Abstract: A simplified, mechanical analog to digital converter mechanism useful in clocks or the like includes an impulse wheel periodically actuated by the continuous rotation of a conversion wheel coupled to a drive means such as a synchronous motor. The conversion wheel has a single tangential tang struck from its planar surface which functions on each wheel revolution to engage and advance a tooth of the impulse wheel one step. A uniform shaft rotation is thereby converted to a succession of digital steps, for example, a sweep seconds hand is converted to a jump seconds indicator.