Simple Digital Stopwatch Circuit Diagram using 555 Timer IC & CD 4033

Published September 15, 2015 58

S Saddam
Author

Often we need stopwatch to differentiate the time of two events. Here in this tutorial we are going to design a simple digital stopwatch circuit, without using any microcontroller. Here we have used the popular 555 timer IC, CD4033 ICs and few other components, which are listed below.

Required Components

IC 4033 - 2
555 timer IC -1
Common Cathode 7 Segment Display -2
150 Ohm -1
100K resistor -1
33K resistor -1
56K resistor -1
10uF capacitor -1
On/off switch -1
Push button -1
Bread board -1
9 Volt Battery -1
Battery Connector -1
LED -1
Voltage Regulator 7805 -1
Connecting wires

IC CD4033

This is counter and seven segment decoding in one package IC which is very easy to interface with seven segment displays. This is fully static counter operational IC and ideal for low power displays. This IC can be used for decade counting seven segment decimal displays, frequency division seven segment decimal displays, clocks, watches, timers, counter/display driver for meter applications.

IC 4033

Digital Stopwatch Circuit Diagram and Explanation

In this circuit we have used a 555 timer IC based astable multi-vibrator which is for creating 1 second delay. And two common cathode seven segment decoder IC’s namely CD4033. The output of astable multivibrator is directly applied to seven segment decoder IC’s (U4) Clock pin (1) and carry output pin(5) of U4 IC is directly connected to clock pin (1) of second seven segment decoder(U3). And two seven segment are connected with these decoder (U3 and U4). Its connections are shown in stopwatch circuit diagram given below. One push button is used to stop /start the stopwatch and one push button is used to reset the stopwatch. A 5 volt voltage regulator is used for providing 5 volt to whole circuit. And a 9 volt battery is used for powering the circuit. Rest of connections are shown in the circuit diagram.

Working

In this stop watch circuit we have generated one second delay by using 555 timer based astable multivibrator. By using some calculation we can easily generates one second delay. In astable multivibrator there is two resisters and one capacitor is responsible for delay by charging or discharging capacitor through resistors. Calculation formula for generating delay for astable multivibrator is given below.

F=1/T= 1.44/(R1 + 2R2) C1

In this project we have selects R1 is 33K, R2 is 56K and C1 is 10uF. [Also check: 1 minute timer circuit]

Ass Astable multi-vibrator generates one seconds delay, this delay is oscillations or pulse of 0 and 1. So we will use this pulse for triggering the seven segment decoder then seven segment decoder changes the digit number with the one second of time period.

Digital Stopwatch Block Diagram

When we ON the stopwatch (by start/stop button) it start counting from zero and if we turned OFF the same button then counting is stop or pause until again turned ON the same button or press reset button.

There are two seven segments, so this stopwatch circuit can count 00-99 seconds time.

Video

IC CD4033

555 timer IC

Stopwatch

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do you have pcb layout for

do you have pcb layout for this circuit.?

There are lot of online Tools

There are lot of online Tools and softwares available, which convert schematic into PCB layout like Fritzing, you can design a good PCB layout using those.

Component Replacements

Is there any IC available that can replace 4033 and similarly for 7805?

You can use 4026 (Check this)

You can use 4026 (Check this) in place of 4033. And you can remove 7805 and connect 9v battery directly, otherwise there are lot of voltage regulators available.

Digital StopWatch

What will be the changes in circuit connections , , if I use common anode 7 segment display instead of common cathode ?

Then you need to use Common

Then you need to use Common anode 7 segment display driver IC like IC7446, instead of 4033.

the ic4033

if i am to use the 4026 instead of 4033.. instead of connecting to rbi, i connect to DEI? thats all that changes? pliz help

yes, you can connect DE (not

yes, you can connect DE (not DEI) to Vcc like RBI, which is connected to HIGH in 4033. Leave DEO open in 4026 like RBO in 4033.

Counter

Can this circuit me modified to count manually with each push of the switch.

Yes, you can do that, just

Yes, you can do that, just connect the 555 in Monostable mode instead of Astable. Check this one: 7 segment counter circuit

Don't forget to ground the 14

Don't forget to ground the 14 pins on both the 4033s. It will work perfectly.

I've done that ..but still it

I've done that ..but still it's not working

Hi,

I am trying to extend this circuit to an activity tracker and save it to an SD card. Can this circuit be modified for that?

Hi,

Hi,
Can anyone tell me how to make the second 7 segment display count only till 5?!

thank you.

Hi.

Hi.
My output stuck at 68 its not working please help!

How can i show the hidden

How can i show the hidden pins VDD/VSS in 4033 ??

ASK

How can i show the hidden pins VDD/VSS in 4033 ?? my project error if VDD And VSS gone :D

VDD and VSS Pins are hidden

VDD and VSS Pins are hidden and by default connected to 5v power rail and Ground. Further check by Right click, Edit Properties and click on Hidden Pins of the component. This link may be helpfull: http://electronics.stackexchange.com/questions/148893/connecting-the-vdd-terminal-in-proteus

project

I want PCB layout for this ckt diagram

There are so many softwares

There are so many softwares are available for Schematic to PCB layout conversion like Easy EDA, Fritzing etc. We have made tutorial for using Easy EDA for PCB conversion Design Your Circuits Online for Free with EasyEDA

I want to be ckt diagram plz

I want to be ckt diagram plz send

is there any equivalent ic

is there any equivalent ic for ic4033

Please read all the previous

Please read all the previous comments before asking questions, we might have answered them already.

hi sir is there any

hi sir is there any suggestion of new feature to add in this circuit?

i tried with both 4033 and

i tried with both 4033 and 4026 IC's but circuit don't run

problem

which resistor you used in both common point of 7 segment cathode display . you didn,t mention that .pls help may be reason to work my circuit . otherwise everything right ..

@afrasiab @habib Try

@afrasiab @habib Try grounding the 14th pin of 4033.

Pcb design

Has anyone produced an working pcb design?

Qusetion

If i use common anode seven segment decoder here then what i have to do? please,help me

i want pcb layout for these

i want pcb layout for these circuit .CAN u tell any online tool?

I want 4033 ic in protius

I want 4033 ic in protius with pin no 8,16

I real like this site

what changes i need to do if

what changes i need to do if i use IC 4026 insteed of IC 4033 please help me

Can you upload the proteus

Can you upload the proteus project file? I am not able to unhide VSS and VDD pins i tried following the tutorial you posted earlier in comment section

The time is not changing on 7 segment

Sir, i connected tye circuit as shown in circuit but all the lcds on 7 segment glow at same time making "8" and keep on blinking.

what if I got common anode

what if I got common anode LED??
what IC should i use?? 4026 or 4033??

circuit doubt

Hello
i am having a doubt regarding the your connections....
if we connect according to the circuit diagram, what you have given in the site....
is it working????
i have connected according to it but i am unable to get the output.......
i have checked it trice....
please help me in that regard....please......

COUNTER

how can i set it at a countdown from 10-0?

Juan Karlo if you want a

Juan Karlo if you want a countdown circuit then you should create it by your self using combination of D flip flops and decoder. the flip flops will start like the circuit above from 0 to 9 i.e a counter circuit the change will you make will be in the decoder who will display 9 for 0, 8 for 1 and so on. That is it will decode in opposite manner to the circuit above.

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Simple Digital Stopwatch Circuit

Required Components

IC CD4033

Digital Stopwatch Circuit Diagram and Explanation

Working

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