pleas help me :( -Digital Clock in Multisim


Joined Mar 14, 2008
That's a bad, non-descriptive thread title.
Please be more specific in future posts.

So what have you done so far?
This is a Homework Help forum not a Homework Do.


Joined Feb 20, 2011
-_- u wanna to help me or not
You need to help us first. We're not here to do your homework for you. You need to show us ALL of your work and attempts first. Only the will we point out where you went wrong and point you in the right direction. We will not solve anything for you.



Joined Mar 31, 2012
A schematic is definitely one step in the right direction, but it does nothing to help us understand what the problem is asking for or whether you are doing what is asked of you. Your schematic shows two four-bit circuits each driving a single digit display with no apparent interaction between them. How does this constitute a "clock"? Maybe it does, within the context of this assignment, but we have no idea what that context is. As a result, we have to guess, based on the circuit, what it is supposed to do. But if we do that then the only conclusion we can come to is that it is supposed to do whatever it is that is actually does, making it impossible to know whether there is a problem with it.

We need you to describe the specific project specifications and then walk us through YOUR design. Then we are in a position to spot areas where you are going astray.

ian field

Joined Oct 27, 2012
Repeating yourself by attaching the same file again does not move the discussion forward.
Last MSI digital clock circuit I saw used a lot of 7490 BCD decade counters and a few of the 16 bit type.

The 7490 internal structure is made up with interconnected divide 2 flip flops that reset themselves at the required count. The 16 bit counters are nothing more than cascaded divide 2 flip flops.

AFAIK: the 7490 is obsolete and had been replaced by a new device with 2 BCD counters in the same package (possibly a 74290) - the internals of either can be found online.