Does anyone know where I could find some LED's that slowly fade from blue to green.

I've looked everywhere and the best i can find is some that flash blue and green (ebay) 
http://www.ebay.com/itm/5pcs-5mm-Blue-Green-Flash-Flashing-Water-Clear-LED-BG5-/130764714328?pt=AU_B_I_Electrical_Test_Equipment&hash=item1e722f3158

It's close, but it has a bout a 1 sec switch time, and it's flash not fade.
I'm looking for more along the lines of 2.5 sec, 3 sec+
(hopefully for a reasonable price)

It's super easy to find the RBG faders, but not ones without all the colors. I want to avoid the 3 pin led's though, I don't feel like making things more complex then they have to be.

Thanks for your time, I appreciate it :)

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iceng4 years ago
You can use a Blue LED, a Green LED and a 555 IC to fade blue to green in your preferred timing.

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Presentteck (author)  iceng4 years ago
Can you set that to any time you like? (within reason of course)
Also, how well does that fade, or is it more of an alternating blink?

I assume I could probably substitute the 2 led's for a 3 pin bicolor?
  • Yes anytime you like ( may need two 555 ICs for some )
  • Fades very well
  • Also brightens smoothly
  • NO Blinking
  • Yes, two LEDs was my suggestion :-)
Presentteck (author)  iceng4 years ago
Thank you :)
Do you have a suggestion to a circuit?
I've seen a few floating around all a bit different, and I know that simplest isn't always best.
Visit this page for a 555 driven PWM single LED explanation.

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Dual-led-ramping-circuit.jpg
Unfortunately there are no LEDs that have that kind of fading built in. Best you can do is use an RGB LED with micro controller to fade between the colors you want.
Presentteck (author)  mpilchfamily4 years ago
Really? So you're saying that they can have an RGB LED with 2 pins fade through all the colors it wants, but not a 2 color one?
(like this one: http://youtu.be/jBhR3cS1jrk)
They do this with a tiny controller in the led.

That's kinda hard for me to believe.
Yes there are RGB LEDs with built in controllers that will fade through the color spectrum. But finding a 2 color 2 lead LED with build in fade controller may not be possible. It's not that it can't be done, there just isn't a reason for a manufacture to make a 2 color fader.

Your best option is to make it yourself. Either using a 3 lead 2 color LED with a separate controller or using a 4 lead RGB with controller. Then you can set whatever fade speed and delays you want.
Presentteck (author)  mpilchfamily4 years ago
Ok, thanks