Ticker Tape Timer for timing motion in one dimension on a piece of paper in the form of dots spread at equal interval of time. Amplitude of vibration is adjustable. Complete assembly mounted on a metal base. Striking rate – 50 dots per second. but economical model incorporating paper tape holder. The screw shaped hammer attached to the armature moves up and down and leaves a dot on the paper strip moving carbon paper disc. An electromagnet with spring loaded armature, enclosed in metal base and operated on 12V AC.