Thursday, July 27, 2006
Pink is the new LED
My first order of parts for the MIDI keytar arrived today: A bunch of LEDs. Of course an electrified guitar has to light up like a fairground, so I’ll have 33 LEDs in total on the guitar.
As the standard red, yellow/amber and green LEDs have been around for over 30 years now and their look is somewhat dated, I ordered pink, blue, cyan and purple LEDs. Hey, I’m hacking a cheap plastic toy, so I’ll just have to do this the cheesy way all along.
The LEDs came from Europkauf, the only seller I found to have 3mm pink LEDs stocked, even though at a premium price, compared to standard LEDs. Something I just found out (and probably should have checked before ordering) is the way that pink LEDs work: They are blue LEDs containing an additional red phosphoric layer that emits red light as soon as the LED is powered. The guy from LED museum has found out that this phosphor layer can be either organic or inorganic. Pink LEDs with organic layers stop emitting their red light after only some hours of operation and turn into substandard blue LEDs.
So I hope that my LEDs are of the inorganic type. I have hooked up one pink LED to my lab power supply and will have it running until tomorrow and then compare it to one of the unused LEDs.
Keytar Project:
Part 1: Building a MIDI keytar
Part 3: Midibox inside
How did the pink LEDs fair over time? I’ve just had one fade to white after a few hours of use.
My test showed no color change after 24 hours of continuous use, maybe that means that they will remain pink.
I have not yet finished the keytar, so the LEDs have not been lit for a longer time since.