STOP WATCH

4TP09

2B-STOP WATCH

PROJECT SPECIALITIES

The electronics has entered each and every sphere of our activities including that of sports. This project can be used as a Stop Watch in games / sports and fun games etc. The time taken by any player can be measured with the help of this stop watch. As such this project is a gift to the field of sports.

TECHNICAL DESCRIPTION AND WORKING

 

This project has been developed and tested O.K. in our TV Engineers Technical Lab.  The components and PCB used in the projects published in our books are available for sale at resonable price.

This project can even count 1/10th of a sec. and counting stops on that position when the stop – switch is pushed. When the reset button is pushed, the counting starts again from zero. This project employes  ICs 555(two nos) , IC 4033 (three nos) and common cathode FND. The IC 4033 is a seven segment de-corder or de-cade counter IC. When the start button connected to pin no 2 of 1st IC 555 is pressed, the clock pulse start generating from its output. The output is applied to reset pin no. 4 of second IC 555 and as a result the information at pin no. 4 becomes high.  The clock pulse of 1/10 th sec. is generated at the output of second IC 555 which is applied to the pin no 1 of counter IC 4033.  The counting 1st, 2nd and 3rd IC 4033 starts at the ratio of 1/10th part of a sec. , 1sec. and 10 sec. The counting stops on that point as soon as STOP button is pressed. It starts counting again once the reset button is pressed.

PRECAUTIONS WHILE ASSEMBLING THE PROJECT:-

*Use IC base for mounting of the ICs otherwise IC may damage due to current leakage of soldering iron.

*First of all check all the components as per circuit.

*Please use resistance of the exact value as given in the circuit.

*Check Dry SOLDERING and short circuit in the board after SOLDERING.

*For better result you have to operate this project first of all at 9V DC supply.

*Check +ve & -ve terminal of L.E.D. while mounting on PCB.

 

PART LIST

IC4033 = 3

IC 555 = 2

FND [COMMON CATHODE] = 1

PUSH TO ON SWITCH = 3

CAPACITOR

1MFD/25V = 1

RESISTANCE

10K = 3

4.7K = 1

150E = 21

100E = 1

PRESET

100K = 1

L.E.D = 1