In general terms, an Analog is an adjective that describes the continuous process of something or transmission with two different variables. Analog represents an object that provides the original or actual value, such as an analog hand-clock is an analog device because the clock indicates the time of day at each instant of time. We live in an analog world, as the sound we hear, the smells that we can smell, etc., all these are infinite and continuous in nature and hence said as analog values.
Analog and Digital terms are commonly used together but in contrast with each other. The digital term has come with computers as a computer only understand the digital values, and every computer device is digital, whereas human experiences are said as analog.
Use of Analog in different fields
The term analog is broadly used in the field of computing and electronics. Both digital and analog are basic and important terms to understand the concept of computing and electronics.
- Analog Signal
An Analog signal is a continuous signal in which information is encoded as the continuous variable. In an analog signal, one time-varying variable such as voltage, pressure, etc., represents another time-varying variable.
It is time-varying and also restricted between the +12V to -12V voltage range. However, there are infinite numbers of values that lie between the given continuous voltage range.
Analog signals often use the property of a related medium to transmit the data from one place to others, such as in electrical wires. Signals move through the wire and transmit electric signals from a power station to transformers or houses. Analog signals can be represented by plotting a graph between various physical quantities such as sound, temperature, pressure, and positions, etc.
Example: Below is a graph plotted between two physical parameters, i.e., Voltage vs. Time (V-T). This graph shows a continuous curve without having any breaking point or discontinuity:
- Analog Devices
Analog devices are those devices that work on analog signals. Analog devices are a combination of both analog machine and media that helps to transmit continuous or analog data from one place to another.
There are some electrical and non-electrical examples of Analog devices, which are as follows:
- Electrical Analog Devices:
- Telautograph: It is an analog ancestor to the modern fax machine and was the first device to transmit pictorial information to a stationary sheet of papers.
- Analog Synthesizer: These are the devices that help to generate sound electronically through analog circuits and analog computers.
- Analog Television: These devices help to encode televisions and convert the picture and sound data in the form of an analog signal. However, it can be seen by plotting a graph between the amplitude and frequency of a broadcasting signal. NTSC, PAL and UNIT are various examples of analog television system.
- Non-Electrical Devices:
There are plenty of devices that help to convey analog signals without having any electrical medium, such as clocks, governor of steam engines, planimeter (to calculate the area of closed shape), Kelvin's tide predictor, acoustic rangefinders, servomechanisms and speedometers, etc.
- Analog Computers
Analog computers are those computers that work on the principle of Analog signals and use various electrical, mechanical and hydraulic techniques to solve the various problems.
In other words, an Analog computer as one type of physical system which determines the behaviour of another physical system. Further, modelling the original physical system in a computer device is called simulation.
Characteristics of Analog Signals
There are various important characteristics of an Analog Signal, which are as follows:
- Analog Signals are time-varying electronic signals.
- Analog Signals are continuous in nature.
- It can be either periodic or non-periodic.
- These are less accurate signals in comparison to Digital signals.
- It helps to determine the behaviours of various physical parameters.
- Analog signals can be denoted by a curve or straight line.
- The values lie between negative to positive.
- Analog Signals are originally generated; hence they record the physical waveforms.
- Analog signals can get affected by noise during data transmission.
- Analog signals require less Bandwidth (BW).
- It consumes more power than a digital signal.
- It is more helpful for audio/video recordings.
Advantage of Analog
Analog signals are always very helpful in various fields. There are some important advantages of Analog Signals, which are as follows:
- Analog signals are best suited for audio/video recording.
- Analog systems are cheap in cost.
- Analog signals require less bandwidth.
- These signals can easily process and are portable.
- It doesn't require any graphic board.
- It provides a more accurate representation of sound than a digital signal.
- Analog Signals are originally generated or natural signals; hence they record the physical waveforms.
- It has more density than the digital signal, so it can produce more refined data.
Disadvantages of Analog Signals
There are some disadvantages that can be seen by using Analog signals, which are as follows:
- Analog signals produce lower quality signals in comparison to Digital signals.
- Analog devices are much costlier than Digital and also can't be carried out easily.
- It limits the editing feature while transmitting data.
- Synchronization is very difficult in analog signals.
- It provides a poor multi-user interface (UI).
- Data in analog signals can be easily corrupted.
What is Digital Signal?
Digital or sometimes called Discrete signals are the types of signals that are used to represent data in a sequence of separate values at any point in time. Unlike analog signals, these are not continuous in nature but are discrete in value and time. These signals can be represented via binary numbers and also lies between different values of the voltage range. In short, digital signals are time-dependent signals that can be denoted by sine waves between two physical parameters.
Key differences between Analog and Digital Signals:
Analog and Digital both are used to convey data or signals from one place to another. Analog signals can be represented by electronic pulses or sine waves, while digital signals can be represented by binary digits (0 or 1) or square waves.
There are some key differences between Analog and Digital signals, which are as follows:
|Analog signals are continuous and real signals.
||Digital signals are discrete and time-dependent.
|It can be represented by sine waves.
||It can be represented by square waves.
|It uses a continuous range of values to represent information.
||It uses binary digits 0 and 1 to represent information.
|These signals contain lower bandwidth.
||It contains a relatively higher bandwidth.
|Data in Analog transmission may be corrupted by noise.
||It is comparatively less noise effective hence doesn't corrupt the entire data during transmission.
|It is not flexible in hardware implementation.
||It is relatively flexible to implement in hardware.
|It is best suited for audio/video transmission.
||It is best suited for computers and digital electronics.
|It offers real-time processing with lower bandwidth.
||It may or may not offer real-time processing and also requires higher bandwidth.
|It doesn't contain a fixed range of values.
||It contains finite numbers, i.e., 0 and 1.
|It gives some observational errors due to having a scale cramped at the lower end.
||It doesn't give any observational error as digital; instruments don't include any scale.
|Analog systems are cost-effective.
||Digital systems are costlier then analog.
|Power consumptions in Analog systems are high.
||It consumes less power than analog.
|Data is stored in waveform signals in analog systems.
||Data is stored in the form of bits, i.e., 0 or 1.
|Examples of Analog devices: Temperature sensors, FM radio signals, photocells, light sensors, resistive touch screen, voice radio using AM frequency, etc.
||Examples of Digital devices: Computer, CD and DVD, etc.