LEDgardener

Ok I'm completely green at this diy stuff so I'm suddenly finding myself learning about electricity. I think the term is slowly slowly catchy monkey. I'm thinking of a two cob light fitting for a small veg cupboard. Achieving 250w hps equivalent. First step as far as I can ascertain, is to decide cob. My first question would be how do I determine the actual cob hardware? I'm looking at 4000k for vegging and I'm guessing at about 75w per cob. As far as I can tell the cob numbers dont reveal the most efficient wattage. So I suppose I'm asking how do I determine this from the manufacturers data sheets? Help greatly appreciated

I never understood half of the charts but remembering what growmau5 always said... the Cree run more efficient running them softer.. Vero and cities normally more efficient pushing them a little bit. basically if you want to run a chip under 50 watts use a Cree. over 50 use a Vero. luminous I don't know about...

you can always play around with Ledgardener's driver calculator on the blog page... you can look at all the chips (and quantum boards in the constant current calculator) at different amperage... I looked at the Vero 29b at 1400ma.. it's pretty much what you were thinking.. 2 chips 70 (over75) watts each for a 140w.. it even fits on a HLG 120h-c1400 running as close to the voltage max gives you the best efficiency.. I always though you wanted extra room to be more efficient. but I learned better here

this monkey has gone thru the confusion ( tho still a monkey)
based on cobkits test results if you are going to run them soft < 40 watts each then citi 1212 is hard to beat for the price, you wont gain much efficiency with the crees
if you are gonna run them hard> 70 watts then vero 29 72 volt version, then comes cxm22 then the vero 29 36 and 52 volts version....cxm 22 for the win if you are price conscious

since you want to run them for veg in a cupboard, you are not looking for high penetration so lights can/will be close in that case there is no point running a single cob @ 70 watts...you will have issues with heat and spread in a confined space.

I initially came to this board tryng to figure which cobs to run for the most efficient setup...ended up going with samsung lm561c boards so definitely look into that

Thankyou both for your input. You know, sometimes you just gotta take a hint! Both pointing firmly at quantum boards and my cob(b)led preconceptions (see what happened there?) offering resistance :/
Well it just seems that resistance is all but vanquished by its observation and monkey heart is now singing a quantum song, sung by sam and his 561 light orchestra
Thanks fellas.
Today I learned that vxa=w so now I can work out the wattage of electrical things, not bad for a small brained monkey eh! How interesting and so much fun this is, such an educational tree! Hang loose