Lexel is making a BLF GT driver for this light. The carrier is easily converted to 12v.
So if you bought it and the driver crapped out on you, you could replace it cheaply. Something to think about.
Would the driver have Narsil UI by chance?
Do you know what the actual lumen and lux numbers are? I know that it does not make the stated 3,000 lumens.
Yeah. Look here.
Do you know what the real output numbers are? I know it does not make 3,000 lumens?
There are none, it’s just a driver.
“Real output numbers” depend on many different factors.
Going from 2500 to 3000lm is almost impossible to tell.
I think he was refering to the MF02, not Lexels driver. His driver can supply up to 3A, but can be adjusted down to whatever you want. 2.5A is what the GT uses.
Maukka’s review showed 2,200 lumen output.
It might be best to talk about the MF02 on a different thread since this one is about the cft-90.
Yes, I guess you are right. It’s funny how easy it is to start talking about one thing and then the conversation goes in another direction.
The Luminus CFT-90 is such an amazing LED. Is Sky Lumen the only one who makes a CFT90 flashlight? I did an internet search and found nothing? Is this LED just plain too expensive to attempt manufacturing flashlights with it? It truly feels like the flashlight manufacturers are dead-stopped at the CREE XHP35 HI and nothing beyond that is going to happen for the foreseeable future?
That emitter costs more then a lot of complete flashlights. That’s one reason you don’t see many lights using them. I imagine the Chinese flashlight market doesn’t see any profit using it.
The other, bigger reason is it requires a special driver to power it. Richard at Mountain Electronics is the one who built the driver for Skylumen, but I don’t think he’s offering them to the public yet. Lexel is also working on a driver for that emitter. I recall someone mentioning a third person who is working on a driver, but I can’t remember who it is. No driver, no light.
Yes, it’s too expensive for normal flashlights. You would probably need to pay 700-1000$ for such a light.
Thank you so much for that great explanation, and bringing me up to speed! :innocent:
I calculated cd/lm of CFT-90 based on SMA test.
Eyeballing the chart is not precise, but I got 0.36-0.367 cd/lm.
It should be 0.318 cd/lm
So unless I did something wrong, there seems to be ~14% error somewhere in the sma’s setup.
huh? I do not see the need for a special driver, it is a normal 3V led, it just can handle an enormous current. Is there reason why a bunch of parallel 18650’s and a 5-dollar BLF-A6 driver would not drive this led to 25 amps?
They’re obviously is a reason, but I don’t know it.
Maybe because it needs 40A to outperform the GT and make it worth the trouble and expense? That’s my guess.
I will ask Lexel why it needs to be special.
The A6 is a FET driver, right? Lexel said using a FET driver is not really an option for such an expensive emitter.
I assume he means it would be very likely you could burn it up. How would you like a $5 driver to burn up a $150 emitter? That would suck.
I’m sure you could ask him for more details. Here is his CFT-90 driver thread. Well, not a driver build thread, but the closest I could find.
The driver design is a buck.
How could you kill an emitter that withstands 40A? Heat I guess?
I guess he meant that it’s wasteful to drive such expensive emitter without precise current control. If you spend this much, it’s worth to spend some extra and really get the best of it.
Though in this case that “some” is actually large.
Non of my Lambda lights used anything like Lexel’s driver. Most of those that used the Luminous 90s were $70-90 emitters. Never had any burn up. But they best they could manage was 13-16A though and that is running on 4c or 4d cells. So I just wonder if it’s difficult just to get up to 40A without getting to the point where you get way beyond that.
You can use a fet driver , but due to the high Vf it can “only” draw up to 18-20 amps .
High Vf? 3.47V at 20A is high?
Divide it between 4 strong batteries and they’ll keep 4.15V.
This leaves us with 35 mOhm resistance in everything between LED and battery, I’ve seen report of resistances as low as 10 mOhm.
I’d expect 30A to be easy for our masters (15 mOhm).
With 8 batteries and 10 mOhm host there would be over 35A.
But Vinh reported getting just 20A. So something doesn’t add up.