ANALOGUE AND DIGITAL ELECTRONICS

What Is Analogue and Digital Electronics?

ANALOGUE AND DIGITAL ELECTRONICS: The qualities whose values vary continuously or remain constant are known as analogue qualities. For example, the temperature of air varies in continuous fashion during 24 hours of a day. If we plot a graph between time and temperature recorded at different times, we get a graph as shown bellow. This graph shows that temperature varies continuously with time. Therefore, we say that temperature is an analogue quantity. Similarly, time, pressure, distance, etc. are analogue quantities.

ANALOGUE AND DIGITAL ELECTRONICS

The batch of electrons consisting of circuit which process analogue quantities is called analogue electronics. For instance, the public address system is an analogue system in which the microphones convert sound into a continuously varying electric potential. This potential is an analogue signal which is fed into an amplifier. Amplifier is an analogue circuit which amplifies the signal without changing its shape to such an extant that it can operate a loudspeaker. In this way loud sound is produced by the speaker. Radios, television, and telephones are a few common devises that process analogue signals. 

The quantities whose values vary in non-continuous manner is called digital quantities. Digital variation of analogues signal is shown above in fig. Digital quantities are expressed in the forms of digits or numbers. The branches of electronics which deals with digital quantities is called digital electronics.  Digital electronics uses only two digits '0' and '1' and the whole data is provided in binary form due to which processing of data becomes easy.

A continuously varying signals are called an analogue signal. For maximum value of +5 V  and the minimum value is -5 V is an analogue signal. A signal that can have only two directional value is called digital signals. For example a voltages with square wave form is a digital signal. This signal has only two values i.e, +5 V and 0 V. The high voltages is +5 V and the low voltages is 0 V. It can be seen that digital signals provides the data by a maximum and a minimum voltages level. The changes occurring in the digital signal are not continuous. For quality a long period, the uses of digital electronics was limited to computers only but now a days its application is very wide spread.

Modern telephone system, radar system, naval and other system of military importance, devises to control the operation of the industrial machines, medical equipment and many household appliances are using digital technology.

In our daily life, the quantities that we perceive by our scenes are usually analogue quantities which cannot be processed by digital circuit. To overcome this problem, a special circuit has been designed which converts it to binary form the analogue signal into a digital one in the form of digits in binary form. This circuit is known as Analogue to Digital Converter (ADC). This binary output is then processed by a computer which also gives output in digital form. The output of the computer is again converted into an analogue form by a circuit known as Digital to Analogue Converter. (DAC). As the output DAC is an analogue signal, it can be readily sensed by us. Thus, electronic system used at present consist of both analogue and digital type circuits.