This is a simple up and down circuit that can be implemented in various digital circuit applications. I know this is useful to students in their projects and thesis design.
I use a 74ls190 (SYNCHRONOUS UP/DOWN COUNTERS WITH DOWN/UP MODE CONTROL) for this circuit. You can check it’s datasheet to know its capabilities.
Here is the circuit (click here):
Here’s the video of the circuit in a breadboard:
with a clock:
There are lots of ICs you can use as a counter. And also, you can improve this circuit depending on your needs.
Never stop learning. . .
Tags: 74ls190, 7segment display, bcd, counter, digital electronics, up/down counter
Rowatronix 
December 22, 2009 at 5:41 pm |
If I want to use 3 7-segment what is the circuit or connection now?… can you teach me?. thank you!
December 22, 2009 at 11:03 pm |
you just need to add.. 1-74190, 1-7447 and 1-seven segment display..
in connections, just connect the pin 13 of the second 74190 to pin 13 of the third 74190.. then, every connection is the same to the second 74190..
January 20, 2010 at 12:45 am |
hey thr, im gnimrezt,
the guy from the youtube that sent u mail asking for help.
I’ve constucted my own circuit using 74192.
But the confusing part is, where should i place my clock using function generator ( to supply frequency )??
January 31, 2010 at 9:03 pm |
i just want you to know that i am using a 74190 up/down counter IC. you asked for 74192 which is also a up/down counter.
well, i can help you with that. i checked the datasheet of 74192 and it seems that it doesnt contain a pin for clock input. it has a down count pin and a up count pin which are pin4 and pin 5 respectively. i am wondering on what application you’ll use it. if you need an increment counting, put the clock source coming from your frequency generator to pin 5. otherwise, if its for decrement counting, put to pin 4.
if you have further question, just post a reply. also, please indicate for what application is the project.
October 20, 2010 at 5:57 pm
HI! gud eve!
i just wwanna u\ask how am i going to connect if i am going to use 192 in an up/down counter application… tnks much!
October 26, 2010 at 1:40 am
first, please read the datasheet..
then, try to understand this schematic..
January 31, 2010 at 12:30 am |
Is the 7-segment display a Cathode or Anode type?
January 31, 2010 at 9:06 pm |
it is a common anode type since we are using a 7447 bcd decoder.. if you will use a 7448 decoder, you will need a common cathode type.
February 3, 2010 at 6:02 am |
Do you know where I can get an off the shelf power supply for this type of up/down counter?
February 3, 2010 at 3:29 pm |
what do you mean ba shelf power supply?
February 3, 2010 at 9:33 pm |
one you can purchase from a store or online without building it from scratch.
February 4, 2010 at 8:46 pm |
i can suggest few websites that sell this kind of counter.
http://www.electronickits.com/kit/complete/elec/ck1612.htm
http://www.hobbyengineering.com/H1253.html
http://www.rapidonline.com/sku/Educational-Products/Projects-Robotics/Electronic-Projects/Multifunction-up-down-counter-kit/78036/48-0756
please take note that these electronics kits use different components. if you want my design, i will be able to build one for you.
February 19, 2010 at 10:47 am |
Hi rowatronix,
I am unable to get the circuit to work properly. How exactly do you wire up the 7 segment display, the current limiting resistor to the 7 segment display, and power to the 7 segment display? Also, can I use a 74ls191 counter with the 74ls47 decoder? If you have an opportunity to provide the full wiring diagram that would be great. Thank you again.
February 20, 2010 at 6:51 pm |
thank you very much for sharing your expertise…:)
March 1, 2010 at 1:29 pm |
i followed the circuit above but my circuit randomly count up or down,, or sometimes it skips numbers.. how can i resolve this..
March 9, 2010 at 2:10 am |
1. randomly counts up or down? please double check all the connection.. the circuit must work properly..
2. when it comes to skipping of numbers/count.. this might cause bouncing.. please search about switch bounce and look for switch debouncer circuit to solve the problem..
March 3, 2010 at 1:30 pm |
cn u help me!i need circuit of 2 digit up down counter that has separate switch to count
March 9, 2010 at 2:18 am |
what do you mean with separate switch? the switch of up and down?
you need to work on a different chip.. you will use 74192 for that..
March 29, 2010 at 9:57 pm |
im a beginner and im trying to make an up down counter that counts down drom 26 to 0 and when its at 26 to 0 a green led must light up and when the counter reaches 0 a red led must light up. i have managed to set it to start at 26 but how do i manage to make the leds light up and that the count doesnt go beyond 0 and 26. any help will be appreciated.
March 31, 2010 at 10:00 pm |
you need to use NOR gate and AND gate combinational circuit on the output of 74190. both for 26 and 0.
then use a tri-state buffer 74126 to cut the clock source.
May 3, 2010 at 4:53 am |
Hi, i have a problem i made the circuit above but instead of putting a switch i put a LM555 as astable but my 74ls190 doesn’t count and i don’t know if is something that i missed from the schematic or is my 74ls190 that is damaged
May 3, 2010 at 11:40 am |
Hmm.. You can do these:
1. Check if your 555 astable works properly by testing it using an LED.
2. If the pull-up resistor(R1 = 1k) in my schematic is still included in your circuit, try to remove it and put the pin 3 of your 555 directly to the pin14 (clock) of the 1st 74190. Make sure that you use 5volts supply.
3. Test first your 47190 using a switch. If it does work, then your 74190 is not yet damage. In case that it doesn’t work, by an extra 74190 and test it first using a switch then if it works, connect it to your 555.
May 16, 2010 at 9:06 pm |
hey there,
im pondering on how to have a loadable up down counter, because i want to be able to set a value and then go on counting up or down as i desire, any thoughts sir?
September 18, 2010 at 9:29 pm |
Good day sir,
i’m having a problem with cascading counter (counting from 00 to 99) using a 74192 ic…it does’t count…i can’t find the problem…
October 26, 2010 at 1:26 am |
please show your schematic. let me see if i can help you.
September 25, 2010 at 10:05 pm |
hi!! do you have the schematic diagram for the second video?! how do i connect the clock in the diagram.. and i need a circuit with logic gates,, would you mind if you send me a copy..
September 27, 2010 at 6:22 pm |
Hi!! I would like to construct the circuit of the second video,, do you have the complete schematic diagram?! we need it for our project.. Thank you!! 😀
October 26, 2010 at 1:29 am |
hi gjce,
for you to build the circuit like the 2nd video, you just need to add a 555 timer(in astable operation) on the clk pin of the 74190. so basically, you will replace the (SW1)switch1 with output of the 555 timer IC.
October 13, 2010 at 12:13 pm |
Ok, I’m able to make the clock count up to 60 and reset to 0 and start counting again but now I need it to hold at 0 until a seperate signal causes it to start again. Any suggestions?
October 26, 2010 at 1:33 am |
you can use a 4-input NOR gate connected to a switch(3state buffer, relay, transistor, etc) that disconnects the link between your pulse source to the clock pin.
October 15, 2010 at 1:06 am |
what kind of switch do you use to count up or down? can i have the schematic? in our plate we are allowed to use DIP switch to control up/down count.. plzzz. thank you….
October 26, 2010 at 1:34 am |
i am using a simple push button. though any kind of switch is possible as long as you change the logic state to the clk pin of 74190.
October 17, 2010 at 12:47 pm |
hello,
just wanna ask: is it possible for me to design a circuit that will count down by 60mins/secs? i mean, for example, the time will start at 59:59, then when it reaches 59:00 it should show 58:59, and so forth, till it time is up?
thanks in advance.
October 26, 2010 at 1:37 am |
asking me if it’s possible, of course it is.
but i never think of doing that since that requires a little more time.
i would rather build that using a microcontroller.
October 28, 2010 at 10:22 pm |
Sir, would you please tell me the ff.
*pin connections
*basic operation
*the logic gates
*diagrams
*truth table
thank you sir,
xD
November 14, 2010 at 9:34 am |
Hi, how can is “freeze” the display, when it counts to 9? I am using a 74LS191 IC. My timer circuit already is working, i just wan to stop it when it reach 9 coz it will repeat counting from 0-9. Pls give some advice sir, thx.
November 27, 2010 at 1:28 am |
try to use some logic gates combination connected to the output of your counter.