I am creating a redstone system that has a dropper facing upwards into a hopper that in turn points back down into the dropper.
My goal is to be able to lock the top hopper by powering it with redstone. But however I seem to go about this, it seems to power the dropper, sometimes only when it receives a redstone update.
The rules of quasi-connectivity are that "anything that can power a redstone component above your dropper can power the dropper itself, even if the redstone component isn't there."
This means that any way of directly powering the hopper will indirectly power the dropper, and there is no way to lock the hopper without powering the dropper.
Is there a way to lock the top hopper without powering the dropper?
Best Answer
It's impossible not to power the dropper, but it's possible not to make it fire. All you need is not to provide a block update, which would make the dropper check for power and activate.
This example setup works - a solid block does not produce updates even when powered, locking a hopper does not produce an update, and a repeater will produce an update 2 blocks ahead, but it updates the hopper, not the dropper.
Of course at this point the dropper is BUD'ed, which means any update, from any source will make it fire. But that's the most you can do in this configuration.