Weird behavior from a EX10

[smopoim86]

I have had my EX10 a few weeks (preordered it) and all has been great. Well, today I got a bit adventurous and decided to put a red cree in it. Since its a current controlled driver and puts out under 500ma at max I figured it would be great. I put the led in and all was well. I do not think the led swap has anything to do with my issue, but i mentioned it incase someone thinks it may.

A few min ago i was using it at about half brightness and the inductor whine got louder for a sec and the light shut off. I was using a AW rcr and figured I had accidentally hit the low voltage cut-off on the battery (i'm normally very good about monitoring them). Well, I pulled the battery out and it was at 3.6v or there about. I put the cell back in and it fired right back up. I can't seem to repeat the incident and was wondering if any of you guys have any idea what could have caused it.

1. The flashlight doesn't have any rcr protection, right? (and even if it did there would be no reason for it to be set that high)

2. Could the battery circuit have tripped? (I really dont think it would have gotten louder if that was the case)

 

[yaesumofo]

Sounds strange to me. If you can't repeat the behavior I wouldn't even give it another thought.
When you crack open a light and mod it you really can't expect the company to support you so if it is a problem with the circuit you are basically SOL.
Has your always made a noise?
My D10 is dead quiet.
Yaesumofo

 

[smopoim86]

I'm not sure about primaries, but with rcr it whines at a few places in the ramp. It makes multiple frequencies between about 15-35% and 60-75% at min, in the middle, and wide open it's silent.

I realize the issues with modding a light but like to play with stuff. I took a 2 week old Novatac 120p and swapped the led as well. It's part of the gadgetry addiction.

 

[Tohuwabohu]

According to the Nitecore EX10 Circuit Discussion thread the circuit is boost-only . When the battery voltage is higher than the output voltage at the output current it is designed for it will run in direct drive mode. This is no real problem with a white Cree. But a red Cree has a significantly lower forward voltage leading to a very much higher current with a fully charged lithium ion cell.

I recommend not to use a red, amber or yellow Cree in the EX10.

White, blue or UV Cree's should be ok. I'm not sure about green.

I see that you have already found the Nitecore EX10 UV thread. Try a UV Cree instead of the red one.
I don't know if IR Crees exist. But if you find one don't put it in the EX10.

 

[smopoim86]

Hmm, I guess that's what is it. it acts even worse with a primary. hmm. Know of a good host for a red cree?


EDIT: Well, I put a white back in it and everything works fine. It still screams a bit especially with a primary at max. One thing i did notice was that the point that it turned off last night was when the batt was at 1.6-1.7v, exactly the same voltage that the driver research found as an inflection point.

What would be a good driver to run the red Cree with?