View source for ESim/C2/Simulating-an-Astable-Multivibrator/English

'''Simulating Astable Multivibrator'''

'''Author: Saurabh Bansode '''

'''Keywords: video tutorial, eSim, EDA, schematic, simulation, Design, Spice models, ngspice, kicad, analysis, transient'''


{| border="1"
|-
| style="color:#000000;" | '''Visual cue'''
| style="color:#000000;" | '''Narration'''
|-
||   '''Show Slide:'''

Opening Slide
||   Welcome to the spoken tutorial on '''Simulating Astable Multivibrator '''in '''eSim'''.
|-
||   '''Show Slide:'''

Learning Objectives
||   In this tutorial, we will -

* Create and '''simulate''' an '''Astable Multivibrator'''.
* Understand '''dot cir '''and '''dot cir dot out''' files.
* Observe and understand the '''Ngspice terminal'''.

|-
||   '''Show Slide:'''

Systems Requirements
||   To record this tutorial, we will use-
* '''Ubuntu Linux OS '''16.04 
* '''eSim '''version 1.1.2

|-
||   '''Show Slide:'''

Prerequisites
||   To practice this tutorial, basic knowledge of electronics is required.
|-
||   '''Show Slide:'''

Circuit Diagram
||   Earlier, we learnt how to create a '''schematic''' for an''' RC circuit.'''


Now I am going to reinforce the idea with an '''Astable Multivibrator circuit.'''


The '''Astable Multivibrator circuit''' is as shown. 


Watch me for the next one minute as I create this '''circuit''' in '''eSim'''.
|-
||   <<'''FAST-FORWARD'''>>
||   A considerable part of this activity has been fast forwarded. 

|-
||During the demo....
||I am placing a few '''components''' and making a few connections.


It is expected that you know how to create a '''schematic''' in '''eSim'''.


In case you do not know, please watch the prerequisite '''eSim''' tutorials.
|-
||   '''Show Slide:'''

Download Code File
||   The partially made '''circuit schematic''' is available in the '''Code files link'''.


Pause the video to download and extract the '''code files''' on your '''Desktop.'''


We will use the downloaded '''code file''' to practice the rest of the tutorial.
|-
||   '''eSim Main Window:'''
||   Launch '''eSim '''on your machine.


I have already opened '''eSim.'''
|-
||   Click on''' Open Project '''>>Browse To '''Desktop''' >>click on '''AstableMultivibrator>>'''click on '''Open'''
||   Click on '''Open Project '''button on the left toolbar.


Browse to the '''Desktop''' location and click on '''AstableMultivibrator.'''


Then click on the '''Open '''button.
|-
||   '''eSim Main Window:'''

Click on''' Open Schematic'''
||   Click on the''' Open Schematic''' button on the left toolbar. 
|-
||   '''Schematic Editor Window:'''

Press F1 to zoom in.

||   Press the '''F1 '''key to zoom into the '''schematic'''.


If you have zoomed in or zoomed out too much, fit the '''schematic''' back to default.

|-
||Press '''Esc '''key >> click on '''View '''>> select '''Fit on Screen'''


||To do this, press the '''Esc''' key, and click on the '''View '''option on the top toolbar.


Select the '''Fit on Screen '''option.


It will fit the '''schematic''' back to its default resolution.

I will zoom in again.
|-
||   Point to the connections
||   Several connections are already made.
|-
||   '''eSim Schematic''' window:

Hover the mouse over the end points of''' eSim_LED '''and''' eSim_R '''present on the right hand side of the schematic.
||   The wires should be connected end-to-end for '''components''', and not external '''outlines'''.
|-
||   
||   I will demonstrate a common mistake now.
|-
||   '''eSim Schematic Editor:'''

Select the '''Place Wire''' tool from right toolbar.


Click on unconnected resistor, on the right side of the '''schematic'''.


Drag cursor till the horizontal line of the '''eSim_LED'''
||   Select the '''Place Wire''' tool.


I have clicked on one end of '''eSim underscore R'''.


I will drag it to the exterior outline of the '''eSim underscore LED''' and double-click.
|-
||   '''eSim Schematic Editor:'''

Zoom and point to the empty square block.


Press '''Ctrl+Z'''
||   The empty green box shows that the connection is not proper.


Press '''Ctrl''' and '''Z''' keys simultaneously to undo the changes just made.
|-
||   
||   Let us properly connect the '''eSim_LED''' present on the right side of the '''schematic'''.
|-
||   '''Schematic Editor Window:'''

Click on '''Place Wire''':
||   Click on '''Place Wire '''tool on the right toolbar.
|-
||   Click on unconnected node of the '''resistor'''

>>

Drag cursor till the''' Node 1''' of '''eSim_LED'''>>
||   Click on the unconnected '''node''' of the '''resistor'''.

Then drag the cursor till '''node 1''' of '''eSim underscore LED'''
|-
||   Click once on the '''eSim_R''' node

Press '''Esc''' key
||   Click once on the''' eSim underscore LED node '''to place the wire.

Press '''Esc''' key.
|-
||   '''Schematic Editor Window:'''

Click on '''Place Wire''':

>>Click on '''Node 2 '''of '''eSim_LED'''

>> Drag the cursor till the wire connecting adjacent '''transistor '''and '''capacitor'''>>Click once on the existing wire >> press the '''Esc''' key
||   Select the '''Place Wire''' tool and click on the''' node 2''' of '''eSim underscore LED'''.

Drag the cursor till the wire connecting the adjacent '''transistor''' and '''capacitor'''.


Click once on the existing wire.

Now press the '''Esc''' key.
|-
||   '''Schematic''' '''Editor''':

Zoom into the '''junction''' and hover the mouse over it.
||   If the wires are placed properly, you will see a green dot where the wires intersect.

This is called a '''junction'''.
|-
||   '''Schematic Editor''':

Right click on''' plot_v1'''

'''>>'''Select '''Copy Component '''>>Click once on the editor.
||   Right-click on''' plot underscore v1 '''and select the''' Copy component''' option.

'''plot underscore v1 '''will be tied to the cursor.
|-
||   Drag the cursor near the '''LED '''on the right side>>click once to Place it next to the''' LED'''
||   Drag the cursor near the '''LED '''on the right side.

Place it next to the''' LED '''by clicking once on the '''editor'''.
|-
||   '''Schematic Editor:'''

Select '''Place Global Label''' option from the right toolbar >>click once on editor>>

Enter '''LED2'''>>Click '''OK'''>>
||   Click on '''Place Global Label''' on the right toolbar, to place a '''global label'''.

Click once on the '''editor''' screen.

Type the text '''LED2 '''and click on''' OK.'''

'''LED2 global label '''will be tied to the cursor.
|-
||   Click once near the''' LED'''.
||   Place the '''LED2 global label''' near the''' LED '''on the right side, by clicking once on the '''editor''' once.

Rotate the '''global label''' if required.
|-
||   '''Schematic Editor:'''

Right click on '''eSim_CP1'''>>

Choose''' Edit Component'''>>

choose''' Value >> '''

erase '''eSim_CP1''' and type '''22u'''

'''>>'''Click on''' OK'''
||   Right-click on '''eSim_CP1'''.


Choose the '''Edit Component''' option, and select '''Value.'''


Erase the value '''eSim underscore CP1 '''using '''Backspace''' key and type''' 22u.'''


Click on '''OK.'''


Note that we are using '''polarised capacitor'''.
|-
||   '''Schematic Editor:'''

Place cursor on '''eSim_R'''>>

Press the key '''V >> '''erase '''eSim_R''' and type '''1k'''

'''>>'''

Click on '''OK'''
||   Right-click on '''eSim underscore R'''.


Place the cursor on '''Edit Component''', and select the '''Value''' option.


Erase the value '''eSim underscore R '''using '''Backspace''' key and type''' 1k.'''


Click on '''OK.'''
|-
|| '''Schematic Editor:'''

Hover mouse over''' DC''' source 
|| We will assign a value to the''' DC source''' later.
|-
||   '''Schematic Editor:'''

'''Select Place wire tool>> Click on plot_v1, drag till junction>>click once>>click once on LED2>>drag till junction and click once'''
|| Connect '''plot_v1 '''and '''LED2 global label '''to the '''junction''' as shown.

|-
||Press '''Ctrl''' and '''S''' keys simultaneously
||Press '''Ctrl''' and '''S''' keys simultaneously to save the work.
|-
|| '''Schematic Editor:'''

Click on '''Annotate Schematic'''>>

Click on '''Annotate''' >> Click '''OK>> '''Press '''Ctrl''' and '''S''' keys simultaneously
||   Click on '''Annotate Schematic''' tool on the top toolbar.


Click on '''Annotate''' option, and then on '''OK'''.

Press '''Ctrl''' and '''S''' keys simultaneously to save the work.
|-
||   '''Schematic Editor:'''

Click on''' Perform electrical Rules check >>'''Click on''' Run'''
||   Click on''' Perform electrical rules check '''on the top toolbar.


Click on '''Run.'''
|-
||   '''ERC Window:'''

Click''' Delete markers>>'''

Click''' Close'''
||   We can see three warnings regarding '''global label''', which can be ignored.


Click on '''Delete Markers''' and then click on '''Close.'''


More information on '''ERC errors''' is given in the '''Additional Reading Material '''of this tutorial.
|-
||   '''Schematic Editor WIndow:'''

Click '''Generate netlist''' >>
||   Click on '''Generate Netlist''' on the top toolbar.
|-
||   '''Generate Netlist WIndow:'''

'''spice''' tab >> check '''Default''' >> click on '''Generate '''>> Click''' Save.'''
||   Click on '''Spice''' tab, and check the '''Default Format''' option.


Then click on '''Generate''' option, and click on '''Save'''.
|-
||   
||   Now I will switch back to''' eSim '''main window.
|-
||   '''eSim Main window:'''

Double click on''' AstableMultivibrator>>'''

Click on''' KicadtoNgspice'''
||   Double-click on '''AstableMultivibrator.'''


Click on''' Convert Kicad to Ngspice convertor.'''
|-
||   '''Kicad to Ngspice Converter:'''

'''Analysis Tab'''

Show: 


Highlight the values entered.

'''Start Time 0'''

'''Step Time 10 milliseconds'''

'''Stop Time 12'''
||   Type the values for '''transient parameters''' as shown.
|-
||   '''Kicad to ngspice convertor '''window: '''Click on '''source details''' tab
||   Click on the '''Source details''' tab.
|-
||   '''Kicad to ngspice convertor '''

'''Window:'''

'''Source Details Tab'''
||   Type the value of '''DC source''' as '''9'''.


You should enter only numeric values of '''voltages'''.
|-
||   '''Kicad to Ngspice Converter:'''

'''Device Modeling''' tab:


Click on '''Add''' >> Double click on '''Diode''' folder >> select '''LED.lib '''>> click on '''Open'''
||   Click on '''Device Modeling '''tab.


Click on the '''Add''' button under '''d1:esim underscore led.'''


Double-click on '''Diode''' folder, select '''LED.lib''' file and click on the '''Open''' button.
|-
||   
||   Similarly add the '''library files''' for '''d2:esim underscore led'''
|-
||   '''Kicad to Ngspice Converter:'''

'''Device Modeling tab:'''

Click on '''Add''' >> Double click on '''Transistor''' folder >> select '''BC547B.lib''' >> click on '''Open'''
||   Click on the '''Add''' button under '''q1:esim underscore npn.'''


Double-click on '''Transistor''' folder, select '''BC547B.lib''' and click on the '''Open''' button.
|-
||   
||   Similarly add the '''library files''' for '''q2:esim_npn'''
|-
||   '''Kicad to Ngspice Converter:'''

'''Device Modeling '''tab:

Click on '''Convert '''>> Click''' OK'''
||   Now press the '''Convert '''button to convert the''' KiCad netlist '''to''' Ngspice netlist.'''


A confirmation dialog box appears, click on '''OK.'''
|-
||   '''eSim Main Window:'''

Click on '''Simulation.'''
||   Click on '''Simulation '''button on the '''eSim '''toolbar to simulate the example.
|-
||   '''Ngspice Terminal:'''


Highlight the '''LED1''' node and its voltage value.
||   '''Ngspice terminal '''and '''plot '''windows open along with a '''Python plot''' window.


'''Ngspice terminal''' shows the values of the '''voltages''' at the '''nodes'''.
|-
||   


Type '''plot v(LED1)+v(LED2)''' >> press '''Enter'''.
||   '''Ngspice commands''' can be entered to see plots in this '''terminal'''.


Type the following text in the '''Ngspice terminal''' and press the '''Enter''' key.
|-
||   Hover the mouse over '''LED1+LED2 '''voltage plots.
||   We can see the '''voltage''' at '''nodes LED1 '''and''' LED2 '''combined in a single plot.
|-
||   
||   Any error will be displayed on the''' Ngspice terminal''' or the value will be replaced with a question mark.
|-
||   
||   I will switch to '''Python Plot''' window.
|-
|| '''Python Plot Window:'''

Click on '''LED1, LED2 '''and''' IN.'''

'''>>'''Click on '''plot.'''
|| Click on''' LED1, LED2 '''and''' IN '''check-boxes in the '''Python plot''' window.


Scroll down and click on the '''Plot''' button.
|-
|| 
|| If '''analysis time parameters''' are not set properly, '''Python Plotting''' error will be generated.


For this particular '''circuit, step time''' is in '''milliseconds'''.
|-
||   '''eSim Main Window:'''


Right click on '''AstableMultivibrator'''>> select the '''refresh''' option>>Double-click on '''AstableMultivibrator.cir '''
||   Right-click on '''AstableMultivibrator''' and select the '''Refresh''' option.


The '''dot cir''' file shows the '''netist '''file of the '''schematic'''. 


It contains the information about the '''node''' connections and values of '''components'''.
|-
|| '''eSim Main Window:'''

Double click on '''AstableMultivibrator.cir.out''' 



Highlight the '''.tran 10e-03 12e-00 0e-00''' text
|| The '''cir dot out''' file is passed to '''ngspice''' for running '''simulations'''.


It contains information about the '''device''' and '''subcircuit models''' used in the''' KiCad to Ngspice '''conversion tool. 


It also contains the '''analysis time parameters'''.
|-
||   
|| Let us summarize.
|-
|| '''Show Slide: '''

Summary
||In this tutorial, we learnt to-
* Create and '''simulate''' an '''Astable Multivibrator.'''
* Understand '''dot cir '''and '''dot cir dot out''' files.
* Observe and understand the '''Ngspice terminal'''.

|-
||'''Show Slide:'''

'''Forum'''
|| Please post your timed queries in this forum. 
|- 
|| '''Show Slide:'''

'''FOSSEE Forum'''
|| Please post your general queries on '''eSim''' in this forum.
|- 
|| '''Show Slide:'''

'''Lab Migration'''
|| '''FOSSEE''' team coordinates the '''Lab Migration''' project.
|- 
|| '''Show Slide:'''

'''Circuit Simulation Project'''
||'''FOSSEE''' team coordinates the '''Circuit Simulation''' project.
|-
||'''Show Slide:'''

Acknowledgment


https://spoken-tutorial.org
||Spoken Tutorial Project is funded by NMEICT, MHRD, Govt. of India.


For more details, visit this website.
|-
||   

Previous slide
||This is Saurabh from IIT Bombay, signing off.

Thank you.
|-
|}