[Interest & Feasibility Check] Sofirn SP10S "BLF edition" with Andúril

486 posts / 0 new
Last post
Melez
Offline
Last seen: 6 days 18 hours ago
Joined: 10/03/2016 - 17:58
Posts: 31
Location: Colorado
djozz wrote:
I think that a 2A drive limit on a 14500 is sensible, it gives you around 700 lumen output which is ample for a small light and will already need a stepdown after a few minutes because of the heat. Also, most 14500 cells will not even deliver more than 2A for any length of time (but depending on led voltage).

I wonder what a sensible driver limit would be? If they used the LH351D, the high CRI supposedly gets ~360-400lm@1050mA(bin dependent), that’d probably end up around 640-870lm@3v/2A. Driving it at 3v/1.5A would get ~485-690lm and keep load down on 14500. An eneloop can push what, 3A@1.2-1.5v? boosted to 3V~1.5A sounds doable ish.

kikkoman
kikkoman's picture
Offline
Last seen: 3 months 3 days ago
Joined: 05/03/2012 - 08:08
Posts: 219
Location: Austria
Melez wrote:
An eneloop can push what, 3A@1.2-1.5v? boosted to 3V~1.5A sounds doable ish.

Unfortunately it’s a bit more complicated.
Let’s have a look at the images below.

At higher currents, the internal resistance becomes noticeable in that the output voltage instantly drops considerably. (If you have a Li-ion and a NiMH with the same IR, the NiMH drops a much bigger fraction of its V_out at a given current, where it counts)
Then there’s losses everywhere – springs, contacts, inductors, semiconductors etc etc – and we’re losing even more precious mVs.

The third graph is from this very chip – it’s as good as it gets – and we can see that at these voltages we’re already dipping into VERY inefficient territory @1A out – and now, if you want to keep this 1A out up, you pull 6 amps from the poor battery. —> lower voltage, even higher losses, even lower Eff, in short – everything shits the bed at once.

It’s just the way it is. ¯\_(ツ)_/¯

(Oh and it’s much much worse with Alkalines.)

That’s also the reason why the lights with the highest claimed output on AA/NiMH don’t keep that output up for long.

Melez
Offline
Last seen: 6 days 18 hours ago
Joined: 10/03/2016 - 17:58
Posts: 31
Location: Colorado

Thanks for that explanation kikkoman!
Efficiency really just falls screaming off a cliff in the third graph. I guess it entirely makes sense, boosting voltage is so much more difficult with a high difference between in/out.
So if i understand correctly then we’d be converting 1.5v->3.3v in ideal condtions we’d need 2.2A at 100% efficiency to get 1Aout, but factoring in driver dipping below 50% we’d need 4.4A, then toss in rando V loss for another 33% to end up in the 6A range?
Poor battery holy crap.

Also probably explains why Zebralights are so much more efficient than Armyteks by only boosting to 6v for their emitters instead of boosting all the way to 12v.

hank
hank's picture
Offline
Last seen: 18 hours 51 min ago
Joined: 09/04/2011 - 21:52
Posts: 8151
Location: Berkeley, California

Put a sliding cover on the side button to prevent pocket light. They’re being made for cell phones:

https://www.google.com/search?client=firefox-b-1-d&q=phone+button+slide+...

Tenshi0
Offline
Last seen: 15 hours 33 min ago
Joined: 02/21/2019 - 07:45
Posts: 11

Extremely interested!

kikkoman
kikkoman's picture
Offline
Last seen: 3 months 3 days ago
Joined: 05/03/2012 - 08:08
Posts: 219
Location: Austria
Melez wrote:
So if i understand correctly then we’d be converting 1.5v->3.3v in ideal condtions we’d need 2.2A at 100% efficiency to get 1Aout, but factoring in driver dipping below 50% we’d need 4.4A, then toss in rando V loss for another 33% to end up in the 6A range?

My back-of-the head calculation was: 1.1V (already under load! +losses) to 3V@1A = 3A in —> Eff. dipping below 50% —> 6A in. (And then further V_in drop etc.)
This particular converter shuts down at 4A I_sw, that’s where it ends.

When the efficiency curve is that steep it doesn’t make much sense to make detailed calculations anyway. It’s a dynamic system, and it just goes bad, fast. One problem exacerbates the other and vice versa. That’s the bottom line.

You could, in theory, run 2 switchers in parallel and share the load, but then the battery still remains the weak link.

—————————————————-

With all this in mind, what’s a reasonable output?
I think the sweet spot is around 200 lumen, a good balance between output and runtime. Seems to be what most AA lights have settled at. (Although some still step down from that, for some reason.)
Keep in mind, 90CRI has a bit of an impact too.

wyatt1209
Offline
Last seen: 9 hours 1 min ago
Joined: 11/22/2018 - 13:25
Posts: 34

Interested

Wratz
Offline
Last seen: 16 hours 1 min ago
Joined: 04/12/2019 - 20:52
Posts: 23
Location: Texas

This would be awesome!

Wratz
Offline
Last seen: 16 hours 1 min ago
Joined: 04/12/2019 - 20:52
Posts: 23
Location: Texas

hank wrote:
Put a sliding cover on the side button to prevent pocket light. They’re being made for cell phones:

https://www.google.com/search?client=firefox-b-1-d&q=phone+button+slide+...

Correction

This is what would be awesome!

Zunkted
Offline
Last seen: 1 week 4 days ago
Joined: 04/11/2019 - 20:18
Posts: 31

I’m interested!

Teamrayray
Offline
Last seen: 4 months 2 days ago
Joined: 05/17/2019 - 22:45
Posts: 1
Location: Ohio

Interested

oldlumen2011
Offline
Last seen: 4 months 3 weeks ago
Joined: 05/17/2019 - 03:29
Posts: 3
Location: USA, Michigan
Thumbs Up
aswang
Offline
Last seen: 4 hours 38 min ago
Joined: 07/17/2018 - 07:53
Posts: 193
Location: Philippines

This is turning out great. Now I’m definitely interested in 4 or 5 of these especially if the price is not so far off the SP10B. Also interested in a couple of drivers if they become available for purchase.

Kiltan
Offline
Last seen: 1 week 3 days ago
Joined: 05/18/2019 - 04:02
Posts: 7

Interested.

rost333
rost333's picture
Offline
Last seen: 20 hours 59 min ago
Joined: 08/08/2018 - 10:01
Posts: 341
hank wrote:
Put a sliding cover on the side button to prevent pocket light

Are you talking about something like webcam cover?

or more like remote control cover?

The second design would fit more this new 2AA flashlight from Sofirn Wink

gmjuras
Offline
Last seen: 4 months 2 weeks ago
Joined: 02/14/2019 - 16:52
Posts: 4
Location: POLAND

Interested

i42dk
i42dk's picture
Offline
Last seen: 15 hours 52 min ago
Joined: 08/30/2017 - 05:35
Posts: 192
Location: Denmark

uuuh interested Love

kikkoman
kikkoman's picture
Offline
Last seen: 3 months 3 days ago
Joined: 05/03/2012 - 08:08
Posts: 219
Location: Austria
Lexel wrote:
Attiny MCU and AA Voltage wont work without a separate boost powering the MCU, which would make likely a way too high standby drain not sure how the original driver handles this

Look ma, no hands separate boost converter

1.4V in, this is standby

View post on imgur.com
gotang
Offline
Last seen: 1 day 18 hours ago
Joined: 01/29/2019 - 16:15
Posts: 8

Anduril on an AA light? If that happens, sign me up for several! I guess I’d better keep a closer eye on this thread!

Ulrich
Offline
Last seen: 2 days 11 min ago
Joined: 01/06/2017 - 14:53
Posts: 13
Location: Frankfurt, Germany

Interested.

The best light is the one in your pocket when you need some.

F.i.l.a.s
F.i.l.a.s's picture
Offline
Last seen: 2 hours 43 min ago
Joined: 11/22/2015 - 20:10
Posts: 124
Location: Prague

Nice project :). Interested

2Ace
Offline
Last seen: 12 hours 23 min ago
Joined: 05/03/2015 - 14:56
Posts: 49

Interested

terranaut
Offline
Last seen: 3 months 3 weeks ago
Joined: 09/04/2014 - 19:30
Posts: 10
Location: wpb, florida

interested

hank
hank's picture
Offline
Last seen: 18 hours 51 min ago
Joined: 09/04/2011 - 21:52
Posts: 8151
Location: Berkeley, California

>sliding cover

either kind, whatever’s available that could be adapted without reinventing the wheel.
Thanks to Rost333 above, for finding those examples.

Here’s another
https://www.aliexpress.com/item/32898609281.html

M78
Offline
Last seen: 12 hours 2 min ago
Joined: 01/06/2013 - 23:31
Posts: 283
Location: usa

Interested

Man Without Shadow
Man Without Shadow's picture
Offline
Last seen: 1 hour 54 min ago
Joined: 02/20/2017 - 18:17
Posts: 437
Location: Wisconsin

interested

When I'm spending mony foolishly, I like to do it wi$ely...

I have all the flashlights I need, but not as many as I want...

 

FrankFlash
FrankFlash's picture
Offline
Last seen: 1 day 44 min ago
Joined: 02/09/2014 - 11:31
Posts: 11
Location: South Africa

An AA-size flashlight with Anduril would be great.
I would definitely prefer high efficiency over high lumen output.
Regards Frank

Duke
Offline
Last seen: 17 hours 15 min ago
Joined: 08/11/2015 - 10:52
Posts: 93
Location: Germany

Interested!

Unheard
Offline
Last seen: 5 hours 21 min ago
Joined: 01/16/2019 - 11:38
Posts: 255
Location: Germany

interested

nordlicht
Offline
Last seen: 1 month 14 hours ago
Joined: 07/27/2017 - 10:28
Posts: 16

Interested!

Pages