||diac|| definition || construction || symbol || application ||

August 28, 2020 0

DIAC

Definition:-

Diac is important device used to triggered triac. Called as triac without gate terminal due to typical construction.

Construction of DIAC:-
Diac basically two terminal device. It is such a combination of semiconductor layers that allows ori to trigger in both directions. DIAC used triggered for triac.

Semiconductor leyers show in Diagram. There are two terminals MT1 (main terminal 1) and MT2. (main terminal 2).

P1 - n2 - P1 - n1, which is equivalent to an SCR.

MT1is Anode one and MT2 is Anode two.
the equivalent circuit of diac is two scr connected back to back to form DIAC

Diac is a unidirectional or bidirectional device.  This question is always asked.  But Diac is a unidirectional device.

DIAC symbol:-

I-V characteristics of DIAC:-

Application:-

  • Lamp dimmer. 
  • Fan speed regulator. 
  • Temperature controller. 

Disadvantage:-

  • Low power device. 
  • Dose not have control terminal. 
Request :
Please Sher and comment. 

state of superposition therom,steps, application, problem and solution.

August 25, 2020 0

State of superposition therom. 

Superposition therom:-

In any linear network of the response in any element is equal to the Aljebric sum caused by individual source acting alone while all other source inactive is called as superposition therom

Superposition therom steps:-

                Response due to v1 source
 

      According to the superposition therom

Application of superposition therom:-

  • it is usedfull in circuit analysis. 
  • It helps us to determine the voltage across a component or current through branch by calculating the effects of each source Indivisivally and determining the combined effect of these source. 
  • The superposition therom can be used for A.C as well as D.C network. 

superposition theorem problems with solutions pdf:-

Click here

What is MCB? Working, types, function, rating, full form.

August 24, 2020 0

(MCB) Miniature Circuit Breaker.

In today's post, we will tell you about MCB, what is MCB, how does it MCB working. MCB function, MCB rating, MCB full form and MCB types. Let's start.


What is a MCB? 

(MCB) Miniature Circuit Breaker

MCB is an electrical circuit. Electrical MCB or MCB electrical which automatically turns off when power is low or overload, short circuit, line fault. So that there is no damage to the electrical machine or electrical tools. Also, do not harm anyone. MCB full form for Miniature Circuit Breaker.

A miniature circuit breaker is an automatically functioning circuit. Short or overload, the power that is turned off automatically when there is a short circuit. Prior to MCB, fuses were widely used. But the fuse had several drawbacks as this fuse was not secure. 


Fuse could not recognize any problems. Because of which electrical equipment used to go bad. The fuse never closes automatically when there is a short circuit.


If the same thing happens with the MCB, its key key is automatically locked.

The current supply automatically turns on when the key is on again. You can also operate MCB manually. And there is no security risk as well. It is completely untouched.

The MCB costs more than the fuse. MCB is very expensive.



MCB working:-


The main two types of speed method in MCB

1. Overload effect. Overload 


2. Electromagnetic effect 


Overload effect - In overload effect, when the current flowing through the bimetallic strip, the current is flowing too much for a long time. The bimetallic strip is folded automatically due to the heat, by turning it, the mechanical latch is loosened which is connected to the operating system, it opens the circuit and the current that is going through the MCB. Stops and this whole process is called the overload effect We know the whole process as overload effect.



Short Circuit - The current comes to its peak at the time of short circuit due to which the submarine receives electromagnetic effect and vibrates from its place, while the submarine is connected to the culvert and tripping cuckoo MCB. And the submarine that moves is very fast, due to which the kundi. Open immediately and the current that is coming stops, and the circuit closes. We know this whole process as short circuit.



MCB function: -

If any abnormalities are found in the MCB electrical circuit, it immediately disconnects the circuit from the power supply.  If there is a fault in the circuit due to which the electric current is spreading more.

For example, in the case of over load and short circuit, the current flowing through the circuit is much higher than the normal situation.  Such condition automatically binds the MCB electrical power supply.


According to the law of nature, the person who exists has to be destroyed.  The condition of the fuse is similar today.  Fuses of some type were used in the protection of electrical circuits, today the MCB has replaced it.



Industrial and domestic two places where fuses used to be before, but today MCB is seen there.  Because the reliability and gain of the MCB is more than the fuse, these changes are beneficial.


MCB types:-

There are three types of MCBs which are based on the fluctuations coming from it.  

In case of type 


  • B type 
  • C type 
  • D type 


B type MCB, if the current passes at the rate of 20 to 30 then it stops.  

This B type MCB is used in homes. In MC type of C type, if the current is 50 to 100

In MC type B, if the current passes at the rate of 20 to 30, it stops.  

This B type MCB is used in homes. In case of MCB of C type, the current will be closed at the rating of 50 to 100, then it will be closed. This type of MCB is used in both domestic and industrial.  

D type MCB will be closed if current rate of 100 to 200 flows. 

This type of MCB is used only for industrial use such as x ray machine, welding machine, 3ite 3R industrial use which use huge amount of electricity.


Advantages of MCB :-

1) .MCB is easily known in which place the fault has occurred or in which area. 

2).MCB can be easily turned on . 

3).(Fuse) catches the power of electricity more quickly. 

4).There are very few expenses to fix MCB.  


Disadvantages of MCB 


1) MCB is more expensive than fuse.

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what is zener diode||working, diagram, characteristics, effect,application.

August 21, 2020 0

Zener diode ( zener diode kay hai) :-

hello guys!  Today, I will tell you in detail about what is zener diode (what is a Zener diode and its working, application, formula, characteristics, diagram,  zener effect), let's start.

what is Zener diode?

A Zener diode is a diode that not only allows current to flow from its anode to the cathode but also allows the current to flow in the reverse direction when the voltage reaches the Zener voltage.

It is a silicon semiconductor device.  

It is named after the clarence zener that discovered the zener effect.

The p - n junction of Zener Diode is highly dope d.

Normal diodes breakdown at reverse voltage and are not designed to operate in the breakdown area.

But Zener diodes operate in breakdown area.  Zener reverse breakdown is caused by electron quantum tunnelling, which is caused by a large electric field.

Zener diodes rely more on avalanche breakdowns.  Zener diodes use both the zener effect and avalanche breakdowns.

The zener effect occurs at low voltage and avalanche breakdown occurs at high voltage.

Zener diodes are used in all types of electronic devices.

The zener diode is a common block of electronic circuits.
Zener diode diagram. 

Zener diodes are used for stable power supply.

And they are used to protect the circuits from overloadvoltage.

 working: -

A normal diode, when the reverse bias occurs above the reverse breakdown voltage, allows some current to flow. It is called leakage current.

When the reverse bias breakdown voltage increases then the diode allows more current to flow due to avalanche breakdown.

Because of this diode overheating can be ruined forever.

Zener diodes also have the same properties as normal diodes, but are designed to have a lower breakdown voltage, called a Zener voltage.

A reverse bias zener diode exhibits controlled breakdown compared to a normal diode and the current (current) is what keeps the voltage close to the Zener breakdown voltage across the Zener diode.

For example, if a zener diode has a Zener breakdown voltage of 2.1V, its voltage drop also remains around 2.1V.

So therefore Zener diode can be used like voltage stabilizer or voltage regulator.

 No formula for zener diode in my opinion.

Characteristics: -

construction: -

The mechanism of Zener diode depends on the excessive doping of its pn junction.

The depletion region formed in the diode is very thin and the electric field is quite strong.

The electric field is too high even for the reverse bias voltage of 5V due to which electrons move from the valence band of the p type material to the conduction band of the n type material.

The breakdown voltage for commonly available zener diode can vary from 1.2V to 2007.

In diodes that are less doped, avalanche breakdown is greater than Zener breakdown.

Due to which the breakdown voltage in such devices is high.

What is avalanche breakdown?

The depletion layer of Zener Diode is wide and their breakdown voltage is also high.

In those diodes, the current increases in breakdown voltage very fast, which reduces the reverse resistance of the diode.  A reverse leakage current flows below the reverse breakdown voltage.

Due to which electrons and holes (holes) go into depletion layer.  Now the voltage is equal to the reverse breakdown voltage.

In the depletion layer, the existing electrons and holes fall under a strong electric field, which is rapidly accelerated.

Electrons and holes collide with other atoms and eject electrons from their atomic bonds, this is called impact ionisation.

Thus more electron / hole pairs are formed which are greatly accelerated by electric field.  These electron holes in turn ionize the other atom, which causes a very sharp increase in the reverse current of the diode.  This process is called avalanche breakdown.

zener effect :-

The zener effect is a breakdown of a type of reverse biased PN junction afea.

Due to the high amount of dope of p and n substances, they become good conductors and the depletion layer also becomes thin, the electric field across the depletion layer becomes very strong.

Due to which the holes and electrones which are at low voltage cross the depletion layer and are added which causes reverse current.

This effect occurs mostly in Zener diodes which have low reverse breakdown voltage.

 Application: -

It is used for voltage reference and shunt regulator, and for controlling voltage in small circuits.  

Zener Diode is used in surge protector to limit transient voltage spikes 

Zener diode's noise, which is caused by avalanche breakdown, is used in random number generator.  

waveform clipper-zener diode is used to clip the waveform.  When the two Zener diodes are placed in front of each other in the range, they clip both the semicircles of the input signal.  

Waveform clippers are used not only to resize the signal but also to protect circuits from voltage spikes that are connected to the power supply.  

voltage shifter - It works like a voltage shifter in a circuit with a Zener diode in resistance.  This circuit reduces the output-voltage equal to the breakdown voltage of the Zener diode.

Voltage regulator - Zener diode is used to regulate voltage.  Zener diodes are mounted in the voltage regulator circuit to control the voltage applied to the load.  As in a linear regulator.

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What is UJT v-i characteristics, working,theory, symbol.

August 20, 2020 0

What is UJT (uni junction transistor)?

Hello friends!  Today I will read you in this post about what is UJT ? v-i characteristics of UJT, ujt working, UJT triggering circuit, ujt relaxation oscillator, ujt characteristics theory, ujt symbol. Its structure, and procedure.  So let's start

what is UJT?

Full form of UJT is uni - junction transistor.  It is a three-terminal semiconductor device.  It has only one pn junction so it is called unijunction transistor.

construction of unijunction transistor (structure) UJT uses a low doped n type silicon rod.  
What is UJT (uni junction transistor)?

The more doped p-type material is diffused on one side of this rod.  The terminal which connects to the p type region is called the emitter terminal (E) and the two terminals which are connected at opposite ends of the n type region are called base1 (B1) and base2 (B2).

Working UJT :-
When the voltage between emitter and base1 is zero then UJT does not conduct any operation and n type rod acts as a resistor.  

But we see that a small leakage current flows due to reverse bias junction.  

When we gradually increase the emitter voltage, the resistance between the emitter and base1 decreases.  

When the emitter voltage increases enough that the junction forward bias occurs, the emitter current starts flowing.  

This is because holes in the more doped p-type region enter the n-type region and are joined with electrons of the n-type region.

Thus the movement of the uni junction transistor begins.

Symbol of UJT:-
Symbol of ujt.

v-i characteristics UJT:-
v-i characteristics of ujt

UJT characteristics theory:-

UJT Characteristics : The UJT characteristic is as shown in diagram.This is emitter voltage ( on Y - axis ) versus emitter current ( on X - axis ) characteristics .

 For the emitter potentials less than V. ( peak point potential ) the UJT is in the OFF state and the magnitude of le is not greater than IEo. 

The current lEo is very similar to the reverse leakage current ICo of a bipolar transistor . This region is known as the cut off region .

As the emitter potential increases and reaches Vp = ( n  VBB + VD ) the UJT starts conducting . Then with increase in emitter current IE the emitter voltage decreases as shown in Diagram. 

The reduction in voltage across UJT is due to the reduction in resistance RB1 with increase in the value of lE.

This region of operation is known as a " Negative Resistance " region . It is a stable region and can be used in various applications . 
Eventually the " Valley Point " will be reached which marks the end of negative resistance region . If we increase lE further , the UJT will enter into the saturation region . 

The saturation region is a positive resistance region as Ve increases with increase in lE .

UJT triggering circuit:-
Ujt triggering circuit.

UJT relaxation Ocilator:-
Ujt relaxation Ocilator.

applications of UJT (Application):- 

Its applications are as follows: 

  • It is used as a triggering device in SCR and TRAIC.  
  • UJT is used to generate non sinusoidal waves in relaxation oscillator.  
  • It is used to control the speed of AC and DC motor.  
  • UJT CT 3941 saw occurs in tooth wave generator and phase control circuits.  


Request: - If this article has been helpful for you, then definitely share this with your friends and if you have any other questions related to your electronics, then you can comment by commenting.  thanks.