Concept Flashcards#
What is a transducer?
A device that interfaces the physical world with the electrical world.
What is an input transducer?
A device that converts a physical signal into an electrical signal.
What is an output transducer?
A device that converts an electrical signal into a physical signal.
Give an example of an input transducer.
A microphone, which converts sound waves into an electrical signal.
Give an example of an output transducer.
Speakers or headphones, which convert electrical signals into sound waves.
What is instrumentation?
Instrumentation connects input and output transducers in a meaningful way.
Why is signal conditioning often required?
Most input transducers produce signals that are too small or improperly scaled to directly drive output transducers.
What two operations are commonly used in instrumentation systems?
Amplification (gain) and biasing (offset).
What does an amplifier do?
It multiplies an input signal by a constant gain factor \(K\) to increase its magnitude.
Define the gain of an amplifier.
Gain \(K\) is the scalar multiplier that relates input and output:
When is amplification alone sufficient for signal conditioning?
When both input and output dynamic ranges are symmetric about zero.
What is biasing in an instrumentation system?
Adding a DC voltage \(B\) to shift the output signal to the required range.
What device is used to add two voltages together?
A summer.
Write the general equation for an instrumentation system.
Where:
\(K\) = gain
\(B\) = DC bias
Why can a single amplifier sometimes not solve an instrumentation problem?
Because a single gain value may scale the signal correctly at one operating point but not at another, requiring both gain (\(K\)) and bias (\(B\)) to match two extreme conditions.