Kate Playground Bullet

DESIGN

DIGITAL WATCH CLOCK: Using an astable multivibrator, we reproduce the frequency of 1Hz to be T = 1s 1 second clock. This enables each falling edge of a counter to count up.

TIME IN SECONDS:
i) Units of a second: They tell of decades 0-9. For this task we use a BCD counter (decades).
ii) Scores Second: They tell of 0-6. For this we use a counter from 0 to 6, the clock for this counter will the previous stage

TIME IN MINUTES: In the same way as these have up to 60 seconds, the timer's clock is the previous stage, the second bone.
also add a button that will make the adjustment times of minutes to put your clock an hour.


TIME IN HOURS:
i) Units of Time: This counted as follows 0,1,2,3,4,5,6,7,8,9, 0,1,2,3,4
ii) Dozens of Time: This only count of 0-2. For the hours the show in 24 hours.
iii) Also as part of minutes he set button for hours. DISPLAY


at each stage was used transcoders 7448 BCD to 7-segment common cathode.
The way of presentation is in HH MM SS (hours, minutes, seconds)

MATERIALS USED 7490 counters

6 6 7448
Transcoders common cathode displays
6 1 1 555

TTL7408 resistors and capacitors to take 1Hz clock. PHOTO

CIRCUIT Present and

was not holding my camera so the quality of this photo.