I want to sense 30 amps of current using op amp in high side. I know that there are many dedicated current sensing amplifiers for this purpose. But I'd like to try it with an op amp. I have tried high side current sensing using the below circuit:
But my output gradually decreases when applying load. Is the above circuit correct? Or where I am going wrong?
EDIT 1 Sorry i forget to say, i want to measure the current in bldc drive. Since there will be problem in measuring current because it contains switching devices.