Introducing CobKits.com - specializing in DIY and Citizen COBs

mx5spd

Well-Known Member
Thanks CobKits another satisfied customer. Cabinet up and running AK48 mothers sunbathing now. Some crazy reason cant get an Amp reading tried positive side, negative side every which way meter must be toast. Got no idea how hard actually running but dialed it down to a bump above minimum on current. putting out a good 105 Volts

I'm used to wearing a welding hood LOL to look in my red & Blue cabinet now I can groove with my Oakleys. Thanks for answering questions I know it gets old.
 

CobKits

Well-Known Member
just making sure that you know that you cant measure amps without putting the meter inline as the only conductor.. its not like measuring volts. also most meters have a separate port for your red lead when measuring amps
 

DrBlaze

Well-Known Member
Hey Bobby, I'm looking to order some components in a couple weeks or so, and want to get them from you. I'll be lighting a 4x4 scrog, but will be on a bit of a budget, so I thought that 4x1825 driven at 150w (approx 50% efficient) seemed like a good value proposition. Also, I could add more cobs later on if I wanted more efficiency.

However, I remembered an experiment you did a while back where you wired multiple 1212's together on the same heatsink. So I redid the numbers using 4x1212's per heatsink, running at the same 150w per heatsink, and it looks like they'd produce more par and be fair bit more efficient (55-56%) for not much more in cost.

The only thing is how to cool them. It looks like you have only 1 pin heatsink that will accept a fan, and its not very beefy. Are there any other types you can get in? (A square one would be perfect :) ) Also I'm a little unclear on the best drivers to use... there seem to be a couple different ways this could be wired up and I'd like your opinion on which way you think is best. Also, do you favor using 1 large 600w driver or 2x300w+ drivers?

Thanks
@CobKits ^^ ...please comment when you get a chance
 

CobKits

Well-Known Member
thats correct. 4 1212s more efficient than one 1825
in fact 3 are as well. ill get to the rest of your Q in a bit
 

Cabinet Cropper

Well-Known Member
I just wanted to give a shout out to cobkits.com. I had a great experience. Shipping was fast. Everything came as advertised, pricing was competitive. All of these things I expect when doing business. What won me over though, was I had a technical question, I figured it was a long shot, but I decided to call the company anyway. Lo and behold, someone answered, and was down to earth and all too happy to help a brother out (thank you). I will definitely be ordering from them again.
 
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CobKits

Well-Known Member
just tested a hlg-185-54B driver as a single driver solution with 1825 light engine. this driver is a 54V constant voltage driver with external dimming, nameplate rated at 3.45A. The purpose of this test was to determine if we could get good driver utility and external dimming at high currents where the 48B cannot operate due to its 48V cap. all tests are with driver leads open (aka overdriven to 105-108%)

in using it with a single 1825, it tops out near 54V (actually just below :( )
upload_2016-10-28_0-38-5.png

not horrible if you need external dimming, but no advantage over the cheaper hlg-185-48A which tops out right about that same voltage

with 2 1825s on the hlg-185-54B, it looks like:

upload_2016-10-28_0-35-56.png

thats per cob, so 3580 mA total, 182W total. in this case coming up way short to the 48A which would run them at ~112W each. that extra ampacity of the 48A (4.25A over the 3.45A of the 54V model) really is useful in this case
 
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Rocket Soul

Well-Known Member
I just wanted to give a shout out to cobkits.com. I had a great experience. Shipping was fast. Everything came as advertised, pricing was competitive. All of these things I expect when doing business. What won me over though, was I had a technical question, I figured it was a long shot, but I decided to call the company anyway. Lo and behold, someone answered, and was down to earth and all too happy to help a brother out (thank you). I will definitely be ordering from them again.
I completely agree. This is how i would imagine Supra-spl-leds.com if he would have gotten in to that game. Datadriven from practical applications. not a datasheet humper. Patient, helpfull till no end and on point always.
I had a problem on shipping, drivers came separately at no cost to me, cobby picked it up. Always answers straight away any of my silly questions, even if he has a day job. I recommend completely, especially if your stateside and dont have to worry about cuatoms
 

dr.medecine

Well-Known Member
just making sure that you know that you cant measure amps without putting the meter inline as the only conductor.. its not like measuring volts. also most meters have a separate port for your red lead when measuring amps
Regarding measuring ones set up, I understand most is probably already done by you for the set up I ordered (HLG-120H-48A with 2x CLU048-1818C4-353H5K2) if I look around?

My memory is truly horrible and also I do not build lights very often so consider myself noob still and probably always will be unless something change, but I would like to know ones lights. Remember some years ago supraspl wrote something somewhere about building and measuring values but cannot find it now, do you cobkits or anyone else know where I can find a extremely simplified and straightforward guide to do this?

When I say simple think children's book with more pictures then letters hahaha, or at least in that general direction? My English is very basic and often get stuck thinking about the meaning of what I just read when slang, and such language is used or words I don´t get. Probably will not remember what I did a month later anyway but would like to have a noob friendly guide explaining how to extract these values and not just amps but all numbers of value and interest, how it is done using a multimeter. Plugging in to a energy meter give me some very basic wattage, program cost etc from the wall but that is about it and would like a bit more. Would highly appreciate that info or a link to a page containing it, simplified to the extreme if possible?

Sorry about the long text..
 

dabby duck

Well-Known Member
I am looking to buy a modest quantity of these type of heatsinks....

I can't pm or im or whatever, so I figure I will post this....

Can't seem to find anyone with this type of configuration....

1st is

Copper Pin Fin Square with 10-15mm thick base. I am looking for at least 120mm x 70mm in mass [or 2.5"] or at least something like .5 c/w for new Vero 29...70+v versions?

square copper pin fin.png

and then these strip type pin fins for the Samsung or Cree from Cutter rail type led strips...

strip aluminum pin fin.png

Thank you!
 

The Dawg

Well-Known Member
I am looking to buy a modest quantity of these type of heatsinks....

I can't pm or im or whatever, so I figure I will post this....

Can't seem to find anyone with this type of configuration....

1st is

Copper Pin Fin Square with 10-15mm thick base. I am looking for at least 120mm x 70mm in mass [or 2.5"] or at least something like .5 c/w for new Vero 29...70+v versions?

View attachment 3819630

and then these strip type pin fins for the Samsung or Cree from Cutter rail type led strips...

View attachment 3819632

Thank you!
 

CobKits

Well-Known Member
have no fear the sphere is here :)

i did not know this but it actually opens- which is awesome because now instead of just bare chips we will be able to test small assemblies and answer questions like:

-how much does this lens/reflector attenuate overall light?
-what is the absorbance effect of putting this high surface-area black heatsink into a room
-how does a given multi-chip configuration fare
-single diode strips vs cobs

etc
 

Bigfries

Active Member
Hey!

So I'm looking at building a COB to cover a 4x8 space on a budget.
Here's what I'm thinking-
32 Citi 1212 (80 cri or 90?)
7 HLG 240h-c ( better options? )
32 105mm pin fins

How's that look to you? Any suggestions?
 
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