LED Question: Any 2.4V Blue/White LEDs?

Devistater

Gawd
Joined
Mar 29, 2001
Messages
651
Got a question from my brother (quoted verbatim):

Do you guys know where I could buy a 2.4V Blue (preferrably) or White LED? I need it to run off of two AAs in an MX700.

I *really* need to add an LED inside at a particular spot as part of a mod, and it would be easy to syphon off power from the AAs since the wires that pipe power to the mouse are bare. The closest Blue LED I found so far was 3V.

I know there are experts/experienced modders here, so help me out here :)

(P.S. Second question: Could someone elaborate on forward/reverse LED voltages? I saw an LED for sale that claimed a forward DC Voltage of 3.3V, a reverse of 5V, and said that it could be used "with a 12V power supply." How does *that* work out? Wouldn't you need to add some resistors to increase the forward or reverse voltage?)
 

Devistater

Gawd
Joined
Mar 29, 2001
Messages
651
SarverSystems said:
Those batteries would last about 2 minutes.
Funny, the LED on my MX700 (cordless with 2 AA bats) seemed to last a lot longer than 2 minutes.
 

SarverSystems

Supreme [H]ardness
Joined
Feb 9, 2002
Messages
7,408
I would highly recommend temporarily mounting that LED before drilling any holes in the mouse.

You'll be amazed at how quickly an LED can drain a battery.
 

designedforhell

Weaksauce
Joined
Sep 7, 2003
Messages
100
LED power consumption rates are low. For example; I have an LED flashlight that runs off three watch batteries. It has been doing so for a very long time. I haven’t added an LED to my wireless mouse because it would just be one more thing eating away at my batteries!

2.4v is a very low forward voltage for blue, white, or green LED’s. Most are going to be 3.1v to 3.8v although you can find red and amber LED’s in that category. I bet you could use a 3.0v LED in the mouse, do you need a 3mm or a 5mm LED?
 

Mohonri

Supreme [H]ardness
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Jul 29, 2005
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5,749
The voltage rating of an LED is determined by its chemistry. The chemistry also dictates the color of the LED. So basically, the voltage of an LED and its color are a package. Having said that, you can typicaly run an LED at much lower current (say, 3V @ 5mA instead of 3V @ 20-30 mA) than what it's rated at, and still get respectable light levels.

LED power consumption rates are low.
QFT. Two 1800mAh AA batteries (in series to get 3V) would theoretically be able to power a 20mA LED for 90 hours. If an LED is draining your batteries, make sure you have a series resistor to limit the current. LEDs have the tendency to draw more current at lower voltages as they heat up, so they can burn themselves out easily if nothing is limiting the current.
 

Devistater

Gawd
Joined
Mar 29, 2001
Messages
651
Some good suggestions and ideas. I'll definately let my brother know he should test it before perm mounting it in the mouse. Also I didn't think about there possibly being voltage sources that were more than just the 1.2x2v=2.4v of the rechargable bats. There's probably some sorta rectifier or similar in there. Because I doubt all the internal electronics run at only 2.4v.

Current limiting resistor is a good idea.

Anyway his question about forward and reverse voltages from specs, would that be like an LED that was "zenier" capable, able to run in both forward and reverse?

Depending on how his paint job turns out with his mx700, I might just go and paint my brand new mx1000 as well.


Edit: Some research by my brother has turned up a few possabilities:
http://www.coolerguys.com/840556011293.html
http://www.hosfelt.com/en-us/dept_214.html
And http://www.mouser.com has one apparently, their web site search is atrocious but calling them works and they found one over the phone.
 
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