1. DC Machines and Drives . Books
Principle Of Electrical Machines (V.K. Mehta, Rohit Mehta)
Electric Machinery Fundamentals (CHAPMAN J STEPHEN)
Electrical Technology Volume II (B.L.Theraja)
Basic Concepts
Lecture # 01

2. Basic Quantities and Definitions
Energy? Types of Energy?
Conversation of Energy
What is electricity /electrical Energy?
- flow of electric charge.
Charge . (atom, Electrons Protons, Neutrons)
1- Current
2- Voltage
3-Resistance

3. We need electric machines in almost every field of our life today.
“Electromechanical device that converts electrical energy into mechanical energy is called motor ”
while
“A device that converts mechanical energy into electrical energy is called generator”
We need electric machines in almost every field of our life today.
From transportation to construction.
Cars, Clocks, Drills, Fans, Fridges, Vacuum Cleaners, Water pumps, Washing Machines, Computers, Lifts, lathes, robots etc.
Click on VIEW and select SLIDE SHOW to view the presentation.

4. Machines are categorized or classified on the basis of input supply, construction and operation principles.
Input supply ?
In electrical system there are two kinds of supply systems means power source are provided.
1. AC system.
2. DC system.
Alternating Current (AC).
An electric current that reverses direction 
sinusoidally. Concept of phases and frequency.
Direct Current (DC).
Current flow is unidirectional and of constant magnitude . Negative and positive terminals (battery, cells)

5. Direct Current (DC) Machines
Type of Electric Machines
Classification of Machines
Electric machines
Alternating Current (AC) Machines
Direct Current (DC) Machines
Synchronous
Induction
Three-Phase
Single-Phase
Self Excited
Separately Excited
Series
Shunt
Compound

6. Construction and working of Electric machines
An electric motor consists of many parts.
Stator : The stationary part of an electric motor is called the stator. The stator will be provided with permanent magnets or windings.
Rotor: The rotor is the part that actually converts electrical energy into mechanical energy. The rotor is connected to the mechanical load through the shaft. These come in various designs.
For Example if we are talking about Induction or asynchronous motor,
(a) Squirrel cage rotor,
(b) Slip ring rotor or wound rotor or phase wound rotor.
Or if we are talking about synchronous motors
(a) Salient pole (100 to 1500rpm.) (b) non salient pole(>1500rpm).

7. Field windings: conductors used to produce electromagnetic field.
Armature windings: conductors in which output voltage is produced (or input is provided)
Electromagnetic Induction
It is the fundamental operating principle of transformers, inductors, and many types of electrical motors, generators and solenoids.
Faraday (1831):
An emf is induced in a conductor if a magnetic field passes by a conductor
Whenever in a conductor if change in current occurs it "induces”a voltage (electromotive force) in both the conductor itself (self-inductance) and in any nearby conductors (mutual inductance).

8. Electromagnetic Induction
Magnitude of induced current can be increased by:
Increasing strength of magnetic field
Increasing speed of relative motion
Positioning of field & conductor to increase number of magnetic lines of flux cut
Magnetic field usually produced by electromagnet

9. How motors work Electricity supplied to stator
Magnetic field generated that moves around rotor
Current induced in rotor
Rotor produces second magnetic field that opposes stator magnetic field
Rotor begins to rotate
Electromagnetics
Stator
Rotor

10. Overview of Direct Current Machines
Direct-current (DC) machines are divided into dc generators and dc motors.
Most DC machines are similar to AC machines: i.e. they have AC voltages and current within them.
DC machines have DC outputs just because they have a mechanism converting AC voltages to DC voltages at their terminals.
This mechanism is called a commutator; therefore, DC machines are also called commutating machines.
DC generators are not as common as they used to be, because direct current, when required, is mainly produced by electronic rectifiers.
While dc motors are widely used, such automobile, aircraft, and portable electronics, in speed control applications…