BLDC Motor Current Measurement

[BLDC Info. Seeker]

Does anyone know the most accurate way to measure and record the total current draw of a BLDC motor? Not sure if an Inductive current clamp, shunt resistor, or what method to use and the associated accuracy risks.

Thanks!

 

[dknguyen]

The most accurate method in terms of accuracy, bandwidth, temperature, and stability is a resistor. Where they have their drawbacks is powerhandling and the need to break the circuit to perform the measurement as well as common mode issues associated with high-side placement of the resistor or the ground-plane and potential noise issues with low-side placement of the resistor.