Technical Information for AC Current Sensor

2016-06-16 09:50:50 MEWOI Electronics Co.,Ltd

Instruction of AC Current Sensor

MEWOI AC Current Sensors(107,108,140,168 and 200 series) are sprit type current sensor with various utility, high reliability and cost-performance for current measurements and controls. 
It is possible to get the current data and interface to the circuit with simple clamping of the conductor by CT(current transformer).
These sensors are applicable for leakage current measurements,load current measurements,power measurements and metering etc.

[Measuring Principle]

[Measuring Principle]

[Equivalent Circuit]

[Equivalent Circuit]









The sprit type AC current sensor is the current transformer with ratio of ”n:1“ for the input current to be measured,when the secondary wound coils are ”n“ turns.
The secondary output current signal(I2) is converted to the voltage signal(E0) by load resistance(RL).
The load resistance value should be selected according to the range to be measured.

EO = K・I 1/n・ RL
(The factor K is depends on the core material and CT structure)

However,when the core material of CT is saturated by the over current flowing to the conductor, the linearity of secondary output current will be distorted and or the error of phase angle will be caused. 
Before using of our current sensor, please refer to the specifications and output characteristic graph.
We recommend your right selection of appropiate sensor for your measuring application.