REDSTONEPEDIA › Circuits › Timers and pulse multipliers
One-shot timer that restarts on every press (retriggerable monostable)
on for 36 ticks (1.8 s) · restarts on every press · 21 blocks
One press keeps the output on for 36 ticks (1.8 s); pressing again while it is on restarts the countdown.
starts after 4 ticks (0.2 s) · fits in 6×4×3
Every size 6
The best design for each size: pick one to see it.
| size | blocks | numbers |
|---|---|---|
| 12 ticks (0.6 s) | 26 blocks | starts after 4 ticks (0.2 s) |
| 16 ticks (0.8 s) | 25 blocks | starts after 4 ticks (0.2 s) |
| 20 ticks (1 s) | 22 blocks | starts after 4 ticks (0.2 s) |
| 32 ticks (1.6 s) | 21 blocks | starts after 4 ticks (0.2 s) |
| 36 ticks (1.8 s) (this page) | 21 blocks | starts after 4 ticks (0.2 s) |
| 116 ticks (5.8 s) | 36 blocks | starts after 10 ticks (0.5 s) |
Try it
Hold IN under the view for a long press, tap it for a short one: a tap keeps OUT red for a while; tap again while it is red and it stays red longer (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: Gives a 36-tick output pulse after each input pulse, and a new input restarts the 36 ticks: every input refills a small two-comparator loop that fades out on its own.
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: comparator copper bulb observer redstone wire stone
Details: how it works, measurements and properties
In depth
Each input pulse, however short, turns the output on for 36 ticks (1.8 s): a one-shot timer. It is retriggerable: another input pulse while the output is on restarts the count, so the output stays on while pulses keep coming and turns off 36 ticks (1.8 s) after the last one (a light that stays on while there is activity; inverted, an alarm for a clock that stopped).
The output turns on 4 ticks (0.2 s) after the input. It reacts to input pulses of 2 ticks (0.1 s) (the shortest a real input makes) or longer. Two presses at least 40 ticks (2 s) apart give two separate output pulses; closer together, the output just stays on longer.
How to try it
Press play under the view to watch the demo on a loop: single input pulses of 1 to 160 ticks (8 s) (each gives one output pulse of 36 ticks (1.8 s)), then pairs of short pulses closer and closer together: a second pulse while the output is on restarts the count, so the output turns off L after the second one. The badge reads demo with the step it is on, and 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: a tap keeps the output on for 36 ticks (1.8 s); tap again while it is on and it stays on 36 ticks (1.8 s) after your last tap.
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 2696 ticks (2 min 14.8 s).
Step by step (21 lines)
in 2 ticks (0.1 s): +4 for 36 in 3 ticks (0.15 s): +4 for 36 in 4 ticks (0.2 s): +4 for 36 in 5 ticks (0.25 s): +4 for 36 in 6 ticks (0.3 s): +4 for 36 in 8 ticks (0.4 s): +4 for 36 in 10 ticks (0.5 s): +4 for 36 in 15 ticks (0.75 s): +4 for 36 in 20 ticks (1 s): +4 for 36 in 30 ticks (1.5 s): +4 for 36 in 40 ticks (2 s): +4 for 36 in 80 ticks (4 s): +4 for 36 in 160 ticks (8 s): +4 for 36 second edge 6 ticks (0.3 s) after the first: +4 for 42 -> retriggerable second edge 8 ticks (0.4 s) after the first: +4 for 44 -> retriggerable second edge 10 ticks (0.5 s) after the first: +4 for 46 -> retriggerable second edge 12 ticks (0.6 s) after the first: +4 for 48 -> retriggerable second edge 16 ticks (0.8 s) after the first: +4 for 52 -> retriggerable second edge 20 ticks (1 s) after the first: +4 for 56 -> retriggerable second edge 24 ticks (1.2 s) after the first: +4 for 60 -> retriggerable second edge 32 ticks (1.6 s) after the first: +4 for 68 -> retriggerable
Measurements
| metric | value | what it means |
|---|---|---|
| L | 36 ticks (1.8 s) | the length of each output pulse, whatever the input's length |
| delay | 4 ticks (0.2 s) | game ticks from the input turning on to the output turning on |
| retrigger | retriggerable | retriggerable: a pulse while the output is on restarts L; non-retriggerable: it is ignored |
| re-arm | 40 ticks (2 s) | the shortest time between two presses that still gives two separate output pulses (closer presses restart the timer, or are ignored by a non-restarting one) |
| min-pulse | 2 ticks (0.1 s) (the shortest a real input makes) | the shortest input pulse handled correctly (every longer one works too) |
Notes from its designer
Gives a 36-tick output pulse after each input pulse, and a new input restarts the 36 ticks: every input refills a small two-comparator loop that fades out on its own. Unlike an item timer, a 2-tick press gives the whole length, in 2-tick steps, with no items to load back. Details: a copper bulb, a comparator and two observers turn each rising edge into 4 ticks of full-strength signal for the loop; 3 dust carry the signal back around, losing 2 per 4-tick lap, and the output reads the loop where the signal lasts longest. Longer pulses come from the two-loop family.
Properties
| Study | Timers and pulse multipliers |
|---|---|
| Kind | One-shot timer that restarts on every press (retriggerable monostable) |
| Blocks placed | 21 (not counting the input levers or buttons and the lamp the view adds) |
| Box | 6×4×3 (72 blocks of space) |
| Made of (the blocks that change state) | comparator, copper bulb, observer, redstone wire |
| Inputs / outputs | IN (repeater) / OUT |
| Design file | mono-retrig-ring-L36 |
The design file
Design file (31 lines)
# One-shot timer: on for 36 ticks (1.8 s) · restarts on every press · 21 blocks # https://vjeux.github.io/redstonepedia/circuits/pulsemult/mono-retrig-ring-L36.html name: mono-retrig-ring-L36 circuit: monostable retriggerable origin: -1 0 0 port input: 6 3 0 port output: -1 1 2 palette: S minecraft:stone d minecraft:redstone_wire[east=side,north=side,power=0,south=side,west=side] E minecraft:comparator[facing=east,mode=compare,powered=false] n minecraft:comparator[facing=north,mode=compare,powered=false] O minecraft:observer[facing=east,powered=false] U minecraft:observer[facing=up,powered=false] B minecraft:waxed_copper_bulb[lit=false,powered=false] layer 0: ..S.S... .S.S.... ..SS.... layer 1: .SESdS.. .n.d.... .Sdd.... layer 2: ...dOU.. ........ ........ layer 3: .....EB. ........ ........