BILLIE: I gotta right to sing the blues, I gotta right to moan inside …
I gotta right to sit and cry, down by the river …
ADABOT: Whoa! What’s that music?
RUBY: That’s just Billie!
ADABOT: Really? - she sounds kind of sad …
GUS: Yeah, don’t go nuts. Billie’s just got the blues again.
ADABOT: Ohhhh …
ADABOT: Hey Billie, Why so blue?
BILLIE: I suppose that’s just the way I am.
ADABOT: So, you’ve always been blue?
GUS: Yeah, well - she’s made with Gallium Nitride.
ADABOT: Gallium what? What are you talking about?
RUBY: Well, Adabot - inside every LED is a small crystal …
ADABOT: Oh, really …
RUBY: When you connect the short leg of an LED to ground, and the longer leg to positive voltage - voila!
GUS: The crystal glows and the LED lights up!
ADABOT: Very cool - so when electricity flows through an LED’s crystal, it creates light! But why are LEDs certain colors in the first place?
RUBY: The type of crystal used in an LED determines that LED’s color.
ADABOT: Oh - interesting!
RUBY: A red LED like me uses a type of crystal made of Gallium Arsenide - that’s two elements, Gallium and Arsenic, mixed together.
GUS: I use an Aluminium Gallium crystal to get so green.
BILLIE: and Indium Gallium Nitride is what makes me so blue.
ADABOT: Oh - so different crystals make different colored light!
ADABOT: But I’ve also seen LEDs that change color? How do they do that?
RUBY: Well, we usually call those color-changing LEDs – RGB LEDs.
BILLIE: Hey - I’ve got an RGB LED here.
RUBY: Oh good - Let’s take a closer look to see how they work …
RUBY: We call them RGB because inside every one of them are three different types of crystals - one that makes red light, one that makes green light, and one that makes blue.
ADABOT: ohh, R - G - B – red, green, blue!
RUBY: Exactly - and by mixing red green and blue - we can make pretty much any color we want!
GUS: like, say - purple …
BILLIE: or orange …
RUBY: Or even white!
ADABOT: Wow - thanks, guys! LEDs make a lot more sense now!
RUBY: You’re very welcome, Adabot. LEDs are in so many electronic devices, screens, billboards, – even light bulbs …
BILLIE: It’s really important to understand how they work!
ADABOT: You know, Billie - you may be blue, but you light up my life.
GUS, RUBY, BILLIE: Awwwwwww …