Right now I am using a voice coil to provide a force on a thrust stand using a voltage between -5 and 5 volts. On the thrust stand I am measuring displacement with an LVDT and acceleration with an accelerometer. I realized that I could also measure velocity from the voice coil. As the voice coil passes through the magnet a voltage is produced that is linearly proportional to velocity. I created an instrementation amplifier to increase the signal but this only works while I am not applying the large voltage to actuate the voice coil.
I was thinking since I know the input voltage I can pass it through an inverting op amp and then add it to the signal I get from the voice coil. This would remove the input voltage and should just leave me with the signal from velocity correct? I added a diode between the voice coil and input to seperate the signal from the input but I am worried that this will only work when the velocity is in one direction and not in the other.
I was thinking since I know the input voltage I can pass it through an inverting op amp and then add it to the signal I get from the voice coil. This would remove the input voltage and should just leave me with the signal from velocity correct? I added a diode between the voice coil and input to seperate the signal from the input but I am worried that this will only work when the velocity is in one direction and not in the other.
