The Engineering Projects

JFET Applications | Constant Current Source | Chopper

Hi Pupils, Welcome to another Experiment of Proteus at The Engineering Projects. Previously, we saw what are the Junction Field Effect Transistors. Today we'll learn about some of the applications of Junction Field Effect Transistors.

Just before the Experiment, it is useful to revise that: Transistors are three terminal, unipolar Devices. The terminals of Junction Field Effect Transistor are named as :

• Drain
• Source
• Gate

The Gate Terminal is common to both Source and Drain. Prior to start, let's clear some Concepts about Junction Field Effect Transistor.

Resistor

Resistor is an electrical device. we define the resistors as:

"A Resister is a two terminal Passive electrical device that shows the electrical resistance and is useful in almost every Circuit.

Resistors can be used to reduce or control the flow of current , terminate transition lines and such other functions.

Pinch off voltage

The basic Definition of Pinch off voltage is:

"The voltage applied between the Drain and the source at which the current maximum current flows through the circuit provided the Gate voltage is zero is called the Pinch off voltage."

when the value of voltages is less than the pinch off region, the voltage enters to another region called ohmic region of JFET and the transistor acts as a resistor in this region.

Controlling Voltage

The Controlling Voltage of Junction field effect transistor is defined as: "The controlling Voltage is the voltage of transistors from gate to source.  To set its value, the Voltage from gate to source is made negative and it is referred as Vgs." FET's are widely used in the worlds of electronics because of their size and the performance. We'll apply JFET's in the making of two of circuits:

1. Constant Current Source.
2. Chopper.

During the Implementation of the Circuits, we'll use N-type JFET because of the better flow of electron of this kind of JFET. In N-type JFET the majority charge carriers are electrons. I am going to explain it one after the other.

Constant Current Source

A Field Effect Transistor can be use as a constant current Source. That spell out that if JFET's are designed so, they can provide a constant current across the load resistor, no matter how much current is provided at its input. The ability is due to the near horizontal line in the drain characteristics of the JFET. Recall that resistor is a two terminal Device that reduces the current flow, divide voltage or adjust signal lines. But, carefully Controlled JFET can be used to overcome the resistance through the resistor that come in between the JFET and the Voltage source. In the circuit, when the Vgs is greater than the pinch off voltage. mathematically,

V-IR>|V|

Implementation in Proteus ISIS

To make the circuit for Constant current Source, we need the Components as:

Component Required:

1. Junction Field Effect Transistor
2. Resistor
3. Ground Terminal
4. Direct Current Power Supply
5. Connecting Wires

Procedure

• Fire up your Proteus Software.
• Choose the JFET and Resistor from the Pick library through the "P" button.
• Take the Ground Terminal from Terminals library from the left most tab.
• Take DC power source from the "Generator mode".
• To measure the Current we'll add a DC ammeter from the "Virtual Instrument Mode".

This is the step where the Circuit should be arranged so, to get the required output.

• Connect the Source with the Drain thorough a wire.
• Join the Ground Terminal with the wire that connects Source and Gate.
• Connect the Components on the Working area according to the diagram:

• Double Click the Battery and give it a value of 9 volts.
• Double click the voltmeter and change the display Range to milliamps.
• By the same token, Double tap the resistor and give it the value of 1k ohm.

NOTE: you can also use a variable resistor.

•  Record the values of the ammeter.
• At first observations, Change the value of resistor to 1kohm.
• Pop the play button.

The ammeter shows the value of the 0.40 miliamps.

• Take seven reading by changing the value of resistor and make a table.

  Resistance	Current
  1k ohm	0.40 *10-3
  2k ohm	0.40 *10-3
  3k ohm	0.40 *10-3
  4k ohm	0.40 *10-3
  5k ohm	0.40 *10-3
  6k ohm	0.40 *10-3
  7k ohm	0.40 *10-3

   

The same experiment can be done by varying the value of battery and recording the values.

Chopper

A Chopper is the application of Transistor that show us the output as the square wave. We define the Chopper as: "Chopper is an electronic circuit used to take the amplified Direct current by using some type of transistor or other device." One can use any kind of transistor  e.g Bipolar Junction Transistor tor make the Chopper circuit. But, Junction Field Effect Transistors are better for this purpose due to the field control of the JFETs. In Choppers, the FET act as a variable resistance.   Lets rush towards Proteus to apply the circuit.

Implementation of Choppers in Proteus ISIS

• Fire up your Proteus ISIS.

Material Required

1. Junction Field Effect Transistor
2. Resistor
3. Alternating current source
4. Ground
5. Oscilloscope

• Pick the Vsine , Resistor and JFET from the Pick library by the mean of "P" button.
• Take the Oscilloscope form "Virtual Instrument Mode" and fix it just above the Circuit.
• Connect Channel A just after the AC source and channel B with the Source.
• Put the Ground terminal below the circuit by choosing it from "Terminal".
• Change the value of resistance connected to AC as 100ohm.
• Change the value of resistance connected to Source as 200ohm.
• Give the frequency to 1000Hz and Amplitude of 12V to Vsine.
• Join the circuit according to the image given below:

Seems like our circuit is complete now.

• Press the Play button to simulate the graph.
• Set the Value of Channel A to 1V.
• Set the channel B to 20V.

The Output of the circuit is:   This Conversion is important in some Circuits. The output of the Chopper is in the form of square waves. Thus, today we learnt about the JFET along with the applications of JFET as Constant current and Chopper in detail and saw their Implementation in the Proteus.

Shunt Clippers and Dual Clippers in Proteus ISIS

Bonjour trainees!!! Welcome to the Engineering projects, We hope you are doing great. In our previous lecture, we discussed the first type of clippers in detail i.e. Series Clippers. Today, we are going to discuss the next two types of Clippers i.e. Shunt Clippers and Dual Clippers. Here are the types of Clippers from the last lecture:

So, today, we are going to cover the below concepts:

1. what is a Shunt Clipper?
2. Types of Shunt Clippers
3. Implementation of shunt Clippers in Proteus ISIS.
4. Dual Clippers basics.
5. Implementation of Dual Clippers in Proteus ISIS.

So, let's get started:

What is a Shunt Clipper?

• In Shunt Clippers(Parallel Clippers), the diode is connected in Shunt(Parallel) to the input signal source & the load resistance, as shown in the below figure:
  

As the diode is in parallel with the load & source, so during the positive half cycle, the diode will be in the forward-biased state(short circuit) and thus no current will flow to the load resistance. While during the negative half cycle, the diode will be in a reverse-biased state(open circuit) and the load resistance will get all the current flow.

Now, let's have a look at the types of Shunt Clipper:

Types of Shunt Clippers

Shunt clippers are Classified into four main types, named:

• Positive
• Positive with bias
• Negative
• Negative with bias

Let's implement these Clipper types in the Proteus:

Implementation of Shunt Clippers in Proteus

So, open your Proteus software and add these components:

Components Required

1. Vsine
2. Diode
3. Resistor
4. Ground terminal
5. Oscilloscope

• We can get the first three components from the "Pick library" by searching for the required component.
• We can get the Ground Terminal by left-clicking on the screen and then go to Place>Terminal>Ground.
• Get the Oscilloscope from the "Virtual Instrument" in the leftmost bar.

Now let's design the first type of Shunt Clipper:

Positive Shunt Clipper:

Now place the above components in the Proteus workspace and design the circuit, as shown in the below figure:

As you can see in the above figure, the diode is placed parallel to the load resistance. The arrowhead of the diode points opposite to the input source. As we discussed above, the load resistance will get voltage only if the diode is in a reverse-biased state. In the current arrangement, during the negative cycle of the AC signal, the diode will be reverse-biased, and the load will get complete power. The positive cycle of the input will be clipped off, as the diode will be in a forward-biased state, not allowing any current to flow through the load.

Change the values of components according to the below table:

Components	Value
Resistor R1	600 ohm
Resistor R2	500 ohm
Vsine	Amplitude =110V,Frequency= 1000Hz
Oscilloscope	Time= 0.2m-1,Voltage 20V

• Now run the simulation and you will definitely acquire the required output:

Positive with bias:

If you recall from our previous lecture on Series Clippers, we have added a battery in the bias clippers. Here, we are going to do the same, as shown in the below figure:

As we can see in the above figure, a battery of 5V is added in series with the diode. By adding the battery in the circuit of positive shunt clippers, we can easily control the amount of signal to be clipped. This arrangement is called Positive Shunt Clippers with bias or Biased Positive Shunt Clippers.

In the above circuit, we placed the battery just after the diode and the Positive Terminal of the battery connects with the diode's arrowhead and the negative terminal is connected to the Vsine source.

Here's the output of Positive Bias Shunt Clipper:

Negative Shunt Clippers:

In negative Shunt Clippers, the diode polarity is reversed i.e.the positive end of the diode is connected to the negative terminal of the battery and the negative end of the diode is connected to the positive terminal of the battery, as shown in the below figure:

In this arrangement, the diode is forward-biased during the negative half cycle, so no current will pass to the load. We can say, the negative cycle is clipped off. While in the positive cycle, the diode is reversed bias(open circuit) and thus current is flowing through the load resistor.

We will get the following waveform on the oscilloscope:

Biased Negative Shunt Clippers:

By now, you must have understood that an extra battery is added in series with the diode to create a Bias Clipper. As it's a negative bias, so the polarity of the battery is reversed i.e. the negative terminal of the battery is connected to the diode and the positive terminal of the battery is connected to the Vsine Source. The output is shown in the below figure:

So, that was all about the Shunt Clippers. Now let's have a look at the third tye of clippers i.e. Dual Clippers. Let's get started:

What is a Dual Clipper?

As the name depicts, the Dual Clipper is a combination of two types of Shunt Clippers i.e.

1. Biased Shunt Positive Clipper.
2. Biased Shunt Negative Clipper.

Now, let's move towards its simulation:

Dual Clipper Proteus Simulation

We have studied both Positive & Negative Bias Shunt Clippers in the previous section, so now we need to add both clippers in a single circuit, as shown in the below figure:

As you can see in the above figure, the circuit has four parallel branches, let's discuss them one by one:

• The First branch has an AC input source.
• The second branch has a Biased Shunt Positive Clipper i.e. Diode and a battery.
• The third branch has a Biased Shunt Negative Clipper i.e. Diode and a battery, but here the polarity is reversed.
• In the fourth branch, we have the load.
• Pop the Play button, and have a look at the output:

One can see that we got a square wave that conducts the current in both directions but in clipped form. We need Dual clippers in the place where we need to clip some part of both sides of the sinusoidal wave.

So, that's all for today. In this article, we discussed what are Shunt Clippers? what are their types? and How to simulate in Proteus? We also discussed Dual Clippers along with their implementation in Proteus ISIS. Take care!!!

Full Wave Rectification in Proteus

Hey buddies, hope you all are fine. In our previous tutorial, we studied Half Wave Rectification and have seen that it rectifies the half wave of the AC signal. Today, we are going to study Full Wave Rectification to rectify the complete AC source. We will design the simulation of the Full Wave Rectifier in Proteus software. So, let's get started:

What is Full Wave Rectification?

A comprehensive definition of full-wave rectification is:

• Full-wave rectification is a process to convert both cycles(positive & negative) of input(sinusoidal) wave to pulsating DC (Direct current).

We have studied in the previous lecture that Half Wave Rectifiers are used to convert only one cycle(either positive or negative) of an AC signal into a DC signal, thus dissipating the 50% energy of the overall signal. But in Full Wave Rectifiers, both cycles of the AC signal are converted into a single pulsating DC signal.

We used a single diode in our circuit to achieve half-wave rectification but for full-wave rectification, we need to create a bridge using 4 diodes. Here's the circuit diagram of Full Wave Rectification, designed in Proteus:

Why Full Wave Rectification?

Full Wave Rectification is always preferred over half wave rectification because of following factors:

• In half-wave rectification, half of the wave gets wasted as the diode suppresses the second half cycle. But if we add the diode bridge, we can easily get the complete signal i.e. both of its cycles.
• Full Wave Rectification gives higher output values with a low ripple factor.

Full Wave Rectifier Simulation in Proteus ISIS:

You can download the complete Proteus Simulation of Full Wave Rectifier, by clicking the below button:

Full Wave Rectification in Proteus

First of all, we have to pick the components from the Proteus Components Library. We are going to need these three basic components:

1. Full Wave rectification bridge
2. Resistor
3. Alternating voltage source

• Go to the pick library button and select these components, as shown in the below figure:
  

• So, design the circuit for full-wave rectification in Proteus, as shown in the below figure:

• Change the value of load resistance to 500 ohms.
• Set the Vsine Frequency to 1000Hz & amplitude to 120V.
  

Now we are going to place an oscilloscope to monitor the input & output signals. You will find the oscilloscope in the "Virtual Instruments" section on the left bar. So, our final circuit with an oscilloscope is shown in the below figure:

• The oscilloscope settings are shown in the below figure:
  

The output of oscilloscope is shown in the below:

As you can see in the above figure:

• The Yellow(A Terminal) wave shows the sinusoidal wave. Whereas, the blue wave (B terminal) shows a positive half-cycle and the magenta one (C terminal) shows a negative half-cycle. And the magic is, both the outputs are direct currents and are combined in a single direction at the load resistance.

Thus, today we studied another simple Proteus experiment that shows what is full wave rectification, how to make the simplest circuit that shows the best output of full wave rectification and why we need the full wave rectification circuit. Till the next tutorial, take care!!!

Common Collector BJT Amplifier in Proteus ISIS

Hi Mentees, Welcome to a new tutorial at The Engineering Projects. Today You will unearth about Common Collector bipolar Junction Transistor Amplifiers. Before this, we learnt about two types of Configurations of Transistors named Common Emitter BJT Amplifiers and Common Base BJT Amplifiers.

In this tutorial We'll discuss about:

1. Introduction of Common Collector BJT Amplifier.
2. Basic Concepts for the Common Collector BJT Amplifiers.
3. Implementation of Common Collector BJT Amplifiers in Proteus ISIS.
4. Characteristics and advantages of Common Collector BJT Amplifiers.

So that, you can get the best understanding about the topic and its practical implementation.

Introduction

1st  of all, We'll have a brief definition of the Common Collector Amplifier: " A type of Bipolar Junction Transistor Amplifier is called Common Collector BJT Amplifiers in which Collector is common to both Base, Base region is used for input and emitter is used to take the output of the Amplifier."  It is one of the Configuration of the Transistor and is used in many kinds of circuits due to its efficiency. Other two Configurations are;

1. Common Base BJT Amplifiers.
2. Common Emitter BJT Amplifiers.

All of them acquire their Own Construction, characteristics and advantages as we as disadvantages. Common Collectors are also called as Emitter follower Configuration as the emitter voltage follows the base voltage.

Basic Concepts:

It is Always useful to get core information about the circuit before its Implementation. Let's see what a Common Collector amplifiers is. Type of transistor: Recall that  the are two types of Transistors i.e, 1. NPN 2.PNP. the Transistor we are using NPN transistor for our Experiment because in this type, the electrons are majority carries that have more mobility than holes ( majority charge carriers in PNP transistors) therefore, we get quick and easy output due to best electron flow.   Current Gain: The current gain of this type of amplifier is also taken as the division of the Emitter current with the base current and mathematically it is stated as:

Current Gain = Emitter current/Base Current

? = I_E/I_B = ß + 1

Voltage Gain : Voltage Gain of Common Collector BJT Amplifier is considered to be the unity, i.e. 1 and is obtained by the formula given below: Voltage Gain=Vout/Vin where in Common Collector amplifier we give the input to Base and take the output from the emitter of the transistor. Emitter Current: in this Configuration the Emitter current is taken as the sum of base current and collector current. consequently, we say  Ie=Ib+Ic we can use this equation in others ways as,

Ib=Ie-Ic

Ic=Ie-Ib

we can also say that the collector current is approximately equal to Emitter current because base is very thin region and passes a minute amount of current through it.

Implementation of Common Collector BJT Amplifier in Proteus ISIS

At the instance, we will test the circuit given in the circuit diagram in Proteus. the material for the Circuit is given below. Material Required: 

1. Transistor (2N1711)
2. Capacitor
3. Resistor
4. Vsine
5. Oscilloscope
6. Ground

• Take 1st four components from the "Pick device" library presented at the left corner of the screen.
• Set them at the working area according to the circuit diagram.
• Add the ground terminal by left clicking the screen >Go to Place>Terminal>Ground and add the ground Terminal.

NOTE: You can also connect just one Ground terminal to the circuit if you connect the Circuit with a wire at the bottom. Now, the Circuit will look like this:

• Add the DC source from "Generation Mode" to just above the circuit.

Now, We need an output device to examine the output. Therefore, We'll use Oscilloscope. Choose it from "Virtual Instrument mode".

• Set the Oscilloscope just aside the circuit and Connect Channel A with input (Base) and the Channel B with the output ( Emitter).

Before Starting the simulation, I am going to change the values of the Components I used because the default values will not give us the required Output.

• we will use the 120V for the DC Power source.
• One can clearly examine that the Values of the Components are given according to the table given below:

Components	Values
Resistor R1	10ohm
Resistor R2	100ohm
Resistor R3	20ohm
Resistor R4	100kohm
VSine	Amplitude=220, Frequency=1000
Capacitor 1	50m
Capacitor 2	2m
Oscilloscope	Channel 5V, Channel B=5V, Time=0.2mS-1

 

• After setting the values  you can change the value of Oscilloscope to get the required output.

NOTE: The amplifiers are sensitive to the temperature and the type of transistor used, hence their must be the practice to get the best output.

Characteristics

• The input Resistance of Common Collector Amplifiers is high.
• The power gain of this kind of amplifiers is medium.
• It has low output resistance.
• It has non-inverting effect (opposite to other two Configuration that gives the inversion of the wave).
• It has zero voltage gain.

Advantages of Common Collector BJT Amplifiers

1. It is useful for the circuits where the high impedance is required.
2. It is mostly used as voltage buffers as the voltage gain is unity.
3. The Common Collector configuration is used in the Circuit where the engineers want the high current gain.
4. Due to its high current gain, it is applied in circuits to drive heavy loads.
5. We use it for voltage translation stage.

NOTE: Sometimes, It becomes the disadvantage of the Common Collector bipolar Junction Transistor Amplifier that they have no voltage Gain. Summary: Today, we ascertained the Basic Common Collector BJT Amplifiers, learnt some Concepts about it, saw the Implementation in Proteus ISIS, saw some characteristics and found the advantages of the Common Collector Configuration.

Common Emitter BJT Amplifier in Proteus

Hi Learners, I hope you are doing good. This lesson is about implementation of one of the types of  Amplifiers i.e, Common Emitter BJT Amplifier. But, prior to this, we'll revise some basic concepts so that it will be easy for you to understand the roots of the Experiment. We'll talk about:

1. What are Common Emitter Bi-Junction Transistors.
2. Concepts of Common Emitter Bi-Junction Transistors.
3. Implementation of Common Emitter BJT Amplifiers in Proteus ISIS.
4. Why we use Common Emitter BJT in Amplifiers.

What are Common Emitter Bi-Junction Transistors

There are three types of Configurations of a transistor named:

1. Common Emitter Configuration
2. Common Base Configuration
3. Common Collector Configuration

We chose the Common Emitter Configuration due to its suitability (You will learn the reason). We can Define Basic Common Emitter BJT Amplifier as: "A type of amplifier circuit made by a Bi-Polar junction Transistor that uses NPN BJT Transistor, inverts the voltage output wave at 180 degree and is the one from the three basic BJT amplifier Configuration." Recall that A Transistor is made by combining two diodes in required manner. Hence, It there are two types of Transistors:

1. NPN configuration.
2. PNP Configuration.

Here N is the symbol for Negative doping and P is the symbol for positive doping.

Concepts of Common Emitter Bi-Junction Transistors

At this instance We'll look at some basic concepts, on the basis of which we chose these Components along with the values of Components  of amplifier. Current gain: In BJT Amplifiers, current gain is the ratio of change in collector current to the change in the current of base.

mathematically,           Current Gain= Change in collector current/Change in Base Current

ß=?Ic/?Ib

At the same token, Voltage Gain: The Voltage Gain of an amplifier is the product two Quantities. One is the ratio of output resistance of the collector to the input resistor of the base, and the other is the current gain.

Voltage Gain=ß(Rc/Rb)

During the Practical work we take  AC output voltage from collector with respect to emitter and the Output of Amplifier is taken from Collector. On the other hand, the input is given to the base terminal. It is obvious to notice that the emitter is Common to Base and Collector. It consist of Voltage divider biasing, hence one of the basic part of circuit is consist of two resistors so that their mid-point is used for supply Base Bias voltage. One more importance point to remember is gain is different from one transistor to the other. Biasing: Biasing is a technique  to add the Battery in a circuit. It is important in Electronic devices because it establishes the correct operating point of the Transistor amplifier when it is ready to receive the signal from input and hence the plays an important role in reducing the distortion in the output. If we look at the characteristics then we come to know that Common Emitter BJT Amplifiers has high voltage gain, the current gain is medium and the circuit has a high power gain.

Implementation of Common Emitter BJT Amplifiers in Proteus ISIS

For the practical verification of the circuit It is always Advisable to Perform it at any simulation software. Hence open Your Proteus ISIS. Components Required:

1. NPN transistor (2N171) .
2. Vsine
3. Capacitor
4. Resistor
5. DC Power source
6. ground Terminal
7. Oscilloscope

Procedure:

• Choose 1st four Components from the Pick Library "P" one by one by writing their name in it.
• Collect the DC power supply from "Generator mood" present on the left most tab.
• To get the Ground terminal, left Click on the working screen and go to Place>Terminal>Ground and fix it on the screen.
• Oscilloscope is present in the "Virtual Instrument Mood" on the same tab.
• Once you have chosen all the  required Device  then set them one by one on the Working area according to the Picture given below and connect them with the help of wires.

• At the Instance we will change the values of some devices So I have made a table for this:

• Components	Values
  Resistor R1	60ohm
  Resistor R2	500ohm
  Resistor R3	1000ohm
  Resistor R4	2000ohm
  Resistor R5	100ohm
  Oscilloscope	A=20V, B=2V
  Vsine	Frequency=1000Hz, Amplitude=110V
  DC source	10V

After substituting the value we get the prepared circuit for the amplifier as: It seems that all the things are ready. Once you play the simulation then you can change its values and You will acquire the following output.

• Select the Current probe from the left most bar and connect them in the circuit one with the Base wire and the other with the collector.

One can find the current gain by simply putting the values in the formulas given in the concepts portion.

here,

Current gain=6.2*10^-12/6.1

                             =1.01*10^-9

as it is a ratio, hence has no unit.

At the same token,

Voltage gain=1.01*10^-9*(500/2000)

 =2.5*10^-10

NOTE: The Gain is vary from transistor to transistor and the temperature is also an important feature. Therefore, the gain is always unpredictable.

•  We got the required output in the Proteus ISIS as required.

let's find out why we used this for our experiment.

Why we use BJT in Amplifiers

Common Emitter BJT Amplifiers are important in the World of Electronics. One can get the idea of their influence by the following points:

1. These Amplifiers are used in low frequency voltage amplifier.
2. The are useful because of their high power gain with medium voltage and current gain hence they are cheap.
3. The output impedance is high.
4. It has inverting effect so can be used in the different appliances for different purposes.

In today's tutorial, We learnt what is Common Emitter BJT amplifiers, some basic concepts along with the simulation in the Proteus ISIS. We also saw why these Amplifiers are used in the real life. The circuit and the output may vary for other circuits but don't worry about that because it is a very sensitive circuit.

Common Base BJT Amplifier in Proteus

Hi mentees, Welcome to The Engineering Projects. If you are seeking for the Practical Implementation of Common Base bipolar Junction Transistor amplifier then you clicked at the best website because we'll cover the basic concepts and the procedure step by step. So, Lets start the learning.

What is Common Base BJT Amplifier?

The precise definition of the Common Base BJT Amplifier is: "The type of Bipolar Junction Transistor Amplifiers in which Base is Common to both emitter and Collector and Current gain is taken from the Base is called Common Base bipolar Junction Transistor Amplifiers." Recall that a transistor has three regions i.e, Base, Collector and Emitter. Hence we design our Circuit in such a way that we get the output of current from the base and get the best current gain.

Basic Concepts:

Some Important Concepts should be kept in mind so that it will become easy and interesting to Design the Circuit. Current gain: " The Current gain of Common base Amplifier is equal to the ratio of Current in the Collector to the Current in the Base provided by the constant voltage of base to collector." Mathematically,

Current gain=Collector Current/Base Current

ß=Ic/Ib

Voltage Gain: "The Voltage gain of the Common Base amplifier is obtain when we divide the Voltage of Collector to the voltage of emitter." mathematically,

Voltage Gain=Voltage of Collector/Voltage of Emitter

Av=Vc/Ve

Type of Transistor: In the Common Base amplifiers, we use the NPN transistor because in this way we get the require output more easily. In NPN transistors, majority is the electrons. The mobility of electrons is better than holes (in PNP Transistors) so they are faster. Biasing: Biasing is a technique  to add the Battery in a circuit. It is important in Electronic devices because it establishes the correct operating point of the Transistor amplifier when it is ready to receive the signal from input and hence the plays an important role in reducing the distortion in the output. Common base MUST  correctly Biased so that the base-emitter junction will remain forward Bias. Now, Let's move towards the practical implementation.

 Implementing Common Base BJT Amplifier in Proteus ISIS

To Perform the experiment. we need the Proteus ISIS then follow the steps: Material Require:

1. Transistor (2N1711)
2. Capacitor
3. Alternating Current Source (Vsine)
4. Resistor
5. Oscilloscope
6. Ground.

• Open Your Proteus software in the PC.
• Seek the Pick Library "P" button and write the name of 1st four Components one by one and select them.
• Place the current components on the working area.
• Acquire the Oscilloscope from the "Virtual Instruments mode" from the left most area and fix it just above the circuit.
• You can obtain the Ground Terminal by left click on the screen>Place>Terminal>Ground or just search it in the "Terminal mode".
• Connect all the Components through wires. The circuit looks like the image given below:

• At this instance , Change the name and values of resistors one by one by double clicking them. In this way, the circuit will work Perfectly.

• I labelled all the Resistors with different names and changed the values according to the need.
• At the same token, the name of Capacitor, battery cells and their values are also changed according to the table given below:

Components	Values
Resistor R1	400ohm
Resistor R2	30ohm
Resistor R3	100ohm
Resistor R4	200ohm
BAT	50
BAT 1	200
CIN	2mF
COUT	60uF
Oscilloscope	Channel A=20V, Channel B=20V, time=0.5m-1
VSine	Amplitude 220V, Frequency=1000

• Set all the values according to table.
• Once the values are selected (except Oscilloscope) just Pop the Play button.
• You can see an Oscilloscope screen showing the waves.
• Turn of the Channel C,D to avoid distraction.
• Set the values of Oscilloscope by matching with the table.
•  You will get the output just like shown in the following image:

The Yellow wave (channel A) indicates the input wave were as the Blue Wave (Channel B) indicates the output ( Amplified) wave. Hence by If we choose the Components and there value carefully, we get the best output. Lets Calculate the Current gain then Voltage Gain. I am using the previously Described precepts to calculate the Quantities:

• Connect the DC Ammeter from the "Generation Mode" and Connect one with the Base of transistor and one with the Collector.
• When we play the Simulation then we get the following Output:

Applying the values into the formula we get,

ß        =-1.43/-0.07

 =20.4

As it's a ratio so it doesn't have any unit. Moving towards the Voltage Gain,

• Take the "DC Voltmeter" from the same Portion and connect one Voltmeter with CIN capacitor and one with the COUT Capacitor. Note than the Voltmeter is always Connected in parallel to the required Components.

At the moment, When we start the simulation, we get the following output: Applying these Values for Av,

Av=53.1/3.75

    =14.16

So that the required Quantities are obtained.

Characteristics of Common Base BJT Amplifiers:

• It has High Voltage Gain.
• The Current Gain of Common Base BJT Amplifiers is Medium.
• We get High power Gain in this type of Amplifier.
• Common Base Amplifier does not have any reversal effect between input and output waves.
• The Input and Output resistance of the Common Base Amplifier is Medium.

Advantages:

• We Get the inverted output wave that may be useful in many electronic devices.
• The Input Impedance is Low.
• It is useful due to its high power gain.
• The output Impedance is High for Common Base Bipolar Junction Transistor Amplifiers.
• The Output Impedance is high.
• When we need  Impedance matching then CB Amplifiers are useful because we can control the input Impedance.
• It Provides the constant Current Gain therefore can be used as buffer amplifiers.

Thus Today we Learnt about the Common Base Bipolar Junction Transistor Amplifiers, cleared Some Basic Concepts about them, Implement the Amplifiers in Proteus ISIS and read about the characteristics and advantages of the Common Base Bipolar Junction Transistors Amplifiers.

Series Clippers and its types in Proteus

Hello friends, I hope you all are having fun. In today's tutorial, we will have a look at Series Clippers & their types in detail, we will also implement the simulations of Series Clippers in Proteus software. In the next article, we will discuss the next two types of Clippers i.e. Shunt Clippers & Dual Clippers. Today, We are going to learn:

1. What is a Clipper?
2. What are the types of Clippers?
3. Series Clippers Simulations in Proteus.

So, let's get started:

What is a Clipper???

• Clipper (also known as Limiter) is an electronic circuit, which clips or limits the amplitude(positive, negative or both) of an AC source wave.
• Diodes are normally used for designing Clippers and such circuits are normally referred as Diode Clipping Circuits (Diode Limiting Circuits).
• Here's an example of a Diode Clipping Circuit, where we are clipping the positive amplitude of the AC pulse:

• As you can see in the above figure, we are clipping the positive side but if we want to clip the negative side, we just need to reverse the diode polarity.
• Clippers are normally used for protection purposes i.e. if there are some voltage spikes then clip it to secure home appliances.
• Half wave Rectifier is also a type of clipper as it clips one side of the AC pulse to 0V.

Now, let's have a look at different types of clippers:

Types of Clippers

In the previous section, we have had a complete understanding of what is clipper. Now let's have a look at three different types of Clippers:

• Series Clippers.
  • Positive.
  • Positive with bias.
  • Negative.
  • Negative with bias.
• Shunt Clippers.
  • Positive.
  • Positive with bias.
  • Negative.
  • Negative with bias.
• Dual (Combination) Clippers.

As today's topic is about Series Clippers, so let's implement them in Proteus ISIS:

Series Clippers Simulation in Proteus

• First of all, we need to open the Proteus ISIS software to design our circuit.
  
• Select the following components from the "Pick Components" section:
  
  • Diode
  • Resistor
  • Vsine source
  • Battery
• So, first of all, let's place our AC source Vsine and GND in the proteus workspace.
• Double-click on the Vsine source and change the value of amplitude and frequency to 11V and 1000Hz respectively.

Our power source is ready, now let's design different types of Series Clippers in proteus:

1. Positive Series Clippers in Proteus ISIS

• In Positive Series Clipper, the positive half cycle of the wave is clipped(removed).
• In the positive clipper circuit, the arrowhead of the diode points towards the input source.
• So, let's design the circuit as shown in the below figure:
  

• As we can see in the above figure, diode D is connected in series with the load resistor and is pointing towards the AC source.
  
• Double-click at the resistor and change its value from 10k ohm to 500 ohms.
• We'll also add the DC voltmeter to show the difference between biased and unbiased circuit
• We've connected terminal A of the oscilloscope with the AC Source(Vsine) and terminal B is placed after the diode.
• This is the time to pop the play button and set values of the oscilloscope according to the below table:

Components	Values
Channel A	20V
Channel B	20V
Time	0.2ms-1

• If everything goes fine, we will get the required output as shown in the figure:

• In the above figure, the Yellow curve is showing the input voltage, while the blue line is the output voltage(after the diode) received by the load resistor.
• We can clearly see that the positive side of the AC source waveform is now clipped and that's why it's called Positive Series Clipper.
  

2. Positive with Negative Bias Series Clipper

The Positive Series Clipper removes the positive side of the curve completely but what if we want to clip only 25% of the positive side? In that case, we use positive with Negative Bias Series Clipper. It's circuit is shown in the below figure:

As we can see in the above figure, we have added an extra element called Battery.The rest of the circuit is same as that of the Positive Series Clipper i.e. the diode is pointing towards the current source and is in series with the resistor.

The volt meter is giving us -5V, where the 5V is coming from the added battery and the negative sign shows that the circuit is negative bias.

• The output for the circuit on the oscilloscope is shown below:

As you can see in the above figure, the output curve is slightly clipped at the top. If we reduce the battery voltage, the clipping of the curve increase and at 0V the complete positive part will be clipped out(same as Positive Series Clipper).

If you want a clipper with a positive bias, simply change the direction of the battery. Connect the negative terminal of the battery with the negative side of the diode. It's a task, post your results in the comments.

3. Negative Series Clipper in Proteus

• In a Negative Series Clipper, the negative half cycle of the wave is clipped(removed).
• In negative clipper circuits, the arrowhead of the diode points towards the load resistor.
• Here's the circuit diagram of the Negative Series Clipper:
  

• The circuit is the same as that of the Positive Series Clipper with a slight difference in the direction of the diode.
  
• The output of the oscilloscope for the series circuit of negative clippers shows us that the negative side of the wave is clipped:

4. Negative with negative bias Series Clippers

As we discussed, the whole negative part of the signal gets clipped in the Negative Series Clipper. So, in order to clip a certain amount of negative side, we need to add a new battery source and this model is called Negative with Negative Bias Series Clipper. It's circuit diagram is shown in the below figure:

As we can see in the above figure, the diode is pointing towards the load resistor. We have connected the negative terminal of the battery with the positive side of the diode. Here are the results from the oscilloscope:

So, that was all for today. In this article, we studied the series clipper and its types, along with their simulations in Proteus software. I hope you have enjoyed today's lecture. Let me know your feedback/queries in the comments. Have fun!!!

Simplest Half Wave Rectification in Proteus

Hello friends, I hope you all are doing great. In today's tutorial, I will show you how to perform Simplest Half Wave Rectification in Proteus.  In this tutorial, we will design a simple Proteus simulation, where we will use a diode for half-wave rectification.

Before designing the Proteus simulation, we will first have a theoretical overview of Half Wave Rectification as it's always the best approach to read theory before practical (Proteus Simulation). So, let's get started:

What is Rectification ???

• Rectification is an electrical process, used to convert Alternating(AC) Voltage into Direct(DC) Voltage using a circuit called rectifier.
• The Rectification process is always carried out using diodes, as we know diodes allow the current to flow in one direction only, thus they can easily block the opposite flow of alternating current.
• Based on DC output, rectification is divided into two types i.e.
  • Half-wave rectification. (needs single diode)
  • Full-wave Rectification. (needs multiple diodes)
• Now, let's have a look at, what's the difference between these two types of rectification processes:

Half wave Rectification

• In Half Wave Rectification, half wave of Alternating(AC) Voltage gets converted into Direct(DC) Voltage, while the other half gets blocked.
• A single diode is used for Half Wave Rectification, as shown in the below figure:

• We can allow either pulse(positive or negative) to pass or block and it depends on the diode's direction.
• In the above figure, we are allowing positive AC pulses to pass, while blocking the negative AC pulses.
• If we reverse the direction of the diode, it will block positive pulses & will allow negative ones.

Full Wave Rectification

• In Full Wave Rectification, a complete alternating(AC) pulse(both positive & negative) gets converted into Direct(DC) voltage.
• As you can see in the above figure, we are now utilizing both cycles of AC current and converting them into DC current.
• Hence, the full wave is more efficient than a half wave, as we have seen half wave simply drops half of the pulse.

As today's topic is about Half Wave Rectification, so we won't discuss it in detail but I hope, now you must have understood the difference between full wave & half wave. Let's design half wave rectifier in Proteus:

Half Wave Rectification in Proteus ISIS

• Proteus is one of the best software for simulating electrical/electronic circuits.
• Basically, we have to design a really simple circuit, as shown in the below figure:

• In order to design this half-wave rectifier, we will need these three components:
  • Sine Wave Generator.
  • Diode.
  • Resistor.
• So, click on the “pick” button and select these components from Proteus Library, as shown in the below figure:

• Now, let's design our circuit, so drag & drop these components one by one in the word space.
• Set the resistor's value to 500 ohms.
• Connect a ground terminal as we are using Vsine i.e. the alternating current source. You will find the GND component in the Terminal area from the left menu.
• Now let's connect the wires, as shown n below figure:

• Once we have completed the basic circuit, we’ll now analyze our output on the Oscilloscope.
• You will find it in the left menu under "Virtual Instruments".
• The Oscilloscope has four terminals named A, B, C, D. We’ll connect Terminal A before Diode and Terminal B after the diode, to analyze both Input and output at the same time.

• Double Click on the alternate current source to set the values.
• Here, I am using an amplitude of 110 ms^-1 and a frequency of 1000 Hz.

 

• I have normalized the oscilloscope axes for better examination of the pulses, here are my settings:

• Now run your Proteus simulation, and if everything goes fine, you will get results, as shown in the below figure:

HWR output through Analog Graph:

In the previous section, we have analyzed the curve with Oscilloscope. Now, we are going to use another awesome feature of Proteus i.e.e Analog Graph. We will plot our input/ output curves of Half wave rectifier on the analog graph in Proteus.

• First of all, remove the oscilloscope from the circuit.
  
• Select the "Current Source" and place one probe before the diode and one after it, to get both input and output at the same time.

• For the output, take the analog option from the graph terminal. Click on the screen where you want the graph. You can make the size of the graph according to your choice.
• So now you have a blank graph screen. You have to set the parameters, add the trace and then simulate it.
• So, let’s do it. Left-click on the graph screen will show you this dialogue box. Choose add trace.
• This will show you the screen where you can add the traces. Once you have added the traces one by one by clicking the required prob, we can proceed.
• This is the time when you have to edit the graph to show right output. Right click again on the graph screen will let you to see the dialogue box again. This time, you have to choose “Edit Graph”. Choose the value according to need. I am choosing "3m"
• .So, you have set all the required thing. This is the time to stimulate your graph and see the required result.

• This is the required result. We give the Input as alternating current, but in the output we got pulsating direct current that flow in one direction.
• We can maximize the result by right click and choosing “Maximize”.
• The green one is the input and the output that is in red is the output i.e.  direct current.

So, that was all. This was the tutorial in which we found what is rectification, what is the use of diode in the rectification, how can we use oscilloscope as well as analogue graph to see the result of rectification. For more tutorials and learning stay tuned with us.

Voltmeter & Ammeter in Proteus ISIS

Hello friends, I hope you all are doing great. In today's tutorial, we will have a look at How to use Voltmeter & Ammeter in Proteus ISIS. It's our 4th tutorial in Proteus series. While designing an electronics project, voltage & current measurements are essential debugging features, as they help in understanding circuit behavior. Proteus has builtin instruments for voltage & current measurement. We have have their probes and today we will discuss them in detail. First have a look at Voltmeter in Proteus ISIS:

How to use Voltmeter in Proteus ISIS

• DC Voltmeter is used to measure the voltage difference across any DC component.
• In order to use DC Voltmeter, we need to click on Virtual Instruments Mode, as shown in the figure.
• In Instruments list, we have DC voltmeter, so click it and place it in your Proteus workspace.
• I am going to use the same circuit, which we have designed in first lecture, shown in below figure:
• As you can see in the figure, I have placed two voltmeters, one at the input and second at the last LED.
• Because of 100kohm resistance, there's a slight drop in the voltage at last two LEDs.
• Moreover, Voltmeters are placed in parallel to these component.

• We can also use Voltage Probe to measure voltage at any point in the electronic circuit.
• So, click on Voltage Probe in the left toolbar and connect it to any point in your circuit and its voltage will be displayed.
• I have placed two Voltage probes on my circuit, as shown in below figure.
• Voltage Probe provides value up to five decimal points, while DC Voltmeter provides value up to 2 decimal points.

• Voltage probes are quite helpful as they are small in size and easy to place in the circuit.

So, that was all about Voltmeter in Proteus. Now, let's have a look at How to use Ammeter in Proteus ISIS:

How to use Ammeter in Proteus ISIS

• DC Ammeter is used to measure the current passing through any DC component.
• We need to click on Virtual Instruments Mode and then click on DC Ammeter.
• Place this Ammeter in series, as shown in below figure:

• We aren't getting any value on our Ammeter as these LEDs are not drawing much current.
• But, you can see we have placed the Ammeter in series, we will use it a lot in coming projects.

So, that was all about How to use Voltmeter & Ammeter in Proteus. I hope you have enjoyed today's tutorial. Till next tutorial, take care & have fun !!! :)

How to Increase Workspace in Proteus

Hello friends, hope you all are fine and having fun with your lives. Today's post is about How to increase Workspace in Proteus. It's our 3rd tutorial in Proteus series. Its quite a simple tutorial and along with this trick, I will also share few commonly used features or Proteus. Once, I was working on a simulation project in which I have to design a complete load management system in Proteus and it was quite messy as I have to include a lot of components and the area of Proteus got quite small for that and then I encountered this problem i.e. where to place the components.

You have seen in Proteus software that there's a blue rectangle which is considered as the workspace in Proteus. This area is constant and doesn't increase or decrease on its own. So if we are dealing with some messy circuit design then we have to increase this area, which we are going to discuss today. If you have downloaded my Arduino Library for Proteus, then you must have seen that the size of Arduino Mega 2560 is quite big and when I design Proteus simulations in which I need to use Arduino Mega, I have to increase the Proteus workspace to embedded all the other components. So, let's get started with how to increase Workspace in Proteus:

How to Increase Workspace in Proteus ???

• First of all, if you are working on some project in Proteus then simply don't increase the area because when you increase the area then components get too small and its quite difficult to arrange or connect them with each other.

• So, my suggestion is to keep using the default size, unless your circuit got messy and you actually need more space.
• Let's open Proteus software and place few components in it, as an example I am just placing PIC Microcontrollers to cover the available space, as shown in below figure:

• You can see in above figure, I have randomly placed 8 PIC Microcontrollers, just to fill the space.
• Now suppose I want to add four more Microcontrollers in this Proteus file, there's no place to add them.
• Now in order to add more components, we need to increase the size of available workspace in Proteus.
• In order to do so, click on Systems in above menu bar and then click on Set Sheet Sizes as shown in below figure:

• Now when you click it, a new pop up window will open up, as shown in the figure on right side.
• You can see in the figure, there are six sizes available for the user to select.
• First five are fixed sizes while the sixth one is user defined and you can set it to any size you want.
• The default size of workspace in Proteus is A4, which is the first option i.e. 10inch by 7 inch.
• So, now let's change this selection and I am selecting the fifth option so now the size is 15inch by 10 inch, as shown in below figure:

• Now its quite obvious from the above figure that the area has increased.
• We have the same 8 PIC Microcontrollers but now we have more free space.

Right Click to Delete Component

• Proteus has a quick way to delete any component or wire.
• You need to right click on your component/wire for 2 times and it will be removed/deleted from the workspace.
• It's quite helpful, especially in designing complex simulations.

Default Terminal in Proteus

• Let's discuss Default Terminal as well, which is used to keep the schematic organized & clear.
• We can get them by clicking on Terminals Mode first and then click on Default, as shown in figure on right side.
• In our previous lecture, we have designed a simple LED circuit, so let's make small changes in it, as shown in below figure:

• You can see in above figure that I have deleted the wires and placed these default terminals on both sides.
• In order to delete these wires, I have simply double right clicked on each wire and placed these terminals.
• Now, double click on each terminal and provide it a name, as shown in below figure:

• As you can see in above figure, top two Terminals are named as Terminal1 and below two terminals are named as Terminal2.
• So, although these terminals are not connected together but Proteus considers "Terminals with same name" as connected.
• If we run our simulation now, we will get the similar results, as shown in below figure:

• These default Terminals are too helpful, as in complex projects, adding too much wires make the simulation quite messy. ( We will use them in coming lectures )

So, that's how you can quite easily increase workspace in Proteus ISIS. That's all for today, it was quite easy tutorial but still if you are having any problems, then ask in comments and I will resolve them. Till next tutorial, take care !!! :)