Minecraft wiki entry for Randomizers, associated text: Variations: If the dropper is powered indirectly (for example, by quasiconnecitvity or an adjacent powered block), the hopper won't be deactivated and will immediately push the item back into the dropper. This turns the circuit into a monostable rising edge detector with a 3.5-tick output pulse (still with a random power level of 1 or 3).