4_h_DIGITAL_WATCH

Published:2009/7/1 3:22:00 Author:May | From:SeekIC

Single Motorola MC14521 CMOS IC drives single-digit MAN 3 LED display in such a way that time range of 4 h is obtained wIth 1.875 min resolution. Can be built into old watch case at cost under $10 for parts.Oscillator frequency of 1.165 kHz can be tweaked to ad just dock, or crystal oscillator can be added for high accuracy. Analog/binary format of readout provides deciphering challenge to user, even though article gives diagram showing which segments of LED are lit for each time reading. Time intenrals represented by each lit segment of display are: B = 2 h; C = 1 h; A = 30 min; F = 15 min; G = 7.5 min; E = 3.75 min; D = 1.875 min.-R. M. Steimle, Small CMOS Digital Watch Has Analog LED Output, EDN Magazine, Aug. 20, 1976, p 86.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Measuring_and_Test_Circuit/4_h_DIGITAL_WATCH.html

Print this Page | Comments | Reading(3)