Yet another LED issue.

[isunktheship]

I read through some LED threads, and I think I may have run into a problem that they have as well...

I wanted to change red and green lights on my sound controller to blue and white.

I matched up the right size, and ordered them. I figured that an LED was an LED, but I was wrong. I later read that blue and white LED's usually require 4v :(m versus the 1.3-2.0. Now I have 7 superbright blue and 7 superbright white LEDs.

EDIT: I tested it with a 9v battery, and they work... 3 work at once. I'll try 4 later, unless the number doesn't matter.


I have to test the LED's as well, so I'm going to find a battery somewhere... I don't have any 9v batteries, so I'm going to try to find a AA.

[xmastree]

So, what's the problem? Did you try one?

LED's don't require a voltage, they require a current. When passing that current they will have a certain voltage across them.

Usually, to get the correct current, they are run from a higher voltage (5V for example) and a resistor is placed in series with them to control the current.

You may find that the blue LEDs work ok in the sound controller. What is a sound controller anyway?

[Nagoshi]

probably an external sound controller like there are in X-Fi and Audigy cards.

[isunktheship]

It's the little black box here:
http://www.logitech.com/index.cfm/products/details/US/EN,CRID=2177,CONTENTID=9586

Uhh... and this pic is linked from google.
http://www.tomshardware.fr/images/av/20031203/Logitech_z5300_1.jpg

[xmastree]

How many LEDs are in that controller? I would suggest just try one and see what happens. The worst case, it won't light. You won't cause any damage (unless your soldering skills aren't up to the task...).
If it works, try more, if it doesn't, put the original one back.

[isunktheship]

There are 7 greens and 6 reds. I need to get a solder sucker, or whatever they are called, to make it nice and clean.

[DevilTeck]

So, what's the problem? Did you try one?

LED's don't require a voltage, they require a current. When passing that current they will have a certain voltage across them.

Usually, to get the correct current, they are run from a higher voltage (5V for example) and a resistor is placed in series with them to control the current.

You may find that the blue LEDs work ok in the sound controller. What is a sound controller anyway?

sorry to say xmastree LED's do require a certain voltage to forward bias. they are the same as a diode but require more voltage to forward bias, regular LED's require 1.4 to 1.7 where as super bright's ussually require 2 all the way up to 4.5 volts. what you can do is try and find a data sheet on the LED's in question and it will tell you the min voltage to forward bias and the max current rating. Now the current rating matter because if the current in the circuit is to much then you have to use a resistor to limit this current to about 20% less that max(typical to allow for current surges in the system).

[Spawn-Inc]

this isn't really an issue as i have built it with success. i built a nintendo wii wireless sensor bar. it has 28 infrared LED's, 2 sets of 14. each set runs off a AAA battery in parallel. it gives me maybe 10 or 15 feet more than the stock sensor bar provides which is about 15. after that the hand/mouse starts jumping around. here are some pictures of it. it wasn't fun working with infrared LED's as you have to use a camera to tell if there working or not.

http://inlinethumb48.webshots.com/111/2083743470100511463S600x600Q85.jpg

http://inlinethumb06.webshots.com/1669/2347372160100511463S600x600Q85.jpg

http://inlinethumb49.webshots.com/496/2336385590100511463S600x600Q85.jpg

thats wood glue holding them in place.
http://inlinethumb47.webshots.com/1198/2787146390100511463S600x600Q85.jpg

i still need to add a switch so i can turn it off and on easier.

[Drum Thumper]

this isn't really an issue as i have built it with success. i built a nintendo wii wireless sensor bar. it has 28 infrared LED's, 2 sets of 14. each set runs off a AAA battery in parallel. it gives me maybe 10 or 15 feet more than the stock sensor bar provides which is about 15. after that the hand/mouse starts jumping around. here are some pictures of it. it wasn't fun working with infrared LED's as you have to use a camera to tell if there working or not.

http://inlinethumb48.webshots.com/111/2083743470100511463S600x600Q85.jpg

http://inlinethumb06.webshots.com/1669/2347372160100511463S600x600Q85.jpg

http://inlinethumb49.webshots.com/496/2336385590100511463S600x600Q85.jpg

thats wood glue holding them in place.
http://inlinethumb47.webshots.com/1198/2787146390100511463S600x600Q85.jpg

i still need to add a switch so i can turn it off and on easier.

Japan has NOTHING on the rest of the world! Just look at the insanity that we modders pull off EVERY DAY!

+rep for that man. That's hella pimp.:up: :D

[Spawn-Inc]

and hey if you don't know how to wire up a bunch of LED's then just get 2 candles. but make sure the flame is open and not covered by anything.

[xmastree]

sorry to say xmastree LED's do require a certain voltage to forward bias. they are the same as a diode but require more voltage to forward bias, regular LED's require 1.4 to 1.7 where as super brights usually require 2 all the way up to 4.5 volts.What I mean to say is that, if an LED requires 1.4V, then simply rigging up a 1.4V supply isn't the right way to power it. You need to aim for a particular current, bearing in mind that it will drop 1.4V.

[Spawn-Inc]

What I mean to say is that, if an LED requires 1.4V, then simply rigging up a 1.4V supply isn't the right way to power it. You need to aim for a particular current, bearing in mind that it will drop 1.4V.

if you look at my sensor bar i have no resistors just 14 infrared LED's in parallel hooked up to a AAA battery. so my question is what is bad about not aiming for a particular current? will the battery or LED's not last as long.

[xmastree]

What's bad about that layout, despite the fact that it works, is that you can't guarantee that all the LEDs are getting the same current. Slight tolerances in manufacturing might make some brighter than others. For IR, this is less of an issue as you can't see them.
No resistor, but you're relying on the internal resistance of the battery to limit the current. If you put too much current through them, you will eventually damage them, and drain the battery faster. Although they're pretty tough, so in most cases you'll get away with it just fine.

[FireFoxConn]

What your trying to do depends all on if the circut is in series or in parallel.
Also if the original LED supply voltage is around 3v you obviously can't use a blue or white LED which uses 4.5v-6v. I would be careful playing with this because if the diode burns out it can fry something on the board...