!!!Sunlight Killed my Zebra Light H-30!!!

[kabkbak7321]

I was sitting in my truck at lunch playing with my zebra light.
(yes I KNOW:shakehead)

When it's set to low, If I let sunlight shine in on the led it go's out,Every time, The same thing.

So I tried my:
ORB NS=Q5 (in pocket)
Luma MRV DIGITAL=Q5 (in truck)
Zebra light h30=Q5 (in tool bag)
Luma M3=Q5 (in tool pouch)
Fenix P2D=Q5 (co-worker)
LUMA-DMINI+Q5 (co-worker)

All on low, When direct sunlight hits it the led go's out completely then when shaded it lights up again (except the h30 it stay's out till you push the button again.

Have any of you seen this happen or do any of you know why this would happen?

I know were your going,And what your going to do next!:nana:

 

[Badbeams3]

I was sitting in my truck at lunch playing with my zebra light.
(yes I KNOW:shakehead)

When it's set to low, If I let sunlight shine in on the led it go's out,Every time, The same thing.

So I tried my:
ORB NS=Q5 (in pocket)
Luma MRV DIGITAL=Q5 (in truck)
Zebra light h30=Q5 (in tool bag)
Luma M3=Q5 (in tool pouch)
Fenix P2D=Q5 (co-worker)
LUMA-DMINI+Q5 (co-worker)

All on low, When direct sunlight hits it the led go's out completely then when shaded it lights up again (except the h30 it stay's out till you push the button again.

Have any of you seen this happen or do any of you know why this would happen?

I know were your going,And what your going to do next!:nana:

Please stop drinking during lunch

I think they just look to you like they have gone out as the sunshine totaly overpowers the glow of the led...:tinfoil::thinking:

 

[LukeA]

We've heard of this before. The consensus of what's happening is that the sunlight is creating a photodiode response from the LED which puts a little bit of current back into the regulator and sometimes that can mess with the circuitry.

 

[LED-holic]

This was well noted in the LF5XT light, by our favorite poster, orcinus. It did seem to be that the sunlight creates a small voltage across the LED and prevents the LED from turning on. It's not a harmful feature because one assumes you don't need a flashlight when you are in the sun.

If this is a bother to you I would then look into getting a replacement. But it seems to be a benevalent side effect...

 

[Yapo]

wow cool...it would be neat if you could recharge the battery by leaving the torch in the sun, although heat could become a problem

 

[Confederate]

I say call it a feature and charge extra for it. Ah, what we can learn from the great Sith Lord, Bill Gates.

 

[milkyspit]

I've seen this... about a year ago I put together a multi-Cree camp lantern for my kids, using my Milky Candle MC2 circuitry... then noticed the LEDs went out when under direct lighting! Took everything apart and rewired several times, checked the LEDs, replaced the driver circuitry, etc., to no avail. Kinda freaks one out to see the LED go completely out, but so far it doesn't seem to be all that harmful. It also seems to happen only when driving at low drive levels.

:shrug: :thinking:

 

[kabkbak7321]

Yes it only happens on light's I have that have a very low setting,I just could not beleave it was happening.

I just think the emiter is jelous of the sun and desides not to perform
when faced with that kind of compation.:shakehead

 

[jirik_cz]

I just think the emiter is jelous of the sun and desides not to perform when faced with that kind of compation.:shakehead

+1 that is the most reasonable explanation

 

[zipplet]

Just tried this with my raw NS on the 20 lumen low, with a halogen 20W light. Staring at the emitter I moved the light from under the lamp to not under the lamp a few times. The emitter goes out when under the lamp!

Does not happen with high drive levels, or funnily enough, on my nitecore D10 at any drive level (my guess is the regulator boosts voltage to overcome the effect).

Interesting thread

 

[Flashlight Aficionado]

Can we have LED flashlight wars?

My flashlight can turn off your flashlight!

LEDs only! Mac's Torch would probably turn off any LED even on the highest setting, if not make it catch fire.

We just need a list of rules for Flashlight Wars 2008

 

[zipplet]

Can we have LED flashlight wars?

My flashlight can turn off your flashlight!

LEDs only! Mac's Torch would probably turn off any LED even on the highest setting, if not make it catch fire.

We just need a list of rules for Flashlight Wars 2008

Fricking hilarious post

From an electrical engineers point of view, I think what happens at a guess is the light causes the forward voltage of the LED to shift significantly. That would explain why the D10 still works even on lowest - driver is compensating. It also explains why the raw NS goes out on the lowest setting.

If I had a bare cree I'd experiment to find out exactly what's up, but I don't. Anyone care to try?

 

[Crenshaw]

so if i point a Tiablo at a D10, the D10 might just go off?

lol!

Crenshaw

 

[matrixshaman]

Fricking hilarious post

From an electrical engineers point of view, I think what happens at a guess is the light causes the forward voltage of the LED to shift significantly. That would explain why the D10 still works even on lowest - driver is compensating. It also explains why the raw NS goes out on the lowest setting.

If I had a bare cree I'd experiment to find out exactly what's up, but I don't. Anyone care to try?

I believe it has been shown that most LED's will act as a photodiode of sorts - that is put enough light on them and they generate a small voltage. Depending on the circuit design of a particular light this can shut off the power to the LED.

 

[zipplet]

Crenshaw: I doubt it. The regulator in the D10 seems to do something (ramping the voltage up?) to keep the LED running. Try it with a direct drive light on low!

 

[zipplet]

matrixshaman: I've seen the effect with 5mm LEDs - try this: Get a high brightness green LED with clear epoxy and wire it to a very efficient dim red LED. Light up the green LED with an incan lamp and the red one will glow. Experimentation is needed to find an LED that will generate enough power.

Edit: Playing around with a 5mm green LED with clear lens - holding it under my halogen lamp I get 0.81V.

 

[NutSAK]

Cool! Can I charge my Eneloops by putting my flashlight out in the sun on low mode? :thinking:

If this is a bother to you I would then look into getting a replacement. But it seems to be a benevalent side effect...

I'm curious--how is this side effect benevolent?

 

[matt0]

Just tried it with my E1B on low. when I turn on my desk lamp to the highest setting and aim it directly at th E1B, it just turns off.

 

[sORe-EyEz]

anyone tried filling the roof with LEDs to compete with solar cells?


think my handheld lights will need shades from now on...

 

[zipplet]

And if you forget the blocking diode, your house will be VERY visible to aircraft at night.