Maglite

[Fevric J. Glandules]

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.

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: 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?

[Frank Erskine]

Well they draw different currents, apart from the voltage.

[Richard Tobin]

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

[Biggles]

the Xenon only gives 40.6 lumens over the base Krypton 36.5 lumens.

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

[Willy Eckerslyke]

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:

[Willy Eckerslyke]

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:

if you think LEDs don't give out any heat, think again.)

[polygonum]

I guess somewhat fewer than 20. :-)

[bof]

In message , Willy Eckerslyke writes

interface"

[Man at B&Q]

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

MBQ

[dennis]

I certainly couldn't land a plane that quick.

[Willy Eckerslyke]

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.

[Willy Eckerslyke]

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.

[polygonum]

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

[Adam Aglionby]

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

[Willy Eckerslyke]

That's what I said innit. Sort of...

The mine exploration forums can be useful too, though results are generally flashlight envy and an arms race to out-dazzle and out-spend everyone else.

[Chris J Dixon]

Something similar to both has appeared in the local Poundland from time to time.

Chris

[Jules Richardson]

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

[Andy Burns]

Mag Instrument seem to have realised this, and now produce truncheons with LEDs as well as those with incandescent lamps.

[Steve Terry]

Poundlands 9 LED headband torch produces an amazing amount of light for the money, and conveniently runs on 3 x AA cells

BTW poundland are currently offering 20 JCB carbon zinc cells (10 x AA, 10 x AAA), and IKEA 10 x AA lithium also for £1

Steve Terry

[docholliday93]

On Friday, December 7, 2012 2:54:24 PM UTC, Willy Eckerslyke wrote: =20

the one referenced in this thread reminds me that twenty years ago a numbe= r of people in my lab were squeezing a 10W tungsten halogen bulb and a suit= able number of Nicads into the torches which were made to use the flat 4.5V= batteries - very impressive for short term use but liable to melt if you d= idn't switch off soon enough...