JP2587412B2 - Magnetic detector - Google Patents
Magnetic detectorInfo
- Publication number
- JP2587412B2 JP2587412B2 JP61212375A JP21237586A JP2587412B2 JP 2587412 B2 JP2587412 B2 JP 2587412B2 JP 61212375 A JP61212375 A JP 61212375A JP 21237586 A JP21237586 A JP 21237586A JP 2587412 B2 JP2587412 B2 JP 2587412B2
- Authority
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- Japan
- Prior art keywords
- detection
- coil
- magnetic
- magnetic field
- detection coil
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- Expired - Lifetime
Links
- 238000001514 detection method Methods 0.000 claims description 94
- 230000005284 excitation Effects 0.000 claims description 19
- 230000001360 synchronised effect Effects 0.000 claims description 15
- 239000004020 conductor Substances 0.000 claims description 9
- 230000006698 induction Effects 0.000 claims description 3
- 230000004907 flux Effects 0.000 description 12
- 238000013459 approach Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 7
- 230000007423 decrease Effects 0.000 description 5
- 239000000696 magnetic material Substances 0.000 description 5
- 239000000126 substance Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 230000000149 penetrating effect Effects 0.000 description 3
- 230000003321 amplification Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Landscapes
- Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)
- Measuring Magnetic Variables (AREA)
- Geophysics And Detection Of Objects (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、磁性体又は導電体を検知するための磁気検
知器に関し、特に、磁性体又は導電体をガイドレーンと
して走行する無人搬送車に使用されるカイドレーン用磁
気検知器に関するものである。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic detector for detecting a magnetic substance or a conductor, and more particularly, to an automatic guided vehicle traveling with a magnetic substance or a conductor as a guide lane. The present invention relates to a magnetic detector for use in a Kaidrain.
磁性体の存在を検知する磁気検知器の１つに、交流磁
場を発生する励起コイルとそれが作る磁場によって誘導
電圧を生ずる検知コイルから成る自己励磁型のものがあ
る。これは、構造が簡単で設計の自由度も大きいことか
ら、従来広く利用されており、効果をあげている。１つ
の利用分野として、この技術は種々の車両誘導システム
等に利用され役立っている。これらの誘導システムで
は、帯状の磁性体又は金属等の導電体をガイドレーンと
して誘導すべき道に設けて、誘導されるべきもの（車両
等）に取り付けられた検知器の信号からガイドレーンの
方向を知り、それに応じて操舵し、目的の場所に誘導す
るものである。One type of magnetic detector that detects the presence of a magnetic material is a self-excitation type including an excitation coil that generates an alternating magnetic field and a detection coil that generates an induced voltage by the magnetic field generated by the excitation coil. Since this is simple in structure and has a large degree of freedom in design, it has been widely used in the past and has been effective. As one application field, this technology is used and useful in various vehicle guidance systems and the like. In these guidance systems, a strip-shaped conductor such as a magnetic material or a metal is provided as a guide lane on a road to be guided, and the direction of the guide lane is determined based on a signal of a detector attached to a guided object (vehicle or the like). , And steer accordingly to guide the driver to a desired location.
従来の磁気検知器としては、第９図のコイル配置で第
10図の回路構成のものが知られている。この磁気検知器
の動作について説明する。まず、励起コイル２に発振器
１を接続して、交流電流を励起コイル２に流す。する
と、励起コイル２から励起磁界４が発生する。この励起
磁界４の一部が検知コイル3,3aを貫くことにより、検知
コイル3,3aに誘導電圧が生ずる。この誘導電圧は、第10
図の信号処理の回路に入力される。検知コイル3,3aの誘
導電圧はそれぞれ増幅回路5,5aを経て整流回路6,6aで整
流された後、差動回路７に入力され、検知コイル3,3aに
よる２つの信号の差が出力される。As a conventional magnetic detector, the coil arrangement shown in FIG.
The circuit configuration shown in FIG. 10 is known. The operation of this magnetic detector will be described. First, the oscillator 1 is connected to the excitation coil 2, and an alternating current flows through the excitation coil 2. Then, an excitation magnetic field 4 is generated from the excitation coil 2. When a part of the excitation magnetic field 4 passes through the detection coils 3, 3a, an induced voltage is generated in the detection coils 3, 3a. This induced voltage is
It is input to the signal processing circuit shown in the figure. After the induced voltages of the detection coils 3, 3a are rectified by the rectifier circuits 6, 6a via the amplifier circuits 5, 5a, respectively, they are input to the differential circuit 7, and the difference between the two signals by the detection coils 3, 3a is output. You.
このような構成・機能の磁気検知器において、検知コ
イル３に空気より大きな比透磁率をもつ磁性体が接近す
ると、磁界分布が変化し、検知コイルを貫く磁束も変化
する。また、導電体が接近すると、導電体に生ずる渦電
流により磁界が変化する。その結果、検知コイルに誘導
される電圧も変化することになる。磁性体又は導電体が
２つの検知コイルから対称な位置（第９図の中心軸Ｌ
上）にある場合は磁界分布は対称となり、２つの検知コ
イルの誘導電圧も等しいため、検知器出力も零となる。
しかし、磁性体又は導電体で作られたガイドレーンが片
側の検知コイルにより接近すると、左右の検知コイル電
圧が不平衡となり、差動回路７の出力電圧が不平衡の程
度に応じて正又は負となる。従って、この電圧を制御信
号として用いることにより、誘導されるべき物（車両
等）をガイドレーンに沿って走行させることができる。In a magnetic detector having such a configuration and function, when a magnetic body having a relative magnetic permeability higher than that of air approaches the detection coil 3, the magnetic field distribution changes, and the magnetic flux passing through the detection coil also changes. When the conductor approaches, the magnetic field changes due to eddy current generated in the conductor. As a result, the voltage induced in the detection coil also changes. The position where the magnetic material or the conductor is symmetrical from the two detection coils (the center axis L in FIG. 9).
In the case above, the magnetic field distribution is symmetric and the induced voltages of the two detection coils are equal, so that the detector output becomes zero.
However, when the guide lane made of a magnetic material or a conductor approaches the detection coil on one side, the left and right detection coil voltages become unbalanced, and the output voltage of the differential circuit 7 becomes positive or negative depending on the degree of unbalance. Becomes Therefore, by using this voltage as a control signal, an object to be guided (vehicle or the like) can travel along the guide lane.
次に、ガイドレーンである磁性体11に検知コイル３が
接近したときの磁界の変化について、より詳細に説明す
る。第３図は検知コイル３、ガイドレーンである磁性体
11およびその周辺の磁力線について示したものである。
実線９は磁性体11が両検知コイル３、3aの中央にある場
合の磁力線であり、破線10は磁性体11が両検知コイル
３、3aの中央の位置から検知コイル３に近接した場合の
磁力線である。第３図（ａ）に示すように、磁性体11が
検知コイル３に近接すると、磁力線は磁性体11に吸い込
まれるように実線９から破線10のように変化する。この
時、検知コイル３を垂直に貫く磁束の総和も、第３図
（ｂ）の実線矢印の大きさから破線矢印の大きさへと減
少し、誘導電圧は小さくなる。従って、第10図におい
て、磁性体11が近づいた側の整流回路６の出力は、もう
一方の整流回路6aの出力より小さくなり、差動回路７の
出力はそれに応じて正又は負となる。Next, the change of the magnetic field when the detection coil 3 approaches the magnetic body 11, which is a guide lane, will be described in more detail. FIG. 3 shows a detection coil 3 and a magnetic material serving as a guide lane.
11 shows the magnetic field lines 11 and its surroundings.
A solid line 9 is a line of magnetic force when the magnetic body 11 is located at the center between the two detection coils 3 and 3a. It is. As shown in FIG. 3 (a), when the magnetic body 11 approaches the detection coil 3, the line of magnetic force changes from the solid line 9 to the broken line 10 so as to be sucked into the magnetic body 11. At this time, the sum of the magnetic flux vertically penetrating the detection coil 3 also decreases from the size of the solid arrow in FIG. 3 (b) to the size of the dashed arrow, and the induced voltage decreases. Therefore, in FIG. 10, the output of the rectifier circuit 6 on the side closer to the magnetic body 11 becomes smaller than the output of the other rectifier circuit 6a, and the output of the differential circuit 7 becomes positive or negative accordingly.
〔発明が解決しようとする問題点〕 上述した従来の検知器では、走行車両を本来のガイド
レーンに戻す制御が可能である。しかし、走行車両が、
なんらかの原因で本来の走行路をさらに大きくはずれ、
ガドレーンである磁性体11が、検知コイル３の直下、さ
らにその外側にまで達するような場合、検知コイル３を
貫く磁束の総和は、しだいに減少してゆき、ある位置で
ゼロになる。その後、検知コイル３を貫く磁束の向きは
逆転し、磁束の総和は増加する傾向を示す。[Problems to be Solved by the Invention] With the above-described conventional detector, it is possible to control the traveling vehicle to return to the original guide lane. However, the traveling vehicle is
For some reason, it deviates much more from the original running path,
When the magnetic body 11 as a gadrain reaches immediately below and further outside the detection coil 3, the total amount of magnetic flux penetrating the detection coil 3 gradually decreases to zero at a certain position. Thereafter, the direction of the magnetic flux passing through the detection coil 3 is reversed, and the total of the magnetic flux tends to increase.
図４（ａ）、（ｂ）は、磁性体11が検知コイル３、3a
の中央に位置しているとき（実線９）と、磁性体11が検
知コイル３の近傍または検知コイル３を越える位置にあ
るとき（破線10）の、磁力線と検知コイル３を貫く磁束
の総和を示している。図４では、検知コイル３を貫く磁
束の向きは逆で、総和の絶対値は互いに等しい例を示し
ている。4 (a) and 4 (b) show that the magnetic body 11 has the detection coils 3 and 3a.
Of the magnetic field lines and the magnetic flux passing through the detection coil 3 when the magnetic body 11 is located near the detection coil 3 or beyond the detection coil 3 (dashed line 10). Is shown. FIG. 4 shows an example in which the directions of the magnetic flux passing through the detection coil 3 are opposite, and the absolute values of the sum are equal to each other.
しかし、検知コイル３を貫く磁束の総和がゼロからし
だいに増加とき、検知コイル３の出力電圧もゼロからし
だいに増加する。これは左右の検知コイル電圧の不均衡
が解消されるときの状況と同じである。従来の磁気検知
器は、このような状況下で、正常な制御が行われている
と判断し、結果的に誤った制御を行ってしまう。また仮
に検知コイル３、3aの出力が等しくなると、従来の磁気
検知器は、走行車両が正しい位置にあると判断してしま
う。However, when the sum of the magnetic flux passing through the detection coil 3 gradually increases from zero, the output voltage of the detection coil 3 also gradually increases from zero. This is the same situation as when the imbalance between the left and right detection coil voltages is resolved. Under such circumstances, the conventional magnetic detector determines that normal control is being performed, and consequently performs erroneous control. Further, if the outputs of the detection coils 3 and 3a become equal, the conventional magnetic detector determines that the traveling vehicle is at the correct position.
このような欠点を除去するために本発明は、両端から
交流磁界を発生する励起コイルと、この励起コイルの両
側に設けられ、励起コイルの作る磁界によって誘導電圧
を生ずる第１、第２の検知コイルと、励起コイルからの
磁界が常に同一の向きとなる位置に設けられ、この磁界
によって誘導電圧を生ずる位相検知コイルと、第１の検
知コイルの誘導電圧による検知信号を位相検知コイルの
誘導電圧による同期信号により同期検波する第１の同期
検波回路と、第２の検知コイルの誘導電圧による検知信
号を位相検知コイルの誘導電圧による同期信号により同
期検波する第２の同期検波回路と、第１、第２の同期検
波回路からの出力の差をとる差動回路とを検知器に設け
るようにしたものである。In order to eliminate such a drawback, the present invention provides an excitation coil for generating an alternating magnetic field from both ends, and first and second detection coils provided on both sides of the excitation coil and generating an induced voltage by a magnetic field generated by the excitation coil. A phase detection coil that generates an induced voltage by the magnetic field from the coil and the excitation coil, and a detection signal based on the induced voltage of the first detection coil. A first synchronous detection circuit for synchronously detecting the synchronous signal based on the synchronous signal of the first and second detection coils, a second synchronous detection circuit for synchronously detecting the detection signal based on the induced voltage of the second detection coil by the synchronous signal based on the induced voltage of the phase detection coil, and a first synchronous detection circuit. And a differential circuit for obtaining a difference between outputs from the second synchronous detection circuit are provided in the detector.
本発明においては、検知コイルを貫く磁束の向きが反
転した時には負電圧が出力される。In the present invention, a negative voltage is output when the direction of the magnetic flux passing through the detection coil is reversed.
本発明に係わる磁気検知器の一実施例を第１図および
第２図に示す。第１図は本検知器の各構成の配置を示す
配置図、第２図は本検知器の回路を示す回路図である。
第１図および第２図において第９図および第10図と同一
部分又は相当部分には同一符号が付してある。One embodiment of a magnetic detector according to the present invention is shown in FIGS. FIG. 1 is a layout diagram showing an arrangement of each component of the present detector, and FIG. 2 is a circuit diagram showing a circuit of the present detector.
1 and 2, the same or corresponding parts as those in FIGS. 9 and 10 are denoted by the same reference numerals.
第１図において、励起コイル２は発振器１からの交流
電流により磁界を発生する。この磁界の一部が第１、第
２の検知コイル3,3aを貫くことにより検知コイル3,3aに
は誘導電圧が生ずる。位相検知コイル８は、励起コイル
２から発生する磁界を常に同一位相で貫く位置に設置さ
れる。第２図において、検知コイル3,3aの誘導電圧は、
増幅回路12,12aで増幅されて検知信号a1,a2となる。こ
の検知信号a1,a2は、第１、第２の同期検波回路13,13a
で、位相検知コイル８で生じた誘導電圧を増幅した信号
である同期信号ｂにより同期検波される。In FIG. 1, an excitation coil 2 generates a magnetic field by an alternating current from an oscillator 1. When a part of this magnetic field passes through the first and second detection coils 3, 3a, an induced voltage is generated in the detection coils 3, 3a. The phase detection coil 8 is installed at a position where the magnetic field generated from the excitation coil 2 always passes through the same phase. In FIG. 2, the induced voltage of the detection coils 3, 3a is
The signals are amplified by the amplifier circuits 12 and 12a and become detection signals a1 and a2. The detection signals a1, a2 are supplied to first and second synchronous detection circuits 13, 13a.
Then, synchronous detection is performed by the synchronous signal b, which is a signal obtained by amplifying the induced voltage generated in the phase detecting coil 8.
このような構成・機能の本検知器に磁性体が接近して
磁力線分布が第３図（ａ）のように変化した場合の第２
図の回路の各部波形を第５図に示し、第４図（ａ）のよ
うに変化した場合の各部波形を第６図に示す。第５図
（ａ）および第６図（ａ）は検知コイル3,3aの誘導電圧
を増幅回路12,12aで増幅した信号である検知信号a1（破
線）,a2（実線）を示し、第５図（ｂ）および第６図
（ｂ）は位相検知コイル８の誘導電圧を増幅回路12bで
増幅した信号である同期信号ｂを示し、第５図（ｃ）お
よび第６図（ｃ）は同期検波回路13,13aの出力である検
波信号c1（破線）,c2（実線）を示す。In the case where the magnetic body approaches the present detector having such a configuration and function, and the magnetic field line distribution changes as shown in FIG.
FIG. 5 shows the waveform of each part of the circuit shown in FIG. 5, and FIG. 6 shows the waveform of each part when it changes as shown in FIG. 4 (a). 5 (a) and 6 (a) show detection signals a1 (broken line) and a2 (solid line), which are signals obtained by amplifying the induced voltages of the detection coils 3, 3a by the amplifier circuits 12, 12a. 6 (b) and 6 (b) show a synchronization signal b which is a signal obtained by amplifying the induced voltage of the phase detection coil 8 by the amplifier circuit 12b, and FIGS. 5 (c) and 6 (c) show the synchronization signal b. The detection signals c1 (broken line) and c2 (solid line) output from the detection circuits 13 and 13a are shown.
第５図（ａ）に示す破線の検知信号a1,第５図（ｃ）
に示す破線の検波信号c1は、第３図（ａ）の磁性体11に
よる信号である。検波信号c2は磁性体11の影響のない検
知コイル3aの誘導電圧によるものである。検波信号c1の
レベルは、第３図（ｂ）に示すような検知コイル３を貫
く磁束量の減少によりV1となり、磁性体11の影響のない
検波信号c2のレベルV2より小さな値となっている。FIG. 5 (a) shows a detection signal a1 indicated by a broken line in FIG. 5 (a).
A detection signal c1 indicated by a broken line shown in FIG. 3 is a signal generated by the magnetic body 11 shown in FIG. The detection signal c2 is based on the induced voltage of the detection coil 3a which is not affected by the magnetic body 11. The level of the detection signal c1 becomes V1 due to the decrease in the amount of magnetic flux penetrating through the detection coil 3 as shown in FIG. 3 (b), and is smaller than the level V2 of the detection signal c2 which is not affected by the magnetic body 11. .
また、第６図（ａ）に示す破線の検知信号a1,第６図
（ｃ）に示す破線の検波信号c1は、第４図の磁性体11に
よる信号である。第５図の場合と同様に、検波信号c2は
磁性体11の影響のない検知コイル3aの誘導電圧によるも
のである。検波信号c1のレベルは、第６図（ａ）に示す
ように検知信号a1の位相が反転しているため、正から負
へ極性が反転している。The detection signal a1 indicated by a broken line in FIG. 6 (a) and the detection signal c1 indicated by a broken line in FIG. 6 (c) are signals from the magnetic body 11 in FIG. As in the case of FIG. 5, the detection signal c2 is based on the induced voltage of the detection coil 3a which is not affected by the magnetic substance 11. As shown in FIG. 6A, the level of the detection signal c1 is inverted from positive to negative because the phase of the detection signal a1 is inverted.
位相検知コイル８は、磁性体11による磁界の乱れによ
っても一定の位相（向き）に磁力線が貫く位置に設置さ
れているため、検知コイル3,3aを貫く磁力線の位相（向
き）の基準となり得る。従って、位相検知コイル８の誘
導電圧による同期信号を用い同期検波された検波信号
は、磁性体11との距離が小さくなるに従い、正から負へ
と変化する。Since the phase detection coil 8 is provided at a position where the magnetic field lines penetrate in a constant phase (direction) even by the disturbance of the magnetic field due to the magnetic body 11, it can be a reference for the phase (direction) of the magnetic field lines passing through the detection coils 3, 3a. . Therefore, the detection signal synchronously detected using the synchronization signal based on the induced voltage of the phase detection coil 8 changes from positive to negative as the distance from the magnetic body 11 decreases.
本実施例においては、位相検知コイル８は、磁性体又
は導電体の接近時にも磁界の乱れにより位相が反転しな
い位置にあれば十分であり、第７図に示すように励起コ
イル２に巻回するものであっても良い。また、検知コイ
ル3,3aは、第８図に示すように、コイルの軸が紙面に垂
直方向に設置されたものであっても同様の効果を奏す
る。In this embodiment, it is sufficient that the phase detection coil 8 is located at a position where the phase is not inverted due to the disturbance of the magnetic field even when the magnetic substance or the conductor approaches, and the phase detection coil 8 is wound around the excitation coil 2 as shown in FIG. You may do. Further, as shown in FIG. 8, the same effect can be obtained with the detection coils 3, 3a even if the coil axis is set in a direction perpendicular to the plane of the drawing.
以上説明したように本発明は、位相の基準となる位相
検知コイルを設け、この位相検知コイルの誘導電圧によ
る同期信号を用いて検知コイルの誘導電圧による検知信
号を同期検波することにより、検知コイルを貫く磁束の
向きが反転した時に負電圧を出力することができ、磁性
体が接近するに従い、検波信号を単調に減少させること
ができるので、磁性体の有無を明確に区別できる効果が
ある。As described above, the present invention provides a phase detection coil serving as a phase reference, and synchronously detects the detection signal based on the induction voltage of the detection coil using the synchronization signal based on the induction voltage of the phase detection coil, thereby detecting the detection coil. A negative voltage can be output when the direction of the magnetic flux passing through is reversed, and the detection signal can be monotonously reduced as the magnetic body approaches, so that there is an effect that the presence or absence of the magnetic body can be clearly distinguished.
第１図は本発明に係わる磁気検知器の一実施例を示す配
置図、第２図はその回路を示す回路図、第３図および第
４図は磁性体の接近による磁束分布の変化を示す説明
図、第５図および第６図は第３図および第４図に対応し
て第２図の回路の各部波形を示す波形図、第７図は本発
明の第２の実施例を示す配置図、第８図は本発明の第３
の実施例を示す配置図、第９図は従来の磁気検知器の構
成を示す配置図、第10図はその回路を示す回路図であ
る。 １……発振器、２……励起コイル、3,3a……検知コイ
ル、４……磁力線、７……差動回路、８……位相検知コ
イル、12,12a,12b……増幅回路、13,13a……同期検波回
路。FIG. 1 is a layout diagram showing one embodiment of a magnetic detector according to the present invention, FIG. 2 is a circuit diagram showing its circuit, and FIGS. 3 and 4 show changes in magnetic flux distribution due to approach of a magnetic body. 5 and 6 are waveform diagrams showing waveforms of respective parts of the circuit of FIG. 2 corresponding to FIGS. 3 and 4, and FIG. 7 is an arrangement showing a second embodiment of the present invention. FIG. 8 shows the third embodiment of the present invention.
FIG. 9 is a layout diagram showing a configuration of a conventional magnetic detector, and FIG. 10 is a circuit diagram showing a circuit thereof. DESCRIPTION OF SYMBOLS 1 ... Oscillator, 2 ... Excitation coil, 3,3a ... Detection coil, 4 ... Line of magnetic force, 7 ... Differential circuit, 8 ... Phase detection coil, 12,12a, 12b ... Amplification circuit, 13, 13a: Synchronous detection circuit.
フロントページの続き (56)参考文献 特開 昭58−58488（ＪＰ，Ａ) 特開 昭59−60275（ＪＰ，Ａ) 特開 昭60−118912（ＪＰ，Ａ) 特開 昭53−114497（ＪＰ，Ａ) 実開 昭61−84887（ＪＰ，Ｕ) 実開 昭61−46463（ＪＰ，Ｕ) 特公 昭57−15703（ＪＰ，Ｂ２)Continuation of the front page (56) References JP-A-58-58488 (JP, A) JP-A-59-60275 (JP, A) JP-A-60-118912 (JP, A) JP-A-53-114497 (JP) , A) Japanese Utility Model Showa 61-84887 (JP, U) Japanese Utility Model Showa 61-46463 (JP, U) Japanese Patent Publication No. 57-15703 (JP, B2)
Claims (1)
する無人搬送車に用いられる磁気検知器において、 両端から交流磁界を発生する励起コイルと、 この励起コイルの両側に設けられ、励起コイルの作る磁
界によって誘導電圧を生ずる第１、第２の検知コイル
と、 励起コイルからの磁界が常に同一の向きとなる位置に設
けられ、この磁界によって誘導電圧を生ずる位相検知コ
イルと、 第１の検知コイルの誘導電圧による検知信号を位相検知
コイルの誘導電圧による同期信号により同期検波する第
１の同期検波回路と、 第２の検知コイルの誘導電圧による検知信号を位相検知
コイルの誘導電圧による同期信号により同期検波する第
２の同期検波回路と、 第１、第２の同期検波回路からの出力の差をとる差動回
路とを備えたことを特徴とする磁気検知器。1. A magnetic detector used in an automatic guided vehicle that travels using a magnet or a conductor as a guide lane, comprising: an excitation coil for generating an AC magnetic field from both ends; and an excitation coil provided on both sides of the excitation coil. A first and a second detection coil for generating an induced voltage by a magnetic field; a phase detection coil for providing an induced voltage by the magnetic field, the phase detection coil being provided at a position where the magnetic field from the excitation coil always has the same direction; A first synchronous detection circuit for synchronously detecting a detection signal based on the induced voltage of the phase detection coil by a synchronization signal based on the induction voltage of the phase detection coil; A second synchronous detection circuit for performing synchronous detection, and a differential circuit for obtaining a difference between outputs from the first and second synchronous detection circuits. Magnetic detectors.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61212375A JP2587412B2 (en) | 1986-09-09 | 1986-09-09 | Magnetic detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61212375A JP2587412B2 (en) | 1986-09-09 | 1986-09-09 | Magnetic detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6367583A JPS6367583A (en) | 1988-03-26 |
| JP2587412B2 true JP2587412B2 (en) | 1997-03-05 |
Family
ID=16621523
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61212375A Expired - Lifetime JP2587412B2 (en) | 1986-09-09 | 1986-09-09 | Magnetic detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2587412B2 (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59215497A (en) * | 1983-05-19 | 1984-12-05 | Hitachi Cable Ltd | Plating method of fiber bundle |
| JP2652196B2 (en) * | 1988-05-24 | 1997-09-10 | 日本車輌製造株式会社 | Guidance detection device and guidance control method for automatic guided vehicle |
| US9817078B2 (en) | 2012-05-10 | 2017-11-14 | Allegro Microsystems Llc | Methods and apparatus for magnetic sensor having integrated coil |
| US10145908B2 (en) | 2013-07-19 | 2018-12-04 | Allegro Microsystems, Llc | Method and apparatus for magnetic sensor producing a changing magnetic field |
| US10495699B2 (en) | 2013-07-19 | 2019-12-03 | Allegro Microsystems, Llc | Methods and apparatus for magnetic sensor having an integrated coil or magnet to detect a non-ferromagnetic target |
| US9823092B2 (en) | 2014-10-31 | 2017-11-21 | Allegro Microsystems, Llc | Magnetic field sensor providing a movement detector |
| US10012518B2 (en) | 2016-06-08 | 2018-07-03 | Allegro Microsystems, Llc | Magnetic field sensor for sensing a proximity of an object |
| US10837943B2 (en) | 2017-05-26 | 2020-11-17 | Allegro Microsystems, Llc | Magnetic field sensor with error calculation |
| US10996289B2 (en) | 2017-05-26 | 2021-05-04 | Allegro Microsystems, Llc | Coil actuated position sensor with reflected magnetic field |
| US11428755B2 (en) | 2017-05-26 | 2022-08-30 | Allegro Microsystems, Llc | Coil actuated sensor with sensitivity detection |
| US10823586B2 (en) | 2018-12-26 | 2020-11-03 | Allegro Microsystems, Llc | Magnetic field sensor having unequally spaced magnetic field sensing elements |
| US11237020B2 (en) | 2019-11-14 | 2022-02-01 | Allegro Microsystems, Llc | Magnetic field sensor having two rows of magnetic field sensing elements for measuring an angle of rotation of a magnet |
| US11280637B2 (en) | 2019-11-14 | 2022-03-22 | Allegro Microsystems, Llc | High performance magnetic angle sensor |
| US11262422B2 (en) | 2020-05-08 | 2022-03-01 | Allegro Microsystems, Llc | Stray-field-immune coil-activated position sensor |
| US11493361B2 (en) | 2021-02-26 | 2022-11-08 | Allegro Microsystems, Llc | Stray field immune coil-activated sensor |
| US11578997B1 (en) | 2021-08-24 | 2023-02-14 | Allegro Microsystems, Llc | Angle sensor using eddy currents |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5715703A (en) * | 1980-06-30 | 1982-01-27 | Hasegawa Taiiku Shisetsu Kk | Playground |
| JPS5858488A (en) * | 1981-10-02 | 1983-04-07 | Nippon Telegr & Teleph Corp <Ntt> | Detector for object buried in ground |
| JPS5960275A (en) * | 1982-09-30 | 1984-04-06 | Anritsu Corp | Metal detector |
| JPS6146463U (en) * | 1984-08-30 | 1986-03-28 | ティーディーケイ株式会社 | magnetic sensing device |
| JPS6184887U (en) * | 1984-11-09 | 1986-06-04 |
-
1986
- 1986-09-09 JP JP61212375A patent/JP2587412B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6367583A (en) | 1988-03-26 |
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