How Electric Motors Work
An electric motor works because its insides contain both magnetism and
magnets. An electric motor uses the magnets to
power its motion. Magnets have the ability to
both repel and attract one another. In fact, the
fundamental law of all magnets states that
opposites attract and likes repel. There are two
ends to each magnet: one end is marked "north,"
and the other end is marked "south." The south
end of a magnet is attracted to the north end of
the other magnet and repels against the other
magnet's south end. The same is true for the
north end; it wants to connect to the other
magnet's south end and repels against its north
The main source of power of an electric motor is its electromagnet. The
electromagnet is wrapped around coil and is placed in the middle of the
axle. The axle is a magnet as well. A battery
is attached to the electromagnet, and its ends
repel against the ends of axle causing it to
begin turning. This begins to cause motion,
and the electric motor begins to spin freely,
giving it power.
A basic electric motor contains six different parts: armature, brushes,
commutator, field magnet, axle and power supply. The axle in an electric
motor holds the commutator and the armature. The armature is a set of
electromagnets that cause the motor to work. The armature consists of a
group of thin metal plates stacked on top of each other. A thinly cut copper
wire is coiled around each one, and each end of the copper wire is soldered.
Each of the metal plates is wired to the commutator. The electric field
begins to work in two parts. When the contacts of the commutator attach to
the electromagnet's axle, they begin to the spin magnets. The brushes are
made of springy metal that make a connection with the contacts of the
commutator. The field magnet is placed inside and may include two
additional magnets to work in correlation. The ends of the magnets rest
against the sides and work with the rest of the parts to make the electric
How Generator works
The purpose of a generator is to convert motion into electricity. This wouldn't be possible if it
wasn't for one fact: That a wire passing through a magnetic field causes electrons in that wire to
move together in one direction.
A generator consists of some magnets and a wire (usually a
very long one that's wrapped to form several coils and known
as an armature). A steam engine or some other outside source
of motion moves the wire or armature through the magnetic
field created by the magnets.
In the example to the left, a loop of wire is spinning within a
magnetic field. Because it is always moving through the field,
a current is sustained.
But, because the loop is spinning, it's moving across the field
first in one direction and then in the other, which means that
the flow of electrons keeps changing.
Because the electrons flow first in one direction and in the other, the generator produces
an alternating current.
One advantage that AC has over DC is that it can easily be "stepped up" or "stepped down" with
a transformer. In other words, a transformer can take a low-voltage current and make it a high-
voltage current, and vice versa.
This comes in handy in transmitting electricity over long distances. Since AC travels more
efficiently at high voltages, transformers are used to step up the voltage before the electricity is
sent out, and then other transformers are used to step down the voltage for use in homes and
A loop of wire spinning through a
magnetic field will create an
alternating current. Note: current
will flow only if the circuit connected
to the generator is complete.
An electrical generator is a device that converts mechanical energy to electrical
energy, generally using electromagnetic induction. The source of mechanical energy
may be a reciprocating or turbine steam engine, water falling through a turbine or
waterwheel, an internal combustion engine, a wind turbine, a hand crank, or any
other source of mechanical energy.
The Dynamo was the first electrical generator capable of delivering power for
industry. The dynamo uses electromagnetic principles to convert mechanical
rotation into an alternating electric current. A dynamo machine consists of a
stationary structure which generates a strong magnetic field, and a set of rotating
windings which turn within that field. On
small machines the magnetic field may be
provided by a permanent magnet; larger
machines have the magnetic field created
The energy conversion in generator is
based on the principle of the production of dynamically induced e.m.f. Whenever a
conductor cuts magneticic flux , dynamically induced e.m.f is produced in it
according to Faraday's Laws of Electromagnetic induction.This e.m.f causes a
current to flow if the conductor circuit is closed. Hence, two basic essential parts of
an electrical generator are (i) a magnetic field and (ii) a conductor or conductors
which can so move as to cut the flux.
How Electric Motor Works
Electric motors are everywhere! In your house, almost every
mechanical movement that you see around you is caused by an
AC (alternating current) or DC (direct current) electric motor.
A simple motor has six parts:
Armature or rotor
DC power supply of some sort
By understanding how a motor works you can learn a lot about
magnets, electromagnets and electricity in general. In this article,
you will learn what makes electric motors tick.
Electromagnetic induction (or
sometimes just induction) is a
process where a conductor placed in
a changing magnetic field (or a
conductor moving through a
stationary magnetic field) causes the
production of a voltage across the
conductor. This process of
electromagnetic induction, in turn,
causes an electrical current - it is said to induce the current.
Michael Faraday is given credit for the discovery of
electromagnetic induction in 1831, though some others had noted
similar behavior in the years prior to this. The formal name for
the physics equation that defines the behavior of an induced
electromagnetic field from the magnetic flux (change in a
magnetic field) is Faraday's law of electromagnetic induction.
Hydraulic power plants
In power station require the installation of large equipment such
as water turbines, generators, transformers, and overhead
cranes, as well as piping and electrical construction.
Hydraulic power station uses clean energy to supply electrical
power. We install water
turbines and generators, these
are major equipment in power
stations in both Japan and
overseas. We apply its
capabilities in the construction
of large water pumps as well
as wind turbine.
This shows a 216,000-kW water turbine runner being lifted.
The weight of the water turbine
runner was 180 tons, but there
was no lifting equipment at the
port near the site, so a ship with
a derrick crane was chartered
and transported from Japan.
Thermal Power Plant
In a conventional thermal power station, a
fuel is used to heat water, which gives off
steam at high pressure. This in turn
drives turbines to create electricity.
At the heart of a power stations is a
generator, a rotating machine that
converts mechanical energy into
electrical energy by creating relative
motion between a magnetic field and a conductor. The energy
source harnessed to turn the generator varies widely. It depends
chiefly on which fuels are easily available and on the types of
Thermal power plants are classified by the type of fuel used
Our Lady of Manaoag College
Batchelor of Science in Information Technology
(HEAT, ELESTRICITY, & MAGNITISM)
JUSTINE OCAMPO GARCIA
1st Year S.Y. 2012-2013