Need help in constuction of basic queuing system

[whompah]

Construct a basic queuing system that is used in banks, counters. Given a situation that Mr.A in room 1 and Mr.B in room 2, both of them have a push button which gives +1 logic when pushed and 0 when released. Here is the conditions needed to be fulfilled:
1) If. Mr. A pushes the button, 1 will be displayed in the LED 7-segment display
2) if Mr. B pushes the button, 2 will be displayed in the LED 7-segment display
3) If they press the buttons together at the same time, Mr.A takes priority and 1 will be displayed.

1 and 2 i definitely know, but i don't know how to implement condition 3 although it sounds very very simple. Hope seniors here can enlighten me. Thank you

 

[ericgibbs]

Construct a basic queuing system that is used in banks, counters. Given a situation that Mr.A in room 1 and Mr.B in room 2, both of them have a push button which gives +1 logic when pushed and 0 when released. Here is the conditions needed to be fulfilled:
1) If. Mr. A pushes the button, 1 will be displayed in the LED 7-segment display
2) if Mr. B pushes the button, 2 will be displayed in the LED 7-segment display
3) If they press the buttons together at the same time, Mr.A takes priority and 1 will be displayed.

1 and 2 i definitely know, but i don't know how to implement condition 3 although it sounds very very simple. Hope seniors here can enlighten me. Thank you

hi and welcome,

If you post what you have done for #1 and #2, we could give you some ideas about #3.

 

[whompah]

View attachment 63213
attached screenshot is here, if condition 3 is to be taken into account, then i think the entire system has to be modified, but the attached screenshot is my basic idea.
Thanks for replying

 

[ericgibbs]

View attachment 63213
attached screenshot is here, if condition 3 is to be taken into account, then i think the entire system has to be modified, but the attached screenshot is my basic idea.
Thanks for replying

Hi,
IF the push switches are really changeover, you could try this.

 

[whompah]

View attachment 63238
View attachment 63239
thanks for the help. but so far I constructed 2 different designs with same circuit parameters (Vcc=5V and all resistors value=250ohm) and i found out something. Check out the 2 attached pictures.
why is the leakage current different ?
and what is the effect of current flowing back to the output of IC logic gates ?