COUNTER CIRCUIT WITH 12 HOUR DISPLAY*24 HOUR DISPLAY CHANGEOVER FUNCTION

摘要

PURPOSE:To achieve the simplification of circuit constitution by making use of a ring type counter. CONSTITUTION:The counter circuit is constituted by a decimal counter crcuit 1 and binary counter circuits 2, 3 so that the hour pulses outputted from an ''hour'' pulse generating circuit 6 are counted. Then, when 12-hour display is performed by changing over a scale-of-12/24 control circuit 4 by the signal from a 12-hour display/24-hour display selection circuit 7, the duodecimal counter circuit which indicates the order of ''1'' with the decimal counter circuit 1 and the order of ''10'' with the binary counter circuit 2 is constituted and ''AN/PM'' is indicated by the binary counter circuit 3. If 24-hour display is selected, the decimal counter circuit 1 operates as a decimal counter circuit indicating the lower digits of the ''hour'' and the binary counter circuits 2, 3 operate as a counter circuit indicating the upper digits.