FAQ | Feb 21,2023
Current sensor is a kind of detection device, can feel the measured current information, and can detect the perceived information, according to a certain law into a certain standard of electrical signal or other required form of information output, in order to meet the information transmission, processing, storage, display, record and control requirements. Is a kind of sensor classification, its main signal source is the size of the current acquisition signal! The main parameter is its current size! The detection method is generally used to detect current characteristics of devices, generally ammeter and so on.
The working principle of current transmitter is mainly Hall effect principle. Take the principle of zero-flux closed-loop product as an example:
1. When the original side wire passes through the current sensor, the original side current IP will generate magnetic force lines. The original side magnetic force lines are concentrated around the air gap of the magnetic core. This tiny signal can be converted into secondary side current IS by subsequent electronic circuit, and the following relationship exists: IS* NS= IP*NP, where IS – secondary side current; IP – primary side current; NP — number of turns of primary side coil; NS — number of turns of secondary side coil; NP/NS – turns ratio, generally take NP=1. The output signal of the current sensor IS the side current IS, it is proportional to the input signal (original side current IP), IS generally small, only 10~400mA. If the output current passes through the measured resistance RM, a voltage output signal of several volts proportional to the original side current is obtained.
2, sensor power supply voltage VA VA refers to the power supply voltage of the current sensor, it must be in the range specified by the sensor. Beyond this range, the sensor cannot work normally or its reliability decreases. In addition, the supply voltage VA of the sensor is divided into positive ji supply voltage VA+ and negative ji supply voltage VA-. Note that the power supply voltage VAmin of the single-phase power supply sensor is twice that of the two-phase power supply voltage VAmin. Therefore, the measurement range of the two-phase power supply sensor should be higher than that of the two-phase power supply sensor.
3, measurement range Ipmax Measurement range refers to the maximum current value that can be measured by the current sensor, the measurement range is generally higher than the standard rating IPN.
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