SU875319A1

SU875319A1 - Device for measuring variable magnetic field induction

Info

Publication number: SU875319A1
Application number: SU802885334A
Authority: SU
Inventors: Махкамбай Мирзабаев; Константин Дмитриевич Потаенко; Геннадий Михайлович Шишков; Михаил Михайлович Мансуров
Original assignee: Физико-Технический Институт Им.С.В.Стародубцева Ан Узбсср
Priority date: 1980-02-21
Filing date: 1980-02-21
Publication date: 1981-10-23

Description

Изобретение относится к магнитоиз]мерителъной технике и может быть использовано для измерения магнитных, полей.The invention relates to magneto] measuring technique and can be used to measure magnetic fields.

Как известно, при использовании датчиков Холла, для измерения переменных магнитных полей, в контуре, образованном холловской цепью возникает индуцированное ими напряжение. Это напряже-. ние приводит к снижению точности измерений. При питании переменным током, ' частоты Холловского напряжения и напряжения, инрупиррванного в холловской цепи магнитным полем различны й метут быть легко разделены при помощи избирательной цепи.As you know, when using Hall sensors to measure alternating magnetic fields, the voltage induced by them arises in the circuit formed by the Hall circuit. It is tense. This leads to a decrease in the accuracy of measurements. When supplied with alternating current, the frequencies of the Hall voltage and the voltage in the magnetic circuit in the Hall circuit are different, they can easily be separated using the selective circuit.

Известно устройство, включающее дополнительные компенсационные контуры, которые представляют собой рамки, конструктивно объединенные с датчиком. Каждая из рамок расположена симметрично относительно линии, на которой расположены входные или выходные электроды. Ток питания датчика подводят к свобод2 ному входному электроду и дВижку потенциометра, выходное напряжение снимается аналогичным путем flj .A device is known that includes additional compensation loops, which are frames structurally integrated with the sensor. Each of the frames is located symmetrically relative to the line on which the input or output electrodes are located. The sensor supply current is supplied to a free input electrode and a LOT of a potentiometer; the output voltage is removed in a similar way flj.

Однако расположение контуров вокруг датчика приводит к увеличению ширины датчика^ а неизбежное пересечение контуров увеличивает толщину датчика, что не всегда приемлемо, особенно при измерениях магнитных полей в малых объемах и узких зазорах. Кроме того, необходимость симметричного расположения рамок, вызывает трудности прецезионного перемещения проводников и закрепления их.However, the arrangement of the contours around the sensor leads to an increase in the width of the sensor, and the inevitable intersection of the contours increases the thickness of the sensor, which is not always acceptable, especially when measuring magnetic fields in small volumes and narrow gaps. In addition, the need for a symmetrical arrangement of the frames causes difficulties in the precision movement of the conductors and their fastening.

Известно также устройство, которое включает в себя датчик Холла и компенсационную петлю, образованную одним или несколькими витками провода, размещенную в одной плоскости с датчиком Холла, сказывающуюся таким образом под воздействием приложенного к датчику переменного' магнитного ноля L2J .A device is also known that includes a Hall sensor and a compensation loop formed by one or more turns of wire placed in the same plane as the Hall sensor, which thus affects under the influence of an alternating magnetic field L2J applied to the sensor.

Однако, вследствие неоднородности магнитного поля, напряжения индуцируемые в холловской цепи датчика и в расположенной рядом компенсационной петле различны по величине и компенсация оказыj вается недостаточно полной.However, due to the inhomogeneity of the magnetic field, the voltages induced in the Hall circuit of the sensor and in the adjacent compensation loop are different in magnitude and the compensation is not complete enough.

Цель изобретения - повышение точное- ₅ти измерения индукции переменных Магнитных полей.The purpose of the invention is to increase the accuracy of ₅ measurements of the induction of alternating magnetic fields.

Поставленная цель достигается тем,.' что в устройство для измерения индукции переменного магнитного поля, содер- |₀жащее датчик Холла, последовательно соединенные со средней точкой делителя напряжения усилитель переменного тока, выпрямитель и регистрирующий прибор, а выход делителя напряжения соединен с _<5холловской цепью датчика Холла через первый конденсатор, дополнительно введены катушка индуктивности и второй конденсатор, причем катушка индуктивности подключена к токовому электроду датчи- ₂θ ка Холла, первый конденсатор включен между холловским электродом и выходом делителя, а вход делителя соединен через второй конденсатор с токовой цепью датчика. ₂₅ The goal is achieved by. ' that the device for measuring the induction of an alternating magnetic field contains | ₀ Hall sensor, connected in series with the midpoint of the voltage divider, an AC amplifier, a rectifier and a recording device, and the output of the voltage divider is connected to the Hall sensor circuit _<5 through the first capacitor, an inductor and a second capacitor are additionally introduced, and the inductor is connected to Hall current sensor ₂ θ ka, the first capacitor is connected between the Hall electrode and the output of the divider, and the input of the divider is connected through the second capacitor to the current circuit sensor. ₂₅

Повышение точности измерения достигается за счет, того, что площади холловского и токового индукционного контура пронизываются одним и тем же магнитным потоком. Отсутствие добавочной ком- ₃θ пенсационной петли приводит к уменьшению габаритов датчика, упрощает его конструкцию и облегчает его использование внутри объемов· криостатов.Improving the measurement accuracy is achieved due to the fact that the areas of the Hall and current induction circuits are penetrated by the same magnetic flux. The absence of an additional compensation loop θ ₃ leads to a decrease in the size of the sensor, simplifies its design and facilitates its use inside the volumes of cryostats.

На чертеже изображена блок - схема устройства для измерения индукции пере- ³⁵менного магнитного поля.The drawing shows a block - diagram of the device for measuring the induction transferred ³⁵ alternating magnetic field.

Устройство для измерения индукции переменного магнитного поля содержит датчик 1 Холла, первый конденсатор 2, второй конденсатор 3 переменной емкости, ⁴⁰делитель напряжения, состоящий из резистора 4 и переменного резистора 5, усилитель 6 переменного тока, выпрямитель 7, регистрирующий прибор 8, источник 9 питания и катушка 10 индуктивности. ⁴⁵ A device for measuring the induction of an alternating magnetic field contains a Hall sensor 1, a first capacitor 2, a second variable capacitor 3, ⁴⁰ a voltage divider consisting of a resistor 4 and a variable resistor 5, an AC amplifier 6, a rectifier 7, a recording device 8, a power source 9 and an inductor 10. ⁴⁵

Устройство работает следующим образом.The device operates as follows.

.Токовые электроды датчика 1 Холла подключены к делителю напряжения таким образом, чтобы протекающие через вход 50 делителя, т. е. резистор 4 токи, индуцированные в холловской и в токовой цепях были направлены встречно. Первый и второй конденсаторы 2 и 3 служат для электрической развязки по постоянному току ‘55 холловской и токовой цепей. Для обеспечения сдвига фаз токов,· протекающих через резистор 4, на 180°, один из кон денсаторов, а именно второй конденсатор 3 (чтобы сопротивление холловской цепи оставалось неизменным), делается переменной емкости. Изменяя сопротивление резистора 5 добиваются компенсации индуктированной в холловской цепи наводки. Таким образом, варьируя, при отключенном источнике 9 питания, значениями емкости конденсатора 3 и сопротивления резистора 5, добиваются минимальных показаний регистрирующего прибора 8,. т. е. максимальной компенсации индуцированного в холловской цепи напряжения. Катушка 10 индуктивности необходима, чтобы не пропускать индуцированный в токовой цепи переменный ток через источник 9 питания, в случае применения источника питания с малым внутренним сопротивлением (генератора тока).. The current electrodes of the Hall sensor 1 are connected to the voltage divider so that the currents flowing through the input 50 of the divider, that is, the resistor 4, are directed in the opposite direction. The first and second capacitors 2 and 3 are used for electrical isolation of direct current ‘55 Hall and current circuits. To ensure a phase shift of the currents flowing through resistor 4 by 180 °, one of the capacitors, namely the second capacitor 3 (so that the resistance of the Hall circuit remains unchanged), is made of variable capacitance. By changing the resistance of the resistor 5, compensation of the induction induced in the Hall circuit is achieved. Thus, by varying, when the power supply 9 is turned off, the values of the capacitance of the capacitor 3 and the resistance of the resistor 5, achieve the minimum readings of the recording device 8 ,. i.e., the maximum compensation of the voltage induced in the Hall circuit. The inductor 10 is necessary so as not to pass the alternating current induced in the current circuit through the power source 9, in the case of using a power source with a small internal resistance (current generator).

Отметим, что протекание тока, индуцированного в токовой цепи вызывает появление на холловских электродах добавочного напряжения Холла Ц, , которое вносит погрешность в измерения. Поэтому предлагаемое устройство целесообраз но использовать в тех случаях, когда добавочное напряжение Холла U, было.Note that the flow of current induced in the current circuit causes the appearance of an additional Hall voltage C on the Hall electrodes, which introduces an error in the measurements. Therefore, the proposed device is advisable to use in cases where the additional Hall voltage U was.

значительно меньше напряжения, индуцируемого в холловской цепи магнитным полем Un , т. е. чтобы выполнялось условие XL «4.significantly less than the voltage induced in the Hall circuit by the magnetic field Un, i.e., so that the condition XL ~ 4 is satisfied.

UQ.UQ.

Так как U₂= S₂^p» где - плошадь петли, образованной · холловскими выводами;Since U ₂ = S ₂ ^ p ”where is the area of the loop formed by the Hall conclusions;

**

- скорость изменения магнитной • · ав ·- rate of change of magnetic • · av ·

0—4 -γ— индукции и так как /» ί α z.0-4-γ are inductions and since / »ί α z.

где R - постоянная Холла;where R is the Hall constant;

В - магнйтная индукция; а - толщина датчика;B - magnetic induction; a is the thickness of the sensor;

5₁- площадь петли, образованной токовыми выводами;5 ₁ - the area of the loop formed by the current leads;

Z — полное сопротивление цепи, состоящей из сопротивления между токовыми электродами датчика, конденсатора 3 и резисторов 4 и 5, то a, ΖZ is the impedance of the circuit, consisting of the resistance between the current electrodes of the sensor, capacitor 3 and resistors 4 and 5, then a, Ζ

Следовательно, условие «-( выполняется при ^υ2.Therefore, the condition “- (is satisfied when ^υ 2.

2-Sg2-sg

SiSi

Для эпитаксиального арсенидгаллиевого датчика Холла с ёГ = 10 мкм = 10~⁵м, ^{R =} Αθ (^ПР^{И п =} 6_дЮ^ см’²) и при 1 тл, величина 100см, т. е'.For an epitaxial gallium arsenide Hall sensor with eG = 10 μm = 10 ~ ⁵ m, ^{R =} Αθ ( ^P R ^{I n =} 6_dU ^ cm ' ² ) and at 1 T, the value is 100 cm, i.e.

условие « 1 легко выполнимо если величину ~2. выбрать порядка нескольких десятков килоом. Отметим, что увеличивая сопротивление резистора 4, а значит и полное сопротивление 2 , можно добиться выполнения условия ~jL «1 для любых значений В и о| .condition “1 is easily satisfied if the value is ~ 2. choose about several tens of kilo-ohms. Note that by increasing the resistance of resistor 4, and hence the impedance 2, it is possible to satisfy the condition ~ jL «1 for any values of B and o | .

Использование предлагаемого устройства повышает точность измерения переменных магнитных полей при питании от источника постоянного тока за счет того, что площади холловского и токового индукционного контура пронизываются одним и тем же магнитным потоком. Отсутствие добавочной компенсационной петли не вызывает увеличения габаритов датчика, что особенно важно при исследовании магнитных полей в малых объемах и узких зазорах (например, в зазорах электрических машин, магнитных головках и т. д.), упрощает его конструкцию и технологию изготовления датчика и облегчает его использование внутри объемов криостатов.Using the proposed device improves the accuracy of measuring alternating magnetic fields when powered by a direct current source due to the fact that the areas of the Hall and current induction circuits are penetrated by the same magnetic flux. The absence of an additional compensation loop does not increase the size of the sensor, which is especially important when studying magnetic fields in small volumes and narrow gaps (for example, in the gaps of electric machines, magnetic heads, etc.), simplifies its design and the manufacturing technology of the sensor and facilitates it use inside volumes of cryostats.

Claims

(54) DEVICE FOR MEASURING THE INDUCTION OF VARIABLE MAGNETIC FIELDS The invention relates to a magnetism of measuring technique and can be used to measure magnetic flues. As is well known, when using the Dutch Hall, for measuring variable magnetic fields, the circuit generated by the Hall Peak has a hint of heat induced by them. This finding leads to a decrease in measurement accuracy. When powered by an alternating current, the frequency of the voltage of the voltage and voltage that is induced by the magnetic field in the Hoplow center of the magnetic field is different, “h can be separated from the local circuit. And a hes-gao device, including additional compensation circuits, which are frames structurally combined with the sensor. Each side of the frame is located on a perimeter line, on which the input or output electrodes are located. The da da current is supplied to the free input electrode and the potentiometer dips, the output voltage is removed in a similar way Ij However, the location of the circuits around the sensor leads to an increase in the width of the sensor and the inevitable intersection of the circuits increases the thickness of the sensor, which is not always acceptable, especially when measuring magnetic fields in small volumes and narrow gaps; In addition, the need for a symmetrical arrangement of the framework causes difficulties in moving the conductors and securing the JXX. It is also known a device that includes a Hall sensor and compensation looping in one or several turns of a wire placed in a plane with a Hall sensor, thus under the air: tBHeM applied to the sensor alternating magnet on the floor SSC. However, due to the inhomogeneity of magnets (the field, the voltages indupirgee 38 in the Hoplov sensor circuit and in the adjacent compensation loop are different in magnitude and the compensation is not sufficiently complete. The circuit of the invention is variable accuracy in the measurement of the induction of variable Magnetic fields. / that the device for measuring the induction of an ac magnetic field containing an Khsla sensor, connected in series with the midpoint of a voltage divider, an ac amplifier, The voltage meter divider is connected to the Hall circuit of the Hall sensor through the first capacitor, the inductor and the second capacitor are added, the inductor is connected to the current electrode of the Hall sensor, the first capacitor is connected between the Hall electrode and the divider output, and the input of the divider is connected via a second capacitor to the current circuit of the sensor. An increase in the measurement accuracy is achieved due to the fact that the area of the Hall II current induction KOHiypa is permeable are the same magnetic flux. The absence of an additional compensation loop leads to a reduction in the overall dimensions of the sensor, simplifies its design and facilitates its use inside cryostat volumes. The drawing shows a block diagram of a device for measuring the induction of an alternating magnetic field. A device for measuring the induction of a variable magnetic field contains a Hall sensor 1, a first capacitor 2, a second variable capacitor 3, a voltage divider consisting of a resistor 4 and a variable resistor 5, an AC amplifier 6, a rectifier 7, a recording device 8, power supply 9 and inductance coil 10. The device works as follows. The current electrodes of Hall sensor 1 are connected to a voltage divider so that the divider flowing through the input, i.e. the resistor 4, currents induced in the Hall and current circuits are directed oppositely. The first and second capacitors 2 and 3 are used for electrical isolation over the direct current of the Hall and current circuits. To ensure the phase shift of the currents flowing through the resistor 4, by 180, one of the capacitors, namely the second capacitor 3 (to keep the resistance of the Hall circuit unchanged), is made variable capacitance. By varying the resistance of the resistor 5, compensation is achieved for the induction induced in the Hall circuit. Thus, by varying, with the power supply 9 disconnected, the values of the capacitance of the capacitor 3 and the resistance of the resistor 5 achieve the minimum readings of the recording device 8 ,. i.e. maximum compensation of the voltage induced in the Hall circuit. The inductance coil 10 is necessary in order not to pass the alternating current induced in the current section through the power supply 9 in the case of using a power supply with a low internal resistance (current generator). Note that the flow of current induced in the current circuit occurs at the Hall electrodes of the additional Hall voltage U, which introduces an error in the measurements. Therefore, the proposed device is advisable to use in those cases where the additional Hall voltage U was. significantly less than the voltage induced in the Hall circuit by a magnetic field (JQ, i.e., to satisfy condition iiL ". Since u, 8g | where Sfj is the area of the loop formed by the Hall displays; - the rate of change of the magnetic field S induction and since y .-- iL-. At, where R is the Hall constant, 6 is magnetic induction, a is the sensor thickness, the area of the loop formed by the current leads, Z is the impedance of the circuit consisting of the resistance between current electrodes of the sensor, capacitor 3 and resistors 4 and 5, then JiL ftll ± Uo 3 SA z Therefore, the condition -1 "is PTARTT CT | -b. S d Dp of the epitaxial Hallplate arsenide sensor with I 10 microns, I 10-3 (with n 6 .loW and with B 1 tl, the value is UOsm, t. Condition -j ". 1 is easily fulfilled if 2. Choose the order of several tens of kilo. Note that by increasing the resistance of the resistor 4, and hence the impedance 2, you can achieve a complete condition-b - h for any values:, В and о |. The use of the proposed device increases Accuracy of measurement of alternating magnetic fields when powered from a DC source due to the fact that the area of the Hall o and the current induction loop are permeated by the same magnetic flux. The absence of an additional compensation loop does not cause an increase in the dimensions of the sensor, which is especially important when studying magnetic fields in small volumes and narrow gaps (for example, in gaps of electrical machines, magnetic heads, etc.), simplifies its design and manufacturing technology of the sensor and facilitates its use inside cryostat volumes. Apparatus of the Invention A device for measuring the induction of an alternating magnetic field, containing a Hall sensor connected in series with the midpoint of a voltage divider, an AC amplifier, an expander and a recording device, and a voltage divider connected to the Hall circuit of the Hall sensor through a first capacitor, which This is due to the fact that, in order to improve the measurement accuracy, an inductance coil and a second capacitor are added to it, with the inductor connected to the current at the Hall sensor, is connected between the first capacitor electrode and the Hall output of the divider, and divider input is connected via a second capacitor with a current sensor circuit. Sources of information taken into account in the examination 1.Panchishin Yu. M., Usateno S. G. Measurement of alternating magnetic fields. Kiev, Technique, 1973, p. 78-79.

2. Afanasyev Yu. V., Studentsov N. V., Schelkin Ai P. Magnetometric converters, devices, installations. Energy Leningrad branch, 1972,. 2O2-2OZ.