Analogue Signals and Digital Data
The sound waves that your mouth produces when you speak are analogue - the waves vary in a smooth way. These waves can be converted into an electrical signal by a microphone. This electrical signal is also analogue:
- Computer software is a collection of numeric codes which tell the computer what to do
- Text that you type into a computer is stored as numeric codes
- Images inside a computer are stored as numeric values (different values for different coloured pixels)
Computers are unable to process analogues signals because they are digital devices. For digital devices such as computers, to work with analogue devices, conversion is required...
Analogue to Digital Convertor (ADC)
A good example of a computer peripheral that requires an ADC is a microphone. When you plug a microphone into a computer, you are actually plugging it into an ADC which converts the analogue signals from the microphone into digital data that the computer can then process.
Digital to Analogue Convertor (DAC)
A good example of a computer peripheral that requires a DAC is a loudspeaker or headphones. When you plug a loudspeaker into a computer, you are actually plugging it into a DAC, which takes digital data from the computer and converts it into analogue signals which the loudspeaker then converts into sound.