DIY Passive cooling with PIN Heatsinks SST120 and SST140

sixstring2112

sixstring2112

Well-Known Member
yeah at that price i can see how they went fast.i woulda took 30 or 40 but i didnt want to be a hog and i already have an order with plc and also waiting on mark at cutter to answer me.just wanted to snatch 10 cause they were cheap.oh well ya snooze ya lose lol
 
sixstring2112

sixstring2112

Well-Known Member
robincnn said:
With no air movement the old 140mm get a little hot to touch (exceed 55C) but still not an issue for the COB. They should be fine with air movement in grow space.
The new 140mm since last month have 70mm pins instead of 60mm so they can handle 75w better.
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well then fuck it,put me down for 4 of those 72v 3590 and ill get em with the heatsinks when they arrive? i got 2 1050ma drivers in the pile i can burn on this lil experiment lol
 
sixstring2112

sixstring2112

Well-Known Member
robincnn said:
will reserve 4 for you. I also have a 2100 driver and plan run 36V @ 75 watts on the new 140mm heatsinks with khatod optic
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Im thinking once i get those heatsinks and now those 72v cobs i might design a panel that has the 4x 75w cobs on the 4 corners and maybe 2 x rows of 3 or 4 cobs driven @ 1050ma so theres no hot spots in the center.i could even leave the ledil reflector off those 75w and tilt them slightly away from center.maybe make a panel that covers 4 x 6' space i have. All drivers remote again and i def have a wall fan in that spot to blow air past the heatsinks
 
robincnn

robincnn

Well-Known Member
sixstring2112 said:
Im thinking once i get those heatsinks and now those 72v cobs i might design a panel that has the 4x 75w cobs on the 4 corners and maybe 2 x rows of 3 or 4 cobs driven @ 1050ma so theres no hot spots in the center.i could even leave the ledil reflector off those 75w and tilt them slightly away from center.maybe make a panel that covers 4 x 6' space i have. All drivers remote again and i def have a wall fan in that spot to blow air past the heatsinks
Click to expand...
What driver. 72x4 exceeds the Ideal holder rating of 250
 
sixstring2112

sixstring2112

Well-Known Member
robincnn said:
What driver. 72x4 exceeds the Ideal holder rating of 250
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No im planning to just use 1x 1050ma driver per 2 x 72v cob so 2 drivers 4 cobs.there will be some extra voltage there but its what i have the most of.i wonder if those hgl185-1050 would actually drive a 3rd cob @72v anyone try it?
 
nogod_

nogod_

Well-Known Member
Truth, except Robin raised the issue that 4x 72v exceeds the max voltage rating for any cxb3590 compatible holder.

I have a few 4-bar builds pushing 288v thru ideal holders and havent burned the house down. But that was built before knowing the cap on the holders and after buying a 50pack of 72v cxa3590s.

A workaround would be doing two parrelel strings of two 3590s in series on a 1.4a meanwell. You can avoid individual voltage descrepancies by matching over/under cobs with each other and evening out the strings.

Both not ideal (no pun intended). Hopefully we'll get a high(er) voltage version of cob holders soon. Until then, 36v just makes more sense.

PurpleBuz said:
I will, once I figure out how many. gee robin your always so helpful!

I'm sure they will go fast once people realize running them at 700ma is equivalent to running the 36V at 1400.
Its also easier to supplement with monos at 700ma.
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P

PurpleBuz

Well-Known Member
yes true. forgot about that I usually work with smaller LES cobs. I can do my own holders, guess that's too much for quick erector set builds.
lol so maybe robin wants to make a special deal on them for a bunch :)


nogod_ said:
Truth, except Robin raised the issue that 4x 72v exceeds the max voltage rating for any cxb3590 compatible holder.

I have a few 4-bar builds pushing 288v thru ideal holders and havent burned the house down. But that was built before knowing the cap on the holders and after buying a 50pack of 72v cxa3590s.

A workaround would be doing two parrelel strings of two 3590s in series on a 1.4a meanwell. You can avoid individual voltage descrepancies by matching over/under cobs with each other and evening out the strings.

Both not ideal (no pun intended). Hopefully we'll get a high(er) voltage version of cob holders soon. Until then, 36v just makes more sense.
Click to expand...
 
Airwalker16

Airwalker16

Well-Known Member
PurpleBuz said:
yes true. forgot about that I usually work with smaller LES cobs. I can do my own holders, guess that's too much for quick erector set builds.
lol so maybe robin wants to make a special deal on them for a bunch :)
Click to expand...
You make your own? So how do you avoid this voltage limit? By soldering wires straight to the pads or what?
 
welight

welight

Well-Known Member
sixstring2112 said:
yeah at that price i can see how they went fast.i woulda took 30 or 40 but i didnt want to be a hog and i already have an order with plc and also waiting on mark at cutter to answer me.just wanted to snatch 10 cause they were cheap.oh well ya snooze ya lose lol
Click to expand...
I sent you a PP request did you get that?
Cheers
Mark
 
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