User:MentalMouse42/Sandbox/Misc Diagrams 1

Tiny Charcoal Generator
Source]

It's supposed to feed its product back into the furnace to fuel itself. However, it was an April 1 (2013) posting, so it warrants testing. At first test: Looks like it will not accumulate any charcoal in the chest until both the furnace and the hopper feeding it fuel (level 2) are full. The hopper can be "stuffed" with four non-fuel items in its last four slots, as long as you leave the first slot open for fuel. Then the chest will start getting charcoal after two stacks of charcoal are produced, which will require 2-$1/4$ stacks of wood.

If more than 5-6 stacks of wood are available, another chest can be placed atop the upper hopper.

As usual, using a hopper to take product from a furnace forfeits any experience from the smelting.

cobblestone generator
Cobblestone generator, small pillar Forward repeater must be at least 2, top slab OK for plunger. 1 Extra redstone behind piston lets you put a reset button on the block above the piston.

The second repeater must be set to at least delay 2, or the piston will drop its switch block (the glass). If this happens, the generator can be restarted with the button. If the generator fills its pillar, it will stop until the newest cobblestone is cleared. Besides mining it directly, this can be done by mining any block(s) in the pillar and pressing the button. The pale stone brick indicates some optional blocks.
 * The water and lava can be covered with slabs, especially once cobblestone forms.
 * The redstone dust directly behind the piston isn't actually needed for the normal cycle, but it is needed for the button.