[Paparazzi-devel] IR Sensor Board

[James Galea]

Hello Everyone,

I have recently discovered the paparazzi project and was interested in designing an IR sensor board for stability augmentation. I was having a look at the schematics that are currently on the wiki and was a little confused at the configuration. Please correct me if I am wrong but it seems that the current setup is utilizing a non-inverting op amp configuration with a Vcc/2 offset applied to both the V+ and V- inputs of the op amp. What I don’t understand is how the output will swing between Vcc and GND about the Vcc/2 point, the reason for asking is that we are dealing with DC signals from our sensors with the offset also being DC, this DC offset will also be amplified therefore saturating op amp by swinging to Vcc if (sensor voltage > Vcc/2) or GND if (sensor voltage < Vcc/2). I did a simulation in PSPICE and achieved the same result. Can someone please explain the configuration as I must be missing something.

 

Any help would be greatly appreciated.

 

Kind Regards

James  

 

 

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