If the site's Ad gain is 1000 (times). Determine the resistive components of the circuit.
I came to the conclusion that vo / (V1-V2) = (R3 / R2) (1+ {2R1 / Rgain}) Take the traditional 3-opamp instrumentation amplifier, keep in mind that operational amplifier 1 is inverted
FYI , it is Instrumentation, not Instrumental (pertains to music)
G= R3/R2 (1+2R1/Rgain)
R3=100K
R2=10K
R1=9k9
Rgain=100
keep in mind that operational amplifier 1 is inverted
Indeed, this is some nonsense circuit with positive feedback. A1 output will randomly saturate into either of its supply voltages. I suppose that has to be a mistake.
FYI , it is Instrumentation, not Instrumental (pertains to music)
I had a class in uni called "Instrumental Chemistry". We played 0 music.
https://www.elprocus.com/what-is-an-instrumentation-amplifier-circuit-diagram-advantages-and-applications/
If you read the paragraph . Instrumentation Amplifier using Op Amp
"The instrumentation amplifier using op-amp circuit is shown below.
The op-amps 1 & 2 are non-inverting amplifiers and op-amp 3 is a difference amplifier. These three op-amps together, form an instrumentation amplifier. Instrumentation amplifier’s final output Vout is the amplified difference of the input signals applied to the input terminals of op-amp 3.Let the outputs of op-amp 1 and op-amp 2 be Vo1 and Vo2 respectively."
This leads me to believe that the circuit is drawn wrong on that web sight. Op amps 1 and 2 must be non-inverting.