Current sensor
View Patent ↗A rate of change of current sensor includes two measurement coils, arranged such that the turns of the first and second measurement coils are interleaved. The rate of change of current sensor further comprises two return coils, arranged to progress in an opposite direction to the measurement coils. The coils form loops and progress substantially around a target measurement conductor. This ensures that the two measurement coils both receive the same electrostatic coupling from external conductors which are not the target of the measurement operation. Further, the two measurement coils are arranged such that the first coil and the second coil are, on average, the same distance to the current-carrying conductor of interest.
1 . A current sensor comprising:
a substrate comprising a first layer and a second layer;
a first measurement coil;
a second measurement coil;
a first connection element formed on the first layer of the substrate and the second layer of the substrate, the first connection element comprising a first end and a second end and extending alternately between the first layer and the second layer; and
a second connection element formed on the first layer of the substrate and the second layer of the substrate, the second connection element comprising a first end and a second end and extending alternately between the first layer and the second layer,
wherein the first end of the first connection element is coupled to the first measurement coil and the first end of the second connection element is coupled to the second measurement coil,
wherein the second end of the first connection element and the second end of the second connection element are configured to couple to a current measurement circuit,
wherein the first connection element and the second connection element are arranged on the substrate to cross over each other.
2 . The current sensor according to claim 1 , wherein the first connection element and the second connection element are arranged on the substrate in a zig-zag pattern.
3 . The current sensor according to claim 1 , wherein the first connection element and the second connection element are arranged so that each connection element has the same average distance from an external element, with the first connection element and the second connection element having substantially equal noise coupling the external element.
4 . The current sensor according to claim 1 , wherein the first connection element and the second connection element are arranged to form a twisted pair.
5 . The current sensor according to claim 1 , wherein the first connection element comprises a first plurality of connection conductors formed on the first layer and a second plurality of connection conductors formed on the second layer of the substrate, and
wherein the second connection element comprises a third plurality of connection conductors formed on the first layer and a fourth plurality of connection conductors formed on the second layer of the substrate.
6 . The current sensor according to claim 5 , wherein the current sensor further comprises a plurality of vias, and
wherein each connection conductor of the first plurality of connection conductors is coupled to a respective connection conductor of the second plurality of connection conductors using a respective via of the plurality of vias, and
wherein each connection conductor of the third plurality of connection conductors is coupled to a respective connection conductor of the fourth plurality of connection conductors using a respective via of the plurality of vias.
7 . The current sensor according to claim 5 , wherein each connection conductor of the first plurality of connection conductors is arranged to cross over a respective connection conductor of the fourth plurality of connection conductors.
8 . The current sensor according to claim 5 , wherein each connection conductor of the third plurality of connection conductors is arranged to cross over a respective connection conductor of the second plurality of connection conductors.
9 . The current sensor according to claim 1 , further comprising:
a path for at least one current carrying conductor,
wherein the first measurement coil progresses around the path in a first circumferential direction, and wherein the second measurement coil progresses around the path in a second circumferential direction.
10 . The current sensor according to claim 1 , wherein the first measurement coil and the second measurement coil are formed on the first layer and the second layer of the substrate.
11 . The current sensor according to claim 1 , wherein the substrate further comprises a third layer, and wherein the first measurement coil and the second measurement coil are formed on the second layer and the third layer of the substrate.
12 . The current sensor according to claim 11 , wherein a dielectric distance between the first layer and the second layer is less than a second dielectric distance between the second layer and the third layer.
13 . The current sensor according to claim 1 , further comprising:
the current measurement circuit,
wherein the second end of the first connection portion is coupled to a first input of the measurement circuit, and
wherein the second end of the second connection portion is coupled to a second input of the measurement circuit.