Luminus CFT-90 Testing - The Mother of all LEDs

Flashlight Modding and DIY Parts
177

Yes, it’s too expensive for normal flashlights. You would probably need to pay 700-1000$ for such a light.

178

Thank you so much for that great explanation, and bringing me up to speed! :innocent:

179

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.

180

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?

181

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.

182

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.

183

How could you kill an emitter that withstands 40A? Heat I guess?

184

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.

185

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.

186

You can use a fet driver , but due to the high Vf it can “only” draw up to 18-20 amps .

187

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.

188

I wish i knew what’s the truth ! would like to test a cft-90 but 100€ isn’t that cheap :wink:

189

Just like any other emitter, too much voltage will either kill the emitter or your batteries due to exponential current increase.

190

Aren’t they any manufacturer papers of this led?Have you made any search about it?

191

https://nl.mouser.com/datasheet/2/245/Luminus_CFT90W_Datasheet-1129831.pdf

192

I see “high current operation: up to 27 A DC”.So,how it could go up to 40A?

193

Please read the first post(s) of this thread.

194

LEDs can be driven past the recommended manufacturer specifications.
This is what enthusiasts do and is the entire point of this topic, if you even read the first post.

195

I see.So,I wish some of you can put it in a GT,test it and share the specs with us,so as others follow. :slight_smile:
Thank you all.

196

Are you not aware that this has already been done? Vinh over at Skylumen has built several GT’s with this emitter. His posts are mainly on CPF.

Over here, Lexel has already fitted it into a GT, check out this thread.