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
You may also like:
can you mail me the pcb layout
can you mail the lay pcb layout
we dont get the ic mm74c926 let we know there is any replacement for it
we dont get the ic mm74c926 let we know there is any replacement for it
i would like to know how this circuit works????? anyone help me plzz
How are the resistors connected to the 7-segments ?
what is the alternative ic for 74C926?
lim did u get the alternative??
i’m done doing this stopwatch..but can’t operatingw well…the problem is cannot start….when reset,the LED show a number 8888…so what is the problem?
sir ,how we can assemble these project if we don’t know d procedure .so ,plz rply soon i wanna to module these……
how to make large size stopwatch?
sir is there any replacement for ic mm74c926?
hi can i use any other ic’s instead of mm74c926.if there any plz reply me…….
HI!!
i’m makein this ckt on EAGLE.
but m not understanding which switches to use.
plz can you help me?
hi, i am student of unikl miat located at sepang .. i learning mechanical and currently doing my fyp that need automatic digital timer or stopwatch. i really do have almost zero skill and knowledge obout this item. if u may .. could u pls elaborate this device for me . tq
ur help are highly appreciated .
HITEC UNIVERSITY STUDENT:I have Made digital stopwatch using this cct . and it is working properly.the problem is that IC2 is expensive (Rs 800) and its not available easily in market.you can use any seven segment display but it should be common cathode. its above 3rd pin should be ground.2 pole 4 position rotary switch should be used pole is connected with 22k resistor and other any two terminals with position 1 and 2.disp1 in this cct of milli sec disp2 is sec disp3 is minute.ground should be given properly use small wires as you can for breadboard.
buy from me.so how?
pls tell me the applications of the chip used.how we can expand this project?
plaese send me the required functions of the chip IC1 LM555,and IC2 MM 74C926.PLEASE INCLUDE WHY THE CAPACITANCE ARE IMPORTANT IN THIS CIRCUIT.
i have made this circuit but its not counting..its showing 0000 reading but not counting..
please help me
T1 is not listed on the parts list and T2 is there a suitable sub for this part? The 7 segment displays need pinout connections. Also part# for the 7 segment displays can’t be found is there a sub for this also. Thanks
plz snd the question for oral exam on interval measurement using 74c926
Plz snd the questions and answers of project on internal measurement using 74c926(digital stop watch)which will be asked for oral examination as early as possible.
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,
It is humbly requested that please show your any contact or email espacially email of gmail account becasue my email id is also in gmail so we can contact easily.
Email salmanwaheed2008@gmail.com
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.
i couldnt get ic 74c926.is there any alternative…
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