JPS6046124A - Proximity switch - Google Patents

Proximity switch

Info

Publication number
JPS6046124A
JPS6046124A JP15371983A JP15371983A JPS6046124A JP S6046124 A JPS6046124 A JP S6046124A JP 15371983 A JP15371983 A JP 15371983A JP 15371983 A JP15371983 A JP 15371983A JP S6046124 A JPS6046124 A JP S6046124A
Authority
JP
Japan
Prior art keywords
circuit
current
proximity switch
feedback
switch
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP15371983A
Other languages
Japanese (ja)
Other versions
JPH039650B2 (en
Inventor
Shigeru Aoshima
滋 青島
Shinichi Kuno
久野 真一
Ikuo Nishimoto
育夫 西本
Giichi Kawashima
川島 義一
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Azbil Corp
Original Assignee
Azbil Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Azbil Corp filed Critical Azbil Corp
Priority to JP15371983A priority Critical patent/JPS6046124A/en
Publication of JPS6046124A publication Critical patent/JPS6046124A/en
Publication of JPH039650B2 publication Critical patent/JPH039650B2/ja
Granted legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03KPULSE TECHNIQUE
    • H03K17/00Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/94Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
    • H03K17/945Proximity switches

Landscapes

  • Electronic Switches (AREA)
  • Switches That Are Operated By Magnetic Or Electric Fields (AREA)

Abstract

PURPOSE:To make a proximity switch make stable operation with respect to the sensitive distance of the switch, by making the current capacity of two transistors of a current mirror circuit which supplies a feedback current to the resonance circuit of the proximity switch different from each other. CONSTITUTION:A feedback circuit which supplies a feedback current from the oscillating circuit 12 of a proximity switch to a resonance circuit 21 which detects the approach of metals, etc., is constituted with a current mirror circuit composed of transistors (TR) 35 and 36. (n) pieces of TRs 36 are connected in parallel with each other so that the current capacity of the mirroring side TR36 of this circuit can be enlarged to (n) times of the current capacity of the mirrored side TR35. When an AC voltage appearing at the upper end of the resonance circuit 21 is represented as V1C and the value of the operating distance adjusting resistance 22 of the switch is represented as R22, the AC component iC of the collector current of a TR33 becomes iC=V1C/nR22. Therefore, the resistance value for obtaining the feedback current can be reduced to 1/n and approach detection stably operates even when the resistance value fluctuates.

Description

【発明の詳細な説明】 この発明は高周波発振形の近接スイッチの改良に関する
ものである。
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a high frequency oscillation type proximity switch.

一般にこの種の近接スイッチは第1図に示すように構成
されている。この図において近接スイッチ10は近接セ
ンサ回路をなす10回路1と、このIO回路のみでは出
力電流容量が不足するので追加されたトランジスタ16
とにより構成されている。このIO回路は内部に発振回
路2、コンパレータ3、積分回路4%コンパレータ5、
出力回路6、定電圧回路7および電源リセット回路8を
有しており、検出コイル11.共振コイル16、感度調
整用可変抵抗12、側路コンデンブ14、電源リセット
用コンデンサ15などが外付けされる。
Generally, this type of proximity switch is constructed as shown in FIG. In this figure, the proximity switch 10 includes a 10 circuit 1 forming a proximity sensor circuit, and a transistor 16 which is added because the output current capacity is insufficient with only this IO circuit.
It is composed of. This IO circuit has an oscillation circuit 2, a comparator 3, an integration circuit 4% comparator 5,
It has an output circuit 6, a constant voltage circuit 7, and a power supply reset circuit 8, and a detection coil 11. A resonance coil 16, a sensitivity adjustment variable resistor 12, a bypass condenser 14, a power supply reset capacitor 15, and the like are externally attached.

発振回路2は検出コイル11を含んで形成されて発振し
ており、物体がこの検出コイル11に近づくと発振振幅
が減衰し、オたは発振を停!トする。そしてこの発fM
振幅の変化はコンパレータ3により電圧比較され、さら
にこの検波出力は積分回路4により積分されて、この積
分出力はコンパレータ5に設けたレベル比較電圧と比較
され、そのコンパレータの出力により出力回路6の出力
状態を制御する。
The oscillation circuit 2 includes a detection coil 11 and oscillates. When an object approaches this detection coil 11, the oscillation amplitude is attenuated and the oscillation stops! to And this fM
The change in amplitude is compared with voltage by comparator 3, this detection output is further integrated by integration circuit 4, this integrated output is compared with a level comparison voltage provided in comparator 5, and the output of output circuit 6 is determined by the output of the comparator. Control the state.

そして従来の発振回路2は第2図に示すように構成され
ていた。この図において21はLO共振回路、22は外
付けの可変抵抗、31は足電流源、 32 t、tレベ
ルシフト回路%33〜35H)ランジスタである。
The conventional oscillation circuit 2 was constructed as shown in FIG. In this figure, 21 is an LO resonance circuit, 22 is an external variable resistor, 31 is a foot current source, and 32 is a transistor (t, t level shift circuit).

そ1.て1・C共振回路21のト端にあられれた電FF
klニレベルシフト回路32によってトランジスタ33
の能動領域である動作点にシフトされ、トランジスタ3
:H,l:抵抗22をエミッタ抵抗とするエミッタフォ
ロワー回路に構成されている。またL(]共411φ回
路21の1を端にあられれる交流電圧なV1cトスるど
トランジスタ33のコレクタ電流の交流、成分icは ic= Vlc / a 22 ・・・ 1】)となる
。この電流をトランジスタ34と35からなるカレント
ミラー回路によってLOC共振回路21帰還させて発振
させている。言うまでもなく近接スイッチは被検出体が
L C共振回路21のコイルに接近1−タ、ときにコイ
ルの損失が増加して発振振幅が小さくなったこと、ある
いは発振が停止1−7たことを検知してスイッチング動
作を行っている。しかも近接スイッチの機能と1−て被
検出体がコイルV(列しである一定の距離に接近したと
きにスイッチをオン、オフ動作させる必要がある。とこ
ろがT、C共振回路に用いられるコイルはばらつきが大
きいので、動作距離を調整するために回路側のゲインを
調整する方法が一般に用いられる。
Part 1. The electric FF placed at the top end of the 1-C resonant circuit 21
transistor 33 by kl two-level shift circuit 32
is shifted to the operating point which is the active region of transistor 3.
:H, l: Constructed as an emitter follower circuit using the resistor 22 as an emitter resistor. In addition, when L() is an AC voltage V1c which is applied to the terminal 1 of the 411φ circuit 21, the AC component ic of the collector current of the transistor 33 becomes ic=Vlc/a 22 . . . 1]). This current is fed back to the LOC resonance circuit 21 by a current mirror circuit made up of transistors 34 and 35 to cause oscillation. Needless to say, the proximity switch detects when the object to be detected approaches the coil of the LC resonance circuit 21, the oscillation amplitude becomes smaller due to increased coil loss, or the oscillation stops. switching operation. Moreover, the function of the proximity switch is that it is necessary to turn on and off the switch when the detected object approaches the coil V (lined up at a certain distance). However, the coils used in the T and C resonance circuits Since the variation is large, a method of adjusting the gain on the circuit side is generally used to adjust the operating distance.

そのために抵抗、R22はToの内l1l(には設けら
れず外付は部品とし、LOC共振回路■cとを接続した
後、被検出体を所定の距離に近づけてスイッチ動作をす
るように抵抗R22をトリミングしている。その後組付
けのためにボッチjりおよび充填剤で充填をするが、抵
抗1’t22の両端にはLOC共振回路発振した高周波
の電圧があられれているために、ボッティングあるいは
充電による浮遊容量によるインピーダンスが抵抗R22
に比して無視できないものとなり、スイッチの動作距離
が所定の距離からずれる欠点があった。またこの浮遊容
量はボッティングあるいは充填の材料およびその方法に
よって予測で舞るものではなく、また温度による共振コ
ンデンサの容量の挙動も不安定 1であり、近接スイッ
チの動作を不安定なものにしていた。
For this reason, the resistor R22 is not provided in l1l (of To) and is an external component, and after connecting the LOC resonant circuit ■c, the resistor is connected to the object to be detected at a predetermined distance to operate the switch. R22 is trimmed.After that, it is filled with filler for assembly, but since the high frequency voltage generated by the LOC resonant circuit is applied to both ends of the resistor 1't22, The impedance due to stray capacitance due to charging or charging is the resistance R22.
This is not negligible compared to the above, and there is a drawback that the operating distance of the switch deviates from a predetermined distance. Furthermore, this stray capacitance does not vary predictably depending on the botting or filling material and method, and the behavior of the capacitance of the resonant capacitor due to temperature is also unstable1, making the operation of the proximity switch unstable. Ta.

この発明はこのような従来の欠点を解消しようとするも
ので、以下図面を参照してこの発明の一実fifii例
について説明する。
The present invention aims to eliminate such conventional drawbacks, and one practical example of the present invention will be described below with reference to the drawings.

−J” 3わら第3図はカレントミラーを構成するトラ
ンジスタ35.36の中、ダイオード接続されるトラン
ジスタ36をトランジスタ35に比してn個並列に接続
したトランジス5群あるいは0倍の面積11;を看゛す
るトランジスタで構成したものでその他の構IJv、に
ついては第2図に示すものと同様であるのでその説明を
省略する。
-J" 3 Figure 3 shows a group of 5 transistors in which n diode-connected transistors 36 are connected in parallel compared to the transistor 35 among the transistors 35 and 36 constituting the current mirror, or an area 11 that is 0 times larger than the transistor 35; The other structure, IJv, is the same as that shown in FIG. 2, so a description thereof will be omitted.

したがって第3図における帰還電流irは1r=−Vl
c / n 1(22−121とkす、11)式と同じ
帰還電流を得るため、すなわ/ ち同じゲインを得るためにけR22= R22/ nと
なり、このため外付は抵抗11.22の値は小さくて済
む。
Therefore, the feedback current ir in FIG. 3 is 1r=-Vl
c/n 1 (22-121 and k, 11) In order to obtain the same feedback current as in equation 11, that is, to obtain the same gain, R22 = R22/n, and therefore the external resistor 11.22 The value of can be small.

第4図はP N l) )ランジスタの電流増幅率βが
(1t:い/Cめに、温厖によるβの変化の影蕾が大き
くあられれることを1(メ1ぐためにトランジスタ37
を付方1117、ウィルソン型のカレントミラーを採用
した回路である、 この発明はト述のようにカレントミラー回路のミラーす
る方のトランジスタの電流@量をミラーされる方のトラ
ンジスタの電流容量に比し大にしたので、感度調整用の
抵抗R22の値を小さくすることがで叛るのでその両端
に付随する浮遊容量がもつインピーダンスの!5響を相
対的に小さくすることができ、したがってスイッチ感応
距離を調整した後ポツティングおよび充填を行っても感
応距離が変化せず、しか亀温度変化による浮遊容置変化
の影着が大きく減少し、温度に対して安定なスイッチン
グ動作をする利点がある。
Figure 4 shows that the current amplification factor β of the transistor (P N l)) is (1t:I/C), so the effect of the change in β due to temperature is large.
Attachment 1117 is a circuit that employs a Wilson type current mirror.As mentioned above, this invention compares the amount of current of the mirrored transistor of the current mirror circuit to the current capacity of the mirrored transistor. Since the value of the sensitivity adjustment resistor R22 is set to a large value, the impedance of the stray capacitance attached to both ends of the resistor R22 is reduced. 5 effects can be made relatively small, so even if potting and filling are performed after adjusting the switch sensitive distance, the sensitive distance does not change, and the influence of floating volume changes due to temperature changes is greatly reduced. It has the advantage of stable switching operation over temperature.

【図面の簡単な説明】 第1図は一般の近接スイッチのブロック回路図、第2図
は従来の発振回路の回路図、第3図はこの発明における
近接スイッチの発振回路の回路図、第4図はこの発明の
他の実施例を示す回路図である。 2・・・発振回路、21・・・LOC共振回路22・・
・感度調整用抵抗、31.33.34.35・・・トラ
ンジスタ。 特許出願人 山武ハネウェル株式会社 「0(■
[Brief Description of the Drawings] Fig. 1 is a block circuit diagram of a general proximity switch, Fig. 2 is a circuit diagram of a conventional oscillation circuit, Fig. 3 is a circuit diagram of an oscillation circuit of a proximity switch according to the present invention, and Fig. 4 is a circuit diagram of a conventional oscillation circuit. The figure is a circuit diagram showing another embodiment of the invention. 2...Oscillation circuit, 21...LOC resonance circuit 22...
- Sensitivity adjustment resistor, 31.33.34.35...transistor. Patent applicant Yamatake Honeywell Co., Ltd. “0 (■

Claims (1)

【特許請求の範囲】[Claims] 発振コイルと共振コンデンサの共振回路を含んで発振回
路を形成し、この発振回路の発振振幅の変化を積分回路
を介して出力回路に導くものにおいて、上記共振回路に
帰還電流を供給する帰還回路をカレントミラー回路によ
り構成するとともにこのカレントミラー回路のミラーす
る方のトランジスタの電流容量をミラーされる方のトラ
ンジスタの電流容量に比し大にしたことを特徴とする近
接スイッチ。
In an oscillation circuit including a resonant circuit of an oscillation coil and a resonant capacitor, and a change in the oscillation amplitude of this oscillation circuit is guided to an output circuit via an integrating circuit, a feedback circuit that supplies a feedback current to the resonant circuit is used. 1. A proximity switch comprising a current mirror circuit and having a current capacity of a mirrored transistor of the current mirror circuit larger than that of a mirrored transistor.
JP15371983A 1983-08-23 1983-08-23 Proximity switch Granted JPS6046124A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP15371983A JPS6046124A (en) 1983-08-23 1983-08-23 Proximity switch

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP15371983A JPS6046124A (en) 1983-08-23 1983-08-23 Proximity switch

Publications (2)

Publication Number Publication Date
JPS6046124A true JPS6046124A (en) 1985-03-12
JPH039650B2 JPH039650B2 (en) 1991-02-08

Family

ID=15568602

Family Applications (1)

Application Number Title Priority Date Filing Date
JP15371983A Granted JPS6046124A (en) 1983-08-23 1983-08-23 Proximity switch

Country Status (1)

Country Link
JP (1) JPS6046124A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62173830U (en) * 1986-04-22 1987-11-05
EP0298329A2 (en) * 1987-07-07 1989-01-11 i f m electronic gmbh Electronic switching device, preferably operating without contact
WO2017001253A1 (en) * 2015-07-02 2017-01-05 Ifm Electronic Gmbh Electronically adjustable inductive proximity switch
CN112859174A (en) * 2021-01-07 2021-05-28 杭州国基数知科技有限公司 Method for preventing proximity switch from being unstable due to vibration

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62173830U (en) * 1986-04-22 1987-11-05
EP0298329A2 (en) * 1987-07-07 1989-01-11 i f m electronic gmbh Electronic switching device, preferably operating without contact
WO2017001253A1 (en) * 2015-07-02 2017-01-05 Ifm Electronic Gmbh Electronically adjustable inductive proximity switch
CN112859174A (en) * 2021-01-07 2021-05-28 杭州国基数知科技有限公司 Method for preventing proximity switch from being unstable due to vibration
CN112859174B (en) * 2021-01-07 2023-09-01 国网江苏省电力有限公司滨海县供电分公司 Method for preventing proximity switch from vibrating and unstably

Also Published As

Publication number Publication date
JPH039650B2 (en) 1991-02-08

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