Difference between revisions of "ESim/C2/Simulating-an-Astable-Multivibrator/English"

Opening Slide

Learning Objectives

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

Systems Requirements

• Ubuntu Linux OS 16.04
• eSim version 1.1.2

Prerequisites

Circuit Diagram

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.

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 tutorials.

Download Code File

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.

I have already opened eSim.

Browse to the Desktop location and click on AstableMultivibrator.

Then click on the Open button.

Click on Open Schematic

Press F1 to zoom in.

Press Esc key >> click on View >> select Fit on Screen

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

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

Select the Fit on Screen option.

It will fit the schematic back to its default resolution.

I will zoom in again.

Hover the mouse over the end points of eSim_LED and eSim_R present on the right hand side of the schematic.

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

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.

Zoom and point to the empty square block.

Press Ctrl+Z

Press Ctrl and Z keys simultaneously to undo the changes just made.

Click on Place Wire:

>>

Drag cursor till the Node 1 of eSim_LED>>

Then drag the cursor till node 1 of eSim underscore LED

Press Esc key

Press Esc key.

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

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

Click once on the existing wire.

Now press the Esc key.

Zoom into the junction and hover the mouse over it.

This is called a junction.

Right click on plot_v1

>>Select Copy Component >>

Click once on the editor.

plot underscore v1 will be tied to the cursor.

Place it next to the LED by clicking once on the editor.

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

Enter LED2>>Click OK>>

Click once on the editor.

Type the text LED2 and click on OK.

LED2 global label will be tied to the cursor.

Rotate the Global label if required.

Right click on eSim_CP1>>

Choose Edit Component>>

choose Value >>

erase eSim_CP1 and type 22u

>>Click on OK

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.

Place cursor on eSim_R>>

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

>>

Click on OK

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.

Hover mouse over DC source

Select Place wire tool>> Click on plot_v1, drag till junction>>click once>>click once on LED2>>drag till junction and click once

Click on Annotate Schematic>>

Click on Annotate >> Click OK>> Press Ctrl and S keys simultaneously

Click on Annotate option, and then on OK.

Press Ctrl and S keys simultaneously to save the work.

Click on Perform electrical Rules check >>Click on Run

Click on Run.

Click Delete markers>>

Click Close

Click on Delete Markers and then click on Close.

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

Click Generate netlist >>

spice tab >> check Default >> click on Generate >> Click Save.

Then click on Generate option, and click on Save.

Double click on AstableMultivibrator>>

Click on KicadtoNgspice

Click on Convert Kicad to Ngspice convertor.

Analysis Tab

Show:

Start Time 0

Step Time 10 milliseconds

Stop Time 12

Window: Click on source details tab

Window:

Source Details Tab

You should enter only numeric values of voltages.

Device Modeling tab:

Click on Add >> Double click on Diode folder >> select LED.lib >> click on Open

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.

Device Modeling tab:

Click on Add >> Double click on Transistor folder >> select BC547B.lib >> click on Open

Double-click on Transistor folder, select BC547B.lib and click on the Open button.

Device Modeling tab:

Click on Convert >> Click OK

A confirmation dialog box appears, click on OK.

Click on Simulation.

Highlight the LED1 node and its voltage value.

Ngspice terminal shows the values of the voltages at the nodes.

Type plot v(LED1)+v(LED2) >> press Enter.

Type the following text in the Ngspice terminal as shown and press the Enter key.

Click on LED1, LED2 and IN.

>>Click on plot.

Scroll down and click on Plot button.

For this particular circuit, step time is in milliseconds.

Right click on AstableMultivibrator>> select the refresh option>>Double-click on AstableMultivibrator.cir

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

It contains the information about the node connections and values of components.

Double click on AstableMultivibrator.cir.out

Highlight the .tran 10e-03 12e-00 0e-00 text

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

It also contains the analysis time parameters.

Summary

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

Forum

FOSSEE Forum

Lab Migration

Circuit Simulation Project

Acknowledgment

https://spoken-tutorial.org

For more details, visit this website.

Previous slide

Thank you.