LED driver questions.....

weirdingway

weirdingway

Member
i decided to put this here rather than create what might be considered a redundant question in the LED section.

I just bought 2 full spectrum 100w COBs from ebay you can search under "100w full spectrum COB" and look for those from china costing around 16USD

and i have been trying to figure out what driver to use....so far im looking at this one so i can run the LEDs at full power.

(search ebay for "100w 36v 3a" led driver and you will see what im thinking about buying


my question is, is that "driver" all i need to power the LEDs or do i need a power supply also?


thanks for any help.
 
blake9999

blake9999

Well-Known Member
The driver IS the power supply

Try to give a little more about the COB's you bought such as voltage and manufacturer if that's known.
 
weirdingway

weirdingway

Member
blake9999 said:
The driver IS the power supply

Try to give a little more about the COB's you bought such as voltage and manufacturer if that's known.
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its rated at 30 to 36 volts. Its chinese made believed to have epileds.....

do you know how many of these i can run per driver at full power?
 
nfhiggs

nfhiggs

Well-Known Member
weirdingway said:
i decided to put this here rather than create what might be considered a redundant question in the LED section.

I just bought 2 full spectrum 100w COBs from ebay you can search under "100w full spectrum COB" and look for those from china costing around 16USD

and i have been trying to figure out what driver to use....so far im looking at this one so i can run the LEDs at full power.

(search ebay for "100w 36v 3a" led driver and you will see what im thinking about buying


my question is, is that "driver" all i need to power the LEDs or do i need a power supply also?


thanks for any help.
Click to expand...
Unfortunately, the cobs you bought are overpriced crap. For the 30+ dollars you paid for 2 of those, you could have gotten 3 Citizen CLU048-1212 gen 6 COB's with 160 L/W efficiency. Those "full spectrum" cobs are just "blurple lights" in a small package. What you want are true white light COBs in 3500K CCT (Warm white). Or if you want to go cheap you could get some of these:
http://www.ebay.com/itm/272510858745
I use these and they work pretty good. Not the efficiency of the Citizen, Bridgelux or Cree, but they are damned affordable.

BUT, you have what you have... So, to answer your question - forget about using "drivers", and just get a $25, 36VDC 11 Amp power supply:
http://www.ebay.com/itm/122360382360?
Then pick up one of these:
http://www.ebay.com/itm/172590142083?
Use that to set and monitor your COB current.

The power supply has a voltage adjustment, you just start with it at minimum and turn it slowly until your current is at about 2 amps per COB (I would not run them at 3 amps, for various reasons).
 
weirdingway

weirdingway

Member
thanks boss, thats some very useful info and those cobs for 3 USD? thats nuts! I might have to stock up on some of those.


so with the power brick you mentioned how many 100w cobs can i run off that one supply without substantial dimming? Ive read i need at least 20,000 lux at the canopy and some have said 100,000 lux during flower is optimal.....

i start flower next week hopefully so i still have some time to get some warm whites like you said but over here theyre a bit more expensive.....somewhere around 5-10 USD each and i think i need at least four in addition to the Two full spectrum i got.

what i really want is 1000 true watts so increase my yield to at least a pound....but this is my first grow of this size and lighting type so im pretty much in uncharted waters for me personally. Ive also done alot of training for the first time ever....topping multiple times and some LST bending and what not....nothing too fancy but just trying to keep a even canopy for the first time and increase yield per plant.

Thanks again for all your help!
 
weirdingway

weirdingway

Member
ok sorry another question....i really like the idea of an adjustable power supply.....wouldnt that mean i could add many COBs in parallel and just adjust the power up until they are almost maxed out?

also...i was looking at that power supply and i guess i dont understand where you adjust the output....is there a dial or dip switches or what?

thanks again for your great advice....im liking this transition from CFL to LED better the more i learn.
 
nfhiggs

nfhiggs

Well-Known Member
weirdingway said:
thanks boss, thats some very useful info and those cobs for 3 USD? thats nuts! I might have to stock up on some of those.


so with the power brick you mentioned how many 100w cobs can i run off that one supply without substantial dimming? Ive read i need at least 20,000 lux at the canopy and some have said 100,000 lux during flower is optimal.....

i start flower next week hopefully so i still have some time to get some warm whites like you said but over here theyre a bit more expensive.....somewhere around 5-10 USD each and i think i need at least four in addition to the Two full spectrum i got.

what i really want is 1000 true watts so increase my yield to at least a pound....but this is my first grow of this size and lighting type so im pretty much in uncharted waters for me personally. Ive also done alot of training for the first time ever....topping multiple times and some LST bending and what not....nothing too fancy but just trying to keep a even canopy for the first time and increase yield per plant.

Thanks again for all your help!
Click to expand...
If you buy 10 at a time the price drops to less than $2 a pop. I've purchased from this particular seller before (just ordered 10 more in fact) and he is pretty good. He sent me a replacement for one of mine no questions asked.

It will push as much as 400W total divided into however many COB's you want to use. Four COBs at potentially 100W each. The thing to keep in mind is that with COB's (and LED's in general) their efficiency drops the harder you drive them. So you will actually get more total light with 8 COBs at 50W each than you will with 4 COBs at 100W each. I generally suggest driving them at 50% of their rated power.

weirdingway said:
ok sorry another question....i really like the idea of an adjustable power supply.....wouldnt that mean i could add many COBs in parallel and just adjust the power up until they are almost maxed out?

also...i was looking at that power supply and i guess i dont understand where you adjust the output....is there a dial or dip switches or what?

thanks again for your great advice....im liking this transition from CFL to LED better the more i learn.
Click to expand...
If you look to the left of the power terminals you will notice a green power light and a little orange adjustment right next to it. You adjust it with a small flat screwdriver.
 
weirdingway

weirdingway

Member
nfhiggs said:
If you buy 10 at a time the price drops to less than $2 a pop. I've purchased from this particular seller before (just ordered 10 more in fact) and he is pretty good. He sent me a replacement for one of mine no questions asked.

It will push as much as 400W total divided into however many COB's you want to use. Four COBs at potentially 100W each. The thing to keep in mind is that with COB's (and LED's in general) their efficiency drops the harder you drive them. So you will actually get more total light with 8 COBs at 50W each than you will with 4 COBs at 100W each. I generally suggest driving them at 50% of their rated power.


If you look to the left of the power terminals you will notice a green power light and a little orange adjustment right next to it. You adjust it with a small flat screwdriver.
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sorry i thought of another question: why 3500K and not 2700K for flower? is it kind of a best of both worlds approach between 2700K and 6000K or something like that? would i be ahead to just get a few of each? Like you said, if i ran 8 COBS at half power and run 8 COBs per power supply i could run (4) 2700K and (4) 6000K on one PSU and on the other PSU run (6) 3500K and the (2) full spectrum ive already ordered. That would give me a total of 800 true watts or thereabouts?

If i wanted to run close to 1000 true watts what would a good strategy be using two PSUs and 16 COBs? or is there a better arrangement you could advise?

thanks again!
 
nfhiggs

nfhiggs

Well-Known Member
weirdingway said:
sorry i thought of another question: why 3500K and not 2700K for flower? is it kind of a best of both worlds approach between 2700K and 6000K or something like that? would i be ahead to just get a few of each? Like you said, if i ran 8 COBS at half power and run 8 COBs per power supply i could run (4) 2700K and (4) 6000K on one PSU and on the other PSU run (6) 3500K and the (2) full spectrum ive already ordered. That would give me a total of 800 true watts or thereabouts?

If i wanted to run close to 1000 true watts what would a good strategy be using two PSUs and 16 COBs? or is there a better arrangement you could advise?

thanks again!
Click to expand...
The lower the CCT, the less efficient the COB. A 3500K will generally put out more light than a 2700K at the same wattage.
 
nfhiggs

nfhiggs

Well-Known Member
weirdingway said:
sorry i thought of another question: why 3500K and not 2700K for flower? is it kind of a best of both worlds approach between 2700K and 6000K or something like that? would i be ahead to just get a few of each? Like you said, if i ran 8 COBS at half power and run 8 COBs per power supply i could run (4) 2700K and (4) 6000K on one PSU and on the other PSU run (6) 3500K and the (2) full spectrum ive already ordered. That would give me a total of 800 true watts or thereabouts?

If i wanted to run close to 1000 true watts what would a good strategy be using two PSUs and 16 COBs? or is there a better arrangement you could advise?

thanks again!
Click to expand...
Three of the 400W supplies each one pushing 6 lights at 50W per light gets you 900 true watts.
 
weirdingway

weirdingway

Member
awesome, now i have a direction to go. I am going to return the driver i ordered and get the PSU you suggested and a five pack of those citizen cobs to start with next next paycheck two weeks later ill get another PSU and 5 more cobs and run all of those until i get afford a 3rd PSU and bring over a few cobs to the arrangement you specified.

thanks alot man, do you have some grow journals on here? sounds like youve troubleshooted alot.
 
nfhiggs

nfhiggs

Well-Known Member
weirdingway said:
awesome, now i have a direction to go. I am going to return the driver i ordered and get the PSU you suggested and a five pack of those citizen cobs to start with next next paycheck two weeks later ill get another PSU and 5 more cobs and run all of those until i get afford a 3rd PSU and bring over a few cobs to the arrangement you specified.

thanks alot man, do you have some grow journals on here? sounds like youve troubleshooted alot.
Click to expand...
No journals, but you can see all my pics at imgur:

http://nfhiggs.imgur.com/
 
nfhiggs

nfhiggs

Well-Known Member
weirdingway said:
awesome, now i have a direction to go. I am going to return the driver i ordered and get the PSU you suggested and a five pack of those citizen cobs to start with next next paycheck two weeks later ill get another PSU and 5 more cobs and run all of those until i get afford a 3rd PSU and bring over a few cobs to the arrangement you specified.

thanks alot man, do you have some grow journals on here? sounds like youve troubleshooted alot.
Click to expand...
just remember each of those cobs will need to be attached to a heatsink.
 
weirdingway

weirdingway

Member
nfhiggs said:
just remember each of those cobs will need to be attached to a heatsink.
Click to expand...
yeah thats going to be an ongoing issue since i think i have only like 4 or 5 and theyre pretty expensive with fans.

speaking of heatsinks is there a way to attach LEDs without the heatsinks being tapped for screws and maybe just using some kind of thermal adhesive or something? Right now on ebay theres a guy unloading 8 giant heatsinks without fans and theres a chance i could get them super cheap (only one bid for 1 dollar right now, 4 days left).

How do LEDs do with passively cooled heatsinks and how big do they need to be? Could having ambient moving air around the heat sinks such as from a fan in the grow tent provide enough air movement to help the heatsinks cool down better?

PS whats wrong with the site that i cant unlock my full account by liking ppls posts? thats the only thing holding me back from being able to post links!
 
nfhiggs

nfhiggs

Well-Known Member
weirdingway said:
yeah thats going to be an ongoing issue since i think i have only like 4 or 5 and theyre pretty expensive with fans.

speaking of heatsinks is there a way to attach LEDs without the heatsinks being tapped for screws and maybe just using some kind of thermal adhesive or something? Right now on ebay theres a guy unloading 8 giant heatsinks without fans and theres a chance i could get them super cheap (only one bid for 1 dollar right now, 4 days left).

How do LEDs do with passively cooled heatsinks and how big do they need to be? Could having ambient moving air around the heat sinks such as from a fan in the grow tent provide enough air movement to help the heatsinks cool down better?

PS whats wrong with the site that i cant unlock my full account by liking ppls posts? thats the only thing holding me back from being able to post links!
Click to expand...
take a look at these:

http://www.ebay.com/itm/361536790279

I use them and they work pretty good. If the fan dies on it, you just pop it off and slap a new one on it. I keep a bunch of cheap fans of various sizes on hand.

Arctic Silver makes an epoxy Thermal Adhesive thats perfect for attaching cobs to heatsinks..
 
weirdingway

weirdingway

Member
nfhiggs said:
take a look at these:

http://www.ebay.com/itm/361536790279

I use them and they work pretty good. If the fan dies on it, you just pop it off and slap a new one on it. I keep a bunch of cheap fans of various sizes on hand.

Arctic Silver makes an epoxy Thermal Adhesive thats perfect for attaching cobs to heatsinks..
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what do you think about this one? Theres a guy selling a group of them and the bid right now is 1 dollar...

http://www.ebay.com/itm/DELL-HEAT-SINK-W-BRACKET-AND-2-SCREWS-FROM-0JC474-LGA775-SOCKET-MOTHERBOARD-/222455669390?hash=item33cb64228e:g:FZoAAOSwWxNY25AB
 
weirdingway

weirdingway

Member
nfhiggs said:
Those should work quite well. CPU heat sinks are perfect.
Click to expand...
so heres where im at so far.

i finished wiring up my mickeymouse job today......an led driver straight to the LEDs, two of them screwed to CPU heatsinks and fans i had from old junk PCs. I test fired it and measured temps at the LED and never went above 110F...which i guess is good...ill post pics later...its nothign to brag about but it works....i havent installed it in my grow space yet but i think it will do fine to replace the CFLs i was using and i think it will be alot cooler in there....

cant wait till i can order those citizen cobs you showed me...thats when my game gets taken to the next level.
 
nfhiggs

nfhiggs

Well-Known Member
weirdingway said:
so heres where im at so far.

i finished wiring up my mickeymouse job today......an led driver straight to the LEDs, two of them screwed to CPU heatsinks and fans i had from old junk PCs. I test fired it and measured temps at the LED and never went above 110F...which i guess is good...ill post pics later...its nothign to brag about but it works....i havent installed it in my grow space yet but i think it will do fine to replace the CFLs i was using and i think it will be alot cooler in there....

cant wait till i can order those citizen cobs you showed me...thats when my game gets taken to the next level.
Click to expand...
Excellent! I'm looking to get a slew of those Citizens if Oregon ever gets around to actually sending me my refund. I think the bastards are holding them as long as possible to get more interest from the money.
 
weirdingway

weirdingway

Member
nfhiggs said:
Excellent! I'm looking to get a slew of those Citizens if Oregon ever gets around to actually sending me my refund. I think the bastards are holding them as long as possible to get more interest from the money.
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since youre in Oregon do you know that guy who builds the Black Diamond lights? i forget his name but this is his site.

http://www.perfectsunled.com/

and yes...if those citizen cobs are as good as they look im almost afraid they will get too popular and hard to buy.......do you think theres any chance small light businesses will start snatching them up? thats what i would do if i was going to start a grow light company....
 
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