3.2 DIGITAL ELECTRONICS 53 ANALOGUE VS DIGITAL The values 0 and 1 are the basis of the binary code, which is the system allowing data processing in computers and other electronic devices. Analogue and digital The two main fields of application of electronics are analogue and digital electronics; all information which goes through an electronic system is, in fact, either in analogue or in digital form. To understand the difference between the two, we may think of how an analogue and a digital instrument, for example a thermometer, works: A device combining analogue and digital systems is the car, for example. Speed is an analogue value, but it is converted into a digital one so that the car computer can monitor it. an analogue thermometer represents the temperature variation with a liquid into its glass tube moving along a graded scale: the representation is analogue , or similar, to the phenomenon it measures; other analogue devices have pointers that move around dials to show measurements; ONLINE RESOURCES a digital thermometer shows the temperature in the form of numbers, or digits, that show the value of the measurement . Some systems deal with both analogue and digital signals: an example of these is the loudspeaker. The sound which enters the loudspeaker to be amplified is an analogue signal. In order to amplify it, the loudspeaker converts the analogue signal into a digital one, which is filtered, stored and processed, giving an output which is then converted back into another analogue signal. As all signals in real life are analogue, it is necessary to transform digital signals into analogue ones, because in this form they can be caught and understood by users. Signals Analogue signals vary continuously in time, while digital signals vary in a discrete way between two defined levels, 0 and 1, which represent respectively the absence of signal and its maximum level . Advantages of digital electronics Analogue and digital electronics are two complementary sciences and, sometimes, in practical applications, work together . However, digital electronics offers more advantages: What other devices can be found both in analogue and digital form? Main elds of computing dial: quadrante digit: cifra faithfully: fedelmente pointer: lancetta to retrieve: recuperare higher precision: a digital signal can be transmitted more faithfully because errors can easily be corrected, avoiding noise or degradation; ANALOGUE TIME technological improvement: it is easier to add new functions to a digital circuit than to an analogue one; Sample time DIGITAL TIME 126 ELECTRONICS AND ELECTROTECHNOLOGY easier information storage: because of the absence of degradation, stored data can be retrieved undamaged; greater flexibility: digital circuits are more flexible and easier to design as their design process is highly automated.