Control System Theory and SPICE Simulation

Ing. Cristoforo Baldoni

This article provides the principles for the design and analysis of Feedback and Control Systems. The Control Systems are everywhere in the modern industrial technological world, in the laser positioning of a CD Reader,  in the very high precision positioning system of an hard disk head, and even our body has a large number of biological control systems. After introducing the basic concepts, we’ll see how easily evaluate the Open loop Transfer Function with PSPice.




1.  Processes, Open Loop and Closed Loop Control Systems (Feedback Systems)


2. Generic closed loop schematic of Feedback Systems


3. Physycal Processes Modeling, differential equations and calculations simplification with Laplace transform


4. Transfer Function, Poles and Zeros of a Transfer Function, phisical meaning


5. Natural and Forced Response, calculating Residues, when it’s possible simplify identical Zeros and Poles, dominant poles


6. Process Stability


7. Steady State Error, Type of Systems


8. Study of Transfer Function with Bode diagram. Study the Open Loop Transfer Function with SPICE.


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Altium Designer Video tutorials

Getting started with Altium Designer
What is a project in Altium Designer
Create a project and adding documents
How to create a schematic symbol in Altium Designer
How to wire a schematic in Altium Designer
Resolve ERC errors
How to create a PCB footprint in Altium Designer
Setting PCB footprints
keeping schematic and PCB synchronized in Altium Designer
How to place the components on the board
Routing the PCB
How to change the shape of PCB in Altium Designer
Layer stack and drill pairs

Getting Started with Altium Designer

In this article we are going to  draw a simple inverting op-amplifier with dual power supply to introduce the reader to the fundamental tools used in the Altium Designer suite.

Let’s begin creating a new schematic:

 a new blank sheet pops up


 on the top toolbar we find the icon to place part

The place part window appears

Click on the button “…” to open the Browse Libraries window

moving throughout the first list we can select a library

Once selected the library we can easily choose a library’s component

Getting Started with NI Multisim

For exploring some of the main features of this software we’  ll design an IC 20W power amplifier with a LM 1875T.

After running the program Multisim opens the default capture and simulation environment:


Now let’s select the components for our amplifier

The Component Browser dialog window appears, the components are organized into Groups and Families:

In the same Component Browser window, under the label “Components”, we can search a component editing its name, in this case LM1875T

Arduino Simulation with Proteus

We ‘ll show how to simulate the celebrated open-source electronics prototyping platform Arduino with Proteus .

 Let ‘s run ISIS Schematic:


To simulate the core of Arduino platform we need only a few components: the atmega328P Microcontroller, a Crystal and two Capacitors.Let’ s look for these devices in the library:

Click on “P” button and write atmega as keyword:


Double click on the model and this appears under Devices panel:

Same operations for the Crystal and Capacitor:



Getting Started with Proteus

Thanks for this article to archeng504


After installing Proteus , run ISIS Proteus Professional, will appear the following window interface :



Following is a brief description of each part of the function :

1. Schematic Editor window (The Editing Window): As the name implies , it is used to draw the schematic . Blue box as editable area, to put it inside the component . Note that this window is no scroll bar , you can use the preview window to change the schematic visual range .

2. Preview window (The Overview Window): It shows the two elements, one is this: When you are in the component list, select a component, it will show a preview of the element ; Another is that when you mouse focus falls on the principle diagram editor window ( ie, place the component into the schematic editor window Or after the Schematic Editor window, click the mouse ) , it will display the entire schematic diagram of the thumbnails, and will show a green box , green box which is the content of the current diagram window displays the contents of Therefore, you use the mouse to click on it to change the location of the green box , thereby changing the schematic visual range.




3. Model Selection Toolbar (Mode Selector Toolbar):

Main Modes:

1 * Select elements (components) ( selected by default )

2 * Place the connection point

3 * place a label ( the bus will be used )

4 * Place text

5 * for drawing bus

6 * for placing subcircuits

7 * for instant editing component parameters ( first click on the icon and then click the element you want to modify )


1 * terminal interface (terminals): There VCC, ground , output, input and other interfaces

2 * Device Pin : for drawing pin

3 * Emulation chart (graph): used for various analyzes, such as Noise Analysis

4 * recorder

5 * signal generator (generators)

6 * Voltage Probe: to be used when using simulation charts

7 * current probe : Using simulation to be used when using simulation charts

8 * Virtual Instrument :  in the image above, an oscilloscope

2D graphics (2D Graphics):

1 * Drawing Lines

2 * draw a variety of boxes

3 * draw various circles

4 * draw a variety of arc

5 * draw various polygons

6 * draw various text

7 * draw symbols

8 * paintings origin , etc.

4 . Component List (The Object Selector):

For the selection of components (components), terminal interface (terminals), the signal generator (Generators), simulation chart (graph) and so on. For example , when you select ” Component (Components) “, click the ” P ” button will open the selected component dialog box, select an element after ( click on the ” OK ” after ) , the device will be displayed in the list of elements , later to use this element, just in the component list can be.

5 . Toolbars direction (Orientation Toolbar):

Rotate :

The rotation angle can be an integer multiple of 90 .


Flip Horizontal and vertical flip finish . Use: Right-click the component , and then click ( left-click ) the corresponding rotation icon.

6 . Simulation Toolbar

1 * Run

2 * single-step operation

3 * Pause

4 * Stop

AVR microcontroller simulation example:

We want design an AVR driver for a LCD1602 and monitor it with an oscilloscope data lines. Parts of file formats generated by the compiler are different, such as ICC is COF, IAR is D90, GCC is COF, ELF. Proteus supports files COF, D90, HEX , etc.

Run Proteus Professional , the following window appears :



1, Add the components, in this case ATMEGA16, LM016L (LCD1602), after we’ ll add the oscilloscope.Click the “P” button to select Component dialog box appears


KEYWORDS of the dialog box , enter the ATMEGA16, get the following results :


Click OK, and close the dialog box , then the components listed in the list ATMEGA16, also find LM016L. The end result :

2 , place components: the component list, select Left ATMEGA16, in the schematic editor window, click the left button , so ATMEGA16 is placed in the Schematic Editor window . Similarly placed LM016L.


Add “ground” : Left Select model selection toolbar icon appears:

Left selection GROUND, and in the schematic editor window, left-click , so that the “ground” was placed into the Schematic Editor window .

Add Oscilloscope: Left Select model selection toolbar icon appears:

Left selection OSCILLOSCOPE, and in the schematic editor window left click , so that the oscilloscope is placed to the Schematic Editor window.

place components paying attention to place them inside the blue box of workarea.

3 . Connection. AVR, LCD ‘s VSS, VDD, VEE don’t need connections , the default VSS = 0V, VDD = 5V, VEE =-5V, GND = 0V

4 . Add a simulation file. Right click before on ATMEGA16 then select Edit Properties

in the Program File , click the File Browser dialog box, locate lcd_C.hex file, click OK to finish adding files.Set Clock Frequency at 8MHz, click OK to exit.

5 . Simulation

Click Start simulation :

Description: red for high, blue represents low, gray represents uncertainty level (floating). Running in the Debug menu, you can view the AVR related resources.

6 , the source code debugging

Proteus supports COF file debugging. Be sure to create this file in your compiler options.Complete the schematic drawing and add debug files (COF file ) , click:

the AVR Source Code window appears , if the state does not appear in the debugger , go to Debug menu to find .


Let’s say something about these icons

1 * continuous operation , it will exit the single-step debug state , and close the AVR Source Code window

2 * single-step operation , skip directly encountered Functions

3 * single-step operation , will enter its internal encountered Functions

4 * out of the current function , when using 3 * into the internal function , use it immediately on exiting the function returns a function , it should be seen in conjunction with the 3 *

5 * run to the line where the mouse

6 * Add or remove a breakpoint , the breakpoint is set using the program will stop at the breakpoint.

Getting Started with EDWinXP

In this article we ‘ll study a Series Voltage Regulator schematic circuit using the SPICE simulation software EDWinXP. After the installation, run the program

Let’s create a new project selecting Edit Page from MAINPAGE

It opens a new page


TINA Design Suite Video tutorials

Introductio to TINA Design Suite
Comparison of simulation and real time measurements
Real time transient recording and comparison with simulation
RC transient and AC analysys
Fourier analysis
Active band pass filter
How to make subcircuits from schematics
Test a logic gate in interactive mode
Bus example
Pic flasher circuit
VHDL circuits
Create a simple PCB
Importing PSpice Netlists into TINA

Importing PSpice models into TINA

In this article we ‘ll see how to import PSpice libraries into TINA. Let’s start from the schematic of a basic three stage amplifier


right click on one transistor of differential couple, and select “Properties…”

the Properties window appears, click the ellipsis button and the Catalog Editor window pops up

the table view that appears is because the 2N5104 PNP transistor is a component of a *.cat library, a TINA’s CATalog files that contains the built-in TINA components and the built-in semiconductor catalogs

first of all, we want to show how to replace the built-in 2N5101 with the following PSpice model of the same PNP transistor and add it to an existing .lib library. It could be a different model of PNP transistor but is not important for the purpose of our example


Open the library Manager tool of TINA suite

and select, for example, the s_AFBJT.lib library file

ViaDesigner Video Tutorials

Creating Tutorial Designs within ViaDesigner
Creating Simulation Models with the Datasheet Curve Tracer in ViaDesigner
“Do The Harlem Shake” Circuit to Detect Low Frequencies Audio Signals
Creating a VHDL model in ViaDesigner
Importing & Processing Oscilloscope Data in ViaDesigner Simulations