DE2112521A1 - Electronic command generator - Google Patents

Description

Electronic command generator

To trigger work processes on machines and production facilities, manually operated buttons are often required. that operate one or more electrical contacts. Particular care is required where the work cycle of the machine is can be dangerous for the operator, e.g. on cutting machines for paper and other materials, or also on punching and pressing. Machines and production facilities that show a "dangerous cycle" in their work cycle » must therefore be provided with a special safety device. The "two-hand indentation" should be emphasized here Punching and pressing, as well as the protection of presses with so-called "light curtains", e.g. according to OBP 1221927. With light curtain protected presses are often provided with an additional Tip switching triggered.

All buttons or to be triggered by a mechanical movement levers also have the disadvantage that such devices can be manipulated, so they can be "cheated". Through the Most of the usual piece-rate work is done to advance payment. Often the canoe can be done by hand with little effort Movement, i.e. the actuation of a button or lever, e.g. by means of a cord, can be transferred to a FuD, which then makes it faster can be worked until at elnor a certain phase of fatigue Accident occurs. Such work is contrary to the regulations, but is practiced again and again.

BATH ORIGINAL

209839/0969

2Ϊ12521

Another disadvantage of all operated by a mechanical movement Triggering devices consists in the fact that work is required for triggering itself, as a result of which the operator becomes tired. It is true that they are non-contact electrical Known buttons that produce an output signal when a hand approaches but these non-contact keys also give an output when other materials, especially metal, come close * signal, can therefore be easily manipulated again.

The invention relates to an electronic proximity switch as a safety command device that only works when a hand approaches or another part of the human body, but not when approaching other materials, such as metals of all kinds, wood, plastics, paper, textiles, leather, glass, etc. Um To force actuation by hand, the installation of the button only needs to be designed in such a way that it is connected to another Part of the body, e.g. the elbow or knee, cannot be reached, e.g. this is possible by installing it in a recess.

This object is achieved by the combination of a inductive and a capacitive probe, whose sensor systems are nested and whose fields penetrate one another, solved to a "hand button".

2098 39/0969

A. Inductive button speaks when approaching all metallic ones Objects on, the response distance is of the metal type, as well depends on the dimensions of the metal part. Inductive proximity switches can be designed to be very sensitive and constant.

Capacitive buttons respond to practically all materials. The sensitivity is strongly influenced by the properties and depending on the dimensions of the approximated matter. The greatest response distance is achieved with electrically conductive bodies.

According to the invention, in the combined "manual button" the Sensor systems of the inductive and capacitive buttons are nested in one another in such a way that the fields, that is, a preferably magnetic - and a preferably electrical alternation - field, penetrate.

The capacitive button must be so insensitive. have been set so that or only responds to large, electrically conductive bodies, i.e. yB when a human hand approaches. Such a capacitive button naturally responds to the approach of metal parts, but not to the approach of wood, plastics, leather, paper, glass, textiles, etc. The sensor system of the capacitive button is in accordance with the invention in the sensor system built-in inductive button, which in turn

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responds to the approach of all metal parts. According to the invention, the response distance of the inductive button is set so that when a metal part approaches, the inductive button always responds at a greater distance than the capacitive button.

If a metal part is approached to the manual button, an output signal appears at the output of the capacitive button AND at the output of the inductive button.

If a plastic part or wood, glass, leather, paper, etc. is approached to the hand switch, no output signal appears either at the output of the capacitive switch or at the output of the inductive switch.

Is a hand closer to the hand button, ao an Au appears at the output of the capacitive probe β transfer signal, while no output signal appears at the output of the inductive probe.

If the inductive button and the capacitive button according to the invention are followed by a logic that gives me an output signal when there is no output signal at the output of the inductive button, while at the same time there is an output signal at the output of the capacitive button , this means that the output of the manual button then and only then an output signal

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appears when a hand is close to the button. The approach of all other materials listed cannot be output from the Trigger the hand button.

The invention is explained in more detail below with the aid of examples, wherein all features are essential to the invention on their own as well as in any combination with one another.

Pointing from the drawings

Fig. 1 ι the mechanical structure of the Fühlersysteins one Execution example of the manual button after the Invention,

[j .: ? ¹ ITIfJ 3ί Variants of the mechanical structure of the sensor «? Systems of the hand window.

'»: A block diagram of the manual button mj f of the internal logical connection of the outputs of the inductive and capacitive button.

; ϊΆη Block diagram of a variant of the manual button.

S ig, L : Di «<Ί fkti-1 'i-'hf ¹ ^ cKaI fuug clnfs TastTS after Fi ^ j. 5 · I if.;, 7 ijji'l b: Ab (ji »," nderto circuit details 1 s einos liand-Tastors ■

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6 2) 12521

As can be seen from Figure 1, the hand switch according to the invention is built into a metal housing 1, which can be grounded. This measure eliminates side effects so that it can be installed flush in a cast construction or in the metal cover plate of a control panel. This housing 1 should be made of a highly electrically conductive metal, for example aluminum. However, it can also be made of steel with an inner lining of copper or aluminum. According to the invention, the inductively acting sensor system consists of a U-shaped HF iron core 2 on whose legs the windings are arranged. In connection with an HF oscillator not shown in FIG. The capacitively acting sensor system consists of a metal coating k _t which is arranged on the underside of the cover plate 5 made of insulating material, the metal housing 1 acting as a counter electrode. In connection with electronics, also not shown in FIG. 1, the capacitively acting pushbutton is hereby formed. According to the invention, the sensitivity of the inductive button to a highly conductive metal must always be greater, the sensitivity of the capacitive button to a human hand.

Fi {j.2 shows a different geometry of the sensor systems of a button & oniäß the invention, whereby for mutatis mutandis the same components the same designations were used. The HF iron core S is formed here as an open cross core, on its four legs the windings 3 are arranged. The interconnection of each

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Windings 3 can be made so that poles of the same name arise next to one another or opposite one another; both versions, which differ in their field lines, are practically useful. An excellent nesting of the fields is achieved by the embodiment of the sensor systems of a hand-held button according to the invention shown in FIG. As RF iron core is here one half of a known ⁿ Schalenlcernes "2 use. On the middle bleb this pot core half is arranged, the winding 3. The alternating electromagnetic field generated thereby is rotationally symmetrical. The capacitive g sensor system consists of an annular disk k from a good electrical conductor Metal, especially copper, which has a slot 6. The metallic housing 1 in turn acts as the counter-electrode, so the alternating electrical field, which is preferred, is also rotationally symmetrical.

A Elockschaltbild a hand-held probe is shown as a possible embodiment in Fig. K. As an arbitrary assumption, the inductive button as well as the capacitive button should show a ZERO signal at the respective outputs in the non-addressed state, which in the addressed state changes to the pin L-signal · The inductive button consists of the inductive sensor system 7 with additional evaluation electronics P, the capacitive sensor system consists of the capacitive sensor system 9 with subsequent evaluation electronics. The output of the inductive evaluation electronics B 1 st with an NOT-GIi ^ d 11 connected. The output of the capacitive evaluation electronics 10 and the ^Atlt VHtt% | A ^ / ^ £ yXr member 11 work on an AND member 12.

BAD OWGLAL

At the output of the AND element 12, the L signal can only appear if a hand approaches the pushbutton according to the invention, what should be shown here briefly »

If a metal part approaches the combined sensor system 7 »9, an L signal appears at the outputs of both evaluation electronics 8 and 10. Since the output signal of the axis value electronics 8 assigned to the inductive Fühlersyetem 7 is inverted by the following NOT element 11, there is a ZERO signal at input 13 of AND element 12, while input 1 * i has an L signal. A ZERO signal therefore appears at the output 15 of the AND element 12.

If a part made of plastic , wood, glass, leather, paper, etc. approaches the combined sensor system 7 »9, a ZERO signal appears at the outputs of both evaluation electronics 8 and 10. The output signal from 8 is negated by 11, so that the input 13 of the AND element 12 has an L signal, while the input 1 U has a ZERO signal. At the output 15 of the AND element 12, ZERO signal 1 appears again.

If a human hand approaches the combined sensor system 7 »9, a ZERO signal appears at the output of the evaluation electronics 8 assigned to the inductive sensor system 7, which is inverted by the NOT element 11, so that L at the input 13 of the AND element 12 Signal appears. At the output of the capacitive Fühlprsystem Q

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209839/0969

associated evaluation electronics 10 appears L-signal, so also at input 1 ^ of the AND element 12. Since when a hand approaches L-signal is seen at both inputs 13 and 1 ^ of the AND element 12, Only in this case does output 15 also carry an L signal.

If the hand is protected by a sturdy leather glove, As it is often worn in sheet metal processing, the fields of the combined sensor system reach through the leather glove through it, so that the button also emits an L signal in this case, which is what it should.

Inductive and capacitive buttons work with high frequencies in the range from a few 10 kHz to a few MIiζ. Build the inductive Button according to the so-called "0sz1 llator damping principle" atjf, according to the invention, a very considerable reduction in effort can be carried out by the following measure:

An inductive button based on the oscillator damping principle is constructed in such a way that the interchangeable pin generated by a coil in the LC oscillator can emerge freely on one side of the coil. Spul Pn-- or, Kp rna no rdnuiiß en ₍ which allow dip?, Eirid shown in Fij.1 bM Ί . Is oin Metallt'-il dir> * "w ί r) (] η iifjp nM Im rt-, in ..- f »rd *? n in this subject part ril'hi'l · t. romani ¹ " Γ / oiigt, the Os- 'i 1 1 ι L'T id H thus energy ent- / ^r i ;; r > i ', II1 rrdn rrh v «rr i ri _; '; ort ^ i rl i <ί size nev positive feedback

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whereby the oscillation amplitude decreases. When the metal part comes closer, the oscillator stops completely.

According to the invention, the output voltage of the LC oscillator is used of the inductive button used to supply the capacitive button «Since all capacitance converters in their linear Area of relationship:

Λ = k "U" w "C. .

obey, where:

A is the output quantity, direct current or direct voltage

k a constant '

U is the amplitude of the feeding AC voltage

<X> the angular frequency

C mean the capacity

With this measure, you can limit yourself to the electronic evaluation of the output signal of the capacitive button alone. When a large metal part with λ / λ = attenuation approaches, eg iron, the os? I 1 latoraniplitude collapses quickly, so in the above equation U becomes zero, which means that ? Λ \ .zero; If one locates a small metal filament in.it goriiitjor jjfiinpfu-nrpw: rkunfj, ^ * U. Kupfer, then takes; The voltage LT drops sharply, which greatly disturbs the ability of the controller to be filled. So the trap occurs? Effect: a.

2098 39/0369 bad original

FIG. 5 shows the block diagram of this arrangement, according to FIG Invention. For the sake of clarity, in this illustration the inductive and capacitive sensor systems are shown spatially distant, here too, of course, there is a geometry to be selected according to FIGS. 1 to 3.

The inductive sensor system consisting of a coil and an open HF iron core 7 is supplemented by the capacitor 16 to form an oscillating circuit, which together with block 17 forms an oscillator. This gives the inductive button with the properties described above realized. On the core of the inductive sensor system 7 iat a winding 18 applied, one end to the capacitive Sensor ^ 'p-t.om 9 is connected. Downstream is a Capacity? -St rois-, or voltage converter 19t its output on a trigger circuit 20 works. A pin relay, for example, can be connected directly to the output 21 of this arrangement.

Figure 6 serves as a possible embodiment of such a circuit. Dor LC Oazi Π ator consists axis transistor 22 whose Knilektor is connected to ^ i nor the coupling winding 23 dee inductive sensor system 7, D <* r actual i "" Schvriiigkrp is-by dio winding 2 ^ and d "n Koudensn to * - 16 formed. Di ^. Mitkopplung prf ⁿ lj !, iibor- ii'c- Vi rl "! ^{Ung T 1} ? Ur.d the Vidor ^ tand ' ¹ ^ t ^ ^{o: r} v-ur Einstel-1 HIi ₁ ¹ J (If -S Mi tknj'j. 1 nngsf aktor? Di "nt. The capacitor 27 causes

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only a galvanic separation. The resistors 28, 29 and serve to set the operating point of the transistor 22, the capacitor 31 becomes the base of the base cha lt \ jng working transistor 22 is connected to ground in terms of AC voltage.

The capacitive sensor system -9 is connected to one end of the winding 2h . The actual capacitance converter is implemented in the example by a diode module, which consists of the diodes 32 and 33, the resistor 35 and the capacitor 36 . By means of the capacitor 37 tst- the base point of the diode pump is connected to ground in terms of AC voltage. This diode pump is connected to a tap on the winding Zk , the upper end of which is connected to ground via the trimming capacitor 38. The initial capacitance of the capacitive sensor system 9 can be neutralized by means of this capacitor 38. The diode pump is followed by a filter element consisting of the resistor 39 and the capacitor kO. The direct voltage obtained in this way is connected to the non- inverting input of an operational amplifier h 1, which is fed back by means of the resistors k2, +3 and Hk , that is to say shows a trigger behavior. The inverting «? The input of the operational amplifier 'ί1 is connected to the center tap of a potentiometer h6 via the resistor '15, which is necessary for reasons of offset compensation, whereby the swell of the trigger can be set. The Zenerdiödfm • '17 lind '(^ diener, together with the series resistor for stabilizing h $ df »r V ^r f) i ^v florgungRspanmingen the circuit. At the exit of the Trtjjg'nrs there is a range of resistance between 0 and 51 existing. Via which you base the switching ■

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sistor 52 is controlled. This transistor can, as shown, control a relay 53 directly, the diode 5h then serves to cut off inductive voltage peaks.

Instead of the diode pump shown in FIG. 6, another converter circuit can also be used. 7 shows such an embodiment, the circuit details. This converter circuit, which works as an actual current generator, is in turn connected to a tap on the winding 2k and consists of the diode 55 and the transistor 56 with a downstream integrating capacitor 57.If the initial capacitance of the sensor system 9 is neutralized by the capacitor 38, the output current of the circuit follows 7 of the change in capacitance that occurs when a body approaches

'* "' ¹ ^ '■ i ■' * '*' i" ⁱ * · '° ύ ^ ^r ' i ^ i ~ fv ^r ^ '
to the probe · 9 arises, directly "proportional. The following

Electronics must of course be adapted to the converter.

In order to make it easier to adjust the device, according to the invention a phase-dependent rectification of the output voltage of the

proposed capacitive sensor system. An example of this is shown in FIG. The neutralization circuit, formed by part of the winding 2h and the capacitor 3R, creates a diagonal voltage directly at the input diode 55 dps CI converter. Based on nine, through the kajfazi tIvρ l · ü! "Rsystom 9 orznugte Wechsfilapannung at the input of the converter f-rfährt, these b ^ i a ^r 'bf * rkoiupensati on by the Kondonsator' JH ei non Phnspiisprung. By phasenabhängi ge Gleichriolituttfj \. 1 rd: »I so for dio W ^ itßrve rarbei tiing pine through Hberi on or / eugte alternating voltage uritordrilckt, at the collector

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of the transistor 56 can only appear a half-wave which, after processing by the transistors 58 and 59j, for which the resistors 60, 61, f> 2 and 63 are required, is fed to an input of the AND element 6h. A half-wave of the oscillator is fed to the other input of the AND element 64. An alternating half-wave can only occur at the output of 6h if the input voltages are in phase.

BAD QRUälNAL 209839/0969

Claims (1)

Claims . )) Contactless acting electronic command generator, characterized in that this only
by the approach of a human body part, in particular a hand, responds. 2.) Electronic command generator according to claim 1 characterized in that it has a - electric alternating field working sensor system (9) and one with a magnetic
Has an alternating field working sensor system (7). _. 3.) Electronic command generator according to claims 1 and 2, characterized in that the two
Sensor systems are nested in one another, and that their fields penetrate one another. Electronic encoder according to Claims 1 to 3, characterized in that the sensor systems (~) and (9) together each have an electronic Circuit form an inductive and a capacitive button, whereby the response 209839/0969 BATH ORIGINAL Patent claims " -Distance of the inductive probe greater than 1st, .ils the response distance of the capacitive button, in relation to bodies with good electrical conductivity. .5.) Electronic command generator according to claims 1 to h, characterized in that the sensitivity of the capacitive button is set so that it only responds to electrically conductive bodies. 6.) Electronic command device after at least of the preceding claims, characterized in that it is in a housing (i) from electrically conductive material that may be grounded. 7 «) Electronic command generator according to at least one of the preceding claims, characterized in that the alternating magnetic field is generated by an inductive sensor system, the coils (3) of which are arranged on a U-shaped core (2), between the legs of the active document (H) a capacitive sensor system, which circles on the dip influence of an alternating electric field, arranged '.1st. BAO ORIGINAL 209839/0969 8.) Electronic command gate after at least one of the preceding claims characterized in that that the capstans of the inductive sensor system a cross-shaped HF iron core with high-exogenous Legs, as shown in Figure 2, are arranged, between the four legs of the active Document (^) of a capacitive sensor system arranged is. 9.) Electronic command generator according to at least one of the preceding claims, characterized in that the coil of the inductive sensor system is arranged on the central portion of half of a shell core, as shown in Figure 3, and that the active document (^ i) one capacitive sensor system «? is annular over the winding and has a slot (6) on 51. 10.) Electronic failure generator, at least one: the previous claims characterized rtni dl η output « ¹ 'it *»? i ndukt-1 νβη T; i "tP ^{r <} i and the knpa / i tive button?» In rlor Ku i "o lnjisfih linked« ifnd, daii dor ο] ektron i srhfi Dcfnhi qgnhi qgnber me and only flsnn fin output. "» signal emits when the axis of the capacitive button has an output signal ibgibfc and 20S839 / 0969 BATH ORIGINAL Claims ■ * - * - * I the output of the inductive button has no output signal gives away. 11.) Electronic command generator after at least one of the preceding claims characterized dall the oscillator of the inductive button also serves as a voltage source for the capacitive button. 12.) Electronic command generator according to claim 11 and at least one of the preceding claims, characterized in that only the output signal of the capacitive button? is used electronically. 13 ·) Electronic command transmitter after at least one of the preceding claims characterized in that that for signal evaluation of the capacitive button Capacity-current converter (1P) e.g. a diode "- jvu nipp provided 1st, which a trigger Ehr1 txmg (20) follows. ". H . ) El fktroni scored response givers according to at least one of the previous Atispriiche characterized in that the initial capacity of the capacitive! F'ihlor- 209839/0969 bäb original Claims A3 systems is neutralized. 15 ·) Electronic command device after at least one of the preceding claims, characterized in that the capacitive sensor system has a phase-dependent Rectification is connected downstream. 16.) Electronic command generator after at least one of the preceding claims, characterized in that the response threshold of the trigger (20) can be changed is trained. 1? ·) Electronic command device after at least one of the preceding claims characterized in that that the positive feedback factor of the alternating voltage generator is designed to be variable. 209839/0969 BATH