Here's an LED indicator which was made at home out of a Silicon Carbide (SiC) crystal. The concept is simple, but a bit of trial and error goes into getting that tiny amber spot to light up. The guesswork comes in finding the right piece of crystal. First [KOS] broke it into tiny pieces, then he started poking the chunks with electrified probes to see if he could get some light out of them. … [Read more...]