Gransee
Flashlight Enthusiast
I have realized that the specs on the rev2 LS circuit driving the LED at 400mA is not correct. The original circuit from Wayne (dat2zip) was set for 400mA to the LED but we changed it in production to increase run time and reduce heating. I simply just did not keep track of this and continued to tell people that we were driving the LED at 400mA. I did not intend to deceive but just simply did not realize the 400mA number was no longer correct. My apologies. The correct current (verified with Wayne today) is centered around 330mA using a .15ohm sense. With variations in the chip, sense resistor, etc. The current to the LED will very by as much as +-10mA, which is a range of 320-340mA. Current consumption on the battery side varies (largerly due to the Vf of the LED) from about 420mA to 500mA. ~1.3-1.45w in and ~1w out. This puts converter efficiency at about 68-75%.
Wayne, please let me know if any of these numbers seem out of line to you.
I will tell you that we have data from people who have taken apart our competitor's regulated luxeon flashlights. This data indicates that Wayne's circuit is the most efficient converter in any commericially manufactured luxeon flashlight on the market.
The brown board units we made last year which we called 500mA units were actually running with a .12ohm sense which works out to around 417mA, not 500mA. Those units did not have enough run time in our opinion.
The reason I am posting as precisely as possible about our circuit is because I want to undo my misinformation. I do strive to be as honest as I know with you guys. In my defense, I do have a lot of things to keep track of and I lately just don't get into engineering as much as I prefer.
So it turns out that we are actually under driving the LED after all. I consider this good news because I am pleased with the output and run time that the .15ohm resistor is giving us. I definately do not want to increase the power anymore (as the brown board units verified). The fact that our housing heats up so quickly is even more testimony to the effectivness of our internal heatsink now that I know we are underdriving the part. I feel like the flashlight will now last longer than I originally thought.
Anticipating the CPF questions, I do not want to release a higher power unit at this time. I do not feel that it is in line with our EDC "arctype".
Again, my apologies for the misinformation.
Peter Gransee
Wayne, please let me know if any of these numbers seem out of line to you.
I will tell you that we have data from people who have taken apart our competitor's regulated luxeon flashlights. This data indicates that Wayne's circuit is the most efficient converter in any commericially manufactured luxeon flashlight on the market.
The brown board units we made last year which we called 500mA units were actually running with a .12ohm sense which works out to around 417mA, not 500mA. Those units did not have enough run time in our opinion.
The reason I am posting as precisely as possible about our circuit is because I want to undo my misinformation. I do strive to be as honest as I know with you guys. In my defense, I do have a lot of things to keep track of and I lately just don't get into engineering as much as I prefer.
So it turns out that we are actually under driving the LED after all. I consider this good news because I am pleased with the output and run time that the .15ohm resistor is giving us. I definately do not want to increase the power anymore (as the brown board units verified). The fact that our housing heats up so quickly is even more testimony to the effectivness of our internal heatsink now that I know we are underdriving the part. I feel like the flashlight will now last longer than I originally thought.
Anticipating the CPF questions, I do not want to release a higher power unit at this time. I do not feel that it is in line with our EDC "arctype".
Again, my apologies for the misinformation.
Peter Gransee
