Summary of SupraSPL's advice on building DIY COB's

VegasWinner

Well-Known Member
·
Recommended tools:
Multimeter with 10A current measuring capability
Power meter - KillAWatt or EnSupra (no affiliation)
Wire stripper
Wire crimper
Slide Connectors
Heat Shrink Tubing
Tools: wire stripper , drill, drill bits 1/8, 5/32, 3/16, 3/16-NC18 tap

· Misc: solder, shrink tubing, 18ga wire I use solid wire not twisted for my application, because I'm using cob holders that eliminates having to solder wire to cobs, wing nuts and #8 x 1/2" self tapping screws, thermal grease

· Parts 8 - Cree CXA 3590, 8 - Ideal 2303CR(cob holder),




Drivers:



Do you have drivers picked out? The CXAs excel at being driven soft while the Vero29 excels at being driven hard. But if you do drive the CXA hard, they will still grow some serious nugs. Here are a few drivers that I know will work for CXA3590

300mA, $3 (drives 1 CXA3590)
300mA, $7 (drives a pair at 280mA)
300mA, $8 (plastic shell, should drive a pair @ 280mA)
350mA, $56 (drives 3, dimmable)
500mA, $70 (drives 5, dimmable) HLG-185H-C500A
700mA, $70 (drives 3, maybe 4, dimmable) HLG-185H-C700A
1050mA, $70 (drives 2, dimmable) HLG-C185H-C1050A

The HLG-120H-C series would work, $64 ea.



LDD 12/12 1W LED driver for fans
https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&langId=-1&productId=2142061&storeId=10001&krypto=vFgRhKXJZKuM8sLfuPRmxv3tw+Np1UpMVks4N7ZnwCWNPBgNGYKl3Q==&ddkey=https:StoreCatalogDrillDownView

Heat Sinks:

At 700mA (51W), a 12-20" spread between COBs is doable, depending on the canopy size you need to cover. If you are planning on using active cooling, for (4) CXA3590s (204W)
-3.5" profile - 46" length
-4.23" profile, 36" length
-4.6" serrated, 17.5" length
-4.9" profile, 25.5" length
-5.375" profile, 17.5" length
-5.88" profile, 23" length
-7.28" profile, 17.5" length
-8.46" profile, 15" length


But if you are thinking passive cooling, with a little help from your circulation fan, basically triple the lengths above. I am still experimenting with reducing the passive cooling numbers though, you might be able to get away with a lot less if your circulation fan is hitting them.

COB:

COB spacing can be tricky. I suspect the most beneficial thing we can do for the plants is try to space the COBs in a pattern gives the most even light spread (staggered) rather than spacing them with an eye toward heat management. That said, those heatsinks have a nice thick base (.3" or 7.62mm) and thick fins, so they should have a relatively low temp gradient no matter where you place them.
 
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sanjuan

Well-Known Member
Many people prefer Wago 222 "lever nuts" to generic wire nuts.

Edit: there is now a 221 series. Amazon reviewer: "The new version is clear so you can check that the wires are properly inserted, smaller so it will fit more easily into tight boxes, and the lever is easier to use. Maximum wire size is still 12AWG solid or stranded. The only downside: minimum wire size is 24AWG (compared to 28AWG with the old version)."
 
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