problem in proteus simulation

[mansman]

i simulate in proteus a digital clock project using 7490 ic , the seconds is ok but the minutes is not sixty seconds exactly it's 75 seconds i think my circuit is ok but is that error in circuit or in proteus
thanks in advance.

 

[Tahmid]

How did you deduce that seconds is okay, but minutes is not? What display are you using for showing the time?

For keeping track of time, use the simulation clock/watch/time shown at the bottom of the window to the right of the play/pause buttons. Your simulation may not be running in real-time, so a 60 seconds time simulation may be taking 75 seconds. Can you check the simulation time and tell us the time you get?

 

[mansman]

i use windows time to conclude that and i use oscilloscope on proteus to see out signals
i run simulation as always , how do i know that simulation run in real time?

 

[Tahmid]

Take a look at this image (I circled the time in red):

Hope this helps.
Tahmid.

 

[mansman]

Take a look at this image (I circled the time in red):

Hope this helps.
Tahmid.

i tried that and i find proteus delayed by appro 15 seconds

 

[Tahmid]

Can you upload the .DSN file so that I can take a look?

 

[mansman]

i simplify the circuit greatly and use clock generator and set its frequency to 1/60 to generate minute

 

[Tahmid]

It's fine.

The slight error is due to my reaction time.

 

[mansman]

this is proteus time but when i compare it to computer clock(task bar) there is slight difference in seconds about 10-15 seconds this is my point

 

[Tahmid]

You have to match it against Proteus time. You can't match it against computer time. It just won't match. Simulation doesn't occur in real time. Basically, to simulate 60 seconds, Proteus takes between 70-75 seconds.

All but the very simplest circuits will run slower than real time. So, there will always be a difference between Proteus time and computer time. For simulation, you must use Proteus time. Make it on hardware instead of simulation and you'll see that it's fine.