Digital Clock Circuit Board. A wide variety of digital clock circuit board options are available to you such as ce. Select sub category frigidaire circuit board repair service.
Complete circuit diagram is enclosed herein. For this purpose this circuit make use of six 74ls90 decade counters in figure ic1 through ic6 four 74ls247 bcd to 7 segment decoders drivers ic7 through ic10 and four lt s542 common anode displays dis1 through dis4. This section is designed to display the time in hours and minutes format and is wired such that it functions in 24 hour mode.
Use pin 6 of the fifth 7490 for the american 12 hour clock.
Wire the wiper of the switch to the clock input of the fifth 7490. Use pin 7 of the fifth 7490 for the 24 hour european clock. Connect pin 6 or pin 7 of the fifth 7490 as the clocking input of the sixth 7490. Wire the wiper of the switch to the clock input of the fifth 7490.
