DE1946530C3 - Hall generator for analog representation of the nth power of a variable - Google Patents

Description

1 2

The turn hides a hall generator, the shape of which. 3 an all-guide example using a thermal

Output voltage: itself with the «th power of the disruptive compensation of the temperature curve,

magnetic induction changes. K i g. 4 a guiding example with an additional

For the analog representation of a pot / function, helical lallelcment and a magnetoresistive line are

already chain connections of four-pole allelec- 5 ment / ur Lincaritätskorrekiur,

th have been used whose Λη / alil corresponds to the desired 1 ^; i g. 5 an exemplary embodiment with two magneto-

Lxponaiten corresponds. Here are all Hall-resistive elements / for a device correction and

elements in a magnetic field, the magnetic In- F i g. '> an aiis fulmmg hypothesis with just inside

production represents the changeable. Pas first element gnetoiesistiven element / ur Lmearity correction.

is increased with a constant input current. 1 shows a 1allgenerator / ur Darstdlimgemer

Schlaizt while at the output terminals of the last quadratic function. He commits from a first

Elements the load. d. H. A "" measuring instrument is applied to the Hall element 2 with input terminals 21, 21

Output terminals of each previous Hallelemen- a power source are connected, and one

These are connected to the input terminals of the / wide Hall element 3 via amplifiers

the following llallelementcs \ investigate. The Aus 15 of the middle section of the first Hall element, on

gnnisspnnmma of the previous Hall element is usually attached to the output terminals

thus in each case proportional to the input current of the subsequent ones.

following Ha.Vi.ements. It is true that the end of the extension

the output voltage of the last Hall element actual conclusion 31 is with your on the opposite side

mainly with the / Men Poten / the magnetic inductor 20 of the first Hall element attached terminal 22

tion fluctuates if the one Hall element in the egg is opposed to an external one;

working in the area of nearness and dogging in their characteristics. The primary neck tension 17 / ,. those in the first

are largely identical. Hall element at a Spti> e> tiom /, and the magnetic

However, this circuit has different unavoidable induction 11 is generated, so it delivers one

borrowed disadvantages. The material properties differ- 25 stream in circuit 4L as the input stream for the

11er shark elements are never exactly the same, so that the characteristic / range Hall element 3 is used.

lines do not match. In addition, the output terminals 32. 32 of the / wide range fluctuate

also the understanding; properties. whereby further ments are connected to a load 5 and are used for

There are deviations from ideal behavior. Also the decrease in the secondary I lall tension I 7 /., That of

magnetic field strength ί, ηι place Jcr individual separated 30 a stream / .. ir ,: / wide HallclemeiH 3 in association with

ten common elements is not always calibrated. and that of the magnetic induction B is generated,

intermediate amplifiers cost money. The output terminal 22 of the first Hall element

The object of the invention is to overcome these disadvantages and to avoid the output terminals 32, 32 of the second Hall and a shark generator available / u elements can be designed as simple projections ! en, the one that largely comes close to the ideal. However, are they forked as in the figure. so lets Characteristic curve shows. adjust the residual reverberation voltage comfortably, since the

To solve this problem, the terminal resistor according to the invention is middle tier potentiometer 6

Hall generator for analog representation of the / Men power can be provided.

a variable, based on a chain The output voltage characteristic of the in F i g. 1 Circuit of the type described above, characterized by the 40 illustrated electrical generator, can be drawn as follows, that every following reverb in the chain gives:

element as a one-sided extension of the mean Ab- Are the I lall constant ·: a Hall element with λ ', intersection of the preceding Flallel element formed the primary current with /, the magnetic induction is with B and that at the end of the extension of this Ab- and the coefficient of Residual reverberation voltage with λ "trimmed and drawn on the opposite side of the 45, mi generally applies to the terminal voltage 17 / of a hallcment arranged before the previous hall elements:
are connected to one another via an external resistance circuit. I // i (KB f A ") ... (D

The whole electrical generator therefore consists of a single plate, so that fluctuations in the material! 1 are largely eliminated by the properties and the indices 1 and 2 are differentiated, then for each magnetic induction at all points slightly the same applies - one of them:
can be kept in shape. The one with the previous one.

Arrangement of intermediate amplifiers fall '' Ί (A, ß ■ 'A ₁ ) ... U)

path. 55 VH ₁ I ₁ [K ₁ B - A ',) ... (J)

Expedient refinements of the invention relate to a further linearity correction by counter-coupling the internal resistance of the second Hallelcment by means of magnetoresistive elements and a with r // _a and the external resistance in the circuit 41 compensation of the temperature response. denoted by R ₁ , the following applies:

Some embodiments of the invention are shown in FIG

described below with reference to the drawing. Here- '2'"i / ( ^f "! ' R ₁ ) ... (4)
in is

F i g. 1 is a schematic representation of an invention from equations (2), (3) and (4) one obtains:

according to this Hall generator with quadratic characteristic y ^ ■ <χ β -K'HA'ß FA ") '

line, 65 ² Λ //, '.;, r \ ^{2 2} ' (5)

F i g. 2 shows an embodiment in which the " 2 · · ·

output voltage is the «th power of the magnetic In- Since the coefficients A", and K ' _{2 are} the residual reverberation span

production by appropriately setting the potentiometer 6

Disappearance results in the ,,, I Hen Hallelement ™ ^^^ Z

" ¹ ^ - ^hlldtlldl: j ¹ , ', ^ _n nallelemen. Evoke, and thereby .m ver

17 /, /, B ^ K ₁ K ₁ UH ₁ - A \) - - ■ I'D ⁽ _{cin m} ; _td , _m magnetic field on,

Dami. it is shown that the output voltage I U ₁ 5 voltage of the /, - th "^« ™ ^ _s ". _{! eM Yhl] U}

_licr m I- 'i g. 1 arrangement shown is a quadratic An d, e output I mm 1 - Π! d- _

, ical characteristic depending on the magnet, - elements 12, st emc L, s 5. ^^

see induction B exhibits as it was aimed at. ker oder em G! e, chstrmimrst. ^ jJ ¹ ; , _Uis , _2an ,,,.

I, _a 2 shows an application of the principle that the /, - th Hall voltage I // ". we eh de |

. _u , f the generation of an output voltage. Which is in the tension of the whole arrangement, this one

', en power of magnetic induction B ab- ™ ^^^^ _dcs third to / Men

'IS first Ha.lelemcnt 2 is, vv.eaer mil input 1 iallelements with K ^^^^ l ^ t

_k , emmen21.21versehen, andenene ", eEnerg, equelW of the different new Ha! element " a H "« · ■

l, _c ,, The second hallcment 3 is just like in .5 and the external contradiction andt of the unzcincn. _h _

γ f .. '1 by unilaterally lengthening »the middle final copper losses) with« .. «· ■■■ ¹ J""

J, mtts of the first üalieleme ^ originated. Oa the r.et. - follows from equations (1) b., (6)

both input terminals 22 and 31 de, / wide Hall- R> - [KK K „) irll, ■■ /?.! ·

■:, - Pienis connected via an external circuit 41 ''"'' _ '' J -J ^ '" _{ß |)} ;

.-J. becomes the v <in the first Hallelemciii as a result of the Pn- 20 «'1 ^ '' ₍ 7)

i; -, ar> iroms ι, in conjunction with the magnetic induction ^;;

ti.in Il he / eiiiiiiiiiiie primary general tension as the source for, _t . _ltvic | _n | jch

j ,, 1, "angsstrom of the second Hall element 3 starts ^^ f ^" - ^^ iÄ auction_ _fl .

lllit / l.

There, third Hall element 7 is due to one-sided distortion π I ^ the Hall voltage eier uhl.ch ^ n work ^ ton. H

, change of the middle section of the first ».all- kannthch with the tempera u η mmt m ^ ^

elements 3 was created. This is, so now / t the basic compensation of the Te r .1 ^ n ^ _{1 before} .

_flli the third Hall element. Since the at the end of the \ er Jen. around the zur Darsu h ng .k I oiu _{/ u}

,: _{Terminal 7. located in} , cr..ng and the dr offset linear ,, «, ckr unzdncn» ^ _{d; u} .

lan, 'aung opposite output terminals ^ des, o reach In 1 · · ■''-' ^ ^ _-1 J, _ator / j _ücm äß

"." Th Hall elements placed via an outer circle 42. It consists of the ^ι1 ^^ ^Γ '; _{gate 12}

, connected to each other, cruibt d.e secondary reverb E i g. 2 and a thermistor 12 Π Tl erm s.

"Well, Γ ... the one in the second Hall element through the harbors in series m" the ^^^ ² ,! ^^

S r..m / Punier the lintluß of the primary I lallspan- Hall elements 2 and the voltage source I ^

π _and VII, generate w, rd, in conjunction with the magnetic pera. urcoefficien, P , st so chosen that it dn Vc, K

fold'einc has tertiary Hall voltage I / Z _n at the output P c - ". if ^ Χ ,, ί"! , Hall lemen.e

klen..nen the third hall element. temperature coefficient c J aufv u ^u ^ J |

The v, th Hall element 8 represents vv. Each a one-sided are present, c is the basis of the naturM.ncn u _b

Extension of the middle section of the third rithmen,.,. ,, ._ " _{crEJbt s} j _c h aus

Hallelcmen.s 7. The at the end of the I lallelements 8 ₄ "The effectiveness ^ d.cs" M ^ mc rg ^ t

any terminal 81 and the opposite terminal of the following Bctra.h ^ f. ^ enen M

Ausßannsklemme 72 of the third Hall element are about gate with square Kenn 'me. Un he ^B

an outer circle 43 connected so that the tertiary supply depends on the temperature! ^ * d, r Hall constant

Hal voltage Ι7 / _π , which applies in the third Hall element by:

a current /, due to the influence of the secondary 45 Γ //, ι, RK ₁ C ' ^T ... < ⁸ >

Hall voltage VH _{1 is} generated when the magnet ^. ^ ^ ΒΚ, ι- ^lT · ■ ■ ' ⁹ >

field B is available to the fourth hallcment- ^2;

^ cii ^ fifth Hall element 9 and the rest of this results, taking into account equation

Hall elements up to (n l) -tcn Hall element IO <= mt '50 (4):

as above by unilaterally extending the middle _{r //} ^ ^. _e 1 .r. ^ ₁ . A ₂ · B ¹ I (R ₂ V rH ») ■ ■ ■ U ^u )

_e ^A r :: 'n. SÄÄTisr ^ s ***** «*« * h. »Γ « ü ^ sr · * ■ - ■

loaned output terminals 91 to 101 of the various Potenxfunkt.on the /, - th order supplies.

Components and those on the opposite side 55., _K K _n ) B ⁿ e "" ^T l

of the respective base element located output- '"> ,, IA ₁ A _{2 n} - ^. ^

terminals 82, etc., are resisted via external ^ '»2; 2;, - '/? ") ... (M)

adhered circles 44 ... 4 ", as connected above, so that < ^r "'"···

the Hall voltages VH ₁ ... 17 / ,,, which emerges from the respective equation, takes di

Basic elements serve to determine the input current for the 60 As from the above table ¹ ^ ,, ^fc _{ncr; tors with de}

märstroni r, increases just to the extent that is required. about the decrease in the initial span-Ii u ng 17 / »to balance. This is how you get the desired crap of the temperature curve reached.

It is also possible to connect a thermistor to the external circuit of every Hallelcir.cnts, the temperature coefficient of which runs according to the function / 'c * ⁷ '. In general, however, it will be easier to use a single thermistor with the mentioned temperature dependency in the input circuit.

As can be seen from the above equations, the value of the output voltage I // "depends heavily on the internal resistances RIL ... rll" of the individual Iallclcmcntc. Since the internal resistance of a Hall element increases with the magnetic induction, the desired linearity of the output voltage is lost. It is therefore advisable to introduce negative feedback. F i g. 4 shows a circuit for this.

For the sake of simplicity, FIG. 4 again a Hall generator D with a quadratic characteristic curve, which therefore consists of two Hall sensors 2 and 3, is shown. However, the negative feedback shown can also be used just as well for a Hall generator with any number of Hall elements.

To compensate for the non-linear behavior of the individual elements of the Hall generator, a four-pole Hall element 13 is connected to the external circuit 41, which transmits the primary Hall voltage 17 /, of the first Hall element 2 to the second Hall element 3, so that an input current i. Flows there. The current “flows through the Hall element 13 / between the terminals 131, 131 as input current. The output terminals of the same 132, 132 are connected to the input terminals 141, 141 of a magnetic-resistive element 14.

It is necessary that this magnetorcsistivc element is in the same magnetic field B as the actual Hallger.erator D. The compensating Hall element 13 can also be accommodated in the same magnetic field, but for a defined compensation effect it is preferable to arrange the Hall element 13 in a magnetic field with a constant magnetic flux density.

If the magnetic induction B. which excites the Hall generator D , increases, the internal resistance of the Magnelorcsistiven element 14, which is in the same magnetic field, increases. As a result, the input resistance of the compensation element 13, ie the internal resistance with respect to the current ι, becomes negative, ie it decreases.

So one hand, the current value U in the second Hall element 3 with increasing magnetic induction on, and the internal resistance of this Hallebments rises, on the other hand, the internal resistance of the compensating element reduces 13. Thereby, the desired approximation of the output voltage l7 / ₂ is reached at the ideal value.

It would be most effective if a compensation element 13 with an associated magnetorcsistivcm element 14 were inserted into the circuit of each Hallelemer.tcs. With a suitable choice of the characteristic values, however, the significantly cheaper connection just described can be implemented solely in the last circuit. In any case, the negative resistance Ar (B) of the compensating Hall element 13 should be chosen so that it just compensates for the increase in the internal resistance ArH (B) of the compensated part (i.e. of a Hall element or all but the first), i.e. Ii.

l; 7 / («) Ir (fl) 0.

The fluctuations in resistance of the first I IaII-cleincnts with magnetic induction basically influence the primary current »,, but this can practically ignored when a constant current source is used. For the

In the first reverberation, therefore, no compensation device is required to be provided.

Instead of the in FIG. 3, other solutions are also possible. Two of these are described below with reference to FIGS. 5 and (1 discussed. Here, too, for the sake of simplicity, Hall effects are shown with a square curve.

In Fig. 5 and 6 is connected to the output terminals 32, 32 of the universal generator D a gcgcngckoppcltcr amplifier

zo ker 15 connected, in its Gcgcnkopplungskrcis a magnetorcsistive device is located.

In the embodiment according to FIG. 5, two magnetoresistive elements 16 are connected in series between the output terminal of the amplifier 15 and the positive output terminal 32 of the Hall generator D. The two magnetic resistive elements 16 should be in the same magnetic field as the Hall generator D.

If the magnetic induction increases and thus the internal resistance of the Hall generator D increases, the internal resistance of the magnetic-resistive elements 16 also increases. Since the negative feedback voltage decreases as a result of the increased input voltage in the negative feedback circuit, the attenuation of the output voltage 17 / I occurring at the input of the amplifier is limited. On the other hand, the magnetic induction, and thus also the Inncnwidcrstand of Hallgencrators from D, so the Innenvvidcrstand magnetorcsistiven the elements 16 is reduced so the Gegcnkopplungsspannung increases, and the attenuation of the output voltage K // ₂ is giößcr.

Thus, the increase in the internal resistance of the Hall generator D with increasing magnetic flux density is compensated for by the lower attenuation of the output voltage, and vice versa. In this way the practically usable output voltage of the amplifier is linearized, that is to say in the present case that it becomes proportional to the ½ power of the magnetic induction.

It can also be a magnetoresistive element Ii are used, which according to FIG. 6 in the opposite Kopplungszvveig of the amplifier 15 from the amplifier output to the grounded output terminal 32 of the Hall generator is located. Such modifications of the counter coupling circuit are well known.

Claims (5)

Patent claims: 1. Hall generator for analog display of the dei / i-th power of a variable, consisting of: a chain connection of π in the same, the ver changeable magnetic field in the form of Hall elements, the first of which at its input clamp is connected to an energy source and the latter is connected to its output terminals Provides voltage that has the desired dependence on the magnetic induction characterized by you ti each I lallelcnicnt (3) following in the chain as unilateral Extension of the middle section of the sdrhergehiegen llallelcmcnts (2) is formed and that the one on the linden side of the extension of this section and on the one opposite it Side of the preceding Hallcicment arranged clamps (31, 22) over an outer Resistance circuit (41) are interconnected. 2. Hall generator according to claim 1, characterized in that a temperature-dependent resistor (12) is connected in series with the energy source (V) and the input terminals (21, 21) of the first Hall element (2) and according to the formula l> _e η > t depends on the temperature, where P is the temperature coefficient of resistance, e is the basis of the natural logarithms, η is the number of Hall elements contained in the Hall generator and e ' ^{r is} the temperature coefficient of each of these Hall cmcnte. 3. Hall generator according to claim 1, characterized in that temperature-dependent resistance stands with the Tcmpcraturkocffiz.ienten / '<■ ^{> r are connected} in series with the 1-input terminals of the first terminal and with the external resistances of the other terminals. 4. Hall generator according to one of the preceding Claims, characterized in that in one or more external resistance circuits (41) Compensation devices are located, each consisting of one of the input current of the respective Hallelemcnts durchfiossencn additional Hall element (13) exist at its output terminals (132, 132) a magnetoresistive element (14) is connected, which is in the same magnetic field how the reverb generator (D) is located. 5. Hall generator according to one of claims 1 to 3, characterized in that the output terminals (32, 32) of the η-th Hallelemcnt a gcgcngckoppclter amplifier (15) is connected is, in whose coupling circuit there is an odci several magnctorcsistivc elements (16) are in the same magnetic field as the Hallgeneratoi (D) are arranged. 1 sheet of drawings