Redstone Logic Masterclass: Pulse Extenders, Clocks & Comparators

Redstone is Minecraft's built-in electrical engineering system. Whether you are building an automated farm, a hidden piston door, or a complex minigame, mastering Redstone Comparators and timing delays is essential.

Redstone Comparator: Comparison vs. Subtraction Mode

The Redstone Comparator has two modes toggled by right-clicking it:

Comparison Mode (Front Light OFF)

Compares the Signal Strength of the back input (A) against the side input (B). If Signal A is greater than or equal to Signal B, Signal A passes through unchanged. If Signal B is stronger, the comparator outputs 0.

Subtraction Mode (Front Light ON)

Subtracts the side Signal B strength from the back Signal A strength (Output = A - B). This mode is used in rapid pulse clocks, item sorters, and analog memory circuits.

Building Reliable Pulse Extenders

Standard buttons only send a short signal (10 to 15 redstone ticks). To keep a piston door open longer, connect two comparators facing opposite directions in a loop with redstone dust. This creates a decaying container signal that slowly drains, keeping the output active for 3 to 10 seconds.

Calculate precise tick delays for your contraptions using our Redstone Delay Calculator!