Electrical Gadgets - Laney baker, Cidney baker (ready to read books txt) 📗

POWERED UP

 A SOURCE OF POWER

Large machines,such as TV,use elecricity from household eletrcity.This electrcity is generated at power plants and sents to our homes from powerlines.Many smaller gadgets,such as remote controls,are powered by batteries.Battries contain chemicles that produce eletrcity.Battries have to be replaced if or recharged when they run down.

MAKING ELECTRICITY WORK

The technology behide most gadgets use elecricity components,such as switches and resistors.This book looks at some of these components and how they work in gadgets,such as touchscreens,game conseles,and battries.The project pages will show you how to make your own gadgets,such as a fan and a circuit game.

PLUG POWER

HOW DOES IT WORK?

The power supply found in our homes is generated in powerplants.Electricity at high voltge lower for us to use saftly in our homes.Gadgets,such as microwaves and TV,need to be plugged into socket using a cord that ends in a plug.The socket is attached to a network of wires that carry the elecricity from a substation.

TRY IT !

Go into each room of your home and find the sockets.How many gadgets do you have permanently plugged in? How many of these gadgets do you use every day?

POWER IN ACTION

While TVs,computers,and game conseles run off in household power,we can plug addition devices into them.These devices use power from the original gadgets supply.

PORTABLE POWER

HOW DOES IT WORK?

Batteries provied small amounts of elecricity when it is connected to a circuit.However,that circuit does not last forever and need to be replaced when they go flat.

BATTERIES IN ACTION

Some gadgets,such as remote controlled toys,need more elecricity then one battery can perviode so they use two more or more batteries.Devices that use a  lot of elecricity such as laptop,computeres,often use  rechargeable batteries,which are more environmentally friendly.

SMART CIRCUITS

HOW DOES IT WORK?

A simple circuite carries elecricity from the power source,such as the battery to the gadget and back to the power source.When the circuite is broken,the elecricity current stops.When you press a touchscreen,you push together two thin layers in the surface of the screen,compleating a circuit.This tells a computer where on the screen you have touched.

CIRCUITS IN ACTION

Some circuits, such as the one that connects a wall socket to the power plant,may be many miles long.Other circuits,such as those found on a circuit board,are a fraction of an inch across. A circuit board may contain hundreds of interconnected circuits.

SWITCHING IT ON

HOW DOES IT WORK?

The simplest switches turn an electrical current on or off.When the switch is in the"on" position,the circuit is compleat and the current and flow.When switch is turned "off"there is a gap in the circuit and the current stops.In more complicated gadgets,switches are used to the change the path the current takes.For instence,a microchip may have millions of switches on it,so that electricity can flow along different paths.

SWITCHES IN ACTION

Different gadgets use vavorious types of switch.Most have a simple on/off switch,while others,such as a food processor,have switches that change the speed of movement.The switch controls the amount of power that turns the gadget's motor.The more power,the faster the motor turns

RESISTING THE FLOW

HOW DOES IT WORK

As it's name suggests,a resistor resites th flow of elecricity though a gadget.The higher the resistence,the smaller the current to flow through.Each gadget needs a particuler current and flow through it to work proplery.It has a resistor of the just right strength to produce the correct current.

RESISTORS IN ACTION

The flow of electricity through a gadget can be precisely controlled using combinations of residtors.Variable the change the current in volume or brightness controls on gadgets such as TVsor MP3 players.

LIGHTING IT UP

HOW DOES IT WORK

Light emitting diodes act like tiny light bulbs.They are found in all kinds of devices:they form the display on digital clocks,transmit information from remote controls,light up watches,and tell you when your gadgets are turned on.Unlike incandescent bulb's,they do not have a filament that will burn out and they do not get especially not hot.Instead,LEDs contain semiconductors,which produce light when elecricity passes through them.

LIGHTS IN ACTION

The face of some alarm clocks,digital radios,and DVD players use led to light them.In gadgets such as e-book readers and TV'S LED's are used to light up there screens

MOTORS AND GENERATORS

HOW DOES IT WORK

Electric motors use combination of electricity and a magnet to make a turing motion.When current flows through a wire that surrounds an iron core,it makes the wire act like a magnet.This temory magnet pushes and pulls againest a perment magnet placed near the wire,and creates a turning motion.

MOTORS AND GENERATORS IN ACTION

Electric motors are found in all kinds of gadgets,from huge motors in cranes to tiny ones inside computers.Powerplantrs use generrators are found in windup gadgets

STATIC ELECTRICITY

HOW DOES IT WORK

For electricity to move between two points,each point needs to have an electrical charged.One point is positively charged ,the other one is negatively charged.The 2 charged pionts are attracted to each other.Inside a photocopier,a drum each other covered in a patteren of postivety charged toner rolls over a piece of negatively charged paper.The toner sticks to the paper as opposite charges attract.

STATIC ELECTRICITY IN ACTION

During a lighting strike,enough electricity passes from the cloud to the ground to power a small town for a year!Tiny amounts of stactic electricity can biuld up in the clothes  an a clothes dryer,making them crackle when you put them on.