10.8V Packs Are For M@G 85's Not....

[Youfoundnemo]

LED's


I spent all day trying to solder a couple led's up to a Mag, I was using 3 cree's and a metal round for a heat sink (I have no clue what you call these, we use them when roofing, we're roofing now so I had a bunch stuck in my pocket) I got all the leds soldered up in parralel, which was a PAIN, tested it with a IMR 16340 I had laying around, installed it in the mag head, and started on my demolished mag switch (I threw away half the peices when I switched hosts) I..."reengeinered" that and then realized I had no D batteries.🤢

Well I dont know where I heard it but somewhere I heard that led's are curent based and that voltage didnt matter😱 (so long as it was above the Fv) Well after hearing that I went ahead and popped my battery carrier in a full 10.8v... clicked the switch and nothing happened:thinking: soooo I pulled the head off the light and pulled the pack out... no obvious problems, pulled off the switch cover (btw where are the glow switch covers from sabrewolf) and noticed that the switch assembly had moved forward some... I repositioned it and really cranked on the allen key so I wouldnt have anymore problems from it....

Reassembled everything, pointed the light at the floor and click.... Light, ugly blue light....typical of LED's right:green:, clicked it off and waited a moment thinking that this couldnt be right, it was bright white when i was using the IMR.... clicked it on again, this time looking at the bezel well I saw one flash from well Im not sure what it was that sparked, I figure it was one of the bond wires or something.... I guess I effectivly instaflashed a LED


Incan has always made me happy, I think I will stick to them for a while now...😎


Thanks skillet, put the parts in a new host and my my does it look purdy =P

 

[lolzertank]

Ouch. LEDs are current driven in the sense that you want to maintain a constant current. However, the current is dependent on the voltage and very small changes in voltage result in huge current changes.

Better luck next time!

 

[325addict]

Exactly! A LED is a diode, which happens to give off light when a current flows through it :thumbsup:

Under Vf, no current flows at all, causing the LED not to light up at all. When turning up the voltage, there will come a moment, the Vf is met, from this moment a current will start to flow.

Increasing the voltage will then start a process of heavily increasing current! When applying a HARD voltage (that is, without any current limiting resistor of current source in between) your LED will die quickly.

Applying a hard 10.8V from a powerful battery is a SURE way to kill a LED. Well, even a 7.2V battery would have done this :sigh:

Yeah... incans rule :twothumbs
Just put a 13V setup together with my M90 Rattlesnake! (again)
Yes, indeed, now still on 18500s, but as soon as you got in the longer extender, I'll soon be able to use 18650s for this setup :thumbsup:

Timmo.

 

[jchoo]

You now know the definition of "angry blue".

 

[xenonk]

Ouch, angry blue death.

Yes, current-based isn't exactly what it sounds like. Semiconductors like LEDs aren't much different from any other piece of wire that will pull as much current as it possibly can at a given voltage, except that they have a threshold to overcome before they start. That threshold even varies between samples due to manufacturing tolerances. They're current-based because you need to control the current flow in spite of this. 1 amp = bright light. 2 amps = smoke signals.

They might have survived 10.8V a little better if you had them wired up in series. Depending on the Vf of the samples, their combined voltage drop may have kept them from pulling a hojillion amps.

The moral of the story is that both types of light go at 3x the rated voltage.