A kind of based on the measurement magnetic direction of giant magnetoresistance effect and the sensor of intensity
Technical field
The present invention relates to a kind ofly, belong to the magnetic-field measurement technical field based on the measurement magnetic direction of giant magnetoresistance effect and the sensor of intensity.
Technical background
In transmission line of electricity and transformer station, running current, short-circuit current and dash current space around produce very strong magnetic field.It is carried out measuring key parts is exactly magnetic field sensor.This sensor is not only wanted to tolerate the highfield environment, and will have suitable sensitivity, can measure the size and Orientation in magnetic field.
The magnetic field sensor of electromagnetic induction principle is generally adopted in traditional magnetic-field measurement.Novel magnetic field sensor mainly contains the Hall sensor, Fibre Optical Sensor and giant magnetoresistance sensor.No matter be traditional induction magnetic field sensor or novel magnetic field sensor, the magnetic field size on all can only a certain direction of perception can not directly be measured its size and Orientation for the magnetic field that direction is unknown.
Wherein, giant magnetoresistance sensor is the magnetic field sensor that a kind of volume is little, frequency response is wide, highly sensitive, with low cost, and its conventional bridge structure is as shown in Figure 1.But conventional bridge structure is the direction in energy measurement magnetic field not, therefore presses for a kind of new construction that can measure magnetic direction and intensity simultaneously of research.
Summary of the invention
The objective of the invention is to propose a kind of based on the measurement magnetic direction of giant magnetoresistance effect and the sensor of intensity.Change the structure of conventional magnetic field sensor; Utilize giant magnetic resistor material to measure the direction and the intensity in magnetic field for the Changing Pattern of the sensitivity in different directions magnetic field; To be used for the terrestrial magnetic field; In all kinds of magnetic-field measurements such as transmission line of electricity and magnetic field, transformer station place, and be used for the current measurement in electric system and the electronic system.
The present invention propose based on the measurement magnetic direction of giant magnetoresistance effect and the sensor of intensity, comprising:
The X sensing unit; Be used for the magnetic-field component on the measured X direction; The X sensing unit is made up of first electric bridge and second electric bridge; Described first electric bridge is made up of first giant magnetoresistance, the first shielding resistance, second giant magnetoresistance and secondary shielding resistance; Described first giant magnetoresistance, the first shielding resistance, second giant magnetoresistance and the end to end back of secondary shielding resistance form bridge structure, and the link of described first giant magnetoresistance and secondary shielding resistance is the positive input terminal of first electric bridge, and the link of second giant magnetoresistance and the first shielding resistance is the negative input end of first electric bridge; The link of first giant magnetoresistance and the first shielding resistance is the negative output terminal of first electric bridge, and the link of second giant magnetoresistance and secondary shielding resistance is the positive output end of first electric bridge; Described second electric bridge is made up of the 3rd giant magnetoresistance, the 3rd shielding resistance, the 4th giant magnetoresistance and the 4th shielding resistance; Described the 3rd giant magnetoresistance, the 3rd shielding resistance, the 4th giant magnetoresistance and the end to end back of the 4th shielding resistance form bridge structure; The link of described the 3rd giant magnetoresistance and the 4th shielding resistance is the positive input terminal of second electric bridge; The link of the 4th giant magnetoresistance and the 3rd shielding resistance is the negative input end of second electric bridge; The link of the 3rd giant magnetoresistance and the 3rd shielding resistance is the negative output terminal of second electric bridge, and the link of the 4th giant magnetoresistance and the 4th shielding resistance is the positive output end of second electric bridge; The positive output end of described first electric bridge links to each other with the positive input terminal of second electric bridge, and the negative output terminal of first electric bridge links to each other with the negative input end of second electric bridge;
The Y sensing unit; Be used to measure the magnetic-field component on the Y direction; The Y sensing unit is made up of the 3rd electric bridge and the 4th electric bridge; Described the 3rd electric bridge is made up of the 5th giant magnetoresistance, the 5th shielding resistance, the 6th giant magnetoresistance and the 6th shielding resistance; Described the 5th giant magnetoresistance, the 5th shielding resistance, the 6th giant magnetoresistance and the end to end back of the 6th shielding resistance form bridge structure, and the link of described the 5th giant magnetoresistance and the 6th shielding resistance is the positive input terminal of the 3rd electric bridge, and the link of the 6th giant magnetoresistance and the 5th shielding resistance is the negative input end of the 3rd electric bridge; The link of the 5th giant magnetoresistance and the 5th shielding resistance is the negative output terminal of the 3rd electric bridge, and the link of the 6th giant magnetoresistance and the 6th shielding resistance is the positive output end of the 3rd electric bridge; Described the 4th electric bridge is made up of the 7th giant magnetoresistance, the 7th shielding resistance, the 8th giant magnetoresistance and the 8th shielding resistance; Described the 4th electric bridge forms bridge structure by the 7th giant magnetoresistance, the 7th shielding resistance, the 8th giant magnetoresistance and the end to end back of the 8th shielding resistance; The link of described the 7th giant magnetoresistance and the 8th shielding resistance is the positive input terminal of the 4th electric bridge; The link of the 8th giant magnetoresistance and the 7th shielding resistance is the negative input end of fourth stage electric bridge; The link of the 7th giant magnetoresistance and the 7th shielding resistance is the negative output terminal of the 4th electric bridge, and the link of the 8th giant magnetoresistance and the 8th shielding resistance is the positive output end of the 4th electric bridge; The positive output end of described the 3rd electric bridge links to each other with the positive input terminal of the 4th electric bridge, and the negative output terminal of the 3rd electric bridge links to each other with the negative input end of the 4th electric bridge;
The positive input terminal of the positive input terminal of first electric bridge of X sensing unit and the 3rd electric bridge of Y sensing unit is the positive pole of same power supply, and the negative input end of the negative input end of first electric bridge of X sensing unit and the 3rd electric bridge of Y sensing unit is the negative pole of same power supply.
The present invention propose based on the measurement magnetic direction of giant magnetoresistance effect and the sensor of intensity; Be applicable to the intensity in the unknown magnetic field of direction and the measurement of direction; Can either be applied to the terrestrial magnetic field; In all kinds of magnetic-field measurements such as transmission line of electricity and magnetic field, transformer station place, also can be used for the current measurement in electric system and the electronic system.This size sensor is less, is applicable to the in-vitro measurements and the distributed measurement in magnetic field.The orthogonal measuring structure that this magnetic field sensor uses can be measured the intensity and the direction in magnetic field simultaneously, and in the direction of sensor when bigger variation takes place, still can guarantee stable output voltage, improved measuring stability greatly.This sensor uses giant magnetic resistor material, and its response speed is fast, highly sensitive, has greatly improved the survey frequency scope and the response speed of sensor.
Description of drawings
Fig. 1 is the bridge structure synoptic diagram of the giant magnetoresistance magnetic field sensor of routine.
Fig. 2 is the electrical block diagram based on the sensor of the measurement magnetic direction of giant magnetoresistance effect and intensity that the present invention proposes.
Fig. 3 is the measuring principle synoptic diagram of the magnetic field sensor that proposes of the present invention.
Among Fig. 1-Fig. 3,1,3 are respectively the first, the second giant magnetoresistance in the conventional bridge structure; 2,4 be respectively first in the conventional bridge structure; Secondary shielding resistance, 5 and 6 are respectively the positive input terminal and the negative input end of electric bridge, and 7 and 8 are respectively the positive output end and the negative output terminal of electric bridge.9 is the X sensing unit, and 10 is the Y sensing unit; Wherein, R
X1, R
X2, R
X3, R
X4Be respectively the first, the second, third and fourth giant magnetoresistance in the X sensing unit, R
SX1, R
SX2, R
SX3, R
SX4Be respectively the first, the second, the third and fourth shielding resistance in the X sensing unit; R
Y1, R
Y2, R
Y3, R
Y4Be respectively the the five, the six, the 7th and the 8th giant magnetoresistance in the Y sensing unit, R
SY1, R
SY2, R
SY3, R
SY4Be respectively the the five, the six, the 7th and the 8th shielding resistance in the Y sensing unit; Vcc is a positive source, and GND is a power cathode; U
1+And U
1-Be respectively the positive output end and the negative output terminal of first electric bridge of X sensor unit, U
1 2 +And U
1 2 -Be respectively the positive output end and the negative output terminal of second electric bridge of X sensor unit; U
2+And U
2-Be respectively the positive output end and the negative output terminal of the 3rd electric bridge of Y sensor unit, U
2 2 +And U
2 2 -Be respectively the positive output end and the negative output terminal of the 4th electric bridge of Y sensor unit.U
1Be the field signal on the X sensitive axes, U
2Be the field signal on the Y sensitive axes, U is the resultant magnetic field signal in the plane.
Embodiment
The present invention propose based on the measurement magnetic direction of giant magnetoresistance effect and the sensor of intensity, its structure is as shown in Figure 2, comprising:
X sensing unit 9 is used for the magnetic-field component on the measured X direction, and the X sensing unit is made up of first electric bridge and second electric bridge, and described first electric bridge is by the first giant magnetoresistance R
X1, first the shielding resistance R
SX1, the second giant magnetoresistance R
X2With the secondary shielding resistance R
SX2Form the described first giant magnetoresistance R
X1, first the shielding resistance R
SX1, the second giant magnetoresistance R
X2With the secondary shielding resistance R
SX2End to end back forms bridge structure, the described first giant magnetoresistance R
X1With the secondary shielding resistance R
SX2Link be the positive input terminal Vcc of first electric bridge, the second giant magnetoresistance R
X2With the first shielding resistance R
SX1Link be the negative input end GND of first electric bridge, the first giant magnetoresistance R
X1With the first shielding resistance R
SX1Link be the negative output terminal U of first electric bridge
1-, the second giant magnetoresistance R
X2With the secondary shielding resistance R
SX2Link be the positive output end U of first electric bridge
1+Described second electric bridge is by the 3rd giant magnetoresistance R
X3, the 3rd the shielding resistance R
SX3, the 4th giant magnetoresistance R
X4With the 4th shielding resistance R
SX4Form described the 3rd giant magnetoresistance R
X3, the 3rd the shielding resistance R
SX3, the 4th giant magnetoresistance R
X4With the 4th shielding resistance R
SX4End to end back forms bridge structure, described the 3rd giant magnetoresistance R
X3With the 4th shielding resistance R
SX4Link be the positive input terminal of second electric bridge, the 4th giant magnetoresistance R
X4With the 3rd shielding resistance R
SX3Link be the negative input end of second electric bridge, the 3rd giant magnetoresistance R
X3With the 3rd shielding resistance R
SX3Link be the negative output terminal U of second electric bridge
1 2 -, the 4th giant magnetoresistance R
X4With the 4th shielding resistance R
SX4Link be the positive output end U of second electric bridge
1 2 +The positive output end U of described first electric bridge
1+Link to each other the negative output terminal U of first electric bridge with the positive input terminal of second electric bridge
1-Link to each other with the negative input end of second electric bridge;
Y sensing unit 10 is used to measure the magnetic-field component on the Y direction, and the Y sensing unit is made up of the 3rd electric bridge and the 4th electric bridge, and described the 3rd electric bridge is by the 5th giant magnetoresistance R
Y1, the 5th the shielding resistance R
SY1, the 6th giant magnetoresistance R
Y2With the 6th shielding resistance R
SY2Form described the 5th giant magnetoresistance R
Y1, the 5th the shielding resistance R
SY1, the 6th giant magnetoresistance R
Y2With the 6th shielding resistance R
SY2End to end back forms bridge structure, described the 5th giant magnetoresistance R
Y1With the 6th shielding resistance R
SY2Link be the positive input terminal Vcc of the 3rd electric bridge, the 6th giant magnetoresistance R
Y2With the 5th shielding resistance R
Y1Link be the negative input end GND of the 3rd electric bridge, the 5th giant magnetoresistance R
Y1With the 5th shielding resistance R
SY1Link be the negative output terminal U of the 3rd electric bridge
2-, the 6th giant magnetoresistance R
Y2With the 6th shielding resistance R
SY2Link be the positive output end U of the 3rd electric bridge
2+Described the 4th electric bridge is by the 7th giant magnetoresistance R
Y3, the 7th the shielding resistance R
SY3, the 8th giant magnetoresistance R
Y4With the 8th shielding resistance R
SY4Form, described the 4th electric bridge is by the 7th giant magnetoresistance R
Y3, the 7th the shielding resistance R
SY3, the 8th giant magnetoresistance R
Y4With the 8th shielding resistance R
SY4End to end back forms bridge structure, described the 7th giant magnetoresistance R
Y3With the 8th shielding resistance R
SY4Link be the positive input terminal of the 4th electric bridge, the 8th giant magnetoresistance R
Y4With the 7th shielding resistance R
SY3Link be the negative input end of fourth stage electric bridge, the 7th giant magnetoresistance R
Y3With the 7th shielding resistance R
SY3Link be the negative output terminal U of the 4th electric bridge
2 2 -, the 8th giant magnetoresistance R
Y4With the 8th shielding resistance R
SY4Link be the positive output end U of the 4th electric bridge
2 2 +The positive output end U of described the 3rd electric bridge
2+Link to each other the negative output terminal U of the 3rd electric bridge with the positive input terminal of the 4th electric bridge
2-Link to each other with the negative input end of the 4th electric bridge;
The positive input terminal of the positive input terminal of first electric bridge of X sensing unit and the 3rd electric bridge of Y sensing unit is the anodal Vcc of same power supply, and the negative input end of the negative input end of first electric bridge of X sensing unit and the 3rd electric bridge of Y sensing unit is the negative pole GND of same power supply.
As shown in Figure 2, magnetic field sensor is made up of X sensing unit and Y sensing unit, and its sensitive axes is respectively X sensitive axes and Y sensitive axes, and two sensitive axes are mutually orthogonal.Each sensing unit all is made up of the two-stage bridge structure.The first order of X sensing unit is output as the differential mode output of first electric bridge, and its size is U
1=U
1+-U
1-, be directly proportional with magnetic field size on the X sensitive axes direction; The second level of X sensing unit is output as the differential mode output of second electric bridge, and its size is U
1 2=U
1 2 +-U
1 2 -, with square being directly proportional of magnetic field on X sensitive axes direction size.The first order of Y sensing unit is output as the differential mode output of the 3rd electric bridge, and its size is U
2=U
2+-U
2-, be directly proportional with magnetic field size on the Y sensitive axes direction; The second level of Y sensing unit is output as the differential mode output of the 4th electric bridge, and its size is U
2 2=U
2 2 +-U
2 2 -, with square being directly proportional of magnetic field on Y sensitive axes direction size.According to the directional sensitivity of giant magnetic resistor material, can calculate the intensity and the direction of plane inner field.
The sensor measurement magnetic direction that the present invention proposes and the principle of work of intensity are: giant magnetoresistance sensor is different for the sensitivity of the field signal of different directions, exists the maximum direction of sensitivity, is called sensitive axes.Along with the variation of the angle of magnetic direction and sensor sensing axle, sensitivity is along with angle demonstrates the rule of sinusoidal variations, and period of change is 360 °.As shown in Figure 3, any one externally-applied magnetic field can be decomposed into the stack in X sensitive axes direction and responsive axial two magnetic fields of Y.When measurement plane internal magnetic field signal, the voltage that the responsive axial magnetic field of X produces in the X of sensor sensing unit is for being U
1, the voltage that the responsive axial magnetic field of Y produces in the Y of sensor sensing unit is U
2, because U
1And U
2Quadrature, according to the character of sine, then the voltage that on sensor, produces of total magnetic field does
The direction indication in magnetic field is the angle theta of magnetic field and X sensitive axes, and its size is tan θ=U
2/ U
1The first order output of X sensing unit and Y sensing unit is respectively U
1And U
2, the second level output of X sensing unit and Y sensing unit is respectively U
1 2And U
2 2, can calculate the size of the voltage that magnetic field produces at an easy rate on sensor through the external arithmetic circuit
Direction tan θ=U with magnetic field
2/ U
1Because the output voltage of sensor is directly proportional with magnetic field intensity, so sensor can reflect magnetic field intensity.The advantage of this measuring method is to overcome effectively the problem of the angular-sensitive of sensor; Promptly when sensor generation wide-angle deflection; Quadrature arrangement through X sensing unit sensitive axes and Y sensing unit sensitive axes; Still can guarantee to measure the accuracy of magnetic field intensity, reflect the direction in magnetic field simultaneously.Related experiment result shows, when sensor rotated in 360 ° of two-dimensional spaces, its deviation was no more than 10%.
Giant magnetoresistance in the above-mentioned magnetic field sensor can be multiple layer metal membrane material or Spin Valve material, adopts the sputtering method preparation.Adopt photoetching method to form lead-in wire and electrode, power supply adopts Switching Power Supply or powered battery.