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A pulse circuit is a redstone circuit See redstone circuits. For other redstone-related articles, see Redstone (disambiguation). Contents 1 Redstone basics 1.1 Redstone components 1.2 Power 1.3 Power level 1.4 Redstone update 1.5 Redstone tick 1.6 Signals and pulses which generates, modifies, detects, or otherwise operates on redstone pulses.
- See also: Clock circuit
Pulses
A pulse is a temporary change in redstone power that eventually reverts to its original state.
An on-pulse is when a redstone signal turns on, then off again. On-pulses are usually just called "pulses" unless there is a need to differentiate them from off-pulses.
An off-pulse is when a redstone signal turns off, then on again.
The pulse length of a pulse is how long it lasts. Short pulses are described in redstone ticks (for instance, a "3-tick pulse" for a pulse that turns off 0.3 seconds after it turns on) while longer pulses are measured in any convenient unit of time (for instance, a "3-second pulse").
The rising edge of a pulse is when the power turns on ⃢₀ₓ the beginning of an on-pulse or the end of an off-pulse.
The falling edge of a pulse is when the power turns off ⃢₀ₓ the end of an on-pulse or the beginning of an off-pulse.
Videos
Pulse interactions
Some redstone components react differently to short pulses:
- A piston Piston Transparency Yes Luminance None Blast resistance 2.5 Tool Any tool Renewable Yes Stackable Yes (64) Flammable No Drops Itself Data values See Data values Pistons are blocks capable of pushing most blocks, depending on or sticky piston usually takes 1.5 ticks to extend. If the activation pulse ends before this (because it`s only 0.5 ticks or 1 tick long), the piston or sticky piston will "abort" ⃢₀ₓ it will place the pushed blocks at their pushed position and return to its retracted state instantly. This can cause sticky pistons to "drop" their block ⃢₀ₓ they push a block and then return to their retracted state without pulling it back.
- A redstone comparator Redstone Comparator Transparency Yes Luminance No (7 when powered, in Pocket Edition) Blast resistance 0 Tool Any tool Renewable No Stackable Yes (64) Flammable No Drops Redstone Comparator (1) Data values See Data values Name will not transmit a half-tick pulse, only pulses with durations of 1 tick or more.
- A redstone lamp Redstone Lamp Transparency Partial (when on) Luminance Yes, 15 (when on) Blast resistance 1.5 Tool Any tool Renewable Yes Stackable Yes (64) Flammable No Drops Itself Data values See Data values Name See Data values cannot be deactivated by an off-pulse shorter than 2 ticks.
- A redstone repeater Redstone Repeater Transparency Yes (partial) Luminance No (7 when powered, in Pocket Edition) Blast resistance 0 Tool Any tool Renewable Yes Stackable Yes (64) Flammable No Availability Survival, Creative Drops Redstone Repeater (1) Data values will increase the length of pulses which are shorter than its delay to match its delay (for instance, a 4-tick repeater will change any pulse shorter than 4 ticks into a 4-tick pulse).
- A redstone torch Redstone Torch Transparency Yes Luminance Yes, 7 (when on) Blast resistance 0 Tool Any tool Renewable Yes Stackable Yes (64) Flammable No Drops Itself Data values See Data values Name See Data values This article cannot be deactivated by a pulse shorter than 1.5 ticks.
Pulse analysis
When building circuits, it can sometimes be helpful to observe the pulses being produced to confirm their duration or spacing.
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A pulse can be measured with 1-tick precision with an oscilloscope (see schematic, right).
An oscilloscope simply consists of a line of 1-tick repeaters (aka a "racetrack"). An oscilloscope should be constructed to be at least as long as the expected pulse, plus a few extra repeaters (the more repeaters, the easier it will be to time capturing a pulse). For periodic pulses (as from clock circuits), an oscilloscope should be at least as long as the clock period (both the on and off parts of the pulse).
An oscilloscope can be frozen to aid reading by:
- positioning the oscilloscope on the screen so that it can be viewed when the player escapes to the game menu (by default, with esc), or
- taking a screenshot with F2, or
- running repeaters into the side of the oscilloscope and powering them simultaneously to lock the repeaters of the oscilloscope.
An oscilloscope is not capable of displaying fractional-tick pulses directly (0.5-tick pulses, 1.5-tick pulses, etc.), but for fractional-tick pulses greater than 1 tick, the pulse length may appear to change as it moves through the oscilloscope. For instance, a 3.5-tick pulse may sometimes power 3 repeaters and sometimes 4 repeaters.
Half-tick pulses do not vary between powering 0 or 1 repeaters (they just look like 1-tick pulses), but half-tick and 1-tick pulses can be differentiated with a redstone comparator Redstone Comparator Transparency Yes Luminance No (7 when powered, in Pocket Edition) Blast resistance 0 Tool Any tool Renewable No Stackable Yes (64) Flammable No Drops Redstone Comparator (1) Data values See Data values Name – a 1-tick pulse can activate a comparator, but a half-tick pulse cannot.
Multiple oscilloscopes can be laid in parallel to compare different pulses. For instance, you can determine a circuit`s delay by putting the circuit`s input signal through one oscilloscope and the circuit`s output through another and counting the difference between the input and output signal edges.
Oscilloscopes are useful but sometimes require you to be in an inconvenient position to observe them. If you just need to observe the simultaneity of multiple pulses it can be useful to use pistons or note blocks and observe their movement or note particles from any angle. Redstone lamps are less useful for this purpose because they take 2 ticks to turn off.
Monostable circuit
A circuit is monostable if it has only one stable output state ("mono-" means "one", so "monostable" means "one stable state").
A circuit`s output can be powered or unpowered. If an output stays in the same state until the circuit is triggered again, that output state is called "stable". An output state which will change without the input being triggered is not stable (that doesn`t necessarily mean it`s random ⃢₀ₓ it may be an intentional change after a designed delay).
If a circuit has only one stable output state then the circuit is called "monostable". For instance, if a powered state will inevitably revert to the unpowered state, but the unpowered state won`t change until the input is triggered.
When someone says "monostable circuit" in Minecraft, they usually mean a pulse generator or a pulse limiter. Be that as it may, any redstone circuit which produces a finite number of pulses is technically a monostable circuit (all the circuits in this article, in fact, as well as some others), so instead of saying monostable circuit, it can be helpful to be more specific:
- A pulse generator generates a pulse
- A pulse limiter reduces the duration of long pulses
- A pulse extender increases the length of short pulses
- A pulse multiplier produces multiple output pulses in response to a single input pulse
- A pulse divider produces an output pulse after a specific number of input pulses
- An edge detector produces an output pulse when it detects a specific edge of an input pulse
- A pulse length detector produces an output pulse when it detects an input pulse of a specific length
- A block update detector See the redstone circuit. For the block, see Observer. The Block Update Detector, or "BUD switch", is a redstone mechanism that uses quirks in the game in order to detect changes in produces an output pulse when a specific block is updated (for instance, stone is mined, water turns to ice, etc.)
- A comparator update detector The Comparator Update Detector, or "CUD switch", is a redstone mechanism that exploits a bug in the game in order to detect comparator updates. Comparator updates are updates that only update comparators, for instance, interacting produces an output pulse when a specific comparator is updated by an inventory update
Clock circuits See a specific category of redstone circuits. For the item, see Clock. For other circuits, see redstone circuit. A clock circuit is a redstone circuit which produces a clock signal: a pattern also produce pulses, but they aren`t monostable because they have no stable output states (they are "astable") unless forced into one by external interference (for instance, when they`re turned off). Logic See a specific category of redstone circuits. For other circuits, see redstone circuit. A logic gate can be thought of as a simple device that will return a number of outputs, determined and memory circuits See a specific category of redstone circuits. For other circuits, see redstone circuits. Note: This page uses many schematics, which are loaded individually for performance reasons. Schematic Help] Contents 1 Introduction 2 RS aren`t monostable because both of their output states are stable (they are "bistable") ⃢₀ₓ they won`t change unless triggered by their input.
- See also: Wikipedia:Monostable
Pulse generator
A pulse generator (aka "pulsegen") creates an output pulse when triggered.
Most pulse generators consist of a switch Redstone components are the blocks used to build redstone structures. Redstone components include power components (such as redstone torchs, buttons, and pressure plates), transmission components (such as redstone dust and redstone repeaters), and mechanism components (button, lever, etc.) and a pulse limiter, but a switch could also be added to a pulse extender to generate a longer pulse.
Schematic Gallery: Pulse Generator
- Circuit Breaker Pulse Generator
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- 1⃗3⃗3 (9 block volume), 1-wide
- circuit delay: 1 tick
- output pulse: 1 tick
- The circuit breaker is the most commonly used pulse generator due to its small size and adjustable output.
- Variations: The output repeater may be set to any delay, which will also lengthen the output pulse to equal the delay. When oriented north-south, the output repeater may be replaced by any mechanism component, causing the mechanism component to receive a 0.5-tick activation pulse.
- Dust-Cut Pulse Generator
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- 1⃗4⃗3 (12 block volume), 1-wide
- circuit delay: 0 ticks
- output pulse: 1.5 ticks
- A dust-cut pulse generator limits the output pulse by moving a block so that it cuts the output dust line.
- NOR-Gate Pulse Generator
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- 1⃗4⃗3 (12 block volume), 1-wide, silent
- circuit delay: 2 ticks
- output pulse: 1 tick
- A NOR-gate pulse generator compares the current power to the power from 2 ticks ago – if the current power is on and the previous power was off, the output torch flashes on briefly.
- This design uses a trick to limit the output pulse to a single tick. A redstone torch cannot be activated by a 1-tick pulse from exterior sources, but a torch activated by a 2-tick exterior pulse can short-circuit itself into a 1-tick pulse. To increase the output pulse to 2 ticks, remove the block over the output torch. To then increase it to 3 ticks, increase the delay on the repeater to 4 ticks.
- Locked-Repeater Pulse Generator
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- 2⃗3⃗2 (12 block volume), flat, silent
- circuit delay: 2 ticks
- output pulse: 1 tick
- When the lever is turned off, the locked repeater allows a pulse through.
- Variations: The locked repeater can be set to any delay. This increases the output pulse length, but also the circuit delay.
Off-pulse generator
An off-pulse generator has an output which is usually on, but generates an off-pulse when triggered.
- OR-Gate Off-Pulse Generator
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- 1⃗3⃗3 (9 block volume), 1-wide, silent
- circuit delay: 1 tick
- output pulse: 1 tick (off)
- When triggered, the bottom torch turns off, but the top torch doesn`t turn on until 1 tick later, allowing a 1-tick off-pulse output.
Pulse limiter
A pulse limiter (aka "pulse shortener") reduces the length of a long pulse.
An ideal pulse limiter would allow shorter pulses through unchanged, but in practice the range of input pulse can often be determined (or guessed) and it is sufficient to use a circuit which produces a specific pulse shorter than expected input pulses.
Any rising edge detector can also be used as a pulse limiter.
Schematic Gallery: Pulse Limiter
- Circuit Breaker Pulse Limiter
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- 1⃗3⃗3 (9 block volume), 1-wide
- circuit delay: 1 tick
- output pulse: 1 tick
- The circuit breaker is the most commonly used pulse limiter due to its small size and adjustable output.
- Variations: The output repeater may be set to any delay, which will also lengthen the output pulse to equal the delay. When oriented north-south, the output repeater may be replaced by any mechanism component, causing the mechanism component to receive a 0.5-tick activation pulse.
- Dust-Cut Pulse Limiter
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- 1⃗5⃗3 (15 block volume), 1-wide, instant
- circuit delay: 0 ticks
- output pulse: 1.5 ticks
- A dust-cut pulse limiter limits the output pulse by moving a block so that it cuts the output dust line.
- The dust-cut pulse limiter doesn`t "repeat" its input (boost it back up to full power), so a repeater may be needed before or after it (adding delay).
- The dust-cut pulse limiter is an "ideal" pulse limiter (see above). Pulses shorter than 1.5 ticks (its maximum output pulse) will be allowed through unchanged.
- Moved-Block Pulse Limiter
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- 3⃗3⃗2 (18 block volume), flat
- circuit delay: 1 tick
- output pulse: 1 tick
- Uses the same principle as the circuit breaker pulse limiter – power the output through a block, then remove the block to keep the output pulse short.
- Variations: The bottom repeater can be set to a longer delay to produce output pulses of 2 or 3 ticks.
- NOR-Gate Pulse Limiter
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- features vary (see schematics)
- A NOR-gate pulse limiter compares the current power to the power from 2 ticks ago – if the current power is on and the previous power was off, the output torch flashes on briefly.
- The "1-wide" and "1-tick" designs use a trick to limit the output pulse to a single tick. A redstone torch cannot be activated by a 1-tick pulse from exterior sources, but a torch activated by a 2-tick exterior pulse can short-circuit itself into a 1-tick pulse. Remove the block over an output torch to increase the output pulse to 2 ticks.
- Locked-Repeater Pulse Limiter
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- 2⃗4⃗2 (16 block volume), flat, silent
- circuit delay: 3 ticks
- output pulse: 1 tick
- Uses repeater locking to shut pulses off after 1 tick.
- Variations: The output repeater can set to any delay. This increases the output pulse, but also increases the circuit delay.
- If the input doesn`t have to be at the same height as the output, you can move the torch so that it`s attached to the top of the block it`s currently above, and run the input into that block (making the circuit only 2⃗3⃗2).
- Dropper-Hopper Pulse Limiter
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- 1⃗4⃗2 (8 block volume), 1-wide, flat, silent
- circuit delay: 3 ticks
- output pulse: 3.5 ticks
- When the input turns on, the dropper pushes an item into the hopper, activating the comparator until the hopper pushes the item back.
- The initial block is required to activate the dropper without powering it (which would deactivate the adjacent hopper, preventing it from returning the item to turn off the output pulse).
- Because the output comes from a comparator used as an inventory counter, the output power level will only be 1 (with a stackable item) or 3 (with a non-stackable item) – add a repeater for a higher power level output.
- Variations: If the input and output don`t need to be at the same height, you can reduce the size of the circuit by putting the hopper on top of the dropper (making the circuit 1⃗3⃗2).
Off-pulse limiter
An off-pulse limiter (aka "inverted pulse limiter") has an output which is usually on, but which shortens the length of long off-pulses.
Any inverted falling edge detector can also be used as an off-pulse limiter.
- OR-Gate Off-Pulse Limiter
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- features vary (see schematics)
- An or-gate off-pulse limiter combines the input with a delayed inverted input to limit off-pulses.
- The "instant" version doesn`t repeat its input (boost it back up to full power), so a repeater may be needed before or after it (adding delay).
- Variations: The bottom repeater of the flat version can be adjusted to any delay, increasing the length of the off-pulse to match the repeater`s delay (this doesn`t actually increase the circuit delay).
- The bottom redstone dust in the "instant" version can be replaced with a repeater to increase the length of its off-pulse.
- Moving-Block Off-Pulse Limiter
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- 1⃗4⃗2 (8 block volume), 1-wide, instant
- circuit delay: 0 ticks
- output pulse: 2.5 ticks (off)
- When the input turns off, the piston begins to retract. 1 tick later, the torch turns on, which re-activates the sticky piston by quasi-connectivity, causing it to extend again.
- Ground Instant Off-Pulse Limiter
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- 2⃗5⃗2 (20 block volume), instant
- circuit delay: 0 ticks
- output pulse: 0-0.5 ticks (off)
- The redstone block keeps the circuit powered while off. Powering the circuit moves the redstone block, but apparently the game interprets the power as still being on, so the result is a 0-tick off-pulse. Removing power from the circuit pulls the redstone block back into place, which results in a 0.5-tick off-pulse. This circuit pulses too quickly for torches or repeaters.
Pulse extender
A pulse extender (aka "pulse sustainer", "pulse lengthener") increases the duration of a pulse.
The most compact options are:
- Up to 4 ticks: Repeater
- Up to 8 ticks: Repeater-Line Pulse Extender
- 1 second to 4 minutes: Dropper-Latch Pulse Extender or Hopper-Clock Pulse Extender
- 5 minutes to 81 hours: MHDC Pulse Extender
Note: Dropper and hopper designs will start counting down the first time they get a pulse, where as repeater and comparator designs restart the count down each time a pulse is received.
Schematic Gallery: Pulse Extender
- Redstone Repeater
- 1⃗1⃗2 (2 block volume)
- 1-wide, flat, silent
- circuit delay: 1 to 4 ticks
- output pulse: 1 to 4 ticks
- For any input pulse shorter than its delay, a redstone repeater Redstone Repeater Transparency Yes (partial) Luminance No (7 when powered, in Pocket Edition) Blast resistance 0 Tool Any tool Renewable Yes Stackable Yes (64) Flammable No Availability Survival, Creative Drops Redstone Repeater (1) Data values will increase the duration of the pulse to match its delay. For instance, a 3-tick repeater will turn a 1-tick pulse or a 2-tick pulse into a 3-tick pulse.
- Additional repeaters will only delay the pulse, not extend it (but see the repeater-line pulse extender below).
- Repeater-Line Pulse Extender
- 2⃗N⃗2
- flat, silent, instant
- circuit delay: 0 ticks (instant) or 4 ticks (delayed)
- output pulse: up to 4 ticks per repeater
- For the instant version, the input must be a pulse at least as long as the longest-delay repeater in the line (usually 4 ticks) – if not, use the delayed version.
- Dropper-Latch Pulse Extender
- 2⃗6⃗2 (24 block volume)
- flat, silent
- circuit delay: 5 ticks
- output pulse: 5 ticks to 256 seconds
- Each item in the middle hopper adds 8 ticks (0.8 seconds) to the output pulse. The output pulse can be fine-tuned by increasing the delay on the 1-tick repeater by up to 3 ticks, decreasing the delay on the 4-tick repeater by up to 3 ticks, or by replacing the 4-tick repeater with a block to decrease the delay by 4 ticks (these adjustments affect the total pulse duration, not per item, allowing pulse durations of any tick amount from 5 ticks to 256 seconds).
- Variations: If the input pulse might be longer than half the output pulse, add a block before the dropper to keep it from deactivating the hopper. A 1-wide version is possible by using two droppers (but only adjustable in increments of 8 ticks):
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- Hopper-Clock Pulse Extender
- features vary (see schematics)
- circuit delay: 1 tick
- output pulse: 4 ticks to 256 seconds
- A hopper-clock pulse extender is a hopper clock with one of the sticky pistons replaced with a regular piston so that it won`t pull the block of redstone back, but instead wait for the input to trigger a new clock cycle.
- A hopper-clock pulse extender with a single item in its hoppers produces a 4-tick output pulse. Each additional item adds 8 ticks to the output pulse (unlike the dropper-latch pulse extender, the output of a hopper-clock pulse extender can only be adjusted in 8-tick increments).
- While waiting for the input to turn on, the sticky piston is actually in a state where it is powered but doesn`t know it (like a stuck-piston BUD circuit) until "woken up" by the input changing its power level. This will only work as long as the input power level is different than the resting output of the powered comparator (unintuitively, it will even work if the input power level is less than the comparator output). In addition, any other block update or nearby redstone update can trigger the powered sticky piston, so care should be taken to keep other circuit activity away from the sticky piston.
- Earliest Known Publication: 4 May 2013 (based on the ethonian hopper clock)
- RS Latch Pulse Extender
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- features vary (see schematics)
- output pulse: up to 8 ticks per repeater
- An RS latch pulse extender works by setting the output on with a latch, then resetting the latch after some delay.
- Both of the circuits below use a trick to double the delay produced by the repeaters, by first powering the output from the latch, then from the repeaters. This means that any 1-tick adjustment to the repeater loop will produce a 2-tick adjustment in the output pulse.
- Fader Pulse Extender
- 2⃗N⃗2
- flat, silent
- circuit delay: 0 ticks
- output pulse: up to 14 ticks per comparator
- The delay depends on the input`s signal strength – for input signal strength S, the delay will be (S-1) ticks per comparator. The signal strength of the output will gradually decay, so should usually be boosted with a repeater.
- MHC Pulse Extender
- 6⃗6⃗2 (72 block volume)
- flat
- circuit delay: 3 ticks
- output pulse: up to 22 hours
- "MHC" stands for "multiplicative hopper clock" (a hopper counter multiplies the clock period of a hopper clock).
- When the input turns on, the torch will turn off, allowing both clocks to cycle into a state where the bottom clock will continue to hold the torch off until it`s completed one full cycle. The number of items in the top hoppers determines the top clock`s cycle period, and its block of redstone will move every half-cycle, allowing the bottom clock to move one item.
- The half-cycle is equal to the number of items in the top hoppers times 4 ticks (or 0.4 seconds per item) – up to 128 seconds for 320 items. The bottom clock will keep the output on for a number of half-cycles equal to twice the number of items in the bottom hoppers, minus 1. Thus, the output pulse equals 0.4 seconds ⃗
⃗ (2 ⃗ - 1).
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Items Required for Useful Output Pulses Output Pulse Items in top hoppers Items in bottom hoppers 5 minutes 150 3 10 minutes 300 3 15 minutes 150 8 20 minutes 200 8 30 minutes 300 8 1 hour 200 23 90 minutes 300 23 2 hours 240 38 3 hours 200 68 4 hours 288 63 6 hours 240 113 12 hours 288 188
- MHDC Pulse Extender
- 5⃗7⃗2 (70 block volume)
- flat
- circuit delay: 5 ticks
- output pulse: up to 81 hours
- "MHDC" stands for "multiplicative hopper-dropper clock" (a dropper counter multiplies the clock period of a hopper clock).
- When the input turns on, the torch will turn off, allowing both clocks to cycle into a state where the bottom clock will continue to hold the torch off until it`s completed one full cycle. The hoppers can hold up to 320 items (X) and the droppers can hold up to 576 items (Y). The duration of the output pulse will be X ⃗ (2Y-1) ⃗ 0.8 seconds.
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Items Required for Useful Output Pulses Output Pulse Items in hoppers Items in droppers 5 minutes 125 2 10 minutes 250 2 15 minutes 225 3 20 minutes 300 3 30 minutes 250 5 1 hour 300 8 90 minutes 270 13 2 hours 200 23 3 hours 300 23 4 hours 144 63 6 hours 216 63 12 hours 240 113 24 hours 288 188 48 hours 320 338 72 hours 288 563
- Cooldown Pulse Extender
| Note: This circuit uses command blocks Command Block Type Block Entity Physics No Transparency No Luminance No Blast resistance 18,000,000 Hardness -1 Tool None Renewable No Stackable Yes (64) Flammable No First appearances See history Drops None Block entity id command_block which cannot be obtained legitimately in survival A new Survival game of Minecraft. The health and hunger bars, as well as the hotbar, are visible. See the game mode. For other uses, see Survival (disambiguation). Survival mode is one mode. This circuit is intended for server ops and adventure map builds. |
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