REDSTONEPEDIA › Circuits › Pulse shapers

One pulse when switched on (rising-edge detector)

2-tick pulse · 2 blocks

When the input turns on, the output gives one short pulse of 2 ticks (0.1 s); turning the input off does nothing.

starts after 4 ticks (0.2 s) · needs an input of at least 6 ticks (0.3 s) · made of observer, sticky piston · fits in 1×3×1

2-tick pulseOne pulse when switched on3D view loading (or not available in this browser)

Every size 22

The best design for each size: pick one to see it.

sizeblocksnumbers
2 ticks (0.1 s) (this page)2 blocksstarts after 4 ticks (0.2 s) · needs an input of at least 6 ticks (0.3 s)
4 ticks (0.2 s)4 blocksstarts after 8 ticks (0.4 s) · needs an input of at least 4 ticks (0.2 s)
6 ticks (0.3 s)4 blocksstarts after 10 ticks (0.5 s) · needs an input of at least 4 ticks (0.2 s)
8 ticks (0.4 s)4 blocksstarts after 12 ticks (0.6 s) · needs an input of at least 4 ticks (0.2 s)
10 ticks (0.5 s)5 blocksstarts after 1 tick (0.05 s) · needs an input of at least 2 ticks (0.1 s)
12 ticks (0.6 s)17 blocksstarts after 8 ticks (0.4 s) · needs an input of at least 4 ticks (0.2 s)
14 ticks (0.7 s)17 blocksstarts after 10 ticks (0.5 s) · needs an input of at least 4 ticks (0.2 s)
16 ticks (0.8 s)13 blocksstarts after 6 ticks (0.3 s) · needs an input of at least 4 ticks (0.2 s)
18 ticks (0.9 s)17 blocksstarts after 6 ticks (0.3 s) · needs an input of at least 4 ticks (0.2 s)
20 ticks (1 s)20 blocksstarts after 6 ticks (0.3 s) · needs an input of at least 4 ticks (0.2 s)
22 ticks (1.1 s)20 blocksstarts after 6 ticks (0.3 s) · needs an input of at least 4 ticks (0.2 s)
24 ticks (1.2 s)13 blocksstarts after 6 ticks (0.3 s) · needs an input of at least 4 ticks (0.2 s)
26 ticks (1.3 s)20 blocksstarts after 6 ticks (0.3 s) · needs an input of at least 4 ticks (0.2 s)
28 ticks (1.4 s)20 blocksstarts after 6 ticks (0.3 s) · needs an input of at least 4 ticks (0.2 s)
30 ticks (1.5 s)20 blocksstarts after 6 ticks (0.3 s) · needs an input of at least 4 ticks (0.2 s)
32 ticks (1.6 s)13 blocksstarts after 6 ticks (0.3 s) · needs an input of at least 4 ticks (0.2 s)
36 ticks (1.8 s)24 blocksstarts after 6 ticks (0.3 s) · needs an input of at least 4 ticks (0.2 s)
38 ticks (1.9 s)24 blocksstarts after 6 ticks (0.3 s) · needs an input of at least 4 ticks (0.2 s)
40 ticks (2 s)13 blocksstarts after 6 ticks (0.3 s) · needs an input of at least 4 ticks (0.2 s)
64 ticks (3.2 s)13 blocksstarts after 6 ticks (0.3 s) · needs an input of at least 4 ticks (0.2 s)
128 ticks (6.4 s)13 blocksstarts after 6 ticks (0.3 s) · needs an input of at least 4 ticks (0.2 s)
256 ticks (12.8 s)13 blocksstarts after 6 ticks (0.3 s) · needs an input of at least 4 ticks (0.2 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: The smallest rising-edge detector, 2 blocks: a sticky piston lifts an observer when the input turns on, and the observer fires once as it lands, into the cell behind it (the output, a 2-tick pulse); pulled back down when the input turns off, it fires under the output, into nothing.

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.

Blocks used: observer sticky piston

Details: how it works, measurements and properties

In depth

When the input turns on, the output gives one short pulse of L = 2 ticks (0.1 s), starting 4 ticks (0.2 s) after the input turned on. When the input turns off, nothing happens. It handles every input pulse of 6 ticks (0.3 s) or longer.

Use it to turn a lever (which stays on) into a single short pulse, e.g. to fire a piston once.

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).

a 30-tick inputa 40-tick inputINOUTticks020406080100120140160180200220240260280300320340360380400

Swipe the diagram sideways: the whole sequence lasts 425 ticks (21.25 s).

Step by step (11 lines)
in  2 ticks (0.1 s): +4 for 2
in  3 ticks (0.15 s): no output  <- not handled
in  4 ticks (0.2 s): no output  <- not handled
in  5 ticks (0.25 s): +4 for 1  <- not handled
in  6 ticks (0.3 s): +4 for 2
in  8 ticks (0.4 s): +4 for 2
in 10 ticks (0.5 s): +4 for 2
in 15 ticks (0.75 s): +4 for 2
in 20 ticks (1 s): +4 for 2
in 30 ticks (1.5 s): +4 for 2
in 40 ticks (2 s): +4 for 2

Measurements

metricvaluewhat it means
L2 ticks (0.1 s)the length of the output pulse
delay4 ticks (0.2 s)the time from the input's edge to the start of the output pulse
min-pulse6 ticks (0.3 s)the shortest input pulse handled correctly (every longer one works too)
tileableevery 2 (2 0 0)

Notes from its designer

The smallest rising-edge detector, 2 blocks: a sticky piston lifts an observer when the input turns on, and the observer fires once as it lands, into the cell behind it (the output, a 2-tick pulse); pulled back down when the input turns off, it fires under the output, into nothing. Copies stand side by side every 2 blocks. Detail: inputs of 6 ticks or more.

Properties

StudyPulse shapers
KindOne pulse when switched on (rising-edge detector)
Blocks placed2 (not counting the input levers or buttons and the lamp the view adds)
Box1×3×1 (3 blocks of space)
Made of (the blocks that change state)observer, sticky piston
Inputs / outputsIN (repeater) / OUT
The same build is alsoat most 2 ticks (0.1 s) · 2 blocks (the same blocks, listed as another kind)
Design filepulse-rising-edge-piston-observer-L2

The design file

on GitHub

Design file (15 lines)
# One pulse when switched on: 2-tick pulse · 2 blocks
# https://vjeux.github.io/redstonepedia/circuits/pulse/pulse-rising-edge-piston-observer-L2.html
name: pulse-rising-edge-piston-observer-L2
circuit: rising-edge
tile: 2 0 0
port input: 0 0 1
port output: 0 2 -1
origin: 0 0 0
palette:
  O minecraft:observer[facing=south,powered=false]
  S minecraft:sticky_piston[extended=false,facing=up]
layer 0:
  S
layer 1:
  O