harinii
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Hi everyone!
I am building a pulse oximeter for my final year project. Our first step was to get waveforms at the output of the photodiode when red and IR light pass through the finger. We have a simple current to voltage converter(initially just a resistor then we tried using an I to V converter built using uA741) at the output of the photodiode. But we could not obtain AC waveforms.
So we tried using a phototransistor as sensor because we thought the problem was insensitivity of photodiode. But we could not get an AC waveform at the output of phototransistor too.
Please help me out!
I am building a pulse oximeter for my final year project. Our first step was to get waveforms at the output of the photodiode when red and IR light pass through the finger. We have a simple current to voltage converter(initially just a resistor then we tried using an I to V converter built using uA741) at the output of the photodiode. But we could not obtain AC waveforms.
So we tried using a phototransistor as sensor because we thought the problem was insensitivity of photodiode. But we could not get an AC waveform at the output of phototransistor too.
Please help me out!