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Redstone Repeater

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Redstone Repeater
Redstone (Repeater, Inactive).gif
Redstone (Repeater, Active).gif
Redstone Repeater
Type

Solid block

Requirements

Support block

Physics

No

Transparency

Yes (partial)

Luminance

No

Blast resistance

0

Hardness

0

Tool

Any tool

Renewable

Yes

Stackable

Yes (64)

Flammable

No

Availability

Survival, Creative

First appearance

Beta 1.3

Drops

Itself

Data values

See Data values

Name

See Data values

A redstone repeater is a block used in redstone circuits to "repeat" redstone signals back to full strength, delay signals, prevent signals moving backwards, or to "lock" signals in one state.

Obtaining[edit]

A redstone repeater can be obtained by crafting, by looting jungle temples, or by breaking a previously-placed repeater.

Breaking[edit]

A redstone repeater can be broken instantly using any tool, or without a tool, and drops itself as an item. To remove a redstone repeater, mine it.

A redstone repeater will also be removed and drop itself as an item:

  • if its attachment block is moved, removed, or destroyed
  • if water flows into its space
  • if a piston tries to push it or moves a block into its space

If lava flows into a redstone repeater's space, the redstone repeater will be destroyed without dropping itself as an item.

Crafting[edit]

Ingredients Crafting recipe

Redstone Torch +
Redstone +
Stone




Grid layout Arrow (small).png Redstone Repeater
Redstone Torch Redstone Redstone Torch
Stone Stone Stone

Natural generation[edit]

A redstone repeater generated in the jungle temple's hidden room.

A single redstone repeater is generated naturally in each jungle temple.

Usage[edit]

See also: Redstone circuit

A redstone repeater can be used to "repeat" redstone signals back to full strength, delay signals, prevent signals moving backwards, or to "lock" signals in one state

A repeater can only be placed on opaque blocks (dirt, stone, etc., but not glass, leaves, etc.), or on top of upside-down slabs, upside-down stairs, and hoppers. To place a repeater, use the Place Block control.

A redstone repeater has a front and back – the arrow on the top points to the repeater's front. A repeater also has two small redstone torches on its top – the color of the torches indicates whether its output is on (dark red when off, bright red when on) and the distance between them indicates the delay the repeater adds to the signal transmission.

A repeater is 0.125 (1/8) blocks high.

Signal transmission[edit]

A repeater only transmits signals from its back to its front, but its behavior can be modified from the side (see signal locking, below).

Different ways to power a repeater

A redstone repeater can be powered by any of the following components at its back:

A redstone repeater can power any of the following components at its front:

  • redstone dust
  • a redstone comparator or another redstone repeater facing away from the repeater
  • a mechanism component (such as pistons, doors, etc.)
  • an opaque block

An opaque block powered by a redstone repeater is called "strongly-powered" (as opposed to an opaque block "weakly-powered" by redstone dust). A strongly-powered opaque block can power adjacent redstone dust, as well as other redstone components.

Signal repeating[edit]

A redstone repeater can "repeat" a redstone signal, boosting it back up to power level 15.

Redstone signals have a maximum power level of 15 and that level drops by 1 for every block of redstone dust the signal travels through. If a signal must travel through more than 15 blocks of redstone dust, a redstone repeater can be used to boost the signal back up to full strength. An extra two blocks of distance can be achieved by placing solid opaque blocks before and after the repeater.

While redstone repeaters can allow signals to travel great distances, each adds some delay to the transmission. An alternative is an instant repeater circuit (aka Instawire) which allows distance transmission with no delay.

Signal delay[edit]

When initially placed, a redstone repeater has a delay of 1 redstone tick (equivalent to 2 game ticks, or 0.1 seconds barring lag).

A repeater's delay can be modified by using the Use Item control. Each use increases the repeater's delay by 1 redstone tick, to a maximum of 4 redstone ticks, then back to 1 redstone tick. Longer delays can be made with multiple repeaters – for example, a repeater set to '4' and another to '1' will give a half second delay (0.4s + 0.1s = 0.5s).

A repeater set to a delay of 2 to 4 redstone ticks will increase the length of any shorter on-pulse to match the length of the repeater's delay, and suppress any shorter off-pulse. For example, a repeater set to a 4-tick delay will change a 1-tick, 2-tick, or 3-tick on-pulse into a 4-tick on-pulse, and will not allow through any off-pulse shorter than 4 ticks.

Signal direction[edit]

A redstone repeater acts as a "diode" – it will only allow redstone signals through in one direction (unlike redstone dust or opaque blocks which can transmit redstone signals in any direction).

A diode can be used to protect a redstone circuit from redstone signals feeding back into the circuit from its output, or can be used to isolate one part of a circuit from another.

Alternative diodes include redstone comparators and transparent diodes.

Signal locking[edit]

The left repeater has been locked in an unpowered output state by the right repeater.

A redstone repeater can be "locked" by another powered redstone repeater facing its side. When locked, the repeater will not change its output (whether powered or unpowered), no matter what the input does. When the side repeater turns back off, the repeater will go back to its normal behavior.

A repeater can also be locked by a powered redstone comparator facing its side. This offers additional possibilities for locking signals because a comparator's output can be affected from 3 sides as well as by containers.

While a repeater is locked by another repeater (but not by a comparator), the small movable redstone torch on top will change into a bedrock bar, indicating its locked status.

If a repeater is locked again too quickly after unlocking (e.g. the lock is controlled by a fast clock circuit), or the lock and the input are changed only on the same tick (e.g. because they're fed by the same clock and both repeaters have the same delay), the repeater will not switch states.

Data values[edit]

A redstone repeater is defined by its ID and block data. A redstone repeater also has a block state which is expected to replace the functionality of block data in a future version.

ID[edit]

A redstone repeater's ID specifies whether it is currently powered.

Name ID Name Block ID
Redstone Repeater (inactive) unpowered_repeater 93
Redstone Repeater (active) powered_repeater 94

A redstone repeater only exists as an item in its unpowered state (ID name: repeater; item ID: 356).

Block data[edit]

A redstone repeater's block data specifies its orientation and delay.

Bits Values
0x1
0x2
A two-bit field storing a value from 0 to 3 specifying the direction the redstone repeater is facing:
  • 0: Facing north.
  • 1: Facing east.
  • 2: Facing south.
  • 3: Facing west.
0x4
0x8
A two-bit field storing a value from 0 to 3 specifying the redstone repeater's delay:
  • 0: Delay of 1 redstone tick.
  • 1: Delay of 2 redstone tick.
  • 2: Delay of 3 redstone tick.
  • 3: Delay of 4 redstone tick.

Effectively, add the repeater's facing value (0 to 3) to 4×(delay-1). For example, a repeater facing west with a delay of 3 redstone ticks would have a block data value of 3 + 4×(3-1) = 11.

Block state[edit]

See also: Block states
Name Value Description

 delay
1 to 4 The redstone repeater's delay in redstone ticks.

 facing
north
south
east
west
The direction from the output side to the input side of a repeater.
The opposite from the direction the player faces while placing the repeater.

 locked
true
false
True if the repeater is currently locked.

Video[edit]

History[edit]

Beta
1.3 Added repeaters. Originally the four possible settings were "1, 2, 5 and 7",[1] but this was changed to "1, 2, 3, and 4".[2]
Official release
1.3.1 Redstone repeaters naturally generate inside jungle temples.
1.4.2 12w42a Added repeater locking.
1.7.2 Block IDs 93 (unlit repeater) and 94 (lit repeater) were removed from the /give command.
1.8 Repeaters no longer produce block light when powered.
Console Edition
TU1 Added redstone repeaters.

Issues[edit]

Issues relating to "Redstone Repeater" are maintained on the issue tracker. Report issues there.

References[edit]