Help with Veleno D2s

I hope this is the correct forum.

I have 4 Veleno D2 flashlights.
The 3 brushed finished ones have the small black square QTC.
The black finished one has a small white round QTC.
Can someone tell me about this?

Your question is too vague.

Do you mean tell you about QTC?
It's a kind of resistor that will change its resistance on pressure.
https://en.wikipedia.org/wiki/Quantum_tunnelling_composite

Simple word: the more you push the QTC, more electricity current will through it.

I'm sorry for being vague.
I've read everything here about the Veleno Ds and I never seen anything about a round white QTC.
I thought they all used the black square QTCs?
So was my black QTC replaced with the white one?
Is there any difference?
Did Veleno use the white ones too?
Just want some information on this white QTC?
Thanks guys.

Moving this to LED Flashlights forum.

Bill

I have 3. I just checked and they all have the black square. Thats all I know.

You could send an email to Steve Ku at Veleno Designs via his website. I had cause to email him and he was quick to respond and helpful.

RGRAY said:

I'm sorry for being vague.
I've read everything here about the Veleno Ds and I never seen anything about a round white QTC.
I thought they all used the black square QTCs?
So was my black QTC replaced with the white one?
Is there any difference?
Did Veleno use the white ones too?
Just want some information on this white QTC?
Thanks guys.

Click to expand...

Have a picture? Always been black and square for my lights.

Here is a picture.
It works just like the black square.

Hey RGRAY, the picture on the right looks like something is attached on top of the QTC and the QTC is underneath.

euroken said:

Hey RGRAY, the picture on the right looks like something is attached on top of the QTC and the QTC is underneath.

Click to expand...

No, I contacted the original owner.
He said he had a chipped black square and Steve sent it to him.

OK,
I have another question.
I got my Damascus 40DD today and the QTC is in the bottom not top.
All my other Ds have it in the top.
1 Would that have come like that?
2 Is there a reason for it?
3 Which way does the battery go in tip down or up?
4 Does it have anti-reverse protection or could I fry it?

Earlier versions have the QTC on the bottom of the tube with magnet built in at the bottom of the tube to hold QTC in place. New versions have the magnet on the PCB under the LED where the QTC sits.

+ end of the battery goes towards the LED. I have never tried reversing the polarity but since it doesn't really have a driver, it probably won't do anything as the light is basically direct driven.

If LED for some reason goes out, it is very easy to replace by reflowing a new led.

RGRAY said:

No, I contacted the original owner.
He said he had a chipped black square and Steve sent it to him.

Click to expand...

If the QTC is not visible at the bottom of the tube and not at the top, and the light still has variable output, I'd take out the light engine by unscrewing the retaining ring and check under the metal you see in the picture. There should be QTC there somewhere

I don't know what you mean,so I don't knwo what I can do to help.

This is interesting.

I have six Steve Ku and Veleno's in different models, but only three of the six have a visible QTC, which is the black square. Two have it in the head and the other is in the tail. No circular white ones.

I only have (2) D2s and both have square black QTCs on the head side. I know some of the custom DDs prior to the D2 had the QTC in the tail. It is interesting to see there may have been a white one.

One thing I learned was that the QTCs wear out. I didn't really nice as they wear out gradually, but when I purchased new ones from Steve I basically had new lights. My D2s are so much brighter now.