The main difference between digital and analogue electronics is the ability to replicate data and its functions. When working in electronics you are dealing with both analogue and digital systems. You can essentially build analogue systems which will do the same thing as digital systems, but the complexity and design is more difficult. 

An example of an analogue electronic system could be a simple circuit that does not have a microprocessor and works by using components such as resistors, transistors, capacitors, diodes, etc.

Analogue electronics can also use mechanical devices which contain components such as springs, cogs, pipes, and valves which cannot give an accurate replication of their functions the same way that digital devices can. 

Analogue signals can have an infinite amount of possibilities; digital signals are finite. When we compare signal charts we see analogue signals have a wave form that is very smooth, while digital signals have a block appearance as they try to replicate the analogue wave form.

For example, records and tapes are forms of analogue recordings that can be damaged or have even slight imperfections that will cause popping and hissing sounds, not intended or recorded with the master recording. Digital sound recordings can be stored and replicated with each copy having the same quality. There is however a trade-off, as analogue sound will be superior and closer to the actual recorded sound. Digital sound has loss of quality but a better consistency and are easier and cheaper to make copies of.

The similarity between analogue and digital mechanisms in mathematical terms is almost identical.

Many devices have a mixture of analogue and digital components within a given circuit. This is most commonly seen within microcontrollers.  These are usually digital, however often have internal circuitry enabling them to interface with analogue circuits. Examples include analogue-to-digital converters, pulse-width modulation and digital-to-analogue converters.  An analogue-to-digital converter allows a microcontroller to connect to an analogue sensor like photocells or temperature sensors, to read in an analogue voltage. The less common digital to analogue converter allows a microcontroller to produce analogue voltages, which is handy when it needs to make sound.


Binary is the basis of all computer electronic logic. It is the simple the representation of usually a “0” and a “1” which translates to much the same as a switch OFF and ON. The numbers are put together to form a series of 1s and 0s, which will form an operation or representation of something such as a number or letter. Each 1 or 0 is known as a “bit” of information. These form a collection and when there are 8 bits, it is known as a byte. There are 1024 bytes to 1 Kilobyte (KB), 1048576 bytes to a megabyte (MB).

If you were to look at a number or text, this can be represented by a binary sequence of 1s and 0s.
E.g. the number one (1) is simply a binary “1”, and Zero (0) is a binary “0”
The number (2) is made up of a “1” and a “0” i.e. 10.
3 is 11
` 4 is 100
5 is 101
6 is 110
7 is 111
8 is 1000
9 is 1001
10 is 1010

The digits are counted much the same as you would count from 1-10 (there are 9 numbers before the counter must reset and then put a 1 and a 0 making the number 10). 

Because in binary there are only 2 numbers to work with, these are reset more often, but the concept is the same. 0 is 0 and 1 is 1 but then to get 2 you put a 1 and 0 together (10) to get 3 you simply add 1 to 10 to make 11.
To get 4 you have reached the limit of numbers you can use and they are all 1s so you go up to a 3-digit binary combination starting with a 1 and then two 0s.

To get 5 you are just adding a 1 to the last value, etc.
You can search the internet for a text to binary converter to see how each letter is represented in binary code.

There may be 6 letters in the word “binary” and 6 groups of 8 ones and zeroes. Each combination represents each letter and forms a “byte” of information.

Binary can also be used for arithmetic, i.e., addition, subtraction, multiplication, division, using the ones and zeroes to form an algorithm which uses logic to determine the result.
In a computer and electronic systems there are layers that sit on top of the binary as humans would have a hard time deciphering all the 1s and 0s and what they mean or do. Binary is known as the first- generation programming language. 
The first computers would use punch cards which would have holes in them to represent the 1s and 0s, these formed 6 and 8-bit bytes (1 byte = 8 bits)

There are many advantages to using binary, with the main ones being as follows:

  • Binary devices are simple and easy to build.
  • Binary signals are unambiguous.
  • Flawless copies can be made of binary data.
  • Anything that can be represented with a pattern can be represented with a pattern of bits (i.e. binary)

Mechanical analogue computers and noise

The benefit of digital computers and devices over analogue ones comes down to the “noise” and the variation of it during operation of analogue devices. Digital devices do not suffer the same effects of noise; there is no noise to affect reliability or accuracy of data transmission. Analogue systems can have variations in transmission making them less consistent. Analogue signals are continuous signals that can be constant or vary where as digital signals are discrete meaning they can either be on or off, the transmission cannot change or get it wrong unless it is tampered with.

Digital/Analogue audio

Digital audio processing is the modern way that music is produced and stored. It can be seen in all forms from the music that we listen to, the ringtone on your phone, all comes from audio waves that have been digitally processed and stored onto a chip or in memory (CD, DVD, HDD etc) and output via a speaker when it is programmed to do so.

It does this by first collecting the information digitally or producing it digitally, when collecting the information, it needs computers and electronic components which will use microphones to record the sound and translate it to digital bits of information. The collective bits of information form the waves of the sound that can be interpreted and reproduced exactly the same for every copy. Essentially digital audio is just a collection of binary, 1s and 0s. 

Digital/Analogue images

The digital image process is similar to the audio process in the way that the conversion of information happens from real world analogue to computer digital. Analogue images have the same wave structure as audio analogue signals. The negative in analogue images, such as old cameras or films, can contain scratches and blemishes which will be unique in every copy and when reproduced from a reproduction will inherit the defects, where as digital images will not alter in their quality when copied, digital images and sound can be manipulated with software. You can make the volume of audio louder than originally recorded or delete or modify part of an image or even enhance an image relatively easily.

Analogue radio/tv and digital transmission of signals

Not too many years ago, many television/radio broadcasts used analogue technology.  This is prone to fading and loss of quality.  Many broadcasts now use digital TV (DTV).  Digital TV reproduces crystal clear picture and sound without fading or interference and enables TV stations to broadcast multiple channels with different programming.

Analog television transmits programming in a continuous signal. This signal varies in amplitude, depending on the information contained in the picture.  The television signal goes up and down depending on what’s being broadcast.  This analogue signal is transmitted on a particular radio frequency, from the television station’s transmitting antenna over the air to the receiving antenna connected to your TV set. Each television station is assigned a particular frequency that corresponds to its channel number. When you tune your TV to a given channel, you’re actually choosing to receive transmissions on that particular frequency.  Unfortunately, this analogue signal is far from perfect. It might not always exactly reproduce the original programming. It can easily deteriorate over long distances. And it can also suffer interference from other sources, producing ghost images and static.

A digital broadcast converts the programming into a stream of binary on/off bits.  Each bit represents a small part of the picture, and all the bits combine to reproduce the original picture.  The primary advantage of digital broadcasting is that these binary bits recombine to reproduce an exact copy of the original material. The picture and sound received from a digital transmission are always identical to the original source.  Digital signals don’t weaken over distance as analogue signals do. As long as the signal can be received, the picture is perfect, with no degradation or ghosting.
Digital is a more efficient technology. A digital transmission requires less bandwidth than a similar analogue broadcast; this lets local television stations broadcast two, three, or even four digital channels in the space of a single analogue channel.


You may also be interested in....


Electronics underpins work in so many industries, from I.T. and alternative energy to mechanics and robotics.

View Course


Learn how motors, engines and machines work.

View Course