CN203204032U - Current sampling module-contained measurement instrument free of alternating external magnetic field influence - Google Patents

Abstract

The utility model relates to a current sampling module-contained measurement instrument free of an alternating external magnetic field influence. The provided measurement instrument comprises a signal collection copper-coated lead connected to a printed circuit board of an integrated circuit, a current sampling resistor made from a manganese-copper alloy material, and current sampling leads, wherein the two current sampling leads are twisted into a sampling rope by a tightly alternate way. A vector sum of areas encircled by annular current loops formed by a first end portion of the sampling rope and two current leads is zero; and a vector sum of areas encircled by annular current loops formed by a second end portion of the sampling rope and a current sampling resistor is zero. According to the utility model, because of improvement of a wiring mode and a wiring structure, a current loop area that can be influenced by an external alternating magnetic field can be reduced or even eliminated and thus an induction voltage vector sum at the alternating magnetic field is zero, thereby substantially reducing or even eliminating the influence on a current sampling module by the external alternating magnetic field.

Description

The measurement instrument with current sample module that not influenced by the alternation external magnetic field

Technical field

The utility model relates to the measurement instrument that prevents that measurement instrument from occurring misreading the method for several situations and using this method, particularly relate to and prevent that the measurement instrument with current sample module from producing induction current because influenced by outside alternating magnetic field, cause the improper electric current of measurement instrument to show or the method for counting and use the measurement instrument of this method.

Background technology

Typical case's representative with measurement instrument of current sample module is electric energy meter, or power meter, the measurement instrument that also comprises some special measurement purposes, for example only need to measure the reometer of current data, current data and other data need be combined measurement instrument of finishing measurement etc., these measurement instruments are owing to all carry out sampled measurements to current signal, thereby all be provided be used to the separate modular of finishing current sample, the comprehensively sampling module that perhaps has the current sample functional module, the utility model are referred to as this type of measurement instrument the measurement instrument with current sample module.Measurement instrument will be subjected to the actual motion environmental impact and the situation of accuracy of measurement occurs influencing when reality is used.For the measurement instrument with current sample module, if operate in the environment with outside alternating magnetic field, the external magnetic field of alternation will make in the current sample module in the measurement instrument and produce induction current.Described outside alternating magnetic field may come near the power equipment of measurement instrument, line of electric force etc.When normal the measurement, the induction current that influenced by outside alternating magnetic field and produce influences actual measured results and is difficult for realizing, but when measurement instrument is not having under the situation of sampled measurements, the induction current that is subjected to outside alternating magnetic field to influence generation also will be gathered by the current sample module, and induction current counted actual measured results, cause measurement instrument when energising, but do not have under the current conditions of measurement, the measurement instrument of electronic type and measurement current module are influenced by outside alternating magnetic field, and the improper electric current that causes shows or counting, and this kind situation is called as the shunt running phenomenon for power measuring instrument.

Can embody the improper electric weight counting that described outside alternating magnetic field causes quantitatively by test, 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 expense control intelligent electric energy meter that described conduct is had the measurement instrument 9 of current sample module applies directions X respectively, the 0.5mT of Y-direction and Z direction, namely 0.5 the milli tesla alternating magnetic field, record and be subjected to directions X 0.5mT alternating magnetic field to influence the induction current that in the current sample module, produces 24mA, be subjected to Y-direction 0.5mT alternating magnetic field to influence the induction current that in the current sample module, produces 38mA, be subjected to Z direction 0.5mT alternating magnetic field to influence the induction current that in the current sample module, produces 0mA.By above-mentioned test as seen, influenced by outside alternating magnetic field, described measurement instrument is when energising, but do not have under the current conditions of measurement, the measurement instrument of electronic type and measurement current module are influenced by outside alternating magnetic field, and the improper electric current that causes shows or the counting phenomenon, or the shunt running phenomenon exists really.

Be commonly used in family and industrial user with the single-phase expense control intelligent electric energy meter that uses in the described test electricity tariff meter as representative, well imagine that described shunt running phenomenon cause unnecessary economic loss obviously will for the electricity tariff meter user.The measurement instrument metering that the shunt running that produces so influenced by outside alternating magnetic field not only can make all have the current sample module is inaccurate, and the defective that its performance is given prominence to the most, had the greatest impact is exactly bring unnecessary economic loss can for the user of family expenses or industrial Changeable electric meter.

The utility model content

The technical problems to be solved in the utility model is to avoid the deficiencies in the prior art part and proposes a kind of measurement instrument that prevents from having the current sample module and be subjected 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 using this method.The utility model is according to the faradic principle of inducting, by improving the mode of connection and wiring construction, significantly reduce even offset fully the ring current area that the loop surrounds of the hard to bear action of alternating magnetic field of energy in the current sample module, thereby suppress outside alternating magnetic field to the influence of current sample module.

The utility model solve the technical problem can be by realizing by the following technical solutions:

Design, a kind of measurement instrument with current sample module that not influenced by the alternation external magnetic field of manufacturing, comprise the signals collecting printed circuit board (PCB), the current sampling resistor device made from the manganin material, and be connected electrically in two current sample leads between described signals collecting printed circuit board (PCB) and the 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 leads.Especially, described two current sample leads in the shape of a spiral ring-type closely alternately be twisted into a sampling cotton rope with first end and the second end.Two current sample leads of the first end of described sampling cotton rope are electrically connected described signals collecting printed circuit board (PCB), and the area vector sum that the ring current loop that makes two current sample leads of this first end and two current feeds form surrounds is zero.Two current sample leads 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 leads of this second end and current sampling resistor device constitute surrounds is zero.Described area vector refers to the area of plane with direction that surrounded by the 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 the plane.

Particularly, the direction of described area vector is pressed the right-handed helix rule and is determined, namely with the right hand clench fist, the thumb central axis by other four refer to round and thumb stretch out outside the fist to the right and the cylindrical coordinates that constitutes is the basis, when the right hand other four when referring to clench fist by ring current current in loop direction, 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 the signals collecting printed circuit board (PCB), two current sample leads of the first end of described sampling cotton rope are electrically connected two current feeds of described printed circuit board (PCB) respectively, and wherein the bending of a current sample lead is arranged in the printed circuit board (PCB) with being semicircular, make this root bending be the annulus area equal and opposite in direction that annulus area that Semicircular current sample lead surrounds and two current feeds surround, the area vector direction is opposite, thereby the area vector sum that the ring current loop that makes two current sample leads of described first end and two current feeds form surrounds is zero.

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

The scheme that another kind of sampling cotton rope is electrically connected with the signals collecting printed circuit board (PCB), described two current feeds do not have the ground connection that is electrically connected mutually, are arranged on the printed circuit board (PCB) across.Two current sample leads of the first end of described sampling cotton rope are electrically connected two current feeds of described printed circuit board (PCB) respectively, point of crossing by two current feeds between the current sample lead that order is electrically connected and the current feed surrounds at least one pair of ring current loop, and the annulus area equal and opposite in direction that described ring current loop surrounds, the area vector direction is opposite, thereby the area vector sum that the ring current loop that makes two current sample leads of described first end and two current feeds form surrounds is zero.

Particularly, described signals collecting printed circuit board (PCB) is provided with two and gathers the signal connection end point, and a wire through-hole.Described two current feeds do not have the ground connection that is electrically connected mutually, are arranged on the printed circuit board (PCB) across by this wire through-hole.Described signals collecting chip comprises two current acquisition pins.Described two current feeds are the two current feed leads that wrapping the epidermis that insulate, this two current feeds lead is connected electrically in the two current acquisition pins and two of signals collecting chip respectively and gathers between the signal connection end point, and does not have the ground connection that is electrically connected mutually, is arranged on the printed circuit board (PCB) across by described wire through-hole.Perhaps, one in described two current feeds is the P.e.c. current feed that is printed on the signals collecting printed circuit board (PCB), another root is the two current feed leads that wrapping the epidermis that insulate, described P.e.c. current feed is connected electrically in the current acquisition pin of signals collecting chip and gathers between the signal connection end point, described current feed lead passes described wire through-hole and the P.e.c. current feed does not have the ground connection of being electrically connected, arranged in a crossed manner on printed circuit board (PCB), and described current feed lead is connected electrically between the current acquisition pin and collection signal connection end point of signals collecting chip.

Another makes current feed be electrically connected scheme arranged in a crossed manner mutually, and described signals collecting printed circuit board (PCB) is provided with two and gathers the signal connection end point, 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 first branch line and current feed second branch line separately.Described two current feeds current feed first branch line separately is separately positioned on the two sides of signals collecting printed circuit board (PCB), and be connected electrically between two conductive poles and the two current acquisition pins, make two current feeds, first branch line not have the ground connection of being electrically connected, arranged in a crossed manner on printed circuit board (PCB).Described two current feeds current feed second branch line separately is separately positioned on the two sides of signals collecting printed circuit board (PCB), and be connected electrically in two conductive poles and two and gather between the signal connection end point, make two current feeds, second branch line not have the ground connection of being 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 leads that wrapping the epidermis that insulate, and perhaps, described two current feeds are the P.e.c. current feeds that are printed on the signals collecting printed circuit board (PCB).

The scheme that a kind of cotton rope of sampling is electrically connected with the current sampling resistor device, two current sample leads of the second end of described sampling cotton rope are electrically connected described current sampling resistor device respectively, and wherein a current sample lead attaches and is wrapped in current sampling resistor device surface, on the direction of the longitudinal section of current sampling resistor device, the area equal and opposite in direction that makes current loop that the described current sample lead that is wrapped on the current sampling resistor device surrounds and the ring current loop in the current sampling resistor device surround separately, the area vector direction is opposite, and the area vector sum that the ring current loop that two current sample leads of the second end of described sampling cotton rope and current sampling resistor device are constituted surrounds is zero.

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

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

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

The utility model 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 the current sample module is not influenced by the alternation external magnetic field, described measurement instrument comprises the signals collecting printed circuit board (PCB), the current sampling resistor device, and be connected electrically in two current sample leads between described signals collecting printed circuit board (PCB) and the 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 leads.Described method comprises the steps:

A. with two current sample leads in the shape of a spiral ring-type closely alternately be twisted into a sampling cotton rope with first end and the second end;

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

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

Particularly, described step B comprises step by step following,

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

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

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

In addition, described step B can also comprise step by step following,

B21. described two current feeds are not had the ground connection that is electrically connected mutually, are arranged on the printed circuit board (PCB) across;

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

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

Particularly, described step C comprises step by step following,

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

C12. another root current sample lead in two current sample leads of the second end of described sampling cotton rope is attached earlier and be wrapped in current sampling resistor device surface, be electrically connected another link of current sampling resistor device again;

B13. adjust the canoe that is wrapped in the current sample lead on the current sampling resistor device, on the direction of the longitudinal section of current sampling resistor device, the area equal and opposite in direction, the area vector direction that make current loop that the described current sample lead that is wrapped on the current sampling resistor device surrounds and ring current loop in the current sampling resistor device surround separately are opposite, thereby the area vector sum that the ring current loop that the two current sample leads of the second end that make described sampling cotton rope and current sampling resistor device constitute surrounds is zero.

In addition, described step C can also comprise step by step following,

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

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

Compare with prior art, the technique effect of the utility model " measurement instrument and its implementation of not influenced by the alternation external magnetic field " is:

The utility model is according to the faradic principle of inducting, by improving the mode of connection and wiring construction, utilization is the directivity in the face territory, space on border with the current loop, reduce even offset the current return area of the hard to bear outside action of alternating magnetic field of energy, make it at the induced voltage vector of alternating magnetic field and be zero, thereby significantly reduce even offset outside alternating magnetic field fully to the influence of current sample module, eliminating described measurement instrument substantially influences influence to the current sample module because being subjected to outside alternating magnetic field.

Description of drawings

Fig. 1 is the main synoptic diagram of looking of orthogonal projection of the utility model " measurement instrument and its implementation of not influenced by the alternation external magnetic field " first embodiment;

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

Fig. 3 is the main synoptic diagram of looking of the orthogonal projection of the utility model second embodiment;

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

Fig. 5 is the main synoptic diagram of looking of orthogonal projection of the signals collecting printed circuit board (PCB) 1 of the utility model the 3rd embodiment;

Fig. 6 is the main synoptic diagram of looking of orthogonal projection of the signals collecting printed circuit board (PCB) 1 of the utility model the 4th embodiment;

Fig. 7 is the main synoptic diagram of looking of orthogonal projection of the signals collecting printed circuit board (PCB) 1 of the utility model the 5th embodiment;

Fig. 8 be the utility model area vector based on the synoptic diagram of cylindrical coordinate system;

Fig. 9 is that the external magnetic field is to the Distribution of Magnetic Field synoptic diagram of measurement instrument influence test;

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

Figure 11 is that synoptic 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 the accompanying drawing.

The utility model scheme is that the basis is further eliminated shunt running test and put into practice with the described test of preamble, therefore describes technical solutions of the utility model 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 comprise at least signals collecting printed circuit board (PCB) 1 ', current sampling resistor device 3 ', and be used for to be electrically connected described signals collecting printed circuit board (PCB) 1 ' with current sampling resistor device 3 ' two current sample leads 21 ', 22 '.Signals collecting printed circuit board (PCB) 1 ', current sampling resistor device 3 ' and current sample lead 21 ', 22 ' constitute the current sample module of measurement instrument.Described signals collecting printed circuit board (PCB) 1 ' on should be provided with at least signal processing chip 13 ', and be used for finishing signal processing chip 13 ' with current sample lead 21 ', the 22 ' current feed 11 that is electrically connected ', 12 '.Confirm the test that described measurement instrument with current sample module has the shunt running phenomenon according to preamble, as shown in Figure 8, when the outside alternating magnetic field of the 0.5mT that applies X-direction, the electric current that records in the current sample module is 24mA; When the outside alternating magnetic field of the 0.5mT that applies Y direction, the electric current that records in the current sample module is 38mA; When the outside alternating magnetic field of the 0.5mT that applies Z-direction, the electric current that records in the current sample module is 0mA.Produce induction current and just certainly lead to induction electromotive force in the current sample module, according to faraday's law of magnetic induction, the size of induction electromotive force E is directly proportional with the flux change rate ΔΦ in magnetic field, namely

E＝n×ΔΦ/Δt，

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

ΔΦ＝ΔB×ΔS。

Can get according to above-mentioned two equatioies,

E＝n×ΔB×ΔS/Δt。

In spatial domain, the area that the current loop of magnetic field effect surrounds adopts area vector, and the plane of having only described current loop to surround exists under 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 there is the area component perpendicular to magnetic direction in the plane that current return surrounds, 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, described orthogonal projection master apparent direction or back apparent direction with measurement instrument of current sample module is exactly the direction of X-axis magnetic field effect, the right apparent direction of the orthogonal projection of described measurement instrument or left apparent direction are exactly the direction of Y-axis magnetic field effect, and the orthogonal projection of described measurement instrument is overlooked direction or looked up the direction that direction is exactly the effect of Z axle magnetic field.Can explain the test that confirms that described measurement instrument with current sample module has the shunt running phenomenon according to above-mentioned deduction process, as shown in figure 10, when applying X-direction magnetic field, existence by current sample lead 21 ', 22 ' and current feed 11 ', the 12 ' loop that constitutes, and the area that this loop surrounds is vertical and X-direction, therefore produce induction electromotive force in described loop, and then form the induction current of 24mA.As shown in figure 11, when applying Y direction magnetic field, exist by current sample lead 21 ', the loop of 22 ' and current sampling resistor device 3 ' constitute, and the vertical and Y direction of area that surrounds of this loop, therefore produce induction electromotive force in described loop, and then form the induction current of 38mA.When applying Z-direction magnetic field, owing to there is not current return, just there is not the area of plane that is surrounded by current return perpendicular to Z-direction magnetic field, i.e. Δ S=0, therefore the current sample module does not produce induction electromotive force under the effect of Z-direction magnetic field, does not just have induction current yet.

Further research is as follows to above-mentioned test:

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

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

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

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

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

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

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

Above-mentioned inference can be offset with induction current and explain, when circular lead is arranged on the plane, signals collecting printed circuit board (PCB) 1 ' place and within it the time, if be subjected to external magnetic field to influence the generation induction current, the induction current that in circular lead, produces and current feed 11 ', the inductive current direction that forms in the 12 ' middle loop checking installation is opposite, when the area that surrounds of circular lead and current feed 11 ', when the 12 ' area that surrounds is identical, the induction current size is identical in two loops, direction is opposite, thereby 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 lead is arranged on the plane, signals collecting printed circuit board (PCB) 1 ' place and within it the time, if circular lead and current feed 11 ', electric current is arranged in the 12 ' loop that constitutes, the area of plane vector that circular lead 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 the right-handed helix rule, namely with the right hand clench fist, the thumb central axis by other four refer to round and thumb stretch out outside the fist to the right and the cylindrical coordinates that constitutes is the basis, when the right hand other four when referring to clench fist by ring current current in loop direction, the sensing of thumb is exactly the direction of the area vector that surrounds of ring current loop.

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

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

B. the two current sample leads 21 of first end, 22 with described sampling cotton rope 2 are electrically connected described collection printed circuit board (PCB) 1, current sample lead 21,22 and the ring current loop that surrounds of current feed 11,12 is set, the area vector sum that makes two current sample leads 21 of this first end, 22 and two current feeds 11, the 12 ring current loops of forming surround is zero, thereby suppresses to produce induction current in the current loop of the two current sample leads 21 of first end of cotton rope 2 of sampling, 22 parts that are electrically connected with described collection printed circuit board (PCB) 1.

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

According to said method the utility model a kind of measurement instrument with current sample module that not influenced by the alternation external magnetic field is proposed also, comprise signals collecting printed circuit board (PCB) 1, the current sampling resistor device made from the manganin material 3, and be connected electrically in two current sample leads 21,22 between described signals collecting printed circuit board (PCB) 1 and the 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 leads 21,22.Especially, described two current sample leads 21,22 in the shape of a spiral ring-type closely alternately be twisted into a sampling cotton rope 2 with first end and the second end.Two current sample leads 21 of the first end of described sampling cotton rope 2,22 are electrically connected described signals collecting printed circuit board (PCB) 1, and the area vector sum that makes two current sample leads 21 of this first end, 22 and two current feeds 11, the 12 ring current loops of forming surround is zero.Two current sample leads 21 of the second end of described sampling cotton rope 2,22 are electrically connected described current sampling resistor device 3, and the area vector sum that the ring current loop that makes two current sample leads 21 of this second end, 22 constitute with the current return of current sampling resistor device 3 surrounds is zero.Described area vector refers to the area of plane with direction that surrounded by the 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 the plane.

Particularly, as shown in Figure 8, the direction of described area vector is pressed the right-handed helix rule and is determined, namely with the right hand clench fist, thumb central axis P by other four refer to round and thumb stretch out outside the fist to the right and the cylindrical coordinates that constitutes is the basis, other four finger of the described right hand is around forming cylinder O, this cylindrical coordinate system when the right hand other four when referring to clench fist by ring current current in loop direction LP4, 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 in actual mechanical process how specific implementation make ring current loop area vector and the prompting that has been zero proposition, be exactly by making the ring current loop of current opposite in direction in it, and make the ring current loop surround area of plane vector and be zero.

The utility model proposes at sampling cotton rope 2 and be electrically connected in the process the following scheme of employing with signals collecting printed circuit board (PCB) 1, namely described step B comprise step by step following,

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

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

B13. adjust the length that described bending is Semicircular current sample lead 21, make this root bending be the annulus area equal and opposite in direction that annulus area that Semicircular current sample lead 21 surrounds and two current feeds 11,12 surround, the area vector direction is opposite, thereby the area vector sum that makes two current sample leads 21 of described first end, 22 and two current feeds 11, the 12 ring current loops of forming surround is zero.

First embodiment of the utility model by the as shown in Figure 1 cotton rope 2 of realizing sampling is electrically connected scheme with signals collecting printed circuit board (PCB) 1, two current sample leads 21 of the first end of described sampling cotton rope 2,22 are electrically connected two current feeds 11 of described printed circuit board (PCB) 1 respectively, 12, and wherein current sample lead 21 bendings are arranged in the printed circuit board (PCB) 1 with being semicircular, make this root bending be annulus area and two current feeds 11 that Semicircular current sample lead 21 surrounds, the 12 annulus area equal and opposite in directions that surround, the area vector direction is opposite, thereby makes two current sample leads 21 of described first end, 22 and two current feeds 11, the area vector sum that the 12 ring current loops of forming surround is zero.

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

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

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

The utility model proposes at sampling cotton rope 2 and be electrically connected in the process the following scheme of employing with current sampling resistor device 3, namely described step C comprise step by step following, as shown in Figure 2,

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

C12. another root current sample lead 21 in two current sample leads 21 of the second end, 22 of described sampling cotton rope 2 is attached earlier and be wrapped in current sampling resistor device 3 surfaces, be electrically connected another link of current sampling resistor device 3 again; Be wrapped in the part that the dotted portion in the current sample lead 21 on the current sampling resistor device 3 is blocked by current sampling resistor device 3 among Fig. 2;

C13. adjust the canoe that is wrapped in the current sample lead 21 on the current sampling resistor device 3, on the direction of the longitudinal section of current sampling resistor device 3, the area equal and opposite in direction, the area vector direction that make current loop that the described current sample lead 21 that is wrapped on the current sampling resistor device 3 surrounds and ring current loop in the current sampling resistor device 3 surround separately are opposite, thereby the area vector sum that the ring current loop that two current sample leads 21 of the second end, 22 of described sampling cotton rope 2 are constituted with current sampling resistor device 3 surrounds is zero.

First embodiment of the utility model by the as shown in Figure 2 cotton rope 2 of realizing sampling is electrically connected scheme with current sampling resistor device 3, two current sample leads 21 of the second end of described sampling cotton rope 2,22 are electrically connected described current sampling resistor device 3 respectively, and wherein a current sample lead 21 attaches and is wrapped in current sampling resistor device 3 surfaces, on the direction of the longitudinal section of current sampling resistor device 3, the area equal and opposite in direction that makes current loop that the described current sample lead 21 that is wrapped on the current sampling resistor device 3 surrounds and the ring current loop in the current sampling resistor device 3 surround separately, the area vector direction is opposite, makes two current sample leads 21 of the second end of described sampling cotton rope 2, the area vector sum that the 22 ring current loops that constitute with current sampling resistor device 3 surround is zero.

As shown in Figure 2, when the electric current in the current sample lead 21 on being wrapped in current sampling resistor device 3 is mobile by the direction of LP33 to LP34, in the equivalent ring current loop that with dashed lines marks in current sampling resistor device 3 electric current will by LP30 to LP31 to the direction of LP32 from another root current sample lead 22 of sampling cotton rope 2 in outflow, it is the direction outside drawing in the drawing that this scheme can determine to be wrapped in area of plane vector that the current sample lead 21 on the current sampling resistor device 3 surrounds by described right-handed helix rule, and the area of plane vector that the equivalent ring current loop that with dashed lines marks in current sampling resistor device 3 surrounds is the direction in the export-oriented drawing of drawing, their directions are opposite, and be wrapped in the area of plane equal and opposite in direction that with dashed lines mark in the area of plane that the current sample lead 21 on the current sampling resistor device 3 surrounds and the current sampling resistor device 3 equivalent ring current loop surrounds, thereby sampling cotton rope 2 is electrically connected the vector of the area of plane that the ring circuit that forms surrounds with current sampling resistor device 3 and be zero, thereby can not produce induction current between cotton rope 2 and the current sampling resistor device 3 sampling.

The utility model proposes the sampling cotton rope 2 be electrically connected the another program that adopts in the process with signals collecting printed circuit board (PCB) 1, namely described step B can also comprise step by step following,

B21. described two current feeds 11,12 are not had the ground connection that is electrically connected mutually, are arranged on the printed circuit board (PCB) 1 across;

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

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

Second embodiment of the utility model by the as shown in Figure 3 cotton rope 2 of realizing sampling is electrically connected scheme with signals collecting printed circuit board (PCB) 1, and described two current feeds 11,12 do not have the ground connection that is electrically connected mutually, are arranged on the printed circuit board (PCB) 1 across.Two current sample leads 21 of the first end of described sampling cotton rope 2,22 are electrically connected two current feeds 11 of described printed circuit board (PCB) 1 respectively, 12, the current sample lead 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, the area vector direction is opposite, thereby makes two current sample leads 21 of described first end, 22 and two current feeds 11, the area vector sum that the 12 ring current loops of forming surround is zero.

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

The utility model second embodiment, as shown in Figure 3, described signals collecting printed circuit board (PCB) 1 is provided with gathers signal connection end point 15,16, and a wire through-hole 14.Described two current feeds 11,12 do not have the ground connection that is electrically connected mutually, are arranged on the printed circuit board (PCB) 1 across by this wire through-hole 14.Described signals collecting chip 13 comprises two current acquisition pins 131,132.Described two current feeds 11, the 12nd are wrapping two current feed leads of the epidermis that insulate, this two current feeds lead is connected electrically in the two current acquisition pins 131,132 and two of signals collecting chip 13 respectively and gathers between the signal connection end point 15,16, and does not have the ground connection that is electrically connected mutually, is arranged on the printed circuit board (PCB) 1 across by described wire through-hole 14.

The utility model the 3rd embodiment, as shown in Figure 5, described two current feeds 11, one in 12 is the P.e.c. current feed that is printed on the signals collecting printed circuit board (PCB) 1, another root is the two current feed leads that wrapping the epidermis that insulate, described P.e.c. current feed is connected electrically in the current acquisition pin 131 of signals collecting chip 13 and gathers between the signal connection end point 16, described current feed lead passes described wire through-hole and the P.e.c. current feed does not have the ground connection of being electrically connected, arranged in a crossed manner on printed circuit board (PCB), and described current feed lead is connected electrically between the current acquisition pin and collection signal connection end point of signals collecting chip.

Second embodiment and the 3rd embodiment are the situations that two current feeds 11,12 intersect in wire through-hole 14.As shown in Figure 5, a current feed 11 in two current feeds 11,12 is that described wire through-hole 14 passes described P.e.c. current feed 11 under the P.e.c. current feed situation that is printed on the signals collecting printed circuit board (PCB) 1.And the utility model the 4th embodiment, as shown in Figure 6, described wire through-hole 14 is arranged on the next door of printing path current feed 11, and the current feed lead 12 that another root is wrapping the epidermis that insulate is just to intersect with P.e.c. current feed 11 after passing wire through-hole 14.The 3rd embodiment and the 4th embodiment propose two kinds and are different from second embodiment and realize the scheme that current feed 11,12 intersects in signals collecting printed circuit board (PCB) 1.

The utility model the 5th embodiment, as shown in Figure 7, proposing the another kind of current feed 11,12 that makes does not have the ground connection scheme arranged in a crossed manner that is electrically connected mutually.Described signals collecting printed circuit board (PCB) 1 is provided with two and gathers signal connection end point 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 first branch line and current feed second branch line separately.Described two current feeds 11,12 current feed first branch line separately is separately positioned on the two sides of signals collecting printed circuit board (PCB) 1, and be connected electrically between two conductive poles 151, the 161 and two current acquisition pins 131,132, make two current feeds, first branch line not have the ground connection of being electrically connected, arranged in a crossed manner on printed circuit board (PCB) 1.Described two current feeds 11,12 current feed second branch line separately is separately positioned on the two sides of signals collecting printed circuit board (PCB) 1, and be connected electrically in two conductive poles 151,161 and two and gather between the signal connection end point 15,16, make two current feeds, second branch line not have the ground connection of being electrically connected, arranged in a crossed manner on printed circuit board (PCB) 1.Thereby be electrically connected to described collection signal connection end point 15,16 by two current feeds 11, the 12 two current acquisition pins 131,132 with described signals collecting chip 13.Specific to the utility model the 5th embodiment, 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, uses depicted as solid lines, and is connected electrically between current acquisition pin 131 and the 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, and with dashed lines is drawn, and is connected electrically between current acquisition pin 132 and the 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, and with dashed lines is drawn, and is connected electrically between collection signal connection end point 15 and the 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, uses depicted as solid lines, and is connected electrically between collection signal connection end point 16 and the conductive pole 151.Described conductive pole 151 will be separately positioned on first branch line of the current feed 12 on signals collecting printed circuit board (PCB) 1 two sides and second branch line and be electrically connected and be connected into a complete current feed 12, and current feed 12 is electrically connected to current acquisition pin 132 and gathers signal connection end point 16.Described conductive pole 161 will be separately positioned on first branch line of the current feed 11 on signals collecting printed circuit board (PCB) 1 two sides and second branch line and be electrically connected and be connected into a complete current feed 11, and current feed 11 is electrically connected to current acquisition pin 131 and gathers signal connection end point 15.Among the utility model the 5th embodiment, described two current feeds 11,12 can be the two current feed leads that wrapping the epidermis that insulate, it also can be the P.e.c. current feed that is printed on the signals collecting printed circuit board (PCB) 1, certainly can also be that in two current feeds 11,12 one is the two current feed leads that wrapping the epidermis that insulate, another root be the P.e.c. current feed that is printed on the signals collecting printed circuit board (PCB) 1.

The utility model proposes at sampling cotton rope 2 and be electrically connected in the process the following scheme of employing with current sampling resistor device 3, namely described step C can also comprise step by step following,

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

C22. adjust from two current sample leads 21 of the second end, 22 furcations to two a current sample lead 21,22 and the connection end point of current sampling resistor device 3 between two sections current sample leads 21,22 length, on the direction of the longitudinal section of current sampling resistor device 3, make the described current sample lead 21 that is attached on the 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 the current sampling resistor device 3 surrounds, the area vector direction is opposite, makes two current sample leads 21 of the second end of described sampling cotton rope 2, the area vector sum that the 22 ring current loops that constitute with current sampling resistor device 3 surround is zero.

Second embodiment of the utility model by the as shown in Figure 4 cotton rope 2 of realizing sampling is electrically connected scheme with current sampling resistor device 3, two current sample leads 21 of the second end of described sampling cotton rope 2,22 are electrically connected two links of described current sampling resistor device 3 respectively, two current sample leads 21 of described the second end, 22 furcations are arranged on the current sampling resistor 3 position away from described two links, and from two current sample leads 21 of the second end, 22 furcations to two a current sample lead 21,22 and the link of current sampling resistor device 3 between two sections current sample leads 21,22 all are attached to current sampling resistor device 3 surfaces, on the direction of the longitudinal section of current sampling resistor device 3, make the described current sample lead 21 that is attached on the 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 the current sampling resistor device 3 surrounds, the area vector direction is opposite, makes two current sample leads 21 of the second end of described sampling cotton rope 2, the area vector sum that the 22 ring current loops that constitute with current sampling resistor device 3 surround is zero.

As shown in Figure 4, when the electric current in the current sample lead 21 on being attached to current sampling resistor device 3 is mobile by the direction of LP38, the direction that electric current in another current sample lead 22 is just pressed LP39 flows, and then electric current will be mobile to the direction of LP35 by LP37 to LP36 in the equivalent ring current loop that with dashed lines marks in current sampling resistor device 3, this scheme can determine to be attached to current sample lead 21 on the current sampling resistor device 3 by described right-handed helix rule, 22 area of plane vectors that surround are directions outside drawing in the drawing, and the area of plane vector that the equivalent ring current loop that with dashed lines marks in current sampling resistor device 3 surrounds is the direction in the export-oriented drawing of drawing, their directions are opposite, and be attached to current sample lead 21 on the current sampling resistor device 3, the area of plane equal and opposite in direction that the equivalent ring current loop that with dashed lines marks in 22 areas of plane that surround and the current sampling resistor device 3 surrounds, thereby sampling cotton rope 2 is electrically connected the vector of the area of plane that the ring circuit that forms surrounds with current sampling resistor device 3 and be zero, thereby can not produce induction current between cotton rope 2 and the current sampling resistor device 3 sampling.

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

Consider and be applicable to the measurement instrument that generally uses, if described measurement instrument is for the measurement instrument of measuring electric power, also comprise the voltage sample lead 23 that is connected electrically between described signals collecting printed circuit board (PCB) 1 and the current sampling resistor device 3, described two current sample leads 21,22, and voltage sample lead 23 in the shape of a spiral ring-type closely be twisted into a sampling cotton rope 2 with first end and the second end, be voltage sample lead 23 be stranded in the sampling cotton rope 2 in, and with two current sample leads 21,22 in the shape of a spiral ring-type closely twist together.Just voltage sample lead 23 can be stranded with the current sample lead, do not influence current sample lead spiral ring and realize that partly area vector is zero scheme.

Claims (9)

1. measurement instrument with current sample module that not influenced by the alternation external magnetic field, comprise signals collecting printed circuit board (PCB) (1), the current sampling resistor device made from the manganin material (3), and be connected electrically in two current sample leads (21,22) between described signals collecting printed circuit board (PCB) (1) and the 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 leads (21,22); It is characterized in that:

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

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

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

Described area vector refers to the area of plane with direction that surrounded by the 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 the plane.

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

Two current sample leads of the first end of described sampling cotton rope (2) (21,22) are electrically connected two current feeds (11,12) of described printed circuit board (PCB) (1) respectively, and wherein a current sample lead (21) bending is arranged in the printed circuit board (PCB) (1) with being semicircular, makes this root bending be the annulus area that Semicircular current sample lead (21) surrounds

The annulus area equal and opposite in direction that surrounds with two current feeds (11,12), the area vector direction is opposite, thereby the area vector sum that the ring current loop that makes two current sample leads of described first end (21,22) and two current feeds (11,12) form surrounds is zero.

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

Described signals collecting printed circuit board (PCB) (1) is provided with two and gathers signal connection end point (15,16); Described signals collecting chip (13) comprises two current acquisition pins (131,132);

Described two current feeds (21,22) are the two current feed leads that wrapping the epidermis that insulate, and this two current feeds lead is connected electrically in the two current acquisition pins (131,132) and two of signals collecting chip (13) respectively and gathers between the signal connection end point (15,16);

Perhaps, described two current feeds (21,22) are the two P.e.c. current feeds that are printed on the signals collecting printed circuit board (PCB) (1), and this two P.e.c. current feed is connected electrically in the two current acquisition pins (131,132) and two of signals collecting chip (13) respectively and gathers between the signal connection end point (15,16).

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

Described two current feeds (11,12) do not have the ground connection that is electrically connected mutually, are arranged on the printed circuit board (PCB) (1) across;

Two current sample leads (21 of the first end of described sampling cotton rope (2), 22) be electrically connected two current feeds (11 of described printed circuit board (PCB) (1) respectively, 12), the current sample lead (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, the area vector direction is opposite, thereby makes two current sample leads (21 of described first end, 22) with two current feeds (11,12) the area vector sum that surrounds of the ring current loop of Zu Chenging is zero.

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

Described signals collecting printed circuit board (PCB) (1) is provided with two and gathers signal connection end point (15,16), and a wire through-hole (14); Described two current feeds (11,12) do not have the ground connection that is electrically connected mutually, are arranged on the printed circuit board (PCB) (1) across by this wire through-hole (14); Described signals collecting chip (13) comprises two current acquisition pins (131,132);

Described two current feeds (11,22) are the two current feed leads that wrapping the epidermis that insulate, this two current feeds lead is connected electrically in the two current acquisition pins (131,132) and two of signals collecting chip (13) respectively and gathers between the signal connection end point (15,16), and does not have the ground connection that is electrically connected mutually, is arranged on the printed circuit board (PCB) (1) across by described wire through-hole (14);

Perhaps, described two current feeds (11,12) one in is the P.e.c. current feed that is printed on the signals collecting printed circuit board (PCB) (1), another root is the two current feed leads that wrapping the epidermis that insulate, described P.e.c. current feed is connected electrically in the current acquisition pin (131) of signals collecting chip (13) and gathers between the signal connection end point (16), described current feed lead passes described wire through-hole (14) does not have the ground connection of being electrically connected with the P.e.c. current feed, arranged in a crossed manner on printed circuit board (PCB) (1), and described current feed lead is connected electrically between the current acquisition pin (132) and collection signal connection end point (15) of signals collecting chip (13).

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

Described signals collecting printed circuit board (PCB) (1) is provided with two and gathers signal connection end point (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 first branch line and current feed second branch line separately;

Described two current feeds (11,12) current feed first branch line separately is 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 the two current acquisition pins (131,132), make two current feeds, first branch line not have the ground connection of being electrically connected, arranged in a crossed manner on printed circuit board (PCB) (1); Described two current feeds (11,12) current feed second branch line separately is separately positioned on the two sides of signals collecting printed circuit board (PCB) (1), and be connected electrically in two conductive poles (151,161) and two and gather between the signal connection end point (15,16), make two current feeds, second branch line not have the ground connection of being electrically connected, arranged in a crossed manner on printed circuit board (PCB) (1); Thereby by two current feeds (11,12) the two current acquisition pins (131,132) of described signals collecting chip (13) are electrically connected to described collection signal connection end point (15,16);

Described two current feeds (11,12) are the two current feed leads that wrapping the epidermis that insulate, and perhaps, described two current feeds (11,12) are the P.e.c. current feeds that is printed on the signals collecting printed circuit board (PCB) (1).

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

Two current sample leads (21 of the second end of described sampling cotton rope (2), 22) be electrically connected described current sampling resistor device (3) respectively, and wherein a current sample lead (21) attaches and is wrapped in current sampling resistor device (3) surface, on the longitudinal section direction of current sampling resistor device (3), the area equal and opposite in direction that makes current loop that the described current sample lead (21) that is wrapped on the current sampling resistor device (3) surrounds and the ring current loop in the current sampling resistor device (3) surround separately, the area vector direction is opposite, makes two current sample leads (21 of the second end of described sampling cotton rope (2), 22) the area vector sum that surrounds of the ring current loop that constitutes with current sampling resistor device (3) is zero.

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

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

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

Described measurement instrument is for the measurement instrument of measuring electric power, also comprise the voltage sample lead (23) that is connected electrically between described signals collecting printed circuit board (PCB) (1) and the current sampling resistor device (3), described two current sample leads (21,22), and voltage sample lead (23) in the shape of a spiral ring-type closely be twisted into a sampling cotton rope (2) with first end and the second end, be that voltage sample lead (23) is stranded in sampling cotton rope (2), and with two current sample leads (21,22) in the shape of a spiral ring-type closely twist together.

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