Advantages of open-loop principle Hall current sensors

Very often, there is a misunderstanding that the closed-loop principle sensors have high linearity, high accuracy, high bandwidth, fast response time, and it seems to one-sidedly think that the closed-loop ones are better than the open-loop current sensors.

   Open-loop Hall current sensors are indeed compared to the closed-loop principle of Hall current sensors, in linearity, accuracy, bandwidth, response time and other parameters on the performance is very good, is better than the open-loop principle of Hall current sensors. However, when used in practice, the above advantages are not very high requirements, open loop also has a closed loop does not have the advantage.

   1, first of all, the open-loop Hall current sensor, because of the principle of simple, so the structure is very good to deal with, open-ended, closed-ended can be, in the case of installation space requirements, open-loop more flexible, easier to meet the requirements of the installation; closed-loop principle of the current sensor is not unable to open the open-ended, open-ended high cost, the structure of the requirements of the high cost of a large cost, is not absolutely necessary, will not be selected for the structure of this;

  2, the open-loop principle of the Hall current sensor impulse current is greater, especially in the case of particularly high peak value, no effect on the sensor, ten or even twenty times the impulse current will not cause damage to the sensor, but the closed-loop can not be, when more than the measurement range, the phenomenon of magnetisation will occur;

 3, open-loop power consumption, close to constant, basically maintained at about 30MA (voltage output type) or 50MA (current output type), while the closed-loop principle of the sensor, * small power consumption or 50MA, static power consumption plus dynamic power consumption, the power supply power is an obvious requirement, especially in the multi-shared power supply, or even the need for a separate power supply system, and the open-loop principle of the current sensor is generally shared with the MCU power supply (MCU). The open-loop principle of the current sensor is generally shared with the MCU power supply (PLC, data acquisition card, intelligent instrumentation, etc.).

 4, because of the relationship between the principle of operation, open-loop current sensing, small cutout, small size, but the measurement current can be very large, for example:FS2500AX for the open-loop principle of Hall current sensors, opening size of only 64mm * 21mm, but the peak measurement current can be up to 5000A.

Summarise the above belongs to the open-loop principle of current sensors and closed-loop principle of Hall current sensors and no advantage or disadvantage, just use the different requirements of different occasions, the choice is different, each has its own advantages.

Specific selection time to pay special attention to, clear their own requirements for the sensor, and then selected for their own sensors is very important.