Hello,
My team is trying to increase the current capacity of the shunts. We have the 3 (U, V, and W) shunt gains figured out but we're stuck on figuring out how to modify the Ifb-sum gains. It uses a non-inverting amplifier where Av = 1 + R_2 / R_1, where R_2 was calculated as 2475.69ohms and R_1 is 100ohms. We got a gain of 25.756 off the amplifier but it's being referenced to 3.0V giving us 0.3V headway. If 10 amps where to come in across the 0.02 ohm current shunt(s), 2.0V would be multiplied by the huge gain which would then feed into the mc's ADC input. Are we misunderstanding something here?
On the U, V, and W current shunts to handle 15.0A, we are planning to change the gain on their amplifiers from 8.25 to 5.526. We feel that this is correct. It's just we're not sure about how the Ifb-sum works.
Thanks,
Scott
