IT-101 Section 001. Introduction to Information Technology. Lecture #2. Overview. Chapter 1: The Information age Information, messages and signals Information systems Analog and digital information Chapter 3: Representing information in binary form. The Information Age.
Introduction to Information Technology
Source:The Economist, Sept. 23, 2000
Yes, Mr. Faraday would like to meet you at 4:00 p.m. today
Sure, I’ll be there!
Source: telecom glossary (http://atis.org)
A diaphragm, which vibrates when sound waves are impinged on it, is connected to a stylus which can cut grooves in a solid material such as tin foil, wax, or vinyl. As the stylus is moved over the material, the vibration from the diaphragm produces a groove whose depth is proportional to the sound intensity
To play back, the stylus travels over the grooves of the recording, which vibrates the diaphragm and produces soundThe Phonograph
Exercise: Identify the above components for the phonograph and telephone system.
Useful article for understanding difference between analog and digital: http://cgi.sacbee.com/ib/tech/wiredlife/20010621.html
Human speech is an example of analog communication.
Speech causes air to vibrate with varying amplitude (volume) and frequency (pitch).
This continuous acoustical waveform can be detected by a microphone and converted into an analogous electrical waveform for transmission over a circuit.
If an analog signal provides such a close representation of information sources, why do we use digital?
Regenerated Digital Signal