DiY LEDs - How to Power Them

Tazbud said:
DQ no: 5
hmmm, two cobs running off a driver.. no worries. So then I put a switch on one and instead of switching off it still glows :-? off but glowing! No drama like, but is that ok, glowing (in wondering)? Maybe the switch isn't good enuff...
Click to expand...
Switch is on the positive wire or negative?
Maybe try the other?
 
Managed to trace it to the switch with my meter :cool: Thanks for the suggestion smokey.

I was thinking not much went wrong with switches but it was somehow a dud, it didn't have a very positive click off.
Read about the cobs glowing somewhere here but it was the driver after switch off. I'm actually kinda happy that I worked it out. I know some are silly questions to the boffins but it's hard not being able to get reassurance, a good mate is a sparky but doesn't smoke & his brothers a narc!

I think i'll try a proper fan dimmer for the noisy fan circuit.
 
Lol' some of this gets a mention on the first page (thanks supra). Iv'e read too many threads. Still not entirely sure why you shouldn't switch drivers, especially multi-cob drivers on the DC side..?
 
DP, those drivers put out 1750mA, which is too high for the 3Watters. So you would need a separate driver, maybe 700mA. As far as heatsink, the 92mm Arctic 11 Plus can usually be found for $10 each and is great for COBs. HeatsinkUSA is another great option for heatsinks in a larger build.
 
SupraSPL, You should go into business with your knowledge. I don't know you, yet I would feel confident buying your stuff. Keep up the good progression!
 
hi, i'm looking at some drivers just now, but i'm not entirely sure about my options...
could anyone weigh in and tell me, if the following ones would work for my purposes:



i want to drive four XM-L2 per driver, at either 1400mA or 1750mA, with one of these
Meanwell LPC-35-1400
Meanwell PLM-40-1750




for the CXA3070 COBs i would like to have the option of changing the current, ideally to anywhere between 700mA and 1050mA (or even up to 1400mA)
it's either three CXA3070 per driver with one of these:
Meanwell HLG-120H-C1050
Meanwell HVGC-150-1050A (??, listed with the addition "high voltage")
Meanwell HLG-185H-C1400A


or driven as singles with this one:
Meanwell LCM-60


the range of current for the first three drivers is listed as 525-1050mA (HLG-120H-C1050), 630mA-1050mA (HVGC-150-1050A), 700-1400mA (HLG-185H-C1400A)
what confuses me: does that mean i can drive them at anywhere inbetween as well, or can i just select either one of those two values??

the last one (LCM-60) garnered my interest, because it could seemingly drive the leds at anywhere from 500A to 1400mA (500/600/700/900/1050/1400mA with DPI), and compared to the other drivers the dimming options are all specified in the data sheet!
am i missing something?


thanks
 

Attachments

I would like to power two Vero 18 off one 32-34v 1750ma Driver. I know i will need resistors inline of each COB. I have looked through some books and came up with this. I would like to see each 18 at 700ma-850ma. Resistor needed=Voltage Supply - Vf of LED/Total of desired supply. 34v-29.5v=4.5/1.5 ma= 3.
I will need to put two 3k resistors inline of each COB. Ok i will need some input from the Masters if this is anywhere close.

The other noob question I have is why use resistors at all. The COB has the ability to run the the full power of the Driver. So if one COB goes down the other will just run the extra 700ma-850, as long as the cooling is already in place the extra current would not be a problem.

I would like to throw a huge thank you to all the LED GURUs that make this Forum Awesome!!!!!
 
I have a question for someone maybe epic or church or anyone really who knows.

Im finally building a veg light and just waiting on the LEDs should be only a couple more days they made it to the US yesterday from China.

MW HLG-60H-42B (dimmable, 42v @ 1.45A max)
14pcs. 4200-4500k XML2

vF max is 42 on the driver so may be able to run 14 XML2 which would be great, if not 13 or even 12 will be fine. I got a 100k ohm potentiometer/switch (it clicks off when turned all the way down). Do I need a resistor as well in series with the pot. for setting the minimum current, something like a 10k ohm resistor? If so what wattage rating on that resistor? Which pins on the pot. do I hook the positive and negative dimming wires from driver to?

I have some fresh seeds just sprouted today and I want to get the veg leds cranking the same day I get the XML2s in the mail so Id like to know if I need to source a resistor or not and also like I said which pins to hook pos/neg dimming circuit to.
 
Bueno Time said:
I have a question
... I got a 100k ohm potentiometer/switch (it clicks off when turned all the way down). Do I need a resistor as well in series with the pot. for setting the minimum current, something like a 10k ohm resistor? If so what wattage rating on that resistor? Which pins on the pot. do I hook the positive and negative dimming wires from driver to?

I have some fresh seeds just sprouted today and I want to get the veg leds cranking the same day I get the XML2s in the mail so Id like to know if I need to source a resistor or not and also like I said which pins to hook pos/neg dimming circuit to.
Click to expand...


https://www.rollitup.org/t/looking-for-a-driver.840201/#post-10762717
https://www.rollitup.org/t/what-drivers-i-need-for-2-vero-29.829566/page-2#post-10545847
 
benelux said:
hi, i'm looking at some drivers just now, but i'm not entirely sure about my options...
could anyone weigh in and tell me, if the following ones would work for my purposes:



i want to drive four XM-L2 per driver, at either 1400mA or 1750mA, with one of these
Meanwell LPC-35-1400
Meanwell PLM-40-1750

for the CXA3070 COBs i would like to have the option of changing the current, ideally to anywhere between 700mA and 1050mA (or even up to 1400mA)
it's either three CXA3070 per driver with one of these:
Meanwell HLG-120H-C1050
Meanwell HVGC-150-1050A (??, listed with the addition "high voltage")
Meanwell HLG-185H-C1400A

the range of current for the first three drivers is listed as 525-1050mA (HLG-120H-C1050), 630mA-1050mA (HVGC-150-1050A), 700-1400mA (HLG-185H-C1400A)
what confuses me: does that mean i can drive them at anywhere inbetween as well, or can i just select either one of those two values??

the last one (LCM-60) garnered my interest, because it could seemingly drive the leds at anywhere from 500A to 1400mA (500/600/700/900/1050/1400mA with DPI), and compared to the other drivers the dimming options are all specified in the data sheet!
am i missing something?
thanks
Click to expand...
IMO don't use the PLM 40. Lousy efficiency and your right on the edge with the 12 volts for 4 XM-L2s, use at least 5 XM-L2s with that one but again not one of MeanWells better drivers.

I'm 99% sure you can adjust the first 3 anywhere between it's stated current (potentiometer) but how fine is it? Ask MeanWell or these guys to be sure.
http://www.trcelectronics.com/Meanwell/power-supply-led.shtml

maddmattmurdock said:
I would like to power two Vero 18 off one 32-34v 1750ma Driver. I know i will need resistors inline of each COB. I have looked through some books and came up with this. I would like to see each 18 at 700ma-850ma. Resistor needed=Voltage Supply - Vf of LED/Total of desired supply. 34v-29.5v=4.5/1.5 ma= 3.
I will need to put two 3k resistors inline of each COB. Ok i will need some input from the Masters if this is anywhere close.

The other noob question I have is why use resistors at all. The COB has the ability to run the the full power of the Driver. So if one COB goes down the other will just run the extra 700ma-850, as long as the cooling is already in place the extra current would not be a problem.

I would like to throw a huge thank you to all the LED GURUs that make this Forum Awesome!!!!!
Click to expand...

OK I'm a little fuzzy with what you're doing. Are you trying to run the COBs in constant voltage mode? Is the driver a constant voltage driver? If not the driver you want to use doesn't have enough voltage for 2 Vero 18s. Also you don't need resistors. And no the COB will not handle extra currently that easily. If you really want to use that driver you'll need a boost driver wired in there. Actually I've read your question like 5 times and I get more screwed up the more I read it. Sorry.

Do you want to run them in series or parallel? Constant voltage or constant current? And what brand is the driver? What model? I sense your a little confused here but maybe I'm just really high.
 
guod said:
https://www.rollitup.org/t/looking-for-a-driver.840201/#post-10762717
https://www.rollitup.org/t/what-drivers-i-need-for-2-vero-29.829566/page-2#post-10545847
Click to expand...

Thank you, 100k ohm pot + 10k ohm resistor 1/4w+ will be fine.

I have 2 of these pots, it says 100k ohm on the webpage but one only reads up to 82.6k ohms with my multimeter, is that no bueno? The other one measures 91.1k ohms max.

https://www.futurlec.com/Potentiometers/POT100KBSWITCHpr.shtml

The part number on it is B104.

Im going to try the 91.1k with a 10k resistor.
 
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FranJan said:
IMO don't use the PLM 40. Lousy efficiency and your right on the edge with the 12 volts for 4 XM-L2s, use at least 5 XM-L2s with that one but again not one of MeanWells better drivers.

I'm 99% sure you can adjust the first 3 anywhere between it's stated current (potentiometer) but how fine is it? Ask MeanWell or these guys to be sure.
http://www.trcelectronics.com/Meanwell/power-supply-led.shtml



OK I'm a little fuzzy with what you're doing. Are you trying to run the COBs in constant voltage mode? Is the driver a constant voltage driver? If not the driver you want to use doesn't have enough voltage for 2 Vero 18s. Also you don't need resistors. And no the COB will not handle extra currently that easily. If you really want to use that driver you'll need a boost driver wired in there. Actually I've read your question like 5 times and I get more screwed up the more I read it. Sorry.

Do you want to run them in series or parallel? Constant voltage or constant current? And what brand is the driver? What model? I sense your a little confused here but maybe I'm just really high.
Click to expand...


Sorry Im a Noob at this. I was really into some Colorado Grape Ape 2012 when I asked the question. The driver is constant current driver.
Driving power: 50w
Model: 10 series 5 in parallel
Input Voltage: 85V~265V
Output Voltage: 32-34V
Current:1750mA
Efficiency > 88%
Power Factor >0.98
Operating Temperature: -20~80
Size (L * W * H): 110mm * 32mm * 23 mm
It is a cheap o EBAY.

I wanted to run two of them in parallel. I was under the impression in series it would stack the voltage and in parallel it stacks the current. I thought running them in parallel with a 3k resistor one each lead to the Vero. The R=V1-V2/I. R= resistor needed=V1(power supply voltage) 34-V2(forward voltage of Vero 18)29.5 I(total of current). 34-29.5=4.5/1500ma or 1.5= 3k resistor.
Less heat from each COB and one driver to two COBs and being able to run both at high amps and lower around 750ma to 800ma.

So that is what i was thunking.
 
maddmattmurdock said:
Sorry Im a Noob at this. I was really into some Colorado Grape Ape 2012 when I asked the question. The driver is constant current driver.
Driving power: 50w
Model: 10 series 5 in parallel
Input Voltage: 85V~265V
Output Voltage: 32-34V
Current:1750mA
Efficiency > 88%
Power Factor >0.98
Operating Temperature: -20~80
Size (L * W * H): 110mm * 32mm * 23 mm
It is a cheap o EBAY.

I wanted to run two of them in parallel. I was under the impression in series it would stack the voltage and in parallel it stacks the current. I thought running them in parallel with a 3k resistor one each lead to the Vero. The R=V1-V2/I. R= resistor needed=V1(power supply voltage) 34-V2(forward voltage of Vero 18)29.5 I(total of current). 34-29.5=4.5/1500ma or 1.5= 3k resistor.
Less heat from each COB and one driver to two COBs and being able to run both at high amps and lower around 750ma to 800ma.

So that is what i was thunking.
Click to expand...

Thank you for your help and passing on knowledge.
 
O
FranJan said:
http://www.bridgelux.com/wp-content...ro-Series-Electrical-Drive-Considerations.pdf

View attachment 3258197
Have you read this pdf? I know picograv runs his Vero 29s in parallel and maybe what you want to do can be done but why bother when you can just get drivers that are better suited. IDK maybe I'm getting old :).[/

Thank you, I have read the part were it is a bad idea due to hogging and runaways from diffences in vf of the Cobs. I see alot of Members refer to Mr Flux and his parallel string of cobs. I have looked high not low yet for the thread and have not found it. I think my thinking is off. That the resistor has to match the diffence of the vf of the high of the two. Then It cant run,hog or become V Obese.

The other option is pontentiometer.

Age always reminds of What my father would say "Pay attention and your old age will bring you wisdom" I know he borrowed that little gem from some were.
Click to expand...
 
Bueno Time said:
Thank you, 100k ohm pot + 10k ohm resistor 1/4w+ will be fine.

I have 2 of these pots, it says 100k ohm on the webpage but one only reads up to 82.6k ohms with my multimeter, is that no bueno? The other one measures 91.1k ohms max.
Click to expand...


welcome to the real world
:roll:


POTENTIOMETER, 0.4W LIN 220K
Adjustment Type: Screwdriver Slot
No. of Gangs: 1
No. of Turns: 1
Potentiometer Mounting: Panel
Power Rating: 400mW
Resistance Tolerance: ± 20%
Shaft Diameter: 6.35mm
Shaft Length - Metric: 50mm
Track Resistance: 100kohm
Track Taper: Linear

5% $olerance
http://cpc.farnell.com/bourns/3540s-1-104l/potentiometer-100k/dp/RE06829
 
FranJan said:
But ultimately won't it kill your efficiency even more? IDK maybe these folks can help ya, I'm out of my comfort zone here. Good Luck!
Pico
https://www.rollitup.org/t/bridgelux-vero-29-led-test.702193/
Mr Flux
https://www.rollitup.org/t/step-into-my-grow-room.801190/
Answers here???
https://www.rollitup.org/t/vero-29-questions.840891/#post-10790125
Click to expand...
In the driver or COB? I would think the driver would be the same, but i do believe you are correct in the loss of efficiency on the Vero 18, but that will be regained in HVAC savings.
 
maddmattmurdock said:
I wanted to run two of them in parallel. I was under the impression in series it would stack the voltage and in parallel it stacks the current. I thought running them in parallel with a 3k resistor one each lead to the Vero. The R=V1-V2/I. R= resistor needed=V1(power supply voltage) 34-V2(forward voltage of Vero 18)29.5 I(total of current). 34-29.5=4.5/1500ma or 1.5= 3k resistor.
Less heat from each COB and one driver to two COBs and being able to run both at high amps and lower around 750ma to 800ma.

So that is what i was thunking.
Click to expand...

this will work...and get the right resistor... the loss here is about 1 Watt...example in the pic
 

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