Practical use of Inductor

 

How to find value of inductor  for specific application:-

We know that in inductor current lags behind the voltage because of lenz's law. Depending upon load check the voltage and current. Select that maximum value of voltage and current with phase and use following formula 

Z = amplitude of Voltage with phase/ amplitude of current with phase

This value can be find by any virtual simulator software.

                       Z=R + j(XL + Xc)                              where   XL = 2 πfL 

Here L is the value of required inductor inductance in henry, according to supply frequency type of inductor is decided.

When current flows through an Inductor  it acts as short circuit and when get fully charged by magnetic energy it behaves like a open circuit thus when it get discharged provides a stable and controlled curret to the load. So this is mostly used where you need a controlled current supply independent of source and load disturbances.

We can find out inductance of an Inductor with the help of following formula

                    

L =μ

N2 A  l

$${\mathrm{\mu r\times \mu 0=\mu \; =\; permeability\; of\; the\; core}}^{}$$

N= Number of turns wrap around the core

A=area of the core in meter square

l= length of Inductor core in meters 

Charging of  Inductor:-

What an  Inductor does in a circuit :-

 In DC electronics circuits An Inductor is mainly used to provide current control and provide steady current to electronic components. We know that electronic components get damaged or give poor performance because of current spikes and abrupt change in current amplitude. When we connect a Inductor in series with the desired components then current through the components does not rise or fall abruptly but goes slowly to peak from zero value. Along this Inductor also helps to maintain continuous steady current flow with  few mili seconds current fluctuations.

You can see it by a practical example connect a LED in series with resistor and Inductor and give it supply through a 9 V battery. 

          

                                          Fig 1.

In the above circuit brightness of LED bulb will rise slowly upto maximum value and on turn off comes down to zero slowly because of inductor as brightness of led is directly proportional to current, where as we can not observe this change practically. We can watch this change on a virtual simulator software very clearly.

In AC electronics circuit inductor is used to produce electromagnetic waves to provide wireless transmission for communication purposes.

Charging equation of Inductor 

I = I0(1-e^-t/τ )

Discharging equation of Inductor 

I = I0.e^-t/τ 

Where τ =L/R time constant of Inductor

An Inductor takes 5τ  time to get fully charged.

Inductor Practical applications:- 

1. In railways inductors are termed as SL ( SMOOTHING REACTORS) which is used in conventional type of Electric Locomotives to provide smooth and steady electric current to six DC Series motors.

2. When two inductors are placed face to face they are called transformer and used to transfer power with same frequency from one point to other without any electrical connection between then thus acts as a isolation device.

3. Inductors are used in receivers  to produce desired tuning frequency.

             f= 1/2π√LC

4 .Inductors are used in hartley oscillators to produce desired. frequency oscillations.

5. Inductors are also used for impedance matching.

6. Inductors are also used in relays, motors, Generators, speakers, sensors and chokes etc.

7. Inductors are also used in antenna to produce electromagnetic waves for communication.

Author:- Amarjeet Singh Jamwal authored articles on Basic Electronics Engineering, Electric Traction, and Electronics Practical for INFO4EEE Website