The stopwach was working duo to this table:Īt the beginning of our project we used 7493 BCD counter but we faced a problem that 7493 counter before it goes to the next state it go back to the initial state and start counting up to the needed state. Clear (Black) We connected all the clear together and connect it to active high pulser.

Output 'QA,QB,QC,QD' (Green) The output of the counters are connected to hexadecimal display. Clock (white) Connected with SWETCH using And Gate to deactivate it when we want to stop counting and the output of this and is connected to this clock of 1st counter. Load (Orange) We Connect it As Shown in the logic work Diagram By that way 1st Counter will count up to 9 and rest it self at the same moment it gives a clock pulse to 2nd Counter 2nd Counter Will count up to 5 then repeat it self, Once It is be came 5 & 1st Counter 9 they will give a clock pulse to the 3rd Counter which will count up to 9 and by the same way 4th counter will be pulsed. Lab Work +5 V (RED) We used it as a power supply for all IC's 0V 'ground' (Blue) We use it to set the initial value of the inputs (A,B,C,D) to be 0 To Ground All IC's. This stopwatch should have START/STOP/RESET functions and it counts up to 100 minutes (99:59) then it rests itself.Ĥ- Hexadecimal display 4- BCD counter (74-161) 1- 7408 AND Gate 1- 7400 NAND Gate 1- 7432 OR Gate Introduction: Due to importance of time in exams competition and other situations in our life, we found that stopwatch is the most useful project we may do.

StopWatch Done by Anwer Alsomaily 200841680 & Abdullah Al-Karairi 200923910 For Dr.

Project red buffer gate