Practical DC Differential Amplifier For Sensor Amplifiers Circuit with Op-Am
Dear all hand
When we want to supresse interference in our practical sensor amplifier its mean we must use a pratical differential amplifier for sensor amplifier that has ability to suppress interference, and the answer is differential amplifer.
In many system the input leads pickup 60hz from the power line feeds that permeate all electrical building. In single ended practical sensor amplifier , the 60 hz interfering signal treated as valid input.
But in practical differential amplifier the two leads affected equally by the field so they present equal strength signal to the (-) and (+) input. In differential amplifier , just only the difference of two inputs treated as desired signal.
There are two basic configuration of differential amplifier for sensor:
- The DC differential amplifier circuit for sensor signal amplifier
- Instrumentation amplifier
Below is a figure depicted practical differential amplifier circuit for practical sensor amplifier:
This practical differential amplifier for sensor need to ensure that two input reistance is in balance (R1 = R2) and also feedback resistor in balance (R4=R3), if this two condition is satisfied output will follow this equation : Vout = (Vin+-Vin-) x R3/R1.
Limitation of this practical dc differential amplifier include a reatively low maximum ain and a low input impedance (set by R1 and R2). These problem are overcome in more advanced practical differential amplifier called the instrumentation amplifier.
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