Hi arian,
This is the logic digram for 7490, why do you think it is not suitable.?

Which type of decade counter IC's do you have on your work bench.?

I would suggest you build just the Seconds , Tens and Units ,with their LED displays, drive the dividers with your 555.

This will prove the first section of the counter '00' through '59' seconds.

E

Hi! Yes I already made that, it counts until 99 tho, i don't know how to reset it an 59.
I do have 7492, 7490, 555, 7493 for counters.

 

Hello,

You will have to decode 60 from the counter and reset it to 0.
That way you will see it count until 59.

Bertus

 

i don't know how to reset it an 59.

hi,
Consider the '5' ie: 10's of Seconds
The 7490 has 4 output pins ,with the weighting [ the highest first] 8 , 4, 2, 1
On circuit digrams they are labelled as D, C, B, A

Question for you, looking at the weighting numbers which two add upto '6'.?
E

 

Hi! Yes I already made that, it counts until 99 tho, i don't know how to reset it an 59.
I do have 7492, 7490, 555, 7493 for counters.

Both the 7490 and 7492 have reset pins… Does that suggest anything?

Also, note that when wired as a decade counter, the 7490 rolls over from 9 to 0 automatically.

So how do you check that the 7492 has reached a 6? Because when it does, what do you want it to do?

 

hi,
Consider the '5' ie: 10's of Seconds
The 7490 has 4 output pins ,with the weighting [ the highest first] 8 , 4, 2, 1
On circuit digrams they are labelled as D, C, B, A

Question for you, looking at the weighting numbers which two add upto '6'.?
E

Question for you… which two powers of two add up to 6?

@bertus
Much simpler…

 

Hello,

You will have to decode 60 from the counter and reset it to 0.
That way you will see it count until 59.

Bertus

Hello!
That sounds good, but my problem is how? Right now the units of my second is counting from 0 to 9 no problem, then it will reset and tens will change to 1 but still i don't know how to decode it.

 

Hi dj,
I will post whatever I consider appropriate in answering any of the TS's questions.!
E

 

but still i don't know how to decode it.
hi arian
Read my question post #43
E

 

Both the 7490 and 7492 have reset pins… Does that suggest anything?

Also, note that when wired as a decade counter, the 7490 rolls over from 9 to 0 automatically.

So how do you check that the 7492 has reached a 6? Because when it does, what do you want it to do?

Got it for the seconds! I just need to connect Q4 from units of seconds to A clock of 7492 and then connect Q4 of the same ic to one of it's reset pins, right?

 

hi,
Consider the '5' ie: 10's of Seconds
The 7490 has 4 output pins ,with the weighting [ the highest first] 8 , 4, 2, 1
On circuit digrams they are labelled as D, C, B, A

Question for you, looking at the weighting numbers which two add upto '6'.?
E
View attachment 256236

It's QB and QC i believe or am i playing dumb?

 

hi a,
Do you have an AND gate IC on the bench.?
E

 

hi a,
Do you have an AND gate IC on the bench.?
E

Hi! Yes I do have 7408 which is AND gate!

 

hi a,
OK,
So connect the two inputs of the AND, one to 'B' and the other to 'C' , connect the AND output to the Reset pin of the 7490.

Post what you see.
E

 

hi a,
OK,
So connect the two inputs of the AND, one to 'B' and the other to 'C' , connect the AND output to the Reset pin of the 7490.

Post what you see.
E

We're talking about the units and tens of seconds? Or the connection between tens of seconds to units of minutes? And is there a difference between which reset pin i connect the AND output?

 

hi a,
I will post a diagram for the Seconds counter.
E
The RED pin labels show where the wires should be connected.
eg: 'd' to 'd' etc.. do you follow that OK.?

 

hi a,
I will post a diagram for the Seconds counter.
E
The RED pin labels show where the wires should be connected.
eg: 'd' to 'd' etc.. do you follow that OK.?

View attachment 256239View attachment 256240

Hi!
Thank you so much! It's working! Counts from 0 to 59 then return to 0!
Now i should connect it to the units of minutes, right?

 

hi a,
Well done.
So xx:xx:59 is done
The Cy1 is the One Minute input clock.

Use that to clock the Units of Minutes counter, check that out, then add the Tens of minutes counter, that will be the same circuit as the Seconds pair of counters.
xx:59:59

E

 

hi a,
Well done.
So xx:xx:59 is done
The Cy1 is the One Minute input clock.

Use that to clock the Units of Minutes counter, check that out, then add the Tens of minutes counter, that will be the same circuit as the Seconds pair of counters.
xx:59:59

E

Did it! On paper of course! Can i do it in proteus too just to be sure?
And now how should i do the hour? For the unit i'm using 7490 and for the tens i'm using 7492.
And it will be a 24 hour clock... which means it goes up to 23:59:59 then reset to 0.

 

hi,
Try it in proteus , post your circuit.

Note: at the change 23:59:59 >>> 24:00:00 you must reset all the Counters.
Also, for a good design should set all the Counters at 00:00:00 at power ON.

Have you considered how you are going SET the clock to the Real time.???

E

 

hi,
Try it in proteus , post your circuit.

Note: at the change 23:59:59 >>> 24:00:00 you must reset all the Counters.
Also, for a good design should set all the Counters at 00:00:00 at power ON.

Have you considered how you are going SET the clock to the Real time.???

E

No i really haven't considered that... also how should i reset all the counter on 23:59:59? Like with a gate or something so the circuit can do it automatically?