Request for Quickbeam & TheLEDMuseum The Reviewers

[ViReN]

Hello Quickbeam & TheLEDMuseum & Others who Review, Comment, Maintain sites And ofcourse play around with Different types of Flashlights doing various techineques /ubbthreads/images/graemlins/smile.gif

Here is some background first...

I am hooked to your sites, read each and every review that you have done. Appriciate the great deal of the work that has been involved in doing so. I am a newbie, have innovative ideas and crazy but meaningful thoughts, dont have proper equipment (such as lux measuring etc etc) do implement them.

Here is what i want to request to you guys ...
The experiment is very very simple.

1) Take a 5 MM White LED, use proper drive and measure the intencity etc.....keep a note of things

2) take a small flat mirrored surface (2cm * 2cm size) (should be flat (no curved surfaces .... like reflectors)) drill .8 or .9 mm holes at 2.54 mm distance, let the LED pass through it so that base of LED stands touching to the flat surface. Now using same drive current & voltage, measure the intencity etc ... and compare these readings to the previous readings.

I wanted to do this, and i did it, I did it because, i noticed that there is quite some light that is thrown backwards throu the bare LED (apart from the light that is thrown sideways).... you can check it by looking back almost 180 deg to the beam ... i think, it reflects back because of a collimating effect ... the front dome of led acts as an total internal reflector for the LED (similar to the acrilic collimating lenses, commonly used with Luxeon LED's) now, if we some how manage to get this backword light to front portion, wont it be nice ? we will get more bright lights. for the same current & voltage parameters /ubbthreads/images/graemlins/smile.gif

When i did this experiment, I was surprised to see that it was atleast 10 - 20 % more brighter ..... atleast to my eyes (connecting 2 LED's in series 1 with flat reflector, another without flat reflector) ... of recently built switching circuit ....

I want you guys to try this even more now, because when i just observed Quickbeam's review of the new Terralux'x "MiniSTAR1 TLE-4 Minimag Upgrade" .... and those 4 LED's were mounted on bare PCB (green colored) .... this must be giveing a Green tint to the light (though it is small & un noticable) .... attaching a flat surface at the bottom or for that matter, making the PCB itself as a flat reflecting surface could definately increase the light output by 10 - 20 %


I would love to listen to your comments and feedback.

Thanks in advance

Thanks & Regards,
ViReN

 

[Lux Luthor]

Re: Request for Quickbeam & TheLEDMuseum The Revie

Viren,

I'm not Craig or Doug, but I look at 5mm's as having the advantage that they're small and simple to hook up. No additional collimators/reflectors required. I don't doubt your results, and thanks for sharing them, but I would think that if you've got the space an LS with a reflector would do a better job of throwing forward the maximum amount of light. Or, if you are trying to simulate the beam profile of, say a 20 degree white 5mm, I've gotten excellent results with a Fraen LP with a diffusing lens added on top. The more diffusion, the more it approaches a 5mm profile, but with a wider hotspot for less niggling up close. In either case, you get a much more efficient setup, and with much better color quality.

There have also been some awfully small lux mods if space is an issue, but I don't have any of them so I shouldn't comment. Just thought I'd point out that that may be another option for you.

 

[The_LED_Museum]

Re: Request for Quickbeam & TheLEDMuseum The Revie

I don't have the necessary equipment (a flat mirrored surface like you describe) to conduct this experiment, sorry about that. /ubbthreads/images/graemlins/frown.gif
Guess this particular test will have to be up to Quickbeam.

 

[ViReN]

Re: Request for Quickbeam & TheLEDMuseum The Revie

Hello Craig,

There is no need of any special reflector.... you can use the foil the shiny foil that is used to pack Potato Waffers ... etc /ubbthreads/images/graemlins/smile.gif (the inner side) it can be pasted to any General Purpose PCB and then led can be collected, the results wont vary much....

-ViReN

 

[The_LED_Museum]

Re: Request for Quickbeam & TheLEDMuseum The Revie

Well, I don't have a piece of PCB, glue, or a bag of Potato Waffers either; so I still don't know what I'd conduct the experiment with. /ubbthreads/images/graemlins/jpshakehead.gif
Let's see what I *do* have... a drill (not sure if I have the right size bit or not for the LED hole), some cardboard, and I have or could buy some household aluminum foil and glue.

Providing power to the LED and metering it for light output would not be a problem. I have at least four power supplies and at least two photometers in working order. So at least I have that part taken care of. /ubbthreads/images/graemlins/smile.gif

 

[greg_in_canada]

Re: Request for Quickbeam & TheLEDMuseum The Revie

Careful with the aluminum foil. You could short out
the LED.

The shiny mylar from potato chip bags is an insulator
I believe.

Greg

 

[Quickbeam]

Re: Request for Quickbeam & TheLEDMuseum The Revie

Here is how I would re-design the experiment:

push the 5mm LED prongs through a black piece of paper that will absorb most of the light going backwards - take a reading with my Lightbox or similar apparatus. Then push the LED through a white piece of paper and place it on the Lightbox and take a reading. Either way, the piece of paper seals the hole in the Lightbox. This may give a decent approximation of the light lost out of the back of the LED.

I'll try to do something like this this weekend.

 

[ViReN]

Re: Request for Quickbeam & TheLEDMuseum The Revie

Here is the thing that i had done....

The alluminium foil is definately conductive .. its ALLUMINIUM /ubbthreads/images/graemlins/wink.gif ... but the plastic film wont be conductive perhaps....

-ViReN

 

[ViReN]

Re: Request for Quickbeam & TheLEDMuseum The Revie

Quickbeam..... Thats a GREAT Idea /ubbthreads/images/graemlins/smile.gif

See... You guys are lot more techie'r than me.... i just had a thought... and you had come up with an excellent idea.. of absorbing the light that LED Emmits... and measuring what is left behind /ubbthreads/images/graemlins/smile.gif great in deed....

If the results come out in favor (like may be 10 - 15 % light is being thrown backwords) ... then... It SURE will be a good idea to put a flat surface behind those LED's for all the mod's etc... to get 'most' out of it....

Thanks once again.... & U guys are great....

ViReN

 

[ViReN]

Re: Request for Quickbeam & TheLEDMuseum The Revie

Any Updates ?

Thanks & Regards,
ViReN