Q8, PMS SEND TO THOSE WITH ISSUES BLF soda can light

Pity he didn’t catch 768 :slight_smile:

I just had to double check... That was much faster than I had thought...

Are these small SMD LEDs really that different from the larger emitters? I’ve driven those down to ridiculously low levels (as in: I had to put the light to my eye in a dark room to see if it was on) and have never seen any kind of knee in output. There’s a lot of speculation going around but I’ve yet to see any hard facts on why the LEDs act like they do (eg. someone putting a scope on the LED to measure something).

Mine has just begun to act up as well. I’m working on a video. Here goes: https://youtu.be/uFwYC6rlSa4

The light is otherwise in line with what others have seen: some good screws, some stripped (but likely removable) screws, minor scratch on the tailcap, works great. I just wish the tube was an inch longer.

I put the cells in the charger for a few minutes and the indicator is working again. Seems like the Vf theory might have some merit after all.

Well I ordered some lights in the first batch to give away. And it will still take sometime before I get them. I am used to 6-8 week shipping so no worry yet.

Testing imgur

How to show picture

How do i make the picture show up without link ?

Take a look at this simplistic view:

We are operating right down at the ~ 2V region where curves converge, tend to be more horizontal and all bets are off. The dotted line at 20 mA is where they start coming on-song, predictably.

Edit Ours are being run at less than 1/100th of that level.

If you had real data on these specific diodes, from a specific batch, and plotted on a log scale, I think (surmise) that they would be operating in a very non-linear (and undocumented) region at these current densities, depending on the area of the junction, indirectly related to size of the die. They don’t behave much differently from a basic PN diode, just the “switching region” between conduction and not, is raised in voltage (e.g about 0.6v for plain silicon) Leds have a different band-gap, depending on frequency (colour) of light emitted.

And they are made of compound semiconductors, not silicon (Gallium, Indium, with Arsenic doping to name a few), applied epitaxially on top of plain silicon, or silicon carbide (Cree) which may or may not be ideally constructed, depending on skills of the manufacturer. Making blue LEDs was thought impossible, until a very clever Japanese fellow showed how to do it, and then UV. Red, amber, green, dead easy by comparison. Now we have all sorts of colours. White ones don’t exist, they are typically mainly a UV emitter with precisely tuned phosphor mix on top that converts UV to the high CRI white light we love. Making the phosphors is a closely guarded secret, making them last and be stable for thousands of hours even more so.

It’s dead clever.

Anyway, bottom line is that it’s tricky to run even tiny LEDs at very low currents consistently well. Thorfire got caught out when they changed between prototypes (working well) and what might have seemed like an identical alternative, according to datasheet, but now we know differently.

>Thorfire got caught out

“Trust, but verify”

[quote=Tom Tom]

Man that would have been nice to have!

[quote=Joey Adams]

Joey)!! How is it going? Good to see you man. :slight_smile:
You better make sure those batteries are charged buddy……. looks like your Q8(s) will be taking flight before too long…. headed straight at you.
Make sure you have your Eclipse Glasses handy too… your gonna need them. :wink:
:smiley:

:smiley:

Right click on your image…then “copy the link of the image”

Looks like the guy in the picture has his eye on the BLF Q8 too. :wink:

Just ordered my sixth Q8. The original group buy discount code I was PM’d still worked.

Lol, it also appears that his wife isn’t nearly as big of a flashlight fan as he is!

Got my Q8 today (30 minutes ago) and I LOVE it :smiley:

Mine is without bigger problems, some small but not that important.

button leds: one 50% brighter than other, but work - can live with it, but would like to fix that
driver screws: not stripped, look ok to me
tail pcb screws: one really stripped, 2 stripped but usable, one looks ok - don’t care, will replace them probably someday
emitters: 2 centered, 2 off centre? - looks like mistake when soldering? not really a problem to me
reflector: few dust pieces - nothing I care about
brass ring: almost no dirt
driver and tube contact: full circle - I would say perfect
outside: no scratches

Conclusion: nothing to complain about really, but I would like to fix button leds if possible

I need to remember all configuration button combinations some day, but ramping is so easy to use anyone can do it without problem. My dad got it the first time I explained.

Question:
Should button leds be on when light is on? Mine are on when light off, and off when light on.

Yes, they are off when the light is on. I wonder if there’s a switch in the UI that keeps them on all the time? I’d like them that way on mine.

You know… I think your right Joey!!! She looks more the Mini Mag Light type… :wink:
I think that guy is considering an upgrade……

I thought the guy was looking for a better lantern for his doghouse. . . .

nice that production has resumed……

any progress, or word on, or methodology, on those with defective lights? thank you.

My brothers light came in today, all looks good. No buggered up screws, the LEDS are both similar brightness. I’ll burn them in for him for 24 hours or so to prove them. I think all of the bad switch LEDs have failed in the first few hours. If I’m wrong could someone please let me know?

XXX-Man, actually two non properly flowed LEDs seem like an issue to me.
How handy are you?
Would be good to at least see how they are mounted, the cooling of the LEDs goes through the little DTP part of the ledboard.

Hang in there, solutions are being debated and we will wait for the first 500 to arrive to know exactly how many are affected.
BrianK check manual, if you can’t turn them on you have the issue too and need to be added to the OP list.
Please report

Yeah but for some reason 1024 is such a nice round number while 768 doesn’t do it for me :wink: