CN204116582U - Transient magnetic field differential transducer - Google Patents
Transient magnetic field differential transducer Download PDFInfo
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- CN204116582U CN204116582U CN201420351524.0U CN201420351524U CN204116582U CN 204116582 U CN204116582 U CN 204116582U CN 201420351524 U CN201420351524 U CN 201420351524U CN 204116582 U CN204116582 U CN 204116582U
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- concentric cable
- differential transducer
- transient magnetic
- shield pipe
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Abstract
The utility model is a kind of transient magnetic field differential transducer, comprises a tours antenna support portion, an electromagnetic shield pipe and an electromagnetic screen output cassette and is interconnected to form a housing.This transient magnetic field differential transducer comprise further two concentric cable be symmetrically set in described housing formed one sensing antenna.One end of two concentric cable is arranged in described tours antenna support portion, and the other end of two concentric cable enters electromagnetic screen output cassette through described electromagnetic shield pipe, and is separated extraction from described electromagnetic screen output cassette.In described tours antenna support portion, described two concentric cable surround half closed ring coil symmetrically and the end points interval of these two concentric cable is arranged.At the end points of the spaced setting of described two concentric cable, the coaxial cable core of any one cable is connected by conducting electricity with the screen layer of another one coaxial cable.
Description
Technical field
The utility model relates to a kind of sensor, is related specifically to a kind of transient magnetic field differential transducer.
Background technology
Along with the progress of science and technology, increasing electronic equipment can produce transient electromagnetic field, and this transient electromagnetic field can produce electromagnetic interference (EMI) to other electronic equipment, becomes interference source.Therefore, how to detect these interference sources and intensity thereof thus take protection and shielding measure just to seem more and more urgent.And utilize transient magnetic field sensor detection transient magnetic field just can realize this goal.
According to different physical laws or physical phenomenon, such as magnetic induction, galvanomagnetic effect, nucleon motion, superconductive quantum interference, magnetic effect and magneto-optic effect etc., can produce the magnetic field sensor of different characteristics.They be applicable to detect magnetic field intensity different, also have different sensitivity, Frequency Response and suitable application area.This wherein, can measure the magnetic field of high frequency, high strength with the transient magnetic field differential transducer that Faraday's electromagnetic induction law makes, be comparatively ideal high power transient magnetic field sensor.
This sensor is the electric field utilizing the magnetic field induction of change to go out to induct, and produces measurable hoop electric potential difference.Meeting inductive coil small size, when namely much smaller than the wavelength that the highest frequency of variation magnetic field is corresponding, the average magnetic field rate of change in measured zone and the rate of change of magnetic approximately equal of its central point.So can carry out with the induced voltage that induction necklace produces the rate of change of magnetic that indirect inspection goes out this regional center place, then by carrying out to it magnetic field intensity that Integral Processing just can obtain this point.But, because the electric field that all exists in the magnetic field environment of reality can produce interference effect to the voltage signal of induction, the interference effect of how electric field shielding is become determine transient magnetic field differential transducer whether can the key factor of Measurement accuracy field signal.
Utility model content
In order to overcome the interference effect of electric field to the impact of transient magnetic field differential transducer, the utility model provides the high power transient magnetic field differential transducer of a kind of concentric cable as magnetic field induction antenna.It can effectively avoid electric field on the impact of magnetic-field measurement, can also obtain higher bandwidth simultaneously.
The utility model solves the technical scheme that its technical matters adopts: a kind of transient magnetic field differential transducer, comprises a tours antenna support portion, an electromagnetic shield pipe and an electromagnetic screen output cassette and be interconnected to form a housing.This transient magnetic field differential transducer comprise further two concentric cable be symmetrically set in described housing formed one sensing antenna.One end of these two concentric cable is arranged in described tours antenna support portion, and the other end of these two concentric cable enters electromagnetic screen output cassette through described electromagnetic shield pipe, and is separated extraction from described electromagnetic screen output cassette.In described tours antenna support portion, described two concentric cable surround half closed ring coil symmetrically and the end points interval of these two concentric cable is arranged.At the end points of the spaced setting of described two concentric cable, the coaxial cable core of any one cable is connected by conducting electricity with the screen layer of another one coaxial cable.
Described tours antenna support portion comprises two lids of symmetrical fastening, each top surface is provided with semi-closed ring connected in star, the groove of this annular has a breach, after the semi-closed ring connected in star fastening of described two lids, the breach of the semi-closed ring connected in star of described two lids forms an opening.
In the annular groove being arranged on described top surface of the spaced symmetry in one end of described two concentric cable, surround described semiclosed toroid winding, the other end of described two concentric cable is drawn from the described opening that the breach of the semi-closed ring connected in star of described two lids is formed.
The other end of described two concentric cable is drawn from described opening and is entered described electromagnetic shield pipe, described two concentric cable are parallel to each other in described electromagnetic shield pipe inside, and the extended line of described electromagnetic shield pipe central shaft divides described semiclosed toroid winding equally, and cross this semiclosed toroidal center.
Comprise an electromagnetic screen adapter further, this electromagnetic screen adapter mates mutually with one end of described opening and described electromagnetic shield pipe, is fixed in one end of described electromagnetic shield pipe and described tours antenna support portion, composition enclosed construction.
Described electromagnetic screen output cassette has relative first end and the second end, described first end has an input hole, described second end has two delivery outlets, the other end of described electromagnetic shield pipe is fixed on the first end of described electromagnetic screen output cassette, and form enclosed construction with described electromagnetic screen output cassette, described two concentric cable enter described electromagnetic screen output cassette by described input hole, and draw from described two delivery outlets respectively.
Comprise two SMA connectors further and be fixed on described two delivery outlets, the part that described two concentric cable are drawn at the delivery outlet of described electromagnetic screen output cassette is electrically connected with described SMA connector.
Described semi-enclosed toroidal shape is square, rectangle, triangle, trapezoidal, circular or oval.
Compared with the prior art, the shielding action that the utility model high power transient magnetic field differential transducer make use of concentric cable dexterously overcomes the interference of electric field, the voltage signal induced through co-axial cables transport out.Meanwhile, compare common small loop antenna, the output signal of this transient magnetic field differential transducer is when being connected with the checkout equipment such as oscillograph, and directly with SMA connector, effectively the decay of reduction signal and anti-stop signal distort.And the same with general passive device, there is not the upper limit of the magnetic field intensity of measurement in this sensor itself.
Accompanying drawing explanation
Fig. 1 is the structural representation of the utility model transient magnetic field differential transducer.
Fig. 2 is the decomposition chart of the utility model transient magnetic field differential transducer.
Fig. 3 is the structural representation in the antenna mounting portion of the utility model transient magnetic field differential transducer.
Fig. 4 is the structural representation of the lid in the antenna mounting portion of the utility model transient magnetic field differential transducer.
Fig. 5 is the electromagnetic screen adapter of this novel transient magnetic field differential transducer and the structural representation of electromagnetic shield pipe.
Fig. 6 is the structural representation of the electromagnetic screen output cassette of the utility model transient magnetic field differential transducer.
Fig. 7 is the decomposition texture schematic diagram of the electromagnetic screen output cassette of the utility model transient magnetic field differential transducer.
Fig. 8 is the schematic diagram of the fixed head between the electromagnetic screen output cassette of the utility model transient magnetic field differential transducer and electromagnetic shield pipe.
Fig. 9 is the distribution of current schematic diagram that magnetic field antenna made by concentric cable.
Figure 10 is the principle schematic of the sensing antenna of the utility model transient magnetic field differential transducer.
Figure 11 is the equivalent circuit diagram of the utility model transient magnetic field differential transducer.
Figure 12 is the simplification circuit of the utility model transient magnetic field differential transducer.
Figure 13 is the magnetic field sensor output voltage waveforms (oscilloscope display) of the utility model transient magnetic field differential transducer.
Figure 14 be the utility model transient magnetic field differential transducer output signal integration before and after waveform.
Figure 15 is the figure sensitivity calibration curve of the utility model transient magnetic field differential transducer.
Figure 16 be the utility model transient magnetic field differential transducer output signal integration before and after waveform enlarged drawing.
Main element symbol description
Tours antenna support portion 10
Electromagnetic shield pipe 20
Ring screw 22
Electromagnetic screen output cassette 30
Electromagnetic screen adapter 60
Through hole 62
Metal fixing plate 70
First fixed orifice 72
Second fixed orifice 74
Sensing antenna 80
Transient magnetic field differential transducer 100
Lid 110
Square groove 112
Extending flute 114
Semi-closed ring connected in star 115
Breach 116
Opening 120
Lid 130
Enclosure space 300
Housing 310
Input hole 312
3rd fixed orifice 313
Delivery outlet 316
Concentric cable 810
Wire 812
Following embodiment will further illustrate the utility model in conjunction with above-mentioned accompanying drawing.
Embodiment
Below in conjunction with drawings and Examples, the utility model is further elaborated, with reference to accompanying drawing.Should be understood that these embodiments are only not used in restriction scope of the present utility model for illustration of the utility model.In addition should be understood that those skilled in the art can make various changes or modifications the utility model, and these equivalent form of values fall within the application's appended claims limited range equally after the content of having read the utility model instruction.
Refer to Fig. 1 and Fig. 2, the utility model provides a kind of transient magnetic field differential transducer 100, and it comprises tours antenna support portion 10, electromagnetic shield pipe 20, electromagnetic screen output cassette 30 and a sensing antenna 80.Described tours antenna support portion 10, described electromagnetic shield pipe 20, and described electromagnetic screen output cassette 30 is interconnected to form a shell structure.Described sensing antenna 80 comprises two concentric cable 810 and is symmetrically set among described shell structure.Interval, one end symmetry of described two concentric cable 810 surrounds half closed ring coil and is arranged at described tours antenna support portion 10.Only at an end points of described two concentric cable 810, the cable core of any one concentric cable 810 is electrically connected by wire with the screen layer of another one cable.The other end of described two concentric cable 810 enters electromagnetic screen output cassette 30 through described electromagnetic shield pipe 20, and is separated extraction from described electromagnetic screen output cassette 30.
Refer to Fig. 3, described tours antenna support portion 10 is the structure of hollow, for receiving and fixing the semiclosed toroid winding that described two concentric cable 810 surround.This tours antenna support portion 10 has mutually isostructural lid 110 by two and mutually fastens and formed.The side in this annular brace portion 10 has an opening 120, for drawing described two concentric cable 810.
Refer to Fig. 4, for plane has, certain thickness sheet material is formed described lid 110, and a surface of this lid 110 is provided with the semi-closed ring connected in star 115 of certain depth.This semi-closed ring connected in star 115 has two symmetrically arranged extending flutes, 114, square groove 112, and a breach 116.Two extending flutes 114 are communicated with by described square groove 112.Described breach 116 is symmetrical arranged with described square groove 112.After relatively being fastened on the surface that described two lids 130 are formed with semi-closed ring connected in star 115, form described tours antenna support portion 10, described two breach 116 mutually fastened form an opening 120.The fixed form of described two lids 130 is not limit, and can fix with cementing agent, and machinery also can be adopted fixing, as the mode of rivet or buckle, or also can form an entirety by integrated mode.
Be appreciated that the shape of above-mentioned tours antenna support portion 10 and semi-closed ring connected in star 115 thereof is not limit, the semiclosed toroidal shape coordinating described sensing antenna 80 to be formed and size are selected.The shape of this semi-closed ring connected in star 115 can be square, rectangle, triangle, trapezoidal, circular or oval.This tours antenna support portion 10 is made for insulating material, its objective is to receive and fixing the semiclosed toroid winding that described two concentric cable 810 are formed.Because the sensitivity of sensing magnetic fields antenna 80 is directly related with its semiclosed toroidal area, therefore in order to allow semiclosed toroidal shape and area remain unchanged, need certain stationary installation.And this device can not the magnetic field surveyed of disturbing magnetic field antenna, so have certain requirement to the electrical characteristics of its material.Therefore, the insulating material that this tours antenna support portion 10 should be hardness stronger is made, as nylon 6, and nylon66 fiber, epoxy plate, bakelite plate, teflon, organic glass etc.The insulating material of high strength can not be out of shape in the present embodiment, this tours antenna support portion 10 and semi-closed ring connected in star 115 thereof are circular, its material is teflon, because its specific inductive capacity is all very low in very wide frequency range, so very little on the impact of electromagnetic field, and physical strength is enough high.
Described concentric cable 810 comprises cable core, and around the electro-magnetic screen layer of cable core, has good electromagnetic shielding action for electromagnetic field.Described two concentric cable 810 are symmetricly set in described semi-closed ring connected in star 115, form half closed ring coil.Each concentric cable 810, from the square groove 112 of this semi-closed ring connected in star 115, is arranged along a described extending flute 114, and is drawn from described breach 116.The end points of described two concentric cable 810 is oppositely arranged at described square groove 112 interval.The cable core of any one concentric cable 810 is electrically connected by wire 812 in described square groove 112 with the screen layer of another one concentric cable 810, and this square groove 112 is for receiving described wire 812.
Described two concentric cable 810 enter in described electromagnetic shield pipe 20 after drawing from the opening 120 of described tours antenna support portion 10.One end of this electromagnetic shield pipe 20 is connected with the opening 120 of described tours antenna support portion 10.This electromagnetic shield pipe 20 has electromagnetic shielding action, described concentric cable 810 can be prevented to be subject to the interference of external electromagnetic field, affect Signal transmissions.The two ends of electromagnetic shield pipe 20 can be provided with ring screw 22, for being connected with described tours antenna support portion 10 and electromagnetic screen output cassette 30.The material of this electromagnetic shield pipe 20 described is metal, as gold, silver, copper, iron, aluminium etc.Described concentric cable 810 linearly extends in described electromagnetic shield pipe 20, and its extension line is divided equally, the area at described semiclosed toroid winding place.In one embodiment, this electromagnetic shield pipe 20 is aluminum pipe.
Refer to Fig. 5, this electromagnetic shield pipe 20 can be connected and fixed by an electromagnetic screen adapter 60.Electromagnetic screen adapter 60 has a through hole 62.One end of this electromagnetic screen adapter 60 is mated mutually with the opening 120 of described tours antenna support portion 10, thus can be fixed on described tours antenna support portion 10.Other end through hole 62 inside surface of described electromagnetic screen adapter 60 can form internal thread, thus mutually mates with the ring screw 22 of described electromagnetic shield pipe 20 one end, makes one end of described electromagnetic shield pipe 20 be fixed on electromagnetic screen adapter 60.Thus described two concentric cable 810 can enter this through hole 62 from the opening 120 of described tours antenna support portion 10, and enter in described electromagnetic shield pipe 20.The material of this electromagnetic screen adapter 60 is identical with described electromagnetic shield pipe 20.
Refer to Fig. 6 and Fig. 7, described electromagnetic screen output cassette 30 has mutually isostructural housing 310 by two and forms, and described two housings 310 are mutually fastened and define an enclosure space 300.There is in the side of this electromagnetic screen output cassette 30 input hole 312, in the relative side of this electromagnetic screen output cassette 30, there are two delivery outlets 316.Described input hole 312 is fixed in one end of described electromagnetic shield pipe 20, is communicated with described electromagnetic screen output cassette 30, thus described two concentric cable 810 are introduced in electromagnetic screen output cassette 30, and draws respectively from described two delivery outlets 316.Described electromagnetic shield pipe 20 is not limit with the fixed form of this electromagnetic screen output cassette 30, can fix with cementing agent, also machinery can be adopted fixing, as the mode of rivet or buckle, or also can form an entirety with described electromagnetic screen output cassette 30 by integrated mode.The material of this electromagnetic screen output cassette 30 is identical with described electromagnetic shield pipe 20.
Refer to Fig. 8, described electromagnetic shield pipe 20 can be fixed on by a metal fixing plate 70 side that described electromagnetic screen output cassette 30 is formed with input hole 312.This metal fixing plate 70 has 4 the first fixed orifices 72, and 1 the second fixed orifice 74.Second fixed orifice 74 of this metal fixing plate 70 is corresponding with the input hole 312 of described electromagnetic screen output cassette 30, and 4 the first fixed orifices 72 are corresponding with 4 the 3rd fixed orifices 313 that described electromagnetic screen output cassette 30 is formed on the side of input hole 312.One end that electromagnetic shield pipe 20 is formed with ring screw 22 can be fixed in the second fixed orifice 74 of described metal fixing plate 70.Described metal fixing plate 70 is screwed in the side that described electromagnetic screen output cassette 30 is formed with input hole 312.Be appreciated that two delivery outlets 316 of this electromagnetic screen output cassette 30 can arrange SMA interface respectively, thus described two concentric cable 810 can be directly connected with external instrument.
Refer to Fig. 9, because the electric conductivity of the metal screen layer of concentric cable 810 is fine, make its thickness d be greater than several skin depth δ, then electromagnetic field of high frequency only has an impact to the skin of metal screen layer, and does not act on the inner wire of its internal layer and concentric cable 810.Like this, the electric current that the screen layer skin participating in the concentric cable 810 of magnetic field induction produces and its internal layer electric current can not mixed flows.In accompanying drawing 9,1,3 represent metal screen layer, and the dotted line in their regions represents separatrix two-layer inside and outside screen layer, and 2 is inner wires.I
1and i
2the electric current of composition coaxial transmission line, i
3then represent the electric current that changes of magnetic field induces, be also radiation current.
Refer to Figure 10, for high frequency magnetic field, the sensing magnetic fields antenna 80 of the utility model transient magnetic field differential transducer, the shield external layer A → C → B of its concentric cable 810 forms the magnetic field antenna of ring-type, obtains magnetic induction voltage U
aB(representing external shielding layer voltage), to having U
a " B "(representing internal shield voltage), both are completely equal.Like this, A1 and A ", B1 and B " is the voltage signal inputs of left and right concentric cable 810 respectively, through symmetrical coaxial transmission line, outputs to E and F, and the output terminal formed with D.
Suppose E and F, meet load ZL1 and ZL2 respectively with their common port D (ground connection), then the equivalent electrical circuit of drawings attached 11.In Figure 11, Z1 and Z2 represents the outer impedance produced as magnetic field antenna of metallic shield of the right and left concentric cable respectively.If left and right Striking symmetry, Z1=Z2=0.5Z, Z are its total impedances, comprise inductance and resistance.When ring radius R compares the wavelength X of measured magnetic field highest frequency component
minenough hour, General Requirements ring semi-perimeter and electrical length θ < 10 ° corresponding to l/2,
Then the reactance of Z is far longer than resistance, and the approximate value of the induction reactance that its inductance L available produces replaces Z.
L approximate value:
Because screen layer does not have electric current diametrically, so ectonexine equipotentiality diametrically in fig. 3.Because CA1 (or the screen layer skin of the concentric cable of CA ") section is magnetic field antenna, so this section of screen layer not equipotentiality, this understanding for voltage signal transmission in accompanying drawing 3 is very important.And the coaxial cable shielding layer of CE (or CD) section is equipotentiality, equal ground connection.Again by the screen layer internal layer of concentric cable and the transmission line of inner wire composition, obtain
U
A1A″＝U
ED＝U
BA
In like manner also have,
U
B″B1＝U
DF＝U
BA
Obtain output voltage,
U＝U
EF＝U
ED-U
FD＝U
BA-(-U
BA)＝2U
BA (3)
Therefore to the magnetic field meeting (1) expression formula, Z ≈ Z
l.If also have ZL1=ZL2=Z0, Z0 to be the characteristic impedance of concentric cable.If load matched, then just like the simplification circuit of accompanying drawing 12.
Based on accompanying drawing 12, expressing formula to output voltage, to carry out Fourier analysis as follows:
By output expression formula:
Obtain transport function
Can prove, if
Then
Transport function can be reduced to simultaneously
H(jω)≈2Ajωe
ja(ω)
U (j ω)=H (j ω) B (j ω) Fourier's inversion is obtained,
So output signal U (t) is the differential after input magnetic field B (t) postpones 2L/Z0, and amplitude 2A is exactly sensitivity.
Prerequisite above about the analysis of transient magnetic field differential transducer principle of work is all that the outer field skin effect of coaxial cable shielding layer makes magnetic field cannot enter the inner wire of concentric cable.And for the very low frequency (VLF) composition in magnetic field, skin effect is not remarkable, magnetic field can enter inner wire through the metal screen layer of concentric cable, and analysis meeting is different.But know that now magnetic field antenna deteriorates to two simple conductor loops, i.e. B → C → A → B1 → A1 → B with reference to accompanying drawing 9, but output expression formula (6) when the magnetic induction output voltage noticing at this moment goes to zero with ω in (5) is just unified.
Owing to no matter being high frequency or low-frequency current field, concentric cable metal screen layer can both be shielded effectively, so know that electric field is a closed circle to the reach of transient magnetic field differential transducer just with reference to accompanying drawing 9, if electric field frequency also meets the constraint formula of (1), electric field would not be measured by disturbing magnetic field.
When magnetic field sensor designs, topmost two indices is its bandwidth sum sensitivity, and for high power transient magnetic field sensor, first will consider whether the bandwidth of magnetic field sensor satisfies the demand, and allows the sensitivity of sensor more high better on this basis.Provide the specific design flow process requiring sensor bandwidth at more than 100MHz below:
Known by principle analysis above, this novel transient magnetic field differential transducer 100 needs when bandwidth Design to consider following bandwidth constraint relational expression,
Like this, by selecting rational R, r and Z0 (general 50 Ω), the magnetic field sensor of respective bandwidth can just be designed.Wherein r, the i.e. external radius of concentric cable metal screen layer, selection need consider the actual size that can buy.The model such as selecting Harbour Industries to produce is the concentric cable of SS405, its metallic shield outer diameter D=2.11mm, then r=1.05mm, and characteristic impedance is 50 Ω; Design R=7.5mm, then estimate the bandwidth BW=f0=124MHz designed, sensitivity S=2A=353mm2.
The transient magnetic field differential transducer 100 that the utility model provides can be calibrated, mainly the sensitivity of calibrating sensors and bandwidth by standard transverse electromagnetic wave generating means gtem cell.In an experiment, photo transmission system is added in transient magnetic field differential transducer 100 rear end so that signal long-distance transmission is unattenuated.
Main result refers to Figure 13 to Figure 16.Figure 13 is for being 100V respectively range value U0, and the square wave pulse voltage of 200V, 500V, 1000V, 1500V, 2000V inputs gtem cell.Figure 14 is waveform before and after output signal integration, and wherein inputting square-wave voltage amplitude is 2kV, and pulsewidth is 50ns, realizes the integration operation of output voltage signal by the method for numerical integration.Figure 15 is the figure sensitivity calibration curve of the utility model transient magnetic field differential transducer, wherein linearly dependent coefficient R=0.9994, the input voltage that horizontal ordinate represents to be converted into the magnetic field intensity B in gtem cell, in coordinate, U0 represents input square wave amplitude, and h represents the vertical height of sensor measurement point in gtem cell.Figure 16 be the utility model transient magnetic field differential transducer output signal integration before and after waveform enlarged drawing.In Figure 16, " square wave " fall time (rise time in the corresponding input pulse magnetic field) τ 1 that integration obtains is no more than 2ns, estimate its bandwidth BW=0.35/ τ 1 ≈ 175MHz, the 124MHz estimated when this value is greater than design, the bandwidth of magnetic field sensor at more than 100MHz, should reach re-set target.
Compare the magnetic field differential transducer that common small loop antenna is formed, the shielding action that the utility model high power transient magnetic field differential transducer make use of concentric cable dexterously overcomes the interference of electric field, the voltage signal induced through co-axial cables transport out.Meanwhile, compare common small loop antenna, the output signal of this transient magnetic field differential transducer is when being connected with the checkout equipment such as oscillograph, and directly with SMA connector, effectively the decay of reduction signal and anti-stop signal distort.And the same with general passive device, there is not the upper limit of the magnetic field intensity of measurement in this sensor itself.
Claims (8)
1. a transient magnetic field differential transducer, comprise a tours antenna support portion, one electromagnetic shield pipe and an electromagnetic screen output cassette are interconnected to form a housing, it is characterized in that, this transient magnetic field differential transducer comprise further two concentric cable be symmetrically set in described housing formed one sensing antenna, one end of these two concentric cable is arranged in described tours antenna support portion, the other end of these two concentric cable enters electromagnetic screen output cassette through described electromagnetic shield pipe, and be separated extraction from described electromagnetic screen output cassette, in described tours antenna support portion, described two concentric cable surround half closed ring coil symmetrically and the end points interval of these two concentric cable is arranged, at the end points of the spaced setting of described two concentric cable, the coaxial cable core of any one cable is connected by conducting electricity with the screen layer of another one coaxial cable.
2. transient magnetic field differential transducer as claimed in claim 1, it is characterized in that, described tours antenna support portion comprises two lids of symmetrical fastening, each top surface is provided with semi-closed ring connected in star, the groove of this annular has a breach, after the semi-closed ring connected in star fastening of described two lids, the breach of the semi-closed ring connected in star of described two lids forms an opening.
3. transient magnetic field differential transducer as claimed in claim 2, it is characterized in that, in the annular groove being arranged on described top surface of the spaced symmetry in one end of described two concentric cable, surround described semiclosed toroid winding, the other end of described two concentric cable is drawn from the described opening that the breach of the semi-closed ring connected in star of described two lids is formed.
4. transient magnetic field differential transducer as claimed in claim 3, it is characterized in that, the other end of described two concentric cable is drawn from described opening and is entered described electromagnetic shield pipe, described two concentric cable are parallel to each other in described electromagnetic shield pipe inside, and the extended line of described electromagnetic shield pipe central shaft divides described semiclosed toroid winding equally, and cross this semiclosed toroidal center.
5. transient magnetic field differential transducer as claimed in claim 4, it is characterized in that, comprise an electromagnetic screen adapter further, this electromagnetic screen adapter mates mutually with one end of described opening and described electromagnetic shield pipe, one end of described electromagnetic shield pipe and described tours antenna support portion are fixed, composition enclosed construction.
6. transient magnetic field differential transducer as claimed in claim 5, it is characterized in that, described electromagnetic screen output cassette has relative first end and the second end, described first end has an input hole, described second end has two delivery outlets, the other end of described electromagnetic shield pipe is fixed on the first end of described electromagnetic screen output cassette, and form enclosed construction with described electromagnetic screen output cassette, described two concentric cable enter described electromagnetic screen output cassette by described input hole, and draw from described two delivery outlets respectively.
7. transient magnetic field differential transducer as claimed in claim 6, it is characterized in that, comprise two SMA connectors further and be fixed on described two delivery outlets, the part that described two concentric cable are drawn at the delivery outlet of described electromagnetic screen output cassette is electrically connected with described SMA connector.
8. transient magnetic field differential transducer as claimed in claim 1, is characterized in that, described semi-enclosed toroidal shape is square, rectangle, triangle, trapezoidal, circular or oval.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420351524.0U CN204116582U (en) | 2014-06-26 | 2014-06-26 | Transient magnetic field differential transducer |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420351524.0U CN204116582U (en) | 2014-06-26 | 2014-06-26 | Transient magnetic field differential transducer |
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| CN110531285A (en) * | 2019-09-26 | 2019-12-03 | 清华大学 | A kind of Multiple level transient magnetic field sensor |
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| CN110531285A (en) * | 2019-09-26 | 2019-12-03 | 清华大学 | A kind of Multiple level transient magnetic field sensor |
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