The document is a seminar presentation about alternators, highlighting their function in automotive charging systems alongside batteries and voltage regulators. It explains the mechanics, components, and diagnostics of alternators while contrasting them with older generator systems. Additionally, it covers the importance of correct voltage regulation and common issues like bearing failure that can affect alternator performance.

1. BASIC ELECTRICAL
ENGINEERING
Course seminar on;

2. ….What you've just experienced is an example of an alternator breathing
its last breath.
Your first thought might have been the battery is dying. In a sense, you
would be right because the battery and the alternator are related, but the
battery tends to get all the press.
This presentation aims to explain the mechanics of alternators, how you
can diagnose problems and what you can do if you have a bad alternator.
You will come to now to some background information about alternators
and the war of the currents.

3. An automotive charging system is made up of three major
components: the battery, the voltage regulator and an
alternator.
The alternator works with the battery to generate power for
the electrical components of a vehicle, like the interior and
exterior lights, and the instrument panel. An alternator gets
its name from the term alternating current (AC)

4. Alternators produce AC power through electromagnetism formed
through the stator and rotor
The electricity is channeled into the battery, providing voltage to run
the various electrical systems.
Most cars today have a serpentine belt, or one belt that drives all
components that rely on crankshaft power. Most alternators are mounted
using brackets that bolt to a specific point on the engine. One of the
brackets is usually a fixed point, while the other is adjustable to tighten
the drive belt.
Alternators are typically found near the front of the engine and are
driven by the crankshaft, which converts the pistons' up-and-down
movement into circular movement.

5. IG

6. ALTERNATOR COMPONENTS
On the back side of the alternator you'll find several
terminals (or connecting points in an electrical circuit). Let's
take a look at those:
S terminal - Senses battery voltage
IG terminal - Ignition switch that turns the voltage
regulator on
L terminal - Closes the circuit to the warning lamp
B terminal - Main alternator output terminal (connected to
the battery)
F terminal - Full-field bypass for regulator

7. ALTERNATOR COMPONENTS

8. As we start to disassemble the alternator, we find :
1. The diode rectifier: The regulator distributes the power the alternator
creates, and it controls the output of power to the battery
2. The voltage regulator: The rectifier bridge converts the power
3 .Slip rings
both help to conduct current to the rotor field winding,
4. Brushes:
5. The alternator reveals a large cylinder with triangular finger poles around
the circumference. This is the rotor

10. •The rotor spins inside the stator.
• The rotor assembly fits inside
the stator with tolerance between
the two, so the rotor can spin at
high speeds without striking the
stator wall.
•On each end of the shaft sits a
brush and a slip ring.

11. In the early days, cars used generators rather than alternators
to power the vehicle's electrical system and charge the battery
Generators produce direct current, which travels in one
direction, as opposed to the alternating current for the
electricity in our houses, which periodically reverses directions.
Alternating current became more attractive as it generates
higher voltage more efficiently, But car batteries can't use AC
power since they produce DC power.
As a result, the alternator's power output is fed through
diodes, which convert the AC power to DC power.

12. The rotor and the stator are the two components that generate
power.
As the engine rotates the alternator pulley, This is referred to
as a three-phase current.
This AC current is fed through stator leads into a connecting
set of diodes. Two diodes connect to each stator lead to
regulate the current.
The diodes are used to essentially block and direct the
current.
Since batteries need DC current, the diodes become a one-
way valve that will only allow current to pass in the same
direction.

13. THE TWO BASIC STATOR WINDING DESIGNS
DELTA WOUND WYE STYLE
Delta wound are easily
identifiable by their shape,
as they're triangular
These windings allow for a
high current flow at lower
RPM
Wye windings resemble
the flux capacitor
These windings are ideal
for diesel engines, as they
produce higher voltage
than delta stators at even
lower RPM.

15. The resulting voltage is ready to use in the battery.
Too much or too little voltage can damage the battery,
as well as other electrical components
To ensure the correct amount, a voltage regulator
determines when and how much voltage is needed in
the battery.
One of two types of regulators are found in most
alternators: The grounded regulator works by
controlling the amount of negative or battery ground
going into the winding in the rotor, while a grounded
field type works vice versa

16. THE LIFE AND DEATH OF AN ALTERNATOR
Bearing failure: The needle bearings that allow
the rotor to spin freely inside the stator can break
down from dirt and heat
When the bearings fail, the rotor will not
spin efficiently and can eventually seize.
Usually an alternator with bearings failure
makes a loud grinding noise

17. Stator windings : Test whether your car had an issue
with one of its stator windings, you'd need to use a
voltmeter to check the voltage . This is called a load test
If you have a failing alternator, the voltage will be well
below 14 volts. If so, it's time to replace the alternator.
Serpentine belt : If the belt is worn or loose, the
alternator won't function properly. A bad belt is easy to
replace

18. Voltmeterbearings
Serpentine belt
Alternator stator

19. ALTERNATOR S ,THE POWER SUPPLIER
Alternators are less expensive than say, a power
steering pump or air conditioner compressor
Batteries can only be recharged so many times
before they'll lose their ability to hold a charge
A bad alternator will ruin a good battery if you
don't address it quickly.
High-output alternators have become popular
with custom car shops and in high-performance
cars.
Some custom shops are even installing dual-
alternator systems to handle the additional

20. Presented by,
VedavyasP. Burli