DE1274183B - Arrangement for contactless switching on one and for switching off the other several electrical circuits - Google Patents

Description

Arrangement for contactless switching on one and for switching off the remaining several electrical circuits The invention relates to an arrangement for contactless switching on one and for switching off the other several electrical ones Circles in which by briefly touching one with an electroluminescent Element and a voltage source connected in series contact a flash of light is generated, which meets a light-sensitive resistor and thereby a switching process initiates.

Bistable flip-flops, which are switched on by a flash of light and remain switched on after the flash of light has died down, are known, for example. B. from German patent specification 1139 545.

It is also known from this to make a light-sensitive resistor optically to be coupled with a light emitting element and when a flash of light occurs thereby switching on a circuit.

The invention aims to provide a way of doing this per se suitable and simple way of influencing an electrical circuit more versatile to use. On the one hand, it is used in particular on wavelength switches in broadcasting or television receivers, on the other hand on keyboards for electronic calculating machines and the like. In the known devices with mechanical wavelength switches or keyboards are proportionate to actuating the switches or keys large mechanical forces are required. Especially with light devices and calculating machines this is perceived as a disadvantage.

The arrangement according to the invention is particularly useful in such devices an advantage that are built up from integrated circuits and therefore special Are small and light and under the actuation of mechanical push button switches force required to tip over. They are characterized by the fact that this photosensitive resistor is optically coupled to the electroluminescent Element and is connected in parallel to a light-sensitive resistor, the is in series with an electroluminescent element and with this through optical Coupling forms a self-holding circuit known per se, that electroluminescent Elements are connected in parallel to the electroluminescent element that these Electroluminescent elements are each assigned light-sensitive resistors which short-circuit the remaining electrical circuits in the conductive state and switch off with it, and that another electroluminescent element is present that is connected in parallel to the electroluminescent element, and the desired switches on the electrical circuit when the flash of light occurs.

Another solution is that the photosensitive resistor is optically coupled to the electroluminescent element and connected in series is with an electroluminescent element that one has a series resistor connected to the voltage source, from the series connection of a light-sensitive Resistance and an electroluminescent element existing, known per se Self-holding circuit is available in which the light-sensitive resistor with the electroluminescent element is optically coupled that a photosensitive Resistance between the voltage source and the point between the electroluminescent Element and the photosensitive resistor is switched and optically coupled with the electroluminescent element that the electroluminescent element is optically coupled with a photosensitive resistor, which is in the conductive State short-circuits the remaining electrical circuits and thus switches off, and that the electroluminescent element or an electroluminescent element electroluminescent element connected in parallel with a light-sensitive element resistance is optically coupled and the desired electrical circuit when the. Light flash turns on.

The invention is explained in more detail below with reference to the drawing. In it, F i g. 1 shows a first embodiment of a wavelength switch according to of the invention, FIG. 2 shows a second embodiment of a wavelength switch according to the invention, FIG. 3 is a block diagram of a so-called full keyboard for a desktop calculating machine, FIG. 4 is a schematic diagram of a so-called simple one Keyboard for a desktop calculating machine, FIG. 5 in cross section a part of a Keyboard or a switch according to the invention and FIG. 6 a variant of the fig. 5.

The wavelength switch according to FIG. 1 contains four similar ones Sections, each made up of six combinations of electroluminescent elements and photosensitive resistors are built up. One of the sections consists from the combinations 1, 2; 3, 4; 5, 6; 7, 8; 9, 10; 11, 12. The electroluminescent Elements are with odd digits, the light-sensitive resistors with even numbers Numerals. The element 1 is in series with the pair of contacts 20, 21 to the Voltage source 15 connected. The elements 3, 5; 7; 9 and 11 are about the photosensitive Resistors 2 and 4 connected to the same voltage source 15.

Each of the photosensitive resistors 6, 8 and 10 is to the Elements 3, 5, 7, 9 and 11 correspond to elements 1 of the other sections in parallel switched. For example, the resistor 6 is to the elements in the top section and the resistor 8 parallel to the relevant elements in the lowest section switched.

The light-sensitive resistor 12 coupled to the electroluminescent element 11 is connected between the base of the pnp transistor 17 and a point of constant negative potential. The collector of the transistor 17 is connected to a control electrode of an effective element in the receiver part 13 . This receiver part is constructed in the usual way and thus contains a mixer stage, an amplifier part, a demodulator and an output stage. The parallel circuit 25, 30 is connected between the receiver part 13 and the preamplifier stage 14. The capacitor 30 is variable and is used to one of the circuits 25, 30; 26, 30; 27, 30 and 28, 30 to tune to the desired frequency in a certain wavelength range. In particular, the circle 25; 30 z. B. tuned in the medium wave range. The capacitor 29 is an isolating capacitor and has a negligible impedance for the signals to be amplified.

The operation of the circuit arrangement is as follows: If the pair of contacts 20, 21 is bridged, e.g. B. in that a finger touches these contacts with very light pressure, the electroluminescent element 1 is made to light up, since the voltage supplied by the voltage source 15 is sufficient to ignite the element 1. The light emitted by this element hits the light-sensitive resistor 2. This makes this resistor conductive, so that such a part of the voltage of the voltage source 15 is available to the electroluminescent elements 3, 5, 7, 9 and 11 that these elements in turn light up. This has several consequences.

Firstly, by exposing the photosensitive resistor 4, the voltage across the elements 3, 5, 7, 9 and 11 is maintained even if the pair of contacts 20, 21 is no longer bridged, causing the element 1 to erase.

Second (as a result of the resistance 12 becoming conductive) the Base potential of transistor 17 reduced. The transistor blocked first 17 becomes conductive, so that the potential of point A increases almost to ground potential. As a result, circuit 25, 30- will be turned on, __ Third, the terminals will be 5, 7 and 9 corresponding elements in the three remaining sections have been deleted since the voltage drop across the resistors coupled to elements 5, 7, 9 6, 8 and 10 (which become conductive due to the irradiation) is greatly reduced, see above that the voltage across the corresponding elements mentioned also decreases sharply. This has the consequence that the transistors 22, 23 and 24 go into the blocked position and the associated circles 26, 30; 27; 30 and 28, 30 are or are switched off.

Analogously to the process described above, one of the circles 26, 30; 27, 30 and 28, 30 are switched on and the other circuits are switched off, when the pair of contacts belonging to the circle concerned is bridged, e.g. B. will by touching the pair of contacts 34, 35, the circle 28, 30 is switched on and the circles 26, 30; 25; 30 and 27, 30 switched off.

To make the activated waveband visible, there is the Possibility of exposing a photocell (not shown) with element 11. This photocell then energizes a relay, which is attached to a suitable location brings the electroluminescent element to light up.

One of the contacts of a contact pair can be formed by a capacitance be e.g. B. by the capacity of the human body to hold a finger is in contact with the other contact.

F i g. 2 shows another embodiment of a wavelength switch according to the invention. In this figure three similar sections are shown, those made up of five combinations of electroluminescent elements and light-sensitive elements Resistances consist of the combinations 1, 2; 3, 4; 11, 12; 41, 42 and 45, 46. The pairs used in the circuit arrangements of Figs. 1 and 2 the same Function are given the same reference numerals.

The element 1 is in series with the pair of contacts 50, 51 to the voltage source 55 connected. Elements 41 and 45 are across the photosensitive resistor 2, the elements 3 and 11 on the one hand via the photosensitive resistor 42 and on the other hand via the photosensitive resistor 4 and the resistor 47 to the Voltage source 55 connected. It goes without saying that elements 3 and 11 or the elements 41 and 45 can be combined into a single element.

The mode of operation of the circuit arrangement is as follows: becomes the contact pair 50, 51, e.g. B. by a light pressure of the finger, bridged, the element 1 lit up. The element 2 is due to the incident radiation conductive. the Elements 41 and 45 connected in parallel light up accordingly on, whereby the photosensitive resistors coupled with these elements 42 and 46 become conductive. Resistance 42 becomes conductive again the ignition of the elements 3 and 11, which in turn ensure that the photosensitive Resistors 4 and 12 become conductive.

As in the circuit arrangement according to FIG. 1 can also be this Differentiate between three parts. First, the transistor 17 becomes conductive and the receiver part (not shown) that corresponds to the circle 25, 30 in Fig. 1 corresponds.

Second, it falls by the photosensitive resistor becoming conductive 46 shows the voltage across the elements corresponding to element 11 in the others Sections away. The transistors 48 and 49 go into the blocked state.

Thirdly, delete element 1 and when no finger pressure is applied thus the elements 41 and 45. This has the consequence, among other things, that the photosensitive Resistor 42 returns to the non-conductive state. The element 3 and thus also the element 11 light up as before, since the element 3 is now on the conductive Resistor 4 and resistor 47 is fed.

In comparison to the circuit arrangement according to FIG. 1 shows the circuit arrangement according to FIG. 2 has the advantage that the number of combinations per section, regardless of the number of sections, is constant in the latter case and increases in the former case. It is easy to understand that in FIG. 2 with n sections the number of combinations 5 n and in FIG. 1 n (n + 2). For n> 3 , the circuit arrangement according to FIG. 2 is that according to FIG. 1 preferable. This is particularly the case with television receivers, in which h = 12 can be.

F i g. 3 shows a section of a so-called full keyboard Calculating machine, for example that section that contains the series of units actuated. The tens, hundreds, etc. sections are structured in the same way.

An AC voltage source 56 feeds the series circuit of an electroluminescent Element 57 and the parallel connection of ten series connections of electroluminescent Elements 60 to 69 and contact pairs 100, 110 to 109, 119. For the sake of simplicity only four of these series connections are shown.

The AC voltage source also feeds via the resistor 59 the parallel connection of a photosensitive resistor 58 and ten similar Combinations of two light-sensitive resistors connected in parallel in series with an electroluminescent element (in the figure four of the ten combinations are shown). In each combination is one of the photosensitive resistors coupled with the electroluminescent element of the combination concerned, while the other resistor is connected to one of those in series with a pair of contacts Elements is coupled. For example, the resistor 91 is with the element 81 and the resistor 71 is coupled to the element 61.

This circuit arrangement has the following mode of action: becomes the contact pair 102, 112, e.g. B. bridged by touching a finger, they light up Elements 62 and 57. The photosensitive resistor coupled to element 57 58 becomes conductive so that the voltage is across the ten similar combinations mentioned above decreases sharply, as a result of which elements 80 to 89 can no longer light up. Of the Photosensitive resistor 72 coupled to element 62 also becomes conductive.

The bridging of the pair of contacts 102, 112 by removal If the finger is interrupted, elements 62 and 57 go out. The properties of the photosensitive resistors 58 and 72 are chosen so that the absolute The size of the resistor 58 increases faster than that of the resistor 72. This leaves achieve each other in different ways. Either the dimensioning or the material of the photosensitive resistors 58 and 72 can be chosen so that the Value of resistor 58 exceeds that of resistor 72, these resistors can be measured under the same lighting conditions. Third, it can be a delaying one Intermediate stage connected between the element 62 and the light-sensitive resistor 72 will. This intermediate stage then consists of one connected to the voltage source 56 Series connection of a photosensitive device optically coupled to element 62 Resistor and an electroluminescent optically coupled to resistor 72 Element.

The deletion of element 62 in these three cases results in that the absolute value of the resistor 72 is always lower than that of the resistor 58 stays. The value of the photosensitive resistor 72 is thus on termination the bridging by removing the finger is still low enough to to bring electroluminescent element 82 to light up.

F i g. 4 shows four sections of a so-called simple keyboard. Each section is connected to voltage source 186 through resistor 184 and is made up of ten parallel branches. Each branch contains the series connection a photosensitive resistor 130 to 139 and an electroluminescent one Element 140 to 149. The connection points of the photosensitive resistors with the electroluminescent elements are via a photosensitive resistor 150 to 159 with the end of the resistor facing away from the voltage source 186 184 connected.

The voltage source 186 is further across the electroluminescent Element 185 connected to the parallel connection of ten series connections, the each of an electroluminescent element 120 to 129 and contact pairs 160, 170 to 169,179 exist. The electroluminescent elements 120 to 129 are each with a light-sensitive resistor 130 to 139 and the elements 140 to 149 each with a light-sensitive resistor 150 to 159 coupled. The last mentioned couplings are indicated in the figure with arrows.

The voltage source 186 feeds and the element 185 controls the bistable multivibrator 182, which in turn controls the ring counter 183.

The circuit arrangement works as follows: If a pair of contacts, e.g. B. 161, 171, bridged by touching a finger, the elements light up 121 and 185 on. The photoresistor 131 coupled to the element 121 becomes conductive. The lighting up of element 185 has the consequence that the bistable multivibrator 182 overturns from one stable position to the other, as this element is in the multivibrator a Gate operated. The pulse sent by the bistable multivibrator leaves the ring counter 183 pass from the ineffective intermediate layer B into the effective position 180, so that one received in the ring counter and coupled to the photosensitive resistor 181 electroluminescent element is made to light up. Resistance 181 becomes conductive. Since the resistor 131 is also conductive, the element 141 receives voltage and lights up. As a result of the coupling of the element with the photosensitive Resistor 151 will maintain the voltage across this element so that it continues to light up, even if the finger pressure on the contact pair 161, 171 ceases to exist. The resistor 131 then changes to the non-conductive state, but the element 151 is now fed via the photosensitive resistor 151.

The opening of the contact pair 161, 171 also has the consequence that the element 185 goes out. As a result, the multivibrator 182 tilts back into the original stable position and in the process supplies the ring counter 183 with a pulse, as a result of which it changes to the ineffective position C.

Then again one of the ten contact pairs 160, 170 to 169, 179 bridged, it is evident that analogous to the manner described above Electroluminescent element corresponding to this pair lights up in the section, the in F i g. 4 immediately to the left of the numbered section is reproduced.

With only ten pairs of contacts it is possible to post a number whose number of digits is equal to the number of sections.

To delete the received number, an additional pair of contacts 190, 191 in series with an electroluminescent element 188 above the supply source 186 attached. Element 188 is optical with a photosensitive resistor 187 coupled across the series connection of source 186 and resistor 184 is attached.

If the contact pair 190, 191 is bridged, the element lights up 188 on, and the resistor 187 becomes conductive. As a result, the tension is lowered over the sections of the keyboard so that the ones still lit up Elements on the keyboard go out. At the same time, element 188 provides the ring counter 183 a pulse, whereby this counter goes into the starting position D.

Fig. 5 shows in section a part of a keyboard according to the invention. On one side of a plate 230 made of non-conductive material with a high dielectric constant, preferably barium titanate, a layer 200 made of an electroluminescent material, a thin, transparent, conductive layer 203, preferably made of tin oxide (SnO2), and a glass plate 201 are applied one after the other. The desired pattern of photoconductive material is applied to the glass plate. On the other side of the plate 230 are parallel strips 210-219 of conductive material (four of which are shown) separated from one another by parallel bars 220-229 of Iosher material. Rods 240 to 249 made of conductive material are attached to the beam. If an AC voltage source 205 is connected between the electroluminescent layer 200 and the grounded rods 240 to 249 and is, for. B. with the finger, the conductive bar 242 is brought into contact with the conductive strips 212, so the part of the electroluminescent layer under the strip 212 is illuminated and the underlying part of the photoconductive pattern on the glass plate 201 is conductive.

F i g. 6 shows a variant. of the section according to FIG. 5. The bars 220 to 229 are made of conductive by insulating spacers 250 to 259 and the rods Material replaced by a somewhat flexible film 260. A slight pressure on the film has the consequence that this film at the point of printing for a moment touches the strip, making the underlying part of the electroluminescent Layer is made to light up.

Claims (10)

Claims: 1. Arrangement for contactless switching on and to switch off the rest of several electrical circuits, in the case of which by a brief Touching an electroluminescent element and a voltage source in series connected contact a light flash is generated, which is a light-sensitive Meets resistance and thereby initiates a switching process, characterized in that that this light-sensitive resistor (2) is optically coupled to the electroluminescent one Element (1) and connected in parallel to a light-sensitive resistor (4), which is in series with an electroluminescent element (3) and with this by optical coupling a self-holding circuit known per se forms that electroluminescent Elements (5, 7, 9) are connected in parallel to the electroluminescent element (3), that these electroluminescent elements (5, 7, 9) are each light-sensitive Resistors (6, 8, 10) are assigned which, in the conductive state, the remaining electrical Circuits short-circuit and thus switch off, and that another electroluminescent Element (11) is present, which is parallel to the electroluminescent element (3) is switched, and the desired electrical circuit (25, 30) when the Light flash turns on (Fig. 1). 2. Arrangement for contactless switching on of a and to turn off the rest of several electrical circuits in which one brief contact of one with an electroluminescent element and one Voltage source connected in series contact generates a flash of light, which meets a light-sensitive resistor and thereby initiates a switching process, characterized in that the light-sensitive resistor (2) is optically coupled is connected to the electroluminescent element (1), and is connected in series with an electroluminescent element (41 or 45) that one has a series resistor connected to the voltage source, from the series connection of a light-sensitive Resistance (4) and an electroluminescent element (3) existing on known self-holding circuit is available in which the light-sensitive Resistor (4) is optically coupled to the electroluminescent element (3), that a photosensitive resistor (42) between the voltage source and the Point between the electroluminescent element (3) and the photosensitive Resistor (4) is switched and optically coupled to the electroluminescent Element (41) that the electroluminescent element (45) is optically coupled with a light-sensitive resistor (46), which in the conductive state the rest short-circuits electrical circuits and thus switches off, and that the electroluminescent Element (3) or an electroluminescent element (3) connected in parallel electroluminescent element (11) with a light-sensitive resistor (12) is optically coupled and the desired electrical circuit (25, 30) when it occurs of the light flash turns on (Fig. 2). 3. Arrangement according to claim 1, in particular for switching a wavelength switch in a radio or television receiver, in which each self-holding circuit from the series connection of one to a voltage source connected electroluminescent element and a light-sensitive resistor consists, characterized in that one of the electroluminescent elements (11) actuates a gate (17) which switches on the electrical circuit (25, 30), and the light-sensitive elements associated with the electroluminescent elements (5, 7, 9) Resistors (6, 8, 10) the electroluminescent element of the other self-holding circuits are connected in parallel (Fig. 1). 4. Arrangement according to claim 2, in particular for switching a wavelength switch in a radio or television receiver, in which each self-holding circuit from the series connection of one to a voltage source connected electroluminescent element and a light-sensitive resistor consists, characterized in that it is in series with that struck by the flash of light light-sensitive resistor (2) lying electroluminescent element (45 resp. 41) optically associated with a parallel to the other self-holding circuits photosensitive resistor (46) is coupled (Fig. 2). 5. Arrangement according to claim 1 or 2, in particular for switching the keyboard of a calculating machine, characterized in that in series with the parallel connection of a number of series connections of a contact (100, 110; 101, 111, etc.) and a light-emitting element (60, is ... mounted 61, 62) an electroluminescent element (57) that is optically coupled with the self-hold circuits connected in parallel with the light-sensitive resistor (58), while parallel to the light-sensitive resistor (90, 91 ...) in each self-holding circuit ( 80, 90; 81, 91 ... ) a light-sensitive resistor (70, 71 ... ) is connected, which is hit by the light flash (Fig. 3). 6. Arrangement according to claim 5, characterized in that that the absolute value of the light-sensitive parallel to the self-holding circuits Resistance (58) greater, preferably at least one order greater than that The value of the light-sensitive resistor (70, 71) hit by the light flash. 7. Arrangement according to claim 1 or 2, in particular for switching a simple keyboard of a calculating machine, which device consists of a number of parallel sections each containing a number of self-holding circuits, characterized in that in each section of the connection point of each of the self-holding circuit forming a series circuit electroluminescent element (140 to 149) and a light-sensitive resistor (150 to 159) via a light-sensitive resistor (130 to 139), which is hit by the light flash and which is separate for each self-holding circuit, is connected to a common light-sensitive resistor (181), which is connected by an electroluminescent element ( 185), which is connected in series with the parallel series connections of a contact (160, 170; 161, 171 ... ) and a light-emitting element (120 to 129) to the voltage source (FIG. 4). B. Arrangement according to Claim 7, characterized in that the electroluminescent Element connected in series with the series connections connected in parallel to the voltage source is connected, a bistable multivibrator (182) controls, which in turn a ring counter (183) provides pulses, whereby the common light-sensitive Resistances (181) of the sections through successive brief contacts of the contacts are illuminated one after the other (Fig. 4). 9. Optoelectric network for an arrangement according to any one of claims 1 to 8, which comprises a plate of non-conductive Contains material with a large dielectric constant, on one side of which one after the other a layer of electroluminescent material, a transparent conductive layer and a glass plate provided with a pattern of photoconductive material are characterized in that strips are made on the other side of the plate conductive material (210 to 219) are attached; by bars (220 to 229) are separated from each other by insulating material, while bars (240 to 249) made of conductive material are applied (Fig. 5). 10. Optoelectronic network for an arrangement according to one of claims 1 to 8, which contains a plate made of non-conductive material with a large dielectric constant, on the side of which a layer of electroluminescent material, a transparent conductive layer and a glass plate provided with the pattern of photoconductive material in succession are applied, characterized in that strips (210 to 219) of conductive material are attached to the other side of the plate, which are separated from one another by bars (250 to 259) made of insulating material, while a flexible film (26Ö) is made on the bars conductive material is attached (Fig. 6). Documents considered: German Auslegeschrift No. 1139 545.