What Are Redstone Clocks

A redstone clock is a circuit that produces a cyclic signal — on, off, on again, infinitely looping. Clocks are core to automation: timing pistons, droppers, dispensers. A pulse generator produces a one-shot short pulse, often for button/pressure plate triggers that run machines briefly.

Three Common Clocks

1) Redstone torch clock — simplest, 2 torches + redstone cross-connected, auto-loops. Fast (~0.2s/cycle), good for rapid pulses. 2) Comparator clock — comparator in subtract mode with redstone line, adjustable speed. 3) Hopper clock — two hoppers passing items + comparator detection, longest period (seconds to minutes), ideal for long timers.

Three clocks, three different jobs Redstone Clocks: Pick by Speed, Not by Habit Period is measured in ticks — 1 redstone tick = 2 game ticks = 0.1 s. A · Repeater loop — simple and adjustable 2 2 Period = 2 × delay × count 2 repeaters at 2 ticks = 8 ticks = 0.4 s Needs a lever pulse to start. B · Comparator pulse — fast, compact C Period ≈ 2 ticks (0.1 s) Fastest common clock; great for zero-tick farms and fast pistons. C · Hopper clock — slow and precise H H C Period = items × 8 ticks e.g. 20 items → 160 ticks = 8 s Best for minutes-long cycles that repeaters cannot reach.
A repeater loop is the workhorse: its period is simply twice the delay times the number of repeaters, so you tune it by clicking the repeaters. A comparator pulse clock runs at about one tenth of a second and is what you want for fast piston work. A hopper clock trades speed for range — each item in the loop adds eight ticks, so twenty items give a clean eight-second cycle that no reasonable repeater chain could produce.
Tip: Hopper clocks are timer masters: item count sets the period. 1 item ≈ 0.4s, 64 items ≈ 25s. Control trigger frequency by item count.

Pulse Generators

Pulse generators convert sustained signals into brief pulses. Classic design: sticky piston + redstone block — on button press, piston extends the block 1 tick then retracts, creating an ultra-short pulse. Uses: fire droppers once (not continuously), trigger TNT, activate brief mechanisms. Pair with observers to detect block changes and emit pulses.

Related guides： Redstone Basics · Redstone Hidden Door Guide · Cobblestone Generator Guide
✓ Last verified on Minecraft 1.22 (2026-09-22) Minecraft mechanics change with every update — this guide is only guaranteed to work in the stated version.