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

BLF Q8 Group buy sale statistics, Using UTC+2 time.

Date -> Preorders
7. Sept 02.00 GB Started
7. Sept 20:40 -> 500
7. Sept 23:50 -> 742
8. Sept 04:35 -> 931
8. Sept 07:47 -> 993
8. Sept 10:24 -> 1024 — Yes exactly at that time, I double checked!
8. Sept 21:42 -> 1106
9. Sept 03:58 -> 1143
9. Sept 22:20 -> 1202
10. Sept 0428 -> 1212
11. Sept 22:32 -> 1320
12. Sept 22:11 -> 1359
13. Sept 20:45 -> 1389
14. Sept 2042 -> 1422
15. Sept 20:20 -> 1458
16. Sept 10:00 -> 1493
16. Sept 19:40 -> 1523
25. Sept 05:42 -> 1671
26. Sept 12:32 -> 1706
26. Sept 19:59 -> 1726
27. Sept 10:57 -> 1764
27. Sept 16:40 -> 1775

The total parasitic drain for the Q8 is 135uA. The LEDs drain 113uA and the driver drains 22uA.

Amplificus swapped the 15K switch resistor to a 10K resistor and that made his switch lights start working again. Then he measured his parasitic drain again and got a total of 155uA.

I was in the second 500, but my estimated shipping date is the 10th of October. I think I’ve seen someone with a better date…

Its much more complicated, the LEDs are being operated on the knee of a very rapidly reducing curve, not a nice flat region (datasheet Vf). A few microamps difference could make all the difference between lighting up nicely or not. Most of the microamps will not be going into making light, at these low levels, the majority will just be leaking through the compound semiconductors in the LED, to no effect. It is far from a linear relationship between current and light output at these infinitesimal levels, and this is on the ragged edge.

Edit: and the actual “Vf” will be varying hugely with tiny changes of current at these low levels. Amazing it can work so well with just a series resistor, it is absolutely not just a simplistic Vf=x, current = y, thus therefore voltage drop across resistor = Vbatt (variable) -(Vf at current =y), apply Ohms law, resistor defined, whack it in. Oh no.

What time coordinates are those ? China is at least 12 hours ahead of US east coast (I think, may have it an hour or two wrong).

Maybe correct it to GMT (or UTC if you must), or back-calculate to Banggood China time (not sure what zone they are in, I think they stick to standard)

Nevertheless the gist suggests to me I was a bit late with my first order.

PS: Wim sent me the codes 2 hours before they went live “Codes start working on Sep, 7th 10:00 am (UTC+8).”

RapidLux nice
Lol at 1024

Estimated ship dates are like the warnings from Sony and LG that say their 18650 batteries should not be used except in battery packs; best totally ignored.

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!