Minecraft wiki entry for Quasi-connectivity, associated text: Adds 2 ticks delay to signal rising edge (1 tick for piston extension, 1 tick for comparator) and 1 tick delay to signal falling edge, takes up only one space above piston. The difference in rising and falling edge delay shortens pulses by 1 tick. If the piston moving the cauldron gets a pulse shorter than 1.5 ticks, it drops the cauldron in the extended position, turning on the output until the next time the input turns on and off again. A composter can be used for the same purpose.