View Full Version : Do Not Stare at Flashlight with Remaining EYE.

11-01-2009, 07:26 AM
My latest project is a lightweight high power LED flashlight. We both have grown tired of the very bright but very large and heavy 8 BILLION CANDLE POWER flashlight we use to check on the yard at night. This one is just as bright and a lot nicer to hold. Run time should be around half an hour on 4 NiMH AA batteries. It uses 3 Cree Q5 LED 200 lumen modules.



All of the light in this scene is from the flashlight. It is so bright it actually turns the air blue. As far as I can tell there is no smoke in the air and we don't have any other sources of pollution. It must be scattering from the air molecules the same as it does to make the sky blue.


11-01-2009, 07:29 AM
That's not a flashlight - it's a vulcan death-ray! :D

It's fantasic Evan, I see the handle you were machining a week or two back, wondered what it was for.


John Stevenson
11-01-2009, 07:31 AM
Colour me impressed, I'm just waiting to get a few more $$$ into my paypal account and them I'm going to order a few of these.
Skint at the moment as my paypal account only gets topped up when i sell something and I need to get sorted and get a load of crap [ sorry very desirable goods ] on Ebay.


11-01-2009, 09:22 AM
"Set Phasers to stun":D

Nice light,you should go into production,that could easily fetch a good price on the shelves.

11-01-2009, 09:23 AM
It's fantasic Evan, I see the handle you were machining a week or two back, wondered what it was for.

that was the first thing i noticed as well.

i like that, Evan. how does the light compare to something like normal 120V 120 watt spotlights?

andy b.

11-01-2009, 09:36 AM
It's 15 watts of the latest and brightest LEDs on the market. Of course that will change in a few days. These LEDs seem to be about 3 times more efficient than an equivalent quartz halogen lamp per watt of input. That is because virtually all the output is in the visible spectrum. That makes it similar to a 50 watt halogen bulb which is what is used in most of the handheld TRILLION CANDLEPOWER lamps.

There is a problem with selling something like this as a commercial item. The light source is so small that the energy density is far higher than an equivalent incandescent bulb. It really isn't eye safe and could attract a lot of liability.

11-01-2009, 09:48 AM
I've got a 5 watt flashlight that I made the mistake with the other night of trying to find a tick on our WHITE west highland terrier.

Been snow blind ever since.

Evan, that is an amazing device!

But when will you set up an IR perimeter?

11-01-2009, 09:52 AM
Evan could you give us the SKU of that emitter please?

11-01-2009, 09:59 AM
It's SKU 11621 @ $8.69 each.


11-01-2009, 10:08 AM
But when will you set up an IR perimeter?

Not a far fetched idea. It seems that we now have a cougar living on this hill with us since earlier this year when I first spotted it. It has killed an alpaca, a sheep, a goat and robbed a neighbour's squirrel trap as well as hunting the local deer. The deer have adopted the strategy of staying as close to the house as possible much of the time. This flashlight is bright enough to seriously dazzle a predator with (formerly :D ) good night vision. I am considering making one for the smoke pipe.

11-01-2009, 10:16 AM
Thank you. I will order a handful of them tomorrow. If anyone in the UK wants to tag some on my order please let me know via PM.

11-01-2009, 11:10 AM
Take note: I reported this when I first received and tested these modules. They are rated to 18 volts BUT they seem to use a shunt regulator. This means that if you run them at much more than about 6 to 7 volts dc they become very hot. 12 volts is too much to easily heat sink the waste heat. They run best on 4.5 to 6 volts.

11-01-2009, 12:10 PM
Thanks for the info. I plan to run at least two of them on 3.7V mobile phone batteries which are plentiful & cheap.

11-01-2009, 12:18 PM
They will operate acceptably down to about 3.4 volts at reduced brightness. At 3.7 nominal they will produce about 70% brightness judging by the current. That is still plenty bright.

11-01-2009, 01:20 PM
I used these units in goosenecks for machine lights running on my small hybrid solar-windmill 12 volt system.At 10 minutes of use the heat problem seems acceptable but maybe I need to use a resistor for longer use time?

11-01-2009, 01:52 PM
Thank you. I will order a handful of them tomorrow. If anyone in the UK wants to tag some on my order please let me know via PM.

That is a kind offer Peter but not necessary. Shipping is free to UK.

It may be even counter productive as an import over 18.00 is possible to get hit with import duty and handling fee.

11-01-2009, 02:19 PM
You could run them with an external resistor but you will have to experiment to find what value works well. The usual calculations won't help since there is an internal regulator in the module and we don't know what it is like.

Alistair Hosie
11-01-2009, 02:42 PM
Thel ittle pakistani corner shop in Galsgow sells stronger more modern designed ones for 0.99p a dozen.There actually very good.Alistair

11-01-2009, 03:09 PM
Here is why you shouldn't look directly at the emitters when on. It's at least as bright as the sun, probably brighter. They only thing that will save you from a black spot on your retina is that it contains practically zero infrared.


11-01-2009, 03:41 PM
hmmmm. so if i use D-size NiMH batteries and about 6 or 7 of those lights i should be able to blind just about anything that attempts to get near the house. and it would double as one hellacious spotlight. :)

i think the neighbor and i are going to have some fun.

andy b.

11-01-2009, 03:44 PM
Just think what would happen if you made it strobe at around 15 cycles per second. I'll bet you could induce an epileptic seizure in a corpse.

11-01-2009, 05:23 PM
And here's silly me thinking that you could put a lens in front to focus all three to a tiny dot for micro-welding purposes :)

11-01-2009, 05:39 PM
No infrared. Visible spectrum does not deposit heat efficiently.

11-01-2009, 05:52 PM
Evan, you have invented the first self defense flashlight!

Tony Ennis
11-01-2009, 06:04 PM
Evan, master of heat-sinks.

I'll be nagging you soon about LEDs methinks.

John Stevenson
11-01-2009, 06:21 PM
I'd like to see a pic of it outdoors, same area, with the two outside lights angled a bit to one side just out of interest to see what the spread is.


11-01-2009, 06:46 PM
I will try that tonight. If I turn it on it's side I can angle the lights easily.

I was also thinking of making a lenticular diffuser for at least one of the emitters.

John Stevenson
11-01-2009, 06:55 PM
Did you buy any diffusers or lens from D Ex ?

11-01-2009, 06:57 PM
you could always use it instead of an x-ray machine, just shine it through folks an look at the other side.
dont point at any aeroplanes, dont think the FAA would like it!
well made an suitably exotic

11-01-2009, 07:08 PM
No John, I haven't. I'm going downstairs now to cut some from some failed 3D lenticular sheets I made in my 3D monitor experiments.

11-02-2009, 07:14 AM
Here are the pictures John. They were all taken this night in sequence. The top is with all three aimed together, the second is with only a slight spread. The third is with a spread so that the main beams do not overlap and the bottom one is through a lenticular diffuser on all three beams.

Subjectively to my old eyes the appearance of the photos is pretty close to how it looks in person with unadapted vision. It's actually somewhat understated because there was a moon up and I could see slight details in the areas that appear fully dark.


11-02-2009, 09:46 AM
Evan, wow, works as good as it looks too, you come up with more neat things then one man should be allowed to :D

What was the approximate distance in the pics?


11-02-2009, 10:27 AM
It's about 100 feet. The beam is good to maybe 300 feet which better than I can say for my eyes.

11-02-2009, 10:29 AM
Evan: Have you tried using these wired in series.
I'd like to use a 24V power source (only cause I have one) and power
a bunch of these for use to replace my streetlight. (yard light)
I'm thinking, cause, of the internal Regulators, One might want to hog the Voltage over the others in the series.

Also... Do have any Links or have you seen any spectrum specs?
I'm wondering how friendly the spectrum output is to the telescope folks.
A couple of filters I use in Astrophotography are in the near IR.
The fact that they are very directional and not a lot of light is wasted shining upward is a plus too.

Tom M.

11-02-2009, 10:43 AM
I haven't tried them in series and I don't expect it would work.

The spectrum is as per the blue line below. The easy way to run them is from the 5vdc output of a micro atx power supply. It would handle about 20 of them.


11-02-2009, 11:11 AM
You guys need to check out candlepowerforums.com if you're going to get into this stuff.

Paul Alciatore
11-02-2009, 11:29 AM
I haven't tried them in series and I don't expect it would work.


Why do you say that? Offhand, I would think it would work.

11-02-2009, 11:38 AM
Why do you say that? Offhand, I would think it would work.

One possibility is they're using switching regulators so the current through them is not pure DC. If you put three in series then the pulsed current is seen by the other units. It's like having three rotary switches in parallel with different rotation speeds - the chances of them all being on at the same time is less than 100%.

B-passing them with large capacitors can help this but now you're running into space problems.

11-02-2009, 12:52 PM
It depends on the transfer characteristic of the entire module too. They shut down if they become too hot. I just have a feeling that they won't work in series, especially if there is any temperature difference between the modules.

11-03-2009, 10:30 PM
i may have another use for one of these. i have an old tractor with a 6V electrical system. the standard rear utility light is about a 6watt bulb. how would one of these LEDs hold up running off the tractor's somewhat unsteady 6V? heck, i guess i could even make a bracket to use two as headlights.

andy b.

11-03-2009, 10:33 PM
Now that I am finished having children and no effects of being around this light will be passed on to future generations, I believe it would be safe enough to make this atomic flashlight!

Love it.

The Artful Bodger
11-03-2009, 11:29 PM
Hmmmmm.... maybe I could put a couple of these on my 510mm f1:6.8 'Photo Sniper' and get auto focus in the dark at 50 metres!:rolleyes:

Tony Ennis
11-04-2009, 12:17 AM
It is hard to believe we're talking about using two 6v LEDs as headlights.

I need to run some DC in my house.

11-04-2009, 10:01 AM
Well, I did say that it would only be a few days before something better came along.

Here is a new module from Cree that is TWICE as bright. It's still rather expensive at $25.50 but it is rated at 410 lumens instead of 200. :eek:


If you are looking for general LED lighting here is a multiple emitter module that runs on 20 volts and puts out 4000 lumens, about the same as a two tube fluorescent lamp unit. It uses about 2/3 to half the power of a two tube lamp with ballast. Because of the way the light is concentrated it would make an excellent replacement for a 500 watt outdoor floodlight. I think I may order one to try.


11-04-2009, 11:09 AM
Here is one rated for 900 lumens: http://dealextreme.com/details.dx/sku.14413

Still they are a bit bigger and more expensive than the ones you used..

11-04-2009, 11:34 AM
Looks like LED headlights are not too far away. Such an idea was borderline Sci-Fi only 10 years ago.

11-04-2009, 04:53 PM
I ordered some of those 200 lumen ones. A couple are going to be machine lights and a couple to play with.

11-04-2009, 08:22 PM
Looks like LED headlights are not too far away.

Actually, they're here, now.



11-28-2009, 01:06 PM
I ordered some of those 200 lumen ones. A couple are going to be machine lights and a couple to play with.

I just got home from a fortnight working away to find a pack of these waiting for me. Thay are very bright as Evan says, but more exciting than that is that the deep reflector that focuses the light into a narrow beam simply un-screws, and that produces a very wide bright uniform light! I'm just grafing one of the emitters into my 6V 4ah hand-lamp which runs down in a few minutes with it's halogen bulb, then I'm going to make a shallow dish reflector/heatsink to use a Cree emitter as a machine light.

Pics when I get something set up.

11-28-2009, 02:07 PM
Evan...That is a neat design. Is that the lexan pistol grip you posted in a previous thread? Looks good and does a good job. Keep up the good work.

11-28-2009, 02:11 PM
Evan, you have invented the first self defense flashlight!

Nope, not even close to being the first. But Even has designed and built a VERY nice light, highly functional and nice on the eyes. It's a piece of art. Kudos on the execution.