Open loop current sensors provide output voltage proportional to measured current without using feedback control. Electrolysis and electrochemistry. The linear range of the open loop current sensor ends when the magnetic core begins to saturate and the output voltage of the current sensor begins to de- grade.
This is illustrated in the graph on the top. There is no change in the cur- rent sensor output voltage once the core or magnetic circuit is saturate as il- lustrated .
The magnetic flux created by the primary current IP is concentrated in a magnetic circuit and measured in the air gap using a Hall device. Current sensors are either open- or closed-loop. The output from the Hall device is then signal conditioned to provide an exact . The Hall sensor is used as a null-detecting device, and the output signal is proportional to the current being driven into the coil, which is proportional to the current being measured. This method is more complex than the open - loop metho but it eliminates any nonlinearities associated with the Hall sensor. Open - loop , through-hole design.
Linear ratiometric output.