Results: Testing XM-L, MC-E, SST-50, and XP-G emitters **Updated**

129 posts / 0 new
Last post
mitro
Offline
Last seen: 1 year 5 months ago
Joined: 01/25/2011 - 11:58
Posts: 707
Location: Montgomery, IL USA

Match wrote:
(If anyone has an 18650 IMR and is willing to test this, I'd be very interested to hear the results).

With an IMR 18650 or an IMR 26650 I get right around 4.5A with the MF UF dropin. I figured they were DD. I keep saying I need to swap the NANJG on my triple XP-G with this UF driver.

I'm perfectly happy with an XM-L @ 2.8A. Actually for a P60 drop-in I think less would even be preferable. I have some A123 LiFePO4 cells that I've been playing with and they turn the MF UF drop-in into a very reasonable light. It would probably be too underdriven for most (1.4-1.5A) but I'm quite comfortable with it.

Match
Match's picture
Offline
Last seen: 2 years 1 month ago
Joined: 11/14/2010 - 11:57
Posts: 1488
Location: South Carolina, USA

DrJones wrote:

Great setup and great measurments, Match Smile

I compared it to the Cree datasheet specs, and it matches quite well up to 2.5A, then your values are a bit below theirs (3% at 3A). I guess that's due to their measurement method: If I remember correctly, they only power the LED for a small fraction of a second to avoid increasing the junction temperature. (Unfortunately I can't recall where I read that.)

This is quite possible.  For consistancy, all measurements were taken exactly 10 seconds after power on, which also allowed me to get the current dialled into +/- 1ma.  At higher power levels, it was quite apparant that output was dropping almost instantly due to, like you stated, junction temperature.  Considering the difference between the test heatsink and a standard flashlight, I feel these losses would be considerable at high power in normal practice. One of these days I'll direct mount a bare emitter to the test platform for comparison.

 

MunkyNutz
MunkyNutz's picture
Offline
Last seen: 1 year 3 months ago
Joined: 04/13/2011 - 13:29
Posts: 61
Location: KneeBrassKa, USA

SmileySmileySmiley

Foy
Foy's picture
Offline
Last seen: 3 years 1 month ago
Joined: 01/02/2011 - 17:56
Posts: 3009
Location: Las Vegas

Can someone please decipher arenat for me?

Foy

No referral links and nothing embedded . . . ever.

                      &nbsp

Don
Don's picture
Offline
Last seen: 1 year 2 weeks ago
Joined: 01/12/2010 - 16:32
Posts: 6617
Location: Scotland

Flashlight Foy wrote:

Can someone please decipher arenat for me?

'Tis in English.

 

There's two ways you can connect a resistor. Across the LED (in parallel) or between one contact of the LED and the equivalent contact on the battery or driver. (In series)

 

Hope that is slightly more intelligible.

 

And since i forgot to say so:

 

Thanks Match for this!

 

I reckon that was an enormous amount of work so thanks for doing this.

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

arenat
Offline
Last seen: 2 years 10 months ago
Joined: 11/22/2010 - 01:00
Posts: 364
Location: Argentina

Since my language skills are inexistent maybe posting what Match stated above some people can get it...

"The lumen difference for any torch or drop-in much above 3a woud be negligable outside a I.S.  Any perceived difference would be almost entirely based on the reflector/lens combo.  This is going to be my new wish from manufacturers...."Better xm-l reflectors, not more amps!"

 


devman
Offline
Last seen: 1 year 10 months ago
Joined: 04/27/2011 - 06:24
Posts: 825
Location: Hong Kong / Vancouver, Canada

Thanks Match!

...wait. wow...

I'm.. I'm.. actually satisfied with my current t6 dropin? no more lusting for higher current drivers, when 3A is more than good enough?

... whatever will I do now? Cry

(seriously, thanks.  You've laid that question to rest for good.  I gotta ask though, since those 80 stars were for work, what would you have done if you'd blown them? Pushed back the project, or did you over-order 'just in case'?)

JohnnyMac
JohnnyMac's picture
Offline
Last seen: 5 months 4 weeks ago
Joined: 04/12/2011 - 16:03
Posts: 8864
Location: Eastern PA

devman wrote:

Thanks Match!

...wait. wow...

I'm.. I'm.. actually satisfied with my current t6 dropin? no more lusting for higher current drivers, when 3A is more than good enough?

... whatever will I do now? Cry

Why, go with multi-xml emitter setups of course, silly! Silly
Match
Match's picture
Offline
Last seen: 2 years 1 month ago
Joined: 11/14/2010 - 11:57
Posts: 1488
Location: South Carolina, USA

devman wrote:

 

(... I gotta ask though, since those 80 stars were for work, what would you have done if you'd blown them? Pushed back the project, or did you over-order 'just in case'?)

First rule of business: Why buy one when you can get two at three times the price! (bonus points if you know the movie that's quoted from)

I already had a few extra.  After the first run and seeing no evidence of damage, I was content to try out some of the other 80 ordered.

devman
Offline
Last seen: 1 year 10 months ago
Joined: 04/27/2011 - 06:24
Posts: 825
Location: Hong Kong / Vancouver, Canada

JohnnyMac:  

Na.  I'd have to go the toilet-plunger route to do that right, and I'm not a big fan.  (and unlike match, I don't have access to large blocks of copper and a holesaw to make a svelte version practical)... so it's either go play in the knife forums, or start modding smaller torches.  We'll see which based on DX shipping times.

Match:

Contact (google remembered for me).  I remember being very disappointed by that movie at the time.  The opposite of disappointment is.. mmmm...  copper barstock... machine tools that aren't dremel...  drool...

Boaz
Boaz's picture
Offline
Last seen: 7 hours 26 min ago
Joined: 11/07/2010 - 09:31
Posts: 6468
Location: Birthplace of Aviation

First rule in government spending: why build one when you can have two at twice the price? Only, this one can be kept secret. Controlled by Americans, built by the Japanese subcontractors. Who, also, happen to be, recently acquired, wholly-owned subsidiaries...
contact ?? I would have  guessed ironman or lord of war

καὶ τὸ φῶς ἐν τῇ σκοτίᾳ φαίνει καὶ ἡ σκοτία αὐτὸ οὐ κατέλαβεν

agenthex
agenthex's picture
Offline
Last seen: 4 years 6 months ago
Joined: 07/14/2010 - 04:49
Posts: 3070
Location: Merica

Match wrote:

 No, not off-topic at all.  In fact, this brings up a good point.  After testing I took out my MF UF 3 mode drop-in and measured the current it was drawing off the battery ( measured without host.  Used ampmeter leads to make negative contact).  I measured @4.2a on high with a fresh battery.  Then I hooked the same battery directly to an xm-l (DD) and took another reading.  Guess what it read? @4.2a!  

From what I've observed, with these new "xm-l drivers" is that they are DD in high mode and there is no current regulation happening at all.  

I feel any current difference at high end is largely due to the individual cell.  With that in mind, I would highly advice against running a low  internal resistance cell like an IMR due to the high potential for excessive current. (If anyone has an 18650 IMR and is willing to test this, I'd be very interested to hear the results).



If you have a shot of the driver board, or just the part # off the chips on it, you can tell how it works.

Reading this makes you smarter: http://lesswrong.com/

agenthex
agenthex's picture
Offline
Last seen: 4 years 6 months ago
Joined: 07/14/2010 - 04:49
Posts: 3070
Location: Merica

oldbobk wrote:

arenat,

       Breadboard it up, take some readings. This is my last post on this issue.

                                                                                                                    Bob K

quote=arenat]

Oldbobk,

 

"Run in series, you have to have a resistor that will run the wattage of the light"

I understand perfectly what you say but just because the above sentence is incorrect what you get is the opposite. In parallel with the emitter the resistor must be much more powerful than one in  series.

[/quote]

He is correct in that this is in error:

"Run in series, you have to have a resistor that will run the wattage of the light"

It doesn't because the resistor doesn't have to have the same voltage across it as led Vf.

However, your main problem is that putting a resistor in parallel will lower the equivalent "resistence" and therefore not really lower the current much through the emitter. IOW, you'll mostly just heat up that resistor.

Reading this makes you smarter: http://lesswrong.com/

Budgeteer
Budgeteer's picture
Offline
Last seen: 4 years 7 months ago
Joined: 08/24/2010 - 02:19
Posts: 3087
Location: Slovenia (EU)

Thank's Match! So the general consensus is the XM-L should be driven between 2.4-3.2A for optimal results current/lumen/heat ratio.

I find the KD 2.8A driver the best for the job even if it works at 2.8A for a dozen min or more then drops gradually as Vbatt drops.

We really need some decent buck/boost drivers for cheap!

kragmutt wrote:

They're gonna send you a green redcat with a black LED.

ledoman
Offline
Last seen: 3 days 21 hours ago
Joined: 09/25/2010 - 06:27
Posts: 892
Location: Slovenia (EU)

Budgeteer wrote:
We really need some decent buck/boost drivers for cheap!

And for higher voltages 8.4V with few memory modes also!

fishinfool
fishinfool's picture
Offline
Last seen: 1 year 10 months ago
Joined: 03/09/2010 - 00:30
Posts: 4342
Location: Hilo, Hawaii

Good job as usual Match!  

 

Don wrote:

"But as I said long ago, you are more likely to be killed by a dead fish dropped by a seagull in the Sahara Desert than by a lithium ion

Piers
Offline
Last seen: 2 years 3 months ago
Joined: 01/18/2011 - 20:31
Posts: 894
Location: Bolton, UK

Awesome job Match! I think that pretty definitively settles all that nonsense Silly

Langcjl
Langcjl's picture
Offline
Last seen: 1 month 1 week ago
Joined: 03/05/2011 - 05:36
Posts: 2162
Location: Wisconsin USA

Page 13 for this? Never!

Piers said " ....but who wants enough light, when you have the option for far too much "

bao123
Offline
Last seen: 6 years 10 months ago
Joined: 06/06/2011 - 02:26
Posts: 11
Location: PA

Good work Match.  There were similar tests by someone on CPF.  People definitely need to pay attention to this thread.  Needs a sticky to get the word out.  No reason to excessively overdrive XM-Ls.  Maybe a catchy title like the CPF one.  Something like "Overdriving XM-Ls diminishing returns and loss"

RedForest UK
RedForest UK's picture
Offline
Last seen: 2 months 3 weeks ago
Joined: 06/06/2011 - 11:27
Posts: 1049

I'd just like to point out that tailcap current is normally not what actually even goes into the driver unless it's a twisty light. Most tailcaps offer significant resistance, this has less of an effect on regulated drivers but with the Manafont 3 mode it has quite a big impact. My L2p tailcap consistently lowers the actual current by about 0.5A from what I read over the tail cap but not through the actual tail switch. The basic L2 switch lowers current a little bit more again.

 

So, if you read 3.6A on the tail while using the DD manafont drop-in, once you put the tailcap back on the led will probably only see 3.1A of it.

orbital
orbital's picture
Offline
Last seen: 5 years 8 months ago
Joined: 06/15/2011 - 17:39
Posts: 3
Location: Great Lakes

+

 

Great information in this thread, I'v wondered when XM-L would simply start to overrev.

3.25A looks to be a realistic ceiling.

 

I registered because of this thread,..thanksSmile

JohnnyMac
JohnnyMac's picture
Offline
Last seen: 5 months 4 weeks ago
Joined: 04/12/2011 - 16:03
Posts: 8864
Location: Eastern PA

Welcome to BLF, Orbital!

okwchin
okwchin's picture
Offline
Last seen: 1 year 4 months ago
Joined: 01/07/2011 - 04:41
Posts: 1144
Location: Australia

Regarding resistors in series vs parallel

 

In a normal situation - lets call it a DD circuit.

Series - will add a resistance to the whole circuit, reducing overall current draw. Since current passing through each component in the series circuit is the same, the LED will be receiving reduced current draw.

Power in watts is the current multiplied by the voltage drop across each component. The emitter will drop between 3-4V depending on what it is, and what current flows, the resistor can drop any voltage depending on its value.

 

Parallel - The resistor is effectively independent of the LED because current can flow both "circuits"; the LED or the resistor. Remembering that current draw is determined by the resistance of each circuit, the LED will draw its own current, the resistor will draw its own current and will not affect each other.

With an ideal power supply, the resistor will simply draw current, and make heat. The LED will also do its own thing, as if there was no resistor. So essentially all thats happening is that more power is being drawn

 

This changes however in a Current Controlled circuit. If your circuit is able to run in regulation, and has enough voltage excess, the 'better' way to reduce power to the emitter is to put a resistor in parallel with the emitter, because the total current flow is limited to X amps. A resistor in parallel will in this case be dividing the current. 

A resistor in series will be increasing the total resistance (voltage drop) of the circuit if driven by a constant current driver, and will increase the power draw at the battery end to deliver the same current output. So in that case we will be pushing the same current through the emitter and the resistor. We will effectively just be creating more heat in the resistor, with no reduction in current to the emitter.

 

The only reason why this is confusing is because we are using current controlled circuits, it reverses the ideas sometimes. This is an example where it can be sometimes counterintuitive. Like for example, when I want to measure the current output of these drivers, I just select the amps setting and short out the driver (only TRUE CC drivers) with the DMM. This short has a very low resistance and normally lets lots of current through, but in a TRUE CC driver it will effectively be drawing almost no power to maintain those 3A. If the driver is not a true CC driver, it will let more amps through and possibly die..

On the other hand open circuits are destructive to TRUE CC boost drivers, with the boost voltage potentially rising very high and killing itself.

"like everyone else - I’m looking for my next “last” flashlight" -  ohnonothimagain

okwchin
okwchin's picture
Offline
Last seen: 1 year 4 months ago
Joined: 01/07/2011 - 04:41
Posts: 1144
Location: Australia

And thanks match for the datapoints! Invaluable data!

 

And thanks for the linear scale graph brted - looks beautiful how all those datapoints line up soo well, thanks to match

"like everyone else - I’m looking for my next “last” flashlight" -  ohnonothimagain

Match
Match's picture
Offline
Last seen: 2 years 1 month ago
Joined: 11/14/2010 - 11:57
Posts: 1488
Location: South Carolina, USA

First post now updated to reflect testing of the cree MC-E emitter.  Test procedure was performed exactly like the xm-l.

Post is now sticky'd for easier reference.

p.s. - Welcome Orbital!  Glad to be of assistance.

Match
Match's picture
Offline
Last seen: 2 years 1 month ago
Joined: 11/14/2010 - 11:57
Posts: 1488
Location: South Carolina, USA

Folks,

  Testing complete and up in the first post for the SST-50.  Thanks again goes to BobK for providing the emitters for testing.  From the results it's clear that the SST-50 is still alive and kicking in applications above 4 amps.

JohnnyMac
JohnnyMac's picture
Offline
Last seen: 5 months 4 weeks ago
Joined: 04/12/2011 - 16:03
Posts: 8864
Location: Eastern PA

Great work, Match! I really appreciate the effort as do, I'm sure, we all!

Davx
Davx's picture
Offline
Last seen: 2 years 2 months ago
Joined: 03/17/2011 - 20:29
Posts: 910
Location: Italy

Great work. Very useful also for mod with hard driven emitter. Thanks Match!

"There are always new jobs, women, and apartments......there is only ONE BLF." - Chicago X (27/03/2012)

orbital
orbital's picture
Offline
Last seen: 5 years 8 months ago
Joined: 06/15/2011 - 17:39
Posts: 3
Location: Great Lakes

Match wrote:

First post now updated to reflect testing of the cree MC-E emitter.  Test procedure was performed exactly like the xm-l.

Post is now sticky'd for easier reference.

p.s. - Welcome Orbital!  Glad to be of assistance.

+

thanks Match  Cool

vinhnguyen54
Offline
Last seen: 2 years 3 months ago
Joined: 06/11/2011 - 01:22
Posts: 123
Location: Washington

Will there be a test for SST90?! Thank!

Pages