Transformers, Electrical Engineering

Assignment Help:

AC Operation of an iron core

1428_Transformers.png

 

 

 

563_Transformers 1.png

 

Hence, if a wattmeter were used to measure the power delivered over a full period of the waveform (which will also be the average power delivered over a long period of time), the answer should be zero.  In practice, there will be a finite energy loss recorded, which is found to be much larger when the coil is wound on a conductive former than when it is air cored.

The energy loss is attributed to:
 
 
1) 'Copper losses', i.e. loss due to current flowing through the resistance of the windings, (P=iR).This power loss occurs whether the
core is air cored or not.

2) 'iron losses'. These arise due to two causes:
 
a)  the hysteresis loss due to the energy dissipated in continually reversing the magnetisation of the core. The energy taken per cycle is the area of the hysteresis B/H curve.

b) Eddy current losses due to  induced currents circulating within the conductive core of the coil. These are induced by the changing current in the coil and circulate in such a way as to try to oppose the change in the coil current. They are minimised by laminating the core to increase the path resistance for the circulating current and hence reduce its value. Since Power = i.R, reducing the current reduces the power even though the resistance is increased.

A transformer is produced by winding a second coil onto the former.

1393_transformer is produced by winding a second coil.png

 

Note the polarity of the currents. The current in the primary coil creates a flux in the core with a direction according to Maxwell's RH corkscrew rule. The current induced into the secondary coil is in such a direction as to try to oppose the original flux change in the core.

 

 


Related Discussions:- Transformers

Characteristics of stepper motors - stepper motor , Characteristics of Ste...

Characteristics of Stepper Motors The main  characteristic of stepper  motors is torque  versus stepping or  pulse  rate. It give the  variation  of torque as a function of pu

Find the magnetic-field force exerted on the moving bar, Consider the arran...

Consider the arrangement shown in Figure. A conductor bar of length l is free to move along a pair of conducting rails. The bar is driven by an external force at a constant velocit

What minimum value of coupling resistance, Q. It is desired to have a sag o...

Q. It is desired to have a sag or tilt of no more than 10% when a 50Hz square wave is impressed on an amplifier stage. The output circuit resistance is Rv=1K. What minimum value of

Discuss applications of dielectrics, Discuss applications of dielectrics. ...

Discuss applications of dielectrics. Application of dielectrics: For various applications various properties of dielectric materials are required as: electrical, mechanical

Shunt dc motor, Shunt DC motor In this arrangement, the armature and f...

Shunt DC motor In this arrangement, the armature and field coils are connected in parallel (the motor is called 'shunt connected').     Analysis With refere

Electrical System Design, List four sources of information which are essent...

List four sources of information which are essential to the designer of this electrical installation

Ultrasonic Sensor Help for Seventh Grader, What are ultrasonic sensors made...

What are ultrasonic sensors made of? What is a good online source to find information on a basic level about ultrasonic sensors?

C R O DELAY LINE, WHAT IS THE FUNCTION OF DELAY LINE IN CRO

WHAT IS THE FUNCTION OF DELAY LINE IN CRO

Circuits, Circuits Typical  electronics circuits  are created  out  of...

Circuits Typical  electronics circuits  are created  out  of a basis  set of primitive elements such  as capacitors, voltage sources,  resistors,  transistors and inductors. T

How numbering plan is achieved in modern telephony, Q. How numbering plan i...

Q. How numbering plan is achieved in modern telephony? Ans: The purpose of numbering plan is to uniquely identify every subscriber connected to a telecommunication network.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd