How does a current transformer function?

A current transformer operates through the principle of electromagnetic induction, which allows it to reduce alternating current (AC) to lower, measurable levels. It accomplishes this by having a primary winding through which the current flows and a secondary winding that produces a smaller current proportional to the primary current. When an alternating current passes through the primary winding, it creates a magnetic field that induces a voltage in the secondary winding. This induced current in the secondary winding is a scaled-down version of the current in the primary winding, making it easier and safer to measure.

The design of a current transformer is such that it accurately represents the ratio of primary to secondary current, ensuring that the measurement taken from the secondary circuit is reliable and manageable. This functionality is critical in power monitoring and protection equipment, where high current levels need to be monitored without directly exposing measuring devices to the full load.

In the context of the other options, the function of a current transformer does not involve boosting voltage, converting direct current to alternating current, or amplifying current for clearer measurement. Instead, it emphasizes accurate measurement at safer levels by reducing current, aligning with the principles of direct and alternating current in electrical systems.