Minecraft wiki entry for Clock, associated text: The latches are driven by an edge detector, which takes a rising edge and produces an OFF pulse; the pulse length must match the delays of the latched repeaters, so that the multiplier's pulse advances one repeater per edge. The delay/pulse length must also be no longer than the input clock, so it's probably best to keep them both at 1. Note that the delays of the latched repeaters are not actually part of the output period; the latches count off input edges. The circuit's output is ON while the last repeater is lit and lighting the dust loop.