Working of current transformer?

The current transformer is used to measure the line current special transformer.
Direct measurement of the current large and small need to range from a few security until tens of thousands of security many ammeter. This gives the instrument manufacture a great deal of difficulty. In addition, some lines are high voltage, direct electricity meter to measure the current of the power lines on the road is extremely dangerous. The current transformer is used to solve these two problems of equipment.
The current transformer has two windings insulated from each other, set in a closed core column. At runtime, the primary winding and the measured line in series, the primary and secondary windings connected measuring instruments (eg, ammeter, power meter and power meter current coil, the low impedance of the relay coil, etc.). Therefore. Measuring the current of the power lines on the road, despite the transformer primary voltage is high, then face transformer secondary voltage is very low, the operator and instrumentation are safe.