there any CREE blue LED's available that can be driven on a Mean well LPC-60-1050? I am driving XR-E blues on a LPC-35-700W, but it is my understanding the LPC-60-1050 is to powerful to drive these same LED's. I want to replace like 4-5 of the white's with blues on the LPC-60-1050.... Let me know if you need any additional details of my setup to provide an accurate answer. THANKS in advance, Mike
Guest thefishman65 January 12, 2011 January 12, 2011 The XR-E are rated at 1 amp. The 1.050 amps. Will the extra kill the LED yes but how fast? It might take seconds or years I really don't know. The only thing todo is place a resistor in series to use some of the current. Assume the voltage across 1 LED is 3.3 volts. And you want to drop 100 ma leaving 950 for the LED. Since voltage equals resistance times current. R = 3.3 volts / .1 amp or 33 ohms. It will drop .1 * 3.3 or 0.33 watts so you probably want a 1/2 watt resistor. Now if the LED short or opens you may have problems.
BowieReefer84 January 12, 2011 Author January 12, 2011 (edited) In other words, I have to keep waiting for more powerful blue led's.... I am not trying to do anything more than swapping led's at this point. The color is not bad, I just want more blue. I wonder why they do not make XP-G R5's in blue? Edit - What is the deal with the XP-E blues? found here -> http://www.rapidled.com/servlet/the-124/CREE-XP-dsh-E-Royal-Blue/Detail Edited January 12, 2011 by BowieReefer84
TonyD January 12, 2011 January 12, 2011 You're not going to like this answer. XP-G R5 cool whites are rated at 1500 mA. The XP-E and XRE royal blue leds are rated at 1000mA. You will fry the XP-E and XR-E blue leds if you drive it with what you are currently using to make the Xp-G R5 leds work. 1) You will need to buy blue leds rated at 1500mA (doesn't exist that I've seen) or 2) Turn down your LPC-60-1050 driver so that it is only putting out 900 mA. That will make your blue leds work, but will also make your XP-G R5 cool white leds dim. How dim? I don't know. You'll have to turn it down now to 900mA on your current setup to see if it's acceptable to you. Putting a resistor in series will not use up some of the current from the driver. The current will still travel across the resistor and the leds with the same current. It will however cause a voltage drop at the resistor so less voltage will be available at the leds. If you want to divert some of the current away, you need a parallel circuit. But if you do that, you might as well tune down your driver and be done with it.
Guest thefishman65 January 12, 2011 January 12, 2011 XP-E have a wider spread then the XR-E but otherwise are about the same. Still 1 amp limit. The only thing besides a parallel resistor would be a new driver. Get an ELN and limit the current below 1 amp.
BowieReefer84 January 12, 2011 Author January 12, 2011 Thank you for the answers. I will wait to see if any new blue led's come out. I sent an email to Rapidled asking what they might be adding to the site in the future.... I am happy for now.
Guest thefishman65 January 12, 2011 January 12, 2011 XM-Ls will probably be added next. Brighter white. White are the driving force in the industry to replace CFLs IMHO.
ErikS January 12, 2011 January 12, 2011 thefishman65 will correct me but IIRC from the DIY thread the output from the LEDs isn't linear. I seem to recall some testing (der_wille???) that made mention the output difference between 750ma & 1000ma is minimal. I drive both the blue & XPGs at this level.........how much does it dim? Can't say as I have no hard data. Not noticable to the mark I eyeball............but we know that's meaningless
BowieReefer84 January 13, 2011 Author January 13, 2011 (edited) What are your guys opinion on the new "XP-G neutral white" Led's that CREE is about to release? More yellow or more blue than "cool white?" EDIT - I just saw they are more yellow. booo Also,.... thinking of what if's. Can I run say 6 blue xr-e's off the 35-700, and run 12 xp-g's AND the other 6 xre's off the 60-1050? I am just trying to think outside the box, and not have to purchase anything else.... Edited January 13, 2011 by BowieReefer84
Guest thefishman65 January 13, 2011 January 13, 2011 I need to know how you are thinking of wiring? Six on a LPC?-35-700 is half load IMHO. And I don't know how you would get 18 on a ELN?-60-1050?
BowieReefer84 January 13, 2011 Author January 13, 2011 I don't know... It is a miracle I completed this build in the first place lol. OK, what is the least amount of XP-G's I can drive on the lpc-60-1050? 24 LED's on my tank is a lot, maybe I can just take away some whites to make it bluer.... This would be the easiest solution probably, and it will still be plenty of light for sps I would think. Thanks for being so patient!
Guest thefishman65 January 13, 2011 January 13, 2011 In the data sheet the DC voltage range is 9 to 48 volts. So I would say 4. That would make the voltage 2.25 per LED. Maybe 3 that would be 3 volts per, but IIRC that is right on the edge of 1 amp for the XP-G. It sounds like you have 12 so I doubt you will go as low as 4.
BowieReefer84 January 13, 2011 Author January 13, 2011 In the data sheet the DC voltage range is 9 to 48 volts. So I would say 4. That would make the voltage 2.25 per LED. Maybe 3 that would be 3 volts per, but IIRC that is right on the edge of 1 amp for the XP-G. It sounds like you have 12 so I doubt you will go as low as 4. You are correct. Currently I have 12 whites, and 12 blues on seperate drivers. I will most certainly leave all 12 blues, but decrese the whites to say 8 from 12. This will provide enough par, and more blue. THANKS!!!!!
basser9 January 14, 2011 January 14, 2011 (edited) As long as you cool the Royal blues there is little difference to the led driven at 1000 or 1050ma.....either way you need to cool them with fans. just like if you overclock a computerchip[must cool it] there is a wide margin from what the manufactor rates something at and what you can run something at. 50ma extra is nothing to worry about. The difference in par from a RB DRIVEN AT 1000MA then 700 is more then you think as long as you cool it. I have had a par meter for 3 years and i cant imagine setting up reefs without one. Someone on rc ran one at 1500ma that alot but 50ma is nothing plus dont be to sure that driver is putting that amount out test it. The only time to worry about something like that is if a warranty is involved. Edited January 14, 2011 by basser9
BowieReefer84 January 14, 2011 Author January 14, 2011 As long as you cool the Royal blues there is little difference to the led driven at 1000 or 1050ma.....either way you need to cool them with fans. just like if you overclock a computerchip[must cool it] there is a wide margin from what the manufactor rates something at and what you can run something at. 50ma extra is nothing to worry about. The difference in par from a RB DRIVEN AT 1000MA then 700 is more then you think as long as you cool it. I have had a par meter for 3 years and i cant imagine setting up reefs without one. Someone on rc ran one at 1500ma that alot but 50ma is nothing plus dont be to sure that driver is putting that amount out test it. How do I test the driver for output? I have a multimeter....
Guest thefishman65 January 14, 2011 January 14, 2011 basser I read a fair amount on RC never read of anyone running a royal blue at 1500ma. Do you have a link? Just like you measured the current before. Measure the current of the combined string and see what it is running? You could also place two blues in parallel each would run about 500ma. If one ges the other will get the whole 1050, but hopefully it won't happen. There is a difference between over clocking and over driving the voltage. The changing state on each clock causes the chip to draw a lot of current to change state. This intern raises the temperature. If you try and clock it too fast it can't keep up. If you get it oo hot it may fail. Run that same processor at a higher voltage and all you get is fried processor for dinner.
basser9 January 15, 2011 January 15, 2011 (edited) 1 of the regulars on rc ran one at that to see what would happen. I ran some cheap chinese 1 watt blues at 2 watts and for 1 year they got hot but held up. Funny that until CREE went back and tested there RB at 1000ma there were some that ran them at that with no problem but people said you could not because CREE said you cant. ...That diy at its heart...Thats how we more forward....Trust me 50ma is very little extra for leds. But they may blow up .....run some see what happens Edited January 15, 2011 by basser9
hypertech January 15, 2011 January 15, 2011 The XR-E are rated at 1 amp. The 1.050 amps. Will the extra kill the LED yes but how fast? It might take seconds or years I really don't know. The only thing todo is place a resistor in series to use some of the current. Assume the voltage across 1 LED is 3.3 volts. And you want to drop 100 ma leaving 950 for the LED. Since voltage equals resistance times current. R = 3.3 volts / .1 amp or 33 ohms. It will drop .1 * 3.3 or 0.33 watts so you probably want a 1/2 watt resistor. Now if the LED short or opens you may have problems. A series resistor will not change the current through the LED.
Guest thefishman65 January 15, 2011 January 15, 2011 Your right I meant parallel. Either BowieReefer understood what i was tryng to say or he can rethink the project again
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