I have moved this topic from "USB" to "Introductions and general chat" as it it not really about any PIC subject at all. LED, this really is a pointless question. You don't mention what this "protective realy" is meant to do exactly, or why you would think a PIC would be an essential part of it.
Latest test project, an LED matrix display made from one reel of addressable LEDs. here
Go to college and study electrical engineering. Sorry, this forum is to help with programming and designing around PIC devices, we're not here to teach you about basic electronics.
Latest test project, an LED matrix display made from one reel of addressable LEDs. here