Minecraft wiki entry for Clock, associated text: With the repeater set to a 1-tick delay, this is a 2-clock (2 ticks on, 2 ticks off). Increase the repeater delay to slow the clock down, or even add additional repeaters. If the input strength is higher than 1, the block behind the repeater can be replaced with redstone dust; if higher than 2, the block in front of the comparator can also be replaced with redstone dust. Output can be taken from anywhere as long as the dot of redstone dust can power the block behind the repeater.