Scoreboard Counter 0-100 with 10 minutes countdown using only logic gates. And 555 timer

 

hi ganny,
Look at the 74LS192 for up/down BCD and 74LS247 for 7 Segment drivers.
As your query is a homework assignment, we would expect you to post your effort in creating the circuit.
Eric

 

By the way it should increment 1 , 2 and 3 and decrement of 1. I did is just increment of 1 I dont what to do next

 

hi g,
In your opening post you said count down,????
Do you mean an Up counter from 000 to 100 in one count increments.?

When using CMOS IC's it is important not leave any INPUT pins disconnected 'floating'.
A CD4026 will only count up.
E
Cleaned up your image..

 

Sorry, it should increment 1,2,3 from 000-100 for example from 000 I push the button for increment of 2 the output will 002 when I push the button for increment 3 the output will be 005. Thats what my problem is

 

hi,
Are you using a simulation circuit or an actual built circuit.

E

 

An actual built circuit and it should be discreet

 

OK,
I would recommend that you initially limit the circuit to one CD4026 IC, until you get that one counting from 0 to 9.

If you are using a mechanical switch for the Clock source, it requires 'debouncing', that means as the switch is closed the contacts may bounce and cause multiple clock pulses.
Do you have a Schmitt logic gate available to make a debounce circuit?
A CD40106 , CD4093, ?
E

 

Do you mean momentary switch? Yes I will use it. For the meantime my problem is I downt how to make it incrment by 2 and 3 and decrement by 1

 

my problem is I downt how to make it incrment by 2 and 3 and decrement by 1

Sorry, I do not follow what you are asking.?
Do you mean increment by one each switch push
0 1 2 3 4 5 6 7 8 9

You cannot decrement using a CD4026
E

 

Ahhh. What should ic should I use?

 

Look at my post #2.