LTspice 4 Trouble With Transient Simulation Reults

[Pisancho]

Hi guys i'm a newbie here. I am trying to simulate a circuit to determine whether the theoretical time response is the same as that which is simulated from a graph and i believe it should but i get a very large difference in the theoretical and simulated result. I'm also not sure if my graph is correct as its my first time using this software. I have uploaded the circuit to be simulated and my graph which i really believe to be wrong. Any help would greatly be appreciated. Thank you.

 

[Pisancho]

Rs is 100 ohm, R is 820 ohm, The pulse is from 0 to 5 volts and the capacitor is 150nF

 

[Alec_t]

Post your asc file, so that we can see the voltage source parameters and where you're 'Vout' point is.

 

[Pisancho]

here you go

 

[Pisancho]

Post your asc file, so that we can see the voltage source parameters and where you're 'Vout' point is.

I have sent it. It is telling me awaiting moderator approval which is weird haha

 

[LvW]

Doing a TRAN analysis the most important parameter is the specufied (minimum) time step (time resolution).
I always would suggest to use AT LEAST 1000 points within the simulation time.
So - for a simulation time of 1 sec I recommend a minimum step of 1msec.
What was your choice?

 

[Pisancho]

Doing a TRAN analysis the most important parameter is the specufied (minimum) time step (time resolution).
I always would suggest to use AT LEAST 1000 points within the simulation time.
So - for a simulation time of 1 sec I recommend a minimum step of 1msec.
What was your choice?

Thank you for reply. I am new to this simulator and i followed an example tutorial on how to do it. Where do i find the time resolution?

 

[Pisancho]

Thank you for reply. I am new to this simulator and i followed an example tutorial on how to do it. Where do i find the time resolution?

I set T delay to 0, T rise to zero, T fall to zero, T on for 1 second, The period to 2 seconds and the number of cycles to one. Those were the only parameters he said to change.

 

[Pisancho]

I set T delay to 0, T rise to zero, T fall to zero, T on for 1 second, The period to 2 seconds and the number of cycles to one. Those were the only parameters he said to change.

And stop time to 2 seconds in the simulation

 

[Alec_t]

LTspice doesn't accept zero for the rise or fall time and will substitute its own times (0.1 sec in your case, which is what your graph shows). Replace zero with a practical value, e.g. 1u.