WO1986007144A1 - Sensor arrangement - Google Patents

Sensor arrangement Download PDF

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Publication number
WO1986007144A1
WO1986007144A1 PCT/DE1986/000182 DE8600182W WO8607144A1 WO 1986007144 A1 WO1986007144 A1 WO 1986007144A1 DE 8600182 W DE8600182 W DE 8600182W WO 8607144 A1 WO8607144 A1 WO 8607144A1
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WO
WIPO (PCT)
Prior art keywords
coil
sensor arrangement
arrangement according
measuring
measurement
Prior art date
Application number
PCT/DE1986/000182
Other languages
German (de)
French (fr)
Inventor
Klaus Dobler
Hansjörg Hachtel
Karl Roll
Original Assignee
Robert Bosch Gmbh
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Publication date
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Publication of WO1986007144A1 publication Critical patent/WO1986007144A1/en

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/20—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature
    • G01D5/2006—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils
    • G01D5/202—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils by movable a non-ferromagnetic conductive element
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/20—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature
    • G01D5/2006—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils
    • G01D5/2013—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils by a movable ferromagnetic element, e.g. a core

Definitions

  • the invention is based on a sensor arrangement according to the type of the main claim.
  • the sensor consists of a measuring tube and a coil which is wound in one layer and uniformly on a core and is connected to a voltage divider or bridge circuit.
  • This results in an S-shaped calibration curve.
  • their flattening at the beginning and at the end falsifies the measurement result.
  • It is known to linearize the course of the calibration curve with the aid of amplifiers whose amplification factor changes as a function of the input voltage level.
  • each individual sensor type is assigned a specially adapted electronics unit.
  • the amplification factor in electronic units designed in this way is relatively strongly dependent on the level of the ambient temperature because of the necessary connection with non-linear resistors.
  • the sensor arrangement according to the invention with the characterizing features of the main claim has the advantage that the calibration curve is almost linear over the entire measuring range. There is therefore always a proportional relationship between the measuring signal and the immersion depth of the coil in the measuring tube. This is possible with the help of simple structural measures. Furthermore, even with a constant gain factor over the almost entire measuring range, i.e. A sufficiently precise proportional measuring voltage can be generated over the entire coil length.
  • FIG. 1 shows a circuit representation of the exemplary embodiment
  • FIG. 2 shows a section through a sensor arrangement in a simplified representation
  • FIG. 3 shows a non-linear calibration curve according to the prior art
  • FIG. 4 shows a modification of the exemplary embodiment according to FIG. 2.
  • an evaluation circuit is shown.
  • an alternator 10 has a measuring coil 11 with a high frequency quent alternating current feeds.
  • the measuring coil 11 is connected to the series resistor 13 to form a voltage divider 14.
  • a resistor 12 is connected in parallel with the measuring coil 11.
  • a diode 15 is connected in series with the series resistor 13.
  • a capacitor 16 is connected in parallel with the resistor 12.
  • a low-pass filter 19 consisting of a resistor 17 and a capacitor 18 is connected to the tap of the voltage divider 14 for smoothing the measured values.
  • a conventionally known amplifier circuit 20, which has two resistors 21, 22 and an operational amplifier 23, is connected in series with the low-pass filter 19.
  • FIG. 2 shows a sensor 26 which has a measuring tube 27 in which the measuring coil 11 wound on a core 28 in one layer can be moved.
  • the measuring coil 11 has regions 11a, 11b, 11c with different winding densities.
  • the core 28 is made of a non-electrically conductive material, e.g. Polyamide or PVC.
  • the measuring tube 27 is made of a highly conductive material.
  • the core 28 dips with the measuring coil 11 into the measuring tube 27, i.e. Core 28 and measuring tube 27 are moved relative to each other. Because of the eddy current effect, the AC resistance of the measuring coil 11 changes. Eddy currents are formed on the metallic inside of the measuring tube 27, which change the AC resistance of the measuring coil 11 and thus the applied voltage. This voltage, which is now different at the respective time, is rectified with the aid of the low-pass filter 19 and amplified with the amplifier circuit 20.
  • linearity errors are unavoidable in voltage dividers or bridge circuits in which the resistance value is changed only in part, in this case in the measuring coil 11.
  • These linearity errors can now be compensated for by a non-uniform winding of the measuring coil 11.
  • the windings are wound on the two outer regions 11a, 11c of the measuring coil 11 with different pitches compared to the central region 11b.
  • the windings on the two outer regions 11a, 11c of the measuring coil 11 should lie close to one another and continuously merge into a central region 11b with the same distance between the windings, ie the windings are no longer in contact with one another.
  • the end of the measuring coil 11, which first immerses in the measuring tube 27, has a shorter area 11c with a tight winding than the other end of the measuring coil 11.
  • This compression of the windings at the coil ends leads to an almost linear calibration curve 30 of the applied measuring voltage U via the immersion depth S of the measuring coil 11 into the measuring tube 27.
  • This different compression of the turns is necessary because the S-shaped calibration curve 30 has a different slope at the beginning and at the end of the immersion depth.
  • the linearity errors of the voltage divider or the bridge circuit can be compensated.
  • One explanation for this effect is an increase in the alternating magnetic field at the En to see that of the measuring coil 11, ie in the areas 11a and 11c, by a larger number of windings per coil length, and by the resulting higher number of damped turns.
  • the measuring coil on a hollow cylinder made of non-electrically conductive material, into which the metallic core is immersed. Eddy currents can form on its surface, as described above.
  • the sensor arrangement can also be operated using the inductive method.
  • the winding density is then to be matched to a calibration curve with a positive slope. The same conditions apply accordingly.

Abstract

A measurement coil (11) is connected to a voltage divider circuit (14) or bridge circuit. It is wound on to a core (28) and is moved relatively to a measurement tube (27). The measurement coil (11) has areas (11a, 11b, 11c) whose coil density differs in such a way that the voltage recorded at the output of the circuits has a linear characteristic curve corresponding to the movement of the measurement coil (11) relative to the measurement tube (27). It is possible to balance out the linearity errors in the voltage divider circuit (14) or bridge circuit, as well as the measurement errors in the measurement coil (11) due to the inhomogeneous magnetic field.

Description

SensoranordnungSensor arrangement
Stand der TechnikState of the art
Die Erfindung geht aus von einer Sensoranordnung nach der Gattung des Hauptanspruchs. Bei einer bekannten Anordnung besteht der Sensor aus einem Meßrohr sowie einer Spule, die einlagig und gleichmäßig auf einen Kern gewickelt ist und in eine Spannungsteiler- oder Brückenschaltung geschaltet ist. Dabei ergibt sich eine S-förmige Eichkurve. Deren Abflachungen am Anfang und am Ende verfälschen aber das Meßergebnis. Es ist bekannt, mit Hilfe von Verstärkern, deren Verstärkungsfaktor sich abhängig von der Eingangsspannungshöhe ändert, den Verlauf der Eichkurve zu linearisieren. Dies hat jedoch den Nachteil, daß jedem einzelnen Sensortyp eine speziell dafür angepaßte Elektronikeinheit zuzuordnen ist. Ferner ist der Verstärkungsfaktor bei so konzipierten Elektronikeinheiten wegen der dazu notwendigen Beschaltung mit nicht linearen Widerständen relativ stark von der Höhe der Umgebungstemperatur abhängig.The invention is based on a sensor arrangement according to the type of the main claim. In a known arrangement, the sensor consists of a measuring tube and a coil which is wound in one layer and uniformly on a core and is connected to a voltage divider or bridge circuit. This results in an S-shaped calibration curve. However, their flattening at the beginning and at the end falsifies the measurement result. It is known to linearize the course of the calibration curve with the aid of amplifiers whose amplification factor changes as a function of the input voltage level. However, this has the disadvantage that each individual sensor type is assigned a specially adapted electronics unit. Furthermore, the amplification factor in electronic units designed in this way is relatively strongly dependent on the level of the ambient temperature because of the necessary connection with non-linear resistors.
Ferner ist es bekannt, mit Hilfe unterschiedlicher Wicklungsdichte der Spule, d.h. geeigneter Zusatzwindungen, ein homogenes Magnetfeld zu erzeugen. Aber auch bei diesen Spu len ist keine lineare Eichkurve möglich, da die Meßwerte auch durch die Spannungsteiler- oder Brückenschaltung verfälscht werden.It is also known to generate a homogeneous magnetic field with the aid of different winding densities of the coil, ie suitable additional turns. But also with these Spu len, a linear calibration curve is not possible because the measured values are also falsified by the voltage divider or bridge circuit.
Vorteile der ErfindungAdvantages of the invention
Die erfindungsgemäße Sensoranordnung mit den kennzeichnenden Merkmalen des Hauptanspruchs hat demgegenüber den Vorteil, daß die Eichkurve über den gesamten Meßbereich nahezu linear verläuft. Es besteht somit stets ein proportionales Verhältnis zwischen Meßsignal und Eintauchtiefe der Spule in das Meßrohr. Dies ist mit Hilfe einfacher baulicher Maßnahmen möglich. Ferner kann auch bei einem konstanten Verstärkungsfaktor über den nahezu gesamten Meßbereich, d.h. über die gesamte Spulenlänge, eine hinreichend genaue proportionale Meßspannung erzeugt werden.The sensor arrangement according to the invention with the characterizing features of the main claim has the advantage that the calibration curve is almost linear over the entire measuring range. There is therefore always a proportional relationship between the measuring signal and the immersion depth of the coil in the measuring tube. This is possible with the help of simple structural measures. Furthermore, even with a constant gain factor over the almost entire measuring range, i.e. A sufficiently precise proportional measuring voltage can be generated over the entire coil length.
Durch die in den Unteransprüchen aufgeführten Maßnahmen sind vorteilhafte Weiterbildungen und Verbesserungen der im Hauptanspruch angegebenen Merkmale möglich.Advantageous further developments and improvements of the features specified in the main claim are possible through the measures listed in the subclaims.
Zeichnungdrawing
Ein Ausführungsbeispiel der Erfindung ist in der Zeichnung dargestellt und in der nachfolgenden Beschreibung näher erläutert. Es zeigen Figur 1 eine schaltungsgemäße Darstellung des Ausführungsbeispiels, Figur 2 einen Schnitt durch eine Sensoranordnung in vereinfachter Darstellung, Figur 3 eine nicht lineare Eichkurve nach dem Stand der Technik und Figur 4 eine Abwandlung des Ausführungsbeispiels nach Figur 2.An embodiment of the invention is shown in the drawing and explained in more detail in the following description. 1 shows a circuit representation of the exemplary embodiment, FIG. 2 shows a section through a sensor arrangement in a simplified representation, FIG. 3 shows a non-linear calibration curve according to the prior art, and FIG. 4 shows a modification of the exemplary embodiment according to FIG. 2.
Beschreibung des AusführungsbeispielsDescription of the embodiment
In Figur 1 ist eine Auswerteschaltung dargestellt, .in der ein Wechselstromgenerator 10 eine Meßspule 11 mit einem hochfre quenten Wechselstrom speist. Die Meßspule 11 ist mit dem Vorwiderstand 13 zu einem Spannungsteiler 14 verschaltet. Parallel zur Meßspule 11 ist ein Widerstand 12 geschaltet. In Reihe zum Vorwiderstand 13 liegt eine Diode 15. Ferner ist parallel zum Widerstand 12 ein Kondensator 16 geschaltet. Ein aus einem Widerstand 17 und einem Kondensator 18 bestehender Tiefpaß 19 ist zur Glättung der Meßwerte mit dem Abgriff des Spannungsteilers 14 verbunden. Ferner ist in Reihe zum Tiefpaß 19 eine herkömmlich bekannte Verstärkerschaltung 20 geschaltet, die zwei Widerstände 21, 22 und einen Operationsverstärker 23 aufweist.In Figure 1, an evaluation circuit is shown. In which an alternator 10 has a measuring coil 11 with a high frequency quent alternating current feeds. The measuring coil 11 is connected to the series resistor 13 to form a voltage divider 14. A resistor 12 is connected in parallel with the measuring coil 11. A diode 15 is connected in series with the series resistor 13. Furthermore, a capacitor 16 is connected in parallel with the resistor 12. A low-pass filter 19 consisting of a resistor 17 and a capacitor 18 is connected to the tap of the voltage divider 14 for smoothing the measured values. Furthermore, a conventionally known amplifier circuit 20, which has two resistors 21, 22 and an operational amplifier 23, is connected in series with the low-pass filter 19.
In Figur 2 ist ein Sensor 26 dargestellt, der ein Meßrohr 27 hat, in dem die auf einem Kern 28 einlagig aufgewickelte Meßspule 11 bewegbar ist. Die Meßspule 11 weist Bereiche 11a, 11b, 11c mit unterschiedlicher Wicklungsdichte auf. Der Kern 28 besteht aus einem nicht elektrisch leitfähigen Stoff, z.B. Polyamid oder PVC . Das Meßrohr 27 ist aus einem gut leitfähigen Stoff hergestellt.FIG. 2 shows a sensor 26 which has a measuring tube 27 in which the measuring coil 11 wound on a core 28 in one layer can be moved. The measuring coil 11 has regions 11a, 11b, 11c with different winding densities. The core 28 is made of a non-electrically conductive material, e.g. Polyamide or PVC. The measuring tube 27 is made of a highly conductive material.
Soll mit Hilfe des Sensors eine Position eingestellt oder eine Längenänderung bestimmt werden, so taucht der Kern 28 mit der Meßspule 11 in das Meßrohr 27 ein, d.h. Kern 28 und Meßrohr 27 werden relativ zueinander bewegt. Dabei verändert sich wegen des Wirbelstromeffektes der Wechselstromwiderstand der Meßspule 11. Auf der metallischen Innenseite des Meßrohrs 27 bilden sich Wirbelströme aus, die den Wechselstromwiderstand der Meßspule 11 und somit die anliegende Spannung verändern. Diese nun zum jeweiligen Zeitpunkt unterschiedliche, anliegende Spannung wird mit Hilfe des Tiefpasses 19 gleichgerichtet und mit der Verstärkerschaltung 20 verstärkt.If a position is to be set or a change in length is to be determined with the aid of the sensor, the core 28 dips with the measuring coil 11 into the measuring tube 27, i.e. Core 28 and measuring tube 27 are moved relative to each other. Because of the eddy current effect, the AC resistance of the measuring coil 11 changes. Eddy currents are formed on the metallic inside of the measuring tube 27, which change the AC resistance of the measuring coil 11 and thus the applied voltage. This voltage, which is now different at the respective time, is rectified with the aid of the low-pass filter 19 and amplified with the amplifier circuit 20.
Bei einer bisherigen, gleichförmig gewickelten Meßspule, d.h. einer Meßspule mit einheitlicher Steigung und gleichmäßiger Wicklungsdichte, sind die auf der Innenseite des Meßrohrs 27 durch sich ausbildende Wirbelströme verursachten Scheinwiderstandsänderungen in den Bereichen 11a, 11c an den Wicklungsenden geringer als in deren mittlerem Bereich 11b. Dies ist auf den, bezogen auf die gesamte Meßspulenlänge, nicht homogenen Verlauf des wirksamen magnetischen Wechselfeldes zurückzuführen. Im mittleren Bereich 11b der Meßspule wirken zur Erzeugung des magnetischen Wechselfeldes die Windungen der linken und der rechten Spulenhälfte zusammen, während hingegen am Ende der Meßspule entweder die links oder rechts davon liegenden Wicklungen fehlen. Ferner sind bei Spannungsteilern oder Brückenschaltungen, in denen nur in einem Teil, in diesem Fall in der Meßspule 11, der Widerstandswert verändert wird, Linearitätsfehler unvermeidbar. Diese Linearitätsfehler können nun durch eine uneinheitliche Wicklung der Meßspule 11 mit ausgeglichen werden. Dazu werden an den beiden äußeren Bereichen 11a, 11c der Meßspule 11 die Wicklungen mit unterschiedlicher Steigung gegenüber dem mittleren Bereich 11b gewickelt. Es sollen dabei die Wicklungen an den beiden äußeren Bereichen 11a, 11c der Meßspule 11 eng aneinanderliegen und kontinuierlich in einen mittleren Bereich 11b mit gleichem Abstand zwischen den Wicklungen übergehen, d.h. also die Wicklungen liegen nicht mehr aneinander an. Es ist ersichtlich, daß das Ende der Meßspule 11, das zuerst in das Meßrohr 27 eintaucht, einen kürzeren Bereich 11c mit dichter Wicklung aufweist, als das andere Ende der Meßspule 11. Durch diese Verdichtung der Windungen an den Spulenenden erreicht man eine nahezu lineare Eichkurve 30 der anliegenden Meßspannung U über die Eintauchtiefe S der Meßspule 11 in das Meßrohr 27. Diese unterschiedliche Verdichtung der Windungen ist notwendig, da die S-förmige Eichkurve 30 am Anfang und am Ende der Eintauchtiefe eine unterschiedliche Steigung aufweist. Ferner können dadurch die Linearitätsfehler des Spannungsteilers bzw. der Brückenschaltung ausgeglichen werden. Eine Erklärung für diesen Effekt ist in einer Verstärkung des magnetischen Wechselfeldes an den En den der Meßspule 11, d.h. in den Bereichen 11a und 11c, durch eine größere Anzahl von Wicklungen pro Spulenlänge zu sehen sowie an der dadurch bedingten höheren Anzahl von bedämpften Windungen.In a previous, uniformly wound measuring coil, ie a measuring coil with a uniform pitch and uniform winding density, these are on the inside of the measuring tube 27 Impedance changes in the regions 11a, 11c at the winding ends caused by eddy currents forming are less than in the central region 11b thereof. This is due to the non-homogeneous course of the effective alternating magnetic field, based on the entire length of the measuring coil. In the middle area 11b of the measuring coil, the windings of the left and right half of the coil interact to generate the alternating magnetic field, whereas, at the end of the measuring coil, either the windings lying to the left or right thereof are missing. Furthermore, linearity errors are unavoidable in voltage dividers or bridge circuits in which the resistance value is changed only in part, in this case in the measuring coil 11. These linearity errors can now be compensated for by a non-uniform winding of the measuring coil 11. For this purpose, the windings are wound on the two outer regions 11a, 11c of the measuring coil 11 with different pitches compared to the central region 11b. The windings on the two outer regions 11a, 11c of the measuring coil 11 should lie close to one another and continuously merge into a central region 11b with the same distance between the windings, ie the windings are no longer in contact with one another. It can be seen that the end of the measuring coil 11, which first immerses in the measuring tube 27, has a shorter area 11c with a tight winding than the other end of the measuring coil 11. This compression of the windings at the coil ends leads to an almost linear calibration curve 30 of the applied measuring voltage U via the immersion depth S of the measuring coil 11 into the measuring tube 27. This different compression of the turns is necessary because the S-shaped calibration curve 30 has a different slope at the beginning and at the end of the immersion depth. Furthermore, the linearity errors of the voltage divider or the bridge circuit can be compensated. One explanation for this effect is an increase in the alternating magnetic field at the En to see that of the measuring coil 11, ie in the areas 11a and 11c, by a larger number of windings per coil length, and by the resulting higher number of damped turns.
Selbstverständlich ist es auch denkbar, zusätzliche Spulenwindungen mit gleicher Feldrichtung an den beiden Enden der Meßspule 11 und somit mehrlagig anzuordnen. Ferner wären auch Zusatzspulen mit entgegengesetzter Feldrichtung in der Spulenmitte, d.h. im Bereich 11b, denkbar. Diese nun lineare Eichkurve kann mit Hilfe der Verstärkerschaltung 20 mit einem proportionalen Verstärkungsfaktor verstärkt werden.Of course, it is also conceivable to arrange additional coil turns with the same field direction at the two ends of the measuring coil 11 and thus in multiple layers. Furthermore, additional coils with opposite field direction would also be in the middle of the coil, i.e. in area 11b, conceivable. This now linear calibration curve can be amplified with the aid of the amplifier circuit 20 with a proportional amplification factor.
Wie in Figur 4 näher dargestellt, ist es auch möglich, die Wicklungen nicht nur am Anfang und am Ende der Meßspule 11 zu verdichten, sondern auch an jeder beliebigen Stelle der Meßspule. Durch diese Bereiche 33a, 33b mit enger bzw. weiter auseinander gezogenen Windungen der Meßspule 34 auf dem Kern 28 können Kennlinien erzeugt werden, de'ren Empfindlichkeiten abschnittsweise unterschiedlich groß sind. Dadurch kann die Empfindlichkeit der Meßspule 34 an bestimmte Erfordernisse, z.B. eine hohe Genauigkeit an wichtigen Meßpunkten, angepaßt werden.As shown in more detail in FIG. 4, it is also possible to compress the windings not only at the beginning and at the end of the measuring coil 11, but also at any point on the measuring coil. Characteristic curves can be generated by these areas 33a, 33b with closer or further apart windings of the measuring coil 34 on the core 28, the sensitivity of which varies in sections. This allows the sensitivity of the measuring coil 34 to certain requirements, e.g. high accuracy at important measuring points can be adjusted.
Ferner ist es auch möglich, die Meßspule auf einen aus nicht elektrisch leitenden Werkstoff hergestellten Hohlzylinder zu wickeln, in den der metallische Kern eintaucht. Auf dessen Oberfläche können sich, wie oben beschrieben, Wirbelströme ausbilden.Furthermore, it is also possible to wind the measuring coil on a hollow cylinder made of non-electrically conductive material, into which the metallic core is immersed. Eddy currents can form on its surface, as described above.
Die Sensoranordnung kann aber auch nach dem induktiven Verfahren betrieben werden. Die Wicklungsdichte ist dann auf eine Eichkurve mit positiver Steigung abzustimmen. Dabei gelten sinngemäß die gleichen Verhältnisse. However, the sensor arrangement can also be operated using the inductive method. The winding density is then to be matched to a calibration curve with a positive slope. The same conditions apply accordingly.

Claims

Ansprüche Expectations
1. Sensoranordnung mit einer Spule (11) und einem relativ zu dieser bewegten Kern (28), die von Wechselstrom durchflössen ist und in eine Spannungsteilerschaltung (14) oder in eine Brückenschaltung geschaltet ist, dadurch gekennzeichnet, daß die Spule (11) Bereiche (11a, 11b, 11c) mit unterschiedlicher Wicklungsanzahl derart aufweist, daß die am Ausgang der Schaltung abgegriffene Spannung eine lineare Kennlinie (30) bezogen auf die Relativbewegung der Spule (11) zum Kern (28) hat.1. A sensor arrangement with a coil (11) and a core (28) which is moved relative to the latter and through which alternating current flows and is connected to a voltage divider circuit (14) or to a bridge circuit, characterized in that the coil (11) has areas ( 11a, 11b, 11c) with different numbers of windings in such a way that the voltage tapped at the output of the circuit has a linear characteristic curve (30) related to the relative movement of the coil (11) to the core (28).
2. Sensoranordnung nach Anspruch 1, dadurch gekennzeich-net, daß die Spule (11) einlagig gewickelt ist.2. Sensor arrangement according to claim 1, characterized in that the coil (11) is wound in one layer.
3. Sensoranordnung nach Anspruch 1, dadurch gekennzeichnet, daß die Spule (11) mehrlagig gewickelt ist.3. Sensor arrangement according to claim 1, characterized in that the coil (11) is wound in several layers.
4. Sensoranordnung nach Anspruch 1, dadurch gekennzeichnet, daß die Spule (11) Bereiche (11a, 11b) mit zusätzlichen Spulen aufweist, die gleiche Feldrichtung wie die Spule (11) haben.4. Sensor arrangement according to claim 1, characterized in that the coil (11) regions (11a, 11b) with additional coils, have the same field direction as the coil (11).
5. Sensoranordnung nach Anspruch 1, dadurch gekennzeichnet, daß die Spule (11) Bereiche (11b) mit zusätzlichen Spulen aufweist, die entgegengesetzte Feldrichtung wie die Spule (11) haben. 5. Sensor arrangement according to claim 1, characterized in that the coil (11) has areas (11b) with additional coils which have opposite field direction as the coil (11).
6. Sensoranordnung nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß die Spule (11 ) am Anfang und am Ende Bereiche (11a, 11c) mit hoher Wicklungsdichte und einen mittleren Bereich mit geringer Wicklungsdichte aufweist.6. Sensor arrangement according to one of claims 1 to 5, characterized in that the coil (11) at the beginning and at the end regions (11a, 11c) with high winding density and a central region with low winding density.
7. Sensoranordnung nach Anspruch 6, dadurch gekennzeichnet, daß die Spule ( 11 ) am Anfang eine größere Wicklungsdichte aufweist als an ihrem Ende.7. Sensor arrangement according to claim 6, characterized in that the coil (11) has a greater winding density at the beginning than at its end.
8. Sensoranordnung nach einem der Ansprüche 1 bis 7, dadurch gekennzeichnet, daß sie zur Längenmessung dient. 8. Sensor arrangement according to one of claims 1 to 7, characterized in that it serves for length measurement.
PCT/DE1986/000182 1985-05-24 1986-05-02 Sensor arrangement WO1986007144A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DEP3518772.7 1985-05-24
DE19853518772 DE3518772A1 (en) 1985-05-24 1985-05-24 SENSOR ARRANGEMENT

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WO1986007144A1 true WO1986007144A1 (en) 1986-12-04

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EP (1) EP0221934A1 (en)
DE (1) DE3518772A1 (en)
ES (1) ES8707610A1 (en)
WO (1) WO1986007144A1 (en)

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EP0366227A2 (en) * 1988-10-27 1990-05-02 Macome Corporation A displacement measuring apparatus
WO1993004341A2 (en) * 1991-08-24 1993-03-04 Robert Bosch Gmbh Device for the non-contact measurement of the displacement or angle of rotation of a component
US5331277A (en) * 1992-08-07 1994-07-19 Eldec Corporation Inductive divider position sensor with fixed and variable impedance inductors
US5453685A (en) * 1993-07-30 1995-09-26 Philips Electronics North America Corporation Inductive position sensing device and apparatus with selectable winding configuration

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DE4301239A1 (en) * 1993-01-19 1994-07-21 Bosch Gmbh Robert Contactless position determination appts., e.g. for shock absorber
DE4331909A1 (en) * 1993-09-20 1995-03-23 Bosch Gmbh Robert Angle of rotation encoder
GB9607750D0 (en) * 1996-04-15 1996-06-19 Radiodetection Ltd Displacement sensors
DE19805120A1 (en) * 1998-02-09 1999-08-12 Asea Brown Boveri High voltage choke coil
JP2001272201A (en) * 2000-03-27 2001-10-05 Sony Precision Technology Inc Position detector
DE10120236C1 (en) * 2001-04-19 2003-01-30 Siemens Ag Electrical winding arrangement
DE10255710A1 (en) * 2002-11-29 2004-06-09 Hella Kg Hueck & Co. Inductive displacement sensor has electrical coil in detunable oscillating circuit, movable coil core in coil, coil body divided into at least two sections with different winding densities
DE10342473B4 (en) * 2003-09-15 2011-04-28 Sick Ag Magnetic displacement sensor
GB0707376D0 (en) * 2007-04-17 2007-05-23 Penny & Giles Controls Ltd Inductive sensors
DE102013200698A1 (en) * 2013-01-18 2014-07-24 Zf Friedrichshafen Ag Coil arrangement with two coils
DE102014201790A1 (en) 2013-02-01 2014-08-07 Continental Teves Ag & Co. Ohg Method of manufacturing a sensor
DE102013203586A1 (en) 2013-03-01 2014-09-04 Continental Teves Ag & Co. Ohg Sensor for detecting a position of a transmitter magnet

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GB1559091A (en) * 1976-11-24 1980-01-16 Marconi Co Ltd Position-voltage transducers
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DE3303994A1 (en) * 1982-02-17 1983-08-25 Deutsche Itt Industries Gmbh, 7800 Freiburg POSITION MEASURING DEVICE

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FR1144347A (en) * 1955-03-03 1957-10-11 Glanzstoff Ag Remote measurement indicator
DE1299432B (en) * 1967-12-30 1969-07-17 Maurer Ludwig Method and device for travel measurement in a piston-cylinder unit acted upon by a pressure medium
DE2314050A1 (en) * 1973-03-21 1974-10-03 Philips Patentverwaltung INDUCTIVE POSITION DETECTOR
GB1559091A (en) * 1976-11-24 1980-01-16 Marconi Co Ltd Position-voltage transducers
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Cited By (6)

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Publication number Priority date Publication date Assignee Title
EP0366227A2 (en) * 1988-10-27 1990-05-02 Macome Corporation A displacement measuring apparatus
EP0366227A3 (en) * 1988-10-27 1991-03-20 Macome Corporation A displacement measuring apparatus
WO1993004341A2 (en) * 1991-08-24 1993-03-04 Robert Bosch Gmbh Device for the non-contact measurement of the displacement or angle of rotation of a component
WO1993004341A3 (en) * 1991-08-24 1993-05-27 Bosch Gmbh Robert Device for the non-contact measurement of the displacement or angle of rotation of a component
US5331277A (en) * 1992-08-07 1994-07-19 Eldec Corporation Inductive divider position sensor with fixed and variable impedance inductors
US5453685A (en) * 1993-07-30 1995-09-26 Philips Electronics North America Corporation Inductive position sensing device and apparatus with selectable winding configuration

Also Published As

Publication number Publication date
DE3518772A1 (en) 1986-11-27
ES8707610A1 (en) 1987-08-01
ES555294A0 (en) 1987-08-01
EP0221934A1 (en) 1987-05-20

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