Communication Technology

Telephone• There is not much difference between the way a string

telephone and a real telephone work except that electric current replaces the vibrating string in a telephone.

• In an old-style telephone, the person speaking vibrated a metal diaphragm.

• The diaphragm’s vibrations rapidly compressed and uncompressed carbon granules, changing their resistance.

• A current passing through the granules was increased or decreased by the changing resistance.

• At the other end, the rapidly changing current ran through a speaker and caused its diaphragm to vibrate back and forth, so the second person heard the first person speaking.

IPOF in Communication• Information and communication systems include

the inputs, processes, and outputs associated with sending and receiving information.

• Almost any information can be transformed into electrical signals.

• A weak electrical signal can be used to shape a stronger one, which can control c. other signals of light, sound, mechanical devices, and radio waves

• The quality of communication is determined by the strength of the signal in relation d. to the noise that tends to obscure it.

Facts

• Communication errors can be reduced by boosting and focusing signals, shielding the signal from internal and external noise, and repeating information, but all of these increase cost.

• Digital coding of information (using only 1s and 0s) makes possible more reliable transmission of information.

• As technologies that provide privacy in communication improve, so do those for invading it.

IPOF examples of communication technology.

• [Example: An electric guitar, amplifier, and speakers take a mechanical input (sound waves from the vibrating strings), process it (convert it to an electrical signal), transmit the electrical signal to an amplifier that increases the electrical signal and sends it on to a speaker system that converts the electrical signal back into a mechanical output (sound).]

Technology Transfer

• Information and communication systems allow information to be transferred from human to human, human to machine, and machine to machine.

Parts of a communication system includes the:

• Source• Encoder• Transmitter• Receiver • Decoder• Destination

Analysis of a communication system (GPS)

GPS

• Statement of need (What is the system supposed to do?)

• Major components (What are the subsystems?)• Basic system design (How are the components

or subsystems connected and how do they interact?)

• Controls (What are the mechanisms that use information to cause the system to change?)

Function Analysis GPS Continued

• Engineering resources employed (Mechanical, Electrical, Electronic, Structural, etc.)

• System performance evaluation (What processes are used to determine system performance?)

• Social, cultural, economic, and political impacts (How does the technology affect peoples’ lives?)

• Environmental impact (How does the technology affect the environment?)

Extension Assignment

• Students will research and report on the design of a communication system.

• You will pick from a list provided on the extension sheet.