From op amps 101-A, the formula for the gain of an inverting amp is - R (feedback) / R (input), however I'm wondering exactly how R (input) is determined in the first place.
R (input) is always between the input device (such as a transducer) and the summing point. However, if the transducer has its own resistance, it seems like that resistance would be R (input) and another resistor in series would not be required.
My guess is that R (input) might be for impedance matching between the transducer and the amp.
R (input) is always between the input device (such as a transducer) and the summing point. However, if the transducer has its own resistance, it seems like that resistance would be R (input) and another resistor in series would not be required.
My guess is that R (input) might be for impedance matching between the transducer and the amp.