I was wondering if anyone knew of a proper way to get a pressure plate to trigger a series of pistons instantly, but have their deactivation delayed by about a variable number of seconds.
I've tried this with a NAND gate and simply adding repeaters but this actually causes the door to open and close rapidly 2-6 times depending on how many repeaters you place.
Any help is appreciated.
Best Answer
A simple pulse lengthener will work here.
It works like this:
The first block gets powered from the pressure plate (or you can power it in some other way), the redstone line immediately takes power from there, so all the pistons go up instantly. After some time the repeater draws power from the block and powers the next block, and so on...
When you step off the pressure plate, the first block no longer powers the redstone line, but all the next blocks still do; the first repeater turns off after some time and the 2nd block is not powered anymore... but the line is powered until the last block loses power.
If the signal is shorter than 4 ticks, this scheme won't work well, but buttons always give a 5-tick pulse and pressure plates' signal lasts at least 5 ticks.
And by the way, I used iron blocks, but these can be any non-transparent blocks,
Old answer
Or, for a different behavior, use an RS NOR Latch as in this screenshot.
This scheme will keep the pistons up for at least the time it takes the current to go through the repeaters, or for more time if the player keeps standing on the pressure plate.