I am measuring the phase voltage of a BLDC motor as shown in the figure below. As the motor doesn't have neutral point, a virtual neutral point(VN) is created by the resistor network and three-phase voltage are measured with oscilloscope Probe A, Probe B and Probe C. First let me know if my measurement setup is correct!!!
I want to understand why there is a spike in the back EMF as shown in the figure below. As described in theory the Back EMF of floating phase ant any instant should ramp up or down but why there is a huge spike? How to reduce the spike?