Analogue signals use the attributes of the medium for conveying the information of the signal. The information of the electrical system is represented by the change in their voltage, frequency, current or the total charge. A transducer is used for this purpose which helps in converting one type on energy into another.

 

 

Examples:

· A microphone - from a given range, a signal can take any value and different information is represented by each unique signal. A different level of phenomenon is represented by each unique signal. This makes any change in signal meaningful.

· A thermometer - if a signal is representing temperature, one volt would be representing one degree Celsius.

Modulation is one other way to convey analogue signals. In modulation, property alteration occurs in some base carrier signal. There are two types of modulations, the amplitude modulation and the frequency modulation. The frequency modulation causes a frequency change while amplitude modulation leads to altering of the amplitude of a sinusoidal waveform.

Examples:

· Can also be used in pneumatic, hydraulic and mechanical signals. The random thermal vibrations of the atomic particles lead to random disturbances and variations which cause noise in an analog circuit. Low noise amplifiers and shielding are used to reduce these disturbances.