Difference between revisions of "Ngspice/C2/DC-Sweep-Analysis/English-timed"
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{| border=1 | {| border=1 | ||
| − | + | |'''Time''' | |
| − | + | |'''Narration''' | |
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| 00:01 | | 00:01 | ||
| − | | Welcome to this '''spoken tutorial''' on | + | | Welcome to this '''spoken tutorial''' on '''DC sweep analysis in Ngspice'''. |
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| 00:36 | | 00:36 | ||
| − | | The circuit consists of three prominent '''nodes'''- | + | | The circuit consists of three prominent '''nodes'''- '''1, 2 and 3'''. |
|- | |- | ||
| 00:40 | | 00:40 | ||
| − | | In addition, a fourth '''node''' called as '''reference''' OR '''datum node''' must be marked as node “0”. | + | | In addition, a fourth '''node''' called as '''reference''' OR '''datum node''' must be marked as node '''“0”'''. |
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| 00:51 | | 00:51 | ||
| − | | Let us open the '''ngspice netlist''' file "example.cir" corresponding to the '''circuit schematic''' shown before, in the '''text editor'''. | + | | Let us open the '''ngspice netlist''' file '''"example.cir"''' corresponding to the '''circuit schematic''' shown before, in the '''text editor'''. |
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| 01:04 | | 01:04 | ||
| − | | Note that '''netlist''' file is saved with ".cir" '''extension'''. | + | | Note that '''netlist''' file is saved with '''".cir"''' '''extension'''. |
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| 01:18 | | 01:18 | ||
| − | | | + | | ''' dc command''' included in the '''netlist''' file is used to perform '''dc sweep analysis'''. |
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| 01:25 | | 01:25 | ||
| − | | General form to use | + | | General form to use '''dc command''' is as shown: |
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| − | | Now I go to the folder where the '''netlist''' file, | + | | Now I go to the folder where the '''netlist''' file, '''example.cir''', is saved. |
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| − | | The output voltage is the voltage across 'Rload' and the input voltage is 'Vin'. | + | | The output voltage is the voltage across '''Rload''' and the input voltage is '''Vin'''. |
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| 04:26 | | 04:26 | ||
| − | | | + | | '''NPN''' is the default model used for transistor "'''mod1'''", in the circuit. |
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| 04:45 | | 04:45 | ||
| − | | 'Rload' is varied from 5 '''kilo-ohms''' to 10 '''kilo-ohms''' with step increment of '''2 kilo-ohms'''. | + | | '''Rload''' is varied from 5 '''kilo-ohms''' to 10 '''kilo-ohms''' with step increment of '''2 kilo-ohms'''. |
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| 04:53 | | 04:53 | ||
| − | | For different values of 'Rload', 'Vin' is swept through the complete range of 0.2 to 2. | + | | For different values of '''Rload''', '''Vin''' is swept through the complete range of 0.2 to 2. |
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| − | | '''Plot v of 3 comma 4''' plots the '''voltage drop''' between the nodes 3 and 4, that is the voltage across 'Rload'. | + | | '''Plot v of 3 comma 4''' plots the '''voltage drop''' between the nodes 3 and 4, that is the voltage across '''Rload'''. |
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| 06:31 | | 06:31 | ||
| − | | For more details, please write to: | + | | For more details, please write to:'''contact at spoken hyphen tutorial dot org''' |
| − | '''contact at spoken hyphen tutorial dot org''' | + | |
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Revision as of 16:19, 3 January 2017
| Time | Narration |
| 00:01 | Welcome to this spoken tutorial on DC sweep analysis in Ngspice. |
| 00:07 | In this tutorial, we will learn: |
| 00:09 | To perform DC sweep analysis and Nested DC sweep analysis. |
| 00:14 | Basic knowledge of electronic circuits is a prerequisite for this tutorial. |
| 00:19 | Basic knowledge of Ubuntu Linux and shell commands is also required. |
| 00:25 | Ubuntu 12.04 is the operating system used with ngspice version 23 installed. |
| 00:33 | We will use the example circuit shown. |
| 00:36 | The circuit consists of three prominent nodes- 1, 2 and 3. |
| 00:40 | In addition, a fourth node called as reference OR datum node must be marked as node “0”. |
| 00:47 | This is mandatory for any circuit. |
| 00:51 | Let us open the ngspice netlist file "example.cir" corresponding to the circuit schematic shown before, in the text editor. |
| 01:00 | I have already opened this file in gedit text editor. |
| 01:04 | Note that netlist file is saved with ".cir" extension. |
| 01:10 | We can see all the components like voltage source, resistors and information about nodes connecting them together. |
| 01:18 | dc command included in the netlist file is used to perform dc sweep analysis. |
| 01:25 | General form to use dc command is as shown: |
| 01:29 | dot DC SRCNAM VSTART VSTOP VINCR |
| 01:35 | where |
| 01:37 | SRCNAM is name of independent voltage and current source. |
| 01:42 | VSTART, VSTOP and VINCR are the starting, final and increment values respectively, for the source. |
| 01:51 | As you see, we are sweeping voltage source V1 for a single value of 24 VOLTS with the step increment of 1. |
| 02:02 | Now, we will simulate this circuit and find out voltage values at different nodes. |
| 02:08 | Let us open ngspice through terminal. |
| 02:11 | Press Control, Alt, T together. |
| 02:14 | This will open the Terminal window. |
| 02:18 | Now I go to the folder where the netlist file, example.cir, is saved. |
| 02:23 | I do this as follows: |
| 02:26 | cd downloads path to the folder and press Enter. |
| 02:33 | Now, let us simulate the ngspice file. |
| 02:36 | Let us see how this can be done. |
| 02:39 | On terminal, |
| 02:40 | Type: ngspice space example.cir and press Enter. |
| 02:51 | Value of voltage v1 is 24 volts. |
| 02:56 | Value of voltage v2 is 9.746 volts. |
| 03:01 | Other node voltages are also displayed. |
| 03:05 | Next we will see how to do nested dc sweep analysis. |
| 03:10 | Generalized form for this is as shown. |
| 03:14 | Dot DC SRCNAM VSTART VSTOP VINCR SRC2 START2 STOP2 INCR2 |
| 03:24 | where |
| 03:26 | SRCNAM is the Primary sweep variable and SRC2 is the Secondary sweep variable. |
| 03:33 | Secondary sweep variable forms the outer loop. |
| 03:36 | That is, for every increment of secondary sweep variable, the first sweep variable is stepped through its entire range of values. |
| 03:45 | It will be more clear with the example circuit we will simulate. |
| 03:50 | We will use Bipolar junction transistor based circuit in common base configuration. |
| 03:56 | Primary sweep variable is voltage Vin, connected between emitter and base terminals. |
| 04:03 | Secondary sweep variable will be the load resistor 'Rload'. |
| 04:08 | We will plot output voltage versus input voltage, for different values of the load resistor. |
| 04:14 | The output voltage is the voltage across Rload and the input voltage is Vin. |
| 04:21 | Following is the netlist corresponding to the common base transistor circuit. |
| 04:26 | NPN is the default model used for transistor "mod1", in the circuit. |
| 04:33 | As you can see, 'Vin' is varied from 0.2 volts to 2 volts with step increment of 0.02 volts. |
| 04:45 | Rload is varied from 5 kilo-ohms to 10 kilo-ohms with step increment of 2 kilo-ohms. |
| 04:53 | For different values of Rload, Vin is swept through the complete range of 0.2 to 2. |
| 04:59 | Graphs of output-voltage versus input-voltage is plotted in each case. |
| 05:05 | Plot v of 3 comma 4 plots the voltage drop between the nodes 3 and 4, that is the voltage across Rload. |
| 05:15 | Now, we will simulate this circuit and see the results. |
| 05:19 | On the terminal, type: source space example nested.cir and press Enter. |
| 05:35 | This will run the simulation. |
| 05:37 | source command is used to simulate the netlist from within the ngspice simulator environment. |
| 05:44 | As you can see, graph of output-voltage versus input-voltage is plotted for different values of load resistor. |
| 05:52 | Quit the ngspice simulator by typing "quit" and press Enter. |
| 05:59 | Here, we come to the end of this tutorial. |
| 06:02 | In this tutorial, we learnt: |
| 06:04 | To perform- |
| 06:05 | * DC sweep analysis of a given circuit. |
| 06:08 | * Nested DC sweep analysis of a given circuit. |
| 06:12 | Watch the video available at the following link. |
| 06:14 | It summarizes the Spoken Tutorial project. |
| 06:18 | If you do not have good bandwidth, you can download and watch it. |
| 06:22 | The Spoken Tutorial project team: |
| 06:24 | * Conducts workshops using spoken tutorials. |
| 06:27 | * Gives certificates for those who pass an online test. |
| 06:31 | For more details, please write to:contact at spoken hyphen tutorial dot org |
| 06:37 | Spoken Tutorial is a part of the Talk to a Teacher project. |
| 06:41 | It is supported by the National Mission on Education through ICT, MHRD, Government of India. |
| 06:47 | More information on this mission is available at: |
| 06:51 | spoken hyphen tutorial dot org slash NMEICT hyphen Intro |
| 06:58 | Thank you for joining. |
| 06:59 | Hope you found this tutorial useful. |
| 07:02 | This is Anuradha Amrutkar, signing off. |
