FI57666B - NUMBER OF INDICATOR INSTRUMENTS FOR ELECTRIC MOTOR CRAFT WITH HALL-EFFECT-ANORDING - Google Patents

Description

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Patent- och ragisteratyralaan Anaektn utlagd och utl. * Krift * n publkerad 30.05.80 (32) (33) (31) Requested ttuoikeu * —Begird priority (71) Institut Elektrodinamiki Akademii Nauk Ukrainskoi SSR, Brest-Litovsky Prospekt 102, Kiev, USSR (SU) (72) Sergei Glebovich Taranov, Kiev, Voldmir Vasilievich Braiko, Kiev,

Jury Trofimovich Chigirin, Kiev, Vladimir Petrovich Belousov,

Kiev, USSR (SU) (7 * 0 0y Kolster Ah (5 ^) Numerical indicating device for the electromotive force of a Hall-phenomenon device -Numerical indicating instruments for electromotive motors of the Hall effect effect

The invention relates to an electromotive force indicating device for a Hall effect device and, more particularly, to a numerical indicating device for the electromotive force of a Hall effect device, which can be used in various devices in which Hall's phenomena are exploited.

A numerical indicating device for the electromotive force of a Hall effect sensor is known, in which one pair of electrodes of the Hall electromotive power sensor of opposite polarity is connected to a voltage source and another pair of electrodes of opposite polarity is connected to a "voltage code" converter, which in turn is connected to a numerical indicator. The ‘voltage code’ converter encodes the output voltage of the sensor generated over electrodes of opposite polarity of the latter pair and is indicated by a numerical indicating device.

Analog devices for measuring the electromotive force of a Hall phenomenon device are also known, in which the effect of a non-DC potential voltage on the electromotive force of the Hai 1 phenomenon is eliminated. These measuring devices comprise a Hall effect device in which an oil pair of electrodes of opposite polarity is connected, one pair being connected via a selector switch to a voltage source and the other pair 2 56666 being connected via a selector switch to an electrode force indicating device of a Hall effect sensor. The purpose of the selector switch is to provide an alternating connection between the two electrode pairs of the Hall effect sensor and the voltage source resistance device of the voltage source. Thus, when the second pair of electrodes is connected to the voltage source, the second pair is connected to the indicating device and vice versa.

When the sensor is irreversible with respect to the Hall electromotive force and reversible with respect to the non-DC potential voltage, the sensor output voltage generated alternately over said two electrode pairs represents the sum of the Hall electromotive force and the non-DC potential voltage pair during the odd cycle of selector switch operation. the difference between them during the period.

The angular displacement of the pointer of the electromotive force indicating device of the Kali phenomenon device is proportional to the average of the absolute levels of the output signals generated over each pair of electrodes, i. The value of the electromotive force of the Hall effect device, and thus does not depend on the non-DC potential voltage.

Thus, the operation of the device described above is based on the alternating connection of two pairs of electrodes and the device includes an indicating device for indicating the averages of the absolute levels of the output signals of the Hall effect device and with a relatively large time constant.

However, the known numerical indicating device for the electromotive force of the Hall effect device has a number of drawbacks.

First, the measurement accuracy is relatively poor when the signals from the Hall effect device are weak due to the effect of the non-DC potential voltage of the sensor, which, despite being corrected or compensated, is unstable with time and exposed to ambient temperature.

Second, the known indicating devices are practically incapable of measuring the true value of the hall-electromotive force in cases where the non-DC potential voltage is not easily distinguishable from the sensor electromotive force, i. when the two signals are similar.

Third, the measurement time is relatively long, which is due to the fact that it is forced to manually reset the instrument to zero before measurement. This fact, which complicates the use of a known indicating device for measuring the electromotive force of a Hall effect sensor when the duration of the latter is shorter than the time necessarily required to reset to zero, or makes the use of such a known indicating device completely impossible.

in addition, with the known indicating device, it is difficult to achieve a fully automatic measurement and detection of the electromotive force of the Hall effect device.

On the other hand, the analog device described above for indicating the electromotive force of the Hall effect device also has drawbacks.

3 57666

First, the measurement accuracy of the Hall electromotive force is not sufficient due to the effect of coupling interference.

Secondly, the operating speed of the instrument is insufficient because the output voltage of the sensor must be thoroughly filtered.

Third, the device is not reliable enough due to the repeated switching cycles of the selector switch.

However, it is impossible to directly use the Hall effect device described above, in which the electrodes are connected as described, in a known numerical indicating device of the electric motor power of the Hall effect device, because during each successive period of operation of the "voltage code" converter of the numerical indicating device-- information representing the value of the input voltage during the previous period is lost.

The object of the invention is to avoid these drawbacks.

The object of the invention is to provide an electric motor for a Hall effect device. a numerical force indicating device in which it is not necessary to perform the setting to zero before the measurement.

This object is achieved by means of a numerical indicating device for the electromotive force of the Hall effect device, in which pairs of electrodes of opposite polarity are alternately connected by a selector switch to a voltage source and a "voltage code" converter connected to a numerical indicating device further characterized by which determines the end time of the coding period, wherein the input of said element is connected to said "voltage code" switch and its output is connected to said selector switch as well as to said converter.

It is desirable that the numerical indicating device for the electromotive force of the Hall effect device according to the invention further includes a phase sensitive means adapted to generate a control signal acting on said "voltage code" converter when the value of the non-DC potential voltage of said Hall effect device rises larger, wherein the second input of said phase sensitive member is connected to the output of said selector switch, the second input being "connected to said voltage source and the output being connected to said" voltage code "converter.

The numerical indicating device of the electromotive force of the Hall effect device according to the invention completely eliminates the effect of the non-DC potential voltage on the value of the electromotive force, which becomes expressed, whereby the accuracy, sensitivity and operating speed of the instrument are improved.

An embodiment of the invention will now be described in detail with reference to the accompanying drawings, in which Figure 1 shows a block diagram of a numerical indicating device for the electromotive force of a Hall phenomenon device according to the invention, Figure 2a shows a diagram showing the variation of permanent magnet induction 2 with respect to time; a diagram showing the variation of the supply current of the Hall smv device and the reference voltage with time, * 57666 Fig. 2c shows a diagram showing the variation of the total output voltage of the Hall smv device with time, Fig. 2d shows a comparison of the absolute value of the output voltage of the Hall smv device with time Fig. 2e shows a diagram showing the time variation of the code of the "voltage code" converter performing the output voltage-coding of the Hall-smv device, Fig. 2f shows a diagram showing the "voltage code", and a diagram showing the "voltage code" the time variation of the pulse signal at the output of the "ode" converter, Fig. 2g shows a diagram showing the time variation of the output voltage of the determining element at the end of coding, Fig. 2h shows a diagram showing the time variation of the output voltage of the phase sensitive element, Fig. 2j shows a diagram temporal variation in the expression of the instrument.

The numerical indicating device for the electromotive force of a Hall device according to the invention comprises a Hall device (Fig. 1) with two pairs of electrodes 2, 3, respectively, of opposite polarity. 4, 5, which are connected via a selector switch 6 to a voltage source 7 and a "voltage code" converter 8 connected to a numerical indicating device 9. This apparatus further comprises means 10 for determining the end of coding operation, the input of the element 10 being connected to the converter 8 and its output is connected to selector switch 6 and the same converter 8.

The function of the selector switch 6 is to alternately connect the electrode pairs, i.e. first the second electrode pair of the Kali device 1, e.g. electrodes 2 and 3, to the source 7, while the second pair, i.e. the electrodes 4 and 5, is then connected to the "voltage code" converter 8, and then the switching order is reversed.

The "voltage code" converter 8 may be a time pulse type or a frequency pulse type or some other code pulse type.

The means 10 for determining the end time of the coding operation is intended to determine the moment when the converter 8 terminates the coding operation of the output voltage of the Hall device 1 and then to generate a control signal acting on the selector switch 6 and the converter 8. Said member 10 provides a measurement of the electromotive force of the Hall device for at least two periods. The numerical indicating device can also be heard by a phase-sensitive element 11, the second input of which is connected to the output of the selector switch 6 and the second input of which is connected to the voltage source 7 and the output of which is connected to the "voltage code" converter 8.

The device according to the invention operates in the following way:

Before measuring the electromotive force of the Hall device, the initial setting of the "voltage code" converter 8 of the selector switch 6 (Fig. 1) and the determining element 57666 at the end of the coding operation is performed.

When the Hall device 1 (Fig. 1) is actuated, for example by means of a permanent magnetic induction "B" (Fig. 2a) and when, for example, a sinusoidal alternating current "i" (Fig. 2b) is supplied via electrodes 2, 3 (Fig. 1) of opposite polarity, which, when the selector switch 6 is in its initial position connected to the voltage source 7, a voltage "u ^" (Fig. 2c) occurs over the second pair of electrodes 4, 5, the voltage "u ^" being formed together by the Hall electromotive force "εχ" and the non-equipotential voltage Mu M .

The non-DC potential voltage "u" is generated by the current "i" passing through the electrodes 2, 3 of the Hall device (Fig. 1) and is caused by the previously mentioned electrodes 4, 5 connected to the non-equal potential points of the plate of the Hall device 1. The value of the non-DC potential voltage "Up" depends on the resistivity of the Hall device and is proportional to the value of the supply current.

Assume that the Hall electromotive force "e" and the non-DC potential "λ nite" Up "are in phase (Fig. 2c), whereby the instantaneous value of the output voltage generated over the electrodes 4, 5 (Fig. 1) is obtained from the theorem U / i = (e ^ + u) s in UT t 1 xm pm o where e ^ and u ^ are the maximum values of the Hall electromotive force and the non-DC potential voltage and is the angular velocity of the supply current Mi ".

At the beginning of the measurement "t" (Fig. 2d), the "voltage code", the converter 8 (Fig. 1), e.g. of the time pulse type and connected to the electrodes 4, 5 via the selector switch 6, provides the absolute output voltage of the Hall device 1 (Fig. 1). encoding the value / uj / (Fig. 2d) by comparing it, for example, with a linearly varying reference voltage "u" (Fig. 2d) The result of the coding operation, i.e. the value "h ^" (Fig. 2e) is stored as a numeric static code "H" "voltage code ,, to the memory of converter 8 (Figure 1).

If the converter 8 is of the code pulse type, it is essential that the numerical indicating device of the electromotive force of the Hall effect device, in addition to the reversible counter normally included in these types of converters between the "voltage code converter 8" and the numerical indicating device 9, include a reversible auxiliary counter (not shown). is also placed between the converter 8 and the indicating device 9, the purpose of the auxiliary counter being to store the output voltage "u> |" of the Hall device. the result of the coding.

The moment "t ^" (Fig. 2d) at which the coding of the absolute value "u ^" of the output voltage of the Hall device 1 (Fig. 1) ends and which forms the end time of the first measurement period "I" (Fig. 2d) is determined by the member 10 (Fig. 1), and at that moment a pulse signal "Ug" (Fig. 2f) is transmitted from the converter 8 to the element 10 (Fig. 1). The encoding end determining element 10 generates a control signal "u ^" (Fig. 2g), which acts on the "voltage code" converter 8 (Fig. 1) and the selector switch 6.

Upon receiving this control signal, the "voltage code" converter 8 is ready to encode the next value of the output voltage of the Hall device 1 without resetting the coding result "H ,," of the first period "I" (Fig. 2e). The control signal uses a switch 6 to connect the electrodes 4 and 5 to the source 7 and at the same time to connect the electrodes 2 and 3 to the transducer 8. In this way, the device according to the invention starts the second measuring cycle "II" of the Kali device (Fig. 2d).

As a result of the irreversibility of the electromotive force "ex" of the Hall device and the reversibility of the non-DC potential voltage "u ^" of the same device, the instantaneous value of the voltage "U2" generated over the electrodes 2 and 3 of the Hall device 1 (Fig. 1) Fig. 2c) (taking into account the inversion of the voltage ensured by the corresponding connection of the contacts of the intermediate switch 6): u „= (e - u) sin« vt 2 xm pm o

The irreversibility inherent in the Kall phenomenon device thus provides a phase shift of 180 ° between the Hall electromotive force and the non-DC potential voltage when switching from electrode pair 2, 3 to pair 4 · and 5.

It is known from both theoretical and practical studies that, in the case of an isotropic Hall device, the values of "e" and "u" are the same for both measurement periods described above, with a phase difference of either 0 ° or 180 °. (cf. e.g., RF Wick, "Solution of the Problem of a Hall Electric Field in a Germanic Gyrator," Journal of Applied Physics, Vol. 25, No. 6, 1954).

During the second measuring period "II", the "voltage cc" converter 8, the input of which is connected to the electrodes 2 and 3 via the selector switch 6, encodes the output of the Hall device 1 (Fig. 1) with the absolute value of the voltage A ^ / (Fig. 2d) and adds the current code (Fig. 2e) to the stored code "H 2". The end time (Fig. 2d) of the coding of the output voltage "U2" (Fig. 2c) of the Hall device 1 (Fig. 1) is determined by a member 10 which sends a control signal to interrupt the measurement operation (switching through which the latter control signal acts on the "voltage code" converter 8 for better clarity. therefore omitted from Figure 1).

Thus, the device described herein allows full measurement operation during two consecutive cycles. When the numerical indicating device according to the invention operates automatically, this operation is repeated many times.

At the end of each successive measurement operation, the electromotive force measurement result "N" of the Hall device 1 can be read from the numerical indicator 9 connected to the "voltage code" converter 8. This result is not affected by the non-DC potential voltage "u ^" because the two measurement periods "I" and "II "information representing the total output voltage" u ^ "of the Hall device 1 (Fig. 1) is stored in the converter 8 (Fig. 2c), whereby the absolute value of" u ^ "applies to '1: 7 57666 / ut 1 / u1 / *' V = 2 exm

It should be noted that the above result is correct only on the condition that "e ^" is greater than "u ^". According to the rules for processing absolute values, if "e ^" were less than "upm" 5 then the absolute value of the total voltage would not be proportional to the Hall electromotive force but to the non-DC potential voltage, i.e. / u / = / e + u / + / e - u / = £ xm pm xm pm e + u - e + u = 2u.

xm pm xm pm pm

Correspondingly, when e „is less than u, the correct result can be obtained by subtracting the absolute values of the output voltages of the Hall device, i.e. / u, / = / e + u / - / e - u / = 2 e £ xm pm xm pm xm

To detect the situation when the non-DC potential voltage of the Hall device rises above its electric motor force, a phase-sensitive member 11 is arranged in the apparatus described herein (Fig. 1).

The phase sensitive member 11 operates as follows:

If, during both cycles "I" and "II" of the measurement operation, the reference signal "uo" (Fig. 2b) going from the voltage source 7 (Fig. 1) to the second input of the phase-sensitive member 11 and the output signals "u ^" and "generated over the electrode pairs 4, 5 and 2, 3 u "(Fig. 2c) are in phase with e being greater than u_, so if the value of 2 xm pm e ^ in were less than the value of u ^ m, the signals" uQ "and" u ^ "would be during the first period" I "( Figures 2b and 2c) would be in phase and during the second period "II" the signals "u0" and "U2" (Figures 2b and 2c) would be in opposite phases. This situation is maintained by inverting the output voltage "U2" of the Hall device (Fig. 2c) during the second period "II". The phase change information between "uo" and "^ '-' when e is less than u is indicated by the phase sensitive member 11.

xm r c pm

The output signal "u ^" of the phase-sensitive element 11 (Fig. 2h) is used to reset the converter 8, so that in this case it performs the subtraction of the outputs "H ^" and "H2" of the first and second cycles (Fig. 2e).

The numerically indicating device of the electromotive force of the Hall effect device described here, which also includes the phase-sensitive member 11, achieves a substantially better overall sensitivity because it is possible to measure the electromotive force of the Hall device less than the non-DC potential voltage. In addition, when there is no magnetic field, i.e., e = 0, the indicating device indicates a zero reading because the phase difference between the non-DC potential voltage "u" and the reference signal "uo" changes

Claims (2)

8 57666 from period "I" to period "II" by 180 ° (Figs. 2b and 2c) and therefore the equal outputs of the coding performed during the two periods are subtracted (H ^ = from each other, resulting in zero (H ^ - H2 = 0). The advantages of the numerical indicating device according to the invention compared to the known electrometric force indicating devices of the Hall effect device are higher accuracy, better sensitivity and operating speed, it makes it possible to measure the actual value of the Kali electromotive force and the measuring operation is entirely automatic. A numerical indicating device for the electromotive force of a Hall effect device, wherein pairs of electrodes of opposite polarity are alternately connected by a selector switch (6) to a voltage source (7) and a "voltage code" converter (8) connected to the numerical indicating device, characterized in that it further comprises means (10) for determining the end time of the coding period, the input of said means (10) being connected to said "voltage code" converter and its output being connected to said selector switch (6) as well as to said converter (8). A numerical indicating device for the electromotive force of a Hall effect device according to claim 1, characterized in that it further comprises a phase-sensitive element (11) adapted to generate a control signal acting on said "voltage code" transducer (8) when said The value of the non-DC potential voltage of the Hall device rises above the value of the electromotive force of the device, the second input of said phase-sensitive member (11) being connected to the output of said selector switch (6), the second input being connected to said voltage source (7) and its output connected to said "voltage code" converter (8).