User:Munin295/Pulse circuit

A pulse circuit is a redstone circuit which generates or modifies pulses.

Pulses
A pulse is a redstone signal turned on then off again.

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Most redstone components will respond to pulses of any length. However:
 * A redstone comparator will not respond to a 0.5-tick pulse.
 * A redstone torch will not respond to a pulse less than 2 ticks, but can be short-circuited into a 1-tick output.
 * A redstone torch repeatedly activated by a pulse cycle shorter than 5 ticks (for example, 2 ticks on, 2 ticks off) will "burn out" after 8 cycles (it will deactivate). A burnt-out redstone torch will not respond to inputs until at least 7 ticks of input inactivity has passed, or until it receives an update (either a random block update as part of the game tick's natural cycle, or a purposeful block update due to player, mob, or redstone activity).
 * A sticky piston activated by a 0.5 or 1-tick pulse will not pull on the pulse's falling edge a block it pushed on the pulse's rising edge (because the pushed block doesn't exist yet to be pulled), but can pull a block it didn't push on the pulse's rising edge.

Analyzing pulses
A pulse can be measured with 1-tick precision with an oscilloscope:


 * Oscilloscope


 * 1&times;N&times;2, flat, silent


 * An oscilloscope is used to analyze and diagnose pulses. It generally isn't built as part of a redstone mechanism, but is used in circuit invention, design and diagnosis to observe the length and spacing of pulses being generated by part of a circuit.


 * An oscilloscope simply consists of a line of 1-tick repeaters. 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 pulse 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 ), or
 * taking a screenshot with, 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 example, a 3.5-tick pulse may sometimes power 3 repeaters and sometimes 4 repeaters. 0.5-tick pulses do not vary between powering 0 or 1 repeaters (they just look like 1-tick pulses), but 0.5-tick and 1-tick pulses can be differentiated with a redstone comparator -- a 1-tick pulse will activate a comparator, but a 0.5-tick pulse will not.

Rising edge detector
A rising edge detector outputs a pulse when its input turns on (the rising edge of the input).


 * Circuit Breaker


 * 1&times;3&times;3 (9 block volume), 1-wide
 * circuit delay: 1 to 4 ticks, output pulse: 1 to 4 ticks
 * The circuit breaker is the most commonly used rising edge detector 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 1-tick activation pulse.


 * Dust-Cut Rising Edge Detector
 * features vary (see schematics)
 * A dust-cut rising edge detector works by moving a block so that it cuts the output dust line after only one tick.
 * Because of the output's fractional length, a 1-tick repeater may be needed to force a sticky piston to drop its block.


 * Subtraction Rising Edge Detector
 * features vary (see schematics)
 * A subtraction rising edge detector works by using the subtraction mode of a redstone comparator to shut off the output pulse.
 * Variations: Remove the final block and dust to increase the output pulse to 2 ticks.
 * Earliest Known Publication: 3 May 2013


 * Locked-Repeater Rising Edge Detector
 * features vary (see schematics)
 * Uses repeater locking to shut pulses off after 1 tick.
 * Variations: 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.


 * Dropper-Hopper Rising Edge Detector


 * 1&times;4&times;2 (8 block volume), 1-wide, 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: You can reduce the size of the circuit by putting the hopper on top of the dropper.


 * Moved-Block Rising Edge Detector
 * features vary (see schematics)
 * Uses the same principle as the circuit breaker -- power the output through a block, then remove the block to keep the output pulse short.
 * Earliest Known Publication: 14 March 2013 and 29 March 2013


 * NOR-Gate Rising Edge Detector
 * features vary (see schematics)
 * A NOR-gate rising edge detector 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.
 * All of these 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.

Inverted rising edge detector
An inverted rising edge detector is a circuit whose output is usually on, but which outputs an off-pulse on the input's rising edge.


 * OR-Gate Inverted Rising Edge Detector


 * 1&times;3&times;3 (9 block volume), 1-wide, silent
 * circuit delay: 1 tick, output pulse: 1 to 3 ticks (off-pulse)
 * An OR-gate inverted rising edge detector compares the current and previous input -- if the current input is on and the previous input was off, the output turns off for a brief period.
 * Earliest Known Publication: 1 June 2013


 * Moving-Block Inverted Rising Edge Detector


 * 1&times;4&times;3 (12 block volume), 1-wide, instant
 * circuit delay: 0 ticks, output pulse: 1.5 ticks (off-pulse)
 * This is a moving-block inverted dual edge detector with a repeater added to suppress the output on the falling edge.

Falling edge detector
A falling edge detector outputs a pulse when its input turns off (the falling edge of the input).


 * Moved-Block Falling Edge Detector


 * 1&times;3&times;3 (9 block volume), 1-wide
 * circuit delay: 1 tick, output pulse: 0.5 ticks
 * For some directions and input methods, the repeater may be needed to be set to 3 ticks to operate mechanism components.
 * Earliest Known Publication: 27 May 2013


 * Dust-Cut Falling Edge Detector


 * 1&times;4&times;3 (12 block volume), 1-wide
 * circuit delay: 0 ticks, output pulse: 2 ticks
 * When the input turns off, the piston immediately retracts the block, allowing the still-powered repeater to output a signal for 2 ticks. When the input turns on again, the piston cuts the connection before the signal can get through the repeater.


 * Locked-Hopper Falling Edge Detector


 * 1&times;4&times;2 (8 block volume), 1-wide, silent
 * circuit delay: 1 tick, output pulse: 4 ticks
 * When the input turns off, it takes 1 tick for the torch to turn back on, giving hopper A a chance to push its item to the right and activate the output.
 * This circuit requires time to reset (to push the item back into hopper A), so the fastest input clock it can handle is a 4-clock.
 * 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.
 * Earliest Known Publication: 22 May 2013


 * Locked-Repeater Falling Edge Detector


 * 2&times;3&times;2 (12 block volume), flat, silent
 * circuit delay: 2 ticks, output pulse: 1 tick
 * When the input turns on, the output repeater is locked before it can be powered by the block behind it. When the input turns off, the output repeater is unlocked and is briefly powered by the block behind it, producing a 1-tick output pulse.


 * NOR-Gate Falling Edge Detector
 * features vary (see schematics below)
 * A NOR-gate falling edge detector compares the current power to the power from 2 ticks ago -- if the current power is off and the previous power was on, the output torch flashes on briefly.
 * All of these 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.

Inverted falling edge detector
An inverted falling edge detector is a circuit whose output is usually on, but which outputs an off-pulse on the input's falling edge.


 * OR-Gate Inverted Falling Edge Detector


 * 1&times;4&times;4 (16 block volume), 1-wide, instant, silent
 * circuit delay: 0 ticks, output pulse: 1 tick (off-pulse)
 * The input goes straight through to the output, so when the input turns off, the output turns off until the torch can it back on again.


 * Locked-Repeater Inverted Falling Edge Detector


 * 2&times;3&times;2 (12 block volume), flat, silent
 * circuit delay: 2 ticks, output pulse: 1 tick (off-pulse)
 * When the input turns on, the output repeater is locked before it can turn off. When the input turns off, the output repeater is unlocked and is briefly un-powered by the block behind it, producing a 1-tick output off-pulse.

Dual edge detector
A dual edge detector outputs a pulse when its input changes (at either the rising edge or the falling edge of the input).


 * Moving-Block Dual Edge Detector


 * 1&times;4&times;3 (12 block volume), 1-wide
 * circuit delay: 1 tick, output pulse: 2 ticks


 * The block of redstone moves when the signal turns on and when it turns off. While it is moving it cannot power the dust below it, so the output torch turns on until the block of redstone stops moving.


 * Variations: The torch can be placed on the other side of the bottom blocks to get an output on the same side as the input. The piston and block of redstone can be moved to the side of the dust, rather than on top of the dust, producing a shorter but wider circuit.


 * Earliest Known Publication: 28 January 2013


 * Dust-Cut Dual Edge Detector


 * The simple version splits the difference between a rising edge detector and a falling edge detector to produce an output of 1 tick on each edge. The instant version adds an unrepeated rising edge detector to reduce the rising edge circuit delay to 0 ticks.




 * NOR-Gate Dual Edge Detector


 * 3&times;5&times;3 (45 block volume), silent
 * circuit delay: 3 ticks (rising edge) or 1 tick (falling edge), output pulse: 1 tick


 * A NOR-gate dual edge detector compares the current power to the power from 2 ticks ago -- if the current power is different than the previous power, an 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. Remove the blocks over the output torches to increase the output pulse to 2 ticks.


 * Earliest Known Publication: 2 July 2012


 * Locked-Repeater Dual Edge Detector


 * A locked-repeater dual edge detector uses the timing of repeater locking to detect signal edges.


 * Earliest Known Publication: 16 April 2013 and 1 May 2013



Inverted dual edge detector
An inverted dual edge detector is a circuit whose output is usually on, but which outputs an off-pulse when its input changes.


 * Moving-Block Inverted Dual Edge Detector


 * 1&times;3&times;3 (9 block volume), 1-wide, instant
 * circuit delay: 0 ticks, output pulse: 1.5 ticks (off-pulse)
 * Variations: The piston and block of redstone can be moved to the side of the dust, rather than on top of the dust, producing a flat 2-wide circuit.