Chapter 17 Electronic Technology Preview Section 1 Electronic DevicesElectronic Devices Section 2 Communication TechnologyCommunication Technology Section 3 ComputersComputers Concept Mapping

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.

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

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

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

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

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

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

Chapter 17 Section 1 Electronic Devices

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

Chapter 17 Diodes, continued Section 1 Electronic Devices

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

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

Chapter 17 Section 1 Electronic Devices

Chapter 17 Transistors, continued Transistors in Switches Remote–controlled 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

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 don’t last as long. Section 1 Electronic Devices

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.

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

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

Chapter 17 Communicating with Signals, continued Section 2 Communication Technology

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

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

Chapter 17 Analog Signals, continued The image below explains how a phone works. Section 2 Communication Technology

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

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

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

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

Chapter 17 Digital Signals, continued Playing a CD The image below explains how a CD player works to produce sound. Section 2 Communication Technology

Chapter 17 Comparing Digital and Analog Signals Click below to watch the Visual Concept. Visual Concept Section 2 Communication Technology

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

Chapter 17 Section 2 Communication Technology

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

Chapter 17 Section 2 Communication Technology

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

Chapter 17 Radio and Television, continued Section 2 Communication Technology

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.

Chapter 17 Objectives List a computer’s 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

Chapter 17 Objectives, continued Describe what computer software allows a computer to do. Describe computer networks. Section 3 Computers

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

Chapter 17 What Is a Computer?, continued The image below shows an example of a computer’s functions. Section 3 Computers

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 computer’s instructions. Section 3 Computers

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

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

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

Chapter 17 Computer Hardware, continued Output Devices show the results of a computer’s 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

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

Chapter 17 Compact Discs, continued Section 3 Computers

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

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

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

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

Chapter 17 Electronic Technology Use the terms below to complete the concept map on the next slide. amplifiertransistors switchdoping semiconductorelectrons Concept Mapping

Chapter 17 Electronic Technology

Chapter 17 Electronic Technology