Patent ID: 7573274

Claim:
A current sensor for measuring an electric current flowing through a current line, the current sensor comprising: an electrically conductive busbar interposable in the current line to allow the electric current to flow through the busbar, the busbar having a first end portion connectable to a first side of the current line, a second end portion connectable to a second side of the current line, and a middle portion that joins the first and second end portions; an electrically nonconductive case including a case body and a case lid, the case body encapsulating the middle portion of the busbar and having an inner room, the case lid being attached to the case body to cover the inner room; a connector including a connector body and a connector terminal supported in the connector body, the connector body being joined to the case body, the connector terminal having a first portion exposed to the inner room of the case body and a second portion exposed to an outside of the connector body to be connectable to an external device; a semiconductor bare chip arranged in the inner room of the case body and having a detection circuit that detects the electric current based on a resistance of the busbar and a voltage drop across the busbar, the detection circuit outputting a data signal indicative of the detected electric current to the external device via the connector; a first bonding wire that electrically couples the bare chip to the busbar; and a second bonding wire that electrically couples the bare chip to the first portion of the connector terminal of the connector.