Transcript Magnetism 5 Transformers/Generators

Magnetism 5
Transformers & Generators
Transformer
Device in which alternating current in one coil of
wire induces a current in a second wire.
Primary coil (input) is connected to a source of
Alternating _______
current
___________
This induces a current in the
Secondary
coil
___________
_____(output)__
Step-up Transformer
• Increases Output Voltage
• Has more turns of wire in
the second coil
• More turns of coil =
higher Voltage
• Power companies use
them to send electricity
over long distances
• Examples: neon sign or
plug for CD player
Step-down Transformer
• Decreases output
voltage
• Fewer turns of wire in
second coil
• Fewer turns of wire =
lower voltage
• Power to individual
homes
Generator
Device that changes mechanical energy into
electrical energy.
• It has the ability to induce
a current.
•Electricity usually comes
from generators.
How it works
•A loop of wire spins through a magnetic field.
_____________________________________
•Moving magnets make electricity.
_____________________________________
Motor
Device that changes electrical energy into
mechanical energy
•It has the ability to reverse poles of an electromagnet
•Has electromagnet & permanent magnet
•How it works•the electromagnet is free to turn in
the middle of permanent magnets.
•Changing + & - in the
electromagnet changes the
attraction or repulsion towards the
permanent magnet.
Turbine
Turbine – an engine that….
removes energy from a fluid or air flow and
converts it into useful work.
Steam Turbine – is used for the……
generation of electricity in thermal power
plants, such as plants using coal or fuel oil or
nuclear power.
Almost all electrical
power on Earth is
produced with a turbine
of some type.
How mechanical energy is
transformed into electricity.
Mechanical Energy (moving water) spins
the turbine. The spinning turbine spins
magnets in the generator. Coils of wire
surrounding the spinning magnets cut
through the magnetic field which induces
a current. The current made by the
generator goes to the power lines. Power
lines bring the electricity to your homes,
schools etc.