RU2153682C1 - Ferroprobe magnetometer - Google Patents

Abstract

FIELD: magnetic measurements, in particular, ferroprobe portable magnetometers. SUBSTANCE: the ferroprobe magnetometer has three ferroprobes with mutually orthogonal magnetic axes and series-connected output windings and excitation windings connected to the respective outputs of the switched excitation unit, series-connected amplifier/converter unit connected to the output winding of the first ferroprobe, the first threshold device and an OR gate, series-connected integrator, whose control input is connected to the output of the OR gate, and the third one - to the inverter output, and the second threshold device, recording unit, control unit generator, whose first, second and third outputs are connected respectively to the control input of the amplifier/converter unit, frequency input of the switched excitation unit and control (sync) input of the control unit, whose first through fourth outputs are connected respectively to the first through fourth control inputs of the switched excitation unit, integrating unit with linear and quadratic outputs, whose frequency input is connected to the fourth output of the generator, the first linear output is connected to the second input of the first threshold device and to the integrator input, the second one - to the data input of the recording unit, the quadratic output is connected to the second input of the second threshold device, and the first and second control inputs - respectively to the fifth and fourth outputs of the control unit, the first and fifth ones via the inverter, whose outputs are connected respectively to the inputs of the AND gate, whose output is connected to the integrator nullification input, operating condition setting unit and logical device, whose first input is connected to the output of the second threshold device, the eleventh, eighth, fifth and second inputs are connected respectively to the first through fourth outputs of the control unit, the twelfth, tenth, sixth and third inputs are connected respectively to the first through fourth outputs of the operating condition setting unit, the fourth, seventh and tenth inputs are connected to the output of the first threshold device, and the output is connected to the control input of the recording unit. The given device measures the component and modulus of the vector of magnetic field induction with the aid of the measuring channel operating in the multiplex mode produced by successive change-over of currents to the excitation windings of the ferroprobes. EFFECT: reduced cost, power consumption and widened functional abilities make it possible to use the given device for designing of self-contained magnetometers used in navigational, geophysical and exploratory equipment. 4 dwg

Description

 The invention relates to the field of magnetic measurements, in particular to portable magnetic measuring instruments for measuring the components and the full induction vector of the Earth's magnetic field.

A device for measuring the magnetic induction vector (A.S. N 760002 according to the application N 2625147 / 18-21 from 08.06.78, M. Cl ³ G 01 R 33/02), containing component magnetometers with orthogonally oriented magnetic probes, a digital integrator with linear and quadratic outputs, adder, code converter - voltage, recording device, clock, voltage comparators according to the number of component magnetometers, code comparison unit and registers.

 In this device, in the process of comparing the output voltages of component magnetometers with a linearly variable voltage of the code-voltage converter connected to the linear output of a digital integrator, the values of the measured components and the module of the magnetic field induction vector are formed.

 The disadvantage of this device is the complexity, requiring large hardware costs, and high power consumption, due to the simultaneous consumption of all three component magnetometers and a complex electronic device.

There is also known a device for measuring the module of the vector of magnetic induction (A. C. N 789944 according to the application N 2726724 / 18-21 from 02.19.79, M. Кл ³ G 01 R 33/02), containing component magnetometers with orthogonally oriented magnetic probes, serially connected clock generator and integrating unit with linear and quadratic outputs, voltage comparators connected to the outputs of component magnetometers and linear output of the integrating unit, memory elements whose inputs are connected to the quadratic output of the integrating unit, input control s - to the outputs of the first three voltage comparators, and the outputs through an analog adder are connected to the fourth voltage comparator, the second input of which is connected to the quadratic output of the integrating unit, and the output - to the register control input, the information input of which is connected to the linear output of the integrating unit, moreover, the integrating unit contains a series-connected pulse counter connected to the output of the generator, and the first digital-to-analog converter (DAC), the second DAC (multiply one), the analog input of which is connected to the output of the first DAC, and the digital inputs are connected to the outputs of the pulse counter, which are the first linear (digital) output, the output of the first DAC is the second linear (analog) output, and the output of the second DAC is the quadratic (analog) output integrating unit.

 The device operates as follows.

 As a result of counting the output pulses of the generator in the integrating unit, linearly increasing and quadratic signals are formed, cyclically repeated during the operation of the device. At the moments when the output voltages of the component magnetometers are equal to the linearly increasing voltage of the integrating unit, the square of the instantaneous voltage value in the corresponding memory element is stored by the comparator signals, then these values are summed in the analog adder and compared in the additional comparator with the quadratically increasing voltage of the integrating unit. At the moment of equality of these voltages, according to the signal of an additional comparator, the value of the code generated at the output of the counter of the integrating unit is recorded in the recording unit. This value is equal to the square root of the sum of the squares of the three orthogonal components (components) of the magnetic induction vector, i.e., the module of the magnetic induction vector. In the recording unit, the magnetic induction vector module is registered.

 The use of the indicated structure of the integrating unit in this device allows a noticeable simplification of the circuit compared to the previous analogue.

 The disadvantages of this device are the large hardware costs due to the number of measuring channels of the magnetometer, and the high power consumption caused by the simultaneous consumption of currents in the excitation circuits of the flux gates.

The closest in technical essence to the proposed one and selected as a prototype is a flux-gate magnetometer (AS N 1755219, MKI ⁵ G 01 R 33/02 according to the application N 4/28238/21 from 03/21/90. Flux-gate magnetometer), containing three a flux-gate with mutually orthogonal magnetic axes, each consisting of a core, an excitation winding connected to the corresponding outputs of a switched excitation block and an output winding, an amplification-conversion block, the input and output of which feedback are connected to the input terminal of the output winding the first flux gate, the output terminal of which is connected to the input terminal of the output winding of the second flux gate, the output terminal of which is connected to the input terminal of the output winding of the third flux, the output terminal of which is connected to a common wire, a recording unit, a control unit and a generator, the first output of which is connected to the control input amplifier-conversion unit, the second with the frequency input of the switched excitation unit, and the third with the control (synchronization) input of the control unit, from the first to the third outputs the board of which is connected respectively to the first to third inputs of the control of the switched excitation unit, and the output of the signal indicating the end of the transient process is connected to the control input of the recording unit, the information input of which is connected to the output of the amplifier-converter unit.

 The device operates as follows.

 The generator generates a voltage at the second output at a frequency equal to the excitation frequency of the flux gates, which, through the switched excitation block, enters alternately into the excitation windings of the corresponding flux gates. The switching of the field windings and the generation of field signals are carried out by a switched field unit controlled by the control unit. The sequence of excitation of flux gates is determined by the sequence of occurrence of signals at the corresponding outputs of the control unit.

 The measured magnetic field induction, acting simultaneously on three flux gates, causes the voltage of the useful signal of the second harmonic to appear on the output winding of the flux gate whose voltage is applied to the excitation winding. Since the output windings of the flux gates are connected in series, the voltage of the useful signal of the second harmonic, the amplitude of which is determined by the component of the magnetic field induction vector measured by the corresponding flux gate, is currently being input to the amplifier-converter block. In the amplifier-converter unit, the voltage is amplified by alternating current, detected, amplified by direct current, and then fed to the output of the amplifier-converter unit and feedback output, creating a feedback current in the output windings of the flux gates. From the output of the amplifier-converter unit, a voltage proportional to the corresponding component of the magnetic field induction vector enters the recording unit. Using feedback, a magnetic field is created in the currently excited flux gate, which compensates for the corresponding component of the measured magnetic field.

 The phase-sensitive demodulator of the amplifier-converter unit is controlled by voltage pulses supplied from the first output of the generator to the control input of the amplifier-converter unit, and using the voltage pulses supplied from the third output of the generator to the control input of the control unit, the operation of the last and switched excitation unit is synchronized.

 After the end of the transient process caused by the switching of the field windings and the action of an external field on the flux gates, the recording unit, by the output signal (sign of the end of the transient process) of the control unit, fixes steady-state voltage values at the output of the amplifier-transducer unit, proportional to the corresponding components of the measured field.

 The multiplex mode of operation of the measuring channel and excitation circuits of the flux gates provides simplicity of the circuit implementation of the device and low power consumption.

 The disadvantage of this device is the low functionality due to the lack of measurement of the module of the magnetic field induction vector, as well as the lack of the ability to generate digital codes of the components of the magnetic field induction vector.

 The technical result achieved by using the proposed technical solution is to expand the functionality of the flux-gate magnetometer, i.e. ensuring the execution of the operation of generating digital codes of the module and components of the magnetic field induction vector at low additional hardware costs.

 This result is achieved by the fact that in a flux-gate magnetometer containing three fluxgates with mutually orthogonal magnetic axes, each consisting of a core, an excitation winding connected to the corresponding outputs of a switched excitation block and an output winding, an amplifier-converter block, its input and feedback output are connected to the input terminal of the output winding of the first flux gate, the output terminal of which is connected to the input terminal of the output winding of the second flux gate, the output terminal of which is connected is connected to the input terminal of the output winding of the third fluxgate, the output terminal of which is connected to a common wire, a recording unit, a control unit, and a generator, the first output of which is connected to the control input of the amplifier-converter unit, the second to the frequency input of the switched excitation unit, and the third to the control input of the control unit, from the first to third control outputs of which are connected respectively to the first to third inputs of the exercise of the switched excitation unit, and also having a signal output As the transition process ends, the first threshold device connected to the output of the amplifier-converter unit is additionally introduced, the output of which is connected to the first input of the OR element, the second input of which is connected to the fourth control output of the control unit and the fourth control input of the switched excitation unit, the integrator connected in series and the second a threshold device integrating a block with linear and quadratic outputs, the frequency input of which is connected to the fourth output of the generator, the first line output is connected to the second input of the first threshold device and to the integrator input, the second (digital) line output is connected to the information input of the recording unit, the quadratic output is connected to the second input of the second threshold device, and the first and second control inputs are connected to the fifth and fourth the outputs of the control unit, the first output of which is connected to the first input of the AND element, and the fifth through an inverter is connected to the third input of the OR element and to the second input of the AND element, the output of which is connected to the input of the integrator to “zero”, the input of the operating mode of which is connected to the output of the OR element, the mode setting unit and a logic device (4I, OR), the first input of which is connected to the output of the second threshold device, the eleventh, eighth, fifth and second inputs connected respectively to the first to fourth outputs of the control unit, the twelfth, ninth, sixth and third inputs are connected respectively to the first to fourth outputs of the mode setting unit, the fourth, seventh and tenth inputs are connected to the output of the first threshold new device, and the output is connected to the control input of the recording unit.

 In FIG. 1 shows a block diagram of a flux-gate magnetometer; FIG. 2 shows timing diagrams of operation, and FIG. 3 and 4, respectively, are structural diagrams of an integrating unit and an integrator.

Fluxgate magnetometer contains three ferroprobe 1, 2, 3 (FZ _x, FZ _y, FZ _z) with mutually orthogonal magnetic axes, each consisting of a core 4, 5, 6, the field winding 7 (W _Bx), 8 (W _wu) 9 (W _bz ) connected to the corresponding outputs of the switched excitation block 16 and the output (measuring) winding 10 (W _x ), 11 (W and _y ), 12 (W and _z ), connected in series to the amplifier-converter block 13, the first threshold device 18 and an OR element 19, wherein the input of the amplifier-converter unit 13 and its feedback output are connected to the input I press the output winding 10 of the first flux gate 1, the output terminal of which is connected to the input terminal of the output winding 11 of the second flux gate 2, the output terminal of which is connected to the input terminal of the output winding 12 of the third flux gate 3, the output terminal of which is connected to a common wire, integrator 20 connected in series, input which is connected to the output of the OR element 19, and the second threshold device 21, the recording unit 14, the control unit 17, the generator 15, the first output of which is connected to the control input of the amplifier-converter Lock 13, the second with the frequency input of the switched excitation block 16, and the third with the control input of the control unit 17, the first to fourth control outputs of which are connected respectively from the first to fourth control inputs of the switched excitation block 16, the integrating block 22 with linear and quadratic outputs, the frequency input of which is connected to the fourth output of the generator 15, the first linear output is connected to the second input of the first threshold device 18 and to the input of the integrator 20, the second digital linear output is connected inen with the information input of the recording unit 14, the quadratic output is connected to the second input of the second threshold device 21, and the first and second control inputs are connected respectively to the fifth and fourth outputs of the control unit 17, the first output of which is connected to the first input of the element And 23, and the fifth through the inverter 26 is connected to the third input of the OR element 19 and to the second input of the And 23 element, the output of which is connected to the zero input of the integrator 20, the input of the operating mode of which is connected to the output of the OR element 19, the task unit 24 mode and logical device 25 (4I, OR), the first input of which is connected to the output of the second threshold device 21, the eleventh, eighth, fifth and second inputs are connected respectively from the first to fourth outputs of the control unit 17, twelfth, ninth, sixth and third inputs connected respectively from the first to fourth outputs of the mode setting unit 24, the fourth, seventh and tenth inputs are connected to the output of the first threshold device 18, and the output is connected to the control input of the recording unit 14.

 The operation of the device is as follows.

The generator 15 generates a voltage U _f at a frequency f _in equal to the excitation frequency of the flux gates 1 - 3, which is supplied to the frequency input of the switched excitation block 16. In the latter, the field windings 7 - 9 of the flux gates 1 - 3 are sequentially switched and pulse generation of the excitation signals by power and form. The switching control of the switched excitation unit 16 is carried out by the control output signals U _C1 , U _C2 , U _C3 , U _C4 of the control unit 17. The excitation sequence of flux gates 1 - 3 is determined by the sequence of occurrence of control signals U _C1 , U _C2 , U _C3 , respectively, on the first, second and third outputs of the control unit 17. When the control signal _C4 U at the fourth output of the control unit 17 via the switched excitation unit carried off applying an excitation voltage to all winding excitaton Denia ferroprobes 7-9 1-3. Thus, the voltage U _fv , passing through the switched excitation block 16, excites flux gates 1, 2, 3, in turn. So, in the time interval (t ₂ - t ₁ ), the flux gage 1 (ФЗ _x ) is excited, in the interval (t ₃ - t ₂ ) - a flux gate 2 (ФЗ _y ), on a segment (t ₄ - t ₃ ) - a flux gate 3 (ФЗ _z ), and on a segment (t ₅ - t ₄ ) the excitation windings 7-9 of all fluxgates 1-3 are disconnected ( de-energized) condition (figure 2).

The measured magnetic field induction, acting simultaneously on three fluxgates 1-3, causes the appearance of a voltage of a useful signal with a frequency of 2f _in the output winding of that fluxgate, the excitation winding of which is currently supplied with an excitation voltage U _fv . Since the output winding ferroprobes 1-3 are connected in series, the input of the amplifying and conversion unit 13 in the interval (t ₂ -t ₁₎ receives the voltage of the second harmonic (frequency 2f _c), whose amplitude is determined by the first component (B _X) of the vector of magnetic induction T , in the interval (t ₃ - t ₂ ) - the second component (B _Y ), in the interval (t ₄ - t ₃ ) - the third component (B _z ), in the interval (t ₅ - t ₄ ) - the absence of a useful signal, t .e. zero value, etc.

поступает на первый вход первого порогового устройства 18. С помощью обратной связи в возбужденном в данный момент феррозонде создается магнитное поле, компенсирующее соответствующую составляющую измеряемого внешнего магнитного поля.In the amplifier-converter unit 13, the voltage is amplified by alternating current, detected, amplified by direct current, and then fed to the main output and feedback output of the amplifier-converter unit 13, creating a feedback current in the output windings 10-12 of flux gates 1-3. From the output of the amplification-converting unit 13, the voltage U ₁₃ is equal to, at the corresponding time intervals, the voltages U _X , U _Y , U _z proportional to the corresponding components B _X , B _Y , B _Z of the induction vector

arrives at the first input of the first threshold device 18. Using feedback in a currently excited flux gate, a magnetic field is created that compensates for the corresponding component of the measured external magnetic field.

 The phase-sensitive demodulator of the amplifier-converter unit 13 is controlled by voltage pulses supplied from the first output of the generator 15 to the control input of the amplifier-converter unit 13, and using the voltage pulses supplied from the third output of the generator 15 to the control input of the control unit 17, the operation of the latter is synchronized and a switched block excitation 16.

After the end of the transition process at time instants t ' ₁ , t' ₂ , ..., t ' _i , (i = 1,2, ..., 4), caused by switching the field windings 7 - 9 and the action of an external field on the flux gates 1 - 3, voltage pulses Ut ' _i appear on the fifth output of the control unit 17 (Fig. 2), which are signals of the sign of the end of the transient process.

As a result of counting the voltage pulses U _fcc in the integrating unit 22, supplied to the input of the last from the fourth output of the generator 15, linearly increasing analog U _l at the first linear output, digital N _l at the second linear output and quadratic analog U _k at the quadratic output are formed integrating unit 22 signals cyclically repeated during operation of the device. Moreover, the formation of linearly increasing signals is carried out in all four repeated cycles and begins after the end of the transition process in the amplifier-converter unit 13, i.e. at the time of the appearance of the signal indicating the end of the transient process Ut ' _i , supplied from the fifth output of the control unit 17 to the first control input of the integrating unit 22. The quadratic signal U _{k is} generated only in every fourth cycle if there is a control signal U _С4 at the second control input of the integrating unit 22 supplied from the fourth control output of the control unit 17, and also starts at the moment of the appearance of the signal Ut ' _{i of the} sign of the end of the transient process (Fig. 2).

Следовательно, обнуление (предварительная подготовка) интегратора 20 осуществляется в первом цикле до окончания переходного процесса в усилительно-преобразовательном блоке 13. При подаче на вход управления интегратора 20 потенциала, соответствующего логическому нулю, формируемого на выходе элемента ИЛИ 19, интегратор 20 находится в режиме интегрирования и, наоборот, при логической единице интегратор находится в режиме хранения. Сигнал управления режимом U₁₉ интегратора 20, формируемый элементом ИЛИ, определяется следующим логическим выражением:
U₁₉ = U₁₈∨U_C4∨U₂₆, (2)
где U₁₈, U₂₆ - выходные сигналы соответственно первого порогового устройства 18 и инвертора 26.The integrator 20 integrates in the first three cycles (i = 1, 2, 3) the output ramp voltage U _{l of the} integrating unit 22, and the integration process begins with preliminary zeroing of the integrator 20 in the first cycle when the output signal U _{23 of the} element And to the installation input in the "0" (UO) of the integrator 20. The formation of the logical potentials of the voltage U _{23 is} carried out by supplying the output signals U _C1 and Ut ' _i of the control unit 17 respectively to the first and through the inverter 26 to the second inputs of the element And, i.e.

Therefore, zeroing (preliminary preparation) of the integrator 20 is carried out in the first cycle until the end of the transition process in the amplifier-converter unit 13. When the integrator 20 is supplied with a potential corresponding to the logical zero generated at the output of the OR element 19, the integrator 20 is in the integration mode and, conversely, with a logical unit, the integrator is in storage mode. The control signal of the mode U _{19 of the} integrator 20, formed by the OR element, is determined by the following logical expression:
U ₁₉ = U ₁₈ ∨U _C4 ∨U ₂₆ , (2)
where U ₁₈ , U ₂₆ are the output signals, respectively, of the first threshold device 18 and inverter 26.

At the moment of equality of the output voltage of the amplifier-converter unit 13 with the output linearly increasing voltage U _{l of the} integrating unit 22, the first threshold device 18 generates a control signal U ₁₈ in the form of a logic unit passing through the OR element 19 to the control output of the integrator 20, which transfers it to the storage mode . Thus, in the first three conversion cycles, the integrator 20 on the interval (t ' ₁ - t ₁ ) is zeroed, on the intervals (t'' ₁ - t' ₁ ), (t '' ₂ - t ' ₂ ), (t'' ₃ - t ' ₃ ) is in integration mode, and in the intervals (t' ₂ - t '' ₁ ), (t ' ₃ - t'' ₂ ) and throughout the fourth cycle (t ₅ - t ₄ ) - in the mode information storage, etc.

In the fourth conversion cycle at the moment of equal output voltage (U ₂₀ ) of the integrator 20 with the output quadratic voltage U _{to the} integrating unit 22, the second threshold device 21 generates a control signal U ₂₁ in the form of a logical unit.

где α - масштаб преобразования интегратора 20, определяемый его постоянной времени. Причем
U_л(t) = кτ, (6)
где к - масштаб преобразования интегрирующего блока 22 на линейном выходе. Причем на интервалах преобразования

С учетом выражения (7) выражение (5) принимает следующий вид:

Проинтегрировав выражение (8), получим

где

Выбрав масштаб преобразования интегрирующего блока 22 по квадратичному выходу равным β, имеем
U_к(t) = β[U_л(t)]². (10)
Тогда в момент срабатывания t''₄ порогового устройства 21 в четвертом цикле преобразования получим следующее равенство:
β[U_л(t)]² = β(U $\genfrac{}{}{0ex}{}{\text{2}}{\text{x}}$ +U $\genfrac{}{}{0ex}{}{\text{2}}{\text{y}}$ +U $\genfrac{}{}{0ex}{}{\text{2}}{\text{z}}$ ). (11)
Следовательно, соответствующий квадратичному значению в момент t''₄ кодовый эквивалент N_л(t''₄) на линейном выходе интегрирующего блока 22, записываемый в регистрирующий блок 14, равен корню квадратному из суммы квадратов компонент, а следовательно, модулю вектора индукции магнитного поля.The device operates in the measurement modes of components B _X , B _Y , B _Z and in the measurement mode of the module T of the magnetic field induction vector. The result of the measurement is the codes N _X , N _Y , N _Z and N _T corresponding to these values. The operation modes are set by the mode setting unit 24, executed, for example, in the form of a keypad or in the form of an automatic signal shaper. So, when setting voltage U _P1 in the form of a logical unit potential at the first output of mode 24 setting unit, component B _X is measured, voltage U _P2 at the second output - component B _Y is measured, voltage U _P3 at the third output - component B _Z and voltage are measured U _P4 at the fourth output is a measurement of the module T of the magnetic field induction vector. In this case, the measurement result (N _X , N _Y , N _Z , N _T ) in the selected mode is recorded in the recording unit 14 by the output signal of the logic device 25. When measuring the components B _X , B _Y , B _{Z, the} output unit is recorded in the recording unit 14 code (N _L = N _X , N _Y , N _Z ) generated on the digital linear output of the integrating unit 22, respectively, at the triggering times t '' ₁ , t '' ₂ , t '' _{3 of the} first threshold device 18. Signals for recording control in the recording unit 14, formed at the output of the logical device 25, is determined by the following expression:
U ₂₅ (t '' _i ) = U _pi (t '' _i ) U _ci (t '' _i ) U ₁₈ (t '' _i ) for i = 1, 2, 3. (3)
When measuring the module T in the recording unit 14, the output code is recorded (N _l = N _t ), which is also generated on the linear output of the integrating unit 22 at the time t '' _{4 of the} second threshold device 21. The control signal is written to the recording unit 14 at the output of the logical device 25 in this case is formed in accordance with the expression
U ₂₅ (t '' ₄ ) = U _p4 (t '' ₄ ) U _c4 (t '' ₄ ) U ₂₁ (t '' ₄ ). (4)
The voltage U ₂₀ stored in the fourth cycle in the integrator 20, accumulated over the previous three conversion cycles, is determined by the following expression:

where α is the transform scale of the integrator 20, determined by its time constant. Moreover
U _l (t) = kτ, (6)
where k is the conversion scale of the integrating unit 22 at the linear output. Moreover, at conversion intervals

In view of expression (7), expression (5) takes the following form:

Integrating expression (8), we obtain

Where

Having chosen the conversion scale of the integrating block 22 by the quadratic output equal to β, we have
U _to (t) = β [U _l (t)] ² . (10)
Then, at the moment t '' _{4 of the} threshold device 21 is triggered, in the fourth conversion cycle we obtain the following equality:
β [U _l (t)] ² = β (U $\genfrac{}{}{0ex}{}{\text{2}}{\text{x}}$ + U $\genfrac{}{}{0ex}{}{\text{2}}{\text{y}}$ + U $\genfrac{}{}{0ex}{}{\text{2}}{\text{z}}$ ) (eleven)
Consequently, the corresponding quadratic value at time t '' ₄ coded equivalent of N _L (t '' ₄₎ on a linear output of the integrating unit 22, a recordable in the recording unit 14 is equal to the square root of the sum of squares of components, and hence the absolute value of the magnetic induction field .

The integrating unit (figure 3) described in the analogue (A.S. N 789944 M. Cl. ³ G 01 R 33/02 according to the application N 2726724 / 18-21 from 02.19.79), contains a pulse counter (Sch), first DAC and second multiplier DAC.

The outputs of the pulse counter and the first DAC are linear, respectively, digital (N _l ) and analog (U _l ) outputs, and the output of the second DAC is a quadratic output (U _to ).

The start of the pulse counter is carried out by the output signal (Ut ' _i ) of the control unit 17, and the second DAC is started by the signal U _c4 supplied from the fourth control output of the control unit 17 to the control input of the second DAC. When the counter reaches the maximum value of the code at the time of the arrival of the next counting pulse U _fcc , it is reset to zero due to overflow and the entire operation cycle is repeated again.

A possible and widely known embodiment of the integrator 20 (Fig. 4) contains an analog integrating operational amplifier (op amp) with a resistor R and a capacitor C. Using the managed switches P1 and P2, the integrator 20 is integrated, stored and zeroed. The integrator is reset to zero. closing the key K of the switch P2 control signal U ₂₃ . In the integration mode of the voltage U _{l, the} keys K1 and K2 of the switch P1 controlled by the voltage U ₁₉ are respectively in the closed and open positions, and the key K of the switch P2 is in the open position. In the information storage mode, on the contrary, the keys K1 and K2 of the switch P1 are respectively in the open and closed positions, also when the key K of the switch P2 is open.

 Thus, the proposed device, combining the positive qualities of analogues and a prototype, is realizable, has wide functional capabilities and low power consumption at low hardware costs and, therefore, can be used in the construction of a portable magnetic measuring device or structurally functional module in the form of a microcircuit.

Claims (1)

A fluxgate magnetometer containing three fluxgates with mutually orthogonal magnetic axes, each consisting of a core, an excitation winding connected to the corresponding outputs of a switched excitation block and an output winding, an amplifier-converter block, the input and output of which is connected to the input terminal of the output winding of the first flux probe the output terminal of which is connected to the input terminal of the output winding of the second flux gate, the output terminal of which is connected to the input terminal of the output winding a third flux-gate, the output clamp of which is connected to a common wire, a recording unit, a control unit, and a generator, the first output of which is connected to the control input of the amplification-conversion unit, the second to the frequency input of the switched excitation unit, and the third to the control input of the control unit, s the first to third control outputs of which are connected respectively to the first to third control inputs of the switched excitation unit, characterized in that it is additionally connected to the output connected to the output of the amplifier-converter unit, the first threshold device, the output of which is connected to the first input of the OR element, the second input of which is connected to the fourth control output of the control unit and the fourth control input of the switched excitation unit, an integrator and a second threshold device that integrates the unit with linear and quadratic outputs ,
whose frequency input is connected to the fourth output of the generator, the first linear output is connected to the second input of the first threshold device and the integrator input, the second linear output is to the information input of the recording unit, the quadratic output is to the second input of the second threshold device, and the first and second control inputs are connected respectively, with the fifth and fourth outputs of the control unit, the first output of which is connected to the first input of the AND element, and the fifth through an inverter is connected to the third input of the OR element and to the second the input of the AND element, the output of which is connected to the input of the integrator to “0”, the input of the operating mode of which is connected to the output of the OR element, the mode setting unit and the logical device, the first input of which is connected to the output of the second threshold device, the eleventh, eighth, fifth and the second inputs are connected respectively with the first through fourth outputs of the control unit, the twelfth, ninth, sixth and third inputs, respectively, with the first through fourth outputs of the mode setting unit, the fourth, seventh and tenth inputs are with the output of the first about the threshold device, and the output is with the control input of the recording unit.

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