DE2705827A1 - Electronic locking system with generator key - has frequency modulated carrier wave generator working with signal discriminator circuit - Google Patents

Abstract

The electronic locking system has a key with a generator producing a large number of frequency-modulated carrier waves, and to which a first induction unit is electrically connected. A lock has a second such unit inductively coupled to the first when the key is in a predetermined position in relation to the lock. A signal discriminator circuit is connected in the lock circuit and compares a predetermined sequence of binary signals with that in the generator carrier wave. If they tally, a drive moves the lock between the engaged and the free position.

Description

Keyhole free electronic lock

The invention relates to an inductively couplable with a key Lock in which the key sends a binary signal to the lock and this only is unlocked on a specific signal.

Electronic lock systems are known in the most varied of forms become. In general, the key or a coding device is placed in an opening of the lock part of the system one leads. The lock then distinguishes the predetermined one Code of all other possible codes. In the special case of electronic locks, the key can be encoded in any way. With some known types of coding punched holes are provided, which are assigned electrical buttons in the lock are. Furthermore, conductor strips are used, with the help of which electrical circuits be closed in the castle. Other methods use a circuit of the Lock an electromagnetic code of the key is scanned.

A known electronic lock system uses a key a coil. If the key is placed in the immediate vicinity of the lock, so this completes a circuit contained in the lock, the lock opens.

However, such systems are complicated and to purchase and Maintenance expensive. Electronic locks have a number of known advantages. the known electronic lock systems, however, also have certain disadvantages.

On the one hand, electronic locks require a power source.

In a large number of known locks, the power source is in the lock part included in the system. For certain applications however, it is unsuitable and impractical, especially if the power source or the lock is not accessible.

Some known electronic lock systems are constructed so that a large number of replaceable or re-encodable keys relative to one small number of locks. Such locks contain complicated ones Mechanisms including an energy source. However, such systems are unsuitable and useless if one key fits several locks and the locks are exposed to abusive treatment as well as are located at which they cannot be supplied with energy.

Other problems arise from the clogging of keyholes with electronic lock systems. The introduction of foreign bodies into the keyhole a complicated electronic lock can be some conventional electronic Severely damage or even destroy locks, as this will contaminate the contacts or the electromagnetic sensors are destroyed. Destruction by such a thing Every lock that is accessible to the public is subject to clogging.

Another problem arises when transmitting an electrical signal from the key to the lock, because when using a single signal form the The number of different types that can be used is severely limited. Since in addition Parts of electronics, especially those that control the shape and amplitude of the signal determine, work analog, the circuit for long-term stabilization must periodically adjusted.

The above problems in the lock industry indicate that there is a need on an electronic lock system, the lock part of which is simply constructed and does not require a built-in energy source. The lock part should also be relatively damaging - or be clog-proof and a very large number of combinations of predetermined signals for lock actuation allow. The circuit of the lock part should ultimately also over a longer period of time can work stably across the board. The key part of such a facility could be the Power source to operate the lock included and should open the lock can without it having to be stirred into an opening in the lock.

The object of the invention is to provide such a lock system.

This object is achieved by the features specified in claim 1.

According to the invention, the key part of an inductively coupled, binary lock system with the help of a frequency-modulated carrier signal a series binary signals to the lock part. The lock part opens upon receipt of a predetermined one Sequence of binary signals the lock bolt.

The key part contains a storage register that is changeable Multi-bit key code stores. This key code is operated with the help of a voltage controlled Oscillator into a binary, frequency-shifted according to the key clock Carrier converted. After reinforcement, the key transfers the carrier via magnetic induction on the lock.

The lock part has a receiving coil and one on the frequency shifts of the key code responding receiver that receives the frequency-modulated carrier converts it back into binary pulses of multi-bit data. This is the key code containing binary data are in a storage register saved, from where they are fed to a comparator and from this with a predetermined one Reference code from a reprogrammable memory register can be compared. As soon as the compared codes match, it becomes the lock Opening lock rotor switched on.

Such a lock system also works without an opening; the castle thus cannot be made unusable by clogging the opening. In a preferred embodiment, the actual lock does not contain an internal energy source, with which there are no problems when the lock is far from an energy source away. The lock is relatively simple; so many can Locks can be made to operate by a single key.

In the following, the invention will be explained in more detail with reference to drawings Fig. 1 is a cross-sectional view of a key and a Lock when operating the locking mechanism; Fig. 2 is a circuit diagram of a component of the key, and FIG. 3 is a schematic diagram of the electronic circuit of the castle.

Identical symbols denote in the individual figures of the drawing corresponding components.

The electronic lock system according to the invention shown in FIG. 1 is indicated generally by 10. Your key part is 12 in operation the lock part 14 is shown.

The key part 12 shown in Fig. 1 has a power supply device 16, a generator 18 and a key induction device 20. The power supply facility 16 preferably includes a dry cell battery or other suitable DC power source on. A switch 40 of the key part is used to open or close the lock 12 used.

The lock part designated by 14 is in an outer housing 24, 25 housed. The housing 24, 25 contains a lock induction device 22, a Signal recognition stage 9, a motor 26, a gear 28 and a lock bolt 30. The motor 26, the gearbox 28 and the lock bolt 30 are suitable by means of one molded bracket 27 or other connecting element attached to the housing 2, 25. The motor 26 rotates the transmission when a voltage of suitable polarity is applied 28. The gear 28 engages the lock bolt 30 and pulls it out of a locked one Position in an unlocked position.

Fig. 2 shows a circuit diagram of the generator 18 and the key induction device 20 of the key part 12. The power required for the operation of the generator 18 is supplied from the power supply device 16. The generator 18 has a first memory 1, a read-only encoder 2, a voltage-controllable oscillator 3, a first amplifier 39 and a first logic stage 4.

In a preferred embodiment, a is made from multiple bit data existing locking code with the help of the fixed value encoder 2 in parallel in the first Memory 1 loaded. The read-only encoder 2 can either be a small plug-in circuit or be designed as an adjustable and easily reprogrammable switch. The one fed from the power supply device 16 first memory 1 can store a predetermined number of data bits of the lock code. The first store 1 is preferably designed as a shift register that is a parallel / serial converter is used for the multi-bit data. If the multi-bit data is already in serial Form can be supplied from the fixed-value encoder 2, the converter property is unnecessary of the first memory 1.

The serial output signal of the first memory 1 forms the input signal of the voltage controlled oscillator 3, with which the first memory 1 the frequency of the oscillator 3 changes from fl to f2, depending on whether the serially encoded output signal of the memory corresponds to number 1 or number 2. The output signal of the Oscillator 3 is a binary frequency modulated carrier that the first amplifier 39 is fed. The output of the first amplifier 39 is electrical to the Sehltissel induction device 20 connected.

For timing the operation of the key part 12 is the first logic level 4 provided. This has a first clock generator 5, which Outputs pulses of a fixed frequency, a binary counter 6, a first flip-flop (bistable multivibrator) 7 and the switch 40. The code transfer begins, when switch 40 is depressed. The switch 40 sets the first flip-flop 7 in its conducting state. As a result, both the clock generator 5 and the Oscillator 3 activated.

The output of the first clock generator 5 is electrically connected to the first Memory 1 and connected to the binary counter 6, so that both stages clock pulses take up. The clock pulses shift the data from the first memory 1 while the binary counter 6 counts the pulse with each clock pulse supplied to the memory 1. After the serial code of the memory 1 has been completely given up and after all of them have been pushed out Bits were counted, the binary counter 6 sets the first flip-flop 7 in the non-conductive State back, while the first flip-flop 7 in turn controls the binary counter 6 resets to zero.

After a voltage has been applied, the power supply device 16 operates the oscillator 3 at its normal, located in the middle between f1 and r2 Frequency fQ. When you press switch 4, the lock code is shifted in frequency the one driving the first amplifier 39 and the key induction device 20 Oscillator 3 converted. After the locking code has been converted completely, it works the oscillator 3 continues on the frequency t until the power supply device 16 is switched off.

Since the power continues to the normally passive switching of the Key part 12 is supplied, there remains enough time for the motor 26, for example a few seconds to open the lock by means of the lock bolt 30.

The .nchloßinduktionseinrichtung 22 takes the by magnetic induction from the key induction device 20 transmitted signals. Unless the coupling between the key part 12 and the lock part 14 through sheet metal occurs, the metal should preferably be non-magnetic and to reduce it eddy current losses have a relatively low electrical conductivity. Under These conditions can be the center frequency f0 in the order of 50 to 5000 Hz.

If the electromagnetic energy between key part 12 and Lock part 14 is transferred via non-metallic, plastic-like material, the center frequency rO can also be increased considerably beyond 5000 Hz, since that Penetration of the electromagnetic energy neither by the permeability nor by the essentially negligible electrical conductivity of the plastic-like Material is limited.

Fig. 3 shows a circuit diagram of the signal detection stage 9, the motor 26 as well as the lock induction device provided with a center tap 22nd of the lock part 12. The signal recognition stage 9 has a capacitor 15, first and second diodes 11 and 13, respectively, a frequency key shifting receiver 21, a second memory 23, a second logic stage 19, a power memory 38 and a motor controller 37.

The AC output of the center-tapped Castle induction device 22 is fed to the first and second diodes 11 and 13, respectively. the power memory 38 and the signal recognition stage 9 with direct current power supply.

The AC output of the lock induction device 22 is also fed to the receiver 21 scanning the frequency shifts.

The power store 38 is connected to the input of the engine controller 37 connected. The motor controller 37 may have a bridge driver so that the polarity on motor 26 can be reversed in response to a signal. When the engine had previously walked in a direction that would lock the lock, it will run after reversing polarity in the opposite direction, opening the lock. In another embodiment the motor control 37 can be formed by a simple switch, which according to The supply of a signal closes the circuit of the motor 26.

After receiving a signal switching on the motor 26, the power supplied to the motor 26 with a polarity for which it is in the direction of the opening of the lock turns.

On the one hand, the capacitor 15 ensures sufficient resonance of the Lock induction device 22 and on the other hand smooths the transmitted signals. The lock induction device 22, which is provided with a center tap, is by means of of the capacitor 15 to the transmitted from the key induction device 20 frequency f0 matched. The quality factor (Q) of the resonance circuit, i.e. the steepness of the resonance curve, is chosen so that the frequencies fl and f2 of the transmitted signal in the upper Are part of the flanks of the resonance curve. The frequency f0 is chosen so that the Bandwidth requirements when transmitting a 16-bit data stream of the frequency shift key code are met and the depth of penetration for a transmission of the signal over at least 1.5 to 3.2 mm of non-magnetic stainless steel or other, essentially non-magnetic materials with low electrical conductivity, e.g. Plastic with fillings etc.

sufficient.

The receiver 21 converts this from a binary frequency-modulated carrier wave existing output signal of the lock induction device 22 in electrical pulses for binary bits of the lock code data. This multi-bit data is the input of the second memory 23, which is preferably designed as a shift register and serves as a series / parallel converter for this data. The second memory 23 However, it can also be designed as a read-only memory with a predetermined number Stores data bits and can deliver them serially.

The output of the second memory 23 is coupled to a comparator 34, which in addition from a programmable lock code encoder 29 a reference code records.

The comparator 34 compares the multi-bit data determining the key code with the reference code. The memory 23 outputs the multi-bit data preferably in parallel so that only a comparison of the entire locking code with the reference code takes place per unit of time. If the second memory 23 outputs the data serially, so the locking code can be compared bit by bit with the reference code.

The second Loglkstufe 19 controls the timing of the operation Lock part 14. It has a second clock generator 31, a second binary counter 33 and a second flip-flop 36.

The second clock generator 31 is on the input side to the receiver 21 connected and takes from this a Synohronisierimpuis on. The outcome of the second Taictgenerator 31 is connected to the second memory 23 and supplies Clock pulses to this.

After synchronization with the series output of the receiver 21 delivers the second clock generator 31 clock pulses through which the incoming serial data bits in the second memory 23 are classified and read. The second binary counter 33 is connected on the input side to the second clock generator 31 and counts the supplied clock pulses. The output of the second binary counter 33 is to the comparator 34 connected and activates this for a single comparison if the memory 23 has received the entire lock code. If the comparison shows that the lock code and the reference code coincide in all bits the comparator 34 has an output signal that the second flip-flop 36 in the conductive State sets.

If the comparison shows that the locking code and the reference code are not matches in all bits, the second flip-flop 36 is not set and the second binary counter 33 switches the second clock generator 31 ineffective, whereby other locking codes can no longer be loaded into the second memory 23.

The motor controller 37 has a bridge driver that controls the polarity of the electrical signal applied to the motor 26 reverses when the second flip-flop 36 was placed in its conductive state. The motor 26, which was previously in a the lock has turned in the locked direction, now turns in the opposite direction Direction and open the lock. The flip-flop 36 is in its conductive state in addition one Output signal to the input of the second binary counter 33, which resets it to zero.

L e r s e i t e

Claims (6)

Claims 1. Electronic lock system, g e k e n n -e e i c h n e t by a key part (12) with a multitude of binary, frequency-modulated Carrier signals generating generator (18) and one electrically to the generator (18) connected first induction device (20) and by a lock part (14) with a second induction device (22) which is arranged to be in a predetermined spatial position to the key part (12) with the first induction device (20) of the key part (12) can be inductively coupled to a signal recognition stage (9), which responds to the signals of the generator (18) of the key part (12) and a predetermined one Sequence of binary signals with the sequence in the carrier signal of the generator (18) contained binary signals compares with one to the signal recognition stage connected and operated by this motor depending on the comparison (26) and with a movable lock bolt coupled to the motor, the vo Motor movable between a locked position and an unlocked position when energized is. 2. Lock system according to claim 1, characterized in that g e -lc e n n z e i c h n e t that the generator (18) has a first memory (l), which is an electrically changeable Multi-bit lock code stores, as well as one to the output of the first memory (1) connected oscillator (3), which has the binary, the key code containing electrical pulses into a binary frequency-modulated signal and outputs that at the output of the oscillator (3) a first amplifier (39) on the input side is connected, the output signal of which is the input signal of the first induction device (20) and that a first logic stage (4) having two outputs with its one output to the first memory (1) and with its second output to the oscillator (3) is coupled and the transmission of the binary data to the oscillator (3) is timed controls and effectively switches the oscillator (3). 3. Lock system according to claim 2, characterized in that g e -k e n n z e i c h n e t that the first logic mute (4) has the following features: one on the output side to the first memory (1) connected, first clock generator (5), the one the Data bits of the key code in the oscillator (3) inserting clock signal outputs the first memory (1), one connected to the output of the clock generator (5), first counter (6) that counts the clock pulses and a flip-flop (7) with start switch (40), which is connected with its input to the first counter (6) and three Output signals indicating the first of which is the first Counter (6), the second can be fed to the clock generator (5) and the third to the oscillator (3), such that the oscillator (3) and the clock generator (5) by means of the switch (40) set flip-flop (7) are activated and the first counter (6) the Resets the flip-flop (7) after all the data bits of the first memory (1) have been output and the flip-flop (7) in turn resets the first counter (6) to zero. 4. Lock system according to claim 2, characterized in that g e -k e n n z e l c h n e t that the signal recognition stage (9) has the following features: one to the second induction device (22) connected capacitor stage (15) for increasing the resonance and smoothing of transmitted signals, first and second, respectively, to the second Induction device (22) connected diode stages (11, 13) to supply the Lock part (l4) with direct current power, one to the output of the second induction device connected receiver (21), the carrier signal containing the lock code picks up and converts it into a binary, electrical pulse signal, one on the input side connected to the output of the receiver (21), the second memory (23), the Receives and stores locking code, a programmable code memory (29), the contains a reference lock code, a comparator (34) which reads the lock code of the second memory (23) and the reference locking code of the programmable code memory (29) picks up and emits an output signal when the codes match, a energy storage device connected to the output of the first and second diode stages (11, 13) (38), which stores a sufficient amount of energy to operate the motor (26), a motor controller (37) connected on the input side to the energy store (38), at the output of which the motor (26) is connected and the motor (26) when recording of a trigger signal, one with its input to the receiver (21) connected, second logic stage (19), which emits three output signals, of which the first to the second memory (23), the second to the comparator (34) and the third the engine control (37) can be supplied in such a way that the second logic stage (19) the chronological order of the multi-bit data in the second memory (23) controls and effectively switches the comparator (34) and to the signal of the comparator (34) sends the trigger signal to the engine control. 5. Lock system according to claim 4, characterized in that g e -k e n n z e i c h n e t that the second logic stage (19) has the following features: one on the input side connected to the receiver (21) and receiving a synchronization pulse from it second clock generator (31), the one the multiple bit Isten of the second memory (23) outputs the controlling clock pulse signal to the second memory (23), one on the input side to the clock generator (31) connected, second counter (33), which the clock pulses picks up and counts and the output is connected to the comparator (34) and this effectively switches and one connected on the input side to the comparator (34) Flip-flop (36) with two outputs, one of which to the motor controller (37) and the other is connected to the second counter (33) so that the match the code indicating signal of the comparator (34) sets the flip-flop so that it the trigger signal to the motor control (37) as well as a second counter (33) emits a trigger signal resetting to zero to the second counter. 6. Lock system according to claim 5, characterized in that g e -k e n n z e i c h n e t that the second counter (33) has an output at the input of the second clock generator (31) is connected and deactivates it if the locking code and the Reference locking codes do not match.