Or to operate, logic gates in minecraft are a way of using redstone circuits in a manner that a certain combination of inputs, mastering the fundamental building blocks for creating in-game machines. Description from bootstrapstyler.com. I searched for this on bing.com/images
How to make a simple automatic Minecraft cobblestone generator!
this is a simple way to make a cobble stone generator become automatic if you havent seen my instructable on how to make a Cobble stone generator you read have to read it first. this also shows you how to make a repeating redstone circuit.