Transformer , induction motor, Photovoltaic solar cell , piezoelectric effect and alternator

1. Instrumentation and Control
TRANSFORMER , INDUCTION MOTOR, PHOTOVOLTAIC SOLAR CELL , PIEZOELECTRIC
EFFECT AND ALTERNATOR

2. Transformer
 A transformer is a static piece of apparatus by
means of which an electrical power is
transferred from one alternating current circuit
to another electrical circuit.
 There is no electrical contact between them
 The desire change in voltage or current without
any change in frequency
 Symbolically the transformer denoted as.

3. Working principles of transformer
 The transformer works in the principle of mutual induction
 When the alternating current flows in the primary coils, a changing
magnetic flux is generated around the primary coil.
 The changing magnetic flux is transferred to the secondary coil through
the iron core.
 The changing magnetic flux is cut by the secondary coil, hence
induces an e.m.f in the secondary coil

4. Induction Motor
 An induction motor works on
transforming action.
 The stator works as the primary while
the rotor works as the secondary.
 It is also called asynchronous motor
 It consists of two parts:
1. Stator - It is the stationary part of the
motor.
2. Rotor - It is the rotating part of the
motor.

5. Photovoltaic Solar Cell
• A structure that converts solar energy directly to
DC electric energy.
– It supplies a voltage and a current to a resistive load
(light, battery, motor).
• It is like a battery because it supplies DC power.
• It is different from a battery in the sense that the
voltage supplied by the cell changes with changes
in the resistance of the load.

6. Piezoelectric Effect
The positive & negative charges are symmetrically distributed in a crystal.
Piezoelectric ceramic materials are not piezoelectric until the random
ferroelectric domains are aligned by a process known as POLING.
Poling consists of inducing a DC voltage across the material.
The principle of converting energy by applying pressure to a crystal.
When an electric voltage is applied to a transducer crystal, the crystal
gets excited and is deformed.

7. Alternator
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.
For understanding working of alternator let's
think about a single rectangular turn placed in
between two opposite magnetic pole as shown
figure.