Things You'll Need
Instructions
Place two redstone repeaters side by side on two adjacent blocks but facing opposite directions. For example, if you place the first redstone repeater facing north, turn around 180 degrees and place the second redstone repeater facing south, either on the right or on the left of the first one.
Place four redstone dust, connecting the two repeaters in a closed loop.
Place a redstone torch next to the redstone dust to activate the circuit and then remove it. The circuit is now permanently active.