SU798940A1 - Fire alarm - Google Patents

Description

(54) DEVICE FOR SECURITY-FIRE ALARM

The device contains a unit for reproducing information reproduction, the inputs of which are connected respectively to the receiving and control unit, the recording unit and the audible signaling unit, and its output is connected to the distribution unit connected to the inputs of the recording unit through the command generation and synchronization unit, and a voltage switching unit is inserted into the switching and broadcasting device, the input of which is connected to the receiving-transmitting unit and the unit through the selection unit distribution, and the output through the linear blocks and two-wire communication line connected to the terminal blocks C2.

The disadvantage of the device is the relatively low noise immunity and, as a result, the low reliability of the device.

The purpose of the invention is to increase the reliability of the device.

The goal is achieved by introducing a rectangular impulse generator (p-1) of the delay blocks, a switch and a decoupling unit, the output of the rectangular impulse generator connected to the transmitter input, and the starting start of the rectangular impulse generator connected to the device. one output of the switch, the other output of which is connected to the input of the stop of the square-wave generator, the input of the switch is connected to the outputs of the detectors, the input of one of which is connected to the starting output of the transmitter directly, and the inputs of the other detectors are connected to the starting output of the transmitter via the appropriate delay unit, output the isolating unit is connected to the input of the switch, and the input of the isolating unit is connected to the starting output of the transmitter.

FIG. 1 shows a block diagram of the device; in fig. 2 and 3 - the sequence of pulses and radio pulses.

The device contains a control panel 1, filters 2, transmitter 3, rectangular impulse generators 4, Comm FU 5, from broadcasters b, delay blocks 7, switches 8, alarm sensors 9, power bus 10, decoupling unit 11.

The device works as follows.

In each polling cycle, tracing unit 3 generates a marker radio pulse, which serves to indicate the origin, which is fed to the receiving and control panel 1. In addition, the transmitter unit 3 with a known delay t generates

quite a powerful impulse that comes from the starting output. the inputs of the detectors included in the circuit are parallel to each other, and to the input of one of them directly, and to the inputs of the subsequent ones through the corresponding delay blocks 7, and to the input of the decoupling unit 11, which ensures the passage of signals in this direction.

All detectors b in the device are numbered according to the serial numbers of the protected objects, while the first number is assigned to the detector, whose input is directly connected to the start output of the broadcast device. Each detector b, triggered by the leading edge of an impulse from transmitter 3, generates a rather short signal and delays it relative to the start time of the same detector, which can take on discrete values At, 2 ГG, 3At ... mAtH sends it to the switch input 5 Each such value corresponds to a specific position of the code switch 8 and the state of the sensors 9 of the signaling system, and, consequently, to the type of the transmitted message. Here m is the total number of possible messages.

The delay units 7 connected to the detectors 6 provide delays whose durations in accordance with the sequence numbers of the detectors connected to them form a sequence: mut, 2п1ДС,. , X. . m (n - 1) dT, where n is the sequence number of the detector, and hence the protected object. Thus, if we assume that the condition –i. Is satisfied, where t is the length of the communication line to the most distant object from the translation device, with the speed of light, then in each polling cycle, the input of the adder 5 comes in pulses (the pulse from the output 11) in accordance with the sequence number of the object, and the time intervals between them depend on the type of messages transmitted from the objects.

Switch 5 (for example, a trigger with direct and inverse outputs and a general start) only works if the peak power received at its pulse input is greater than a certain threshold value, and it has two states: one state corresponds to that that the pulse from the input follows one output of switch 5, and the other to the fact that the pulse arrives at the other output of switch 5. In addition, when each switch 5 triggers, its state changes, as a result of which the previous signal goes to one output switch 5, and the next - on

| another. Therefore, at the Start and Stop inputs of the square-wave impulse generator 4, connected to the outputs of the switch 5, the pulses are received in alternation order.

The generator of 4 rectangular pulses, operating in the standby mode, generates common-angle pulses, the time of formation of the leading edge of which coincides with the moment of arrival of the pulse at the Start input, and the time of formation of the trailing edge with the moment of arrival of the pulse at the input Stop. Thus, the duration of such a pulse is determined by the time interval between the moments of arrival of signals at the Start and Stop inputs, respectively, if after a certain time after the arrival of the pulse at the Start input, the Stop pulse does not follow the input, then the generator of rectangular pulses will form the back front is automatically in this case, the pulse duration will be determined before the specified time interval d9. As a result, a sequence of square impulses and pauses, the time position number of which corresponds to the number of the object being monitored, arrives at the transmitter input.

The transmitter 3, whose power buses 10 power the detectors 6 and their corresponding code switches 8 and signaling sensors 9, converts the video pulses arriving at its input into radio pulses and, through the filters 2, directs them to the input of the remote control 1.

As a number (dl) in FIG. 2 and FIG. 3 shows the sequence of pulses and radio pulses, arriving respectively at the input of the transmitter 3 and the control panel 1 in one polling cycle, moreover, FIG. 2a and fig. They correspond to the case of an even number of objects and to the initial state of the switch 5, when the pulse from the output of decoupling unit 11 follows the input of the Start of the generator 4 to the right angular pulses; FIG. 2b and fig. 36 correspond to an odd number of objects; FIG. 2b and FIG. They correspond to the case of an even number of objects and the initial state of the switch 5, when a pulse from the output of decoupling unit 11 follows the input of the Stop generator of rectangular pulses; FIG. 2d and fig. Zg is the same state, but the number of objects is odd.

In all cases, at the end of a flax sequence there should be an impulse or. pause with a duration of dv, significant but longer than all others. These

pulse or pause is used to mark the end of a polling cycle. After the transmitter 3 receives such a pulse or pause, the polling cycle repeats,

The control panel 1 receives radio pulses and calculates the time intervals T, T, ... T according to the following rule:

-tTg if uT -Toijto

0 if dt,

lT, .- mуT

,

five

where dT is the duration of the first

I pause (Fig. 3); l T - the duration of the first pulse;

0 lT ,, dT ..., dTu, is the duration of subsequent impulses and pauses.

In addition, each value of T, T, j ..., T, when all detectors 6 are functioning, coincides with the allowable

5 accuracy with one of m possible values of d, 2л1; ..., tdG corresponding to certain messages. The control panel 1 converts these values into the corresponding signal commands and issues them to the dispatcher.

If, on the other hand, the K detectors go out of line in the device, starting with i-ro, then the time interval T, calculated using the above algorithm, is within:

KttidT T..4 (K h - t)

and the control panel 1 gives the dispatcher the appropriate signal

0 command about the failure of these K detectors, and the time interval T-, corresponding to the first operating detector after a series of additional detectors that failed,

5 determines from the relation:

T.LT. (C) tdG

The control panel 1 converts these values into the corresponding signal commands and assigns them to the controller. ,

The invention makes it possible to increase the reliability of the operation of the entire device, since the failure

5 Any detector does not lead to any other being overrun. In addition, in the proposed device, the peak power of the pulses of the detectors is possible compared with the known device with the same required energy due to the reduction of the duration of these pulses up to a level where the effective width of the spectrum will be approximately equal to the transmission bandwidth. tract

transfer. In the known device, the use of such short pulses is impossible due to the broadening of these pulses caused by the transmission path by a value of the order of the pulse duration, which leads to a distortion of the transmitted information. In the proposed device, such information distortion does not occur, since it is incorporated in the time intervals between pulses, and the duration of these intervals can be much longer than the duration of the pulses themselves.

In turn, an increase in peak power will allow an increase in the threshold of a device, in particular, a switch accepting these pulses, which will increase the noise immunity and, accordingly, the system reliability.

Claims (2)

1. Authors certificate of the USSR 435550, cl. G 08 B 25/02, 1973. 2. Authors certificate of the USSR 386416, cl. G 08 B 25/02, 1970 (prototype).  I At H-r |: .j h  M I AS f - - 4 V - 4 98940 V.,. V (tv YH, i - 1 h   I I 1 & e j #) corner 5