I'm getting different results with the LTspice simulation

Thread Starter

the machinist

Joined Apr 1, 2021
17
1618984196632.pngthe answer from the bookthe answer from the bookthe answer from the book
Hi,
There was an example from my book and I wanted to build the same circuit on LTspice to test the results.
However, when I create to simulate the circuit in the LTSpice environment you see below with the different outcome values.
1618984236004.png
and here my ltspice results:
1618984397408.png
I could not find the same voltage and current values with the currently shown hand-draw results.
What is the mistake I do please?
 

Attachments

Thread Starter

the machinist

Joined Apr 1, 2021
17
hi tm,
Welcome to AAC,
Please post your LTS asc file and we can compare results.
E
Ah yeah sure, thank you:

I made 2 different run forms. One of it was run by 1 {freq} {freq} and other asc. file has been run by 2 {freq} {freq+1n} with 2 point "sweep"
edit: The reason why I used 2 sweep points, just because of testing the component voltages and currents one by one.
and other asc. file which I posted was created with a single-point run AC view.
 

Attachments

ericgibbs

Joined Jan 29, 2010
13,652
Hi,
I am unable to run the sim due to you having used models for your inductors.
Do you know the LTSpice equivalent inductance values, I can then use the LTS version.
R
 

Thread Starter

the machinist

Joined Apr 1, 2021
17
Hi,
I am unable to run the sim due to you having used models for your inductors.
Do you know the LTSpice equivalent inductance values, I can then use the LTS version.
R
Yeah, sorry I added some external library files.
Let me re-generate it with the general components.

edit: I re-drawed them, please you can check them again.
 

Attachments

Last edited:

LvW

Joined Jun 13, 2013
1,300
I could not find the same voltage and current values with the currently shown hand-draw results.
What is the mistake I do please?
Are you sure that your program can read the shown values for the inductances L1-L3?
I rather think you must specify the inductance in H(enry).
 

Thread Starter

the machinist

Joined Apr 1, 2021
17
Are you sure that your program can read the value for the inductances L1-L3?
I rather think you must specify the inductance in H(enry).
Actually, I just followed this example below to use ".param" code with that inductance form:
1618995181301.png

So, the variables which were given in the examples such as "j0.5, j1.5 and j28" could be written in this form with LTspice?
and also here is the link that I followed to create this circuit:
https://electronics.stackexchange.c...uld-i-simulate-a-circuit-like-this-in-ltspice
 

LvW

Joined Jun 13, 2013
1,300
Actually, I just followed this example below to use ".param" code with that inductance form:
View attachment 236118

So, the variables which were given in the examples such as "j0.5, j1.5 and j28" could be written in this form with LTspice?
and also here is the link that I followed to create this circuit:
https://electronics.stackexchange.c...uld-i-simulate-a-circuit-like-this-in-ltspice
OK, if it works - fine. I was not sure about it. Therefore my comment.
 

Thread Starter

the machinist

Joined Apr 1, 2021
17
hi,
This what LTS reports on your 2nd circuit.
E
A clip of yours & mine
Note R1 & R2 difference

View attachment 236139
It seems that we have encountered the same outputs.
However, here in example 11.1 of the book which is "Electric Cİrcuits James W. Nilsson 10th Edition - page 425" says:
1619006121160.png 1619006029056.png

Unfortunately, when I compare my own asc results with this example answer that was already solved in the book is completely different.

Thus, I just got the problem with solving hand-drawn. I only stuck by testing it with the simulation.
I just thought that I could find the same results with that theoretical way...
 

Thread Starter

the machinist

Joined Apr 1, 2021
17
hi,
Did you try a LTS sim with the actual Inductive values.?
This is what I get.

Could you post your hand-calculated results?
E
Yeah, let me try it with the inductive values.
My hand calculations were the same as the given answers column of the example. (I just learned how to solve it from the book yet. Due to the online lecture education, our teacher just gives us a duty to work alone. that is why this term is so harsh to get them with studying them from this book. To me, the calculation is not that much clear but I just really don't know that if that answer enough to get things clear)
 

Thread Starter

the machinist

Joined Apr 1, 2021
17
I still could not figure out that the reason why I couldn't find out the same current and voltages with my ltspice asc. Anyways I'm really sorry to ask.
 

Thread Starter

the machinist

Joined Apr 1, 2021
17
hi,
Did you try a LTS sim with the actual Inductive values.?
This is what I get.

Could you post your hand calculated results.
E
Heey sir it's me "cikalekli" (from turkey)
I just couldn't enter my previous account and that's why i needed to create a new one to ask a question.
I hope u re still doing ok during pandemic.
I just got the 2nd vaccine as well and hope i won't get in some troubles with the virus.
 
Top