Method of operation right|thumb|Schematic of a split-flap display in a digital clock display An electric motor (often synchronous, if directly connected to the AC line) turns two sets of wheels continuously via a reduction gear train: the faster at a rate of 1 revolution per hour, the slower at a rate of 1 revolution per 24 hours. The wheels move continuously, not in steps.
Method of operation right|thumb|Schematic of a split-flap display in a digital clock display An electric motor (often synchronous if directly connected to the AC line) turns two sets of wheels continuously via a reduction gear train the faster at a rate of 1 revolution per hour, the slower at a rate of 1 revolution per 24 hours The wheels move continuously, not in steps.