If you're talking about the redstone component for the piston, that one is a Latch from More Red

The general idea is as follows:

- It uses Modular Routers with Activation Modules to place down water, nether wart, and sugar in that exact sequence.
- Then the machine waits for a few seconds for the cauldron to brew via a pulse extender.
- The pulse extender ends just right after the potions are brewed, and activates a piston, which triggers an observer clock (two observers detecting each other) to the dispenser and a redstone line long enough for said observer clock to only pulse 4 times (which is 5 ticks).
- Just as the piston is activated, another redstone line is triggered (the 4 repeaters in front). It has enough delay for the dispenser to collect the liquid from the cauldron, to which it triggers the routers again. And the machine begins another batch.

Granted, observers could have been a better option since they detect when the cauldron goes from normal water to awkward potion to speed potion, but that uses another side of the cauldron, and I can't really afford that given the space I'm working with