Minecraft wiki entry for Clock, associated text: The build is somewhat tricky: The multiplier loop is in fact a torchless repeater-loop clock. This needs to be started separately, before the latches are engaged. The easiest way to start it is probably to add a temporary "startup circuit" starting 4 blocks from the dust part of the loop: Place a power source, then dust and a block for it to power. Finally place a redstone torch on the block, positioned to power the redstone loop. The torch flashes on for one tick before "realizing" it is powered, and this starts the loop as a clock, which cycles until the latches are powered. This startup rig can then be removed.