Magnetic read device

1. A magnetic read device, comprising:

a magnetic read head ( 71 ; 81 ) comprising a first magnetic circuit ( 40 ) providing, at the terminals of a first conductive winding ( 45 ), a signal (VOUT) representative of magnetic flux variations at a first distance (d 1 ) of a front face of the head; and

a second magnetic circuit ( 70 ) providing, at the terminals of a second conductive winding ( 75 ) connected in phase opposition to the first winding, a signal (VB) representative of magnetic flux variations at a second distance (d 2 ), greater than the first distance, from the front face of the head,

wherein the first conductive winding ( 45 ) is formed around a magnetic core ( 41 ) and the second conductive winding is not formed around a magnetic core.

2. The device of claim 1 , wherein the first and second windings are series-connected.

3. The device ( 31 ″) of claim 1 , wherein the first and second windings are connected in parallel.

4. The device ( 31 ; 71 ; 81 ) of claim 1 , wherein the second winding is comprised in the read head.

5. The device of claim 1 , wherein:

the first winding belongs to a first magnetic circuit ( 40 ) providing, across the first winding, a signal (VOUT) representative of the magnetic flow variations at a first distance (dl) from a front surface of the head; and

the second winding belongs to a second magnetic circuit ( 50 ; 70 ) providing, across the second winding, a signal (VB) representative of the magnetic flow variations at a second distance (d 2 ), greater than the first distance, from the front surface of the head.

6. The device of claim 1 , wherein the second distance is greater by from 0.3 to 3 mm than the first distance.

7. The device ( 31 ; 71 ) of claim 5 , wherein the first magnetic circuit ( 40 ) comprises a first magnetic ring ( 41 ) opened by a first gap ( 43 ), the first gap being located at the first distance (dl) from the front surface of the head.