Chapter 17 Section 1 Electronic Devices Bellringer Define the
word technology. Can you think of three ways that technology
affects you? Write your answers in your science journal.
Slide 3
Chapter 17 Objectives Identify the role of a circuit board in
an electronic device. Describe semiconductors and how their
conductivity can change. Describe diodes and how they are used in
circuits. Section 1 Electronic Devices
Slide 4
Chapter 17 Objectives, continued Describe transistors and how
they are used in circuits. Explain how integrated circuits have
influenced electronic technology. Section 1 Electronic Devices
Slide 5
Chapter 17 Inside an Electronic Device A circuit board is a
sheet of insulating material that carries circuit elements and that
is inserted in an electronic device. Sending Information to Your
Television When you push a button on your remote control, you send
a signal to the circuit board. The components of the circuit board
process the signal to send the correct information to the
television. Section 1 Electronic Devices
Slide 6
Chapter 17 Semiconductors A semiconductor is an element or
compound that conducts electric current better than an insulator
does but not as well as a conductor does. Semiconductors have
allowed people to make incredible advances in electronic
technology. Section 1 Electronic Devices
Slide 7
Chapter 17 Semiconductors, continued How do semiconductors
work? The way a semiconductor conducts electric current is based on
how its electrons are arranges. Silicon, Si, is a widely used
semiconductor because its conductivity can be changed. Section 1
Electronic Devices
Slide 8
Chapter 17 Semiconductors, continued Doping is the addition of
an impurity element to an semiconductor. Adding the impurity
changes the arrangement of electrons. Section 1 Electronic
Devices
Slide 9
Chapter 17 Section 1 Electronic Devices
Slide 10
Chapter 17 Diodes A diode is an electronic device that allows
electric charge to move more easily in one direction than in the
other. The Flow of Electrons in Diodes The next slide shows how a
diode works. Section 1 Electronic Devices
Slide 11
Chapter 17 Diodes, continued Section 1 Electronic Devices
Slide 12
Chapter 17 Diodes, continued Using Diodes to Change AC to DC
Power plants send electrical energy to homes by means of
alternating current (AC). But many things, such as radios, use
direct current (DC). Diodes can help change AC to DC by blocking
current in one direction. Section 1 Electronic Devices
Slide 13
Chapter 17 Transistors A transistor is a semiconductor device
that can amplify current and that is used in amplifiers,
oscillators, and switches. Transistors as Amplifiers A microphone
does not make a current that is large enough to run a loudspeaker.
But a transistor can be used in an amplifier to make a larger
current. The next slide explains how. Section 1 Electronic
Devices
Slide 14
Chapter 17 Section 1 Electronic Devices
Slide 15
Chapter 17 Transistors, continued Transistors in Switches
Remotecontrolled toy cars use transistors in switches. When a
manual switch in a circuit is closed, a small current is made in
the small loop. The small current causes the transistor to close
the large loop. As a result, a larger current is made in the large
loop. The larger current runs the motor. Section 1 Electronic
Devices
Slide 16
Chapter 17 Integrated Circuit An integrated circuit is an
entire circuit that has many components on a single semiconductor.
Many complete circuits can fit into one integrated circuit. So,
complicated electronic systems can be made very small. Before
transistors and semiconductor diodes were made, vacuum tubes were
used. But vacuum tubes are much larger than semiconductor
components are. They also get hotter and dont last as long. Section
1 Electronic Devices
Slide 17
Chapter 17 Section 2 Communication Technology Bellringer The
following is a question in International Morse Code: Decipher the
question and write it in your science journal. Then, write your
answer to the question in International Morse Code.
Slide 18
Chapter 17 Objectives Identify how signals transmit
information. Describe analog signals and their use in telephones
and records. Describe digital signals and their use in compact
discs. Describe how information is transmitted and received in
radios and televisions. Section 2 Communication Technology
Slide 19
Chapter 17 Communicating with Signals The telegraph was one of
the first electronic communication devices. It used an electric
current to send messages in Morse code through wires joining two
places. Morse code has patterns of dots and dashes that stand for
letters and numbers. Section 2 Communication Technology
Slide 20
Chapter 17 Communicating with Signals, continued Section 2
Communication Technology
Slide 21
Chapter 17 Communicating with Signals, continued Signals and
Carriers A signal is anything, such as a movement, sound, or a set
of numbers and letters, that can be used to send information. Often
one signal is sent using another signal called a carrier. Electric
current is often used as a carrier. Section 2 Communication
Technology
Slide 22
Chapter 17 Analog Signals An analog signal is a signal whose
properties change without a break or jump between values. Talking
on the Phone When you talk into the transmitter of a phone, the
sound waves made when you speak are changed into an analog signal.
The receiver on a phone changes the analog signal back into a sound
wave. Section 2 Communication Technology
Slide 23
Chapter 17 Analog Signals, continued The image below explains
how a phone works. Section 2 Communication Technology
Slide 24
Chapter 17 Analog Signals, continued Analog Recording Early
recordings of sound were stored as analog signals by making grooves
in wax or metal. Playing a Record When a record is played, a stylus
makes an electromagnet vibrate. The electromagnet induces an
electric current that is used to make sound. Section 2
Communication Technology
Slide 25
Chapter 17 Digital Signals A digital signal is a signal that is
represented as a sequence of separate values. Information in a
digital signal is represented as binary numbers. Numbers in binary
are made up of only two digits, 1 and 0. Section 2 Communication
Technology
Slide 26
Chapter 17 Digital Signals, continued Digital Storage on a CD
Sound is recorded to a compact disc (CD) by means of a digital
signal. The figure below shows the surface of a CD. Pits stand for
1s and lands stand for 0s. Pits and lands store information that
can be converted into sound. Section 2 Communication
Technology
Slide 27
Chapter 17 Digital Signals, continued Digital Recording In a
digital recording, a sound wave is measured many times each second.
From these measurements, numbers are generated that represent the
sound wave. These numbers are then changed to binary values using
1s and 0s. The 1s and 0s are stored as pits and lands on a CD.
Section 2 Communication Technology
Slide 28
Chapter 17 Digital Signals, continued Playing a CD The image
below explains how a CD player works to produce sound. Section 2
Communication Technology
Slide 29
Chapter 17 Comparing Digital and Analog Signals Click below to
watch the Visual Concept. Visual Concept Section 2 Communication
Technology
Slide 30
Chapter 17 Radio and Television Radio Radio stations use radio
waves to carry signals that represent sound. Radio waves are
transmitted by a radio tower. They travel through the air and are
picked up by a radio antenna. The next slide explains how a radio
works. Section 2 Communication Technology
Slide 31
Chapter 17 Section 2 Communication Technology
Slide 32
Chapter 17 Radio and Television, continued Television Video and
audio signals can be sent as analog or digital signals to your
television. The signals can be sent through cables or from
satellites or broadcast towers. You can watch digital television
shows on an analog TV. However, the sound and images of the shows
are clearer if watched on a digital TV. Section 2 Communication
Technology
Slide 33
Chapter 17 Section 2 Communication Technology
Slide 34
Chapter 17 Radio and Television, continued Plasma Displays are
a new kind of television screen. These displays can be as thin as
15 cm. Plasma displays have thousands of tiny cells with gases in
them. A computer makes a current in the gases. The current
generates colored lights, which make a picture on the screen. The
image on the next slide explains how plasma displays work. Section
2 Communication Technology
Slide 35
Chapter 17 Radio and Television, continued Section 2
Communication Technology
Slide 36
Chapter 17 Section 3 Computers Bellringer A computer is an
electronic device that performs tasks by following instructions
given to it. List all of the ways that you use a computer in your
daily life. Write your list in your science journal.
Slide 37
Chapter 17 Objectives List a computers basic functions, and
describe its development. Identify the main components of computer
hardware. Explain how information can be stored on CD-Rs and
CD-RWs. Section 3 Computers
Slide 38
Chapter 17 Objectives, continued Describe what computer
software allows a computer to do. Describe computer networks.
Section 3 Computers
Slide 39
Chapter 17 What Is a Computer? A computer is an electronic
device that performs tasks by following instructions given to it.
Basic Functions The information you give to a computer is called
input. The computer processes the input. The computer stores
information in its memory. Output is the final result of the job
done by the computer. Section 3 Computers
Slide 40
Chapter 17 What Is a Computer?, continued The image below shows
an example of a computers functions. Section 3 Computers
Slide 41
Chapter 17 What Is a Computer?, continued The First Computers
The first computers were made up of large pieces of equipment that
could fill a room. The first general-purpose computer was ENIAC.
Modern Computers are much smaller because they use microprocessors.
A microprocessor is a single chip that controls and carries out a
computers instructions. Section 3 Computers
Slide 42
Chapter 17 Computer Hardware Hardware is the parts or pieces of
equipment that make up a computer. The images below show several
types of hardware. Section 3 Computers
Slide 43
Chapter 17 Computer Hardware, continued Input Devices give
information, or input, to the computer. Common input devices are a
keyboard, a mouse, and a scanner. Central Processing Unit (CPU) is
where a computer does tasks. In the CPU, the computer does
calculations, solves problems, and carries out instructions given
to it. Section 3 Computers
Slide 44
Chapter 17 Computer Hardware, continued Memory is where
information can be stored. Kinds of memory are hard disks, CDs,
read-only memory (ROM) and random-access memory (RAM). ROM is
permanent. It handles jobs such as start-up, maintenance, and
hardware management. RAM is temporary. RAM stores information only
while it is being used. Section 3 Computers
Slide 45
Chapter 17 Computer Hardware, continued Output Devices show the
results of a computers job. Monitors, printers, and speakers are
output devices. Modems and Interface Cards allow computers to
exchange information. Modems send information through telephone
lines and interface cards use cables or wireless connections.
Section 3 Computers
Slide 46
Chapter 17 Compact Discs Burning and Erasing CDs One kind of CD
that you can put information onto, or burn, is a CD-recordable
(CD-R) disc. You can burn a CD-R disc only once. A CD-rewritable
(CD-RW) disc can be used more than once. The next slide explains
the difference between CD-R and CD-RW discs. Section 3
Computers
Slide 47
Chapter 17 Compact Discs, continued Section 3 Computers
Slide 48
Chapter 17 Computer Software Software is a set of instructions
or commands that tells a computer what to do. Kinds of Software
Operating-system software handles basic operations needed by the
computer. Application software tells the computer to run a utility.
Word processors, video games, and graphics programs are examples of
application software. Section 3 Computers
Slide 49
Chapter 17 Computer Networks The Internet is a huge computer
network made up of millions of computers that can all share
information. Home computers can connect to the Internet by
connecting to an Internet Service Provider (ISP). Computers in a
school or business can be joined in a Local Area Network (LAN).
These computers connect to an ISP through only one line. Section 3
Computers
Slide 50
Chapter 17 Computer Networks, continued ISPs allow computers in
your home or school to connect to large routing computers that are
linked around the world. Section 3 Computers
Slide 51
Chapter 17 Computer Networks, continued The World Wide Web When
you use a Web browser to look at pages on the Internet, you are on
the World Wide Web. Web pages share a format that is simple enough
that any computer can view them. They are group into Web sites.
Clicking on a link takes you from one page or site to another.
Section 3 Computers
Slide 52
Chapter 17 Electronic Technology Use the terms below to
complete the concept map on the next slide. amplifiertransistors
switchdoping semiconductorelectrons Concept Mapping