Patent ID: 9701327
Date: 2017-07-11
CPC Classifications: B61L

Claim:
1. A current sensor, complying with Positive Train Control requirements, for monitoring the current flowing in a wire of a circuit, the current sensor comprising: a variable inductance contactless current detector to sense the current flowing in the wire, the variable inductance contactless current detector being a magnetic core, provided with a primary winding and a secondary winding, the secondary winding being made by said wire, the magnetic core being designed to switch from a non-saturate state to a saturate state when the current flowing in the wire moves above a predefined threshold; an internal power source connected to the primary winding; a resistor connected between one terminal of the internal power source and the corresponding terminal of the primary winding, the magnetic core acting as a variable inductance and the resistor, connected in series, forming a voltage divider circuit supplied by the internal power source; a voltage detector to monitor the voltage level across the resistor and generate an output signal, such that when the current flowing in the wire is above the predefined threshold, the magnetic core is in a saturated state and the output signal is ON, and when the current flowing in the wire is below the fixed threshold, the magnetic core is in a non-saturated state and the output signal is OFF; a housing provided with a passage going through said magnetic core and connecting a first face of the housing with a second face of the housing, opposite the first face, said passage receiving said wire in order the current sensor to monitor the current in said wire.