SU1594472A1 - Geophone - Google Patents

Abstract

The invention relates to geophysics and seismology and can be used to register elastic vibrations. The purpose of the invention is to expand the frequency range of the recording of seismic vibrations and the natural frequency of the geophone in the direction of infra-low frequencies. An inductive displacement transducer is inserted into an electrodynamic seismic receiver that records the speed of movement, recording the amplitude of movement of the body of the geophone relative to an inert mass. The inertial mass parameters (natural frequency and attenuation) are controlled remotely by introducing into the control coils of an electrodynamic geophone a feedback signal from the output of the displacement meter. In this case, the input of the displacement meter is a plate-modulator, the first end of which is rigidly connected to the inert mass, and the second end is inserted into the air gap of the core of the inductive sensor displacement meter. 1 hp f-ly, 4 ill.

Description

 The invention relates to geophysics and seismic studies and can be used in the regression of elastic magnetic fields.

The purpose of the invention is the expansion of the frequency range of the recording of seismic oscillations and the natural frequency of the seismic receiver in the direction of infra-low frequencies.

FIG. I shows the block diagram of the proposed samopriemnik a; on 4y1g. 2 - inductive transducer with} on. FIG. 3 - schematic diagram of displacement gauges; in FIG. 4 - output voltage drop.

The seismic receiver (ir, 1) contains body I, this receiver, body 2 displacement meter, spring 3, ground mass 4, modular 5 modulator 5, core 6 with air gap 7 and differential windings 9: electrical circuit 10 of the generator you-- low frequency with output circuit .11 and. output voltage divider 12, external unit 13 control1, control coils 14 and 15, working induction coil 16, damping induction coil 17, magnetic system 18, external recording unit 19, displaceable speed, external unit 20

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registering the neip card and the block 21

Case 1 of the seismic receiver is rigidly connected: case 2 of the displacement meter and the mass system 18, and the earth mass 4 of the seismic receiver | is rigidly connected to the induction coils 14-17 unit, magnetic, and with the plate -mo-; dultor 5 ,. introduced into the internal gap 7 of the core 6, at the ends of which {coyo there are coaxially fixed differential winding 8 and 9 Hfig. 2). When exposed to elastic vibrations, the movement of the magickal system 18 relative to the coils of the C-17 excites emf in them. I the Coil 16 is connected to the input of the I19 recording unit of the movement speed i I and the coil i 7 in order to provide the necessary I attenuation of the inert masoe 14 by the shunt resistor or, if necessary. can be connected in turn with a coil of 14 or 15 f to enhance the effect of the feedback, 1 with the recorded amplitude of you; the signal from the coil 16 is proportional to the speed and at the same time; I amplitude of movement of the corsus of the seismic i receiver. Air movement; Zora 7 with respect to the modular ppastiny ira 5 changes the equivalent inductance: the winding 8 and 9, and the increase is; the inductive effect of the first winding 8; Bent approximation to it plate-mo-; The inductance of the second winding 9 was able to blew toby 5 by the same amount by removing the modulator-modulator from it.

 The ends of the windings 8 and 9 are connected to a medical circuit 10 (FIG. 3), which. made in the form of a displacement meter and is a high frequency generator in the course of which the jets and windings 8 and capacitors 22 and 23 are included. The positive feedback necessary for the generation is carried out by the elements 24 and 25. The capacitances 22 and 23 are connected to the collectors of transistors 26 and 27. The output "circuit 11 is formed by emitter loads 28 and i9, made in the form of PC filters with a blocking capacitor 30, the input of the body movement detection unit 20 is connected to currents 31 and 32, respectively. inert mass A to point 33 and 34 - the source of 21 pITann. Electric circuit as a whole presents em

20

25

. Q J5 -30

Jq. .

35

40

45

the measuring bridge, the symmetrical shoulders of which form the elements 8 22-29 and 9.23-28, and the diagonal of the bridge forms the supply circuit - points 33 and 34 and the output chain - points 3 and 32,

The seismic receiver works in the following way,

When a modulator plate 5 is inserted in the middle of the air gap 7, the shoulders of the bridge remain balanced (potential difference at the points. PZ and 32 is absent) and the point in the middle of the gap is spatial HyjijBM, formed as a result of the interaction of the high-frequency electro-magnetic fields of the windings 8 and 9 directed toward each other, the extension of the spatial zero relative to the plate-modulator disrupts the balance of the bridge shoulders and a constant voltage is generated at the output, the polarity of which changes according to With the direction of movement of the spatial zero relative to the plate-modulator 5, the amplitude of the output signal varies in proportion to the amplitude of movement of the body of the seismic receiver relative to the inert mass 4 and does not depend on the speed of movement,

For the purpose of controlling the dynamic characteristics of the inertial mass 4, a divider 12 of the output and voltage was inserted into the seismic receiver (FIG. 4), which was completed together with the measurement scheme of displacements or, as an option, in the form of a separate outboard unit installed in the recording unit. , the device for remote control via the control unit 13. The electric circuit of the divider 12 is filled in the form of an emitter follower, the input of which is connected to points 31 and 32, and the output from the pick-up terminal 35 through the limiting resistor . the torus 36 is connected to potentiometers 37 and 38. The movable contacts of variable resistors are connected to the voltages of the serially connected control coils 14 and 13, and the middle terminal is connected to the emitter load 39,

During operation of the seismic receiver from the output of the dividers, the feedback signal is connected to the coils 14 and 15, and the coil 14 is given a signal with the polarity of positive feedback (POS), and in the coil 15 it is signaled with a negative negative signal. feedback

5) 5 9AA72

(dew) I at this PIC shifts the inertial mass from the zero position by pulling out the plate-modulator 5 from the point of space zero towards the coils 8 and 9 and reduces the bone of the suspension springs 3 of the inert mass 4, which reduces the natural frequency of the injector mass A expands the range of registration towards lower d frequencies, and the OOS, introduced into coil 15, returns the modulator plate 5 to the point of spatial zero, captures it at this point and stabilizes the working position of the iyortic mass 4, J5 PIC signal strength ratio to the OOS signal, the seismic receiver a (inherent frequency and attenuation) determines the inertial mass parameters

In order to simplify the electrical circuit 20 and its settings with the maximum efficiency of the displacement meter (Fig. 3), its output circuit is made in the form of active loads 28 and 29 on RC filters, where the component of the generator carrier frequency is variable. . filtered by capacitors connected in parallel to the resistors, and the constant component allocated to the loads 28 and 29 as a constant voltage, 30 goes to points 31 and 32, the amplitude and polarity of the output voltage depends on the amplitude and direction of movement seismic receiver with respect to inertial mass, 35

In order to eliminate the mutual influences of the control coils 14 and 15 on the output signal of the first-displacement meter, a divider of the output buckle circuit (Fig 4) is connected to the output of the meter (points 31 and 32),

In order to stabilize the output

The signal of the displacement meter in the gap 7 of the core is reduced to a modulator plate made of brass, which, with the optimal size of the air gap 7, compensates for the uneven density of the high-frequency field between the core of the core, nytcM reducing the inductance of the winding 8 or 9 to which he approaches with,.,.

In order to control the amplitude of the output signal, the slider moves -: - Research institutes without the use of a ballast divider; a slot-modulator made of ferrite is inserted into the core gap, which increases the inductance of the winding to which it approaches, the output amplitude The signal varies in proportion to the voltage of the power supply,.

Claims (1)

 1. A seismic receiver, comprising a housing with an electrodynamic transducer with an inertial mass in the form of a coil placed in it, by means of a diamagnetic body connected to a displacement meter electrically connected to the control unit and the power supply. The fact that, with an extension circuit of the frequency range for recording seismic vibrations and the natural frequency of the seismic receiver towards the ultra-low frequencies, the coil of the electrodynamic converter is additionally equipped with control windings , Displacement meter configured in the form of an inductive transducer with an air gap and comprises plastinu- modulator zakreopennuyu diamagnetic on said rod and putting into voedushny gap with PE-forming ztom output via an electronic control unit connected with the control windings elektrodinakicheskogo gfe--forming, 2, A seismic receiver according to claim 1, 1, and t, which is characterized in that the inductive converter is made in the form of a ferrite ring with a notch, on the ends of which coaxially connected contours of the high-frequency generator are coaxially mounted, and the output circuit of the inductive converter is made in the form active loads on JS-ltrah, with this, the middle points of connection of the specified loads and loop windings of the high-frequency generator are connected to the power source, Fie.2 fig.Z FIG.