Purposes of current sense resistors
Followings are three applications of current sensing in electrical circuits.
A circuit operation needs to be stopped for safety when an overcurrent flows due to a circuit malfunction or overload. If the current exceeds the set value, the resistor judges it as abnormal and interrupt the output.
A resistor detects the peak of sawtooth current flowing through the reactor of DC-DC converters and uses it for control.
Also, since the phase and time of the current should be controlled precisely to rotate a three-phase motor, the resistor detects the current flowing in each phase and gives the feedback to the control circuit. Used mainly for electric power steering (EPS) and air conditioners.
Current management (Battery management)
Devices that operate on secondary batteries sensing current and voltage applied to the battery and optimize circuit operation to enable the ascertaining of battery life and the long-time operation of devices.