- The document discusses winding fundamentals for DC machines, including definitions of terms like coil, coil span, double layer winding, commutator segment, and commutator pitch.
- It provides examples of calculating coil span and explains lap and wave windings, including how to number coils and connect them to commutator segments.
- For a 16-slot, 4-pole lap winding example, it shows how the coils are numbered and connected in a progressive fashion from left to right on the commutator.
The armature winding is the main current-carrying winding in which the electromotive force or counter-emf of rotation is induced.
The current in the armature winding is known as the armature current.
The location of the winding depends upon the type of machine.
The armature windings of dc motors are located on the rotor, since they must operate in union with the commutator.
In DC rotating machines other than brushless DC machines, it is usually rotating.
Winding
What is Armature winding?
Terms related to armature winding.
Single layer and double layer windings.
Comparison between closed and open windings.
Types of DC armature winding.
Types of AC armature winding.
The armature winding is the main current-carrying winding in which the electromotive force or counter-emf of rotation is induced.
The current in the armature winding is known as the armature current.
The location of the winding depends upon the type of machine.
The armature windings of dc motors are located on the rotor, since they must operate in union with the commutator.
In DC rotating machines other than brushless DC machines, it is usually rotating.
Winding
What is Armature winding?
Terms related to armature winding.
Single layer and double layer windings.
Comparison between closed and open windings.
Types of DC armature winding.
Types of AC armature winding.
An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field with a stationary armature.
An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field with a stationary armature.
Textile fabric may be define as an assembly of fiber, yarn or combination of these. There are several ways to manufacture a fabric.To produce woven fabric yarn preparation is essential.Good preparation means good weaving,Good weaving =Quality fabric.
The branch of Civil Engineering which deals with the design, construction and maintenance of the railway tracks for safe and efficient movements of trains is called Railway Engineering
BALLAST
RAILS
SLEEPERS
POINTS OF CROSSINGS
POINTS OF SWITCH
The rolled steel sections laid
end to end in two parallel lines
over sleepers to form a railway
track are known as RAILS The rails used in the construction of railway track can be divided into the following three types :
(1) Double Headed Rails (D.H. Rail)
(2) Flat Footed Rails (F.F. Rail)
(3) Bull Headed Rails (B.H. Rail)
Introduction to smith Chart
Introduction to smith Chart
Normalized Impedance
Constant Resistance Circles
Constant Reactance ‘Arcs’
Plot a Complex Impedance
What about Admittance?
Analysis of Single stub Tuner
VSWR and Transmission Lines
Analysis of Single stub tuner
Analysis of Double-Stub Tuner
Difference between single stub matching and double stub matching
A 50 ohm transmission line is terminated to load of 25+50j. The length of the transmission line is 3.3 lemda.
Find:
(a)Reflection coefficient
(b)VSWR
(c)Input impedance
(d)Input admittance
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
2. Winding in Armature
• Armature of D.C machines carries a closed
winding.
• Closed winding means that the coils forms a
closed circuit.
• The junction points of the coils are on copper
bars called commutator segments.
• These commutator segments are insulated
from each other by insulation.
4. Coil
• A conductor is placed in a designated slot
• Two conductors from two different slots
when connected at one end forms a coil
• Hence each coil has two coil sides.
• Spacing between two coil sides are close to
180° electrical to occupy a place under
opposite poles.
5. Coil span
• Spacing between the two coil sides is termed as
coil span and counted by number of slots
between the sides.
• Coil Span= No. of slots (S)/ No. of Poles (P)
• For 30 slots, 6 poles winding, coil span is 5.
• Let the slots be numbered serially as 1, 2,…, 30.
• If one coil side is placed in slot number 7, the
other coil side of the coil must occupy slot
number 12(= 7+ 5).
6. Double layer winding
• To maximize number of coils for a given number of
slots, each slot now divided into two layers separated
by insulation.
• One slot carries two coil sides they belong to two
different coils.
• For slot No. 7, the upper coil side is numbered as 7
and the lower coil side is 7'.
• For a given coil one coil side is placed in the upper
deck of one slot, the other side will be in the lower
deck of another slot.
• Since there are two layers, the winding is two layer
winding.
7. Numbering a coil
• Suppose S = 20 and P = 4, then coil span is 5.
• Let the upper coil side of this coil be placed in
slot number 6, the other coil side must be in
the lower deck of slot number 11.
• The coil should now be identified as (5 - 11').
• In other words coil sides of a coil are
numbered depending on the slot numbers in
which these are placed.
8. Commutator segment
• Two coil sides (belonging to two different
coils) terminate On a Commutator segment.
• 2S being the total number of coil sides,
number of commutator segments must be
equal to S, number of slots.
• Commutator segments can also be numbered
as 1,2,…,30 in order to identify them clearly.
9. Commutator pitch
• The separation of coil sides of a coil in terms
of number of commutator segments is called
the commutator pitch, yc.
• The value of yc decides the types of winding
(lap or wave).
• For example, in case of lap winding yc = 1.
10. Terminology
• Pole Pitch
• Coil span or coil pitch
• Back Pitch
• Front Pitch
• Pitch of a winding
• Resultant Pitch
• Commutator Pitch
11. Pole Pitch
• Distance between adjacent poles
• (Periphery of armature)/(Number of poles)
12. Coil span or coil pitch
• Periphery of armature spanned by two sides of a
coil
• Measured in terms of armature slots or
conductors
• Full pitch wdg.=coil span is 1800 electrical (Pole
pitch=coil pitch)
• Short pitched wdg (Coil pitch<pole pitch)
• 36 slots, 4 poles, coil span=36/4=9,
• If slos=3, Ys=35/4=4
13. Pitch..
• Back Pitch=YB=Distance by which a coil
advances on back of the armature
• Front Pitch=YF= Number of armature
conductors are spanned on the front of the
commutator
• Pitch of a winding=Y=Distance round the
armature between two successive conductors
directly connected, Y=YB-YF (Lap), Y=YB+YF
(Wave),
14. Pitch..
• Resultant Pitch=YR=Distance between
beginning of one coil and beginning of the
next coil to which it is connected
• Commutator Pitch=YC=Distance between
segments to which two ends of one coil are
connected
22. Lap winding
• Suppose we want to make a lap winding for a
P = 4 pole D.C machine having a total number
slots S = 16.
• So coil span is 16/4 = 4. Commutator pitch of a
progressive lap winding is yc = +1.
• To view the coil sides / coils, we must look
below from above the slots as depicted in
figure
24. Lap winding…
• Once we number the slots, the numbering of
the coil sides gets fixed and written.
• The upper coil side present in slot number 1 is
shown by firm line and named 1 while lower
coil side is shown by a dashed line (just beside
the upper coil side) and named as 1'.
• Let us now see how coils can be drawn with
proper termination on the commutator
segments.
25. Lap winding…
• Since the coil span is 4, the first coil has sides 1 and 5' and
the identification of the coil can be expressed as (1 - 5').
• Let us terminate coil side 1 on commutator segment 1. The
question now is where to terminate coil side 5'?
• Since the commutator pitch yc is +1, 5' to be terminated on
commutator segment 2 (= yc +1).
• In D.C armature winding all coils are to be connected in
series.
• So naturally next coil (2 - 6') should start from commutator
segment 2 and the coil side 6' terminated on segment 3 as
shown in figure (next).
• It may be noted that in a lap winding there exist a single
coil between any two consecutive commutator segments.
26.
27. Lap winding..
• It can be seen that the second coil 2 - 6' is in the
lap of the first coil 1 - 5', hence the winding is
called lap winding.
• The winding proceeds from left to right due to
our assumption that yc = +1.
• Such a winding is called progressive simplex lap
winding.
• It can be easily shown that if yc is chosen to be -1,
the winding would have proceeded from right to
left giving rise to a retrogressive lap winding.
28. Lap winding..
• One can make first a winding table and then
go for actual winding.
• By now it is clear that to go ahead with
winding, two information are essential;
namely the number of coil sides of a coil and
the number of commutator segments where
the free ends of the coil sides will be
terminated.
30. Wave winding
• In this winding these coil sides of a coil is not
terminated in adjacent commutator segments,
i.e., yc ≠ 1.
• Instead yc is selected to be closely equal to two
pole pitch in terms of commutator segments.
• Mathematically yc ≈ 2S/P.
• Let us attempt to make a wave winding with
the specifications S = 16 and P = 4. Obviously,
coil span is 4 and yc = 8.
31. Wave Winding
• The first coil is (1 - 5') and is terminated on
commutator segments 1 and 9.
• The second coil (9 - 13') to be connected in series with
the first and to be terminated on commutator
segments 9 and 1 (i.e., 17').
• Thus we find the winding gets closed just after
traversing only two coils and it is not possible to carry
on with the winding.
• Our inability to complete the wave winding will persist
if 2S remains a multiple of P.
• It is because of this reason expression for commutator
pitch yc, is modified to yc = 2(S ± 1)/P.
32. Wave Winding
• In other words, number of slots, should be
such that 2(S ± 1) should be multiple of P.
• It can be shown that if +ve sign is taken the
result will be a progressive wave winding and
if –ve sign is taken the result will be
retrogressive wave winding.