I made a 12 hour clock. Here is a link to the schematic. I left out the seconds section. The minutes works fine. The hours
resets at 5 hours. I verified that the wiring is correct. Not sure if the schematic for hours section is correct. Please advise.

 

It looks to me as though it should reset when b and c are lit on the tens of hours, and c, f and g are lit on the hours, which would happen when it gets to 14.
Shouldn't it reset when b and c are lit on the tens of hours and when any of a, d or g are lit on the hours?
But that wouldn't explain why it resets at 5. Does the tens of hours digit work?

 

It looks to me as though it should reset when b and c are lit on the tens of hours, and c, f and g are lit on the hours, which would happen when it gets to 14.
Shouldn't it reset when b and c are lit on the tens of hours and when any of a, d or g are lit on the hours?
But that wouldn't explain why it resets at 5. Does the tens of hours digit work?

The tens of hours digit displays a zero but the count never gets high enough to display anything else.

I agree with the reset b and C and a,d ang g. Should that 0.01uF capacitor be connected to D2? It would
block the signal to pin 6 of IC6 wouldn't it?

 

The tens of hours digit displays a zero but the count never gets high enough to display anything else.

That's part of the problem, because it should have the ripple blanking enabled from the RBI input. Otherwise, detecting b and c segments being lit gives the same answer for 1 as it does for 0.
I'm not sure what the connection to the INH pin is for.

 

ya

That's part of the problem, because it should have the ripple blanking enabled from the RBI input. Otherwise, detecting b and c segments being lit gives the same answer for 1 as it does for 0.
I'm not sure what the connection to the INH pin is for.
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That INH connection has me baffled too.

 

Certainly the explanations are reasonable, but the solution would be to do a complete decode WITH AN ADDITION of another bit that is set only when both hour digits are "1" That would be a simple. That extra bit would be reset along with the other bits that get reset when the count rolls to 12.