电流，另外线路上的电压一般都比较高如直接测量是非常危险的。电流互感器就起到电流变换和电气隔离作用。 Current, and the voltage on the other line is generally high like direct measurement is very dangerous. Current transformers act as electrical current and electrical isolation. 对于指针式的电流表，电流互感器的二次电流大多数是安培级的（如5A等）。对于数字化仪表，采样的信号一般为毫安级（0-5V、4-20mA等）。微型电流互感器二次电流为毫安级，主要起大互感器与采样之间的桥梁作用。 For a pointer galvanometer, the secondary current of current transformer is mostly ampere-level (e.g. 5A, etc.). For digital instruments, the sampled signals are typically milliampere (0-5v, 4-20ma, etc.). The secondary current of miniature current transformer is milliampere, which mainly ACTS as a bridge between the large transformer and the sampling. 微型电流互感器也有人称之为“仪用电流互感器”。（“仪用电流互感器”有一层含义是在实验室使用的多电流比精密电流互感器，一般用于扩大仪表量程。） Miniature current transformer is also known as "instrument current transformer". (the "instrument current transformer" has a meaning that the multi-current transformer used in the laboratory is more than the precision current transformer, which is normally used to expand the instrument range.) 电流互感器与变压器类似也是根据电磁感应原理工作，变压器变换的是电压而电流互感器变换的是电流罢了。电流互感器接被测电流的绕组（匝数为N1），称为一次绕组（或原边绕组、初级绕组）；接测量仪表的绕组（匝数为N2）称为二次绕组（或副边绕组、次级绕组）。 The current transformer is similar to the transformer and is based on the principle of electromagnetic induction, the transformer is the voltage and the current transformer is the current. A current transformer (N1), called a winding (or primary winding, primary winding); The winding of the measuring instrument (N2) is called a secondary winding (or subside winding, secondary winding). 电流互感器一次绕组电流I1与二次绕组I2的电流比，叫实际电流比K。电流互感器在额定电流下工作时的电流比叫电流互感器额定电流比，用Kn表示。 The current ratio of the current transformer to the current I1 and the secondary winding I2 is called the actual current ratio K. The current ratio of the current transformer is the current ratio of the current inductor to the current transformer, which is expressed in Kn. Kn=I1n/I2n Kn = I1n/I2n 电流互感器（Current transformer 简称CT）的作用是可以把数值较大的一次电流通过一定的变比转换为数值较小的二次电流，用来进行保护、测量等用途。如变比为400/5的电流互感器，可以把实际为400A的电流转变为5A的电流。 The effect of Current transformer, Current transformer CT for short) is the numerical larger Current through a variable than convert numerical smaller secondary Current, used for protection, measurement and other purposes. If the current transformer is 400/5, it can convert the current of a 400A to a current of 5A.