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Types of diode

The semiconductor diode is a combination of two crystalline semiconductor materials, which designed the two materials know as p-type and n-type. So first let we understand what is n-type and what is p-type of materials

The n-type semiconductor has a larger electron concentration. This is done by introducing a donor as impurities. Here the n-type refers to the negative charge of the electron.

While in p-type of the semiconductor has larger hole concertation, here p-type refers as to the positive charge of the hole.

There are several types of diodes are available for use in electronics design namely a Gunn diode, Laser diode, LED, backward diode, BARITT diode, a PIN diode, PN junction diode, Tunnel diode, Schottky diode, Varactor diode, and Zener diode. Here this article gives the information about what is a diode, what is a Zener diode, different types of Zener diode, application, advantages etc.

The various types of diodes are as follows:

Varactor diode symbol

The symbol of the varactor diode is shown in the figure is given below. The varactor diode symbol consists of with capacitor symbol at the one end of the diode that represents the variable capacitor type characteristics of the varactor diodes to shown in figure.

In general, it looks like or similar to that a normal PN junction diode in which one terminal is termed as the cathode and the other terminal is termed as an anode. Here the varactor diode consists of two lines at one end cathode end of normal diode that indicates the capacitor symbol. The one end of a symbol consists of the diode and their other end has two parallel lines.

Varactor Diode Symbol

Characteristics of varactor diode

The below graph illustrates the relation between the magnitude of reverse bias voltage p-type and n-type layers of a varactor diode, and the magnitude of junction capacitance. They are voltage controlled capacitor and sometimes known as varicap diodes although the word varactor is widely used.

Variable capacitance effect is shown by a normal diode, but the varactor diode is preferred for providing required capacitance changes. The diodes are uniquely optimized and also manufactured such that they enable high range changes in the capacitance device. A varactor diode is categorized based on the properties of a diode junction.

The characteristics of the varactor diode have the following:

These diodes are significantly generated less noise compared to other diodes
The cost of these diodes is available at lower or more reliable also
These diodes are very small in size and very lightweight compared to other diodes
There is no use when it is operated in forwarding bias
In reverse bias mode, this diode enhanced the capacitance as shown in the graph below

Characteristics of a varactor diode

tunnel diode symbol

The tunnel diode is a highly doped semiconductor device, that is is highly conductive, heavily doped PN junction diode in which the current induces because of the tunneling. The symbol of a tunnel diode is shown in the figure given below. The n-type material emits the electrons and is named as the cathode while P-type material act as the electrons and hence it called as the anode.

tunnel diode symbol

Characteristics of tunnel diode

Forward bias condition:

Under the forward bias condition, the immediate conduction occurs in the diode because of heavily doped conduction happen in the diode. The current in the diode reached the maximum current that diode reached a maximum value of Ip and when the voltage applied is Vp across it. The current value is decreased when more amount of voltage is applied. And it current keep decreasing unit it reaches a minimum value. This minimum value of current is called as the valley current Iv. The tunnel diode and normal PN junction diode characteristics are different from each other.

Characteristics of the tunnel diode

Reverse bias condition:

Under the reverse bias condition, the tunnel diode act as a back diode or backward diode. In reverse bias condition, the empty state on the n side aligned with the filled state on the p side. The electron will tunnel through a potential barrier. Because of its high doping concentration tunnel diode acts as an excellent conductor.

The graph above shows that A to point of B the value of current decreases with the increases in voltage. So from figure A to B, the graph shows the negative resistance region of the tunnel diode, This region shows the most important property of the diode. Here in this region shown in, the tunnel diode produces the power instead of absorbing it.

Advantages and disadvantages of Tunnel diode

One of the main reason for the early success of the tunnel diode was its high speed of operation and the high frequencies it could handle. Here this post gives information about the advantages and disadvantages of the Tunnel diode to know more detailed about it.

Advantages of tunnel diode:

Low cost
Low noise
High speed
Fabrication is also very simple
Fast response
Moderate in operation
Low power
Longevity
Ease of operation
Environmental immunity
Insensitive to nuclear radiation

Disadvantages of tunnel diode:

The voltage range, which can be operated properly in around 1 volt or below
Being two terminal device, it provides no isolation between output and input circuit
The power output levels of tunnel diode are restricted to only a few milliwatts because the applied DC potential must be less than bandgap potential of the diode

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Advantages and disadvantages of varactor diode

The diode whose internal capacitance varies with the variation of reverse voltage such type of diode is known as the varactor diode. The varactor diode always works in reverse bias and it is voltage dependent semiconductor device. It is used in storing the charge. Here this article gives information about the advantages and disadvantages of varactor diode to know more detailed about it.

Advantages of varactor diode:

It generates less noise as compared to other PN junction diode
The power loss due to noise is low
It is portable due to the small size and also a lightweight
Reliability
It is economical
Low cost
It has a small size
It is reliable you can use it to vary a capacitance

Disadvantages of varactor diode:

These diodes are specially designed to work in the reverse-biased mode. Hence they are not useful when operating them in the forward bias mode

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Varactor diode applications

The applications of the varactor diode are mainly used in involve within RF design arena. It mostly used in frequency modulations or tunning circuit where the value of capacitance determines the output modulations frequency. Some of the applications of the varactor diode are listed below:

Automatic frequency controller wherein varactor diode is used to set LO signal
It is used in a variable resonant tank LC circuit
It is used in the electronic application
High-frequency radios
Frequency modulator
RF phase shifter
Frequency multiplier
It is used radio receiver for tunning the circuit
Parametric amplifier
Bandpass filters
Voltage controlled oscillators
Ultra-high-frequency television sets
Harmonic generators
Frequency control circuits
Voltage control oscillator is widely used in receiving and transmitting circuit in the field of communication
It can be used in high-frequency areas like Tv tunning and FM radio operations and frequency modulations

Tunnel diode application

Applications of tunnel diode:

Tunnel diode can be used as a switch, oscillator, and amplifier
It is used as an ultra-high-speed switch
It shows a fast response
It is used as an ultra
It is used as a high-frequency component
Tunnel diode acts as a logic memory storage device
It can be used as FM receiver since it is a low current device it is not used more
It can be used in modern military equipment
It can be used as a microwave oscillator at a frequency of about 10 GHz
It is used in nuclear magnetic resource machine
It can be used in satellite communication equipment

Practical application of tunnel diode:

The tunnel diode is mostly used as a relaxation oscillator circuit
It can be used microwave oscillator, which has the frequency above than 10 GHz
It can be used as an amplifier
It is used as a whenever high switching is needed mostly in control system because it has a switching time of the nanoseconds or picoseconds
It is used in satellite communication types of equipment
It is used as a memory storage device
It is used in nuclear magnetic resource machine
It is also used in the military type of equipment like sonars and radars
It has a small inductance, capacitance, and also it has negative resistance for that reason it is used in microwave oscillator and relaxation oscillator

tunnel diode definition

The term tunnel diode also called as Esaki diode, this name comes after Leo saki, It was invented in August 1957 by Leo Esaki, Yuriko, and Takashi Suzuki when they were working at Tokyo Tsushin Kogyo. After in 1973 received the Nobel prize in physics for discovering the electron tunneling effect used in these diodes. A tunnel diode is one type of semiconductor diode that has negative resistance due to the quantum mechanical effect called tunneling. The tunnel diode is a highly conductive, heavily doped PN junction diode in which the electric current decreases as the voltage increases. The tunnel diode is a two terminal device with one n-type of semiconductor cathode and other p-type of semiconductor act as an anode. In tunnel diode electric current is caused by the tunneling effect. The tunneling is the phenomenon of conduction in the semiconductor material in which the charge carrier punches the barrier instead of climbing through i

A tunnel diode is used in high-frequency oscillators, computer, and amplifier. The concentration of the impurity in the normal PN junction diode is about 1 part in 10^8 but in the tunnel diode, the concertation of impurity is about 1 part in 10^3. The diode conducts current both in forward as well as in the reverse direction.

Tunnel diode symbol

Zener diode characteristics

The VI characteristics of Zener diodes shown in the figure given below. This curve shows that when Zener diode if forward bias, it works like a normal diode but when the reverse biased voltage applies across to the Zener diode, the Zener diode breakdown occurs in a different manner.

At Zener breakdown voltage the current stary flowing in the reverse direction, it allows only a small amount of leakage current until the voltage is less than Zener diode

At the certain value of reverse voltage, the reverse current will increase suddenly and sharply. This is an indication that the breakdown has occurred. Breakdown occurs called a Zener breakdown. However, the Zener diode exhibits a controlled breakdown that does damage the device.

This graph shows that Zener breakdown is not exactly vertical shown above which shows that the Zener diode has a resistance. This breakdown voltage of the Zener diode depends on the amount of doped applied. If the diode has heavily doped Zener breakdown occurs at a low reverse voltage, on a different way when the diode is lightly doped breakdown occurs at high reverse voltage. The voltage across Zener is represented by the equation is given below.

V = V_z+I_zR_z

Zener diode characteristics

What is zener diode

Before we learn about Zener diode first let we understand what is a diode?

The n-type semiconductor has a larger electron concentration. This is done by introducing a donor as impurities. Here the n-type refers to the negative charge of the electron.

While in p-type of the semiconductor has larger hole concertation, here p-type refers as to the positive charge of the hole.

What is a Zener diode?

The name of Zener diode was named after American physicist Melvin Zener who discovered the Zener effect. The Zener diode is widely used in all kind of electronic circuit equipment.

The Zener diode is a unique diode which allows the current to flow in one direction like a regular diode but is also permits it to flow in the opposite direction. It allows the flow in the opposite direction when the voltage is above a certain value as Zener voltage. Zener diode consists of a highly doped reversed biased, p-n junction diode while operating in the breakdown region.

In a normal diode, the breakdown voltage is very high and also the diode gets damaged totally if a voltage is above the breakdown diode is applied, but in Zener diodes, the breakdown voltage is not like too much high and does not lead to permanent damage of the Zener diode if the voltage is applied.

A Zener diode is a basically P-N junction type of semiconductor diode, which device designed to operate in the reverse breakdown region. The Zener diode is always connected in reverse direction because it is specially designed to work in reverse direction. The breakdown voltage of the Zener diode is carefully set by controlling the doping level during manufacture.

The symbolic representation of the Zener diode is given below:

Zener Diode

Zener diode characteristics of Zener diode:

At Zener breakdown voltage the current stary flowing in the reverse direction, it allows only a small amount of leakage current until the voltage is less than Zener diode

Zener diode characteristics

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Different types of Zener diodes:

Normal diode
Power dissipation
Forward voltage
Packing voltage
Forward drive current
Maximum reverse current

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Advantages of Zener diode:

High accuracy
Small size
Power dissipation capacity is very high
Low cost

Application of Zener diode:

Voltage regulation
Voltage reference
Switching operation
Clamping circuit
Various protection circuit
Waveform clipper
Voltage shifter
Voltage stabilizer
For meter protection
For wave shaping
As voltage stabilizer

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Conclusion:

We all know that learn about the above topic we understand that this ordinary diode only that it has been doped to have a sharp breakdown voltage.
the diode maintains a stable output voltage irrespective of the input voltage provided the maximum Zener current is not exceeded.
The Zener diode default operational state is in the breakdown region that we seen above. It means it actually starts to work when the applied voltage is higher than the Zener voltage is in reversed biased.
When Zener diode is forward bias, the Zener diode behaves exactly like the normal silicone diode. It conducts with the same 0.7 V voltage drop that accompanies the use of the normal diode.
This diode is mostly used in applications involving, voltage regulations, clipping circuits, and voltage shifters.

This article also gives the various types of diode listed below:

Types of Zener diode

Different types of Zener diodes:

Normal diode
Power dissipation
Forward voltage
Packing voltage
Forward drive current
Maximum reverse current

We have to also explain in details for this diode:

Normal diode: The nominal operating voltage of Zener diode is also known as the breakdown voltage of the Zener diode, depending on the application for which type of diode is being to be used, this is often the most important criteria for which Zener diode selection.
Maximum Zener current: This refers to the minimum current for the Zener diode start operating in the breakdown region.
Power dissipation: This diode represents the maximum amount of power the Zener current can dissipate. Exceeding this power rating leads to an excessive increase in the temperature of the Zener diode which could damage it and also lead to the failure of the things connected to it in a circuit. Thus this factor should be considered when selecting the diode with the user in mind.

Zener diode definition

Definition of Zener diode:

The name of Zener diode was named after the American physicist clearance melvin Zener who discovered the special type of Zener effect. The Zener diode is widely used in all kinds of electronics equipment and mainly used in protecting electronic circuit from overvoltage.

The Zener diode is normal semiconductor type P-N junction diodes operating in reversely biased conditions. The Zener diode is always connected in reverse direction because it is specially designed to work in reverse direction. In other words, the diode which is specially designed for optimizing the breakdown region is known as the Zener diode. The breakdown voltage of the Zener diode is carefully set by controlling the doping level during manufacture.

Zener Diode Symbol

Zener diode application

The Zener diode is widely used as a shunt regulator or voltage regulator. When connected in parallel with a variable voltage source so the diodes reverse breakdown voltage. The main application of this type of diodes as a voltage regulator. Over a voltage protector as a voltage reference.

The Zener diode is used as voltage reference: In the power supply, a many circuit Zener diode finds as a constant voltage provider or a voltage reference. The only conditions are that the input voltage should be greater than apply Zener voltage and also the series resistor should have a minimum value such that the maximum current flow through the device.
Zener diode as a voltage: In DC circuit Zener diode can be used as a voltage regulator or provide a voltage reference. The main use oZ Zener diode lies in the fact that the voltage Zener diode remains constant for a larger change in current. This makes it possible to use a Zener diode as a constant voltage device or a voltage regulator.
Zener diode as a voltage clamper : In a circuit involving AC input source, different from the normal PN diode clamping circuit, a Zener diode can be used The diode can be used to limit the peak of the output voltage to Zener diode at one side and to about 0V at another side of the sinusoidal waveform.

HVAC full form in electrical

What is the full form of HVAC?

High Voltage Alternating Current

What does HVAC mean?

An alternating current call as AC is an electrical current that periodically reverses direction in contrast to a direct current that flows in only one direction. These currents typically alternate at higher frequencies than those used in power transmission so HVAC is widely used in the transmission and distribution system to reduce electrical losses.

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What is converter

Definitions:

The use of the word converter in power electronics which is often used as describing several unrelated pieces of equipment or performing a different function has added to this confusing matter, A converter has a lot of meaning but often time you can really understand what it really meant. A converter converts the voltage of an electrical device, usually alternating current (AC) to direct current (DC). It changes the voltage of an electrical power source and it is usually combined with other components to create a power supply. A converter converts AC to DC, detect amplitude modulated radio signals, supply polarized voltage for welding.

Types:

The basic difference between various types of converters is that they vary in their nature and the devices they support.

Analog to digital converter (ADC): This type of converter is a device that converts the input analog voltage to a digital number proportional to the magnitude of the voltage or current form. Some non-electronic or partially electronic device, like rotary encoder, can be considered as ADCs.
Digital to analog converter (DAC): It is a device that converts a digital code to an analog signal, DAC are found in CD players, digital music players and PC sound cards.
Digital to digital converter (DDC): It is a device which converts one type of digital data to another type of digital data.

Advantages of the converter:

Faster dynamic response.
Highly reliable.
Highly efficient.
Negligible maintenance.
Very small size.

Disadvantages of a converter:

Poor current overload capacity.
Low power factor.
The good quality automatic regulators are more expensive than other types of mechanical regulators.

Difference between inverter and converter

The converter has a lot of meaning but often times you can really understand what it really meant. For example in electronics, we have understood easily language that the voltage converter is a device that converts AC power to DC power. It changes the voltage of the electrical power source and is usually combined with other components to create a power supply the inverter is defined as an electrical device that converts direct current to alternating current, the converted AC can be at any required voltage and frequency with the use of appropriate transformers switching and control circuits.

The main difference between an inverter and a converter is given below:

The inverter is an electrical device that converts the voltage from direct current to alternating current while in Converter is an electrical device that converts the voltage from alternating current to direct current.
There are different types of inverters square wave inverters, Quasi-wave, or modified square wave inverters pure sine wave inverters whose converter has three forms analog to digital, digital to analog, and digital to digital form.
Inverter is used to convert DC electricity from solar panels, batteries, or fuel cells to AC; micro the inverter for converting DC power from solar panels to AC for the electric grid; UPS uses inverter to supply AC power when mains power is unavailable, induction heating while converter converts AC to DC detect amplitude modulated radio signals, supply polarized voltage for welding.
One of the disadvantages of the inverter is that it is not ideal for inductive AC and motor load, sensitive electronic devices can be damaged by poor waveforms by low batteries but in convert has poor current overload capacity, better quality automatic regulators are more expensive than mechanical regulators.

A key difference between a Converter and an Inverter:

Inverters are typically a lot more complex compared to the converters.
A converter is used in pretty much all applications while the inverter is used in uninterruptible power supplies.
Inverter changes voltage as well as type, A converter changes the voltage but doesn't its type while an inverter changes voltage as well as type.

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1. Difference between UPS and inverter

Difference between TDMA FDMA CDMA

This page describes FDMA versus TDMA versus CDMA provides a difference between FDMA, TDMA and CDMA technologies. This post also describes multiple access techniques to make use of common resources by multiple users or subscribers.

FDMA:

FDMA stands for frequency division multiple access, Here all entire band of frequencies is divided into multiple RF channel. Each carrier is allocated to different users.
Segment the frequency band into disjoint subbands.
Every terminal has its own frequency uninterrupted.
Filtering in the frequency domain.
FDMA is simple. established, robust.
FDMA is inflexible, frequencies are a scarce resource
Cell capacity is limited.
FDMA is a hard handoff.
Power efficiency reduced.

TDMA:

TDMA stands for time division multiple access, here entire bandwidth is shared among different subscribers at fixed predetermined or dynamically assigned time slots.
Segments sending time into disjoint time slots demand driven or it would be fixed patterns.
All terminal are active for short periods of time of the same frequency.
Synchronization in the time domain.
TDMA is established fully digital, flexible.
TDMA is guard space needed, synchronization difficult.
Cell capacity is limited.
TDMA is a hard handoff.
When we are using TDMA full power efficiency is possible.

CDMA:

TDMA stands for time division multiple access, here entire bandwidth is shared among different subscribers at fixed predetermined or dynamically assigned time slots.
Spread the using orthogonal codes.
All terminals can be active at the same place and also at the same moment uninterrupted.
Signal speration for code puls special receivers.
CDMA is flexible, less frequency needed soft handover.
CDMA is a complex receiver, need more complicated power control for senders.
No absolute limit on channel capacity but, it is interference limited for a system.
CDMA IS soft handoff.
When we are using CDMA full power efficiency is possible.

Difference between half wave rectifier and full wave rectifier

The half wave and full wave rectifier have a significant difference. A rectifier converts AC voltage into pulsating DC output voltage. A half wave rectifier is an electronic circuit which converts only one half of the AC cycle into pulsating DC output. On the other hand, full wave rectifier is an electronic circuit which converts the entire cycle of AC into pulsating DC output. This page gives the half wave vs full wave rectifier provides the difference between half wave rectifier and full wave rectifier

Half wave rectifier:

A rectifier which rectifies only one half of each AC supply.
The frequency of the output signal is exactly the same as that of the input signal.
Half wave rectifier gives discontinuous and pulsating DC output, Half wave rectification involves a lot of wastage energy.
Half wave rectifier is unidirectional.
Half wave rectifier efficiency around 40.6 %.
Half wave rectifier is only one diode is required.

Full wave rectifier :

A rectifier which rectifies both halves of each AC input cycle is called as full wave rectifier
It gives continuous and pulsating output.
The frequency of the output signal is double that of the input signal.
A full wave rectifier is bi-directional.
Half wave rectifier efficiency around 81.2%.
Full wave rectifier varies from 2 to 4, in case of a bridge rectifier.

A main key difference between half wave rectifier and Full wave rectifier:

Half wave rectifier is a low-efficiency rectifier while the full wave rectifier is high efficiency.
The losses due to saturation of the DC core in half wave rectifier and full wave rectifier also create a significant difference. The half wave process DC saturation of core, but this problem can be overcome in the full wave circuit.
Full wave requires more electronic components as compared to half wave rectifier. Thus requires double the number of diodes.
The ripple factor in case of half wave rectifier is compared to the full wave rectifier, for half-wave rectifier it is about 1.21 but for the full wave rectifier, it is about 0.482.
The full wave circuitry does not possess DC saturation of the transformer core because of the current in the secondary winding of the transformer and in opposite directions.
A half wave rectifier hs good voltage regulation however full wave rectifier provides better voltage regulation as compared to half wave rectifier.
Half wave rectifier does not require centre tapping of the secondary winding of the transformer while full wave rectifier centre tapping of the secondary winding of the transformer.
The fundamental ripple frequency in case of half wave rectifier is f, supplied input frequency 50 Hz while in twice the supplied frequency 2f (100Hz) in case of full wave rectifier.
The peak inverse voltage in case of half wave rectifier is equivalent to the maximum value of applied input voltage while in peak inverse voltage of full wave rectifier is twice the maximum value of applied input voltage.

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Center tapped full wave rectifier vs bridge rectifier

ECSTUFF4U for Electronics Engineer

Page

Types of diode

Varactor diode symbol

Characteristics of varactor diode

tunnel diode symbol

Characteristics of tunnel diode

Advantages and disadvantages of Tunnel diode

Advantages of tunnel diode:

Disadvantages of tunnel diode:

Advantages and disadvantages of varactor diode

Varactor diode applications

Tunnel diode application

tunnel diode definition

Zener diode characteristics

What is zener diode

Types of Zener diode

Zener diode definition

Zener diode application

HVAC full form in electrical

What is converter

Difference between inverter and converter

Difference between TDMA FDMA CDMA

Difference between half wave rectifier and full wave rectifier

Half wave rectifier:

Full wave rectifier :

A main key difference between half wave rectifier and Full wave rectifier:

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