Difference between revisions of "Ngspice/C2/DC-Sweep-Analysis/English-timed"

!Time  

!Narration  

|  Welcome to this '''spoken tutorial''' on “'''DC sweep analysis in Ngspice'''”.

|* To perform '''DC sweep analysis''' and '''Nested DC sweep analysis.'''

| The circuit consists of three prominent '''nodes'''- “1”, “2” and “3”.  

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

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

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

| ''' 'dc' command''' included in the '''netlist''' file is used to perform '''dc sweep analysis'''.

|  General form to use ''''dc' command''' is as shown:

| Now I go to the '''folder''' where the '''netlist''' '''file,''' '''example.cir,''' is '''saved.'''

| '''cd downloads path to the folder '''and press '''Enter.'''

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

| On '''terminal,'''

 

| Type '''ngspice '''space''' example.cir''' and press '''Enter.'''

| Value of '''voltage''' v1 is 24 '''volts.'''

| Value of '''voltage''' v2 is 9.746 '''volts.'''

| Other '''node''' '''voltages''' are also displayed.

|   Next we will see how to do '''nested dc sweep analysis.'''

| where,

| '''SRCNAM''' is the primary '''sweep''' '''variable''' and '''SRC2''' is the secondary '''sweep''' '''variable.'''

| Secondary '''sweep''' '''variable''' forms the outer loop.  

| That is for every increment of secondary '''sweep variable,''' the first '''sweep variable''' is stepped through its entire range of values.

| It will be more clear with the example '''circuit''' we will '''simulate.'''

|  We will use '''Bipolar junction transistor '''based '''circuit''' in '''common base''' configuration.  

| Primary '''sweep variable''' is '''voltage''' '''Vin''' connected between '''emitter''' and '''base''' '''terminals.'''

| Secondary '''sweep''' '''variable''' will be the '''load''' '''resistor''' '''Rload.'''

| We will '''plot''' '''output voltage '''versus '''input voltage '''for different values of the '''load resistor'''.

| The output voltage is the voltage across Rload and the input voltage is '''Vin'''

| '''NPN''' is the '''default''' '''model''' used for '''transistor,''' '''mod1''', in the '''circuit.'''

| As you can see Vin is varied from 0.2 '''volts''' to 2 '''volts''' with step increment of 0.02 '''volts.'''

| '''Rload''' is varied from '''5kiloohms''' to 10 '''kiloohms''' with step increment of '''2kiloohms'''

| For different values of '''Rload, Vin''' is swept through the complete range of 0.2 to 2.  

| Graphs of '''output''' '''voltage''' versus '''input''' '''voltage''' is plotted in each case.

| '''Plot v of 3,4''' plots the '''voltage''' '''drop''' between the '''nodes''' 3 and 4, that is the '''voltage''' across '''Rload.'''

| Now we will '''simulate''' this '''circuit''' and see the results.

| On the '''terminal''' type '''source space example nested.cir '''and press '''Enter.'''

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

|  As you can see graph of '''output voltage''' versus '''input voltage''' is plotted for different values of '''load''' '''resistor.'''

| Quit the '''ngspice''' '''simulator''' by typing '''quit''' and press '''enter.'''

| Here we come to the end of this '''tutorial'''

| In this tutorial we learnt,

| To perform,

 

| 06:08

| Nested DC sweep analysis of a given circuit.  

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| Hope you found this tutorial useful.  

| This is Anuradha Amrutkar signing off.