For an easier usage, NEI and WAILA could be installed, which show the input and output on the Randomizer.
The Randomizer has one input side and three output sides for red alloy cables, redstone, an adjacent circuit, machine, lamp or anything that can be controlled with redstone signals.
If a redstone signal reaches the Randomizer on the input side, then it changes the transmission of redstone signals via the output sides. In this phase the Randomizer transmits redstone pulses via the outputs sides briefly selected.
If the redstone signal on the input side is terminated, then the change of outputs and stands on a randomly selected combination will stop. In this phase the Randomizer transmits a permanent redstone signal via the chosen output sides.
Using the screwdriver from Project Red, the orientation of the gate can be changed freely in all four directions.