The document describes the design and working of an AC generator. It includes: - The main components of an AC generator are the stator, which has copper coil windings, and the rotor, which has magnets and spins inside the stator. - Electromagnetic induction causes an alternating current to be generated in the stator coils as the rotor's magnetic field cuts across them during rotation. - The document provides step-by-step instructions to construct a simple AC generator using readily available materials like copper wire, magnets, pipes, and wood. It also includes diagrams of the circuit and internal components.

2. Electrical Engineering Department
CECOS University of I.T & Emerging Sciences Hayatabad, Peshawar
AC Generator
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PREPARED BY :
JALAL AHMED CU-322-2017(A)
Group members:
M.TAHA CU-332-2017(A)
SYED AQEEEL CU-344-2017(A)
AMIR USMAN CU-286-2017(A)
SUBMITTED TO:
ENGR. ALI MUJTABA DURRANI

3. Introduction:
AC Generator Definition:
AC Generator is a device which converts mechanical energy into electrical
energy by using electromagnetic induction and emf. It focuses on the working
principles and components used in it. The interchange of different energies and
electricity generation by the process of induction can be completely explained
by AC generator.
Point to explain
Electromagnetic induction
The phenomena of producing induced emf and emf induced Current due to
change of magnetic flux is called Electromagnetic induction.
EMF
Total work done per unit charge in known as emf
AC Generator

4. THEORY OF AC Generator:
 Each time the rotor makes one complete revolution, one complete cycle
of AC is developed.
 A generator has many turns of wire wound into the slots of the rotor.
 The magnitude of AC voltage generated by an AC generator is
dependent on the field strength and speed of the rotor.
 Most generators are operated at a constant speed; therefore, the
generated voltage depends on field strength.

5. AC Generator Parts:
 The Stator:
The stator is made of 2.5 inch long 10 iron strips joint together with paper
tape and have copper winding on it.
Copper coil winding
 The Rotor:
Rotor is made by using a piece of pipe, 4 magnets and iron nail.
AC (Alternating current) Generator Rotor side view

6. AC Generator Steps of Construction
 Making of Coil
i. Measure 2 ½ inch of iron strip and cut 10 equal parts of it.
ii. Firmly hold and pile all parts together using paper tape in a way that there should be no
space between strips. Wound approximately 300 turns of copper wire around the core.
iii. We need two such coils to make an AC generator.
 Making of Rotor
i. Take half inch diameter pipe and cut a piece of 2 ½ inches
ii. Stick 4 bar magnets on the piece of pipe with the help of super glue
iii. Make sure the same pole of magnets must be in alternative manner. It will be in the order
of North-South-North-South.
iv. Check out the poles of magnets if they are aligned right by using another magnet.
v. Take long iron nail of 6 inch.

7.  Body of the Generator
i. Take wooden piece and two pieces of pipes (one is of 2" and the other is
should be of 1").
ii. Fix the both pipes and check if it is perfectly leveled.
iii. Stick the pipes on the wooden base with the help of super glue.
iv. Cut 2 pieces of pipes measuring half inch.
v. Join the pieces perpendicular to the axle (one at each side) at the base.
vi. Fix coil on each of the pipe.
vii. Burn the coating of coils at the terminals using lighter.
 Testing
i. Join the LED with the coil and rotate the nail, the LED will glow.
ii. If both the coils are connected in series then LED will glow brighter.

8. Block Diagram of AC Generator :
AC (Alternating current) Generator Rotor
front view
AC (Alternating current) Generator Rotor
side view

9. CIRCUIT DIAGRAM OF AC Generator:

10. COMPONENTS REQUIRED:
For construction of Electric Generator you need following things and tools.
a) Super Glue
b) Paper Tape
c) Iron Strips 2
d) Pipe
e) 6" long Iron Nail
f) LED's
g) Copper Wire 30 to 34 gauge
h) 4 Magnets
i) wooden Piece
j) Tools:
k) Iron saw
l) Drill Machine
m) Screwdriver
n) pliers

11. WORKING OF AC Generator:
The working principle of alternator is very simple. It is just like basic
principle of DC generator. It also depends upon Faraday's law of
electromagnetic induction which says the current is induced in the
conductor inside a magnetic field when there is a relative motion
between that conductor and the magnetic field.

12. LOSS OF AC Generator:
 Internal Voltage Drop
The load current flows through the armature in all AC generators. The armature has
some amount of resistance and inductive reactance.
 Hysteresis Losses
Hysteresis losses occur when iron cores in an AC generator are subject to effects from a
magnetic field.
 Mechanical Losses
Rotational or mechanical losses can be caused by bearing friction, brush friction on the
commutate due to armature rotation.

13. Result & Calculation of project :
 Efficiency OF AC Generator:
 Efficiency of an AC generator is the ratio of the useful
power output to the total power input.
 Because any mechanical process experiences some losses,
no AC generators can be 100 percent efficient.
 Efficiency of an AC generator can be calculated using
Equation.
Efficiency =(Output /Input )x 100

14.  Given a 1 motor acting as the prime mover of a generator that
has a load demand of 0.5 kW, what is the efficiency of the
generator?
 Solution:
 Input Power = 700 Watt
 Output Power = 450 Watt
 Efficiency =(output/input)x100= (450W /700)
 0.643 x 100
 64.3%

15. The cylindrical rotor alternators are generally designed for 2-pole
type giving very high speed of
Ns = (120 × f)/P
Ns= (120 × 50) / 2
Ns = 3000 rpm.
Or 4-pole type running at a speed of
Ns = (120 × f) / P
Ns = (120 × 50) / 4
Ns = 1500rpm.
Where f is the frequency of 50 Hz.

16. DEMONSTRATION OF AC Generator: