Please: I need help for a design digital counter for possesion ball in basketball

Hello friends,

The question is realizing a clock that imitates the functioning of the possession time ball of an equipment of basketball (24 seconds) using as principal module the integrated counter 74192. The circuit will have the following elements:
4 push-buttons:
One to load 24 seconds.
One for start / end.
Other one for manual advance of the seconds (one for every pulsation)
And to finish one for manual setback of the seconds (one for every pulsation).

These last two push-buttons will be in use for fitting manually the seconds that are absent (when there are discrepancies between umpire and the table for example) and only they were acting when the account is stopped.
Finally, in output we will have two Displays (already decoded component Hex Digit Display) to visualize the time and a LED that will be illuminated when the descending account comes to 00, in whose moment will stop automatically the account.

Best regards.

Have you done a search for "counters"?

There have been plenty of posts with regard to counters in the last few years.

I have done some myself.

Also search for "contact bounce.