My Emisar D4 is a “touch” light?

Lexel · 2018-12-20T04:38:12.000Z

ZED:

Sorry lexel I was respondeing to moderator007. That makes sense and without the knowledge of specifics is kind of what I was thinking. I bet you my ground (black) wire is touching the MCPCB. cause for alarm or is it fine?

if its a dead short with worn anodisation on threrad it leads to DD turbo light if tail cap gets twisted on
if its just some conductive residue light will constantly light up at a low level

moderator007 · 2018-12-20T04:40:13.000Z

It looks like you have had this light for awhile. Did you recently mod anything or take it apart?

everydaysurvivalgear · 2018-12-20T04:45:00.000Z

Looks fairly normal to me the part of the bezel you are touching has no anodizing left on it? So you have current leaking into the MCPCB from some where.

NWoodsman · 2018-12-20T04:59:24.000Z

I swear this just came up elsewhere. The FET has no bottom limit on the voltage it senses. It acts like a gate, and the human body voltage is opening the FET allowing a high enough voltage to leak off the battery and glow the emitters.

Lexel · 2018-12-20T04:55:06.000Z

NWoodsman:

I swear this just came up elsewhere. The FET has no bottom limit on the voltage it senses. It acts like a gate, and the human body voltage is opening the FET allowing a higher voltage to leak off the battery.

wrong the FETs gate is grounded with 100k and the MCU pin at ground too so there is no way you can activate the FET in any way

chadvone · 2018-12-20T04:59:45.000Z

Lexel:

so you act as cinductor between head and Tube bypassing the driver

I didn’t think the head threads of the D4 were anodized, but I just looked and they are on mine. I tried to duplicate this with a led some wire and and a 18650. I couldn’t get any light no matter the combination I held them in other then just wiring it up.

I would guess there is some power bleeding through the driver/head contact. But that is just a guess.

Lexel · 2018-12-20T05:15:06.000Z

chadvone:

Lexel:

so you act as cinductor between head and Tube bypassing the driver

I didn’t think the head threads of the D4 were anodized, but I just looked and they are on mine. I tried to duplicate this with a led some wire and and a 18650. I couldn’t get any light no matter the combination I held them in other then just wiring it up.

I would guess there is some power bleeding through the driver/head contact. But that is just a guess.

the conductive connection does not need to be on the MCPCB can be on driver as well

I thimnk there are different versions of D4 lights very old had blank machined MCPCB shelf while others were anodized

NWoodsman · 2018-12-20T05:32:36.000Z

I still rule out ground short. The wear in the anodization is the clue, his body is essentially a battery and his touching the head and tail means he is applying a reverse voltage to the deanodized ground which is backtracking across something. If not the FET than maybe directly across the emitters. Do you live in an extra dry place with static electricity? A 4000v static charge can overcome a 100k resistor.

Edit to add: the more surface area he grips the light with, the brighter it gets. Something is turning his body’s milivolts into a nice smooth boost up to at least around 2.3v.

Lexel · 2018-12-20T05:32:21.000Z

NWoodsman:

I still rule out ground short. The wear in the anodization is the clue, his body is essentially a battery and his touching the head and tail means he is applying a reverse voltage to the deanodized ground which is backtracking across something. If not the FET than maybe directly across the emitters. Do you live in an extra dry place with static electricity? A 4000v static charge can overcome a 100k resistor.

there is no way you overcome the MCU dead ground to FET gate and its totally insulated from the body, I mean there are ate least 2mm space between the driver rim and those resistors and heads driver rim is anodized
the LED- has connection to the head part of the flashlight which is insulated from driver and tube, touching now tube and head makes a connection,
touching tube and head with a copper wiore may lead to turbo if there is really a short between LED- and head

NWoodsman · 2018-12-20T05:57:02.000Z

In the video, he grips the tail and lightly taps the rim of the bezel. His one hand is not directly touching head and tube. There is no way he is completing the li-ion circuit across his torso from one hand to another enough to put 2v across the LEDs.

That doesn’t change the fact that his gentle touch is somehow causing 2v to appear from nowhere.

EDIT: Ok nevermind. My new theory is that he is in a room with a lot of RF signal. His body is acting like a crystal radio and attenuating the atmospheric voltage straight across the leds.

g_damian · 2018-12-20T07:51:54.000Z

What if during reflow led negative was shorted to the MCPCB?

That could explain why touching tail (negative) and head bypasses the driver and turns on leds.

varbos · 2018-12-20T17:25:15.000Z

I don’t know what is causing this but I have forwarded the video to the CIA and the man said they are very interested in studying and/or dissecting you.

jon_slider · 2018-12-20T17:46:41.000Z

ZED:

I’ve swapped LEDs in this one I don’t know how many times.

https://www.youtube.com/watch?v=614gjgNEwXk&feature=youtu.be

thanks for the video!

hank:

You’ve clearly got a current leak path somewhere in the head of the flashlight.

I agree. The LED swaps have a short.

ZED · 2018-12-20T17:46:49.000Z

g_damian:

What if during reflow led negative was shorted to the MCPCB?

That could explain why touching tail (negative) and head bypasses the driver and turns on leds.

I believe this has something to do with it and is probably the case, however I don’t totally understand how it’s doing it. I’ll report back after work and take the head off and check. It’s pretty cool, freaks people out

X31 · 2018-12-20T19:14:54.000Z

My Black Flat D1 does this, so I guess it’s a short between thermal pad and cathode

Lexel · 2018-12-20T20:45:49.000Z

NWoodsman:

In the video, he grips the tail and lightly taps the rim of the bezel. His one hand is not directly touching head and tube. There is no way he is completing the li-ion circuit across his torso from one hand to another enough to put 2v across the LEDs.

That doesn’t change the fact that his gentle touch is somehow causing 2v to appear from nowhere.

EDIT: Ok nevermind. My new theory is that he is in a room with a lot of RF signal. His body is acting like a crystal radio and attenuating the atmospheric voltage straight across the leds.

the 2V are not appering from nowhere they appear from the build in battery
the other 2V just drop over his body, the harder he touches the light the less resistance he has so the current increase

ZED · 2018-12-20T20:51:25.000Z

~~X3~~:

My Black Flat D1 does this, so I guess it’s a short between thermal pad and cathode

Speaking of that, do you recommend putting a flat black in the d1? I know it’s dimmer but just curious how you like it and if it’s okay with direct drive FET.

hank · 2018-12-20T20:51:58.000Z

It’s pretty cool, freaks people out

Tell’em you’ve invented cold fusion.

Jerommel · 2018-12-20T21:04:23.000Z

ZED:

~~X3~~:

My Black Flat D1 does this, so I guess it’s a short between thermal pad and cathode

Speaking of that, do you recommend putting a flat black in the d1? I know it’s dimmer but just curious how you like it and if it’s okay with direct drive FET.

No problem with a DD driver because the Vf (forward voltage) of the Black Flat is very high.
But as i understand it from Hank Wang’s explanation, the D1 reflector is designed or suited) for XP-L HI.
A BLF member tried a White Flat 1mm² in it and it was impossible to focus properly.
Now the Black Flat has a 2mm² die, but that’s still twice as small (surface area) as an XP-L HI.

X31 · 2018-12-20T21:05:56.000Z

ZED:

~~X3~~:

My Black Flat D1 does this, so I guess it’s a short between thermal pad and cathode

Speaking of that, do you recommend putting a flat black in the d1? I know it’s dimmer but just curious how you like it and if it’s okay with direct drive FET.

Well, I use a low current battery (lgabf1l1865) and get about 60kCd (measured at 10m).
It draws 3,4A from the battery so I guess the LED is safe.