Airwalker16
Well-Known Member
What's the Fv of 1212's?
Matching Drivers and COBs
- Thread starter SupraSPL
- Start date
PhotonFUD
Well-Known Member
My, bad I was thinking 1812s. You could also go 2 1212s in series using ~50w drivers running 700ma that max at 70-75v. Run those series string in parallel as much as you want.
As for how many? As many as possible till I hit the magic 77% efficiency at 3.1w thanks to cobkits data. Works out to around 18, each per 50w driver
Airwalker16
Well-Known Member
So again, what's the forward voltage of 1212's?
PhotonFUD
Well-Known Member
36v at nominal but drops considerably when under driven. fv looks to be around 32v under 700ma so 2 of them will be ~64v.
PhotonFUD
Well-Known Member
LES size will have an impact on coverage that seeing as there is quite a bit of difference in size between the chips.
You are absolutely correct. I was working with 120 degrees instead and wanted to see how far the math would be off from what was found real world. Playing with overlap is going to be the next task at hand. Currently my next project is starting to look like a cookie sheet cram packed full of emitters running uber passive as cobkits calls it. If there is a price drop on the already low price for the 1212s then it isn't that expensive to challenge what you can do with only 400w of power.
PhotonFUD
Well-Known Member
Yeah, yeah, keep in mind that I am planning to run 100w chips at 3w so 10% here and there might add up. Rather check and be wrong so I can correct early.Yeah that's going to make a massive difference /s. Now work out the difference in footprint caused by those 6 mm difference in LES and you're good to go
At 6 inches the diameter is 50cm; the distance from the cob to the outer edge of coverage is ~12 inches. Will have to figure the output at different heights. Lots of variables to play with!
Humanrob
Well-Known Member
Question:
When I originally built my light, I had 4 CXB-3070's running off of a single HLG-185H-1400.
I've rebuilt the light, and for various reason am now running only 2 CXB-3070's off of the same driver.
Can this cause problems? My understanding is its "less efficient", but my understanding ends there... does inefficient mean it will run hotter, shorten the life of the COB.... harm something?
I have not run this for any long periods of time, only wired it and tested it.
Thanks!
When I originally built my light, I had 4 CXB-3070's running off of a single HLG-185H-1400.
I've rebuilt the light, and for various reason am now running only 2 CXB-3070's off of the same driver.
Can this cause problems? My understanding is its "less efficient", but my understanding ends there... does inefficient mean it will run hotter, shorten the life of the COB.... harm something?
I have not run this for any long periods of time, only wired it and tested it.
Thanks!
CobKits
Well-Known Member
you have to hit minimum voltage (50%) to operate that driver correctly. 71V in this case which your two 3070s barely hit and 3590s would not
datasheet has efficiency flat down to 50% load so no loss there
cobs dont care, 1400 ma is 1400 ma they dont care if they have neighbors. at that lower load your driver will now last forever and a day (as opposed to forever). the only thing you are 'wasting' is driver capacity but its there waiting for when you need it again
datasheet has efficiency flat down to 50% load so no loss there
cobs dont care, 1400 ma is 1400 ma they dont care if they have neighbors. at that lower load your driver will now last forever and a day (as opposed to forever). the only thing you are 'wasting' is driver capacity but its there waiting for when you need it again
Humanrob
Well-Known Member
Thank you! I really appreciate your taking the time to explain that to me. I will worry no more.