Explaining Symmetric Input in Instrumentational & Differential Amplifiers

[Garoll]

I would like to ask you what it is meant by "symmetric input" in the instrumentational amplifier schematics and in the differential amplifier? I can`t understand what is the difference between symmetric and non symmetric input and output as parameters. Can anyone explain ?

Thanks

 

[Bob S]

I would like to ask you what it is meant by "symmetric input" in the instrumentational amplifier schematics and in the differential amplifier? I can`t understand what is the difference between symmetric and non symmetric input and output as parameters. Can anyone explain ?

Probably they mean a balanced diferential input, like

V_plus = A·sin(ωt), and

V_minus = -A·sin(ωt)

Bob S