Introducing CobKits.com - specializing in DIY and Citizen COBs

GrowLightResearch

Well-Known Member
Yes. It is recommended to add a 10k resistor in series as many cheaper 100k pots are a little below 100k due to manufacturing tolerances. 100k or more is needed to get 100% power from a MW driver. http://cobkits.com/product/bourns-100k-potentiomenter/
Not really. Pot manufactures understand that if the "End Resistance" if off that will make the pot useless for many [projects. That is why pots have the "End Resistance" spec. While the pot may have a 12 or 20% tolerance the end resistance will be like a few ohms or 1%. End resistance refers to both the low and high end.

The problem with adding a 10K series resistor is you lose the bottom 10%.

There is a reason this pot is called a trimmer. Because a trimmer pot is used to trim the resistance of the parallel resistor.

But if you want to really do it correctly you'd use a variable 0-10v power source. That is what Mean Well recommends. Not that @CobKits cares about doing things correctly. That fabricate "safe zone" is not a real thing. Blind leasing the blind.

From LED Magazine

If you are aware of the current draw needed to match application light-level requirements, you'd probably choose a constant current array because it's usually the most efficient arrangement. If your LED array requires a constant current, then you'll need a CC LED driver. This type of driver will only have a certain range of voltages which it can drive; there will be a minimum voltage and a maximum voltage permissible. You need to ensure that your LED array has a voltage requirement that falls inside this permissible range.
 

CobKits

Well-Known Member
being wrong all the time isnt enough for you? you have to insult me too? get the fuck out of my thread nobody wants you here, your "contributions" are useless.

thanks for posting a description of a constant current driver and the fact that the cob array must fit between its min and max voltage range. truly groundbreaking stuff there. i have no idea what point you are even attempting to debate because i do not read 90% of your posts as I have you on ignore.

to clarify for people who you are attempting to confuse with your "logic":

-meanwell doesnt "recommend" 0-10V voltage over resistive voltage - it is by definition, a "3-in-1" dimming driver. there is no "correct" or "incorrect" method indicated by the manufacturer.

-almost all of the popular meanwells dont dim below 10% anyway, regardless of what type of dimming you use - easily verified by datasheet. you dont "lose" the bottom 10% as it doesnt dim below 10% whether you give it 1K ohm or 10K ohm

youve already demonstrated that unlike many hundreds of actual growers out there you dont understand how to safely use a low voltage power supply to wire LEDs in parallel - you are simply incapable of understanding how this can be accomplished despite everyone's best efforts to explain the very simple concept of matching a driver to a COBs voltage range.

in this thread youve also demonstrated you have no idea how drivers and chips work in regard to forward voltage

most recently, youve demonstrated the unsurprising feat of, while being able to regurgitate electronic jargon, you dont even know how to read and understand a driver datasheet. (We already know you cant read and understand a COB datasheet)

At the end of the day you are simply ill-equipped to advise others on any sort of project (in addition to simply being a know-it-all asshole almost all the time). Take your trolly bullshit and FUD elsewhere.
 

Cedru

Member
Wow, GLR! I'm with CobKits - your info is flawed at best, and to come into someone else's thread and saying that is rude, uncalled for, and just plain ignorant. Go into your own thread, discuss your way and ideas, and roll out of this one.

*.*.* Cedru *.*.*
 

Heisengrow

Well-Known Member
Hello.i have a question.im looking to fill in a 4x10 area x3 in the very near future.cost isn't a big deal.been reading your post and see you also sell the parts.i can put everything together just wondering what you would recommend for a 4x10 area.trying to keep it under 1200 watts per area.dont wanna go over 4000 watts total.
I was thinking 24 3590's and two of the 600 meanwell at 1400.
I have also been looking at the vero29s but can' get enough info to know what would be better
Any help is,appreciated.
 

HydroRed

Well-Known Member
Hello.i have a question.im looking to fill in a 4x10 area x3 in the very near future.cost isn't a big deal.been reading your post and see you also sell the parts.i can put everything together just wondering what you would recommend for a 4x10 area.trying to keep it under 1200 watts per area.dont wanna go over 4000 watts total.
I was thinking 24 3590's and two of the 600 meanwell at 1400.
I have also been looking at the vero29s but can' get enough info to know what would be better
Any help is,appreciated.
There are many here much better suited to offer advice on technicals, but the Cree 3590's are not far off from the Citizens (CLU048 1818's) which can be acquired for a fraction of the price. Basically you can get relatively the same bang for your buck, with less investment.
 

CobKits

Well-Known Member
3590s are pretty much obsolete until they start selling them for under $20

luminus cxm22 is a much better bet

they dont make 600W meanwells in constant current. you can run them at 1400 mA per cob but it will be in parallel
 

Heisengrow

Well-Known Member
3590s are pretty much obsolete until they start selling them for under $20

luminus cxm22 is a much better bet

they dont make 600W meanwells in constant current. you can run them at 1400 mA per cob but it will be in parallel
Yeah i really dont know anything about them just want the best for a 10x4 foot area.Im not trying to be on a budget.I would rather get what works so i dont have to upgrade later on down the road.ive also been looking at the Vero29's 24 per 10x4 paired with 4 of the 320 1400's.But again i dont know nothing cause because there is just so much information scattered all over the internet and searches seem to bring up old year old post.the technology is changing.So if you was me and money wasnt an issue(I will get it back in 1 grow)what would you go with to light up a 4x10 foot area and stay under 1300 watts or do i need more wattage?
 

CobKits

Well-Known Member
.the technology is changing
its really not changing that fast

any cob made in the last several years by major manufacturers such as cree, citizen, bridgelux/vero, luminus, etc will all grow top shelf crops and be more efficient than HID, as you can see by all the excellent journals over the last 3-4 years here

the difference... cost.

in the popular 40-70W range we like to use:

$19 luminus cxm22 gen 3
$23 vero29B gen7
$31 vero29C gen7
$24 citizen 1818 gen6
$32 cree cxb3590
$36 citizen 1825

are all gonna be +/- a few % in efficiency. there really is no "magic bullet" cob or spectrum that will make a significant difference in a side by side.

at the current time i think the luminus are the best deal going. literally as good as any chip out there in that range <70W

you could go as low as 21 cobs at 65W each in that space or as much as 40 cobs at 30W each. or anywhere in between. the 40 cobs at 30W (1200W) would put out about as much light as the 21 cobs at 65W (1365W). former would be about $1300 per 4x4, latter would be about $2500
 
Last edited:

Heisengrow

Well-Known Member
Will you be adding CO2:confused:

If not then 1300W is 32.5W/ft2 in a 4x10 space & most people are going with 30-40W/ft2 so u should be good :clap:
Just trying to keep my electric bill down.
I'm a shitty state.i run co2 but only atsmophere levels cause I'm in a sealed room.im in DWC so plants get out of control when I crank it up.
Any suggestions on drivers?i dont know nothing about this.i wanted to post in the other section but it' closed down cause people wanted to argue about hps vs led.found this one cause ol dude sells the stuff but he' giving me roundabout advice and oh u can use 20 or 40.I have no clue what that shit means.ill prob just ask in another section and find somewhere else to purchase.thanks for the helpful advice.
 

CobKits

Well-Known Member
Any suggestions on drivers?
meanwells are what 90% of people here use. they are the best.
he' giving me roundabout advice and oh u can use 20 or 40.I have no clue what that shit means.
well any LED becomes more efficient when run softer

basically lets take the cob i was recommending, the luminus cxm22.

most people would run those at a max of 75W each.

lets pretend you run them at 100W each, which is within their safe operating range. and that 100W cob over a given area gives you the exact amount of light your plants need.

if you replace that 100W cob with two of the same cobs run softer, they are more efficient so 2 cobs at 45W each (90W total) would give you the same amount of light

if instead you used 4 cobs to light up the same space, you could run them about 20W each and get the same amount of light as the two setups above and are now using only 80W

to put in in perspective, 1000W of light 12 hrs a day at 15 cents/kWh is about $600 a year.

(10) 100W cobs = $600/year
(20) 45W cobs = $540/year
(40) 20W cobs = $480/year

as a rule of thumb depending on how efficient you design your rig to be, you will need between 550 and 750W of LED to replace a 1000W HPS.

as i said above id put 21 cobs in that space if it was mine. bottom line is that if you know absolutely nothing about LEDs take a week to read and ask questions before you part with your hard earned money. you want a rig that fits your budget and does what you want it to do... but you need to understand it a little to make that decision. any of those rigs above are going to be 30+% more efficient than HPS, but when you start to add cobs you get to a point of diminishing returns. if you want to spend twice as much on the rigs to save 400W of heat between the three spaces (and the cooling cost/capacity to deal with it) and save $500 a year in electricity, thats your call. you will recover that money in about 5 years and be in the black year over year after that
 
Last edited:

ChaosHunter

Well-Known Member
Am I wrong in thinking 1 Cob per square foot ? Would rather drive more COB's softer than fewer harder for efficiency sake.
 

Heisengrow

Well-Known Member
meanwells are what 90% of people here use. they are the best.


well any LED becomes more efficient when run softer

basically lets take the cob i was recommending, the luminus cxm22.

most people would run those at a max of 75W each.

lets pretend you run them at 100W each, which is within their safe operating range. and that 100W cob over a given area gives you the exact amount of light your plants need.

if you replace that 100W cob with two of the same cobs run softer, they are more efficient so 2 cobs at 45W each (90W total) would give you the same amount of light

if instead you used 4 cobs to light up the same space, you could run them about 20W each and get the same amount of light as the two setups above and are now using only 80W

to put in in perspective, 1000W of light 12 hrs a day at 15 cents/kWh is about $600 a year.

(10) 100W cobs = $600/year
(20) 45W cobs = $540/year
(40) 20W cobs = $480/year

as a rule of thumb depending on how efficient you design your rig to be, you will need between 550 and 750W of LED to replace a 1000W HPS.

as i said above id put 21 cobs in that space if it was mine. bottom line is that if you know absolutely nothing about LEDs take a week to read and ask questions before you part with your hard earned money. you want a rig that fits your budget and does what you want it to do... but you need to understand it a little to make that decision. any of those rigs above are going to be 30+% more efficient than HPS, but when you start to add cobs you get to a point of diminishing returns. if you want to spend twice as much on the rigs to save 400W of heat between the three spaces (and the cooling cost/capacity to deal with it) and save $500 a year in electricity, thats your call. you will recover that money in about 5 years and be in the black year over year after that
So let' just say 24 cobs over a 4x8 can u recommend what drivers to run? Also do you sell the chips your talking about?also do you give discounts on bigger orders.I would need 72 cobs and whatever drivers and heat sinks to run them
 
Top