Provocative consideration on SF E2 efficiency

Klaus

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The E2HA I got around christmas is thanks to SFs customer service back in a working state - have been playing around and moding some other lights to get closer to the E2 beam brightness/quality & size/usability.

(Best succes sofar in overall size/usability & brightness/beam is the DB 4AAA moded to 4xAAA serial operation using 4 Sanyo AAA 700ma NiMhs with DB/WA 6AA bulb slightly overdriven and WrightRight on the lens - this comes pretty close to the E2 at way lower runtime cost - next try will be the TEC40 - and yes - I need to supply beam shots)

And here the issue starts:

Other lights in the 60 lumens ball park do consume quite less power than the E2.

Looking at Brocks site and redoing the calculaton the E2 uses around 5W to get 60 lumens - (5V at 1A) - this is some quite low 12lumen/Watt efficiency - the best halogens and Xenons in the 5~6V area are approaching 20lumens/Watt.

Incidentally the above mentioned 4AAA is consuming around 3W as opposed to the E2s 5W while admittedly the E2 is brighter and has a better beam still - (and the E2 is smaller and neater) - but nowhere near what the difference between 3W and 5W power usage would make you expect - its really very close - and this 3W 4AAA is using ever-so-cheap rechargeables and the 5W E2 is using ever-so-expensive Lithium 123s - comparing the 1 hour runtime/cost its just ridiculous.

This makes we wonder about the efficiency of the E2 LA and lets me wonder about if I am comparing apples to oranges here and/or if something in my comparison/math is totally off - or if SF might be better doing some re-engineering of the LA assemblies to get higher runtime or oupout out of the units.

My provocative calculation would bring me to the conclusion (given my math is right) that if SF would reach the typical efficiency of the best Halogen / Xenon bulbs at 20 lumens /Watt instead of the 12lu/W the E2 could have either 100 lumen output at its 75 min runtime or would have a runtime of 125 minutes at 60 lumens - this calc is theoretical but I think you get the idea.

Maybe one of our SF specialists or master PK himself might be posting some comment on this ? I really don´t want to bash the E2 SF or SF in general and I think the E2 is one great little light - but having this quite good success in trying to have E2-style output at much lower runtime cost made me think SF could do better in that area too.

Klaus
 

lightlover

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Klaus,

Klaus Klaus Klaus !
Klaus Klaus Klaus Klaus Klaus !!

Do you want to end up in the same sad state as Brightnorm ?
Poor guy was cast into the wilderness with only a broken-lensed cheapo, and a few leaking Carbon-Zincs to comfort him.

Actually, I don't know what the figures really mean in terms of relevance to the E2's efficiency. From member PK's posts, it seems that he is not unaware of issues relating to torch efficiencies.
Could it be that filament reliability is a factor in the calculations ?

lightlover
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Size15's

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If SureFire's E2 Lamp is pretty much the longest runtime, best quality beam of all 2 cell 123A lights, and that's what SureFire have developed since the P60 and no other company can produce such a beam with longer runtime since they have started copying SureFire.

My opinion is that if SureFire could have released a better lamp, they would have.

Al
 

Klaus

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Hi Jahn,

yes I´m aware of the risk
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but remmeber I still have my 1500 lumen lightsaber ™ to defend myself against attacks
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just look at my sig
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Regarding reliability - good point - the only available numbers on that is the half-life of the bulb which in both cases (SF MN02 and high-efficiency Halogen/Xenon) is around 20-30 hours - bulbs designed for longer life (i.e. miner bulbs) do have lower efficiency numbers while giving hundreds of hours lifespan - IMO this isn´t the case for the bulbs I compared.

Where did PK talk about possible efficiency shortcomings ?

Klaus

Al - agree on E2(e) being the longest runtime / best beam combo for 2 x 123 lights - but more output or longer runtime based on efficiency improvements wouldn´t hurt though. Just curious about that 12lm/W vs 20lm/W comparison and as I wrote I´m not shure if I compare apples to oranges or if there really is room for improvement - or if the 12lu/W (if accurate) is the willingly designed-in trade-off for other features. I think PK might be the right person to comment.
 

lightlover

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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Klaus:
Hi Jahn,

... Where did PK talk about possible efficiency shortcomings ?

Klaus
<HR></BLOCKQUOTE>

Ummm, well nowhere, as far as I recall ......
But PK has posted some very educational stuff altogether.

I was just making the point that the issues you've raised were probably considered by SF and their Leading Engineer.
As I read your post, it occurred to me as a possible factor which might explain the relative lack of efficiency you are positing.

Jahn
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Klaus

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Jahn,

I hope tear and feathers are not ready yet - I re-read your post - you are right - and I think too that PK is aware of efficiency and as as I wrote there might be some trade-off I´m not aware of (yet) - and again - I´m still not shure if my math is right.

Where did PK post about such stuff - on SFDB or CPF ? Do you remember the thread or approximate timing ?

How´s life these days in your galaxy ?

THX

Klaus
 

lightlover

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Oh, life's not too bad Klaus.

Btw, we're cross-posting.

Let me just say repent now !!
Oh, it's too late for that, sorry ......

(I'll still speak to you, even if nobody else will.)

lightlover
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pwell

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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Klaus:

(Best succes sofar in overall size/usability & brightness/beam is the DB 4AAA moded to 4xAAA serial operation using 4 Sanyo AAA 700ma NiMhs with DB/WA 6AA bulb slightly overdriven and WrightRight on the lens - this comes pretty close to the E2 at way lower runtime cost
<HR></BLOCKQUOTE>

Klaus, we must be on the same brainwave or something. Last night I was also trying to think of different sized NiCD combinations that could be used instead of two CR123s. Couldn't come up with anything though. It would just be sweet if they brought out a 6V NiCD/NiMH the size of two CR123s.

Cheers
 

pwell

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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Klaus:
...but remmeber I still have my 1500 lumen lightsaber ™ to defend myself against attacks
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<HR></BLOCKQUOTE>

And you are a pretty safe distance from SF headquarters. :)

Hows the lightsaber? I've been looking for recent posts. Mine is done, just have to ad a charging plug.
 

Klaus

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Hi Sean,

still not fallen off the earth down-under ?

On the project light - William is working on the tooling still - the switch looks fantastic - he is working on the heat-shielding right now. I´m still working on the smart charger bringing it up to 3,5A charging current to have a 1hour fastcharge - so my new name is IC slaughterhouse champ now as I burned through too much ICs and transistors in the meantime
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You are running the 50W IRC
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? This should be round 2000 lumens or so
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And yes - having NiCd/NiMh replacements for 123s is nice - there were posts lately on that NiMh 123s from the UK and PK from SF is also working on 3,6V LiIon 123-replacements for the new Digital SFs - still this is very new territory and quite expensive right now - using those 4AAAs is quite cheaper for the time being - though the body of the DB 4AAA is larger than would be needed to accomodate 4AAAs - maybe I should look into that PT Rage (4AAA) and try that one too ?

CU

Klaus
 

Klaus

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recercare - you are certainly right - actually the reason why I use the 6AA bulb in the 4xAA & AAA NiMh configurations.

But my point of 20lumens / Watt wasn´t targeted at the WA bulbs but for high-quality Halogen & Xenon bulbs in general.

Klaus
 

recercare

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The bulbs used in the Energizer Double Barrels are first class. However, I've found something confusing, and very unfortunate. It's not Welch Allyn's fault. You have to blame Energizer.

The specifications for Welch Allyn bulb in 6AA read 49 lumens at 4.2V. However in a DB 6AA you can expect only 3.6V, so you have to rerate the lamp. The same goes for the DB 8AA. According to Welch Allyn the bulb has more than 80 lumen output if run at 5.5V. In a DB 8AA you can expect only 4.8V, so the actual lumen output is approx 60.

So...Energizer has not bothered to measure actual lumen from their Double Barrels, they've just copied the lumenratings from Welch Allyn even though these bulbs are undervolted in the DB flashlights. Very misleading indeed.
 

Klaus

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Aragorn - who said I have a problem ?

Might I suggest YOU resolve that problem of not supplying any data on those NiMh 123´s - you didn´t posted any price, capacity or runtime data which is IMO important.

When I emailed the guys months ago when the issue was first brought up here and I was reluctant to spent approx. 100 bucks on charger and 2 cells ! the guys resonse on my question for capacity and voltage was

QUOTE:

The voltage and capacity rating is not very helpful in determining their suitability for given products - one needs to "suck it and see."

ENDQUOTE:

So I guess you "sucked and saw" ? Such bad results you don´t want to post about or did I miss something ?

Respectfully

Klaus
 

Graham

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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Aragorn:
how about if i ship the light cannon to you and you can blast yourself and send it right back?
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<HR></BLOCKQUOTE>

Hey, you can ship your light cannon to me, and I'll blast myself with it..but I can't guarantee I'll send it back..
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Ahh, to have a light cannon of my very own..
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Graham
 

pk

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Klaus,

Let's try to locate some possible in-efficient design elements in flashlights.
1) Reflector
2) Lens
3) Resistance buildup form electrical path.
4) Switch resistance
5) Lamp/Bulb
6) Battery
These are all important factors for building efficient flashlights design.

However, since you just want to talk about Lamp/Bulb assembly.
Let me share a little detail about the SF Lumen Rating System.
I have started my SF Beast HID project with a 3100 Lumen FACTORY RATED bulb,
And I was only able to get 2000 Lumen out-of–window when I packaged with our reflector and Pyrex lens.
So, we rated the Beast for 2000 Lumens.
Please keep in mind that all SF Lumen ratings are actual light output from our flashlights.
Not the Lumen rating of bulb from bulb manufacturers.

I hope you can understand our practical rating system.


Aragorn,

I'm going to tell your mum on you TOO.
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Best Regards,
pk
 

brightnorm

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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by pk:
...So, we rated the Beast for 2000 Lumens.
Please keep in mind that all SF Lumen ratings are actual light output from our flashlights.
Not the Lumen rating of bulb from bulb manufacturers.
<HR></BLOCKQUOTE>

PK,

Engineers are often stereotyped as nerdy number crunchers without an imaginative bone in their bodies. I know so many exceptions from my own experience that the injustice of such a sweeping generalization is very clear.

I've long admired the beauty of your designs as well as their functionality, and I'm curious to know how they evolve. Do you start with a technical (engineering) goal which dictates the size/shape/ergonomics of the piece, or the other way around. Or perhaps something entirely different? I can think of several variations.

It seems to me that there must be an
"inspirational" element as well, since all creators rely at least partly on inspiration, the sources of which are often unknowable.

On a more mundane note: Can you please tell me the actual burn time and weight of the Beast.

I'm sure the demands on your time must be fierce, but I would be most appreciative if you have a chance to respond.

Best regards,
Brightnorm
 

lightlover

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Ah, Brightnorm,
how polite of expression you are.
[ Shame that that can't be said about a certain young member posting in this topic ... ]
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As to your request - I'm sure we'll get a response from *The Artist*. (Formerly Known as PK.)
Why, surely it must need a man with a Heart of Stone to refuse such an appeal !!!

lightlover
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