A kind of Mine-used I. S Transient Electromagnetic Apparatus receiving antenna
One, technical field:
The utility model belongs to geophysical exploration technology field, relates to a kind of Mine-used I. S Transient Electromagnetic Apparatus receiving antenna.
Two, background technology:
Mine Transient Electromagnetic Method is called for short mine TEM, is a kind of electromagnetism class method of exploration that is widely used in recent years the fields such as the inner water damage detection of spy in advance under coal mine, the detection of roof and floor water damage, lateral wall and workplace.Down-hole transient electromagnetic detecting technical field, both at home and abroad instrument is generally applied diameter and is greater than the multiturn coil of 1 meter as receiving antenna, it is strong that this receiving antenna receives signal, but be easy to be subject to extraneous interference, therefore study faint under a kind of effectively received well and field signal, receiving signal sensitivity is high, have certain antijamming capability and meet the receiving antenna that mine safety requires, for improving, down-hole transient electromagnetic method detection accuracy is significant.
Three, utility model content:
The utility model, in order to solve the weak point in above-mentioned background technology, provides a kind of Mine-used I. S Transient Electromagnetic Apparatus receiving antenna, and it has certain antijamming capability, meets Safety of Coal Mine Production requirement, and it is convenient to measure, and is easy to carry, and detection accuracy is high.
For achieving the above object, the technical solution adopted in the utility model is: a kind of Mine-used I. S Transient Electromagnetic Apparatus receiving antenna, comprise shell, it is characterized in that: in described shell, be provided with coil rack, on described coil rack, be arranged with inductive coil, on inductive coil, be arranged with screen layer, the outside surface of described shell is provided with horizontal bubble instrument, bottom is provided with signal amplification circuit, electric battery and power circuit, described electric battery is connected with power circuit, in described coil rack, is provided with bar magnet;
Described signal amplification circuit comprises signal input module, signal input module is connected with timesharing control module, signal amplification circuit, analog switch and signal output module in turn, and described signal amplification circuit comprises small signal amplification circuit and Large signal amplifier.
Described shell be shaped as down T-shape, overall length is 448mm, material is nylon 1010.
The diameter of described bar magnet is 32 mm, and length is 340 mm, and material is high magnetic conductivity ferrite core material.
The diameter of described inductive coil is 37 mm, and the number of turn is 257 circles.
The material of described screen layer is permalloy.
Described electric battery is ± 7.4 V lithium batteries.
Compared with prior art, the advantage and the effect that the utlity model has are as follows:
1, the utility model can effectively improve the sensitivity of receiving antenna, and there is variable-gain functionality, the signal of different sizes is realized to segmentation to be amplified, for stronger signal employing in early stage low gain, amplify, for later stage feeble signal, adopt plus and blowup, guaranteed the collection of useful signal, improved the signal to noise ratio (S/N ratio) of signal, for carrying out accurately transient electromagnetic method detection, laid the foundation;
2, the utility model adopts intrinsic safety type power circuit, has two-stage circuit overcurrent protection function, and preventing the large electric current spark that causes because of fault has increased the security performance under coal mine;
3, to adopt the structure of miniaturization to have weight little for the utility model, is convenient for carrying, and can effectively improve the work efficiency of underground construction;
4, the utility model, according to the detection direction of the adjustable receiving antenna of horizontal bubble instrument, effectively improves detection accuracy;
5, the utility model adopts the ferrite magnetic core material loading of high magnetic permeability to answer the mode of coil, the sensitivity that can effectively improve receiving antenna;
6, at inductive coil, increase permalloy screen layer outward, can effectively shield outside electromagnetic interference, improve Signal-to-Noise.
Four, accompanying drawing explanation:
Fig. 1 is structural representation of the present utility model;
Fig. 2 is signal amplification circuit principle schematic of the present utility model;
Fig. 3 is signal amplification circuit figure of the present utility model;
Reference numeral: 1-shell, 2-electric battery, 3-power circuit, 4-signal amplification circuit, 5-coil rack, 6-inductive coil, 7-screen layer, 8-bar magnet, 9-air-bubble level, 10-signal input module, 11-timesharing control module, 12-analog switch, 13-signal output module, 14-small signal amplification circuit, 15-Large signal amplifier.
Five, embodiment:
Below in conjunction with the drawings and specific embodiments, the utility model is elaborated:
Referring to Fig. 1: a kind of Mine-used I. S Transient Electromagnetic Apparatus receiving antenna, comprise shell 1, the outside surface of shell 1 is provided with horizontal bubble instrument 9, shell 1 be shaped as down T-shape, overall length is 448mm, in described shell 1, be provided with coil rack 5, on described coil rack 5, be arranged with inductive coil 6, the diameter of described inductive coil 6 is 37 mm, and the number of turn is 257 circles, on inductive coil 6, be arranged with screen layer 7, the material of described screen layer 7 is permalloy; The bottom package of described shell 1 has signal amplification circuit 4, electric battery 2 and power circuit 3, and described electric battery 2 is connected with power circuit 3, for circuit provides intrinsic safety type power supply, electric battery 2 is ± 7.4V lithium battery, by intrinsic safety type power circuit 3, provide ± 5V, maximum short circuit current is 165mA.In described coil rack 5, be provided with bar magnet 8, the diameter of described bar magnet 8 is 32 mm, and length is 340 mm, and material is high magnetic conductivity ferrite core material.
Referring to Fig. 2: described signal amplification circuit 4 comprises signal input module 10, signal input module 10 is connected with timesharing control module 11, signal amplification circuit, analog switch 12 and signal output module 13 in turn, and described signal amplification circuit comprises small signal amplification circuit 14 and Large signal amplifier 15.
Described shell connecting coil skeleton 5 one end diameters are 62 mm, and length is 340 mm, connect electric battery 2 and long 126 mm in circuit board 3 one end, wide 98 mm, and high 62 mm, shell adopts Nylon-1010, has very strong physical strength.
After the sensed coil 6 of secondary field signal receives, under the effect of high magnetic conductivity ferrite core material 8, signal increases, and by signal amplification circuit 4, signal is exported.
After electric battery 2 access power circuits, through dual-electrode protecting circuit, then carry out voltage transformation, then output.
After the sensed coil 6 of secondary field signal receives, through time division control circuit, small-signal is carried out to 100 or 1000 times of amplifications, large-signal is carried out to 1 or 10 times of amplification, then by analog switch, control, signal is exported.
Battery voltage, through after the protection of two-stage constant current tube, is sent into power supply chip U3, U4 and is carried out voltage transformation, obtain receiving antenna system required ± 5V voltage.
Referring to Fig. 3: after the sensed coil of secondary field signal receives, send into amplifier circuit U8, U9, under the control of multi-way switch K1, stronger signal is in early days carried out to 1 or 10 times of amplification, to late period feeble signal carry out 100 or 1000 times of amplifications, thereby the acquisition precision that has improved useful signal, has improved signal to noise ratio (S/N ratio).
In actual applications, inductive coil 6 can adopt diameter 0.5mm enameled wire to make, and screen layer 7 adopts permalloy to make.
Through experimental test, new type mining intrinsic safety type Transient Electromagnetic Apparatus receiving antenna of the present utility model has wider frequency band (0~100 kHz), and can be according to the power of signal, to early stage signal carry out 1,10 times, the signal of 100,1000 times of later stage signals is amplified.
Transient Electromagnetic Apparatus receiving antenna frequency response method of testing, utilize external wire frame to form 0.7 meter of diameter, the air core coil of the number of turn 40 circles, in coil, input the swept-frequency signal of 100mA electric current, output terminal at Transient Electromagnetic Apparatus receiving antenna is observed the response to excitation signal with oscillograph, swept frequency range 0-200KHz, the difference that the output amplitude of antenna drops to 10% corresponding two dot frequencies of peak response frequency is defined as the frequency response range of receiving antenna, 0-200KHz in figure, the output signal of antenna is stronger, within its amplitude belongs to the frequency response range of receiving antenna.