SU720446A1 - Code lock - Google Patents

Description

The invention relates to a burglar alarm technique and can be used to remotely disable the burglar alarm of locked objects.

Code locks are known, for example, for disabling security alarms, made on the relay-contact elements 1.

The closest technical solution to the proposed device is a code lock containing a decoder, the output of which is connected to the first input of the voltage analyzer unit, the first output of which is connected through the violation fixation unit to the first input of the switching unit, the second output of the voltage analyzer switching, the output of the coding unit is connected to the third input of the switching unit, the output of the switching unit is connected to the second input of the voltage analyzer 2.

However, these devices have drawbacks, the main ones of which are: the presence of several connecting lines from the decoder to the encoder; the ability to select a code by simulating a reference voltage at the input of a voltage analyzer unit; The bounce of the contacts of the descrambler buttons when dialing a code can cause false positives of the counting circuit of the switching unit, which reduces its reliability.

The aim of the invention is to improve the reliability of the code lock by

0 reducing the number of connecting lines from the decoder to the encoder, eliminating the possibility of selecting a code and simplifying the decoder cxeivnj. This is achieved by introducing a trigger into the code block, the input of which is connected to the output of the decoder, one output of the starting block is connected to the fourth input of the switching unit, the other output - to the third input of the voltage analyzer, and the input to the output of the decoder.

The invention is illustrated in the drawing, which is a functional diagram of a code lock.

five

The lock contains a startup unit 1, a decoder 2, a voltage analyzer 3, a switching unit 4, a coding unit 5, a violation fixing unit 6. pulse shaping unit 7

LINE, executive node 8, code buttons 9-18, switches 19-21, triggers 22, 23, logic elements 24-27, exemplary resistors 28-29, trigger resistor 30, power supply 31, resistor 32.

The device works as follows.

The full cycle of the code lock consists of four cycles. All four measures correspond to the correct 1-1 set of code. During the first three cycles, the code is dialed, on the fourth cycle, the triggers 22, 23 are reset to the initial state and are prepared to receive the next control pulse of the first cycle,

When Hs1compression one of the code buttons 9-18 decoder 2 corresponding to the first digit of the code, through the closed contacts of this button in one of the shoulders of the bridge, the two arms of which are formed exemplary resistors 28 and 29, the third shoulder of the bridge is formed in series by one of the decoder 2 resistors and the resistor 30, and the fourth one of the resistors of the coding unit 5, the voltage analyzer 3, turns on the resistor of the decoder 2. Simultaneously, through the closed contacts of this button, the starting pulse formation circuit of the unit 1 closes uska The trigger unit 1 contains a key and a standby multivibrator, controlled by a trigger pulse. The minimum duration of the generated pulse is determined by the parameters of the standby multivibrator, and the maximum duration, by the time the descrambler button is pressed.

Generated switching impulse Connects the supply voltage to the control pulse shaping unit 7 of the voltage analyzer 3 and to the logic elements 24-27 of the switching unit 4.

When dialing the first digit of the code, the status of the triggers 22, 23 corresponds to the case when the logic element 24 is open and the logic elements 25-27 are closed.

Through the open logic element 24 and the closed contacts of the switch 19, the resistor of the coding unit 5 is inserted into the shoulder of the analyzer bridge

3 voltage opposite to the turn-on shoulder of the decoder 2.

With this, a control pulse appears at one of the outputs of this block. The formation of the trailing edge of the control pulse occurs at the moment when the decoder button is released. The control pulse is fed to the input of the switching unit 4 and the falling edge switches it, preparing the block

4 commutation for dialing the second digit of the code.

At the moment of pressing the next code button of the decoder 2, corresponding to the second digit of the code, the code combination of the first cycle is recorded at the outputs of the flip-flops 22, 23. With this code combination, one of the resistors of the coding block is connected to the bridge circuit via the closed contacts of the switch 20 and the open logic element 24. The process of forming the second control pulse is similar to the case of correct dialing of the first code digit. The second control pulse prepares the switching unit for dialing the third digit of the code. In this case, the “outputs of the triggers 22, 23 of the counting circuit are recorded with the code combination of the second cycle.

When the third last digit of the code is dialed, the resistor of the coding block 5 is connected to the bridge circuit via the open logic element 26 and the closed contacts of the switch 21.

The third control pulse records, at the outputs of the flip-flops 22, 23, a code combination corresponding to the third cycle. In this cycle, the logic element 27 is opened and the logic elements 24-26 are closed. After dialing all three digits of the code through the open logic element 27, the executive node 8 is activated, blocking the alarm sensors. At the same time, a resistor 32 is connected to the shoulder of the bridge circuit of the voltage analyzer unit along this circuit. This resistor performs the function of one of the ten resistors of the coding unit at the moment of dialing the fourth digit, since in this case the code combination of the third tact when the logic elements 24-26 are closed and none of the ten resistors of the coding block can be connected to the bridge circuit.

The magnitude of the resistor 32 is selected in such a way that when one of the decoder buttons that perform the RESET function is pressed, the balance of the voltage analyzer unit is balanced. Therefore, in addition to dialing the code, this button is used as the RESET button.

With the arrival of the next fourth counting control pulse in the trigger trigger circuit 22, the switching unit 4 again returns to the initial state corresponding to the first cycle.

If the code is incorrectly typed or if there is any violation of the code dialing sequence on the decoder 2, the device records the deviation. In this mode, at the output of the voltage analyzer 3, an alarm appears that goes to the violation fixing unit 6. Using the invention will provide silent input.

to the protected object and thus significantly reduce the issuance of false alarms to the control panels and, consequently, the number of departures of task forces to the protected objects.

The proposed combination lock will be used to protect financial institutions or households.

Claims (2)

1. USSR author's certificate No. 222904, cl. G 08 B 29 / 00.05.04.64. 2. USSR author's certificate P511614, cl. G 08 B 21/01, 11.11.74 (prototype).