1. We are currently experiencing issues with viewing and uploading images, our team is working on the issue.
    Dismiss Notice

Cheap and Cheerful DIY using Citizen cobs

Discussion in 'LED and other Lighting' started by JorgeGonzales, May 17, 2016.

  1.  
    Metacanna

    Metacanna Well-Known Member

    In US northerngrowlights.com is selling the 120mm at 14.5$, I would buy for that price... In Europe, so far the best I found is 111mm pin fin for 25€ ~ 26$. The Alpine 11 GT (80mm) costs 7.5$ here on the local store. I will give it another day to see if there are some deals outhere I might be missing.
     
  2.  
    CobKits

    CobKits Well-Known Member Rollitup Advertiser

    i posted the lm data on here a few weeks ago. like most cobs they are rated in the tens of thousands of hours

     
  3.  
    Metacanna

    Metacanna Well-Known Member

    Sorry I didn't get what you are saying. What is lm data and in what aspect are the cobs rated in the tens of thousands of hours? You mean, running at 140C?
     
  4.  
    CobKits

    CobKits Well-Known Member Rollitup Advertiser

    lm= lumen maintenance data. LM90= 90% of original lumen intensity

    yes they tested them at 105C case temp at 4600 mA which would put Tj around 140C. after 15000 hrs their estimates were

    LM90 = 36000 hrs
    LM80 > 90000 hrs
    LM70 > 90000 hrs

    at 55C case temp (and the same ridiculously high current), LM90 was 48000 hrs (12 years of 12/12)

    so it would be reasonable to expect an LM90 close to 60000-80000 hrs/15-20 years at the 1000-2000 mA most people run them at
     
    Big smo and Metacanna like this.
  5.  
    CobKits

    CobKits Well-Known Member Rollitup Advertiser

    also worth noting that due to the nature of the long test (15000 hrs so far), the ones they are currently testing are at least 2 gens old, maybe 3. they apply this data to the whole series but i gotta think the newer chips with better thermal properties would prob offer an advantage in lumen maintenance, but we wont know for another year or two (assuming they are even running tests with current chips)
     
  6.  
    DankaDank

    DankaDank Well-Known Member

    I think they have been running the CLU056.
     
  7.  
    Redoctober

    Redoctober Well-Known Member

    @CobKits Hey, just wondering if you're going to carry the new Gen 6 Citizen CLU048 - 1818 (90CRI) in 3500K?
    I see both the 4000K and the 3000K versions (in both 80CRI and 90CRI) but not the 3500K?
    Just curious
    Thanks
     
  8.  
    CobKits

    CobKits Well-Known Member Rollitup Advertiser

  9.  
    Metacanna

    Metacanna Well-Known Member

    I thought they would fry in seconds running at 4600mA. Are you referring to the 048-1212?

    So based in that information I conclude is ridiculous the amount of stress and caution people put in case of fan failure or overheat when building the lights. This things are much more reliable the I thought.

    When it comes to lumen maintenance, more likely the cobs we have will be obsolete in 2 or 3 years, plus, the cost will keep going down. The 1212 is selling for 10$, 3 years ago it's equivalent was selling at 40$? My point is, we will be replacing them faster than they start degrading.
     
  10.  
    CobKits

    CobKits Well-Known Member Rollitup Advertiser

    theyre testing the CLU056-3626

    the current CLU058-1825 can take 5750 mA
     
  11.  
    CobKits

    CobKits Well-Known Member Rollitup Advertiser

    agreed. in 5 years $1 cobs will be more efficient than the current $10 cobs
     
  12.  
    Dreddd

    Dreddd Active Member

    Guys help i've been trying to find somewhere to buy a few citizen cobs for the past week and the only place i seem to find is fucking digikey, and they are so damn expensive,

    i'm looking for 3500k 90 cri cobs and they seem to be out of stock on both cobkits and northengrowlights..
     
  13.  
    CobKits

    CobKits Well-Known Member Rollitup Advertiser

    ive got 33 gen6 in stock
     
  14.  
    Dreddd

    Dreddd Active Member

    Sorry should have specified, i'm looking for the 5th gen ones since the 6th gen have a different spectrum, 5th gen peak at 630nm while the 6gen peak at 620nm and look like they have more green, am i wrong about this?

    Btw, anyone tried a build with their 97 CRI 4000k cob? that spectrum...
    [​IMG]
     
    Last edited: Mar 8, 2017
    Redoctober and DankaDank like this.
  15.  
    KonopCh

    KonopCh Active Member

    Have you data and pictures/graph with difference between 5gen and 6gen?
     
  16.  
    DankaDank

    DankaDank Well-Known Member

    You're actually correct good eye man, I didn't pick that up.
     
    Dreddd likes this.
  17.  
    CobKits

    CobKits Well-Known Member Rollitup Advertiser

    according to datasheet: gen 5: 450 nm emitter with a 630 peak

    upload_2017-3-8_11-54-9.png

    gen6: 455 nm emitter with a 620 nm peak:

    upload_2017-3-8_11-55-25.png

    i dont have my spectrometer here but will shoot gen 5 vs gen 6 to verify. in any case gen6 tested way higher on PAR in my first test

    upload_2017-3-8_11-57-47.png
     
    Redoctober and Dreddd like this.
  18.  
    CobKits

    CobKits Well-Known Member Rollitup Advertiser

    @Dreddd

    I have some of the 1212-H6K2 ~93 CRIs in gen 5 in 3000 and 3500k. they tested within 1% of the 90 CRIs on PAR
     
  19.  
    KonopCh

    KonopCh Active Member

    So gen 5 has a better spectrum in theory? For our needs here on forum. :)
     
  20.  
    CobKits

    CobKits Well-Known Member Rollitup Advertiser

    "in theory" it has a slightly different spectrum, per those datasheets, which should be tested and confirmed.

    620 and 630nm both have 100% absorbance per mccree. spectrum is only very slightly different yet par is substantially increased in gen 6.
     

Share This Page