LED torches

Tony Cross said:
Further to this I've thought about getting an LED spotlamp type torch but their light output is rated in lumens and that means nothing to me. I did sort of understand candle-power, so what sort of lumens would I need to give the same sort of brightness as a million candle-power and are there any LED spotlight torches that are that bright?
Click to expand...

Most of the torches advertised as a "million candlepower" are incredibly dull.
For the boat where a larger size is not important something with a cree XM-L U2 with around 800 lumens will be much brighter than anything you have seen before.

http://www.flashaholics.co.uk/fenix/fenix-tk41.html
 
Sailing really takes it out of you. At least I'm whacked after just 2 days crewing for a mate.
Meant to reply last night but too whacked.

Cree XM-L U2 950-Lumen

Cree XM-L U3 1100-Lumen

Cree XM-L2 t6 1100LM

I have been tinkering with these great little buggers and can state from my research (that is all I am good at - my website is poor, my comm skills are poor, my sales are nill, my redundancy package is poor......)

And can tell you that the U3 cree uses less Amps than the U2 and the T6 for the same voltage.

So I am converting all my torches to U3 - FANTASTIC brightness and batteries last longer.

If driven properly and heatsunk properly etc it is the dogs dangles.

I buy the LEDs for a tenner and 2 hours later job is done. Can't believe some of the torches with same gubbins cost over £100.

Get a Cree U3, do a bit of soldering and you can have your own SUPER torch for not a lot. AND it will last a long long time. Use decent lens, maybe the one in the torch already and you can at least double the effectiveness of the LED too.
 
gadget user said:
Cree XM-L U2 950-Lumen

Cree XM-L U3 1100-Lumen

Cree XM-L2 t6 1100LM
Click to expand...

I'm really puzzled by all this stuff!

First Cree's data sheet gives lumen output at 700mA (6V version) for the U2 as 300, the U3 as 320 and the T6 as 280, so diffferences seem quite small. These are at 85 deg C BTW.

Second they show that at 2A current - the max they show - the light output is just over 200% of the 700mA output. I can't find any mention of what it does to the life and temperature!

So where do these figures of 1100 and so on come from?

Not saying it's impossible, just that the info seems contradictory, as do many claims on the ebay torches, some evne above 1100.

Incidentally http://www.ebay.co.uk/itm/Cree-XM-L...974?pt=LH_DefaultDomain_0&hash=item337f1b1b3e offers a U3 for £3 rather than £10!
 
The XM-L will take up to 3A.

The specifications for a lot of torches sold are not even remotely truthful, but the better brands quote ANSI out the front lumens.
 
So anyone looking for a serious torch here's something http://www.amazon.co.uk/dp/B00AM55G2U

85w HID "possible to illuminate every inch of a five acre field while standing in one corner with a beam of light as brilliant as daylight"

61Fqzf7eu%2BL.jpg
 
Beware chinese copies!

Not the same animal.

As Noelex says, I run my Cree up to 3Amps and the brilliance is blinding - literally - arc eye - not good for you, but good for illuminating AWAY from you.

Even at 1A proper Cree LEDs are brighter than many people have ever seen an LED before.

If you know what you are doing you can make an AMAZING torch very cheaply and safely and these £100 plus price tags are ridiculous.


Troubadour said:
I'm really puzzled by all this stuff!

First Cree's data sheet gives lumen output at 700mA (6V version) for the U2 as 300, the U3 as 320 and the T6 as 280, so diffferences seem quite small. These are at 85 deg C BTW.

Second they show that at 2A current - the max they show - the light output is just over 200% of the 700mA output. I can't find any mention of what it does to the life and temperature!

So where do these figures of 1100 and so on come from?

Not saying it's impossible, just that the info seems contradictory, as do many claims on the ebay torches, some evne above 1100.

Incidentally http://www.ebay.co.uk/itm/Cree-XM-L...974?pt=LH_DefaultDomain_0&hash=item337f1b1b3e offers a U3 for £3 rather than £10!
Click to expand...
 
gadget user said:
I run my Cree up to 3Amps and the brilliance is blinding - literally - arc eye - not good for you, but good for illuminating AWAY from you.

Even at 1A proper Cree LEDs are brighter than many people have ever seen an LED before.
Click to expand...

OK, so what voltage do you need to drive 3A through it? Does 2 lithiums or 4 alkalines do it?
Pretty hefty current - must be quite a short discharge time on 18650s or Cs or Ds (and short LED life if on for long I imagine).
Of course you don't always want that much light. E.g. my mini Maglite - not LED - is enough to look at the sail telltales at night.
How do you turn down the wick when you want to?
The voltage variation is small isn't it?
 
Troubadour said:
OK, so what voltage do you need to drive 3A through it? Does 2 lithiums or 4 alkalines do it?
Pretty hefty current - must be quite a short discharge time on 18650s or Cs or Ds (and short LED life if on for long I imagine).
Of course you don't always want that much light. E.g. my mini Maglite - not LED - is enough to look at the sail telltales at night.
How do you turn down the wick when you want to?
The voltage variation is small isn't it?
Click to expand...

You can look up the specs but its about 3.4v from memory.
Lithium batteries are ideal for this sort of application.

2x 18650 batteries have enough capacity to drive the led at 3A for about an hour an half. The electronics keep the brightness level constant as the battery voltage drops.
All the good led torches have multiple brightness levels (usually 4 or 5 logrithmic spaced) and will operate continuously for many days on the lowest setting.
 
noelex said:
You can look up the specs but its about 3.4v from memory.
Lithium batteries are ideal for this sort of application.

2x 18650 batteries have enough capacity to drive the led at 3A for about an hour an half. The electronics keep the brightness level constant as the battery voltage drops.
All the good led torches have multiple brightness levels (usually 4 or 5 logrithmic spaced) and will operate continuously for many days on the lowest setting.
Click to expand...

OK, the data sheet I found before talked about 6V and 12V versions and only up to 2A - must have been packaged somehow.
Now found the component data sheet, yes it does show 3A max, voltage from about 2.65V threshold to 3.3V for 3A, 2.9V for 0.8A.
I imagine there are purpose made chips for regulating them? I've seen one on 200mA LED lamps but not for 3A!
 
Troubadour said:
OK, so what voltage do you need to drive 3A through it? Does 2 lithiums or 4 alkalines do it?
Pretty hefty current - must be quite a short discharge time on 18650s or Cs or Ds (and short LED life if on for long I imagine).
Of course you don't always want that much light. E.g. my mini Maglite - not LED - is enough to look at the sail telltales at night.
How do you turn down the wick when you want to?
The voltage variation is small isn't it?
Click to expand...

As Noelex says.

But I recently installed a Cree for a mate and the INITIAL supply voltage was 6 Volts. Meant I had to use a big 10Watt resistor to get down to correct voltage and current. Ran at 2.5 Amps because he said it was too bright otherwise.

Remember, current is the important factor with LEDs once the 3.3 or 3.4 threshold voltage has been achieved.

Extra heat sinks are key to long life.

I am running a Cree U3 in an old torch on 3 AA cells and achieving just under 1 Amp (i'm using a constant current driver) and so far over 24 hours constant illumination. That's not bad. Tesco Ultra power batteries or something. These are real Crees of course, maybe Chinese copies are different / less efficient.

Experimentation has not finished yet.

I'm having fun even if I am not earning anything from it. I really can't believe the price of the torches talked about on here. I wish I could get in on that market. Talk about profit margins. I've converted all my torches for not a lot, got a great light under the stairs to replace the silly glow worm one that was there, the list goes on.

Off sailing later for my mate again. His boat is sprouting LEDs all over the place (my test bed) - got to go and fix the electrical supply to the mobile phone on the boat because it has failed and my remote control project is not working at moment.

Buy some Crees and have a play.
 
Troubadour said:
OK, the data sheet I found before talked about 6V and 12V versions and only up to 2A - must have been packaged somehow.
Now found the component data sheet, yes it does show 3A max, voltage from about 2.65V threshold to 3.3V for 3A, 2.9V for 0.8A.
I imagine there are purpose made chips for regulating them? I've seen one on 200mA LED lamps but not for 3A!
Click to expand...

I am going to send you a pm offering free advice and any product at cost. Some of what I do is experimental and I am hoping to patent it and so forth so I don't want it all out in the public domain yet. But I realize that I am making no money at moment and maybe by doing stuff for free will get the word around that I am an ok guy and start to dribble in an income before I can take off like Dyson - hah! here is to dreaming
 
Troubadour said:
I imagine there are purpose made chips for regulating them? I've seen one on 200mA LED lamps but not for 3A!
Click to expand...
Yes there are loads of commercial pre made drivers available for these LEDs. It is not generally worth making your own.

Here is an old one I had lying in my toolbox from an abandoned project. This one is for 12v input and a variable output from 0.350-1A.
There was not much call for over 1A before the chips like the XM-L were released, but there should be plenty of drivers for higher currents available now.
 
You can buy cheap and throw away.

When my lenser went wrong I phone the coompany for repair and they said they had not been available in UK for more that 2yrs so replaced it FOC.

I have a number of torches Fenik and Lenser are best IMHO but as with all cree technology while brilliant considering power consumption to get a spotlight beam they still have some more development work needed.
 
Some photos

Just took some photos.
The single bright light is a Cree - not even a powerful cree actually, but it does have a focusing lens.
You can see it outshines my car's headlights.
Just a quick comparison, not exactly scientific, but I found a camera and torch in my glove box just now whilst on an errand and thought I'd try a few snaps.
photo 1 is headlights, photo 4 is a single cree torch I made. Photo 2 is headlights and photo 3 is Cree torch on roof and it outshines the headlights as you can see.

Cree rule!
View attachment 35505View attachment 35504View attachment 35503View attachment 35506
 
Look no further than this Chinese secret
http://www.banggood.com/Wholesale-C...terproof-Diving-Flashlight-Torch-p-54536.html
-you will need the batteries and charger but battery lasts forever when charged-great for blinding burglars-the light is so strong and focused.
Its rated as a deep diving torch-triple seals;screw in lense to light and what is unclear on attached link is that if you screw in slowly it strobes.
I imagine to find a UK branded equivalent you would be paying lots of money from a specialist dive shop.
It has a lanyard and velcrose wrist strap and it shows what Chinese manufacturers are capable off.
Worth every penny.
 
You must log in or register to reply here.

Other threads that may be of interest

mogmog2
Maxwell windlass 10 VW looks interesting (to a windlass noob)
2 3
Replies
59
Views
1K
mogmog2
mogmog2
geem
First 6 months with no gas onboard
2 3
Replies
41
Views
1K
Baggywrinkle
Baggywrinkle

Share this page

Top