L2D-CE flashes when switched on

Dr.K

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Joined
Aug 31, 2007
Messages
261
Location
Webster Parish Louisiana
I found the remedy. loosen the head a full turn or so instead of just enought to turn off turbo. the opposing force of your fingers and thumb (while clicking on) are activating turbo mode only until you release the clicky (a split second). check it out.
 

stamat

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Joined
Oct 28, 2005
Messages
44
I found the remedy. loosen the head a full turn or so instead of just enough to turn off turbo. the opposing force of your fingers and thumb (while clicking on) are activating turbo mode only until you release the clicky (a split second). check it out.

I have to disagree. The pre-flash is there in the low power mode of my L2D, regardless of how many turns.

When my eyes are dark adjusted it is blinding. I turn the flashlight to see something and for a moment my ability to see gets worse instead of better.
:thumbsdow

I greatly prefer my original (Luxeon) L1T :thumbsup:
 

L.E.D.

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Aug 4, 2001
Messages
984
Location
Arizona
One interesting thing to note about the L2D CE flash is it is an extremely quick pulse, at least as quick as a nice strobe. If you point the beam right at a ceiling fan that is spinning at its fastest rate, you'll notice the flash "stops" the fan perfectly in one frame. You can also do this continuously by tapping the switch really fast, keeping it depressed for less than 0.2 seconds each tap. It should stay in low mode between each tap when executed correctly. If you're too slow, it will just switch to medium high and strobe, as this actually takes quite a bit of clicking finnese. May be useful for timing cylinders on an engine?
 
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MikeSalt

Flashlight Enthusiast
Joined
Jan 10, 2007
Messages
1,948
Location
Stoke On Trent, Staffordshire, UK
I notice something similar with my P1D-CE. When I go from 'high' to 'low' very quickly (it goes med-high-low-strobe-SOS), the low mode comes on a little bright, then tails off within less than a second to normal 'low' mode.

What I can assume (having never opened the head) is that the circuitry is very rapidly pulsed PWM, and this is smoothed out by a tiny capacitor so you cannot notice the dreaded 'PWM' flickering. When you change modes, a little bit of charge is still left in this capacitor from the higher modes. This causes the flash, or in my case, the quick tail-off. It is not likely to be a fault at all.
 

PegAir

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Joined
Oct 25, 2006
Messages
42
I've wondered if this was done intentionally for the LED. Does the brief intense flash help the LED's color, brightness, or efficiency before being placed back into the lowest power setting?

Using an outdoor "how far can I see" test, I'm reasonably sure the flash is at high, and clearly brighter than medium.
 
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