Difference between revisions of "Ngspice/C2/Operating-point-analysis-in-NGspice/English-timed"

| Dear Friends, Welcome to this spoken tutorial on “'''Operating point analysis'''" in ngspice.

| In this tutorial we will learn,

| 00:10

| To perform '''operating''' '''point''' '''analysis.'''

| 00:13

| To verify '''Kirchoff's''' '''voltage''' '''law''' using '''ngspice''' in,'''interactive mode command-line interface and''' '''commandscript included in netlist file.'''

| '''Ubuntu''' 12.04 is the '''operating system''' used with '''ngspice version''' 23 '''installed.'''

|   00:33

|   Basic knowledge of '''electronic''' '''circuits''' is a prerequisite for this tutorial.

|   00:38

| Basic knowledge of '''Ubuntu''' '''Linux''' and '''shell''' '''commands''' is also required.

|   00:43

|   We will use the example '''circuit''' shown.

|   00:47

| The '''circuit''' consists of three prominent '''nodes'''  

|“a”,  

 

|   00:55

| and “c”.  

| In addition, a fourth '''node''' called as '''reference''' or the '''datum''' '''node''' must be marked as '''node''' “0”.  

|   01:06

| This is mandatory for any '''circuit.'''

| 01:09  

|   Let us open the '''ngspice''' '''netlist''' '''example1.cir''' '''file''' corresponding to the '''circuit''' '''schematic''' shown before, in a '''text''' '''editor.'''

| 01:19  

| I have already opened this in '''gedit''' '''text''' '''editor.'''

| 01:27

| Note that the '''netlist''' '''file''' is saved with '''.cir''' '''extension'''  

| We can see all the '''components''' like '''voltage source, resistors''' and '''current source'''.

| Also the information about '''nodes''' connecting them together.

| ''' .op command''' included in '''netlist''' '''file''' is used to perform '''operating point analysis'''

| Now we will '''simulate''' this '''circuit,''' and verify '''Kirchoff's''' '''voltage''' '''law''' using the '''interactive mode-command-line interface.'''

| let us open '''ngspice''' through '''terminal.'''  

| Go to top left corner of '''Ubuntu''' '''desktop''' '''screen.'''

| In the '''search bar,''' write '''terminal''' and press '''Enter.'''

| This will open '''Terminal''' '''window.'''

| Let me resize this window

| Now I will go to the '''folder''' where the '''netlist''' '''file''' '''example1.cir''' is '''saved.'''

| On '''terminal,''' I will type '''cd space Desktop slash op hyphen analysis ''' and press '''Enter.'''

| Now let us '''simulate''' the '''ngspice''' '''file.'''

| On '''terminal,''' Type '''ngspice space example1.cir''' and press '''Enter.'''

| Here you will notice that we have entered into the '''ngspice''' '''command''' '''line interface'''.

| Type '''run''' and press '''Enter'''  

| This will '''simulate''' the '''circuit''' and '''store''' the results.

|   03:39   

|   According to '''Kirchoff's voltage law,''' '''voltage''' around outer loop should be equal to the value of the '''dc''' '''voltage''' '''source''' V1.

|   03:51

| Calculate '''voltage''' around the outer '''loop.'''  

|   03:54   

|   03:59

| In the '''ngspice''' '''command''' '''line interface''' on the '''Terminal''' ,

|   04:03

| Type '''print space v of a comma b plus v of b comma c plus v of c''' and press '''Enter''' Key

|   04:21

| Here '''v of a comma b''' denotes the''' voltage drop''' between the '''nodes''' a and b and so on.

|   04:29

| '''print command''' '''displays''' the results of the calculation mentioned to its right side.

|   04:36

| Notice the result of the '''calculation''' in the '''terminal.'''

|   04:39

| It is 30 '''volt''' as shown

|   04:42

| Now '''calculate''' the value of '''DC''' '''voltage''' '''source''' V1 that is v(a).

|   04:50

| Type '''print space v of a ''' and press '''Enter'''

| Notice the result of the '''calculation''' in the '''terminal.'''

| 05:04

| 05:10

| Since both '''voltage''' values are equal, the '''Kirchhoff's Voltage law''' is verified for outer loop ''' a,  b, c  and 0.

| Now we will '''simulate''' this '''circuit,''' and verify '''Kirchoff's voltage law''' using the '''command''' script included in the '''netlist file'''.

| Modified '''netlist''' '''file''' '''example hyphen modified dot cir''' is as shown

|  As you can see all the '''commands''' we executed in '''command-line interface''' are included in this '''netlist''' as '''control''' '''statements.'''

| '''Echo''' command will '''echo''' the text written to its right side, on the '''terminal''' '''window.'''

| Now we execute the modified '''netlist''' '''file.'''

| '''source''' command is used to '''simulate''' the '''netlist''' from within the '''ngspice simulator environment'''

| On the '''terminal''' type '''source space example hyphen modified dot cir''' and press the'''Enter key.'''

| This will run the '''simulation''' and directly show the results for '''KVL''' verification.  

|  Now let us summarize what we learnt in this tutorial.

| In this tutorial we learnt,

| To verify '''Kirchhoff's voltage law''' using '''ngspice''' through '''interactive mode-command line interface ''', '''commandscript''' included in the '''netlist''' file.

| Watch the video available at the following link  

|  It summarises the Spoken Tutorial project  

| If you do not have good bandwidth, you can download and watch it  

|  The Spoken Tutorial Project Team

| Conducts workshops using spoken tutorials  

| Gives certificates for those who pass an online test  

|  For more details, please write to '''contact at spoken hyphen tutorial dot org '''

| Spoken Tutorial Project is a part of the Talk to a Teacher project  

| More information on this Mission is available at  

| spoken hyphen tutorial dot org slash NMEICT hyphen Intro  

| This script is contributed by Abhishek Pawar and this is Rupak Rokade from IIT Bombay signing off.