Bi polar LED's

Status
Not open for further replies.
they accually conduct in both directions..
on the inside they are hooked up with the cathode of one connected to the anode of the other and visa/versa on the other side..
So for example when the current flows in one direction the red will be lit, when the current flows in the other direction the green will be lit..
 
some of them are 3 leads... in all cases it is just 2 LED elements in one case. if it's 2 leads, it will be one color in each direction, if its 3 leads, it is two anodes with a common cathode, or vice versa.
 
RGB LEDs are three LEDs in one package, usually (but not always) with a common anode or cathode (you can get them either way, pretty sure). You just need to control the current through each LED (with a current source/sink, or PWM, or whatever) in order to mix the colors the way you want. If you turned them all full-on it would look white (at least at a little distance).

If you just want something to look pretty and interesting, you could use this flasher/fader thing:

https://www.goldmine-elec-products.com/prodinfo.asp?number=G13897&variation=&aitem=5&mitem=5

j.
 
Ryan Harding said:
so how is this possible, what other components do you need for this, to make it 'decide' what colour it will be?
Click to expand...

it all depends on what lead you pull to +5V (via a resistor) or down to ground. All you need is a PI (they can sink 10mA ???)

They are quite handy (well the 2colour ones I think) for indicating what is happening
 
there are a spicifics LEDs that change there colors depends on a current flew threw them. As the current is higher the materal they are built from getting worm and emitting other color.

as you can see(if you will play with this LED) the color go from green (the cold one) to red(the hot one).

is it answer enoght for you?

p.s. sorry for my mistakes.
 
there are a spicifics LEDs that change there colors depends on a current flew threw them. As the current is higher the materal they are built from getting worm and emitting other color.
Click to expand...

I've never seen such a thing. I've seen red LEDs that when you get them real warm they look kind of orange and green ones that when they get really warm look yellow, but that doesn't last long, because then they turn black.

j.
 
| Think of it like this with the 2 diodes back to
| back. when one polarity is give a single side
|'''''''''''''''''''| will conduct then if the polarity is reversed the
| | other side will conduct
.... .....
\/ /\
''''' '''''
| |
|...............|
|
|
 
well my text pic got messed up when it transfered to the forum but u should get the idea. and remember colors and conductive paths are determined on how you dope the materials
 

That means you are running too much current through them.
 
Status
Not open for further replies.

Similar threads

B
  • Question
Nonpolar, bipolar, polar capacitors
Replies
12
Views
2K
Tony Stewart
B
  • Question
Led's
Replies
11
Views
1K
For The Popcorn
F
Q
About LED's power ratings
Replies
14
Views
2K
danadak
A
  • Question
AC Adapter Polarity 230816
Replies
2
Views
826
AllenPitts
A
C
  • Question
Microcontrollable adjustable and switchable constant current source for driving LED's
2
Replies
25
Views
4K
Les Jones
L
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…