up/ down counter using 555, 4510, 4511 and 7 segment display

[pro]

i ve got a small problem in that im struggling to get a circuit that counts up and down using a 555, 4510, and 4511 with a seven segment display to work. does annyone have a clear circuit diagram that could help. if so id be much appreciated, cheers matt

 

[Russlk]

Well, need some more info: How fast is the count? You have to stop the count sometime, or there will not be a readable output, so what is that criteria? How many digits?

 

[pro]

basically the idea of the circuit that i have to make is a clock in and out for a bouncer. so basically a push button needs to be pushed to clock a person and the counter needs to go up, and when a person comes out they have to be clocked out, ie the counter needs to count down. its basically for fire safety. i have decided to use 3 seven segemenen displays, ie so that the counter can go up to 999.

 

[ljcox]

We could help you better if you post a copy of your circuit. You may be having problems with contact bounce. Switch contacts bounce (ie. open and close several times rapidly when operated). So your counter will count these hence incrementing more than once per button push.

There was a post re contact bounce some weeks ago. I made a contribution, so if you look at my profile and search my posts, you should find it.

Len

 

[Russlk]

I don't know why you have the 555 timer, check out this circuit. I think it works, if you build it and have problems, let me know.

 

[hutas832]

i got it to count up... but how can i make it count up n down as the frequency changes... ????

 

[Reloadron]

Can you post your circuit? This thread began in 2004 with a single post in 2008 so it is an old thread. For any help you will need to post your circuit schematic.

Ron

 

[crutschow]

You might use a CD40110 Up/Down counter. It directly drives a 7-segment display so you need just one chip per digit.

You will, of course, need a contact debounce circuit to drive the Up/Down inputs as mentioned. A Google of "debounce circuits" will turn up many.

 

[crutschow]

Will the two that have hijacked this thread with there own questions please start a new thread.