REDSTONEPEDIA › Circuits › Pulse shapers
One pulse when switched off (falling-edge detector)
10-tick pulse · 5 blocks
When the input turns off, the output gives one short pulse of 10 ticks (0.5 s); turning the input on does nothing.
Footsteps and other noises don't set off its sculk sensor: the items in its chest set the one sound it listens to.
starts after 1 tick (0.05 s) · needs an input of at least 2 ticks (0.1 s) · made of calibrated sculk sensor, comparator, oak trapdoor · fits in 2×2×4
Every size 23
The best design for each size: pick one to see it.
| size | blocks | numbers |
|---|---|---|
| 1 tick (0.05 s) | 4 blocks | starts after 2 ticks (0.1 s) · needs an input of at least 2 ticks (0.1 s) |
| 2 ticks (0.1 s) | 2 blocks | starts after 4 ticks (0.2 s) · needs an input of at least 6 ticks (0.3 s) |
| 4 ticks (0.2 s) | 4 blocks | starts after 8 ticks (0.4 s) · needs an input of at least 6 ticks (0.3 s) |
| 6 ticks (0.3 s) | 4 blocks | starts after 10 ticks (0.5 s) · needs an input of at least 6 ticks (0.3 s) |
| 8 ticks (0.4 s) | 4 blocks | starts after 12 ticks (0.6 s) · needs an input of at least 6 ticks (0.3 s) |
| 10 ticks (0.5 s) (this page) | 5 blocks | starts after 1 tick (0.05 s) · needs an input of at least 2 ticks (0.1 s) |
| 12 ticks (0.6 s) | 16 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 14 ticks (0.7 s) | 16 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 16 ticks (0.8 s) | 13 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 18 ticks (0.9 s) | 16 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 20 ticks (1 s) | 20 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 22 ticks (1.1 s) | 20 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 24 ticks (1.2 s) | 13 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 26 ticks (1.3 s) | 20 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 28 ticks (1.4 s) | 20 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 30 ticks (1.5 s) | 20 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 32 ticks (1.6 s) | 13 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 36 ticks (1.8 s) | 24 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 38 ticks (1.9 s) | 24 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 40 ticks (2 s) | 13 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 64 ticks (3.2 s) | 13 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 128 ticks (6.4 s) | 13 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
| 256 ticks (12.8 s) | 13 blocks | starts after 6 ticks (0.3 s) · needs an input of at least 6 ticks (0.3 s) |
Try it
Hold IN under the view for a long press, tap it for a short one: the box marked OUT turns red while the output is on. Press play under the view to watch a demo on a loop; touch any other control to take over.
How this design does it: One 10-tick pulse (half a second) every time the input turns OFF, even after the shortest input (2 ticks), and footsteps or dropped items nearby never set it off: the input opens a trapdoor and closes it when it turns off, a calibrated sculk sensor (a sound sensor) switches on for exactly 10 ticks when it hears the trapdoor close, and a comparator reading a chest tunes the sensor to closing sounds only.
Build it
Download .litematic Download the design as text
The .litematic opens in Litematica (Minecraft 26.3): every block of the design in one region. The text file is the same build written as plain text, block by block.
Comes loaded with 988 cobblestone in its containers: the download includes them; building it by hand, put them in first.
Blocks used: calibrated sculk sensor chest comparator oak trapdoor stone
Details: how it works, measurements and properties
In depth
When the input turns off, the output gives one short pulse of L = 10 ticks (0.5 s), starting 1 tick (0.05 s) after the input turned off. When the input turns on, nothing happens. It handles every input pulse of 2 ticks (0.1 s) (the shortest a real input makes) or longer.
Use it to react to something stopping, e.g. a lever being switched back.
How to try it
Press play under the view to watch the demo on a loop (the badge reads demo with the step it is on; the same sequence is drawn as a timing diagram below). Touch any control to stop it and try the circuit yourself.
To try it: press and hold the IN button of the bar (or the cell tagged IN) to power that input; a quick tap sends a short 2-tick pulse.
Inputs are tagged in lime; the output is tagged OUT: the redstone lamp in that cell (the view adds it to show the output) lights while the output is on (the output strip by the demo badge shows its last 40 game ticks, 2 seconds). Drag to look around, pinch or scroll to zoom, step one game tick at a time with the step button.
Inputs and output over time
The input follows this schedule (the 3D view's demo plays the same). Lime: an input is on; orange: the output is on (taller = a stronger signal, 1 to 15). Time runs left to right in game ticks (20 ticks = 1 s).
Swipe the diagram sideways: the whole sequence lasts 648 ticks (32.4 s).
Step by step (12 lines)
in 2 ticks (0.1 s): +3 for 10 in 3 ticks (0.15 s): +4 for 10 in 4 ticks (0.2 s): +5 for 10 in 5 ticks (0.25 s): +6 for 10 in 6 ticks (0.3 s): +7 for 10 in 8 ticks (0.4 s): +9 for 10 in 10 ticks (0.5 s): +11 for 10 in 15 ticks (0.75 s): +16 for 10 in 20 ticks (1 s): +21 for 10 in 30 ticks (1.5 s): +31 for 10 in 40 ticks (2 s): +41 for 10 in 60 ticks (3 s): +61 for 10
Measurements
| metric | value | what it means |
|---|---|---|
| L | 10 ticks (0.5 s) | the length of the output pulse |
| delay | 1 tick (0.05 s) | the time from the input's edge to the start of the output pulse |
| min-pulse | 2 ticks (0.1 s) (the shortest a real input makes) | the shortest input pulse handled correctly (every longer one works too) |
| vibration-proof | yes |
Notes from its designer
One 10-tick pulse (half a second) every time the input turns OFF, even after the shortest input (2 ticks), and footsteps or dropped items nearby never set it off: the input opens a trapdoor and closes it when it turns off, a calibrated sculk sensor (a sound sensor) switches on for exactly 10 ticks when it hears the trapdoor close, and a comparator reading a chest tunes the sensor to closing sounds only. To build it: fill the chest with 988 items that stack to 64 (15 full stacks and 28 more), so the comparator gives 9 (the number shown over the chest in the 3D view). Good to know: the trapdoor clacks on every edge, and each clack is a vibration that sets off other sculk sensors within 16 blocks; the sensor still hears other machines' closing sounds within 16 blocks (a door or trapdoor closing, a piston pulling back, a lever or button switched off); "vibration-proof" means proof against players walking, jumping, dropping, placing and breaking blocks around it. The first falling-edge detector that sees the shortest inputs (2 ticks). Detail: a trapdoor emits block_open (frequency 10) and block_close (9); a calibrated sensor with a back signal accepts that frequency only (a lever's switch-off is 9 too, on the same edge).
Properties
| Study | Pulse shapers |
|---|---|
| Kind | One pulse when switched off (falling-edge detector) |
| Blocks placed | 5 (not counting the input levers or buttons and the lamp the view adds) |
| Box | 2×2×4 (16 blocks of space) |
| Made of (the blocks that change state) | calibrated sculk sensor, comparator, oak trapdoor |
| Inputs / outputs | IN (repeater) / OUT |
| Design file | pulse-fall-sculk-filter-L10 |
The design file
Design file (24 lines)
# One pulse when switched off: 10-tick pulse · 5 blocks
# https://vjeux.github.io/redstonepedia/circuits/pulse/pulse-fall-sculk-filter-L10.html
name: pulse-fall-sculk-filter-L10
circuit: falling-edge
origin: 0 0 0
port input: 0 0 0
port output: 3 0 1
palette:
T minecraft:oak_trapdoor[facing=north,half=bottom,open=false,powered=false,waterlogged=false]
K minecraft:calibrated_sculk_sensor[facing=north,power=0,sculk_sensor_phase=inactive,waterlogged=false]
C minecraft:comparator[facing=south,mode=compare,powered=false]
H minecraft:chest[facing=north,type=single,waterlogged=false]
S minecraft:stone
layer -1:
...
...
..S
...
layer 0:
.T.
..K
..C
..H
nbt: 2 0 3 {Items:[{Slot:0b,id:"minecraft:cobblestone",count:64},{Slot:1b,id:"minecraft:cobblestone",count:64},{Slot:2b,id:"minecraft:cobblestone",count:64},{Slot:3b,id:"minecraft:cobblestone",count:64},{Slot:4b,id:"minecraft:cobblestone",count:64},{Slot:5b,id:"minecraft:cobblestone",count:64},{Slot:6b,id:"minecraft:cobblestone",count:64},{Slot:7b,id:"minecraft:cobblestone",count:64},{Slot:8b,id:"minecraft:cobblestone",count:64},{Slot:9b,id:"minecraft:cobblestone",count:64},{Slot:10b,id:"minecraft:cobblestone",count:64},{Slot:11b,id:"minecraft:cobblestone",count:64},{Slot:12b,id:"minecraft:cobblestone",count:64},{Slot:13b,id:"minecraft:cobblestone",count:64},{Slot:14b,id:"minecraft:cobblestone",count:64},{Slot:15b,id:"minecraft:cobblestone",count:28}]}