The rated primary current has a wide range, which is used for the power-taking device of the anti-theft electric energy meter, etc., and can supply power to its internal three-terminal regulator; For example, when the neutral line is disconnected, the secondary winding of the EHC-VCT series current transformer generates power to make the electric energy meter work normally, which can meet the power supply needs of the three-terminal regulator and can be used to prevent electricity theft.