CN209927922U - Current detection device based on PCB - Google Patents
Current detection device based on PCB Download PDFInfo
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- CN209927922U CN209927922U CN201920322300.XU CN201920322300U CN209927922U CN 209927922 U CN209927922 U CN 209927922U CN 201920322300 U CN201920322300 U CN 201920322300U CN 209927922 U CN209927922 U CN 209927922U
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Abstract
The utility model discloses a current detection device based on PCB, one of them includes: a PCB body; the lead is printed on the first surface of the PCB body; the wire comprises a first straight wire and a second straight wire which are parallel to each other, and a third wire part connected with the first straight wire and the second straight wire from one side, wherein the third wire part is symmetrical relative to a symmetrical line which is parallel to the first straight wire and the second straight wire; the first magnetic resistor and the second magnetic resistor are arranged on the second surface of the PCB body; the projections of the first magnetic resistor and the second magnetic resistor on the plane where the wires are located are respectively located on the outer sides of the first straight wire and the second straight wire; the magnetic sensitivity directions of the first magnetic resistor and the second magnetic resistor are the same, and the first magnetic resistor and the second magnetic resistor are both parallel to the PCB body and vertical to the symmetry line; the first magnetic resistor and the second magnetic resistor are connected in series, and two ends of the first magnetic resistor and the second magnetic resistor are connected with a power supply after the first magnetic resistor and the second magnetic resistor are connected in series; and the input end of the signal processing module is connected between the first magneto resistor and the second magneto resistor. The device has higher precision when detecting smaller current to be detected.
Description
Technical Field
The utility model relates to a current sensor technical field, concretely relates to current detection device based on PCB.
Background
The current detection product is widely applied to the fields of new energy, intelligent traffic, industrial control, intelligent household appliances, intelligent power grids and the like. The current detection product is usually a packaged chip, at least two pins of the chip are respectively used for leading in or leading out current to be detected, and the two pins are also connected through a lead in the current detection chip; the magnetic sensor actually used for sensing the magnetic field to realize the function of detecting the current is also packaged in the chip, and the magnetic sensor is close to the lead wire connecting the two pins. The current detection chip has the following disadvantages: (1) the withstand voltage of the chip is low; (2) the sectional area of the wire for connecting the two pins is small, so that the internal resistance is large, the power consumption is large, and the chip type package makes the heat dissipation effect poor, so that the chip is easy to generate heat.
In order to solve the above drawbacks, the prior art provides a PCB-based current detection device, as shown in fig. 1A and 1B, such a current detection product includes a magnetic sensor 1, a wire 2 for passing a current to be detected, and a PCB board 3, wherein the magnetic sensor 1 and the wire 2 are respectively disposed on two opposite surfaces of the PCB board 3, and an "x" in the wire 2 indicates a direction of the current passing through the wire (i.e., from a paper surface or a screen side where a reader is located to the other side). Because the PCB 3 is arranged between the magnetic sensor 1 and the lead 2 as an interval, the magnetic field intensity sensed by the magnetic sensor 1 can be reduced under the condition that the current to be detected is not changed, the withstand voltage of a current detection product is improved, and the withstand voltage of the detection device can be further improved by adjusting the thickness and the size of the PCB. The lead 2 can be printed on the board body when the PCB is manufactured, the lead 2 is convenient to print in various shapes, the width of the cross section of the lead can be increased, so that the internal resistance of the lead is reduced, the power consumption of the lead is reduced, and the heat dissipation effect of the lead is better due to the fact that the printed heat dissipation surface of the lead is larger, so that the current detection device based on the PCB is less prone to heating.
However, the inventor found that the current detection device based on the PCB is suitable for measuring a large current (for example, a current of 30A or more), and the measurement accuracy is not sufficient for a small current (for example, a current of 30A or less).
Disclosure of Invention
In view of this, the embodiment of the present invention provides a current detection apparatus based on a PCB to solve the problem that the current measurement precision is not enough for the smaller current measurement method.
According to a first aspect, the embodiment of the utility model provides a current detection device based on PCB includes: a PCB body; the lead is printed on the first surface of the PCB body and used for being electrified with current to be measured; the wire comprises a first straight wire and a second straight wire which are parallel to each other, and a third wire part connected with the third wire part from one side, wherein the third wire part is symmetrical relative to a symmetrical line, and the symmetrical line is parallel to the first straight wire and the second straight wire and is basically equal to the distance between the first straight wire and the second straight wire; the first magnetic resistor and the second magnetic resistor are arranged on a second surface of the PCB body, and the second surface is opposite to the first surface; the projections of the first magnetic resistor and the second magnetic resistor on the plane where the wires are located are respectively located on the outer sides of the first straight wire and the second straight wire; the magnetic sensitivity directions of the first magnetic resistor and the second magnetic resistor are the same, and the first magnetic resistor and the second magnetic resistor are both parallel to the PCB body and perpendicular to the symmetry line; the first magnetic resistor and the second magnetic resistor are connected in series, and two ends of the first magnetic resistor and the second magnetic resistor are connected with a power supply after the first magnetic resistor and the second magnetic resistor are connected in series; and the input end of the signal processing module is connected between the first magnetic resistor and the second magnetic resistor and used for acquiring and outputting a current value to be detected according to an electric signal between the first magnetic resistor and the second magnetic resistor.
According to a second aspect, the embodiment of the present invention provides a current detection device based on PCB, including: a PCB body; the lead is printed on the first surface of the PCB body and used for being electrified with current to be measured; the wire comprises a first straight wire and a second straight wire which are parallel to each other, and a third wire part connected with the third wire part from one side, wherein the third wire part is symmetrical relative to a symmetrical line, and the symmetrical line is parallel to the first straight wire and the second straight wire and is basically equal to the distance between the first straight wire and the second straight wire; the first magnetic resistor, the second magnetic resistor, the third magnetic resistor and the fourth magnetic resistor are arranged on the second surface of the PCB body, and the second surface is opposite to the first surface; the projections of the first magnetic resistor and the fourth magnetic resistor on the plane where the wire is located are located on the same side of the outer portions of the first straight wire and the second straight wire, and the projections of the second magnetic resistor and the third magnetic resistor on the plane where the wire is located are located on the other side of the outer portions of the first straight wire and the second straight wire; the first magnetic resistor and the second magnetic resistor are connected in series, two ends of the first magnetic resistor and the second magnetic resistor are connected with a power supply, the third magnetic resistor and the fourth magnetic resistor are connected in series, two ends of the third magnetic resistor and the fourth magnetic resistor are connected with the power supply, and the first magnetic resistor and the third magnetic resistor are connected to the same end of the power supply; the projections of the two magneto resistors on the same series branch on the plane where the wire is located are respectively located on the outer sides of the first straight wire and the second straight wire; the magnetic sensitivity directions of the first magnetic resistor, the second magnetic resistor, the third magnetic resistor and the fourth magnetic resistor are the same, and the first magnetic resistor, the second magnetic resistor, the third magnetic resistor and the fourth magnetic resistor are all parallel to the PCB body and are perpendicular to the symmetry line; the first input end of the signal processing module is connected between the first magneto resistor and the second magneto resistor, and the second input end of the signal processing module is connected between the third magneto resistor and the fourth magneto resistor; the signal processing module is used for obtaining a current value to be measured according to the electric signal between the first magnetic resistor and the second magnetic resistor and the electric signal between the third magnetic resistor and the fourth magnetic resistor.
Optionally, the third wire portion is rectangular or rounded rectangular with an opening, and a long side of the rectangle is perpendicular to the line of symmetry.
Optionally, the third wire portion is a straight wire perpendicular to the symmetry line; and the first magnetic resistor and the second magnetic resistor are positioned on the same side of a central line of the first straight conducting wire or the second straight conducting wire.
Optionally, the lead further comprises: and the fourth straight conducting wire and the fifth straight conducting wire are perpendicular to the symmetry line and are respectively connected to the end parts of the first straight conducting wire and the second straight conducting wire.
Optionally, the signal processing module is an operational amplifier.
Optionally, the device comprises at least three detection cells, which comprise respective magnetoresistors and the conductive lines.
Optionally, at least three of the conductors are each adapted to be energized with a three-phase current.
Optionally, the device further comprises a metal cover disposed on the second surface of the PCB board, and each of the magneto resistors and/or the signal processing module is located in the metal cover.
The embodiment of the utility model provides a current detection device based on PCB, to the electric current that awaits measuring of the same size, the output value is bigger, and the precision is higher when detecting the less electric current that awaits measuring.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1A illustrates a side view of a prior art PCB-based current sensing device;
FIG. 1B is a schematic diagram illustrating the general structure of a conventional PCB-based current sensing apparatus;
fig. 2 shows a side view of a PCB-based current sensing apparatus according to an embodiment of the present invention;
fig. 3A illustrates a top view of a PCB-based current sensing device in accordance with an embodiment of the present invention;
fig. 3B illustrates a top view of another PCB-based current sensing device in accordance with an embodiment of the present invention;
FIG. 4 shows the electrical connection relationship of two magnetoresistors of FIGS. 2, 3A, 3B;
FIG. 5 is a schematic diagram showing electrical connections for an operational amplifier suitable for use in FIG. 4;
fig. 6 illustrates a side view of another PCB-based current sensing apparatus according to an embodiment of the present invention;
fig. 7A illustrates a top view of yet another PCB-based current detection apparatus in accordance with an embodiment of the present invention;
fig. 7B shows a top view of yet another PCB-based current detection apparatus according to an embodiment of the present invention;
FIG. 8 shows the electrical connection relationship of two magnetoresistors of FIGS. 6, 7A, 7B;
FIG. 9 is a schematic diagram showing electrical connections for an operational amplifier suitable for use in FIG. 8;
fig. 10 shows a schematic diagram of a PCB-based current detection apparatus including three detection units and respectively for applying three-phase currents.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present invention.
Note that the magnetic sensitivity direction in the present application is a direction vector, and includes "a direction in which a positive output value of the magnetic sensor increases when a magnetic field in the direction increases (also referred to as a positive magnetic sensitivity direction)" and "a direction in which a positive output value of the magnetic sensor decreases when a magnetic field in the direction increases (also referred to as a negative magnetic sensitivity direction)".
The present application also provides for: when only the magnetic sensitivity direction is mentioned, the magnetic sensitivity direction comprises a positive magnetic sensitivity direction and a negative magnetic sensitivity direction, and the positive direction and the negative direction are not distinguished; when the magnetic sensitivity directions are the same and opposite, the positive magnetic sensitivity direction and the negative magnetic sensitivity direction are distinguished, that is, the magnetic sensitivity directions are the same, namely the magnetic sensitivity directions are the positive magnetic sensitivity directions or the negative magnetic sensitivity directions, and the magnetic sensitivity directions are opposite, namely one is the positive magnetic sensitivity direction and the other is the negative magnetic sensitivity direction.
Example one
The embodiment of the utility model provides a current detection device based on PCB, figure 2 shows its side view, and figure 3A shows one of them top view, and figure 3B shows another kind of top view thereof, and wherein, the bar region of packing represents the wire, and inside dotted arrow indicates the current flow direction. The device comprises a first magneto resistor 11, a second magneto resistor 12, a conducting wire 20, a PCB board body 30 and a signal processing module (not shown in FIGS. 2, 3A and 3B).
The conductive traces 20 are printed on a first surface of the PCB board 30 for passing a current to be measured. The wire 20 includes a first straight wire and a second straight wire (i.e., two straight wires within a circular dashed box in fig. 3A and 3B) parallel to each other, and a third wire portion (i.e., a wire within a left rectangular dashed box in fig. 3A and 3B) connected thereto from one side, the third wire portion being symmetrical with respect to a symmetrical line that is parallel to and substantially equidistant from the first straight wire and the second straight wire.
The first magnetic resistor 11 and the second magnetic resistor 12 are arranged on a second surface of the PCB body 30, and the second surface is opposite to the first surface. The projections of the first and second magnetoresistive elements 11, 12 onto the plane of the conductor 20 are located outside the first and second straight conductor, respectively. In the present application, the first straight conductive wire and the second straight conductive wire are considered as a whole, and the "inner side of the first straight conductive wire and the second straight conductive wire" means between the two straight conductive wires, and the "outer side" of the first straight conductive wire and the second straight conductive wire is opposite to the "inner side". The first magneto resistor 11 and the second magneto resistor 12 are connected in series, and two ends of the series are connected with a power supply.
The input end of the signal processing module is connected between the first magneto resistor 11 and the second magneto resistor 12 and used for obtaining and outputting a current value to be measured according to an electric signal between the first magneto resistor 11 and the second magneto resistor 12.
Let R be the first magneto-resistance 111＝R0+k·B1Wherein R is0The resistance value of the first magneto resistor 11 when the magnetic induction is zero, B1K is the magnetic induction intensity at which the first magneto resistor 11 is located, and k is the change rate of the first magneto resistor 11; second magnetoresistive layer 12 has a resistance value of R2＝R0+k·B2Wherein R is0The resistance value of the second magnetic resistor 12 when the magnetic induction intensity is zero (when the magnetic induction intensity is zero, the resistance values of the first magnetic resistor 11 and the second magnetic resistor 12 are equal), B2K is the magnetic induction at which the second magnetoresistive 12 is located, and k is the rate of change of the second magnetoresistive 12. The voltage between the first magnetoresistive 11 and the second magnetoresistive 12 is then
The voltage between first magnetoresistive element 11 and second magnetoresistive element 12 should be V when no current is conducted in the line0＝Vcc/2. Therefore, after power-on, a voltage V is output between first magnetoresistive 11 and second magnetoresistive 120The difference of (d) is:
it should be noted that in the last step of the derivation of the above formula (1), R is actually used0The value of (A) is often much larger than that of (B)1And B2Of (2), thus 2R0+k·(B1+B2) Can be approximated to 2R0Thereby obtaining the final result of the above formula (1).
As can be seen from the final result of the above equation (1), the current value to be measured can be obtained according to the difference between the voltage value output between the first magnetoresistance 11 and the second magnetoresistance 12 and the reference value, and the output result of the current to be measured depends on the difference between the magnetic induction intensities at the positions of the first magnetoresistance 11 and the second magnetoresistance 12.
As shown in fig. 3A and 3B, since the directions of the currents flowing in the first straight conductive wire and the second straight conductive wire are opposite, the directions of the magnetic fields generated by the first straight conductive wire and the second straight conductive wire are opposite. Assuming that the first magnetoresistive layer 11 is closer to the first straight conductive line and the second magnetoresistive layer 12 is closer to the second straight conductive line, the "combined magnetic field of the straight conductive lines" at the positions where the first magnetoresistive layer 11 and the second magnetoresistive layer 12 are located should be located in the z-axis direction (z-axis direction, i.e., in the plane of the conductive lines and perpendicular to the line of symmetry) shown in the drawings and in the opposite direction, as shown in fig. 3A and 3B. Since the third wire portion is symmetrical with respect to the symmetry line, the magnetic fields generated by the portion of the third wire portion (i.e., the wire in the x-axis direction within the left-side rectangular dashed frame in fig. 3A and 3B) having a component in the z-axis direction at the positions of the first magnetoresistive 11 and the second magnetoresistive 12 are equal in magnitude and opposite in direction, and the sum of the vectors of the two is 0.
According to the above analysis, in the above formula (1), the magnetic induction B1And B2Is opposite, and the final result of equation (1) depends only on B1And B2The sum of the values of (i.e. | B)1|+|B2|), the produced magnetic field of third wire portion can not influence the final result of equation (1), consequently, to the electric current that awaits measuring of the same size, the embodiment of the utility model provides a current detection device based on PCB's output value is bigger, and the precision is higher when detecting less electric current that awaits measuring.
Let b be the magnetic induction of the magnetic field generated by the first and second straight conductive lines at the position of the first magneto resistor 111(b1Is a numerical value) and the magnetic induction at the location of the second magneto resistor 12 is-b2(b2Is a numerical value), the magnetic induction intensity of the external interference magnetic field at the positions of the first magnetic resistor 11 and the second magnetic resistor 12 is b0(i.e., common mode interference), the vector B1＝b1+b0，B2＝-b2+b0The difference B of the two vectors2＝b1-b2I.e. the detection result is not affected by common mode interference. Therefore, the embodiment of the utility model provides a PCB-based current detection device can be resisted external magnetic field and disturbedThe strength is strong.
It should be noted that the reference value may be selected to be half of the value of the power supply voltage, or may be other fixed values. The signal processing module for obtaining the current value to be measured according to the difference between the voltage value output between the first magnetoresistance 11 and the second magnetoresistance 12 and the reference value may be an operational amplifier and its peripheral circuits, as shown in fig. 4 and 5, a first input terminal of the operational amplifier is connected between the first magnetoresistance 11 and the second magnetoresistance 12, a second input terminal is connected to the reference voltage, in the figure, VoIs the voltage between the first 11 and second 12 magnetoresistive resistor, VrefFor the reference voltage, it may be set to a half value of the power supply voltage, i.e., V cc2; alternatively, the module may be a module including a processor chip, or may be other electronic circuits, and the present application is not limited thereto.
Example two
The embodiment of the utility model provides another kind of current detection device based on PCB, its side view is shown in figure 6, and one kind of top view is shown in figure 7A, and another kind of top view is shown in figure 7B. As can be seen from a comparison of fig. 2, fig. 3A and fig. 3B, the device provided by the embodiment of the present invention is different from the first embodiment in that the device includes four magnetoresistors, i.e., a first magnetoresistive 11, a second magnetoresistive 12, a third magnetoresistive 13 and a fourth magnetoresistive 14, instead of two magnetoresistors. The specific arrangement of these four magnetoresistors in this embodiment will be described in detail below.
First magnetic resistance 11, second magnetic resistance 12, third magnetic resistance 13, fourth magnetic resistance 14 set up in the second surface of PCB plate body 30, and the second surface is relative with the first surface. The projections of the first magnetic resistor 11 and the fourth magnetic resistor 14 on the plane of the wire 20 are located on the same side of the outer portions of the first straight wire and the second straight wire, and the projections of the second magnetic resistor 12 and the third magnetic resistor 13 on the plane of the wire 20 are located on the other side of the outer portions of the first straight wire and the second straight wire. In the present application, the first straight conductive wire and the second straight conductive wire are considered as a whole, and the "inner side of the first straight conductive wire and the second straight conductive wire" means between the two straight conductive wires, and the "outer side" of the first straight conductive wire and the second straight conductive wire is opposite to the "inner side". First magnetism resistance 11 and second magnetism resistance 12 are established ties, and the power is connected at the both ends after establishing ties, and third magnetism resistance 13 and fourth magnetism resistance 14 are established ties, and the power is connected at the both ends after establishing ties to first magnetism resistance 11 and third magnetism resistance 13 are connected to the same end of power. The projections of the two magnetoresistors on the same series branch on the plane of the lead 20 are respectively positioned at the outer sides of the first straight lead and the second straight lead, for example, the projections of the first magnetoresistor 11 and the second magnetoresistor 12 on the plane of the lead 20 are respectively positioned at the outer sides of the first straight lead and the second straight lead, and the projections of the third magnetoresistor 13 and the fourth magnetoresistor 14 on the plane of the lead 20 are respectively positioned at the outer sides of the first straight lead and the second straight lead. The magnetic sensitivity directions of the first magnetic resistor 11, the second magnetic resistor 12, the third magnetic resistor 13 and the fourth magnetic resistor 14 are the same, and are parallel to the PCB body 30 and perpendicular to the symmetry line.
A first input end of the signal processing module is connected between the first magneto resistor 11 and the second magneto resistor 12, and a second input end of the signal processing module is connected between the third magneto resistor 13 and the fourth magneto resistor 14; the signal processing module is used for obtaining a current value to be measured according to an electric signal between the first magneto resistor 11 and the second magneto resistor 12 and an electric signal between the third magneto resistor 13 and the fourth magneto resistor 14.
As shown in fig. 8, the first branch in which the first magnetoresistive element 11 and the second magnetoresistive element 12 are located can be separately regarded as the circuit shown in fig. 4, and the second branch in which the third magnetoresistive element 13 and the fourth magnetoresistive element 14 are located can also be separately regarded as the circuit shown in fig. 4. Since the magnetic field directions at the positions of the first magnetic resistor 11 and the fourth magnetic resistor 14 are the same, the magnetic field directions at the positions of the second magnetic resistor 12 and the third magnetic resistor 13 are the same, the magnetic field directions at the positions of the first magnetic resistor 11 and the second magnetic resistor 12 are opposite, and the magnetic sensitivity directions of the four magnetic resistors are the same, when no current is conducted in a wire, the values of V- (namely the voltage between the first magnetic resistor 11 and the second magnetic resistor 12) and V + (namely the voltage between the third magnetic resistor 13 and the fourth magnetic resistor 14) in the wire are the same, and the difference between the values is 0; when current is passed through the wire, V-and V + in FIG. 8 change in opposite directions (i.e., one increases and the other decreases), respectively, by twice the amount of change in either. Therefore, compared with the first embodiment, the current detection device provided by the present embodiment can further increase the output value and improve the detection accuracy.
Similar to the first embodiment, the signal processing module can be an operational amplifier and its peripheral circuits, as shown in fig. 8 and 9 (the positions with the same symbols in the two figures are electrically connected); alternatively, the module may be a module including a processor chip, or may be other electronic circuits, and the present application is not limited thereto.
As an alternative to the first or second embodiment, the third wire portion is a rectangle with an opening or a rounded rectangle, and the long side of the rectangle is perpendicular to the line of symmetry, as shown in the dashed box of the left rectangle in fig. 3A or fig. 7A.
As an alternative to the first or second embodiment, the third conducting portion is a straight conducting line perpendicular to the symmetry line, as shown in the left rectangular dashed box in fig. 3B or fig. 7B; and the first magneto resistor 11 and the second magneto resistor 12 are located on the same side of the center line of the first straight wire or the second straight wire. In this embodiment, the first straight conductive wire and the second straight conductive wire are long, and the specific length needs to be determined according to actual conditions.
As an alternative to the first embodiment or the second embodiment, the wire 20 further includes a fourth straight wire and a fifth straight wire, both perpendicular to the symmetry line and connected to the ends of the first straight wire and the second straight wire, respectively, as shown in fig. 3A, 3B, 7A, and 7B.
As an optional implementation manner of the first embodiment or the second embodiment, the PCB-based current detection apparatus includes at least three detection units, each detection unit includes the respective magnetoresistance and conductive wires described in the first embodiment or the second embodiment, so that a plurality of detection units are disposed on one PCB, and each detection unit can be used to detect one path of current to be detected. In particular, at least three lines can be used for supplying a three-phase current. For example, in fig. 10, filled bar regions represent conductive lines, three conductive lines are used for A, B, C three-phase current, two small squares near each conductive line represent two magnetoresistors, and 30 represents a PCB board.
As an optional implementation manner of the first embodiment or the second embodiment, the PCB-based current detection apparatus further includes a metal cover disposed on the second surface of the PCB, and each of the magneto-resistive and/or signal processing modules is located in the metal cover. The metal cover can shield the interference of an external electric field, and effectively eliminates the interference of the current to be measured (namely the interference of dv/dt to the magnetoresistance) and the interference of a space stray electric field to each component of the magnetoresistance or signal processing module.
Optionally, the magnetoresistance in the embodiments of the present application may adopt a TMR tunneling magnetoresistance with higher sensitivity and higher accuracy, or other similar magnetoresistance, which is not limited in the present application.
Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations fall within the scope defined by the appended claims.
Claims (14)
1. A PCB-based current sensing device, comprising:
a PCB body;
the lead is printed on the first surface of the PCB body and used for being electrified with current to be measured; the wire comprises a first straight wire and a second straight wire which are parallel to each other, and a third wire part connected with the third wire part from one side, wherein the third wire part is symmetrical relative to a symmetrical line, and the symmetrical line is parallel to the first straight wire and the second straight wire and is basically equal to the distance between the first straight wire and the second straight wire;
the first magnetic resistor and the second magnetic resistor are arranged on a second surface of the PCB body, and the second surface is opposite to the first surface; the projections of the first magnetic resistor and the second magnetic resistor on the plane where the wires are located are respectively located on the outer sides of the first straight wire and the second straight wire; the magnetic sensitivity directions of the first magnetic resistor and the second magnetic resistor are the same, and the first magnetic resistor and the second magnetic resistor are both parallel to the PCB body and perpendicular to the symmetry line; the first magnetic resistor and the second magnetic resistor are connected in series, and two ends of the first magnetic resistor and the second magnetic resistor are connected with a power supply after the first magnetic resistor and the second magnetic resistor are connected in series;
and the input end of the signal processing module is connected between the first magnetic resistor and the second magnetic resistor and used for acquiring and outputting a current value to be detected according to an electric signal between the first magnetic resistor and the second magnetic resistor.
2. The PCB-based current detection device according to claim 1, wherein the third wire part is rectangular or rounded rectangular with an opening, and a long side of the rectangle is perpendicular to the line of symmetry.
3. The PCB-based current sensing device of claim 1, wherein the third wire portion is a straight wire perpendicular to the line of symmetry; and the first magnetic resistor and the second magnetic resistor are positioned on the same side of a central line of the first straight conducting wire or the second straight conducting wire.
4. The PCB-based current sensing device of claim 1, wherein the conductive trace further comprises:
and the fourth straight conducting wire and the fifth straight conducting wire are perpendicular to the symmetry line and are respectively connected to the end parts of the first straight conducting wire and the second straight conducting wire.
5. The PCB-based current sensing device of claim 1, wherein the signal processing module is an operational amplifier.
6. The PCB-based current sensing device of claim 1, comprising at least three sensing cells, the sensing cells comprising respective magnetoresistors and the conductive wires.
7. The PCB-based current sensing device of claim 1, further comprising a metal cover disposed on the second surface of the PCB board, and wherein each of the magneto-resistive and/or the signal processing modules is located within the metal cover.
8. A PCB-based current sensing device, comprising:
a PCB body;
the lead is printed on the first surface of the PCB body and used for being electrified with current to be measured; the wire comprises a first straight wire and a second straight wire which are parallel to each other, and a third wire part connected with the third wire part from one side, wherein the third wire part is symmetrical relative to a symmetrical line, and the symmetrical line is parallel to the first straight wire and the second straight wire and is basically equal to the distance between the first straight wire and the second straight wire;
the first magnetic resistor, the second magnetic resistor, the third magnetic resistor and the fourth magnetic resistor are arranged on the second surface of the PCB body, and the second surface is opposite to the first surface; the projections of the first magnetic resistor and the fourth magnetic resistor on the plane where the wire is located are located on the same side of the outer portions of the first straight wire and the second straight wire, and the projections of the second magnetic resistor and the third magnetic resistor on the plane where the wire is located are located on the other side of the outer portions of the first straight wire and the second straight wire; the first magnetic resistor and the second magnetic resistor are connected in series, two ends of the first magnetic resistor and the second magnetic resistor are connected with a power supply, the third magnetic resistor and the fourth magnetic resistor are connected in series, two ends of the third magnetic resistor and the fourth magnetic resistor are connected with the power supply, and the first magnetic resistor and the third magnetic resistor are connected to the same end of the power supply; the projections of the two magneto resistors on the same series branch on the plane where the wire is located are respectively located on the outer sides of the first straight wire and the second straight wire; the magnetic sensitivity directions of the first magnetic resistor, the second magnetic resistor, the third magnetic resistor and the fourth magnetic resistor are the same, and the first magnetic resistor, the second magnetic resistor, the third magnetic resistor and the fourth magnetic resistor are all parallel to the PCB body and are perpendicular to the symmetry line;
the first input end of the signal processing module is connected between the first magneto resistor and the second magneto resistor, and the second input end of the signal processing module is connected between the third magneto resistor and the fourth magneto resistor; the signal processing module is used for obtaining a current value to be measured according to the electric signal between the first magnetic resistor and the second magnetic resistor and the electric signal between the third magnetic resistor and the fourth magnetic resistor.
9. The PCB-based current detection device according to claim 8, wherein the third wire part is rectangular or rounded rectangular with an opening, and a long side of the rectangle is perpendicular to the line of symmetry.
10. The PCB-based current sensing device of claim 8, wherein the third wire portion is a straight wire perpendicular to the line of symmetry; and the first magnetic resistor and the second magnetic resistor are positioned on the same side of a central line of the first straight conducting wire or the second straight conducting wire.
11. The PCB-based current sensing device of claim 8, wherein the conductive trace further comprises:
and the fourth straight conducting wire and the fifth straight conducting wire are perpendicular to the symmetry line and are respectively connected to the end parts of the first straight conducting wire and the second straight conducting wire.
12. The PCB-based current sensing device of claim 8, wherein the signal processing module is an operational amplifier.
13. The PCB-based current sensing device of claim 8, comprising at least three sensing cells, the sensing cells comprising respective magnetoresistors and the conductive wires.
14. The PCB-based current sensing device of claim 8, further comprising a metal cover disposed on the second surface of the PCB board, and wherein each of the magneto-resistive and/or the signal processing modules is located within the metal cover.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920322300.XU CN209927922U (en) | 2019-03-13 | 2019-03-13 | Current detection device based on PCB |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920322300.XU CN209927922U (en) | 2019-03-13 | 2019-03-13 | Current detection device based on PCB |
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| Publication Number | Publication Date |
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| CN209927922U true CN209927922U (en) | 2020-01-10 |
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