CN103913609A

CN103913609A - Measurement instrument free from effects of alternating external magnetic field and realization method thereof

Info

Publication number: CN103913609A
Application number: CN201210591292.1A
Authority: CN
Inventors: 胡明智; 蔡方辉; 马向阳; 程正忠
Original assignee: SHENZHEN HAONINGDA INSTRUMENT CO Ltd
Current assignee: Guangdong Haoning Da Industrial Co ltd
Priority date: 2012-12-31
Filing date: 2012-12-31
Publication date: 2014-07-09
Anticipated expiration: 2032-12-31
Also published as: CN103913609B

Abstract

The invention proposes a measurement instrument free from effects of an alternating external magnetic field and a realization method thereof. The measurement instrument includes signal acquisition copper-covered leads which are connected to printed circuit board of an integrated circuit, a current sampling resistor made of a manganese copper alloy material and current sampling wires. The two current sampling wires are closely twisted into a sampling line alternatively. The vector sum of an areas defined by annular current circuits formed by a first end part of the sampling line and the two current leads is zero. The vector sum of areas defined by annular current circuits formed by a second end part of the sampling line and the current sampling resistor is zero. Through improvement of a wiring method and a wiring structure, current circuit areas which can be subjected to action of the external alternating magnetic field are reduced or even offset so that the vector sum of inductive voltages in the alternating magnetic field is zero and thus effects of the external alternating magnetic field on a current sampling module are reduced significantly or even offset completely.

Description

Measurement instrument and its implementation of not affected by alternation external magnetic field

Technical field

The present invention relates to prevent that the measurement instrument of method and application the method for misreading several situations from appearring in measurement instrument, particularly relate to and prevent that the measurement instrument with current sample module from producing induction current because affected by outside alternating magnetic field, cause the improper electric current of measurement instrument to show or the method for counting and the measurement instrument of application the method.

Background technology

The Typical Representative with the measurement instrument of current sample module is electric energy meter, or power meter, also comprise the measurement instrument of some special measurement objects, for example only need to measure the reometer of current data, current data and other data need to be combined to measurement instrument of measurement etc., these measurement instruments are owing to all current signal being carried out to sampled measurements, thereby be all provided with the separate modular for completing current sample, or there is the comprehensively sampling module of current sample functional module, the present invention is referred to as this type of measurement instrument the measurement instrument with current sample module.Measurement instrument will be subject to actual motion environmental impact and occurring affecting the situation of accuracy of measurement in the time that reality is used.For the measurement instrument with current sample module, if operated in the environment with outside alternating magnetic field, the external magnetic field of alternation will make in the current sample module in measurement instrument and produce induction current.Described outside alternating magnetic field may come near power equipment, the line of electric force etc. measurement instrument.In the time of normal measurement, the induction current that affected by outside alternating magnetic field and to produce affects actual measured results and is difficult for realizing, but when measurement instrument is not in the situation that there is no sampled measurements, the induction current that is subject to outside alternating magnetic field to affect generation also will be gathered by current sample module, and induction current is counted to actual measured results, cause measurement instrument in the time of energising, but without measuring under current conditions, the measurement instrument of electronic type and measurement current module are affected by outside alternating magnetic field, and the improper electric current causing shows or counting, this kind of situation is called as shunt running phenomenon for power measuring instrument.

Can embody quantitatively by test the improper electric weight counting that described outside alternating magnetic field causes, as shown in Figure 9, with ZHZ-26A type alternating current impression influence of magnetic field test unit, TD8600E type teslameter, three-phase electric energy program control test device is test unit, the single-phase charge-controlled intelligent electric meter described conduct to the measurement instrument 9 of current sample module applies respectively directions X, the 0.5mT of Y-direction and Z direction, the i.e. alternating magnetic field of 0.5 milli tesla, record and be subject to directions X 0.5mT alternating magnetic field to affect the induction current that produces 24mA in current sample module, be subject to Y-direction 0.5mT alternating magnetic field to affect the induction current that produces 38mA in current sample module, be subject to Z direction 0.5mT alternating magnetic field to affect the induction current that produces 0mA in current sample module.From above-mentioned test, affected by outside alternating magnetic field, described measurement instrument is in the time of energising, but without measuring under current conditions, the measurement instrument of electronic type and measurement current module are affected by outside alternating magnetic field, and the improper electric current causing shows or counting phenomenon, or shunt running phenomenon exists really.

Be commonly used in family and industrial user taking the single-phase charge-controlled intelligent electric meter that uses in described test as the electricity tariff meter of representative, well imagine that described shunt running phenomenon obviously will cause unnecessary economic loss to electricity tariff meter user.It is inaccurate that the shunt running producing so affected by outside alternating magnetic field not only can make all measurement instruments with current sample module measure, and the defect that its performance is given prominence to the most, had the greatest impact is exactly to bring unnecessary economic loss to the user of family expenses or industrial Changeable electric meter.

Summary of the invention

The technical problem to be solved in the present invention is to avoid the deficiencies in the prior art part and proposes a kind of measurement instrument that prevents from having current sample module and be subject to outside alternating magnetic field and occur that improper electric current shows or the method for counting phenomenon, and the measurement instrument with current sample module of application the method.The present invention is according to the faradic principle of inducting, by improving the mode of connection and wiring construction, significantly reduce the ring current area that loop surrounds of the hard to bear action of alternating magnetic field of the interior energy of cancellation current sampling module even completely, thereby suppress the impact of outside alternating magnetic field on current sample module.

The present invention solve the technical problem can be by realizing by the following technical solutions:

Design, manufacture a kind of measurement instrument with current sample module that not affected by alternation external magnetic field, comprise signals collecting printed circuit board (PCB), the current sampling resistor device made from manganin material, and be connected electrically in two current sample wires between described signals collecting printed circuit board (PCB) and current sampling resistor device.Described signals collecting printed circuit board (PCB) comprises signal processing chip and two current feeds.By described two current feeds, signal processing chip is electrically connected with described two current sample wires.Especially, described two current sample wires are spiral ring and are closely alternately twisted into a sampling cotton rope with first end and the second end.Two current sample wires of first end of described sampling cotton rope are electrically connected described signals collecting printed circuit board (PCB), and the area vector sum that makes the ring current loop of two current sample wires of this first end and two current feeds composition surround is zero.Two current sample wires of the second end of described sampling cotton rope are electrically connected described current sampling resistor device, and the area vector sum that the ring current loop that makes the current return of two current sample wires of this second end and current sampling resistor device form surrounds is zero.Described area vector refers to the directive area of plane of the tool being surrounded by ring current loop, and the direction of described area vector is determined according to the direction of current in the ring current loop that surrounds plane.

Particularly, the direction of described area vector is pressed right-hand rule and is determined, with the right hand clench fist, thumb central axis by other four finger round and thumb to the right fist stretch out outward and the cylindrical coordinates that forms is basis, in the time that other four finger of the right hand is clenched fist by the direction of current in ring current loop, the sensing of thumb is exactly the direction of the area vector that surrounds of ring current loop.

The scheme that a kind of cotton rope of sampling is electrically connected with signals collecting printed circuit board (PCB), two current sample wires of first end of described sampling cotton rope are electrically connected respectively two current feeds of described printed circuit board (PCB), and wherein the bending of a current sample wire is semicircular and is arranged in printed circuit board (PCB), make this root bending be the annulus area equal and opposite in direction that annulus area that Semicircular current sample wire surrounds and two current feeds surround, area vector opposite direction, thereby the area vector sum that makes the ring current loop of two current sample wires of described first end and two current feeds composition surround is zero.

Particularly, on described signals collecting printed circuit board (PCB), be provided with collection signal connection end point.Described signals collecting chip comprises two current acquisition pins.Described two current feeds are the two current feed wires that wrapping the epidermis that insulate, and this two current feeds wire is connected electrically in respectively between the two current acquisition pins and two collection signal connection end points of signals collecting chip.Or described two current feeds are the two P.e.c. current feeds that are printed on signals collecting printed circuit board (PCB), this two P.e.c. current feed is connected electrically in respectively between the two current acquisition pins and two collection signal connection end points of signals collecting chip.

The scheme that another kind of sampling cotton rope be electrically connected with signals collecting printed circuit board (PCB), the mutual nothing of described two current feeds be electrically connected ground connection, be arranged on printed circuit board (PCB) across.Two current sample wires of first end of described sampling cotton rope are electrically connected respectively two current feeds of described printed circuit board (PCB), between the current sample wire that order is electrically connected and current feed, surround at least one pair of ring current loop by the point of crossing of two current feeds, and the annulus area equal and opposite in direction that described ring current loop surrounds, area vector opposite direction, thus the area vector sum that makes the ring current loop of two current sample wires of described first end and two current feeds composition surround is zero.

Particularly, on described signals collecting printed circuit board (PCB), be provided with two collection signal connection end points, and a wire through-hole.Described two current feeds by this wire through-hole mutually without the ground connection that is electrically connected, be arranged on printed circuit board (PCB) across.Described signals collecting chip comprises two current acquisition pins.Described two current feeds are the two current feed wires that wrapping the epidermis that insulate, this two current feeds wire is connected electrically in respectively between the two current acquisition pins and two collection signal connection end points of signals collecting chip, and by described wire through-hole mutually without the ground connection that is electrically connected, be arranged on printed circuit board (PCB) across.Or, one in described two current feeds is the P.e.c. current feed being printed on signals collecting printed circuit board (PCB), another root is the two current feed wires that wrapping the epidermis that insulate, described P.e.c. current feed is connected electrically between the current acquisition pin and collection signal connection end point of signals collecting chip, described current feed wire through described wire through-hole and P.e.c. current feed without the ground connection that is electrically connected, arranged in a crossed manner on printed circuit board (PCB), and described current feed wire is connected electrically between the current acquisition pin and collection signal connection end point of signals collecting chip.

Another makes mutually electrical connection scheme arranged in a crossed manner of current feed, is provided with two collection signal connection end points on described signals collecting printed circuit board (PCB), and two conductive poles that run through described signals collecting printed circuit board (PCB).Described signals collecting chip comprises two current acquisition pins.Described two current feeds comprise current feed the first branch line and current feed the second branch line separately.Described two current feeds current feed the first branch line is separately separately positioned on the two sides of signals collecting printed circuit board (PCB), and be connected electrically between two conductive poles and two current acquisition pins, make two current feed the first branch lines without the ground connection that is electrically connected, arranged in a crossed manner on printed circuit board (PCB).Described two current feeds current feed the second branch line is separately separately positioned on the two sides of signals collecting printed circuit board (PCB), and be connected electrically between two conductive poles and two collection signal connection end points, make two current feed the second branch lines without the ground connection that is electrically connected, arranged in a crossed manner on printed circuit board (PCB).Thereby by two current feeds, two current acquisition pins of described signals collecting chip are electrically connected to described collection signal connection end point.Described two current feeds are the two current feed wires that wrapping the epidermis that insulate, or described two current feeds are the P.e.c. current feeds that are printed on signals collecting printed circuit board (PCB).

The scheme that a kind of cotton rope of sampling is electrically connected with current sampling resistor device, two current sample wires of the second end of described sampling cotton rope are electrically connected respectively described current sampling resistor device, and wherein a current sample wire attaches and is wrapped in current sampling resistor device surface, in the direction of the longitudinal section of current sampling resistor device, described in order, being wrapped in the current loop that the current sample wire on current sampling resistor device surrounds equates with the size that the ring current loop in current sampling resistor device surrounded separately, area vector opposite direction, the area vector sum that two current sample wires of the second end of described sampling cotton rope and the ring current loop of current sampling resistor device formation are surrounded is zero.

The scheme that another kind of sampling cotton rope is electrically connected with current sampling resistor device, two current sample wires of the second end of described sampling cotton rope are electrically connected respectively two links of described current sampling resistor device, two current sample wire furcations of described the second end are arranged on the position away from described two links on current sampling resistor, and be all attached to current sampling resistor device surface from two sections of current sample wires between two current sample wire furcation to two current sample wires of the second end and the link of current sampling resistor device, in the direction of the longitudinal section of current sampling resistor device, described in order, be attached to the ring current loop area equal and opposite in direction that the current return in current loop and the current sampling resistor device that the current sample wire on current sampling resistor device surrounds surrounds, area vector opposite direction, the area vector sum that makes two current sample wires of the second end of described sampling cotton rope and the ring current loop of current sampling resistor device formation surround is zero.

Particularly, described current sampling resistor device is the resistor made from manganin material.

Consider the measurement instrument that is applicable to generally use, described measurement instrument is the measurement instrument for measuring electric power, also comprise the voltage sample wire being connected electrically between described signals collecting printed circuit board (PCB) and current sampling resistor device, described two current sample wires, and voltage sample wire is spiral ring and is closely twisted into a sampling cotton rope with first end and the second end, be voltage sample wire stranding in sampling cotton rope, and be spiral ring with two current sample wires and closely twist together.

The present invention solve the technical problem can also be by realizing by the following technical solutions:

Implement the method that measurement instrument that a kind of order has current sample module is not affected by alternation external magnetic field, described measurement instrument comprises signals collecting printed circuit board (PCB), current sampling resistor device, and be connected electrically in two current sample wires between described signals collecting printed circuit board (PCB) and current sampling resistor device.Described signals collecting printed circuit board (PCB) comprises signal processing chip and two current feeds.By described two current feeds, signal processing chip is electrically connected with described two current sample wires.Described method comprises the steps:

A. two current sample wires are to spiral ring and are closely alternately twisted into a sampling cotton rope with first end and the second end;

B. two current sample wires of the first end of described sampling cotton rope are electrically connected to described collection printed circuit board (PCB), the ring current loop that current sample wire and current feed surround is set, and the area vector sum that makes the ring current loop of two current sample wires of this first end and two current feeds composition surround is zero;

C. two current sample wires of the second end of described sampling cotton rope are electrically connected to described current sampling resistor device, current return path when current sample wire is set is electrically connected with current sampling resistor device, the area vector sum that the ring current loop that makes the current return in two current sample wires of this second end and current sampling resistor device form surrounds is zero.

Particularly, described step B comprises as follows step by step,

B11. a current sample wire in the first end of described sampling cotton rope two current sample wires is electrically connected to a current feed of described printed circuit board (PCB);

B12. after another root current sample wire in the first end of described sampling cotton rope two current sample wires first being bent to semicircular in printed circuit board (PCB), be electrically connected again another root current feed;

B13. adjust the length that described bending is Semicircular current sample wire, make this root bending be the annulus area equal and opposite in direction that annulus area that Semicircular current sample wire surrounds and two current feeds surround, area vector opposite direction, thus the area vector sum that makes the ring current loop of two current sample wires of described first end and two current feeds composition surround is zero.

In addition, described step B can also comprise as follows step by step,

B21. by described two current feeds mutually without the ground connection that is electrically connected, be arranged on printed circuit board (PCB) across;

B22. two current sample wires of the first end of described sampling cotton rope are electrically connected respectively to two current feeds of described printed circuit board (PCB), thereby make between the current sample wire that is electrically connected and current feed and surround at least one pair of ring current loop by the point of crossing of two current feeds;

B23. adjust the position of the point of crossing of two current feeds, and the length of two current sample wires of first end of described sampling cotton rope, the size in two ring current loops that surround between the current sample wire that order is electrically connected and current feed equates, and area vector opposite direction, thereby the area vector sum that makes the ring current loop of two current sample wires of described first end and two current feeds composition surround is zero.

Particularly, described step C comprises as follows step by step,

C11. a current sample wire in two current sample wires of the second end of described sampling cotton rope is directly electrically connected to a link of described current sampling resistor device;

C12. another root current sample wire in two current sample wires of the second end of described sampling cotton rope is first attached and is wrapped in current sampling resistor device surface, then be electrically connected another link of current sampling resistor device;

B13. adjust the canoe that is wrapped in the current sample wire on current sampling resistor device, in the direction of the longitudinal section of current sampling resistor device, described in order, be wrapped in that the current loop that the current sample wire on current sampling resistor device surrounds equates with the size that the ring current loop in current sampling resistor device surrounded separately, area vector opposite direction, thereby the area vector sum that two current sample wires of the second end of described sampling cotton rope and ring current loop that current sampling resistor device forms are surrounded is zero.

In addition, described step C can also comprise as follows step by step,

C21. two current sample wires of the second end of described sampling cotton rope are electrically connected respectively to two links of described current sampling resistor device, two current sample wire furcations of described the second end are arranged on to the position away from described two links on current sampling resistor, and are all attached to current sampling resistor device surface from two sections of current sample wires between two current sample wire furcation to two current sample wires of the second end and the connection end point of current sampling resistor device;

C22. adjust from the length of two sections of current sample wires between two current sample wire furcation to two current sample wires of the second end and the connection end point of current sampling resistor device, in the direction of the longitudinal section of current sampling resistor device, described in order, be attached to the ring current loop area equal and opposite in direction that the current return in current loop and the current sampling resistor device that the current sample wire on current sampling resistor device surrounds surrounds, area vector opposite direction, the area vector sum that two current sample wires of the second end of described sampling cotton rope and the ring current loop of current sampling resistor device formation are surrounded is zero.

Compared with the existing technology, the present invention's " measurement instrument and its implementation of not affected by alternation external magnetic field " technique effect is:

The present invention is according to the faradic principle of inducting, by improving the mode of connection and wiring construction, utilize the directivity in the face territory, space taking current loop as border, reduce the current return area of even offsetting the hard to bear outside action of alternating magnetic field of energy, making its induced voltage vector at alternating magnetic field is zero, thereby significantly reduce and offset the impact of outside alternating magnetic field on current sample module even completely, substantially eliminate described measurement instrument because being subject to outside alternating magnetic field to affect the impact on current sample module.

Brief description of the drawings

Fig. 1 is the main schematic diagram of looking of orthogonal projection of the present invention's " measurement instrument and its implementation of not affected by alternation external magnetic field " the first embodiment;

Fig. 2 is that schematic diagram is looked on the orthogonal projection right side of described the first embodiment;

Fig. 3 is the main schematic diagram of looking of the orthogonal projection of second embodiment of the invention;

Fig. 4 is that schematic diagram is looked on the orthogonal projection right side of described the second embodiment;

Fig. 5 is the main schematic diagram of looking of orthogonal projection of the signals collecting printed circuit board (PCB) 1 of third embodiment of the invention;

Fig. 6 is the main schematic diagram of looking of orthogonal projection of the signals collecting printed circuit board (PCB) 1 of fourth embodiment of the invention;

Fig. 7 is the main schematic diagram of looking of orthogonal projection of the signals collecting printed circuit board (PCB) 1 of fifth embodiment of the invention;

Fig. 8 be area vector of the present invention based on the schematic diagram of cylindrical coordinate system;

Fig. 9 is the Distribution of Magnetic Field schematic diagram of external magnetic field on measurement instrument impact test;

Figure 10 is the main schematic diagram of looking of the orthogonal projection of prior art measurement instrument;

Figure 11 is that schematic diagram is looked on the orthogonal projection right side of prior art measurement instrument.

Embodiment

Be described in further detail below in conjunction with each embodiment shown in accompanying drawing.

The present invention program further eliminates shunt running test taking described test above and puts into practice as basis, therefore describe technical solution of the present invention and every embodiment in detail below in conjunction with conclusion (of pressure testing).

As shown in Figure 10 and Figure 11, the measurement instrument that prior art has a current sample module all at least comprise signals collecting printed circuit board (PCB) 1 ', current sampling resistor device 3 ', and for be electrically connected described signals collecting printed circuit board (PCB) 1 ' with current sampling resistor device 3 ' two current sample wires 21 ', 22 '.Signals collecting printed circuit board (PCB) 1 ', current sampling resistor device 3 ' and current sample wire 21 ', 22 ' form the current sample module of measurement instrument.Described signals collecting printed circuit board (PCB) 1 ' at least should be provided with signal processing chip 13 ', and for settling signal process chip 13 ' with current sample wire 21 ', the 22 ' current feed 11 that is electrically connected ', 12 '.Have the test of shunt running phenomenon above according to the measurement instrument described in confirming with current sample module, as shown in Figure 8, in the time applying the outside alternating magnetic field of 0.5mT of X-direction, the electric current recording in current sample module is 24mA; In the time applying the outside alternating magnetic field of 0.5mT of Y direction, the electric current recording in current sample module is 38mA; In the time applying the outside alternating magnetic field of 0.5mT of Z-direction, the electric current recording in current sample module is 0mA.In current sample module, produce induction current and just certainly lead to induction electromotive force, according to faraday's law of magnetic induction, the size of induction electromotive force E is directly proportional to the flux change rate ΔΦ in magnetic field,

E＝n×ΔΦ/Δt，

Wherein n is the solenoid number of turn that produces magnetic field, and Δ t refers to the magnetic fields time period.And magnetic flux Φ and magnetic field intensity B, and the area S that the current loop of magnetic fields surrounds is relevant,

ΔΦ＝ΔB×ΔS。

Can obtain according to above-mentioned two equatioies,

E＝n×ΔB×ΔS/Δt。

In spatial domain, area that the current loop of magnetic fields surrounds adopts area vector, only has plane that described current loop surrounds to exist in the situation perpendicular to the area component of magnetic direction, and magnetic field could produce induction electromotive force to this current return effect.Therefore the necessary condition that produces induction electromotive force is the current return that will have in magnetic field, and plane that current return surrounds exists the area component perpendicular to magnetic direction, and has at least one to be variable quantity in the area of plane that surrounds of magnetic field or current return.

Shown in Figs. 9 to 11, the main apparent direction of orthogonal projection of the described measurement instrument with current sample module or rear apparent direction are exactly the direction of X-axis magnetic fields, the right apparent direction of orthogonal projection or the left apparent direction of described measurement instrument are exactly the direction of Y-axis magnetic fields, and the orthogonal projection of described measurement instrument is overlooked direction or looked up the direction that direction is exactly Z axis magnetic fields.Can explain that according to above-mentioned deduction process the measurement instrument described in confirmation with current sample module has the test of shunt running phenomenon, as shown in figure 10, when applying X-direction magnetic field, exist by current sample wire 21 ', 22 ' and current feed 11 ', the 12 ' loop that forms, and the area that this loop surrounds is vertical and X-direction, therefore on described loop, produce induction electromotive force, and then form the induction current of 24mA.As shown in figure 11, when applying Y direction magnetic field, exist by current sample wire 21 ', the loop of 22 ' and current sampling resistor device 3 ' form, and the area that surrounds of this loop is vertical and Y direction, therefore on described loop, produce induction electromotive force, and then form the induction current of 38mA.When applying Z-direction magnetic field, owing to not there is not current return, namely there is not the area of plane being surrounded by current return perpendicular to Z-direction magnetic field, i.e. Δ S=0, therefore current sample module does not produce induction electromotive force under Z-direction magnetic fields, just there is no induction current yet.

To above-mentioned test, further research is as follows:

(1) disconnect two current sample wires 21 ', 22 ' with current sampling resistor device 3 ' be electrically connected, by be positioned at two current sample wires 21 of current sampling resistor device 3 ' one end ', 22 ' short circuit, apply the X-direction alternating magnetic field of 0.5mT, the electric current that records current sample module is 24mA, thus further illustrate X-direction magnetic field only on two current sample wires 21 ', the 22 ' loop checking installation that forms with signals collecting printed circuit board (PCB) 1 ' be electrically connected has impact.

(2) separating tests 1, disconnect two current sample wires 21 ', 22 ' with signals collecting printed circuit board (PCB) 1 ' be electrically connected, with be positioned at signals collecting printed circuit board (PCB) 1 ' the two ends of circular wire be in the plane electrically connected respectively described current feed 11 ', 12 ' end, and described circular wire is positioned at and gathers printed circuit board (PCB) 1 ' outer, the area of described circular wire be greater than current feed 11 ', 12 ' end, the X-direction alternating magnetic field that applies 0.5mT, the electric current that records current sample module is 180mA;

Separating tests 2, by described circular wire be arranged on be positioned at gather printed circuit board (PCB) 1 ', and in signals collecting printed circuit board (PCB) 1 ' institute in the plane, apply the X-direction alternating magnetic field of 0.5mT, the electric current that records current sample module is 156mA;

Separating tests 3, disconnects circular wire, with current feed 11 described in a direct short circuit of straight wire ', 12 ' end, apply the X-direction alternating magnetic field of 0.5mT, the electric current that records current sample module is 12mA;

Suppose that in separating tests 1 and 2, the electric current in circular current lead is a mA, suppose in separating tests 1 and 2 current feed 11 ', electric current in 12 ' loop is b mA, there is a+b=180mA according to separating tests 1 so, there is a-b=156mA according to separating tests 2, thereby determine a=168mA, b=12mA.

Test 3 cards number verified current feed 11 ', electric current in 12 ' loop is 12mA.

Above-mentioned separating tests explanation, be positioned at signals collecting printed circuit board (PCB) 1 ' circular wire be in the plane separately positioned on signals collecting printed circuit board (PCB) 1 ' inside and outside be subject to X-direction influence of magnetic field and the induced electricity flow valuve difference that produces, namely the setting position of circular wire will affect induction current size, be arranged on signals collecting printed circuit board (PCB) 1 ' will increase induction current size outward, be arranged on signals collecting printed circuit board (PCB) 1 ' interior and will reduce induction current size.Inference thus, circular wire is arranged on to signals collecting printed circuit board (PCB) 1 ' interior formed induction current will be reduced, if reduce circular wire glass, will make induction current less, especially circular wire glass and current feed 11 ', 12 ' institute area that surrounds is when identical, should make induction current is zero.

Above-mentioned inference can be offset and explain with induction current, when circular wire is arranged on signals collecting printed circuit board (PCB) 1 ' institute in the plane and therein time, if be subject to external magnetic field to affect generation induction current, the induction current producing in circular wire and current feed 11 ', the inductive current direction that forms in 12 ' middle loop checking installation is contrary, when the area surrounding of circular wire and current feed 11 ', the 12 ' area that surrounds is when identical, in two loops, induction current size is identical, opposite direction, thus the induction current that they produce is cancelled each other.Above-mentioned inference also can use the Faraday's law of E=n × Δ B × Δ S/ Δ t to explain, when circular wire is arranged on signals collecting printed circuit board (PCB) 1 ' institute in the plane and therein time, if circular wire and current feed 11 ', have electric current in the 12 ' loop that forms, the area of plane vector that circular wire surrounds and current feed 11 ', the 12 ' area of plane vector opposite sign but equal magnitude that surrounds, the area vector sum that is them is zero, be Δ S=0, also just can not produce induction electromotive force.

The direction of described area vector can be determined by right-hand rule, with the right hand clench fist, thumb central axis by other four finger round and thumb to the right fist stretch out outward and the cylindrical coordinates that forms is basis, in the time that other four finger of the right hand is clenched fist by the direction of current in ring current loop, the sensing of thumb is exactly the direction of the area vector that surrounds of ring current loop.

According to above-mentioned test, it is zero that the present invention proposes the area of plane vector that following technical scheme makes the ring current loop in the current sample module in alternating magnetic field surround, implement the method that measurement instrument that a kind of order has current sample module is not affected by alternation external magnetic field, as shown in Figures 1 to 7, described measurement instrument comprises signals collecting printed circuit board (PCB) 1, current sampling resistor device 3, and be connected electrically in the two current sample wires 21,22 between described signals collecting printed circuit board (PCB) 1 and current sampling resistor device 3.Described signals collecting printed circuit board (PCB) 1 comprises signal processing chip 13 and two current feeds 11,12.Described current feed can be that the signals collecting being connected on the signals collecting printed circuit board (PCB) 1 of signal processing chip 13 is covered copper lead-in wire.By described two current feeds 11,12, signal processing chip 13 is electrically connected with described two current sample wires 21,22.Described method comprises the steps:

A. two current sample wires 21,22 are to spiral ring and are closely alternately twisted into a sampling cotton rope 2 with first end and the second end; As shown in Figure 1, when described two sampling wires 21,22 replace stranded while being wound in spiral ring, current direction LP21, LP22 opposite direction in every a pair of current sample conductor loop 21,22, this just means, the area vector equal and opposite in direction of the current return that every a pair of current sample conductor loop 21,22 surrounds separately, opposite direction, the area vector of the current return that every a pair of current sample conductor loop 21,22 surrounds separately and be zero; Thereby the alternating magnetic field of any direction all can not produce induction current in the spiral ring part of current sample wire 21,22.

B. by the described collection printed circuit board (PCB) 1 of two current sample wires of the first end of described sampling cotton rope 2,21,22 electrical connection, the ring current loop that current sample wire 21,22 and current feed 11,12 surround is set, the area vector sum that makes the ring current loop of two current sample wires of this first end 21,22 and two current feed 11,12 compositions surround is zero, thereby suppresses to produce induction current in the current loop of the part being electrically connected with described collection printed circuit board (PCB) 1 at two current sample wires of first end 21,22 of sampling cotton rope 2.

C. by two current sample wires 21 of the second end of described sampling cotton rope 2, the described current sampling resistor device 3 of 22 electrical connection, current sample wire 21 is set, 22 current return paths while being electrically connected with current sampling resistor device 3, make two current sample wires 21 of this second end, 22 with current sampling resistor device 3 in the area vector sum that surrounds of ring current loop that forms of current return be zero, thereby at two current sample wires 21 of the second end of sampling cotton rope 2, in the current loop of 22 parts that are electrically connected with described current sampling resistor device 3, suppress to produce induction current.

According to said method the present invention, a kind of measurement instrument with current sample module that not affected by alternation external magnetic field is also proposed, comprise signals collecting printed circuit board (PCB) 1, the current sampling resistor device 3 made from manganin material, and be connected electrically in the two current sample wires 21,22 between described signals collecting printed circuit board (PCB) 1 and current sampling resistor device 3.Described signals collecting printed circuit board (PCB) 1 comprises signal processing chip 13 and two current feeds 11,12.By described two current feeds 11,12, signal processing chip 13 is electrically connected with described two current sample wires 21,22.Especially, described two current sample wires 21,22 are spiral ring and are closely alternately twisted into a sampling cotton rope 2 with first end and the second end.The described signals collecting printed circuit board (PCB) 1 of two current sample wires of first end, 21,22 electrical connection of described sampling cotton rope 2, the area vector sum that makes the ring current loop of two current sample wires of this first end 21,22 and two current feed 11,12 compositions surround is zero.The described current sampling resistor device 3 of two current sample wires of the second end, 21,22 electrical connection of described sampling cotton rope 2, the area vector sum that the ring current loop that makes the current return of this second end two current sample wires 21,22 and current sampling resistor device 3 form surrounds is zero.Described area vector refers to the directive area of plane of the tool being surrounded by ring current loop, and the direction of described area vector is determined according to the direction of current in the ring current loop that surrounds plane.

Particularly, as shown in Figure 8, the direction of described area vector is pressed right-hand rule and is determined, with the right hand clench fist, thumb central axis P by other four finger round and thumb to the right fist stretch out outward and the cylindrical coordinates that forms is basis, other four finger of the described right hand is around forming cylinder O, when this cylindrical coordinate system is clenched fist by the direction of current LP4 in ring current loop when other four finger of the right hand, the sensing LP5 of thumb is exactly the direction of the area vector that surrounds of ring current loop.

According to above-mentioned separating tests 1 and 2, for the how specific implementation prompting that made proposition that ring current loop area vector is zero in actual mechanical process, be exactly the ring current loop by manufacturing current opposite in direction in it, and to make ring current loop surround area of plane vector be zero.

The present invention proposes to adopt following scheme in sampling cotton rope 2 is electrically connected process with signals collecting printed circuit board (PCB) 1, and described step B comprises as follows step by step,

B11. a current sample wire 22 in the first end of described sampling cotton rope 2 two current sample wires 21,22 is electrically connected to a current feed 12 of described printed circuit board (PCB) 1;

B12. after another root current sample wire 21 in the first end of described sampling cotton rope 2 two current sample wires 21,22 first being bent to semicircular in printed circuit board (PCB) 1, be electrically connected again another root current feed 11;

B13. adjust the length that described bending is Semicircular current sample wire 21, make this root bending be the annulus area equal and opposite in direction that annulus area that Semicircular current sample wire 21 surrounds and two current feeds 11,12 surround, area vector opposite direction, thus the area vector sum that makes the ring current loop of two current sample wires of described first end 21,22 and two current feed 11,12 compositions surround is zero.

The present invention realizes sampling cotton rope 2 by the first embodiment as shown in Figure 1 and is electrically connected scheme with signals collecting printed circuit board (PCB) 1, two current sample wires 21 of first end of described sampling cotton rope 2, 22 are electrically connected respectively two current feeds 11 of described printed circuit board (PCB) 1, 12, and wherein current sample wire 21 bendings are semicircular and are arranged in printed circuit board (PCB) 1, make this root bending be annulus area and two current feeds 11 that Semicircular current sample wire 21 surrounds, the 12 annulus area equal and opposite in directions that surround, area vector opposite direction, thereby make two current sample wires 21 of described first end, 22 and two current feeds 11, the area vector sum that the ring current loop of 12 compositions surrounds is zero.

As shown in Figure 1, when electric current within described bending is Semicircular current sample wire 21 flows to the direction of LP13 by LP11 to LP12, at two current feeds 11, in the 12 ring current loops that surround, will flow back to by the direction of LP14 to LP15 in another root current sample wire 22 of sampling cotton rope 2, this scheme can determine that by described right-hand rule it is the direction to drawing in drawing that bending is the area of plane vector that Semicircular current sample wire 21 surrounds, and two current feeds 11, 12 area of plane vectors that surround are from the direction in the export-oriented drawing of drawing, their opposite directions, and bending is the area of plane and two current feeds 11 that Semicircular current sample wire 21 surrounds, 12 area of plane equal and opposite in directions that surround, thereby sampling cotton rope 2 is electrically connected the area of plane that surrounds of ring circuit of formation vector with signals collecting printed circuit board (PCB) 1 is zero, thereby can not produce induction current between sampling cotton rope 2 and signals collecting printed circuit board (PCB) 1.

First embodiment of the invention as shown in Figure 1, is provided with collection signal connection end point 15,16 on described signals collecting printed circuit board (PCB) 1.Described signals collecting chip 13 comprises two current acquisition pins 131,132.Described two current feeds the 21, the 22nd, are printed on two P.e.c. current feeds on signals collecting printed circuit board (PCB) 1, and this two P.e.c. current feed is connected electrically in respectively between the two current acquisition pins 131,132 and two collection signal connection end points 15,16 of signals collecting chip 13.

In addition, described two current feeds 21,22 can also be the two current feed wires that wrapping the epidermis that insulate, and this two current feeds wire is connected electrically in respectively between the two current acquisition pins 131,132 and two collection signal connection end points 15,16 of signals collecting chip 13.

The present invention proposes to adopt following scheme in sampling cotton rope 2 is electrically connected process with current sampling resistor device 3, and described step C comprises as follows step by step, as shown in Figure 2,

C11. a current sample wire 22 in two current sample wires of the second end of described sampling cotton rope 2 21,22 is directly electrically connected to a link of described current sampling resistor device 3;

C12. another root current sample wire 21 in two current sample wires of the second end of described sampling cotton rope 2 21,22 is first attached and is wrapped in current sampling resistor device 3 surfaces, then be electrically connected another link of current sampling resistor device 3; In Fig. 2, be wrapped in the part that the dotted portion in the current sample wire 21 on current sampling resistor device 3 is blocked by current sampling resistor device 3;

C13. adjust the canoe that is wrapped in the current sample wire 21 on current sampling resistor device 3, in the direction of the longitudinal section of current sampling resistor device 3, described in order, be wrapped in that the current loop that the current sample wire 21 on current sampling resistor device 3 surrounds equates with the size that the ring current loop in current sampling resistor device 3 surrounded separately, area vector opposite direction, thereby the area vector sum that the second end two current sample wires 21,22 of described sampling cotton rope 2 and ring current loop that current sampling resistor device 3 forms are surrounded is zero.

The present invention realizes sampling cotton rope 2 by the first embodiment as shown in Figure 2 and is electrically connected scheme with current sampling resistor device 3, two current sample wires 21 of the second end of described sampling cotton rope 2, 22 are electrically connected respectively described current sampling resistor device 3, and wherein a current sample wire 21 attaches and is wrapped in current sampling resistor device 3 surfaces, in the direction of the longitudinal section of current sampling resistor device 3, described in order, being wrapped in the current loop that the current sample wire 21 on current sampling resistor device 3 surrounds equates with the size that the ring current loop in current sampling resistor device 3 surrounded separately, area vector opposite direction, make two current sample wires 21 of the second end of described sampling cotton rope 2, the area vector sum that the 22 ring current loops that form with current sampling resistor device 3 surround is zero.

As shown in Figure 2, in the time that the electric current in the current sample wire 21 being wrapped on current sampling resistor device 3 flows by the direction of LP33 to LP34, in the interior equivalent ring current loop marking with dotted line of current sampling resistor device 3 electric current by by LP30 to LP31 to another root current sample wire 22 interior outflows from sampling cotton rope 2 of the direction of LP32, this scheme can determine that by described right-hand rule the area of plane vector that the current sample wire 21 that is wrapped on current sampling resistor device 3 surrounds is the direction to drawing in drawing, and the area of plane vector surrounding in the interior equivalent ring current loop marking with dotted line of current sampling resistor device 3 is from the direction in the export-oriented drawing of drawing, their opposite directions, and be wrapped in the area of plane equal and opposite in direction that the area of plane that the current sample wire 21 on current sampling resistor device 3 surrounds and the interior equivalent ring current loop marking with dotted line of current sampling resistor device 3 surround, thereby sampling cotton rope 2 is electrically connected the area of plane that surrounds of ring circuit of formation vector with current sampling resistor device 3 is zero, thereby can not produce induction current between sampling cotton rope 2 and current sampling resistor device 3.

The present invention proposes the another program adopting in sampling cotton rope 2 is electrically connected process with signals collecting printed circuit board (PCB) 1, and described step B can also comprise as follows step by step,

B21. by described two current feeds 11,12 mutually without the ground connection that is electrically connected, be arranged on printed circuit board (PCB) 1 across;

B22. two current sample wires of the first end of described sampling cotton rope 2 21,22 are electrically connected respectively to two current feeds 11,12 of described printed circuit board (PCB) 1, thereby make between the current sample wire 21,22 that is electrically connected and current feed 11,12 and surround at least one pair of ring current loop by the point of crossing of two current feeds 11,12; Described ring current loop should be paired appearance, is conducive to make the area vector that ring current loop surrounds and is zero;

B23. adjust the position of the point of crossing of two current feeds 11,12, and the length of two current sample wires of the first end of described sampling cotton rope 2 21,22, the size in two ring current loops that surround between the current sample wire 21,22 that order is electrically connected and current feed 11,12 equates, and area vector opposite direction, thereby the area vector sum that makes the ring current loop of two current sample wires of described first end 21,22 and two current feed 11,12 compositions surround is zero.

The present invention realizes sampling cotton rope 2 by the second embodiment as shown in Figure 3 and is electrically connected scheme with signals collecting printed circuit board (PCB) 1, described two current feeds 11,12 mutually nothing be electrically connected ground connection, be arranged on printed circuit board (PCB) 1 across.Two current sample wires 21 of first end of described sampling cotton rope 2, 22 are electrically connected respectively two current feeds 11 of described printed circuit board (PCB) 1, 12, the current sample wire 21 that order is electrically connected, 22 with current feed 11, between 12 by two current feeds 11, two ring current loops that 12 point of crossing surrounds, and the annulus area equal and opposite in direction that this two ring currents loop surrounds, area vector opposite direction, thereby make two current sample wires 21 of described first end, 22 and two current feeds 11, the area vector sum that the ring current loop of 12 compositions surrounds is zero.

As shown in Figure 3, when the electric current in described current sample wire 21 press LP19 direction flow time, the direction that electric current is pressed LP18 in another root current sample wire 22 flows, at two current feeds 11, in the 12 ring current loops that surround in nearly signal processing chip 13 1 sides by point of crossing, will flow by the direction of LP17 to LP16, this scheme can be determined current sample wire 21 by described right-hand rule, 22 and two current feeds 11, 12 area of plane vectors that surround below point of crossing are directions to drawing in drawing, and two current feeds 11, 12 area of plane vectors that surround in nearly signal processing chip 13 1 sides by point of crossing are from the direction in the export-oriented drawing of drawing, their opposite directions, and current sample wire 21, 22 and two current feeds 11, 12 areas of plane that surround below point of crossing and two current feeds 11, 12 area of plane equal and opposite in directions that surround in nearly signal processing chip 13 1 sides by point of crossing, thereby sampling cotton rope 2 is electrically connected the area of plane that surrounds of ring circuit of formation vector with signals collecting printed circuit board (PCB) 1 is zero, thereby can not produce induction current between sampling cotton rope 2 and signals collecting printed circuit board (PCB) 1.

Second embodiment of the invention as shown in Figure 3, is provided with collection signal connection end point 15,16 on described signals collecting printed circuit board (PCB) 1, and a wire through-hole 14.Described two current feeds 11,12 by this wire through-hole 14 mutually without the ground connection that is electrically connected, be arranged on printed circuit board (PCB) 1 across.Described signals collecting chip 13 comprises two current acquisition pins 131,132.Described two current feeds the 11, the 12nd, are wrapping two current feed wires of the epidermis that insulate, this two current feeds wire is connected electrically in respectively between the two current acquisition pins 131,132 and two collection signal connection end points 15,16 of signals collecting chip 13, and by described wire through-hole 14 mutually without the ground connection that is electrically connected, be arranged on printed circuit board (PCB) 1 across.

Third embodiment of the invention, as shown in Figure 5, described two current feeds 11, one in 12 is the P.e.c. current feed being printed on signals collecting printed circuit board (PCB) 1, another root is the two current feed wires that wrapping the epidermis that insulate, described P.e.c. current feed is connected electrically between the current acquisition pin 131 and collection signal connection end point 16 of signals collecting chip 13, described current feed wire through described wire through-hole and P.e.c. current feed without the ground connection that is electrically connected, arranged in a crossed manner on printed circuit board (PCB), and described current feed wire is connected electrically between the current acquisition pin and collection signal connection end point of signals collecting chip.

The second embodiment and the 3rd embodiment are two current feed 11,12 situations in wire through-hole 14 interior intersections.As shown in Figure 5, a current feed 11 in two current feeds 11,12 is in the P.e.c. current feed situation being printed on signals collecting printed circuit board (PCB) 1, and described wire through-hole 14 is through described P.e.c. current feed 11.And fourth embodiment of the invention, as shown in Figure 6, described wire through-hole 14 is arranged on the side of printing path current feed 11, and the current feed wire 12 that another root is wrapping the epidermis that insulate is to intersect through the rear ability of wire through-hole 14 and P.e.c. current feed 11.The 3rd embodiment and the 4th embodiment propose two kinds and are different from the second embodiment and realize current feed 11,12 schemes in signals collecting printed circuit board (PCB) 1 interior intersection.

Fifth embodiment of the invention, as shown in Figure 7, proposes the another kind of current feed 11,12 that makes mutually without being electrically connected ground connection scheme arranged in a crossed manner.On described signals collecting printed circuit board (PCB) 1, be provided with two collection signal connection end points 15,16, and two conductive poles 151,161 that run through described signals collecting printed circuit board (PCB) 1.Described signals collecting chip 13 comprises two current acquisition pins 131,132.Described two current feeds 11,12 comprise current feed the first branch line and current feed the second branch line separately.Described two current feeds 11,12 current feed the first branch line is separately separately positioned on the two sides of signals collecting printed circuit board (PCB) 1, and be connected electrically between two conductive poles 151,161 and two current acquisition pins 131,132, make two current feed the first branch lines without the ground connection that is electrically connected, arranged in a crossed manner on printed circuit board (PCB) 1.Described two current feeds 11,12 current feed the second branch line is separately separately positioned on the two sides of signals collecting printed circuit board (PCB) 1, and be connected electrically between two conductive poles 151,161 and two collection signal connection end points 15,16, make two current feed the second branch lines without the ground connection that is electrically connected, arranged in a crossed manner on printed circuit board (PCB) 1.Thereby by two current feeds 11,12, two current acquisition pins 131,132 of described signals collecting chip 13 are electrically connected to described collection signal connection end point 15,16.Specific to fifth embodiment of the invention, as shown in Figure 7, current feed first branch line of current feed 11 is arranged on the front of signals collecting printed circuit board (PCB) 1, by depicted as solid lines, and is connected electrically between current acquisition pin 131 and conductive pole 161.Current feed first branch line of current feed 12 is arranged on the reverse side of signals collecting printed circuit board (PCB) 1, by dotted lines, and is connected electrically between current acquisition pin 132 and conductive pole 151.Current feed second branch line of current feed 11 is arranged on the reverse side of signals collecting printed circuit board (PCB) 1, by dotted lines, and is connected electrically between collection signal connection end point 15 and conductive pole 161.Current feed second branch line of current feed 12 is arranged on the front of signals collecting printed circuit board (PCB) 1, by depicted as solid lines, and is connected electrically between collection signal connection end point 16 and conductive pole 151.Described conductive pole 151 is electrically connected and is connected into a complete current feed 12 being separately positioned on the first branch line of the current feed 12 on signals collecting printed circuit board (PCB) 1 two sides and the second branch line, and current acquisition pin 132 is electrically connected to collection signal connection end point 16 by current feed 12.Described conductive pole 161 is electrically connected and is connected into a complete current feed 11 being separately positioned on the first branch line of the current feed 11 on signals collecting printed circuit board (PCB) 1 two sides and the second branch line, and current acquisition pin 131 is electrically connected to collection signal connection end point 15 by current feed 11.In fifth embodiment of the invention, described two current feeds 11,12 can be the two current feed wires that wrapping the epidermis that insulate, also can be the P.e.c. current feed being printed on signals collecting printed circuit board (PCB) 1, certainly can also be that in two current feeds 11,12 one is the two current feed wires that wrapping the epidermis that insulate, another root be the P.e.c. current feed being printed on signals collecting printed circuit board (PCB) 1.

The present invention proposes to adopt following scheme in sampling cotton rope 2 is electrically connected process with current sampling resistor device 3, and described step C can also comprise as follows step by step,

C21. two current sample wires of the second end of described sampling cotton rope 2 21,22 are electrically connected respectively to two links of described current sampling resistor device 3, two current sample wires of described the second end, 21,22 furcations are arranged on to the position away from described two links on current sampling resistor 3, and are all attached to current sampling resistor device 3 surfaces from the two sections of current sample wires 21,22 between two current sample wires of the second end, 21,22 furcations to a two current sample wire 21,22 and the connection end point of current sampling resistor device 3;

C22. adjust from two current sample wires 21 of the second end, 22 furcations to a two current sample wire 21, 22 and the connection end point of current sampling resistor device 3 between two sections of current sample wires 21, 22 length, in the direction of the longitudinal section of current sampling resistor device 3, described in order, be attached to the current sample wire 21 on current sampling resistor device 3, the ring current loop area equal and opposite in direction that current return in 22 current loops that surround and current sampling resistor device 3 surrounds, area vector opposite direction, make two current sample wires 21 of the second end of described sampling cotton rope 2, the area vector sum that the 22 ring current loops that form with current sampling resistor device 3 surround is zero.

The present invention realizes sampling cotton rope 2 by the second embodiment as shown in Figure 4 and is electrically connected scheme with current sampling resistor device 3, two current sample wires 21 of the second end of described sampling cotton rope 2, 22 are electrically connected respectively two links of described current sampling resistor device 3, two current sample wires 21 of described the second end, 22 furcations are arranged on the position away from described two links on current sampling resistor 3, and from two current sample wires 21 of the second end, 22 furcations to a two current sample wire 21, 22 and the link of current sampling resistor device 3 between two sections of current sample wires 21, 22 are all attached to current sampling resistor device 3 surfaces, in the direction of the longitudinal section of current sampling resistor device 3, described in order, be attached to the current sample wire 21 on current sampling resistor device 3, the ring current loop area equal and opposite in direction that current return in 22 current loops that surround and current sampling resistor device 3 surrounds, area vector opposite direction, make two current sample wires 21 of the second end of described sampling cotton rope 2, the area vector sum that the 22 ring current loops that form with current sampling resistor device 3 surround is zero.

As shown in Figure 4, in the time that the electric current in the current sample wire 21 being attached on current sampling resistor device 3 flows by the direction of LP38, the direction that electric current in another current sample wire 22 is just pressed LP39 flows, and then electric current will flow to the direction of LP35 by LP37 to LP36 in the interior equivalent ring current loop marking with dotted line of current sampling resistor device 3, this scheme can be determined the current sample wire 21 being attached on current sampling resistor device 3 by described right-hand rule, 22 area of plane vectors that surround are directions to drawing in drawing, and the area of plane vector surrounding in the interior equivalent ring current loop marking with dotted line of current sampling resistor device 3 is from the direction in the export-oriented drawing of drawing, their opposite directions, and be attached to the current sample wire 21 on current sampling resistor device 3, the area of plane equal and opposite in direction that the interior equivalent ring current loop marking with dotted line of 22 areas of plane that surround and current sampling resistor device 3 surrounds, thereby sampling cotton rope 2 is electrically connected the area of plane that surrounds of ring circuit of formation vector with current sampling resistor device 3 is zero, thereby can not produce induction current between sampling cotton rope 2 and current sampling resistor device 3.

" attaching " above do not refer to the fixed form of a kind of wire on current sampling resistor device 3, but guide line nestles up the state on current sampling resistor device 3.

Consider the measurement instrument that is applicable to generally use, if described measurement instrument is the measurement instrument for measuring electric power, also comprise the voltage sample wire 23 being connected electrically between described signals collecting printed circuit board (PCB) 1 and current sampling resistor device 3, described two current sample wires 21, 22, and voltage sample wire 23 is spiral ring and is closely twisted into a sampling cotton rope 2 with first end and the second end, be that voltage sample wire 23 is stranded in sampling cotton rope 2, and with two current sample wires 21, 22 are spiral ring closely twists together.Namely voltage sample wire 23 can be stranded together with current sample wire, and not affecting current sample wire spiral ring part, to realize area vector be zero scheme.

Claims

1. a measurement instrument with current sample module that not affected by alternation external magnetic field, comprise signals collecting printed circuit board (PCB) (1), the current sampling resistor device (3) made from manganin material, and be connected electrically in the two current sample wires (21,22) between described signals collecting printed circuit board (PCB) (1) and current sampling resistor device (3); Described signals collecting printed circuit board (PCB) (1) comprises signal processing chip (13) and two current feeds (11,12); By described two current feeds (11,12), signal processing chip (13) is electrically connected with described two current sample wires (21,22); It is characterized in that:

Described two current sample wires (21,22) are spiral ring and are closely alternately twisted into a sampling cotton rope (2) with first end and the second end;

Two current sample wires of first end (21,22) of described sampling cotton rope (2) are electrically connected described signals collecting printed circuit board (PCB) (1), and making two current sample wires of this first end (21,22) and the area vector sum that the ring current loop of two current feeds (11,12) composition surrounds is zero;

Two current sample wires of the second end (21,22) of described sampling cotton rope (2) are electrically connected described current sampling resistor device (3), and the area vector sum that the ring current loop that makes two current sample wires of this second end (21,22) and the current return of current sampling resistor device (3) form surrounds is zero;

Described area vector refers to the directive area of plane of the tool being surrounded by ring current loop, and the direction of described area vector is determined according to the direction of current in the ring current loop that surrounds plane.

2. the measurement instrument with current sample module that not affected by alternation external magnetic field according to claim 1, is characterized in that:

Two current sample wires (21 of first end of described sampling cotton rope (2), 22) be electrically connected respectively two current feeds (11 of described printed circuit board (PCB) (1), 12), and wherein a current sample wire (21) bending is semicircular and is arranged in printed circuit board (PCB) (1), make this root bending be annulus area and two current feeds (11 that Semicircular current sample wire (21) surrounds, 12) the annulus area equal and opposite in direction surrounding, area vector opposite direction, thereby make two current sample wires (21 of described first end, 22) with two current feeds (11, 12) the area vector sum that the ring current loop of composition surrounds is zero.

3. the measurement instrument with current sample module that not affected by alternation external magnetic field according to claim 1, is characterized in that:

Described two current feeds (11,12) are mutually without the ground connection that is electrically connected, be arranged on printed circuit board (PCB) (1) across;

Two current sample wires (21 of first end of described sampling cotton rope (2), 22) be electrically connected respectively two current feeds (11 of described printed circuit board (PCB) (1), 12), the current sample wire (21 that order is electrically connected, 22) with current feed (11, 12) between by two current feeds (11, 12) point of crossing surrounds at least one pair of ring current loop, and the annulus area equal and opposite in direction that described ring current loop surrounds, area vector opposite direction, thereby make two current sample wires (21 of described first end, 22) with two current feeds (11, 12) the area vector sum that the ring current loop of composition surrounds is zero.

4. the measurement instrument with current sample module that not affected by alternation external magnetic field according to claim 1, is characterized in that:

Two current sample wires (21 of the second end of described sampling cotton rope (2), 22) be electrically connected respectively described current sampling resistor device (3), and wherein a current sample wire (21) attaches and is wrapped in current sampling resistor device (3) surface, in the longitudinal section direction of current sampling resistor device (3), described in order, being wrapped in the current loop that the current sample wire (21) on current sampling resistor device (3) surrounds equates with the size that the ring current loop in current sampling resistor device (3) surrounded separately, area vector opposite direction, make two current sample wires (21 of the second end of described sampling cotton rope (2), 22) the area vector sum that surrounds of ring current loop forming with current sampling resistor device (3) is zero.

5. the measurement instrument with current sample module of avoiding because of external magnetic field shunt running according to claim 1, is characterized in that:

Two current sample wires (21 of the second end of described sampling cotton rope (2), 22) be electrically connected respectively two links of described current sampling resistor device (3), two current sample wires (21 of described the second end, 22) furcation is arranged on the upper position away from described two links of current sampling resistor (3), and from two current sample wires (21 of the second end, 22) furcation to a two current sample wire (21, 22) two sections of current sample wires (21 and between the link of current sampling resistor device (3), 22) be all attached to current sampling resistor device (3) surface, in the longitudinal section direction of current sampling resistor device (3), described in order, be attached to the current sample wire (21 on current sampling resistor device (3), 22) the ring current loop area equal and opposite in direction that the current return in the current loop surrounding and current sampling resistor device (3) surrounds, area vector opposite direction, make two current sample wires (21 of the second end of described sampling cotton rope (2), 22) the area vector sum that surrounds of ring current loop forming with current sampling resistor device (3) is zero.

6. the method that the measurement instrument that an order has current sample module is not affected by alternation external magnetic field, described measurement instrument comprises signals collecting printed circuit board (PCB) (1), current sampling resistor device (3), and be connected electrically in the two current sample wires (21,22) between described signals collecting printed circuit board (PCB) (1) and current sampling resistor device (3); Described signals collecting printed circuit board (PCB) (1) comprises signal processing chip (13) and two current feeds (11,12); By described two current feeds (11,12), signal processing chip (13) is electrically connected with described two current sample wires (21,22); It is characterized in that described method comprises the steps:

A. two current sample wires (21,22) are to spiral ring and are closely alternately twisted into a sampling cotton rope (2) with first end and the second end;

B. two current sample wires of the first end of described sampling cotton rope (2) (21,22) are electrically connected to described collection printed circuit board (PCB) (1), the ring current loop that current sample wire (21,22) and current feed (11,12) surround is set, and making two current sample wires of this first end (21,22) and the area vector sum that the ring current loop of two current feeds (11,12) composition surrounds is zero;

C. two current sample wires of the second end of described sampling cotton rope (2) (21,22) are electrically connected to described current sampling resistor device (3), current return path when current sample wire (21,22) is set is electrically connected with current sampling resistor device (3), the area vector sum that the ring current loop that makes two current sample wires of this second end (21,22) and the current return in current sampling resistor device (3) form surrounds is zero.

7. order according to claim 11 has the method that the measurement instrument of current sample module is not affected by alternation external magnetic field, it is characterized in that:

Described step B comprises as follows step by step,

B11. the current sample wire (22) in the first end of described sampling cotton rope (2) two current sample wires (21,22) is electrically connected to a current feed (12) of described printed circuit board (PCB) (1);

B12. after another root current sample wire (21) in the first end of described sampling cotton rope (2) two current sample wires (21,22) first being bent to semicircular in printed circuit board (PCB) (1), be electrically connected again another root current feed (11);

B13. adjust the length that described bending is Semicircular current sample wire (21), make this root bending be the annulus area equal and opposite in direction that annulus area that Semicircular current sample wire (21) surrounds and two current feeds (11,12) surround, area vector opposite direction is zero thereby make two current sample wires of described first end (21,22) and the area vector sum that the ring current loop of two current feeds (11,12) composition surrounds.

8. order according to claim 11 has the method that the measurement instrument of current sample module is not affected by alternation external magnetic field, it is characterized in that:

Described step B comprises as follows step by step,

B21. by described two current feeds (11,12) mutually without the ground connection that is electrically connected, be arranged on printed circuit board (PCB) (1) across;

B22. two current sample wires of the first end of described sampling cotton rope (2) (21,22) are electrically connected respectively to two current feeds (11,12) of described printed circuit board (PCB) (1), thereby make between the current sample wire (21,22) that is electrically connected and current feed (11,12) and surround at least one pair of ring current loop by the point of crossing of two current feeds (11,12);

B23. adjust the position of the point of crossing of two current feeds (11,12), and the length of two current sample wires of the first end of described sampling cotton rope (2) (21,22), the size in two ring current loops that surround between the current sample wire (21,22) that order is electrically connected and current feed (11,12) equates, and area vector opposite direction is zero thereby make two current sample wires of described first end (21,22) and the area vector sum that the ring current loop of two current feeds (11,12) composition surrounds.

9. order according to claim 11 has the method that the measurement instrument of current sample module is not affected by alternation external magnetic field, it is characterized in that:

Described step C comprises as follows step by step,

C11. the current sample wire (22) in two current sample wires of the second end of described sampling cotton rope (2) (21,22) is directly electrically connected to a link of described current sampling resistor device (3);

C12. another root current sample wire (21) in two current sample wires of the second end of described sampling cotton rope (2) (21,22) is first attached and is wrapped in current sampling resistor device (3) surface, then be electrically connected another link of current sampling resistor device (3);

C13. adjust the canoe that is wrapped in the current sample wire (21) on current sampling resistor device (3), in the longitudinal section direction of current sampling resistor device (3), described in order, being wrapped in the current loop that the current sample wire (21) on current sampling resistor device (3) surrounds equates with the size that the ring current loop in current sampling resistor device (3) surrounded separately, area vector opposite direction, thereby make two current sample wires (21 of the second end of described sampling cotton rope (2), 22) the area vector sum that surrounds of ring current loop forming with current sampling resistor device (3) is zero.

10. the measurement instrument that order according to claim 11 has a current sample module is not affected and the method for shunt running by alternation external magnetic field, it is characterized in that:

Described step C comprises as follows step by step,

C21. by two current sample wires (21 of the second end of described sampling cotton rope (2), 22) be electrically connected respectively two links of described current sampling resistor device (3), by two current sample wires (21 of described the second end, 22) furcation is arranged on the upper position away from described two links of current sampling resistor (3), and from two current sample wires (21 of the second end, 22) furcation to a two current sample wire (21, 22) two sections of current sample wires (21 and between the connection end point of current sampling resistor device (3), 22) be all attached to current sampling resistor device (3) surface,

C22. adjust from two current sample wires (21 of the second end, 22) furcation to a two current sample wire (21, 22) two sections of current sample wires (21 and between the connection end point of current sampling resistor device (3), 22) length, in the longitudinal section direction of current sampling resistor device (3), described in order, be attached to the current sample wire (21 on current sampling resistor device (3), 22) the ring current loop area equal and opposite in direction that the current return in the current loop surrounding and current sampling resistor device (3) surrounds, area vector opposite direction, make two current sample wires (21 of the second end of described sampling cotton rope (2), 22) the area vector sum that surrounds of ring current loop forming with current sampling resistor device (3) is zero.