What's the smallest white LED with the lowest power requirement?

[**DONOTDELETE**]

What\'s the smallest white LED with the lowest power requirement?

Hi,

I'm new here and to LEDs, but I am very interested in them.

I'd like to make a very small flashlight (the size of a six sided game die) using a very small white LED that requires very little power.

I'm looking for a while LED that can operate on 1.0 microwatts/cm2 or a voltage of 5V/cm2.

Does anyone here know of any LEDs that match what I'm looking for?

I don't have very much knowledge in electricity so I'm sorta reaching in the dark (pun intended

Thanks

 

[Charles Bradshaw]

Re: What\'s the smallest white LED with the lowest power requirement?

White LEDs come in 3 and 5 MM sizes. not sure if anything exists for what you want (hopefully somebody knows the answer).

There are many LED flashlights on the market already. The smallest tubular style that I know of is the ARC AAA (look in the Arc Flashlight section). It uses a single AAA.

 

[INRETECH]

Re: What\'s the smallest white LED with the lowest power requirement?

The T1 (3mm) LED is quite small, and is available from several companies - I suggest HP (Agilent), KingBright, NiChia and others

If you are looking for something smaller than 3mm diamter, I suggest SMD (Surface Mount Devices) LEDs

Mike
http://www.inretech.com/

 

[aso]

Re: What\'s the smallest white LED with the lowest power requirement?

What about those SMD chip leds used for backlighting lcds?

EDIT: Mike beat me to it

 

[**DONOTDELETE**]

Re: What\'s the smallest white LED with the lowest power requirement?

Can the LEDs you are suggesting sufficiently light one's way in the dark as a flashlight? I'm not expecting a spotlight, just something that you can see 10 feet or so in front of you.

 

[d'mo]

Re: What\'s the smallest white LED with the lowest power requirement?

The smallest white LED light I am aware of is the Tag Light, available at http://www.techass.com/other/taglite/taglite.php

It's about the size of a jelly bean. I'm not sure about the current though....

 

[Jonathan]

Re: What\'s the smallest white LED with the lowest power requirement?

I'm not sure about the ratings that the initial poster gave; 1 microwatt per cm^2 is _very_ low flux, and when you consider that most LED chips are actually on the order of 0.01 cm^2 or less in size, you are talking about _very_ low power levels. V/cm^2 is not a unit that I've ever seen used. Presuming that what was really intended was total power, and the size measurements were intended to describe how much space the device could take up:

1 microwatt is a minuscule amount of power, and transformed into light through an LED will not be very much light. Most white LEDs operate at about 3.6V and 20mA, or about 70 milliwatts, 70,000 times the power level that was suggested. These devices are typically 3 or 5mm in diameter, and about 3-10 mm long. The semiconductor elements themselves are usually much less than 1mm on a side, and the rest is a plastic package that helps to focus the light. If you don't need the light to be focused, but just want something small that glows, then you can get surface mount LEDs that are 1mmx2mm or smaller.

At 1 microwatt, I'd give even odds that you would be able to see the semiconductor element light up in an otherwise dark room, but I don't think that you could actually illuminate anything to see it.

With the standard LEDs, operated at 20mA and 70 mW, you can illuminate things on the other side of a room, if your eyes are dark adjusted. To supply power to these LEDs, you could use a pair of small lithium button cells. This might get you sufficient energy packed into a small enough volume to make your 'gamers die flashlight'.

-Jon

 

[**DONOTDELETE**]

Re: What\'s the smallest white LED with the lowest power requirement?

I've renamed this thread so it fits the question more appropriately.

 

[Charles Bradshaw]

Re: What\'s the smallest white LED with the lowest power requirement?

In answer to the renamed topic, probably the 3MM White Nichia. The standard 5MM White Nichia has nominal voltage of 3.6 Vdc and current draw of 20 Ma, although the forward voltage varies. So does the brightness grade. I am not sure if the 3MM version draws less or not.

Those lights that use a single 1.5 volt cell, normally have some sort of step up circuit and regulation.

By normal standards, 20 Ma is very little power.

The bleeding edge is Luxeon Star LED, but those are way over your power requirement.