Miniature current transformers are divided into miniature current transformers (including miniature current transformers) and miniature voltage transformers. It is a device in the power industry and is generally used in various power instruments for measurement and protection.

Compared with ordinary transformers, micro-transformers have a smaller size (the size of fingernails can be achieved) and higher accuracy (common transformers have four accuracy levels of 0.5, 0.5S, 0.2, and 0.2S, and micro-transformers can reach 0.1 Level) and other characteristics.

The transformer is a transformer with parallel resistance on the secondary side, and the output is current. The miniature current transformer in the miniature current transformer is a parallel resistance on the secondary side, and the output is a voltage. Miniature current transformers are divided into multi-turn winding type (inserted on the circuit board) and through-core type.