INVENTION
Patent of the Russian Federation RU2123816
VIRTUAL METALLIST

VIRRETWEIGHT METAL. KNOW HOW. INTRODUCTION. PATENT. TECHNOLOGIES.

INVENTION. VIRRETWEIGHT METAL. Patent of the Russian Federation RU2123816

Applicant's name: Institute of Metal Physics, Ural Branch of RAS
The name of the inventor: Pudov Vladimir Ivanovich ; Reutov Yuri Yakovlevich; Korotkikh Sergey Alexandrovich
The name of the patent holder: Pudov Vladimir Ivanovich ; Reutov Yuri Yakovlevich; Korotkikh Sergey Alexandrovich
Address for correspondence:
Date of commencement of the patent: 1996.09.18

The device is intended for localization of metallic foreign objects in tissues and organs of man for border localization of foreign objects and can be used in medicine (general surgery and eye surgery), and can be used for nondestructive quality control of materials in other areas.

The eddy current detector contains an alternating current generator, induction sensors with magnetizing and receiving coils, voltage compensators induced in the receiving coils by fields of magnetizing coils, amplifiers of alternating voltage, synchronous detectors of the in-phase and quadrature components, first and second constant-voltage filters, full-wave rectifiers, , The first and second phase shifter, the switch, the pointer indicator, the frequency generator, voltage controlled, the sound indicator. The device allows to increase the accuracy and reliability of the localization of the object, which contributes to an increase in the effectiveness of the use of eddy current detectors, reducing operational traumatism.

DESCRIPTION OF THE INVENTION

The invention relates to search techniques, in particular to medicine (general surgery and eye surgery) for the localization of metallic foreign objects in human tissues and organs, for boundary localization of foreign objects, and can be used for non-destructive quality control of materials in other areas.

The problem of localization and removal of metallic foreign objects (bodies) lying in tissues and organs of a person is difficult and not solved in the practice of operative surgery, which causes unsuccessful operations, severe postoperative complications.

The outcome of such operations largely depends on the accuracy of the location of a metallic foreign object.

Traditional methods of refining diagnostics used for these purposes (X-ray, ultrasound, etc.) are ineffective and lead to excessively unreasonable operational traumatism.

One of the promising technical means used for these purposes in surgery are eddy current induction metal detectors , the operation principle of which is based on the action on the metallic foreign object of an alternating or pulsed magnetic field produced by the magnetizing coil of a metal detector detector . The magnetic field of reradiation of this object is perceived by the receiving coil of the sensor and causes in it the EMF, which is amplified by the electronic unit and fixed by an arrow or other indicator.

Eddy-current metal detectors allow for low-traumatic operations.

However, from all types of introduction of a metallic foreign object into tissues or human organs, the boundary introduction of a foreign object is one of the most difficult in terms of the possibility of its removal. Such operations require high qualification of the surgeon and an unusual tactical approach.

With such operations, the effectiveness of using induction metal detectors used in medicine is limited.

The eddy-current metal detector proposed in the claimed invention solves the task and allows to carry out low-traumatic operations for conventional and boundary localization of a metallic foreign object in human tissues and organs.

The technical application of an induction device intended for changing the magnetic permeability and conductivity of soils and rocks is known [1].

It contains an alternating current generator, an induction sensor with a magnetizing and receiving coil, a voltage compensator induced in the receiving coil by a magnetized coil field, an alternating voltage amplifier, an amplitude detector, a first switch indicator, synchronous detectors of the in-phase and quadrature signal components, first and second DC filters , Arrow indicators in-phase and quadrature signal components, first and second phase shifter.

METAL DESIGNER WORKS AS FOLLOWING

The alternating current produced by the generator, flowing through the magnetizing coil of the sensor, causes around it an alternating magnetic field. In the absence of metal objects near the sensor, the alternating field of the magnetizing coil induces an alternating voltage in the receiving coil of the sensor, which is compensated with some accuracy by the compensator connected by the input to the output of the alternator. As a result, an AC unbalance voltage is present at the input of the AC amplifier due to the non-ideal adjustment of the compensator. From the amplifier output, this unbalance voltage is rectified by the amplitude detector, and the first pointer indicator shows the magnitude of the unbalance voltage module. In addition, the voltage is applied to the signal inputs of the synchronous detectors corresponding to the in-phase and quadrature components controlled through the phase shifters by the voltage from the output of the alternator. As a result of synchronous detection, constant voltages proportional to the in-phase and quadrature components of the unbalance voltage are present at the detector outputs. These constant voltages are cut off by the DC filters and are not passed to the arrow indicators, which result in zero readings.

When the induction pickup is brought to the metal object, an alternating voltage arises in its receiving coil due to the reradiation field of the metal object. This voltage, amplified by the amplifier, is rectified by the amplitude detector and changes the deviation of the first dial gauge. In addition, this voltage is rectified by synchronous detectors, and the rectified voltages pass unhindered through the filters of the DC component, causing deviations of the arrow indicators proportional to the in-phase and quadrature components of the re-emission field of the metal object, respectively.

The device can detect both ferromagnetic and non-ferromagnetic metal objects, and objects consisting of a combination of ferromagnetic and non-ferrous metals.

However, the device has the disadvantage of having to scan the surveyed surface at the same time as the two indicator indicators, which increases the fatigue of the operator, who also has to ensure that no part of the surveyed surface is missed. As a result, a decrease in the reliability and reliability of control.

The closest in terms of technical nature to the claimed device is a device intended for localization of metal objects [2].

The device comprises an alternating current generator, an induction sensor with a magnetizing and receiving coil, a voltage compensator induced in the receiving coil by a magnetizing coil field, an alternating voltage amplifier, synchronous in-phase and quadrature components detectors, a first and second DC filters, a full-wave rectifier, First and second arrow indicators, first and second phase shifter.

METAL DESIGNER WORKS AS FOLLOWING

The alternating current of the generator, flowing through the magnetizing coil of the induction sensor, creates around it an alternating magnetic field. In the absence of metal objects to be detected near the sensor, the alternating field of the magnetizing coil of the sensor induces in its receiving coil an alternating EMF that is compensated with some accuracy by the compensator. The unbalance voltage from the output of the induction sensor is amplified by an AC voltage amplifier. The amplified alternating unbalance voltage is detected by the synchronous detectors of the in-phase and quadrature components, controlled through the phase shifter by the generator voltage. As a result of detection at the detector outputs, constant voltages proportional to the in-phase and quadrature components of the unbalance voltage are obtained. These voltages are not passed by filters of a constant component and therefore at the input of a full-wave rectifier, on one of the inputs of the analogue voltage collector and on the second switch indicator, the voltages are zero. Equal to zero, and the voltage at the output of the full-wave rectifier, and consequently, on the other input of the analog adder, as a result of which the voltage at the first dial gauge is zero.

When the induction pickup is brought to the metal object, it is magnetized by the alternating field of the magnetizing coil and its reradiation field induces an alternating signal voltage in the receiving coil of the sensor. This voltage is not compensated by the compensator and amplified by the amplifier is applied to the signal inputs of the synchronous detectors. As a result of synchronous detection, constant voltages appear proportional to the in-phase and quadrature components of the signal from the metal object at the outputs of the synchronous detectors.

At the outputs of these synchronous detectors there are also constant unbalance voltages, which are summed with the signal voltages. The DC filters cut off these unbalance voltages, and only the voltages of the useful signal appear on the outputs of these filters, with a constant voltage proportional to the in-phase component of the signal appears at the output of the first filter, and a constant voltage proportional to the quadrature component of the signal appears at the output of the second filter. Depending on whether the metal object is ferromagnetic or not, the voltage of the in-phase component at the output of the first filter of the DC component is positive or negative, which is indicated by the second arrow indicator, the deviation of which in one direction from zero indicates that the object is ferromagnetic, and in the other direction - That it is nonferromagnetic.

The voltage at the output of the second filter of the constant component always has one polarity, for example, positive. This is due to the fact that the quadrature component of the signal reflects the losses on the magnetization reversal of the metal object, which can not be less than zero. The full-wave rectifier ensures the voltage of the same polarity (for example, positive) on one of the inputs of the analog adder, regardless of the polarity of the voltage at the output of the first filter of the constant component. On the other input of the adder connected to the output of the second DC filter, the voltage can only be positive. The voltage from the output of the adder causes the deviation of the first dial gauge, proportional to the sum of the absolute value of the in-phase component and the quadrature component of the signal. Thus, the operator, observing the readings of the first dial gauge, learns that the metal object is localized, since the readings of the first dial gauge are oriented to the signal obtained in the search mode of any metal object, i.e. Regardless of whether it is made of a ferromagnetic or non-ferromagnetic metal, and from the readings of the second dial gauge it recognizes the appearance of this metal object, i.e. Ferromagnetic or non-ferromagnetic.

However, this known prototype device has drawbacks that reduce the effectiveness of its use, namely:

  1. The device is not universal enough, since in some cases the localization of metallic foreign objects is difficult due to an induction sensor that allows the most accurate localization of the metal object when the receiving sensor coil senses only the longitudinal component of the reradiation field of the metal object.

  2. The absence of an additional convenient means of controlling the reliability of the localization of a metallic foreign object, which allows, without distracting the surgeon from scanning the surface of the exposed tissues and human organs, to inform him about the localization of metallic foreign objects, which is especially important when a metallic foreign object is located in vital parts of the human body.

The task to solve the claimed invention is the creation of a universal device for determining the location of a metallic foreign object in human tissues and organs, and also at its boundary localization, while increasing the accuracy and reliability of the localization of the object and the effectiveness of eddy-current metal detectors, and reducing operational traumatism.

The task is achieved due to a technical result that can be obtained by the implementation of the invention, namely the expansion of the functional and technical capabilities of eddy current detectors by means of an additional electronic channel with a sensor for the boundary localization of metal objects, increasing the accuracy and reliability of the location of objects due to the sensor design and Additional control with the help of sound indication.

The technical result is achieved due to the fact that a known metal detector containing an alternating current generator, an induction sensor with a magnetizing and receiving coil, a voltage compensator induced in the receiving coil by a magnetizing coil field, an alternating voltage amplifier, synchronous in-phase and quadrature components, first and second filters The constant half-wave rectifier, the analog voltage accumulator, the two phase shifter and the indicator indicator, further comprises an induction sensor with a magnetizing and receiving coil, a voltage compensator induced in the receiving coil by a magnetizing coil field, an alternating voltage amplifier, synchronous in-phase and quadrature components, A second half-wave rectifier, an analogue voltage collector, two phase shifter, a switch, a voltage generator, and a sound indicator, the magnetizing coil of the additional induction sensor being connected to the output of the alternator, and the inputs of both phase shifters and a compensator The output of the voltage compensator is connected to the inductive sensor, the input of the ac voltage amplifier is connected to the receiving coil of the induction sensor, and its output to the signal coils, the control inputs of which are connected to the outputs of the phase shifters, the output of the synchronous detector of the in-phase component is connected to the input of the first filter of the constant component, and The output of the synchronous detector of the quadrature component is connected to the input of the second DC filter, the output of the first DC filter is connected to the input of the full-wave rectifier, and its output to one of the inputs of the analog voltage collector, the other input of the analog voltage accumulator is connected to the output of the second DC filter; The output of the analog adder is connected to one of the switch inputs and the other input of this switch is connected to the output of the first DC filter, one of the inputs of the same switch being connected to the output of the analog voltage adder of the first channel, and the other input of the same switch is connected to the output of the first switch Filter of the DC component of the first channel, the output of the switch is connected to the indicator and to the input of the frequency-controlled voltage generator, and the output of this generator is connected to a sound indicator.

The essence of the invention is explained by a drawing, which shows a functional block diagram of the proposed eddy current detector.

VIRRETWEIGHT METAL. Patent of the Russian Federation RU2123816

The metal detector contains an alternator 1, inductive sensors 2, 17 with magnetizing and receiving coils, voltage compensators 3, 18, induced in the receiving coils by fields of magnetizing coils, amplifiers of alternating voltage 4,19, synchronous detectors 5 and 6, 20 and 21 in-phase and Quadrature components, first 7, 22 and second 8, 23 filters of constant components, full-wave rectifiers 9, 24, analog voltage summers 10, 25, first 11, 26 and second 12, 27 phase shifters, switch 13, pointer indicator 14, frequency generator 15 , Voltage controlled, audible indicator 16.

The alternator 1 is connected to the magnetizing coils of the inductive sensors 2 and 17, to the voltage compensators 3 and 18 and to the inputs of the first 11 and 26, and the second 12 and 27 phase shifters. The receiving coils of the inductive sensors 2 and 17 are connected to the inputs of the ac voltage amplifiers 4 and 19 whose outputs are connected to the signal inputs of the synchronous detectors 5 and 6, 20 and 21 of the in-phase and quadrature components whose control inputs are connected respectively to the outputs of the first 11 and 26, and Second 12 and 27 phase shifters, and outputs respectively to the inputs of the first 7 and 22, and the second 8 and 23 filters of the constant components. The outputs of the first DC filters 7 and 22 are connected to the inputs of the full-wave rectifiers 9 and 24 and the inputs of the switch 13. One of the inputs of the analog voltage summers 10 and 25 is connected to the outputs of the full-wave rectifiers 9 and 24, the others are connected to the outputs of the second filters 8 and 23 of the constants And the outputs of the analog summators of voltages 10 and 25 are connected to the inputs of the switch 13, its output is connected to the switch indicator 14 and to the input of the frequency generator 15 - voltage controlled. The output of the frequency generator 15 is connected to a sound indicator 16.

A comparative analysis of the claimed eddy-current metal detector with a prototype shows that the claimed metal detector is characterized by the presence of a new electronic channel, a new design of an induction sensor (for boundary localization of metallic foreign objects), new connections and elements, namely, that in addition contains an induction sensor with a magnetizing and receiving coils The compensator of the voltage induced in the receiving coil by the field of the magnetized coil, the alternating voltage amplifier, the synchronous detectors of the in-phase and quadrature components, the first and second DC filters, the full-wave rectifier, the analogue voltage accumulator, the first and second phase shifters, the switch, the frequency generator - Sound indicator.

Thus, the claimed metal detector meets the criterion of the invention "novelty".

In order to determine the conformity of the claimed invention to the criterion of "inventive level", let us consider the popularity of its distinctive features that are functionally independent.

When analyzing patent and scientific and technical literature with the aim of studying the state of the art in this field, it has been established that the additional supply of a metal detector with an electronic channel, for the boundary localization of metallic foreign objects, in such metal detectors is unknown.

There is a known metal detector for use in medicine ( Litvinenko AA, Pudov VI, Leman VP "Eddy Current Detector of Foreign Bodies", Medical Technology, N 1, 1992, p.42-43 or AS USSR N 1827197, BI N 26, 1993, p.8, IPC A 61 B 17/50 ).

However, a comparative analysis of this metal detector shows that because of the drawbacks inherent in this well-known metal detector, it does not solve the problem posed. This is due to the following circumstances:

  1. The sensitivity of the metal detector is 1.5 times lower than even the prototype.

  2. The design of the induction sensor is designed to perceive only the longitudinal component of the reradiation field of a metallic object.

  3. Absence of additional (control) indication of the authenticity of the localization of a metallic foreign object.

Thus, the known technical solutions do not provide a complete solution to the problem associated with the expansion of the functional and technical capabilities of eddy current detectors in the localization of metallic foreign objects in the human body.

The proposed technical solution (which is distinguished by the additional supply of a metal detector with a channel for the boundary localization of metallic foreign objects with distinctive working connections, characteristics and output parameters of the signal, realized in the claimed metal detector, is currently unknown in the scientific and technical literature and should not be explicitly explained in the state of the art. New distinctive features inform the object of new, unobvious properties, namely the creation of a universal eddy current location of a metallic foreign object in human tissues and organs, and at its boundary localization, while improving the accuracy and reliability of the localization of the object, and the effectiveness of the use of eddy current detectors, All this allows us to conclude that the claimed object complies with the "inventive step" criterion.

VIRTUAL METAL DESIGNER WORKS AS FOLLOWING

It is installed by means of the switch 13, for example, on the first channel, into the search mode of any metal object.

The alternating current of the generator 1, flowing through the magnetizing coils of the induction sensors 2 and 17, creates around them an alternating magnetic field. In the absence of near the working ends of the sensors of metal objects to be detected, the variable fields of the magnetizing coils of sensors 2 and 17 induce in their receiving coils variable EMF, which are compensated with some accuracy by compensators 3 and 18. Unbalance voltages from the outputs of inductive sensors 2 and 17 amplify in their Channels with amplifiers 4 and 19 variable voltages. The amplified unbalance voltage variables are detected by the synchronous detectors 5 and 6, 20 and 21 of the in-phase and quadrature components controlled via the phase shifters 11 and 12, 26 and 27 by the voltage of the generator 1. As a result of detection, constant voltages are obtained at the outputs of the detectors 5 and 6, 20 and 21, Proportional to the in-phase and quadrature components of the unbalance voltage in their channels, respectively. These voltages are not passed by filters 7 and 8, 22 and 23 of the constant components, and therefore both on the inputs and outputs of the full-wave rectifiers 9 and 24, and on the analog voltage summers 10 and 25, and on the switch 14 and the sound 16 voltage indicators are zero. Consequently, the stresses are zero even in cases where the metal detector operates in the mode of determining the type of metal, and in the case of its operation on the second channel.

When the sensor 2 of the first channel is brought to the metal object, it is magnetized by the alternating field of the magnetized coil.

The receiving coil of the sensor 2 senses the longitudinal component of the intrinsic reradiation field of the metal object, as a result of which the variable EMF induced in the receiving coil of the sensor 2 is not compensated by the compensator 3 and this voltage amplified by the amplifier 4 is applied to the signal inputs of the synchronous detectors 5 and 6. In As a result of synchronous detection, constant voltages appear proportional to the in-phase and quadrature components of the signal from the metal object at the outputs of synchronous detectors 5 and 6.

At the outputs of these synchronous detectors 5 and 6 there is also a constant unbalance voltage, which is summed with the signal voltages. The DC filters 7 and 8 cut off these unbalance voltages, and only the useful signal voltages appear at the outputs of these filters, with a constant voltage proportional to the in-phase component of the signal appearing at the output of the first filter 7, and proportional to the quadrature component of the signal at the output of the second filter. Depending on whether the metal object is ferromagnetic or not, the voltage of the in-phase component at the output of the first filter 7 of the constant component is positive or negative, which is indicated when the metal detector is switched to the mode of operation for determining the type of metal, arrow and sound indicators. Отклонение стрелочного индикатора в одну сторону от нуля показывает, что предмет ферромагнитный, а в другую сторону - что он неферромагнитный. Звуковая индикация указывает только на один вид металла - ферромагнитный или неферромагнитный.

Напряжение на выходе второго фильтра 8 постоянной составляющей всегда имеет одну полярность, например, положительную. Обусловлено это тем, что квадратурная компонента сигнала отражает потери на перемагничивании металлического предмета, которые не могут быть меньше нуля. Двухполупериодный выпрямитель 9 обеспечивает появление на одном из входов аналогового сумматора напряжений 10 напряжение одной и той же полярности (например, положительный), независимо от полярности напряжения на выходе первого фильтра 7 постоянной составляющей. На другом входе сумматора 10, подключенном к входу второго фильтра постоянной составляющей, напряжение может быть только положительным. Напряжение с выхода сумматора 10, подключенного к одному из входов переключателя 13, установленного в режим поиска любого металлического предмета, вызывает отклонение стрелочного индикатора 14, пропорциональное сумме абсолютного значения синфазной компоненты и квадратурой компоненты сигнала, при этом это напряжение и поступает на вход генератора частоты 15 - управляемого напряжением, а с его выхода на звуковой индикатор 16.

При переключении металлоискателя на второй канал в режим поиска любого металлического предмета и при поднесении датчика 17 второго канала к металлическому предмету, он намагничивается переменным полем намагничивающей катушки. Приемная катушка датчика 17 воспринимает поперечную компоненту собственного поля переизлучения металлического предмета, в результате этого переменная ЭДС, наводимая в приемной катушке датчика 17, не компенсируется компенсатором 18, и это напряжение, усиленное усилителем 19, подается на сигнальные входы синхронных детекторов 20 и 21. В результате синхронного детектирования на выходах синхронных детекторов 20 и 21 появляются постоянные напряжения, пропорциональные соответственно синфазной и квадратурной компонентам сигнала от металлического предмета.

На выходах этих синхронных детекторов 20 и 21 присутствуют и постоянные напряжения небаланса, которое суммируется с напряжениями сигнала. Фильтры 22 и 23 постоянной составляющей отсекают эти напряжения небаланса, и на выходах этих фильтров появляются только напряжения полезного сигнала, причем на выходе первого фильтра 22 появляется постоянное напряжение, пропорциональное синфазной компоненте сигнала, а на выходе второго фильтра 23 - пропорциональные квадратурной компоненте сигнала. В зависимости от того, является металлический предмет ферромагнитным или нет, напряжение синфазной компоненты на выходе первого фильтра 22 постоянной составляющей положительно или отрицательно, что и индицируется при переключении металлоискателя в режим работы определения вида металла, стрелочным и звуковым индикаторами. Отклонение стрелочного индикатора в одну сторону от нуля показывает, что предмет ферромагнитный, а в другую сторону - что он неферромагнитный. Звуковая индикация указывает только на один вид металла - ферромагнитный или неферромагнитный.

Напряжение на выходе второго фильтра 23 постоянной составляющей, как и на первом канале всегда имеет одну полярность, например, положительную.

Двухполупериодный выпрямитель 24 обеспечивает появление на одном из выходов аналогового сумматора напряжений 25 напряжения одной и той же полярности (например, положительной), независимо от полярности напряжения на выходе первого фильтра 22 постоянной составляющей. На другом входе сумматора 10, подключенном к входу второго фильтра 23 постоянной составляющей, напряжение может быть только положительным. Напряжение с выхода сумматора 10, подключенного к одному из входов переключателя 13, установленного в режим поиска любого металлического предмета, вызывает отклонение стрелочного индикатора 14, пропорциональное сумме абсолютного значения синфазной компоненты и квадратурной компоненты сигнала. При этом это напряжение и поступает на вход генератора частоты 15 - управляемого напряжением, а с его выхода на звуковой индикатор 16.

Таким образом, при работе металлоискателя на любом канале в режиме поиска металлического предмета, оператор, наблюдая за показаниями стрелочного индикатора и с помощью звукового индикатора, узнает о локализации металлического инородного предмета, а в режиме определения вида металла - о его нефферомагнитности или ферромагнитности.

Предлагаемый в заявляемом изобретении вихретоковый металлоискатель, благодаря своей универсальности, позволяет определить местоположение металлических инородных предметов в тканях и органах человека, а и при их пограничной локализации, за счет расширения своих функциональных и технических возможностей при одновременном повышении точности и достоверности локализации металлических предметов, за счет конструкции индукционного датчика и дополнительного контроля с помощью звуковой индикации. Все это ведет к снижению операционной травматичности и повышению эффективности применения вихретоковых металлоискателей.

INFORMATION SOURCES

  1. Будько Г.С. Прибор для измерения магнитной проницаемости и проводимости грунтов и горных пород. Труды Сибирского физико-технического института при Томском госуниверситете. Issue. 61. -Томск: изд. Томского университета, 1976, с. 164-173.

  2. Патент РФ N 2046377, G 01 V 3/10, 1995.

CLAIM

An eddy current detector with an alternating current generator, an induction sensor with a magnetizing and receiving coil, a voltage compensator induced in the receiving coil by a magnetizing coil field, an alternating voltage amplifier, synchronous in-phase and quadrature components, a first and second DC filters, a full-wave rectifier, Voltages, two phase shifter and switch indicator, the output of the alternator is connected to the magnetizing coil of the induction sensor, and both to the inputs of both phase shifters and the voltage compensator, the output of the voltage compensator is connected to the inductive sensor, the input of the AC amplifier to the receiving coil of the induction sensor, and Its output to the signal inputs of synchronous detectors in-phase and quadrature components whose control inputs are connected to the outputs of the phase shifters, the output of the synchronous detector of the in-phase component is connected to the input of the first filter of the constant component, and the output of the synchronous detector of the quadrature component to the input of the second filter of the constant component, Of the DC filter is connected to the input of a full-wave rectifier and the output of this rectifier to one of the inputs of the analog voltage adder, the other input of which is connected to the output of the second DC filter, characterized in that it further comprises an induction sensor with a magnetizing and receiving coil, The amplifier of an alternating voltage, synchronous detectors of an in-phase and quadrature component, the first and second filters of a constant component, a full-wave rectifier, an analogue voltage accumulator, two phase shifter, a switch, a frequency generator controlled by a voltage, and a sound indicator, The coil of the additional induction sensor is connected to the output of the alternator, and both the phase shifters and the voltage compensator are connected to its output, the output of the voltage compensator is connected to the inductive sensor, the input of the ac voltage amplifier to the receiving coil of the induction sensor, and its output to the signal inputs Synchronous detectors of the in-phase and quadrature components whose control inputs are connected to the output of the phase shifter, the output of the synchronous detector of the in-phase component is connected to the input of the first DC filter, and the output of the synchronous quadrature component detector is to the input of the second DC filter; the output of the first DC filter is connected to the input Full-wave rectifier, and its output to one of the inputs of the analog voltage collector, the other input of which is connected to the output of the second DC filter, and the output of the analog adder is connected to one of the inputs of the switch whose other input is connected to the output of the first DC filter, One of the inputs of the same switch is connected to the output of the analogue voltage collector of the first channel, another input to the output of the first filter of the constant component of the first channel, the output of the switch is connected to the indicator and to the input of the frequency generator controlled by voltage, and the generator output is connected to a sound indicator.

print version
Date of publication 12.11.2006гг