Fenix MC10 switch, ESD warning & video

kramer5150

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Joined
Sep 6, 2005
Messages
6,328
Location
Palo Alto, CA
I have a very unusual switch failure. I think the ESD charge in my fleece sweatpants is causing the electronic switch to turn on the light. If I turn the light off and drop it in my pants pocket the light will turn on if I move around the house. I can very easily get it to do this repeatedly and intentionally. I am absolutely positive I am not bumping the switch in my pocket. I just move around a bit and it turns on.

Does anyone else have this problem?
:thinking:

Heres a video to show what I am talking about.
http://www.youtube.com/watch?v=Qhv-do2d5TU
 
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csshih

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Sep 21, 2008
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San Jose, CA
Re: Fenix MC10 switch, ESD failure & video

shake and bake.. ahahhaaa..
the switch is simply a momentary tact switch which signals the mcu to turn the light on. I'm guessing the static tricks the mcu?
 

sjudson

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Jan 18, 2010
Messages
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Re: Fenix MC10 switch, ESD failure & video

Glad that someone has seen this problem. I believe that the light is coming on by static charge. Try moving across something that you can feel static on, then pull it away quickly, it should come on about 50% of the time. I posted on this months ago and no one seemed to believe me. Let us know what you find out.
 

kramer5150

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Sep 6, 2005
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Palo Alto, CA
Re: Fenix MC10 switch, ESD "failure" & video

Thus far 2 CPF occurrences. So its a rare failure, that only happens in very specific ESD environments. Unfortunately polar-fleece is one of my favorite winter fabrics:mecry:.

https://www.candlepowerforums.com/threads/264913

I don't know if this qualifies as a "failure". The light still works fine, but I am going to have a hard time openly recommending this light to others.... without some precaution. A robust electronic design should not be affected by everyday occurring ESD events.
 

Hack On Wheels

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Nov 4, 2007
Messages
774
Location
Canada
That's pretty interesting! I must say, I was surprised to find my MC10 had turned itself on a couple of times... considering how stiff my switch is. It didn't seem to make sense that the button had been pressed; static, as odd as it sounds, might make a better explanation for those incidents.

I'll make sure to pay attention to this from now on. I've taken to locking it out via the tailcap as a fix though.
 

jimmy1970

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Sep 6, 2008
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Brisbane, Australia
There are just not enough videos of a guys' pocket with a flashlight rolling around inside - I especially like the "shake & bake chicken" reference:D

Great stuff!!:twothumbs

Back on topic, it's a pity about the static problem with your MC10 - with the similar comments from other members, it sounds like a problem that will be experienced by many other users.

I can't think of any other reason this could be happening - might be worth letting Fenix know of your discovery.

James....:)
 
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Locoboy5150

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Joined
Nov 3, 2009
Messages
1,102
I have been trying to replicate this turn on phenomenon with my MC10 and no matter how hard or how long I shake it around in my fleece sweatpants pocket, mine just doesn't turn on. My MC10 has the Osram LED in it, so maybe that has something to do with it.
 
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