Found a 2 x D cell Maglite in the understairs cupboard. Needs, AFAICWO,
a new spring in the base to make it work, and a new switch cover to make
it complete. http://www.brewstersbatteries.co.uk seems like an excellent
source of spares. Got wondering whether to splash out on a shiny new
bulb at the same time, figuring that a Xenon bulb is bound to be very
shiny, and an LED super-shiny. Surprisingly, according to this:
http://www.candlepowerforums.com/vb/...30#post2168830
the Xenon only gives 40.6 lumens over the base Krypton 36.5 lumens.

And other posts on the same torch-obsessive forum indicate that the
LED only does much the same - but with much longer battery life.
Which is not an issue for me.

But what's wierd to me is the non-linear relationship between
voltage and brightness. E.g. for Xenon bulbs:
2 cell - (40.6 lumens @ 3 volts)
3 cell - (82.5 lumens @ 4.5 volts)
4 cell - (124.3 lumens @ 6 volts)
5 cell - (181.0 lumens @ 7.5 volts)
6 cell - (233.5 lumens @ 9 volts)

How's that work then?

On Thu, 6 Dec 2012 23:02:58 +0000 (UTC), "Fevric J. Glandules"
wrote:

Found a 2 x D cell Maglite in the understairs cupboard. Needs, AFAICWO,
a new spring in the base to make it work, and a new switch cover to make
it complete. http://www.brewstersbatteries.co.uk seems like an excellent
source of spares. Got wondering whether to splash out on a shiny new
bulb at the same time, figuring that a Xenon bulb is bound to be very
shiny, and an LED super-shiny. Surprisingly, according to this:
http://www.candlepowerforums.com/vb/...30#post2168830
the Xenon only gives 40.6 lumens over the base Krypton 36.5 lumens.

And other posts on the same torch-obsessive forum indicate that the
LED only does much the same - but with much longer battery life.
Which is not an issue for me.

But what's wierd to me is the non-linear relationship between
voltage and brightness. E.g. for Xenon bulbs:
2 cell - (40.6 lumens @ 3 volts)
3 cell - (82.5 lumens @ 4.5 volts)
4 cell - (124.3 lumens @ 6 volts)
5 cell - (181.0 lumens @ 7.5 volts)
6 cell - (233.5 lumens @ 9 volts)

How's that work then?

Well they draw different currents, apart from the voltage.

--
Frank Erskine

In article ,
Fevric J. Glandules wrote:

But what's wierd to me is the non-linear relationship between
voltage and brightness. E.g. for Xenon bulbs:
2 cell - (40.6 lumens @ 3 volts)
3 cell - (82.5 lumens @ 4.5 volts)
4 cell - (124.3 lumens @ 6 volts)
5 cell - (181.0 lumens @ 7.5 volts)
6 cell - (233.5 lumens @ 9 volts)

How's that work then?

The power is the voltage times the current. If the resistance was
constant, that would give power proportional to the square of voltage.
But the resistance will increase with the filament temperature, and
the relationship between power and brightness is not necessarily
linear either.

-- Richard

On 06/12/2012 23:02, Fevric J. Glandules wrote:
Found a 2 x D cell Maglite in the understairs cupboard. Needs, AFAICWO,
a new spring in the base to make it work, and a new switch cover to make
it complete. http://www.brewstersbatteries.co.uk seems like an excellent
source of spares. Got wondering whether to splash out on a shiny new
bulb at the same time, figuring that a Xenon bulb is bound to be very
shiny, and an LED super-shiny. Surprisingly, according to this:
http://www.candlepowerforums.com/vb/...30#post2168830
the Xenon only gives 40.6 lumens over the base Krypton 36.5 lumens.

And other posts on the same torch-obsessive forum indicate that the
LED only does much the same - but with much longer battery life.
Which is not an issue for me.

Better battery life is one thing, but another advantage of LED is that
it gives better light that the original bulb when the battery is getting
on a bit. I fitted an LED bulb when the light was getting noticeable
dimmer on my 2D Maglite and with the LED it was super bright and months
later it is still the same (albeit with limited use). I get the same
results with my LED bike light so I guess LED bulbs are less sensitive
to changes in voltage than filament bulbs.

Biggles

Biggles wrote:

Better battery life is one thing, but another advantage of LED is that
it gives better light that the original bulb when the battery is getting
on a bit. I fitted an LED bulb when the light was getting noticeable
dimmer on my 2D Maglite and with the LED it was super bright and months
later it is still the same (albeit with limited use). I get the same
results with my LED bike light so I guess LED bulbs are less sensitive
to changes in voltage than filament bulbs.

Saying "LED bulb" would get you laughed at very loudly in some places.

Anyway, forget all of that, I'm saving up for one of these:
http://www.myfenix.co.uk/fenix-pd32-...ion-740-lumens

On 07/12/2012 09:12, Willy Eckerslyke wrote:
Biggles wrote:

Better battery life is one thing, but another advantage of LED is that
it gives better light that the original bulb when the battery is
getting on a bit. I fitted an LED bulb when the light was getting
noticeable dimmer on my 2D Maglite and with the LED it was super
bright and months later it is still the same (albeit with limited
use). I get the same results with my LED bike light so I guess LED
bulbs are less sensitive to changes in voltage than filament bulbs.

Saying "LED bulb" would get you laughed at very loudly in some places.

Anyway, forget all of that, I'm saving up for one of these:
http://www.myfenix.co.uk/fenix-pd32-...ion-740-lumens

And how many £2.99 Lidl specials is that equivalent to?

I guess somewhat fewer than 20. :-)

--
Rod

polygonum wrote:

And how many £2.99 Lidl specials is that equivalent to?

I've been cheated, I'm sure my Lidl special cost £6.99.

BTW, Lumens are not really a satisfactory measurement of flashlight
intensity anyway so unscrupulous manufacturers will always be able to
exaggerate their output.

On 07/12/2012 14:00, Willy Eckerslyke wrote:
polygonum wrote:

And how many £2.99 Lidl specials is that equivalent to?

I've been cheated, I'm sure my Lidl special cost £6.99.

BTW, Lumens are not really a satisfactory measurement of flashlight
intensity anyway so unscrupulous manufacturers will always be able to
exaggerate their output.

Relax! The metal-body ones are more expensive - I was referring to the
plastic ones available in the last few days or so.

--
Rod

On Dec 7, 2:00*pm, Willy Eckerslyke wrote:
polygonum wrote:
And how many 2.99 Lidl specials is that equivalent to?

I've been cheated, I'm sure my Lidl special cost 6.99.

BTW, Lumens are not really a satisfactory measurement of flashlight
intensity anyway so unscrupulous manufacturers will always be able to
exaggerate their output.

Lumens is a measure of the total luminous flux emitted by the LED,
usually taken for the top bin example from the makers data sheet,
which was acheived in sub artic conditions with an LED they have never
manged to make another of....

Candlepower and candela are peak measurements that get higher the more
focussed the beam, they are the light measurement equivalent of Peak
Music Power Output.

Candlepower Forums have quite a lot of useful information buried in
what remains of the archives, just be aware it is now primarily a
marketing tool for its paying advertisers not a neutral place where
honest advice can be sought.

Maglite are of historic interest only now, LED has better efficiency ,
much more robust and useable lifespan, , small incan lamps can have
rated lifes in minutes,

Cheers
Adam

On 07/12/2012 09:12, Willy Eckerslyke wrote:
Biggles wrote:

Better battery life is one thing, but another advantage of LED is that
it gives better light that the original bulb when the battery is
getting on a bit. I fitted an LED bulb when the light was getting
noticeable dimmer on my 2D Maglite and with the LED it was super
bright and months later it is still the same (albeit with limited
use). I get the same results with my LED bike light so I guess LED
bulbs are less sensitive to changes in voltage than filament bulbs.

Saying "LED bulb" would get you laughed at very loudly in some places.

Anyway, forget all of that, I'm saving up for one of these:
http://www.myfenix.co.uk/fenix-pd32-...ion-740-lumens

I'm not sure that 740 lumens for 3 minutes is much use.
I certainly couldn't land a plane that quick.

dennis@home wrote:
On 07/12/2012 09:12, Willy Eckerslyke wrote:

Anyway, forget all of that, I'm saving up for one of these:
http://www.myfenix.co.uk/fenix-pd32-...ion-740-lumens

I'm not sure that 740 lumens for 3 minutes is much use.
I certainly couldn't land a plane that quick.

I bet you could if you really had to!

3 mins is perfect for taking photos by light painting which is what I'd
be using it for. Underground; camera on a tripod; open shutter; wave
the light around; close shutter...
....then 3 hours in Photoshop trying to make it look natural.

In message , Willy Eckerslyke
writes

Anyway, forget all of that, I'm saving up for one of these:
http://www.myfenix.co.uk/fenix-pd32-...ion-740-lumens

It comes to something when even a torch now has an "intuitive user
interface"

--

bof at bof dot me dot uk

Fevric J. Glandules wrote:

And other posts on the same torch-obsessive forum indicate that the
LED only does much the same - but with much longer battery life.

AIUI you don't just fit an LED instead of a bulb. The LED has to have a
controller/driver which will dictate the output. Maglight's own upgrades
are probably pretty conservative but there are ways of turning them into
serious bat-roasters by mixing different LEDs and drivers if you know
what you're doing. One nutter on a mine-exporation forum has built a
caplamp capable of churning out 11,300 lumens:
http://www.cowdery.org.uk/gloworm.php
(And if you think LEDs don't give out any heat, think again.)

On Dec 6, 11:02*pm, "Fevric J. Glandules"
wrote:


But what's wierd to me is the non-linear relationship between
voltage and brightness. *E.g. for Xenon bulbs:
2 cell - (40.6 lumens @ 3 volts)
3 cell - (82.5 lumens @ 4.5 volts)
4 cell - (124.3 lumens @ 6 volts)
5 cell - (181.0 lumens @ 7.5 volts)
6 cell - (233.5 lumens @ 9 volts)

How's that work then?

Different bulbs for the different voltages, not always giving an
optimal pairing.

MBQ

On Thu, 06 Dec 2012 23:02:58 +0000, Fevric J. Glandules wrote:

Found a 2 x D cell Maglite in the understairs cupboard.

I've got a 3-cell LED one and a 2-cell incandescent one. I generally find
the light output from the incandescent one far superior - it doesn't have
that sickly blue cast, and there's a more gradual drop into shadow around
the lit area (the LED one is much harsher, making it harder to scan for
something at a distance in the dark as shadows "leap out at you").

In terms of brightness of the lit area, it's probably about the same
between the two.

The batteries have lasted a couple of years in the incandescent, so
although I'm sure it chews through them far faster than the LED, it's not
at a rate that I'd consider annoying, particularly in light (haha) of the
better quality. Having said that of course the LED one is about five
years old, so perhaps modern ones are better...

The downside to both of them is that there's no attachment point for a
carrying strap or hook (unlike the little AA-cell mag that I have, which
has a hole drilled through a lug cast into the base)

cheers

Jules

In article ,
Jules Richardson wrote:
On Thu, 06 Dec 2012 23:02:58 +0000, Fevric J. Glandules wrote:

Found a 2 x D cell Maglite in the understairs cupboard.

I've got a 3-cell LED one and a 2-cell incandescent one. I generally find
the light output from the incandescent one far superior - it doesn't have
that sickly blue cast, and there's a more gradual drop into shadow around
the lit area (the LED one is much harsher, making it harder to scan for
something at a distance in the dark as shadows "leap out at you").

In terms of brightness of the lit area, it's probably about the same
between the two.

The batteries have lasted a couple of years in the incandescent, so
although I'm sure it chews through them far faster than the LED, it's not
at a rate that I'd consider annoying, particularly in light (haha) of the
better quality. Having said that of course the LED one is about five
years old, so perhaps modern ones are better...

The downside to both of them is that there's no attachment point for a
carrying strap or hook (unlike the little AA-cell mag that I have, which
has a hole drilled through a lug cast into the base)

but you can get belt loops which will hold a 2 or 3 D version.

--
From KT24

Using a RISC OS computer running v5.18

On Thu, 6 Dec 2012 23:02:58 +0000 (UTC), "Fevric J. Glandules"
wrote:

Got wondering whether to splash out on a shiny new
bulb at the same time, figuring that a Xenon bulb is bound to be very
shiny, and an LED super-shiny.

Ahh, chuck it inna drawer and buy a LED thing with a driver. I have a 2 cell
Maglite with a Maglite LED drop-in, and an extra-bright 3 cell with a LED driver
module made and sold by an engineer as a hobby.

The Maglites are great as a club, for driving a nail, for freezing hands off in
cold weather, all accompnied by a doughnut-shaped ring of yellowish light.
Granted, 3 D cells keep on giving light long after a single AA, but...

I have a similar flashlight to this one:
http://dx.com/p/romisen-cree-rc-n3-3...123a-2xaa-9070

(the RC-N2 model, which doesn't turn up, superseded?), and am very happy with
it. Much brighter than a Xenon Maglite, lighter, light stays bright until the
battery is sucked completely empty. Runs on AA and also lithium cells that I got
very cheap as out-of-date stock. The strobe/flashing is annoying; the earliest
ones just had on/off, but my wife got that one and isn't giving it back. The
flashlight come from China via registered mail -- and it takes weeks and weeks
and weeks to arrive...

Thomas Prufer

On Fri, 07 Dec 2012 17:46:14 +0100, Thomas Prufer
wrote:

The Maglites are great as a club, for driving a nail, for freezing hands off in
cold weather, all accompnied by a doughnut-shaped ring of yellowish light.
Granted, 3 D cells keep on giving light long after a single AA, but...

I have a Maglite-alike which has been a really nice torch over the
years, but thanks to its slightly non-Maglite head is a sod to upgrade
with any drop-in module. Looks like it's a simple LED bulb for that.
I agree, the Chinese fresh-sheet designs are much better and I have a
couple of them already, but the old Mag-alike has sentimental value,
as well as its offensive weapon capability.

Fevric J. Glandules set the following eddies spiralling through the
space-time continuum:

Found a 2 x D cell Maglite in the understairs cupboard. Needs, AFAICWO,
a new spring in the base to make it work, and a new switch cover to make
it complete. http://www.brewstersbatteries.co.uk seems like an excellent
source of spares. Got wondering whether to splash out on a shiny new
bulb at the same time, figuring that a Xenon bulb is bound to be very
shiny, and an LED super-shiny. Surprisingly, according to this:

http://www.candlepowerforums.com/vb/...30#post2168830
the Xenon only gives 40.6 lumens over the base Krypton 36.5 lumens.

And other posts on the same torch-obsessive forum indicate that the
LED only does much the same - but with much longer battery life.
Which is not an issue for me.

But what's wierd to me is the non-linear relationship between
voltage and brightness. E.g. for Xenon bulbs:
2 cell - (40.6 lumens @ 3 volts)
3 cell - (82.5 lumens @ 4.5 volts)
4 cell - (124.3 lumens @ 6 volts)
5 cell - (181.0 lumens @ 7.5 volts)
6 cell - (233.5 lumens @ 9 volts)

How's that work then?

As the voltage goes up so does the current. Power (and hence output
brightness) is related to the product of voltage and current. For a linear
device (current directly proportional to voltage) the power would go as the
square of the voltage.

Lights are notoriously non-linear. For a filament bulb, it is found
experimentally that the current is roughly proportional to the square root
of the voltage so the light output would go as voltage to the power 3/2.

I don't know how a xenon bulb would behave but it's certainly not linear.
--
ξ: ) Proud to be curly

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