LED Burn out Limit???

[chuckfalcon]

Hi everyone.  I am working on a new build and I was wondering if anyone knew how far you can push an LED before it burns out.

Here is the kind I am using: http://smallbear-electronics.mybigcommerce.com/led-8mm-high-brightness-clear-colors/

Currently, I am running a 9V battery, 390ohm resistor, white LED.  Its pretty bright, but I maybe would like to go brighter.  Does anyone know how far it can go?

[bloxstompboxes]

That is a pretty small CLR already. I doubt that going any smaller will allow the LED to get any noticebly brighter. I suspect that if not already, any smaller resistance value will either shorten the life of the LED or cause it to burn out immediately.

[Keppy]

If you go much smaller, then you'll risk burning out your 1/4W resistor.

P=V^2/R
=~9v*9v/390R
=~.2W.

The current power disippation in the resistor is actually a little less than that because some of the voltage drop is in the diode rather than the resistor, but you're still just about of headroom to make any noticeable difference.

[Groovenut]

Most LEDs have a max I_f of 20mA - 30mA

Small Bear doesn't list the spec sheet unfortunately so you'll have to err on the side of caution here

If your white LED has a voltage drop of say 3.6V then

9V-3.6V=5.4V

5.4 / 20mA = 270 Ohms @ 108mW

On the off chance that the max spec is 30mA the numbers extend to 180 Ohms @ 162mW

If you are using an 1/8th watt resistor, you're pushing the limits of the resistor

[GibsonGM]

A better way may be to get some "super bright white" LEDs on fleabay, or see if Aron or Smallbear have them. I've gotten some that were so bright, they'd blind you with anything less than a 10k!!  You will WANT to dim them.   

So, looks like the lumens you want probably can't be had from the LEDs you have...

[electrosonic]

I would go the other way and use the largest resistor your can. More current means more chance of popping and super bright LEDs make it incredibly hard to read the labelling on a pedal on a dark stage.

Andrew.

[chuckfalcon]

Hey everyone thank you so much for your help.  The reason why I want them so bright is because I am wanting them to shine through something.  I am going to be using several LED's and have them all come on at once.

[Jdansti]

Here ya' go. Just watch out for heat and current draw.

https://www.superbrightleds.com/moreinfo/high-powered/vollong-3w-white-high-power-leds/896/

[GibsonGM]

I would go the other way and use the largest resistor your can. More current means more chance of popping and super bright LEDs make it incredibly hard to read the labelling on a pedal on a dark stage.

Andrew.

Except...nothing sucks worse than clicking on something that HAS to be on, looking down at another pedal to see where it is/how it's set, while you're playing, and you're blinded by a super-white for the entire evening, LOL!   This happens more if the tip of the LED is 'proud' of the enclosure...just something to watch out for, look at in a dark room before you call it done...I blinded 1/2 my band like this one time!   
Testing is good....for shining thru, yeah, you probably want very bright!