Digital Stop Watch
Make a Digital Stop Watch
Description
A digital stop watch built around timer IC LM555 and 4-digit counter IC MM74C926 with multiplexed 7-segment LED display. MM74C926 consists of a 4-digit counter, an internal output latch, npn output sourcing drivers for common cathode, 7-segment display and an internal multiplexing circuitry with four multiplexing outputs. The counter advances on negative edge of the clock. The clock is generated by timer IC LM555. The circuit works off a 5V power supply. It can be easily assembled on a general-purpose PCB. Enclose the circuit in a metal box with provisions for four 7-segment displays, rotary switch S1, start/stop switch S2 and reset switch S3
Testing
First, reset the circuit by pressing S3 so that the display shows ‘0000.’ Now open switch S2 for the stop watch to start counting the time. If you want to stop the clock, close S2. Rotary switch S1 is used to select the different time periods at the output of the astable multivibrator (IC1).
Digital Timer Circuit Diagram .
Digital Timer Circuit
You may also be interested in other Timer circuits we have in our website:
1. Long Duration Timer Circuit
For more circuits, please check our category on Clocking and Timer Circuits
Hi Naish use the following data for your connections
http://www.datasheetcatalog.org/datasheet/hp/HDSP-5507.pdf
i m not finding hw to cofigurate resistor with sevensegment…plz help me..
okey..thank you very for responding..!!..
Hi Asichi MM74C926 is an LSI with lots of digital circuits integrated into it. with discrete 741s you cannot build up the required circuit.
instead of using 74c926… can i use 74ls series of ic.??
if yes,.what type of 74ls can i use.?
Dear Friends,
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thanks.
i have made this circuit but its not counting..its showing 0000 reading but not counting..plus the 555timer is not working with LED but its absolutely okay
plz help
i want pcb design of digital stopwatch.please send me.
I cant find mm74c926 in multisim too. what can i use instead of it ??
Thanks
sir, plz send me more details of itz component and a fine circuit plzz i will be vry thankful to u sir….
Please send me the pcb layout. tnx
i wanted the digital stop watch uing bcd’s and simple circuits
i have to make it on multisim but i cant find mm74c926 in multi. what can i use instead of it ??
oh man… this circuit saved me from my subject,it really worked, and it impressed my instructor..
it has two functions… the regular stopwatch and the split type.
though the ic 74c926 type is expensive.
i have pics on my facebook account of this project.
piease send the good circuits to my email id
RESET PROBLEM: why won’t it reset when the timer is on stop mode?
sir, i tried this circuit of yours digital stop watch, and it works fine….thing is the hundredth of a second works, but when it comes in the minute counting, it doesn’t stop at 60 but goes to 99…what to do…please help…thanks
I want to khnow scope of digital stopwatch.
i want detail info about project. pls help
how can digital stop watch works it is a MM74C926 decade coUnter IC how it could count i me to say a digital stop watch will count 60sec and then reset.
since a 74C926 counter is not there when simulating the circuit for the stopwatch, can a up/ down counter be used instead of this one? or which counter can be used?
please send me the pcb of led drivers