DE2333080A1 - Electronic measuring appts. using Hall voltage - has device removing effect of non-equipotential voltage on Hall voltage based on evaluation of irreversibility of Hall transmitter - Google Patents

Abstract

The transmitter is alternately supplied via one of two pairs of opposite electrodes. The output signal is taken from the other pair of electrodes. According to the mean value of the absolute levels of at least two successive output signals, the true value of the HAll voltage is assessed. The transmitter is supplied via each pair of opposite electrodes the same amount of currents but of different frequency. The output signals are taken from the same pair of electrodes. They are selected according to the frequency and rectified.

Description

Dipl.-Fog. Dr. jnr.

Frank Arnold Mix

Patent attorney

frankftirt am Main 70

Gartenstrasse 123 2333080

PROCEDURE FOR ELIMINATING THE INFLUENCE OF NON-EQUIPOTENTIAL VOLTAGE ON THE REAL VOLTAGE AND EQUIPMENT FOR ITS REALIZATION

The present invention relates to the field of Elektromeßtechnlfc, In particular, the Nichtäquipotentialspannung the EIlK a Hall sensor and to the emf of the Hall effect sensor in a cascade and FCQ pn in various constituent on the Hall effect devices are used to a method and means for eliminating the influence "

There are procedures for eliminating the influence of the non-equivalent potential voltage on the Hall voltage known, which can be divided into three methods: the first method is based on a compensation of the non-equipotential voltage of the Encoder in the absence of the magnetic field in analogy to compensation a detuning voltage on a Weatstone bridge that

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the second - on a compensation of the non-equipotential voltage by an auxiliary magnetic field acting on the Hall sensor »the third - on a compensation of the non-equipotential voltage by an In the output circuit of the sensor (see for example M, E. Masurow" Electronic devices with Hall sensors and magnetic resistances ", ZIfIIPX ₉ Moscow, 1965) acting counter-voltage,

In the case of a cascade connection of the Hall sensors, the influence the equal potential voltage on the EUK of each

JL,

Hallgebers in similar catfish eliminated

The disadvantage of the known methods is a large one the influence of the non-equivalent potential voltage on the EMF of the Encoder-related error, which is caused by the correct

A A

yawed non-equivalent potential voltage due to a temporal and temperature instability of the parameters of the hall sensor and the Corrective circuit itself is produced «

The other disadvantage of these methods is that it is impossible to determine the true value of what is acting on the donor To determine the magnetic field, well in many cases the non-equivalent potential voltage cannot be separated from the Hall voltage

A disadvantage of the methods under consideration is also a considerable correction for the non-equipotential voltage _f vas its use for measuring and recording magnetic and electrical parameters if the change in the parameters mentioned is less than that for correcting the non-equipotential voltage.

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must be compensated "- potential voltage required 1st tent, difficult or impossible did this mainly affects the wechselstroagespelsten Hall sender, as in this case, the Nichtäqulpotentlalspannung is a complex value and after _such wel parameters - its active and Bllndantell

With a cascade connection the Hall sensor takes accordingly the correction tent for the non-equipotential tension and the number of regulations on »

In addition, the known methods have the disadvantage suggest that it is impossible to do this with the automation of the Compensation process for the non-equipotential voltage the effect on the Hall sender and the Hall sender in cascade connection to apply a magnetic field *

A common shortcoming of the latter two procedures There is also the need for auxiliary sources for magnetic or electrical fields to create the compensation voltages to use · Their other shortcoming is a disturbance in the compensation of the non-equivalent potential voltage when changing the Hall sensor supply currents · This is particularly useful for a cascade connection of the Hall sensors applies, since the output voltage of the previous sensor is used to feed the next Sensor and changes depending on the size of the magnetic field to be measured *

Devices for eliminating the influence of the non-equipotential voltage on the Hall voltage are also known, who realize the above procedures · For example to implement the first method between the

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opposing Hall electrodes or those of each

ft

Hall sensors with their cascade connection In the simplest case switched a rheostat, through its regulation a Compensation of the non-equivalent potential voltage is achieved what a ^ in compensation of the detuning voltage with an equivalent Bridge circuit of the Hall sensor equals "

Disadvantage of said device is its considerable temporal and temperature instability. The other disadvantage exists In the need for careful control of the compensation elements in the measuring and recording process, what with is related to a significant loss of tent · Besides, they are Badly suited for work and cannot be used in digital devices be used as they meet the requirements in terms of their accuracy and rapid action by far «

The purpose of the present invention is to achieve the above Avoid disadvantages «

The invention is based on the task of reducing the influence of the Non-equivalent potential voltage on ale EMF of a Hall sensor and to exclude the IVK of the hall sensors in cascade connection

This problem is solved in a ate on the Evaluation of the reversibility of the Hall sensor building Procedure for eliminating the elnilus of the non-equipotential voltage alternately to the nail tension of the encoder according to the invention ubtr that one of the two pairs of opposing electrodes fed and the output signal at the other electrical

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the pair aD taken and according to the mean of the absolute Level of at least two successive output signals is judged via the true value of the Hall voltage, as well as

in that in that on the evaluation of the irreversible cold The process that builds on the Hall sensor to eliminate the influence of the non-equipotential voltage on the Hall voltage the encoder according to the invention over each pair of the opposite Electrodes are fed by currents that are the same in magnitude and different in frequency, wfcbel on the same electrode pairs Output signals can be picked up, which are further described in the frequency can be selected and rectified and then according to the mean value of the absolute levels of the two converted Signals are judged about the true value of the Hall voltage

The device for the implementation of a method in which the one pair of opposite Hall electrodes with the Supply source and the other with a Hall voltage indicator coupled 1st, contains according to the invention a changeover switch, with the aid of which the said pairs of electrodes are alternately connected to the Hall voltage indicator or to the supply source will·

It is advisable to use the switch for the Hall electrodes in this device as an electromechanical switch carry out at least two pairs of changeover contacts, the movable contacts of one pair with the supply source, the moving contacts of the other pair with the Hall voltage indicator and any immovable normally closed contact

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of one pair with the corresponding immobile normally open contact of the other pair and in turn with one the corresponding Hall electrodes are connected, the control circuit of the switch being coupled to a control generator Is·

The facility for implementing the other procedure, in which one pair of the opposite flallel electrodes with the supply source is connected, according to the invention contains a

A. A.

connected to the other pair of opposing electrodes additional supply source, the frequency of which differs from the frequency the above-mentioned supply source differs by an even multiple, and two phase-sensitive rectifiers, their inputs each with the corresponding pairs of the opposite

* ■ A

Electrodes and the outputs of these rectifiers with the input a summator connected to the Hall voltage indicator are coupled "

The device can have a second Hall sensor with two pairs the opposite electrodes, an additional switch and one to the supply source via the switch for the elec-

* A

Troden of the first Hall sensor connected supply voltage shaper for the second Hall sensor included, while the output This former is connected to the additional changeover switch, with the help of which the said pairs of the opposite Electrodes of the second Hall sensor alternately to the supply voltage shaper or * to the one with the outputs of the additional Switch coupled Hall voltage indicator connected

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will·

Expedient catfish is a second Hall sensor

A-

with two pairs of opposing electrodes and one additional supply voltage shaper for this device containing each pair of the opposing electrodes of the Encoder to the appropriate phase-sensitive mentioned Rectifier and connected to the corresponding output of the additional voltage shaper, in which the bingangles

an over corresponding frequency selektwda with the pairs of opposite electrodes of the first Hall sensor and the other inputs of this additional shaper to the aforementioned

a>

Power sources are switched

The invention is intended below on the basis of an example of implementation and drawings are explained in more detail.

A A

It shows:

Fig. 1a and Fig.1b - schematically one in the device for eliminating the influence of the non-equipotential

voltage to the Hall voltage used Hall sensors as irreversible Quadrupole according to the invention;

Fig. 2a - a block diagram of the device for elimination the influence of the equilibrium potential voltage on the

Hall voltage according to the invention;

Fig. 2b and 2c - two possible circuit variants for the

A a

Contacts of the changeover switch in the establishment for elimination the influence of the non-equipotential voltage on the Hall

voltage according to the invention;

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Figure 3 is a block diagram of the elimination device the influence of the non-equipotential voltage on the Hall voltage with a frequency selection of the output signals according to the invention;

Fig. 4 is a block diagram of the elimination device the influence of the IT non-equivalent potential voltage on the EMF the Hall sensor in cascade circuit according to the invention}

Flg. 5 - a block diagram of the device for elimination the influence of the non-equilibrium potential IaI voltage on the EMF

the Hall sensor in cascade connection with a frequency selection of the output signals according to the invention; Fig, 6a and 6b - current and voltage curves for the input

direction to Flg. 2 when feeding the Hall sensor with a Direct or alternating current according to the invention

When Hall sensor 1 is supplied with current I via the one of the two pairs of opposing electrodes, belsplels-

way 2 and 3 (Fig. 1a), and in the absence of one on the Hall sensor 1 acting magnetic field ^ arises on the other pair of the electrodes 4 and 5, a voltage that is generated by applying said Electrodes at non-equipotential points on the plate of the Encoder 1 is conditional · It is customary to designate this voltage as an EFlchtäqulpotentlalspannung U · The size of the

Non-equipotential voltage; U 1st of the specific resistance of the material of the encoder 1 and proportional to the value of the supply current

With regard to the non-equivalent potential voltage, the Hall sensor is

* A

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a reversible element (its equivalent circuit in the form of a ordinary Wheatston bridge can be represented) and

ßk Jk

plus the Hall voltage β - a non-reversible! element · Das Procedure for eliminating the influence of the non-equivalent potential voltage on the Hall voltage is below on the basis of Flg. 1a explains, in the schematically a square isotropic Hall sensors with the same electrodes and a series of the following operations are shown »

The encoder is with the current I over the opposite

A A

Electrodes 2-3 fed in the direction from the third to the second. The trajectory of the negative charge (of the electron) is drawn in dashed lines · If one imagines that the flux density vector passes through the plane of the drawing, so becomes the electrode 4 negative according to the sixth-hand rule and the electrode 5 positive (the signs are given in circles)

Let us assume that the non-equipotential voltage U a opposite direction (the polarity of the non-equipotential

Λ A

voltage 1st in squares stated) comprises · This is explained by that, due to an equivalent bridge circuit of the Hall sensor, the resistance of Bruckenzwelges * 2 - 5 ^ ⁹ * "QLAE * equality smaller than the resistances of the other Bruck branches (^ 3.4 = ^{Γ 3_ς)} the resistance of the bridge branch r ₂ ^. 1st «

Now imagine that with the same direction of the river density vector of the transmitter 1 with the current I over the electrodes 4-5 in the direction from the fifth to the fourth, i.e. in the direction

the effect of the Hall voltage In the first case, it is fed · Then

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according to FIG. 1b, the direction of the effect of the rope tension is on

the electrodes 2-3 (in Fig. the polarity of the Hall voltage is indicated in circles) opposite the direction of the supply current in the first case (see Fig. 1a), which illustrates that the Hall sensor cannot be reversed. Da * ₂ -5 ^ ^r 2-4 ^{is> lst} ^ ^{& s} potential of electrode 2 higher than that of electrode 31 and

the polarity of the non-equivalent potential voltage U coincides with the

Polarity of the Hall voltage e together · Given that

the direction of the current in the second case does not coincide with the direction of the effect of the non-equivalent potential voltage in the first case, results from the above-mentioned the reversible

A A

kelt of the Hall sensor in relation to the non-equipotential voltage · The absolute value of the output voltage / U ^ / of the sensor is therefore in the first case / U ₁ / = / β _χ - U _p / · .. (1) and in the second - / U ₂ / = / β _χ + U / ··· (2)

If one now adds up these two voltages, fco one obtains a total voltage, the mean value of which is only proportional to the Hall voltage and independent of the I non-equipotential voltage under the condition that / β _χ / ^ / U / According to the rule for algebraic operations with ^ Under the condition that / β _χ / {/ U /, the mean value of the total voltage of the sum of the two signals mentioned is proportional not to the Hall voltage but to the non-equipotential voltage

be, i.e.

/ U ₁ / + / U ₂ / = / e _x - U _p / + / θ _χ + U _p / = 2 2

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* υ _ρ

2 ■■ .- .. In connection with this, it is subject to the condition that

U ^ / ^lst »necessary, the absolute values of the output span ρ

deductions from each other

From Jtheor θ follows tables and experimental research that for an isotropic donor, the modules / _β χ / and / V / are exactly the same in the two cases considered and the phase shift between you 0 ° or 180 ° (see. For example, Wick RF "The Solution to the problem using the electric Hall field in a Gernanlum gyrator ", J. Appl · Phys., Vol. 25, H» 25, 1954 ·). amounts to.

If the Hall sensors in cascade connection represent two sensors of the type mentioned above, then in the first case the absolute value of the output voltage of the cascade connection is equal to / U ₁ / »/ (β _χ ~ Up ₁ ) Bk ₁ - Up ₂ /» / (θ _χ1 - U _p3 ) k - Up ₂ /...(4) and in the second case - / U ₁₁ / & / (e ^ + U_ _{/ J} ) k + U ₂ / ·. · (5X where β _χ1 - Hall voltage of the first Giver,

^U p1 ^f U ₂ - non-equivalent potential voltages of the first and second encoder,

B-magnetic induction to be measured,

k /] - transformation coefficient of the second encoder (k = & .B) mean"

If you add these two voltages together, you get ao a total voltage, the mean value of which is only the Hall voltage proportional and from the non-equivalent potential voltages of the encoder

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In cascade connection under the condition that / β _χ1 / x ^ / U - / and / e _x2 / = / (θ _χ1 + ü _p1 ) k /> / ü _p2 / 1st,
where ep "* Hall voltage of the second encoder 1st, independent 1st» According to the rule for algebraic operations with absolute values

* 4 »

under the condition that

^θ χ2 ^{/ </} V / ^s / ^θ χ1 / ^ ^U p1 / «n * / ^θ χ2 ^/ ^ ^{/ U} p2 ^{7 lst} »

becomes the mean of the total stress of the sum of the two called signals to be proportional to the Hall voltage · For three we get different cases

/ U'j / / * T / 2 + / U ¹ J ₁ / = / (e _x1 - ¹ W ^k - ^ϋ υ2 / ⁺ ' 2
k + / U _p1 / k - / ° _D2 / ♦ / 2 / Uf V + / Uff / = / (< 2
ϊ _χ1 - Up ₁ ) k - "na / ⁺ / (V ₁ * ' 2 - / e _x1 A ₊ , 0J _p1 / k ₊ A 2 ./u-V = / ( 2
x1 ~ pi " ^u _d2 / ⁺ -" -χι ^ r q _Λ / k + / c 2 '(Vi + u _o1 ) k ₊ u _D / OTp ₂ / = U _c1 k (6), ¹ ^ * ^{+ ü} r> ₂ / = J2 / = IT Jc + U _ρ (ί5 pi J) d
} k + U λ / ss J / -

In connection with this, under the condition that Ze ₁ / U ₁ / and / β _χ2 /> / U ₂ /, the absolute values of the output voltages of the first encoder are to be subtracted from one another and the absolute values of the output voltages of the »second encoder to be added to one another , with the condition that / β _χ1

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and / β _χ ο / ^ / Up / 1st to add the absolute values of the output voltages of the first encoder to each other and to subtract the absolute values of the output voltages of the second encoder from each other, under the condition that / θ _χ ,, / <VU ^ / and / θ _χ2 / K. / ^U p2 / ^is * » ^The absolute values of the output voltages of the first encoder and the absolute values of the output voltages of the second encoder must be subtracted from each other ©

When the Hall sensor is supplied with an alternating current of constant frequency, all of the above applies to the instantaneous values of currents and voltages Electrode changes by 180 ° »If in the first position the output voltage of the transmitter is equal to U ₁ = (Ε _χ - 7) sln *) * t ... (9) 1st, it is in the second position Ug = (S _x + V) sin6 ^ t ··· equal, where Ε _χ and U maximum values of the Hall and non-equivalent potential voltage,
Uq - angular frequency of the supply current
mean·

The mean value of the absolute level of these signals is only proportional to the Hall voltage _{at Ε χ} ^ "V _15.

In the case of a cascade connection of the Hall sensors of the above-mentioned type, the output voltage of the cascade connection is U ₁ =: (Ε _χ1 - 7 _p1 ) k sin ^ ο t - Vp ₂ sin iJ ot ... ( 11),

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in the second - U ₁₁ = (Ε _χ1 + V ₂ ) k sin & _Q t + V ₂ sinii _o t ... (i2),

where E _x ^ i Ε _χ2 , V ₁ , V ₂ - maximum values of the Hall and the non-equipotential voltage of the first and second encoder are ^e * 2 »C ^E x1 ± ^V _P 1 ^} k sin 6) _o t = E _x2 ) _o t.

The mean value of the absolute level of these signals is only proportional to the Hall voltage _{at E x} ^ V _p1 and E ₂₂ ^ "V _{2 *}

When the Sebers 1 is fed via each pair of the opposite electrodes (2-3 and 4-5) with alternating currents equal in magnitude and different in frequency, it follows from the above that the voltage taken off at one pair of the opposite electrodes is equal U ₁ a (E _x - V) sin6J ₁ t + V'sin6> ₂ t ... (15)

and the voltage drawn across the other pair of the opposing electrodes is equal to

U ₂ β (E _x + V_) sin 6) ₂ t + 7 "SIn ^ ₁ t ... (14)

istι where

V 'and V * ^# -yetr ^ ge of the voltage dropping at the encoder, at each pair of the opposite electrodes for currents with an angular frequency of 6) ₁ and d) ₂ are a frequency selection of these voltages (the first according to the frequency of ( Jb and α ^θ1? Second after the frequency of ^ ₂ )

1
as well as a subsequent rectification allow it, after

Average value of the absolute level of the two transformed signals to assess _{the true value of the Hall voltage at E x ^ V}

above is the one pair of the opposite

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- The voltage taken from 15 electrodes of the second Hall sensor is the same.

U ₁ = (E _x1 - V _p1 ) k sin 6 ^ ₁ t ~ V _p2 sin αλ, ΐ + V ₂ sin cd ^ i ... (15) and the voltage taken from the other pair of opposite electrodes of the second Hall sensor is the same

V _p1 ) k sin 6O ₂ t + V _p2 sin dc> ₂ t + V "slnC ^ t ... (16), where V ₂ and V ₂ * - amounts of the falling over the second encoder, at each pair of the opposite Electrodes of the second

Yes

In the case of currents with an angular frequency of i *) ₂ and ^ J _{1 the} voltage to be taken off are «Here the output voltages U,. and U ₂ from the first and second pair of opposing electrodes of the first Hall sensor, where

U ₁ = (E _x1 - V _p1 ) sin60 ₁ t + VjJ sin ^ ₂ t ... (17),

U ₂ = (E _x1 + V _p1 ) sin <0 ₂ t + V ₁ 'sin 6 ^ t ... (18)

are selected according to the frequency C ^ ₁ or (£ ₂ and feed the opposing pairs of electrodes of the second Hall sensor, where V ₁ and V ₂ * - Betr-Hgeder falling on the first Hall sensor, on each pair of the opposing electrodes of the first sensor for currents with an angular frequency of Ct) ₂ and ΰύ _{1 the} voltage to be decreased is

The frequency selection of the output voltages of the second transmitter (the first after the frequency Cm ₁ and the second after the frequency G ^ ₂ ) as well as the subsequent rectification make it possible to use the mean value of the absolute level of the two converted signals above the true value of the SHK of the Hall transmitter in cascade connection under the condition that E ^ ₁ ^ V ₁ and

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so by taking the output signals from the two pairs of the opposite electrodes of the Hall sensor and each Hall sensor with their cascade connection according to the time or frequency separates, one can see the influence of the non-equivalent potential voltage completely exclude the emf of a sender and the emf of the Hall sender in cascade connection

One of the devices for realizing the method of eliminating the influence of non-equipotential voltage

on the Hall voltage contains a Hall sensor I (Flg · 2a) two opposite pairs with a supply source 6 and a Hall voltage indicator 7 of the Hall sensor I via the switch 8 coupled electrodes 2-3 and 4-5

The changeover switch 8 is used to switch on the Electrode pairs 2-3 and 4-5 of Hall sensor I to the supply source 6 or the Hall voltage indicator 7 of the Hall sensor I are provided · Various contact and contactless switching devices: mechanical, electromechanical, electronic etc. in question

. So / are for example in Fig. 2b and 2c two variants of the

Contact circuit in an electromechanical switch δ from Relay type reproduced, the two pairs I-II and III-IV Contains changeover contacts, the movable contacts 9, the pair I-II with the supply source 6, the movable contacts 11.12 of the pair III-IV with the Hall voltage indicator

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7 of the giver and any immobile noioaal closed contact 17, 14, 15 »16 of the two pairs I-II and IH-IV with the corresponding immobile normally open contact 17 »18, 19§ 20 of the same pairs and in turn with one of the corresponding Electrodes 2-5 »4-5 of the Hall sensor I are coupled, with the Control winding 21 of relay 8 is connected to a control generator 22 is,

The in ü'lg. Variant illustrated 2b aer contact circuit "in which the normally closed stationary contact 13 and the normally open stationary contact 17 of the changeover contact is I ζ overtake with the normally open contact 19

of the changeover contact III to a normally closed contact 16 of the changeover contact IV and the immovable contacts 14, 18 of the switchover contact II with the normally open contact 20 of the switchover contact jlV and the normally closed contact 15 of the changeover contact III are coupled, allows

when switching the electrodes (2-3, 4-5) of the sender I that To invert the output signal of the universal encoder

The variant of the contact circuit shown in FIG. 2? 1 and II with the immovable contacts 15 »19 and 16, 20 of the changeover contacts III and IV cross-connected does not perform any operation to invert the output

output voltage of the encoder I when switching its electrodes (2-3, 4-5) from

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EXne another variant of the device for implementing the method for eliminating the influence of the non-equipotential voltage on the Hall voltage can be connected to the Hall sensor I (Fig. 3) with two pairs of opposing electrodes 2-3 and 4-5 alternating current sources 23 and 24 with a frequency of CÖ and 2n tb, where η - is an integer, and two phase-sensitive rectifiers 25, 26, the outputs of which are coupled to a summator 27 connected to a Hall voltage indicator 28 of the Hall sensor.

The phase-sensitive GIe teaches 25 and 26 are for Frequency selective from on the two pairs of the opposite one Electrodes (2-31 4-5) of the encoder I signals to be picked up and their rectification is provided, in order to follow the mean value obtained by means of the summator 27 of the absolute level of the two transformed signals to judge the true value of the Hall voltage

One of the devices for implementing the method for eliminating the influence of the non-equipotential voltage on the EMF of the Hall sensors in cascade connection contains a first Hall sensor I (Flg. 4) with two pairs of opposing electrodes (2-3, 4-5), which over the Changeover switch 8 are connected to the supply source 6 and a supply voltage shaper 29 for a second Hall sensor 3O ₁ connected to the supply source 6, a second Hall sensor 3 ° ^m ^ two pairs of the opposite one, with the supply voltage shaper 29 and the

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Hall voltage indicator 7 of the second Hall sensor 30 over an additional switch 31 coupled electrodes (2'-3 \ 4 * '- 5').

Another variant of the device for implementing the method for eliminating the influence of the Uichtaquipotentialspannung on the EMF of the Hall sensors In cascade connection snthaltzwel to an additional supply voltage shaper 32 for the second Hall sensor 3 ° (Fig. 5) and to the first Hall sensor I with two pairs of opposite Electrodes (2-3, 4-5) connected alternating current sources 23 and 24 with a frequency of tD and 2n t *> , two frequency selektftJBan 33 »34, which are connected to the additional supply voltage shaper 32 for the second Hall sensor 30, whose outputs to the second Hall sensor with two pairs of opposing electrodes (2 * - 3 'and 4 * - 5 *) are connected, and two phase-sensitive rectifiers 25, 26, the outputs of which with the summator connected to the Hall voltage terminal 28 of the second Hall sensor 30 and inputs with the corresponding outputs of the supply sources 23, 24 and the additional supply voltage shaper 32 of the second Hall encoder 30 are connected. The frequency selectors 33 and. 34 are frequency selective, from on the two pairs

The signals received from the opposite electrodes (2-3 and 4-5) of the transmitter I are provided ^# ) des

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second encoder 30 picked up signals and their rectification provided, in addition to the mean value obtained by means of the summator 27, of the absolute level of the two converted Signals about the true value of the EMF of the Hall sensors in a Λ-acade connection judge

The device works as follows »When the Hall sensor I is supplied with direct current I over

the pair of opposite ones in the initial state of the switch 8 (s * Fig * 2b) with the supply source 6 via the contacts 9, 13 and 10, 14 connected electrodes 2-5 and at the Einwir ** k'ong arise on these of a constant magnetic induction a Hall voltage e_ at the other pair of electrodes 4-5. and a non-equipotential voltage U · Let us assume that the polar it at ext of the latter coincide

Jk. A-

clocks 11, 15 and 12, 16 with electrodes 4-5 of encoder I. connected and a DC ammeter representing Hall voltage ^ - indicator 7 of encoder I measures the output voltage IJL = e „+ U

I JL JP

When the contacts of the relay 8 are switched over under the effect of a control signal U from the control generator 22 the electrodes 4-5 of the Hall sensor I via the contacts 9, 17

and 10, 13 to the supply source 6 and the electrodes 2-5 to the Hall voltage indicator 7 of sender 1 switched on * As a result of Not reversibility of the encoder I with respect to the Hall voltage e ^ and its reversibility with respect to the non-equipotential

Λ A

voltage U is the output voltage of the sensor I taken from the electrodes 2-3 equal to TJ __ ~ β _χ + U, as in the case of the contact circuit

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of the relay 8 (see Fig. 2b) an inversion of the voltage U _{2 is} assumed, the Hall voltage indicator 7 of the transmitter I measures the output voltage U ₂ a β _χ - U ·

If the voltage U of the control generator 22 changes with a certain frequency, the output voltage U ^ of the transmitter I picked up at the two pairs of electrodes 2-3 and 4-5 is shown in FIG. 6a have the course shown. If the voltage U _{2 is} inverted, the sum output signal U ^ has an _{equal part proportional to the Hall voltage θ χ} and one proportional to the higher equipotential voltage U

Change share on. If the voltage U _{2 is} not inverted, the contact circuit of the relay 8 according to FIG. 2c is used. The total output signal Ug of the transmitter I has an _{alternating component proportional to the Hall voltage e x} and a direct component proportional to the true equipotential voltage U. Depending on the application of the respective contact circuit of the relay 8, the indicator 7 must either be a direct current device (in the case of an inversion of the voltage U ₂ ) or an alternating current device (in the case of no inversion of the voltage U ₂ ).

When the Hall sender I is supplied with an alternating current

fixed frequency from the supply source 6 (Fig. 2a) represents the total output voltage U ^ in the switching mode of the electrodes 2-3 and 4-5 represent an amplitude-modulated signal (Fig. 6b) on the basis of the above and the equation Useful information and separated by means of indicator 7 for medium

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values (in Fig. 6b the voltage U ^ at the output of the amplitude detector) can be measured «

The pointer deviation in the Hall voltage indicator 7 of the Hall sensor by an angle ^ l is aleo in the cases under consideration the mean value of the absolute level of the output signals picked up at each pair of the opposing electrodes, ie. the size of the Hall voltage e_ _f proportional and independent of the Uichtaqliipotential voltage U

When cascading the Hall sensor (Fig. 4) is the Mode of operation of the first Hall sensor I of the mode of operation described above, fed by the current source 6 via the changeover switch 8 of a Hall sensor with the same switch is similar · The one on the pairs of opposing electrodes 2-3 and 4-5 output signal Urf * taken from Hall sender I is used for Supply of the second Hall sensor 3 ° via the additional switchover

"A Λ

ter 311 where the work of the latter is that of the giver I. with the toggle switch 8 is similar to «UIe toggle switches 8 and 31 controlled by the commutation generator 22 The indicator 7 measures the output voltage of the second Hall sensor 30 *

When the first Hall sensor A is supplied with a direct current I and when the magnetic induction acts, the output signal U <. of the first Hall sensor 1 in the case of an inversion of the output voltage of the first Hall sensor % equals TJ ^ ₁ S e _x1 + U _p1 . ·. · (19)

and with no inversion of the output voltage of the first Hall sender 1 when switching over the electrodes of the Hall sender

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¹¹ ^ I = Vl ^{1 θ} χ1 - ⁽²⁰⁾

In the first case, the second Hall sensor 30 is generated by the direct component of the sum output voltage U ^,. the first Hall sensor 1 and in the second case by the AC component of the sum output voltage UV, ^- the first Hall sensor 1 "the ^θ of the Hall voltage χ1 ^ ^{it e2 s} * ^s Geyer 1 proportional slnd _t fed" The output voltage \ 5 <ο the second Hall sensor 30 is equal to Ug- ₂ = ke _x / j ± U ₂ in the case of an inversion of the output saving of the second Hall sensor 30 and equal to U ^ ₂ = U ₂ + ke _x ^ in the case of no inversion of the output voltage of the second Hall sensor 30 when switching Its electrodes · In the first case, the sum output signal Vg _{2 has a GlelchantBil} proportional to the Hall voltage β χ2 = ^ χΊ ^ - ^es second transmitter JO and an alternating component proportional to the no-voltage potential voltage U _{2 of} the second transmitter 30. In the second case, the sum output signal U ^ g _{2 has} a Y / echsel component proportional to the Hall voltage θ _{χ2 of} the second encoder 30 and an _{equal component proportional to the light equipotential voltage U 2 of} the second transmitter 3Q depending on the application of the respective contact circuit oe in the additional switch 31, the indicator 7 must be a direct current device (in the event that the voltage of the second transmitter 30 is inverted when the contacts of the additional changeover switch 31 are changed) or an AC device (in the event that the voltage of the second transmitter 30 is not inverted when the contacts of the additional changeover switch are changed over) 31) to be

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When supplying encoder 1 with an alternating current fixed frequency from the source 6 (Fig. 4) represents the total output voltage of the second Hall sensor JO in the switching mode of the Electrodes of Hall sensors 1, 30 based on what has been said above and equations (9, 10) an amplitude-modulated signal represents whose groove ζ information is deposited and through the indicator 7 can be measured for mean values *

The pointer deviation of the Hall voltage indicator 7 of the Hall sensors 1 and 350 in cascade connection by an angle O ^ is therefore the mean value of the absolute level of the signals picked up at the spring pair of the opposing electrodes of the second Hall sensor 30, i.e. the Hall voltage ^e x2 »P ^r ° P ⁰ⁱ * 3L ^01ia l and independent of the non-equipotential voltages Up ₁ and U ₂

When feeding the Hall sensor 1 from the two alternating current sources 23 and 24, the frequencies of which are even multiples differ, and under the action of a constant magnetic induction arise at each pair of the opposite Electrodes 2-3 and 4-5 of the encoder 1 voltages IL and Ug, which each have two components of different frequencies: the '.:.: -

one component is due to the presence of the Hall voltage e_- and the non-equipotential voltage U and the other due to a voltage drop across the encoder 1 as a result of the passage of a supply current. The electrodes 2-3 of the Hall sensor are connected to the power source 23 of the frequency u) and the electrodes

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4-5 mi * ^of power source 24 of frequency 2n & 3 connected. The voltage IL picked up at the electrodes 2-3 is applied to the input of the phase-sensitive rectifier 25 the voltage of the current source 23 is used as its reference voltage. Thanks to the selectivity of the phase-sensitive rectifiers 25 and 26, the values of the DC voltages IU and Uk at their outputs do not depend on the voltage drop across the encoder 1 as a result of the passage of the supply currents I ^ and ig is a non-reversible and with respect to the non-equipotential voltage U a reversible element, the size of the direct component of the voltage at the output of the phase-sensitive rectifier 25 is proportional to a sum of the Hall voltage e_ and the Hlchtäqulpotentlalspannung U and at the output of the phase-sensitive rectifier 26 their difference is proportional. Then, if the transfer factors of the two phase-sensitive rectifiers are equal, the voltage U, - is at the output of the summator 2? proportional to the Hall voltage β _χ and independent of the non-equipotential voltage The indicator 28 registers the true value of the Hall voltage

For a more complete selection of the output signals from the encoder 1, you can choose between the phase-sensitive rectifiers

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25 and 26 and the pairs of opposing electrodes 2-3 or 4-5 of the encoder 1 selective amplifier (not in Fig. 3

shown) are switched

With the cascade connection of the two Hall sensors (Fig. 5), if the first Hall sensor 1 is fed by the two alternating current sources 23 and 24, the frequencies of which differ by an even multiple, voltages arise at each pair of the opposing electrodes, each having two different components Have frequency »The independent of the supply currents I ^ and i ₂ components of each pair of electrodes 2-3, 4-5 of the transmitter 1 are separated by the frequency selectors 33 * 34 and get into the additional supply voltage shaper 32 for the second transmitter 3 ° · the. Work of the part of the device, which is composed of the second Hall sensor 30 "which is fed by the aforementioned supply voltage shaper 32 by two currents" whose frequencies differ by an even multiple, the phase-sensitive rectifiers 25, 26, the summator 27, does not differ in any way of the above-described work of the device (according to FIG. 3) with a Hall sensor 1. The voltage at the output of the summator 27 is the Hall voltage β _χ2 a. _{it is} proportional to the second encoder and independent of the non-equipotential voltages U ^ and U _{2 of} the encoder · The indicator 28 registers the true value of the Hall voltage of the second encoder »

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The present invention thus allows it in comparison to the well-known, the influence of the non-equipotential voltage to completely exclude the EMF of a Hall sensor and the EMF of the Hall sensor in cascade connection, which is the possibility there is to reduce the measurement or registration speed by leaps and bounds,

to increase the accuracy and sensitivity of the devices with the Hall sensors, absolute value of magnetic induction to determine the monitoring process in the given volume of the room to automate the hall sensors in digital devices

to use successfully

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Claims (4)

- 28 PATENT CLAIMS Ί.) Procedure for eliminating the influence of the equipotential voltage on dia Hall voltage that on the evaluation the irreversibility of the Hall sensor builds up, thereby characterized in that the transmitter is fed alternately via one of the two pairs of opposing electrodes and the output signal to the other pair of electrodes and according to the mean value of the absolute level of at least two successive output signals via the the true value of the Hall voltage is judged 2. Method of eliminating the influence of non-equipotential voltage on the Hall voltage, which is based on the evaluation of the irreversibility of the Hall sensor, characterized in that the sensor over each pair of opposing electrodes is fed by currents which are equal in magnitude and different in frequency with output signals at the same electrode pairs which are then selected and rectified according to the frequency and then according to the mean value of the absolute level of the two converted signals is judged via the true value of the Hall voltage 3. Facility for implementing the method according to Ans * Claim 1, in which one pair of the opposing electrodes (2, 2) of the Hall sensor (1) with the supply source (6) and the other (4,5) coupled to a Hall voltage indicator (7) 409883/0703 233308Q is, characterized in that it contains a changeover switch (8) with the help of which said Pairs of electrodes (2, 3 and 4, 5) alternately on the half-voltage indicator or connected to the supply source 4. Device according to claim 3t characterized that the switch (8) for the Hall electrodes as an electromechanical switch with at least two pairs (I, II and III, IV) changeover contacts is carried out, with the movable contacts (9, 10) of one pair (I, II) with the supply source (6), the movable contacts (11, 12) of the other pair (III, IV) with the EallspannungsIndikator (7) and each immobile normally closed contact (15i 17 »14-, 18) of the elnea pair (I, II) with the corresponding one immobile normally open contact (19 »16, 20, 15) of the other Pair (III, IV) and in turn connected to one of the corresponding electrodes (2, 3, 4, 5) of the encoder (1), wherein the Steueratromkrets (21) of the switch (8) to a Stauer generator (22) is coupled. 5 _# Device for implementing the method according to claim 2, in which one pair of the opposing electrodes (2, 3) of the Hall sensor (1) is connected to the supply source (6), marked leans through one to the other pair of opposing electrodes (4, 5) connected additional supply source (24), its frequency different from the frequency of the above mentioned source (23) differs by an even multiple, two phase-sensitive 4 09883/0703 Rectifiers (25 »26), the inputs of which correspond to the corresponding Pair the opposing electrodes (2, 3 and 4-, 5) and the outputs of these rectifiers (25 »26) to the input a summator (27) connected to a Hall voltage indicator (28) are coupled. 6 «Device according to claim 3», characterized in that it has a Hall sensor (30) with two pairs (2 * - 3 ^# i 4 * - 5 *) opposing electrodes, an additional changeover switch (31) and one to the supply source (6) via the changeover switch (8) for the electrodes of the first Hall sensor (1) contains the supply voltage shaper (29) for the second Hall sensor, while the output of this shaper (29) is connected to the additional changeover switch (31) whose help the mentioned pairs of the opposing electrodes of the second Hall sensor (30) are alternately connected to the supply voltage shaper (29) or to the Hall voltage indicator (7) coupled to the outputs of the additional changeover switch (31). 7 · Device according to claim 5 »characterized in that it contains a second Hall sensor (30) with two pairs of opposite electrodes (2 * - 3 *» * «■" - 5 ") and an additional supply voltage shaper (32) for this sensor, where each pair of opposing electrodes (2 * - 3 '» ² J - * - 5 ^# ) soa. the corresponding phase-sensitive rectifier (25, 26) mentioned and to the corresponding one 409883/0703 The output of the additional supply voltage regulator (32) is connected is, in which the one inputs via corresponding frequency selectors (33 »JH) with the pairs of the opposite Electrodes (2-3 »4-5) of the first Hall sensor (1) and the other inputs of this additional pormer (32) to the named. Supply sources (23, 24) are switched 409883/0703