Patent ID: 7969271

Claim:
A current transformer comprising: a bobbin comprising a bobbin body and a concave structure, wherein a channel runs through said bobbin body, and said concave structure is disposed in said bobbin body; a primary winding coil wound around said bobbin body; a conductive pillar partially accommodated within said concave structure; a magnetic core assembly comprising a first magnetic core and a second magnetic core, wherein said first magnetic core and said second magnetic core are partially embedded into said channel, and said concave structure is partially enclosed by said second magnetic core; and a covering member cooperating with said concave structure to shield said conductive pillar, wherein said conductive pillar and said second magnetic core are separated from each other by said covering member, so that a creepage distance between said conductive pillar and said primary winding coil and a creepage distance between said conductive pillar and said magnetic core assembly are increased.