Led Lensers
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Egsise
Banned
No I don't mean SSC P7, I mean old Led lenser P7 throws better than the new Led lenser P7.
Lux readings and beamshots:
http://www.candlepowerforums.com/vb/showthread.php?t=238619
Lux readings and beamshots:
http://www.candlepowerforums.com/vb/showthread.php?t=238619
McAllan
Enlightened
Ah, thanks for clarification. Wasn't aware that there was more than one version.
Egsise
Banned
The version that I tested was version 3.1 according the manual.
No I don't mean SSC P7, I mean old Led lenser P7 throws better than the new Led lenser P7.
Lux readings and beamshots:
http://www.candlepowerforums.com/vb/...d.php?t=238619
No, I do not believe that that is true. I think that the reviewer didn't fully tighten the head of both the lights. LL is trying to compete with the (debatably) more technologically advanced brands Fenix, Olight, Quark, and the rest, therefore I doubt they would actually reduce the output.
Lux readings and beamshots:
http://www.candlepowerforums.com/vb/...d.php?t=238619
No, I do not believe that that is true. I think that the reviewer didn't fully tighten the head of both the lights. LL is trying to compete with the (debatably) more technologically advanced brands Fenix, Olight, Quark, and the rest, therefore I doubt they would actually reduce the output.
Egsise
Banned
The output increases, but the focus doesn't seem to be as tight as with the old versions.
JaguarDave-in-Oz
Enlightened
that certainly right in terms of the few new versions ones I've seen beamshoots of. Those ones were not as tightly focussed as my old version was even before I "tuned" it.
McAllan
Enlightened
Re: Led Lensers - Picture of M14 driver
Hi
You're probably just as curious as I am. So to satisfy my curiosity I took a look at the driver in the M14. And to satisfy yours I took some pictures of it.
So here goes:
From the positive side of the battery one lead goes to the driver and the other to the LED.
So the LED is driven by controlling the negative connection.
A close up on the driver.
Yeah I know. Now we'll a bunch of whiners crying that there's no inductor which means regulation is linear.
True - BUT let's do a bit of calculating. Nominal voltage of 4 NiMH is 4.8 v. Nominal voltage of 1 full driven (1 A) LED is 3.7 v. The voltage difference is burnt of by heat in the driver:
3.7 / 4.8 = ~77 % efficiency.
That's actually pretty good and competes quite well with most inductor based ones.
And we haven't even taken into account that the LED is pulsed and the pulses might even be more than 1 A which only raises efficiency by an unknown amount.
The bad news is however that with primary lithiums a bit too much power may be dissipated in the driver. Haven't tried that since I don't got any and I'm a big fan of (LSD) NiMH (almost guilt free lumens 😉)
Haven't taken a further look at the had assembly so can't comment that much. But a look into the barrel from the battery side suggests fine cooling of the LED. The M14 doesn't get very hot with prolonged use (tried running it for 30 min) at least not with NiMH. NiMH doesn't heat very much at 1 amp so a great part of the heat is coming from the LED. And the size of the M14 body means a large area for dissipation. And the black color helps too (yes that's true!).
Hi
You're probably just as curious as I am. So to satisfy my curiosity I took a look at the driver in the M14. And to satisfy yours I took some pictures of it.
So here goes:
From the positive side of the battery one lead goes to the driver and the other to the LED.
So the LED is driven by controlling the negative connection.
A close up on the driver.
Yeah I know. Now we'll a bunch of whiners crying that there's no inductor which means regulation is linear.
True - BUT let's do a bit of calculating. Nominal voltage of 4 NiMH is 4.8 v. Nominal voltage of 1 full driven (1 A) LED is 3.7 v. The voltage difference is burnt of by heat in the driver:
3.7 / 4.8 = ~77 % efficiency.
That's actually pretty good and competes quite well with most inductor based ones.
And we haven't even taken into account that the LED is pulsed and the pulses might even be more than 1 A which only raises efficiency by an unknown amount.
The bad news is however that with primary lithiums a bit too much power may be dissipated in the driver. Haven't tried that since I don't got any and I'm a big fan of (LSD) NiMH (almost guilt free lumens 😉)
Haven't taken a further look at the had assembly so can't comment that much. But a look into the barrel from the battery side suggests fine cooling of the LED. The M14 doesn't get very hot with prolonged use (tried running it for 30 min) at least not with NiMH. NiMH doesn't heat very much at 1 amp so a great part of the heat is coming from the LED. And the size of the M14 body means a large area for dissipation. And the black color helps too (yes that's true!).
Re: Led Lensers - Picture of M14 driver
not getting hot is an excellent sign that there is a poor thermal path between the emitter and exterior.
not getting hot is an excellent sign that there is a poor thermal path between the emitter and exterior.
Locoboy5150
Flashlight Enthusiast
- Joined
- Nov 3, 2009
- Messages
- 1,102
Thanks for posting the images McAllan. It is nice to see LED Lenser including regulation in their new lights. I hope that they do the same with all their older models, starting with the X21, the one that really needs it.
Speaking of batteries, does LED Lenser still only recommend the use of alkaline cells exclusively as in the past or has that changed with the new M14?
Speaking of batteries, does LED Lenser still only recommend the use of alkaline cells exclusively as in the past or has that changed with the new M14?
McAllan
Enlightened
Re: Led Lensers - Picture of M14 driver
Lets say the LED get full 1 A at 3.7 v. Yes it might be a little different with PWM and everything.
But to take that number that's 3.7 w of power that needs to be dissipated. Some of it goes as light and some as heat.
Even if we count 3 w is going to heat (we hope not 😉 and I believe it's less by a good margin) then the light still has a very large body. It's _not_ like you small 1 cell light with limited surface - yes they get hot.
So please look at realities. If you've ever made som electronics yourself like small kits and so on you'll soon realize that such a large area for 3 w will mean very limited temperature rise.
Then another thing. No matter what if the LED delivers X joule as heat then X joules needs to be dissipated. 30 min is plenty of time for the heat to stabilize (rate of dissipation from LED = rate of dissipation from light body). If there was no heat path from the LED to the body then it'll be so hot that you could easily melt aluminum which clearly isn't the case.
So please get your basic physics in place and look at realities.
EDIT:
Btw. I didn't say it didn't get hot. Just that temperature rise wasn't a problem.
EDIT again:
Take a look at this CPF post showing the heat path of a P7. I believe it's more or less the same in M14. Might take a look one day.
None the less you can always argue more is better but it's quite sufficient for 3 w keeping the LED temperature down.
Lets say the LED get full 1 A at 3.7 v. Yes it might be a little different with PWM and everything.
But to take that number that's 3.7 w of power that needs to be dissipated. Some of it goes as light and some as heat.
Even if we count 3 w is going to heat (we hope not 😉 and I believe it's less by a good margin) then the light still has a very large body. It's _not_ like you small 1 cell light with limited surface - yes they get hot.
So please look at realities. If you've ever made som electronics yourself like small kits and so on you'll soon realize that such a large area for 3 w will mean very limited temperature rise.
Then another thing. No matter what if the LED delivers X joule as heat then X joules needs to be dissipated. 30 min is plenty of time for the heat to stabilize (rate of dissipation from LED = rate of dissipation from light body). If there was no heat path from the LED to the body then it'll be so hot that you could easily melt aluminum which clearly isn't the case.
So please get your basic physics in place and look at realities.
EDIT:
Btw. I didn't say it didn't get hot. Just that temperature rise wasn't a problem.
EDIT again:
Take a look at this CPF post showing the heat path of a P7. I believe it's more or less the same in M14. Might take a look one day.
None the less you can always argue more is better but it's quite sufficient for 3 w keeping the LED temperature down.
Last edited:
McAllan
Enlightened
Well. I don't think they'll upgrade their older models. But we can hope they'll come out with an MX21 😉
That ought to be a DIY project. Don't know if there's room in the head for a whole lot of AMC7135 - 2 or 3 pr. LED according to taste. Load it with 4 NiMH and it'll shine
Don't know if they still say exclusively alkaline. As said earlier there's no manual with the UK packaging(!) 🙄
But wouldn't surprise me. But I really don't see a problem. 4 NiMH is as said 4.8 v which is the voltage of 4 alkalines after some use. My only suspect is that lithiums may have too high voltage and so cause more heat in the driver. I believe the new NiZn batteries are a no go though as they're even a little higher (to my memory don't count me on it).
McAllan
Enlightened
Re: Led Lensers - Picture of M14 driver
It's no worse than all those tiny waffers. And still it does not change a thing.
Look at this post for a P7. It's about 1 cm or less. Absolute no problem to dissipate 3 w sufficiently. PERIOD
Of course there'll be a little more thermic resistance compared if it was flat against the larger area but that should not translate to any increase in temperature which should be alarming by any means.
Fair enough if you don't like the light. But please either just say that or come with some real critics instead of trolling.
It's no worse than all those tiny waffers. And still it does not change a thing.
Look at this post for a P7. It's about 1 cm or less. Absolute no problem to dissipate 3 w sufficiently. PERIOD
Of course there'll be a little more thermic resistance compared if it was flat against the larger area but that should not translate to any increase in temperature which should be alarming by any means.
Fair enough if you don't like the light. But please either just say that or come with some real critics instead of trolling.
Re: Led Lensers - Picture of M14 driver
the heat flux of their pedestal design is approximately 50% worse than a conventional heatsink design. alternatively, a conventional design is 100% more effective.
how about objective observations instead of blind fanboyism?
the heat flux of their pedestal design is approximately 50% worse than a conventional heatsink design. alternatively, a conventional design is 100% more effective.
McAllan
Enlightened
Re: Led Lensers - Picture of M14 driver
I could say the opposite about you.
It's still quite sufficient for 3 w so what's your problem? You don't need a 0.001 C/W heat sink for a 3 w LED.
Unbelievable :shakehead
I could say the opposite about you.
It's still quite sufficient for 3 w so what's your problem? You don't need a 0.001 C/W heat sink for a 3 w LED.
Unbelievable :shakehead
McAllan
Enlightened
Re: Led Lensers - Picture of M14 driver
And you did measure it? No of course you haven't :thumbsdow
I did a test. Ran it for 15 minutes which should be enough to reach it's max temperature for a given body temperature. Not holding it and room temperature is here 25 C.
OK, ran it for 15 minutes and while on unscrewed the head. Turned it off and as quickly as possible I pointed my Fluke 561 IR thermometer direct at the LED and it read 40 °C (104 °F). By no means objective in any way. And even less Quarks or whatever you like - even holding it in your hand.
And yes - it has same temperature above as under - in fact if there's a difference it should be hotter above as that side is away from heat sink.
So come again
And you did measure it? No of course you haven't :thumbsdow
I did a test. Ran it for 15 minutes which should be enough to reach it's max temperature for a given body temperature. Not holding it and room temperature is here 25 C.
OK, ran it for 15 minutes and while on unscrewed the head. Turned it off and as quickly as possible I pointed my Fluke 561 IR thermometer direct at the LED and it read 40 °C (104 °F). By no means objective in any way. And even less Quarks or whatever you like - even holding it in your hand.
And yes - it has same temperature above as under - in fact if there's a difference it should be hotter above as that side is away from heat sink.
So come again
McAllan
Enlightened
And especially for you, Ragiska.
It probably should be bended in neon that the reason to turn off the LED and then do the reading if because the extremely bright light will give false readings. And from off to measuring wasn't more than 1/4 of a second - not long enough for the surface to cool anything significantly.
It probably should be bended in neon that the reason to turn off the LED and then do the reading if because the extremely bright light will give false readings. And from off to measuring wasn't more than 1/4 of a second - not long enough for the surface to cool anything significantly.
