Differential current transformer and residual current operated protective device

摘要

The present invention discloses a differential current transformer (DCT) and a residual current operated protective device (RCD). In this case, the DCT comprises an iron core and a secondary coil wound on said iron core, and said DCT is connected with a sampling circuit, which sampling circuit is a dual-regulated sampling circuit by both load resistance (Z 1 ) and amplifier feedback loop resistance (Z 2 ). In the technical solution disclosed in the present invention, it is made possible for the size of the DCT to be smaller than that of the DCT in the prior art by providing a dual-regulation circuit, thereby reducing the volume of RCD, and ensuring the linearity and sensitivity performance of the DCT.