CH658735A5 - Device for identifying an information. - Google Patents

Description

658735

PATENT CLAIMS

1. Device for identifying information which is assigned to a key part (2) with the aid of reading means which are arranged on a lock part (1), the information being encoded in a first information carrier (E2) in the key part (2) , the key part (2) also has a receiving element (L2) and a signal transmitter (S2) which can be influenced by the first information carrier (E2) and the lock part (1) also has a receiving element (LI)

and has an evaluation circuit containing a second information carrier and contains an energy source (G) which can be energetically coupled to the receiving element (L2) of the key part (2) for the purpose of transmitting the energy for activating the components of the key part (2) and actuating it of the first information carrier (E2) in such a way that the signal transmitter (S2) emits an information signal characterized by the information from the first information carrier (E2), which is received by the receiving element (LI) in the lock part (1) and in the evaluation circuit with the reference information of the second Information carrier is compared, and the evaluation circuit emits a characteristic output signal if the first and second information have a predetermined relationship to one another, in which device the lock part (1) contains an oscillator (G), at the output of which a first coil (LI) is located, and the key part (2) has a second that can be coupled to the first coil (LI) e coil (L2), characterized in that the first coil (LI) forms the receiving member of the lock part (1) and the second coil (L2) forms the receiving member of the key part (2) and that elements of the key part (2) and the The lock part (1) together form an inductively coupled switch, the signal transmitter (S2) being set up to cause a more or less complete short circuit of the second coil (L2) or to apply energy to the signal of the second coil (L2), so that there is a change in the signal curve both at the side of the second coil (L2) and at the first coil (LI) at times which are determined by a coincidence of counting events.

2. Device according to claim 1, characterized in that a short circuit via a diode (Dl) can be produced on the second coil (L2).

3. Device according to claim 2, characterized in that an electronics unit (E2) is installed on the key side, which interrogates and counts the half-waves of the signal which are passed through by the diode (D1), this electronics unit containing the first information carrier with the information of which is determined at what times a switch (S2) short-circuiting the second coil (L2) becomes effective.

4. The device according to claim 1, characterized in that for short-circuiting the second coil (L2) this is connected via a short-circuit switch (S2) an uncharged capacitor (Cl).

5. Device according to one of claims 1 to 3, characterized in that in the lock part a third coil (L3) is arranged spatially separate from the first coil (Ll) so that the electromagnetic influence of the second coil (L2) on the third coil (L3) disappears.

6. The device according to claim 5, characterized in that the inductances of the first and the third coil (LI, L3) are tuned via variable resistors (RI, R3) so that these coils (LI, L3) at comparable measuring points (A, B) have no phase shift in their signals, and that these in-phase signals are fed to an operational amplifier (OP1) with differential inputs, which emits the difference between the two signals as the output signal (C).

7. The device according to claim 6, characterized in that the variable resistors (RI, R3) are designed as voltage-adjustable resistors.

8. The device according to claim 1, characterized in that a charge-carrying capacitor (Cl) can be connected to the second coil (L2) via a short-circuit switch (S2) controlled by electronics (E3) (FIG. 7).

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DE-A 2 657 182 discloses a device for identifying information which is assigned to a first carrier component (key part) with the aid of reading means which are arranged on a second carrier component (lock part), the information being in a first Information carrier is encoded in the first carrier component, the first carrier component also has a receiving element and a signal transmitter that can be influenced by the first information carrier, and the second carrier component also has a receiving element and an evaluation circuit containing a second information carrier and is connected to an energy source that is connected to an energy source Coupling with the receiving member of the first carrier component can be brought about, for the purpose of transmitting the energy for activating the 25 components of the first carrier component and actuating the first information carrier in such a way that the signal transmitter has an In characterized by the information of the first information carrier Outputting formation signal, which is received by the receiving element in the second carrier component and is compared in the evaluation circuit with the reference information of the second information carrier, and wherein the evaluation circuit outputs a characteristic output signal when the first and second information have a desired relationship to one another.

35 Essential features of the aforementioned device include seen in the fact that a) the receiving element in the first carrier component is assigned an energy evaluation stage which initiates activation of the first information carrier only when the received energy exceeds a minimum value,

b) supplementary parts of an electronic signal generator are provided in the first and second carrier components,

c) the electronic components of the first carrier component are frequency and / or amplitude-determining circuit components of the signal generator,

d) the first carrier component contains an oscillator, at the input of which there is an impedance (coil) and the second carrier component has a second impedance (coil) that can be coupled to the first impedance, and e) the impedances (coils) contain ferrites and are designed as ferrite antennas .

With this known identification device implemented in a lock-key combination, the 55 following problems between lock and key remain open, namely that

1) a signal stamp on the key side must be recognized on the lock side,

2) the signal must be impressed on the key side at exactly 60 predetermined times so that the

Lock side can concentrate exclusively on these times and the lock side is synchronized in the signal detection with the signal appearance times and

3) Coded signal stamping must take place on the key side 65.

The inventive device with which these problems are solved is defined in claim 1.

A short circuit can preferably occur at the second coil

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3rd

658 735

can be produced via a diode, which affords the advantage

that depending on the circuit of the diode, a half wave. e.g. the positive, is not short-circuited, but is available for counting the pulses, which makes it possible to close a key-side switch exactly at a point in time which is predetermined by the signal generation on the lock-side coil.

In this case, electronics can be installed on the key side, which interrogates and counts the half-waves transmitted by the aforementioned diode, said electronics containing the first information carrier, with the information of which it is determined at which times the switch short-circuiting the second coil becomes effective.

Embodiments of the device according to the invention are explained below with reference to the drawings.

Fig. 1 and Fig. 2 each show an inductively coupled switch that can be used in the device.

3 and 4 show, as exemplary embodiments of the device, a lock-key circuit, each of which contains an inductively coupled switch and is completed with the electronic elements already mentioned.

5 and 6 show signal waveforms, and

Fig. 7 illustrates a circuit for energy application.

In the circuit according to FIG. 1, a periodic signal is passed through a generator G via a resistor R1 and a coil LI. These components G, R1 and LI belong to the lock side when the circuit is used in an electronic lock and key combination. A coil L2 assigned to the key side is coupled to the lock-side coil LI, so that the corresponding signal curve U1 or U2 results with a phase shift on both coils. If the coil L2 is short-circuited via the switch S2, there is not only a change in the signal curve on the coil L2 side, this short circuit is also detected on the coil LI at point S1. The associated signal curves can be found in the drawings attached to FIG. 1. The circuit is therefore an inductively coupled switch in that the actuation of the switch S2 also has an effect on the coil LI via the inductive coupling.

Another type of this switch results if there is a change in the coupling ratio between the coils LI and L2 by moving the coils apart or by pushing a corresponding material M between the coils. In this way, the function of the switch S2 could be activated or deactivated. The switch would therefore depend on the coupling ratio. It would then be an inductive coupling switch.

As can be seen from the signal curve in FIG. 1, the signal U2 disappears for the time in which the switch S2 is short-circuited. If it somehow succeeds in short-circuiting the signal at switch S2 in such a way that counting of the signals at S2 is not interrupted at the same time, then it is possible to / synchronize the signals. It is possible in this way to close the switch S2 on the coil L2 side after exactly the n-time return of the signal Li 1 on the coil LI side.

If the short circuit on the coil L2, as shown in FIG. 2, is carried out via a diode D1, this goal can be achieved. In this case, for example, the positive half-waves of the signal are not short-circuited, so that they are available for counting. If the positive signal waves are counted on the coil L2 side, the switch S2 can therefore close exactly at a point in time which is predetermined by the signal generation on the coil LI side.

If the frequency 5 is changed on the signal generator G side, the frequency on the side of the switch S2 also changes, but the counting of the positive half-waves remains unchanged, so that there is still exactly the same wave crossing, but with a different time difference between the switching events , is switched.

An exemplary embodiment of the device according to the invention is shown in FIG. 3, which shows the addition of electronics E2 to the circuit of FIG. 2.

This electronics is used to interrogate and count the positive half-waves of the key circuit, for example, via point S3. The electronics E2 contains coded information in an information carrier with which it is determined when the switch S2 is short-circuited. Of the two waveforms, it is now no longer the one of the lock circuit that determines the key circuit. 20 A short circuit occurs at a certain point in time (after n positive half-waves of the signal). which can be proven late by AT t. With this principle, the signals that appear on the key side can be detected completely synchronized at S1 and thus 25 can be recognized. The lock-side circuit contains an evaluation circuit (not shown in FIG. 3) which contains a second information carrier, which compares the information shown at the time of closing the switch S2 with the reference information of the second information carrier and emits a characteristic output signal if the two information have a predetermined relationship to one another .

In addition, there is the component El, which turns the AC signal into a DC voltage signal. With this component, the supply power is generated on the key side. Here, too, it is advantageous to note that only the one half-wave is cut off briefly, so that no lasting drops in energy supply are noticeable.

The circuit shown in FIG. 3 can be improved further, with the aim of being able to use the signal in a more concise manner as a carrier of information. According to the circuit of FIG. 3, the signal generated by short-circuiting is superimposed on that of the signal generator, and the task now is to separate this signal from the basic signal of the signal generator in a more unambiguous manner.

Basically, two ways would be conceivable for this. Corresponding signal manipulations can be carried out on part 2 as well as on part 1. Any additional effort involved in moving is problematic. part (here the key part 2) must be driven. All additional manipulations on this part for better signal transmission increase the number of components, thereby increasing energy consumption and space. Additional effort should therefore only be taken on the part that allows this due to its spatial structure. In general, however, the following explanations can refer to both part 1 and part 2. 60 The problem solution presented here assumes

that in part 1 a second coil L3 is attached spatially separated from the coil LI in such a way that the electromagnetic influence of the coil L2 on the coil L3 does not come into play. If the coil L3 is connected in a suitable manner in terms of circuitry to the coil LI in such a way that the basic signals applied to them are completely the same, then all deviations from this equality can be clearly detected by means of a differential amplifier.

658 735

4th

The problem solution is outlined in FIG. 5 shows the signals at points A, B, C as they result when part 2 is not in the vicinity of part 1. The inductors LI, L3 are matched via the resistors RI, R3 in such a way that they have a phase shift in their signals at points A and B. As a result of the difference between the signals A and B, which is at the input of the operational amplifier OP1, the signal curve C results as the output signal of the operational amplifier.

If Part 2 is now approaching Part I, the total inductance due to the inductors LI and L2 now in the vicinity will change the signal curve A so that when the resistors R1 and R3 are properly matched, the signals A and B overlap exactly - or if so Coils LI, L3 are wound in opposite directions, are 180 ° out of phase. At the output of the operational amplifier, due to the disappeared difference between signals A and B, no signal will appear at its input. The C line will be identical to the O line (or have a constant value). This changes for the moment switch S1 is closed. The coil L2, which receives its energy from the coil LI when the switch is open and accordingly builds up a voltage across the resistor R2, is short-circuited, there is a field breakdown which immediately affects the coil LI, and the signal curve as it appears at the Point ts is shown in FIG. 6. The coil L3 in part 1 remains unaffected by this change as a result of the switch change in part 2, since it is spatially far enough from the coil LI.

6 shows the process accordingly. The two courses of curves A and B from FIG. 5 are merged into one curve in FIG. 6. Only at point ts (the time at which switch S1 is closed) is there a brief difference between the two signals. This changes the input signal of the operational amplifier, which outputs the signal, amplified accordingly, in the form of the curve C at its output. This signal is such a clear representation of the switch change of S1 that it can be processed electronically without major difficulties.

The coordination of the circles in parts 1 and 2, or their adaptation to one another, can also be carried out automatically, in that the resistors RI, R3 are designed as voltage-regulating resistors. In this case, the output signal of the operational amplifier is used to change one of the resistors until the output signal has reached a minimum value.

Instead of the short-circuiting of the key-side coil L2 by the switch S1, a synchronous switch can also be effected by an additional load on L2 by means of an uncharged capacitor which is connected to the coil by means of a switch, although it should be borne in mind that the capacitive short-circuit caused by a Switch closure caused the greatest conceivable load is not to be equated and that the known, temporally exponential decrease in the effect of the capacitive short circuit in connection with the manufacture of a synchronous switch cannot be used.

In contrast, a supply of energy, which is stored in a charged capacitor, represents a further possibility for a synchronization measure to be effected via the influence of the coil. The capacitor is connected to the coil by means of a switch, the switch-on times being effected by the known measures of is synchronization , for example a count of the half-waves, can be determined.

FIG. 7 shows the principle of the synchronous switch aligned with energy supply in one exemplary embodiment. Then an additional capacitance is added to the key circuit 30, which is applied to the inductor L2 via the short-circuit switch S2. The actuation of the short-circuit switch S2 is controlled via the electronics E3, so that at a suitable point in time the amount of charge which is on C1 closes via the inductivity L2 and, as a result of the current flow, has an effect on the lock coil L1 becomes. It is obvious that this type of short circuit does not destroy energy, but rather the energy that is present in Cl is briefly supplied. This energy supply which occurs at the point in time 11 can be seen from the resulting peak in the curve of FIG. 7a.

B

5 sheets of drawings