A transformer transfers electrical energy between two circuits through electromagnetic induction. It works by using a primary coil to produce a varying magnetic field that induces a voltage in a secondary coil. This allows transformers to increase or decrease voltage levels in an electrical circuit. The number of turns in each coil and the ratio of their turns determines the relationship between the voltages in the primary and secondary circuits. Transformers are commonly used to increase voltage for power transmission over long distances and decrease voltage for safe use in electronic devices.
2. History
A varying current in the
first or primary winding
creates a varying magnetic
flux in the transformer's
core and thus a
varying magnetic
field through
the secondary winding.
3. This varying magnetic
field induces a
varying electromotive force
(EMF), or "voltage", in the
secondary winding. This effect is
called inductive coupling.
4. A transformer is a device that transfers
electrical energy from one circuit to
another through inductively coupled
conductors the transformer's coils.
5. How it is used?
A transformer is used to bring
voltage up or down in an AC
electrical circuit. A transformer
can be used to convert AC power
to DC power.
8. William Stanley, Jr. (USA)
•He contributed to
the development of
an alternating
current induction
motor.
9. Lucien Gaulard (France)
(1850 - November 26,
1888) invented devices
for the transmission
of alternating
current electrical
energy.
10. Sebastian Ziani de Ferranti (England)
who promoted the
installation of large
electrical generating
stations and alternating-
current distribution
networks in England.
12. Principles
transformer is based on two principles:
(1) that an electric current can produce a
magnetic field ( electromagnetism)
(2) that a changing magnetic field within a
coil of coil induces a voltage across the
ends of the coil
( electromagnetic induction)
17. Step Down Transformer
If we assume
there is no loss
of power,
Out put power
= Input power
EsIs = EpIp = K
18. If a load is connected to the secondary winding,
current will flow in this winding, and electrical
energy will be transferred from the primary circuit
through the transformer to the load. In an ideal
transformer, the induced voltage in the secondary
winding (Vs) is in proportion to the primary voltage
(Vp) and is given by the ratio of the number of turns
in the secondary (Ns) to the number of turns in the
primary (Np) as follows:
19. The transformer
equation:
N1 = V1
N2 = V1
N1 = Number of turns on coil 1
N2 = Number of turns on coil 2
V1 = Voltage on coil 1
V2 = Voltage on coil 2
20. Advantage of Alternative Current
Electric power distribution primarily used
direct current at the same voltage used by
motors and lights.
Changing direct current voltage level
required rotating machinery which was
costly to purchased and install.
22. BASIC TRANSFORMER
The basic transformer is an electrical device
that transfers alternating-current energy
from one circuit to another circuit by
magnetic coupling of the primary and
secondary windings of the transformer.
23. The voltage applied to the primary winding causes current to
flow in the primary.
This current generates a magnetic field, generating a counter
emf (cemf) which has the opposite phase to that of the applied
voltage. The magnetic field generated by the current in the
primary also cuts the secondary winding and induces a voltage
in this winding.
24. TRANSFORMER CONSTRUCTION
A TRANSFORMER consists of two coils
of insulated wire wound on a core. The
primary winding is usually wound
onto a form, then wrapped with an
insulating material such as paper or
cloth.
26. Transformer Constructions
The most common types of
transformers are the shell-core and
the hollow-core types. The type and
shape of the core is dependent on the
intended use of the transformer and
the voltage applied to the current in
the primary winding.
28. The current causes a magnetic field
to be set up around both the
primary and the secondary
windings. The moving flux causes a
voltage to be induced into the
secondary winding, countering the
effects of the counter emf in the
primary.
29. Power of Transformer
A transformer with two or more windings
wound on a laminated iron core. The
transformer is used to supply stepped up and
stepped down values of voltage to the
various circuits in electrical equipment.
31. Application
The major application of transformer is
to increase voltage before transmitting
electrical energy over long distances
through the wire.
Also used extensively in electronic
products to step down the supply voltage
to a level suitable for the low voltage
circuits they contain.
