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

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| '''Time'''
| '''Narration'''

|-
|00:01
|Welcome to the spoken tutorial on '''Simulating Astable Multivibrator '''in '''eSim'''.

|-
| 00:07
| In this tutorial, we will -

Create and '''simulate''' an '''Astable Multivibrator'''.

Understand '''dot cir '''and '''dot cir dot out''' files and

Observe and understand the '''Ngspice terminal'''.

|-
|00:24
|   To record this tutorial, we will use-

'''Ubuntu Linux OS '''16.04 and

'''eSim '''version 1.1.2

|-
|00:36
|To practice this tutorial, basic knowledge of electronics is required.

|-
|00:41
|Earlier, we learnt how to create a '''schematic''' for an''' RC circuit.'''

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|00:47
|  Now I am going to reinforce the idea with an '''Astable Multivibrator circuit.'''

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|00:53
|  The '''Astable Multivibrator circuit''' is as shown. 

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|00:57
|Watch me for the next one minute as I create this '''circuit''' in '''eSim'''.

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|01:04
|A considerable part of this activity has been fast forwarded. 

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|01:49
|I am placing a few '''components''' and making a few connections.

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|01:54
|  It is expected that you know how to create a '''schematic''' in '''eSim'''.

|-
|01:59
|  In case you do not know, please watch the prerequisite '''eSim''' tutorials.

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|02:50
|  The partially made '''circuit schematic''' is available in the '''Code files link'''.

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|02:55
|  Pause the video to download and extract the '''code files''' on your '''Desktop.'''

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|03:01
|  We will use the downloaded '''code file''' to practice the rest of the tutorial.

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|03:06
|Launch '''eSim '''on your machine.

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|03:09
|  I have already opened '''eSim.'''

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|03:12
| Click on '''Open Project '''button on the left toolbar.

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|03:17
|  Browse to the '''Desktop''' location and click on '''AstableMultivibrator.'''

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|03:23
|  Then click on the '''Open '''button.

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|03:26
| Click on the''' Open Schematic''' button on the left toolbar. 

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|03:31
|Press the '''F1 '''key to zoom into the '''schematic'''.

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|03:35
|  If you have zoomed in or zoomed out too much, fit the '''schematic''' back to default.

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|03:41
|To do this, press the '''Esc''' key, and click on the '''View '''option on the top toolbar.

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|03:49
|  Select the '''Fit on Screen '''option.

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|03:53
|  It will fit the '''schematic''' back to its default resolution. I will zoom in again.

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|04:03
|The wires should be connected end-to-end for '''components''', and not external '''outlines'''.

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|04:11
|I will demonstrate a common mistake now.

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|04:14
|Select the '''Place Wire''' tool.

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|04:17
|  I have clicked on one end of '''eSim underscore R'''.

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|04:22
|  I will drag it to the exterior outline of the '''eSim underscore LED''' and double-click.

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|04:29
|   The empty green box shows that the connection is not proper.

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|04:34
|  Press '''Ctrl''' and '''Z''' keys simultaneously to undo the changes just made.

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| 04:40
| Let us properly connect the '''eSim_LED''' present on the right side of the '''schematic'''.

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|04:46
|Click on '''Place Wire '''tool on the right toolbar.

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|04:50
|   Click on the unconnected '''node''' of the '''resistor'''. Then drag the cursor till '''node 1''' of '''eSim underscore LED'''

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|05:00
|Click once on the''' eSim underscore LED node '''to place the wire. Press '''Esc''' key.

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|05:07
|Select the '''Place Wire''' tool and click on the''' node 2''' of '''eSim underscore LED'''.

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|05:16
|  Drag the cursor till the wire connecting the adjacent '''transistor''' and '''capacitor'''.

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|05:22
|  Click once on the existing wire. Now press the '''Esc''' key.

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|05:28
|If the wires are placed properly, you will see a green dot where the wires intersect.
This is called a '''junction'''.

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|05:37
|Right-click on''' plot underscore v1 '''and select the''' Copy component''' option.

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|05:44
|  '''plot underscore v1 '''will be tied to the cursor.

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|05:48
|Drag the cursor near the '''LED '''on the right side.

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|05:53
|  Place it next to the''' LED '''by clicking once on the '''editor'''.

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|05:58
|Click on '''Place Global Label''' on the right toolbar, to place a '''global label'''.

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|06:04
|  Click once on the '''editor''' screen. Type the text '''LED2 '''and click on''' OK.''' 

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|06:14
|  '''LED2 global label '''will be tied to the cursor.

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|06:18
| Place the '''LED2 global label''' near the''' LED '''on the right side, by clicking once on the '''editor''' once.

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|06:25
|  Rotate the '''global label''' if required.

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|06:30
|Right-click on '''eSim_CP1'''.

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|06:34
|  Choose the '''Edit Component''' option, and select '''Value.'''

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|06:39
|  Erase the value '''eSim underscore CP1 '''using '''Backspace''' key and type''' 22u.''' Click on '''OK.'''

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|06:49
|  Note that we are using '''polarised capacitor'''.

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|06:53
| Right-click on '''eSim underscore R'''.

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|06:57
|  Place the cursor on '''Edit Component''', and select the '''Value''' option.

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|07:04
|  Erase the value '''eSim underscore R '''using '''Backspace''' key and type''' 1k.''' Click on '''OK.'''

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|07:13
|We will assign a value to the''' DC source''' later.

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|07:18
| Connect '''plot_v1 '''and '''LED2 global label '''to the '''junction''' as shown.

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|07:28
|Press '''Ctrl''' and '''S''' keys simultaneously to save the work.

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|07:33
|Click on '''Annotate Schematic''' tool on the top toolbar.

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|07:38
|  Click on '''Annotate''' option, and then on '''OK'''.

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|07:43
|  Press '''Ctrl''' and '''S''' keys simultaneously to save the work.

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|07:48
|Click on''' Perform electrical rules check '''on the top toolbar. Click on '''Run.'''

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|07:55
|We can see three warnings regarding '''global label''', which can be ignored.

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|08:02
|  Click on '''Delete Markers''' and then click on '''Close.'''

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|08:08
|  More information on '''ERC errors''' is given in the '''Additional Reading Material '''of this tutorial.

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|08:15
|   Click on '''Generate Netlist''' on the top toolbar.

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|08:20
|   Click on '''Spice''' tab, and check the '''Default Format''' option.

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|08:26
|  Then click on '''Generate''' option, and click on '''Save'''.

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|  08:32
|Now I will switch back to''' eSim '''main window.

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|08:36
|Double-click on '''AstableMultivibrator.'''

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|08:40
|  Click on''' Convert Kicad to Ngspice convertor.'''

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|08:44
| Type the values for '''transient parameters''' as shown.

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|08:49
|Click on the '''Source details''' tab.

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|08:52
|Type the value of '''DC source''' as '''9'''. You should enter only numeric values of '''voltages'''.

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|09:02
| Click on '''Device Modeling '''tab.

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|09:05
|  Click on the '''Add''' button under '''d1:esim underscore led.'''

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|09:11
|  Double-click on '''Diode''' folder, select '''LED.lib''' file and click on the '''Open''' button.

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|09:20
|Similarly add the '''library files''' for '''d2:esim underscore led'''

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|09:26
|Click on the '''Add''' button under '''q1:esim underscore npn.'''

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|09:33
|  Double-click on '''Transistor''' folder, select '''BC547B.lib''' and click on the '''Open''' button.

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|09:42
|Similarly add the '''library files''' for '''q2:esim_npn'''

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|09:50
|Now press the '''Convert '''button to convert the''' KiCad netlist '''to''' Ngspice netlist.'''

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|09:56
|  A confirmation dialog box appears, click on '''OK.'''

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|10:01
|Click on '''Simulation '''button on the '''eSim '''toolbar to simulate the example.

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|10:08
|'''Ngspice terminal '''and '''plot '''windows open along with a '''Python plot''' window.

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|10:15
|  '''Ngspice terminal''' shows the values of the '''voltages''' at the '''nodes'''.

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|10:21
|'''Ngspice commands''' can be entered to see plots in this '''terminal'''.

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|10:27
|  Type the following text in the '''Ngspice terminal''' and press the '''Enter''' key.

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|10:34
|We can see the '''voltage''' at '''nodes LED1 '''and''' LED2 '''combined in a single plot.

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|10:43
|Any error will be displayed on the''' Ngspice terminal''' or the value will be replaced with a question mark.

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|10:50
|I will switch to '''Python Plot''' window.

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|10:53
|Click on''' LED1, LED2 '''and''' IN '''check-boxes in the '''Python plot''' window.

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|11:02
|  Scroll down and click on the '''Plot''' button.

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|11:06
|If '''analysis time parameters''' are not set properly, '''Python Plotting''' error will be generated.

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|11:13
|  For this particular '''circuit, step time''' is in '''milliseconds'''.

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|11:18
|Right-click on '''AstableMultivibrator''' and select the '''Refresh''' option.

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|11:24
|  The '''dot cir''' file shows the '''netist '''file of the '''schematic'''. 

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|11:29
|  It contains the information about the '''node''' connections and values of '''components'''.

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|11:35
|The '''cir dot out''' file is passed to '''ngspice''' for running '''simulations'''.

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|11:41
|  It contains information about the '''device''' and '''subcircuit models''' used in the''' KiCad to Ngspice '''conversion tool. 

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|11:49
|  It also contains the '''analysis time parameters'''.

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| 11:53
| Let us summarize.

|-
|11:55
|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'''.

|-
|12:11
| Please post your timed queries in this forum. 

|- 
|12:15
|Please post your general queries on '''eSim''' in this forum.

|- 
|12:20
| '''FOSSEE''' team coordinates the '''Lab Migration''' project.

|- 
|12:24
|'''FOSSEE''' team coordinates the '''Circuit Simulation''' project.

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|12:29
|Spoken Tutorial Project is funded by NMEICT, MHRD, Govt. of India. For more details, visit this website.

|-
|12:36
|This is Saurabh from IIT Bombay, signing off. Thank you.

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