I am currently doing a mini project for one of the module in school, where i encountered problem with the accuracy of the differential amplifier output. The signal of interest is from a amplified and filtered IR sensor, the sensor outputs a nominal voltage of about 3V and varies in the mV range when object moves toward or away from it. Therefore I have tried to used a differential amplifier to remove the dc offset, however, by feeding the sensing signal into the positive input and 3Vdc into the negative input, I still got a output voltage of about 1V with a unity gain configuration (just to test out the circuit).
The differential amplifier that i used is connected as the following. And the output voltage should be govern by
Vo = R3/R1 (V1-V2) but that is not what I'm getting. I'm hopping to get a varying range of few voltmeter that I could use to control the duty cycle of a buzzer.
also, Is there a way to control the frequency of my buzzer using the output voltage that I will be getting?
Thank you.
The differential amplifier that i used is connected as the following. And the output voltage should be govern by
Vo = R3/R1 (V1-V2) but that is not what I'm getting. I'm hopping to get a varying range of few voltmeter that I could use to control the duty cycle of a buzzer.
also, Is there a way to control the frequency of my buzzer using the output voltage that I will be getting?
Thank you.