RU2641886C1 - Autonomous signal-start firefighting system - Google Patents

Abstract

FIELD: fire safety.

SUBSTANCE: autonomous signal-start firefighting system contains a series-connected thermal starter 1, a current source 2 with a pyrotechnic activator 3, a time relay 4, a signal device 5, an actuator 6, a housing 7, a rod 8, a compression spring 9, an end portion 10 of a springed rod 8, a heat sensitive clamp 11, a solenoid 12, a central axial channel 13, terminals 14, an incandescent bridge 15, a weighed portion of initiating substance 16, an end portion 17 of a springed rod 8, an edge spear 18, a capsule 19, a sealed casing 20, solid stick 21, electrical outputs 22. The transmitter comprises a master oscillator 23, n is a drop-out delay line 24.i (i = 1, 2, …, n), a phase-inverter 25.j (j = 1, 2, …, m), an adder 26, a power amplifier 27, and a transmitting antenna 28. The receiver includes a receiving antenna 29, a high frequency amplifier 30, mixers 31 and 47, a sawtooth voltage generator 32, heterodynes 33 and 46, intermediate frequency amplifiers 34 and 48, a FM signal detector 35, spectrum analyzers 36 and 38, phase doubler 37, comparison block 39, threshold blocks 40 and 50, delay lines 41 and 44, switches 42 and 51, a phase detector 43, a registration block 45, a correlator 49, a narrowband filter 52, phase-inverter circuits 53, 56 and 59, adders 54, 57 and 60, bandpass filters 55 and 58.

EFFECT: increase selectivity and noise immunity of the receiver by suppressing false signals received through the forward channel and intermodulation channels.

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Description

The proposed system relates to fire fighting equipment, and more particularly to automatic fire alarm systems and controlling fire fighting equipment, and can be used for fire protection of various objects and simultaneous transmission of alarms to a remote control point.

Autonomous signal-starting fire extinguishing systems are known (ed. Certificate of the USSR No. 1261676, 1277159; RF patents No. 2022250, 2024064, 2115451, 2138856, 2170951, 2175779, 2234735, 2242921, 2254614, 2275688, 2344859, 2355037, 243429, 293429 US No. 3786461, 4661320; UK patent No. 2323398; EP patents No. 0360126, 0657728 and others)

Of the known systems closest to the proposed is the "Autonomous signal-starting fire extinguishing system" (RF patent No. 2.520.429, G08В 17/00, 2013), which is selected as a prototype.

The known system provides the suppression of false signals (interference) received on the mirror and Raman channels due to the correlation processing of channel voltages. The remarkable property of the correlation function of complex signals with phase shift keying is used.

However, in addition to the mirror and Raman channels, there are other additional receiving channels, such as intermodulation channels and direct channels.

The presence of false signals (interference) received through the direct channel and intermodulation channels leads to a decrease in the selectivity and noise immunity of the receiver.

An object of the invention is to increase the selectivity and noise immunity of the receiver by suppressing spurious signals (interference) received through the direct channel and intermodulation channels.

The problem is solved in that an autonomous signal-starting fire extinguishing system, containing, in accordance with the closest analogue, a heat starter connected in series, a current source with a pyrotechnic activator and a time relay, which is connected to the signal device through a normally closed contact and is additionally connected to the actuator through a normally open contact, while the thermal starter and current source with the pyrotechnic activator are structurally combined and enclosed in a building ce, the thermal starter is made in the form of a spring-loaded rod installed with the possibility of translational movement and interaction with the pyrotechnic activator of the current source, moreover, one of the end sections of the spring-loaded rod is arranged to protrude from the housing and is equipped with a latch made of material with a thermomechanical shape memory, the current source includes a shell placed in it with the possibility of contact with a pyrotechnic activator solid-state block of solid-salt non-separatic electro a chemical composition based on lithium alloy and iron disulfide, the signal device is made in the form of a signal transmitter to a remote receiver, while the signal transmitter is made in the form of a serially connected master oscillator, n is a tap delay line, phase inverters included in m are taps of an n - tap line delay, adder, the (n + 1) -th input of which is connected to the output of the master oscillator, power amplifier and transmitting antenna, and the receiver is made in the form of a series-connected receiving antenna and high-frequency amplifier frequency, successively connected sawtooth generator, first local oscillator, first mixer, first intermediate frequency amplifier, correlator, second threshold block, second key, the second input of which is connected to the output of the first intermediate frequency amplifier, phase doubler, second spectrum analyzer, comparison unit, the second input of which is connected through the first spectrum analyzer to the output of the second key, the first threshold block, the second input of which is connected to its output through the first delay line, the first key, the second input of which is connected to the output of the second key, a phase detector, the second input of which is connected through the second delay line to the output of the first key, and the registration unit, the second local oscillator, the second mixer and the second intermediate frequency amplifier are connected in series to the output of the sawtooth voltage generator, an output connected to the second input of the correlator, the control input of the sawtooth generator is connected to the output of the first threshold block frequency ω _{r1, r2} ω first and second geterodi s are separated by twice the value of the intermediate frequency

selected symmetrical with respect to the carrier frequency ω _{from the} received signal

and are tuned synchronously, differs from the closest analogue in that it is equipped with a narrow-band filter, two band-pass filters, three phase inverters and three adders, and a narrow-band filter is connected to the output of the high-frequency amplifier, the first phase inverter, the first adder, the second input of which is connected to the output of the amplifier high-pass, first bandpass filter, second phase inverter, second adder, the second input of which is connected to the output of the first adder, second bandpass filter, third phase invert and a third adder, a second input coupled to an output of the second adder and an output coupled to a second input of the first and second mixers.

The structural diagram of an autonomous fire alarm system is shown in FIG. 1. A graph of the voltage across the output contacts of the current source is shown in FIG. 2. A power source with a pyrotechnic activator and a thermal actuator of electrical action, structurally combined in a single housing, are shown in FIG. 3. A power source with a pyrotechnic activator and thermal shock actuator, structurally combined in a single housing, is shown in FIG. 4. The block diagram of the transmitter is shown in FIG. 5. The block diagram of the receiver is shown in FIG. 6. Frequency diagrams illustrating the formation of additional receive channels are shown in FIG. 7, 8 and 9.

The autonomous fire alarm system includes a heat starter 1 connected in series, a current source 2 with a pyrotechnic activator 3, and a time relay 4, which is connected to the signal device 5 via a normally closed contact and is additionally connected to the actuator 6 through a normally open contact.

The thermal starter 1 and the current source 2 with the pyrotechnic activator 3 are structurally combined and enclosed in a single housing 7 made of an insulating material. As an insulating (non-conductive) and non-magnetic material in the manufacture of system elements, plastic materials, materials based on glass or organ fiber can be used. The thermal starter 1 is made in the form of a cylindrical rod 8 installed in the housing 7. The rod 8 is equipped with a translational displacement drive, which is a compression spring 9 mounted coaxially on the rod 8 in its middle part. The end portion 10 of the spring-loaded stem 8 is arranged to protrude from the housing 7 and has a figured groove for interaction with a heat-sensitive latch 11, made in the form of a bracket with a diameter of about 20 mm from a material with thermomechanical shape memory, for example titanium nickelide.

The thermal starter 1 has the ability to interact with the pyrotechnic activator 3 of the current source 2 in two different ways, differing in their structural embodiments.

The thermal actuator 1 of electrical action depicted in FIG. 3, is equipped with a solenoid 12 with a central axial channel 13, the terminals 14 of which are electrically connected to the pyrotechnic activator 3. In this case, the pyrotechnic activator 3 is made in the form of an incandescent bridge 15, electrically connected to the terminals 14, and an initiating substance 16 weighed on it. In addition , the second end section 17 of the spring-loaded rod 8 is magnetized (in the drawings, the corresponding poles of the permanent magnet are denoted by the letters S and N) and installed with the possibility of movement inside the central axial channel 13 of the solenoid 1 2.

The thermal impact starter 1 shown in FIG. 4, characterized in that the second end portion 17 of its spring-loaded rod 8, facing the pyrotechnic activator 3, is equipped with a conical striker 18. In this case, the pyrotechnic activator 3 is made in the form of an igniter and a weight of the initiating substance 16 and the capsule 19. The current source 2 is a device constant-readiness power supply based on a thermal chemical current source of backup type, which is a design in an airtight shell 20 by a solid-state checker from solid-salt non-detachable electrochemistry composition based on lithium alloy and iron disulfide. In this case, the solid-state checkers 21 are in direct contact with the weighed portion of the initiating substance 16 of the pyrotechnic activator 3, which is also mainly located in the hermetic shell 20. The current source 2 has electrical leads 22, which are normally connected to the input contacts of the time relay 4.

The time switch 4 is an electronic on / off time switch, which is electrically connected through a normally closed output contact to a signal device 5 and simultaneously electrically connected to an actuation device 6 through an normally open output contact 6. Actuator 6 is primarily a fire extinguishing aerosol generator with electrical means start, for example a squib, which is actually connected to the normally open contact of the timer 4 The signal device 5 is preferably a radio signal transmitter to a remote receiver.

The transmitter contains serially connected master oscillator 23, m is a delay delay line 24.i (i = 1, 2, ..., n), a phase inverter 25.j (j = 1, 2, ..., m) is included in m - taps n - branch delay line 24.i, the adder 26, the (n + 1) -th input of which is connected to the output of the master oscillator 23, the power amplifier 27 and the transmitting antenna 28.

The receiver includes a series-connected receiving antenna 29, a high-frequency amplifier 30, a narrow-band filter 52, a first phase inverter 53, a first adder 54, a second input of which is connected to the output of a high-frequency amplifier 30, a first band-pass filter 55, a second phase inverter 56, and a second adder 57, the second input of which is connected to the output of the first adder 54, the second bandpass filter 58, the third phase inverter 59, the third adder 60, the second input of which is connected to the output of the second adder 57, the first mixer 31, the second input of which is through the first the local oscillator 33 is connected to the output of the sawtooth voltage generator 32, the first intermediate frequency amplifier 34, the correlator 49, the second threshold block 50, the second key 51, the second input of which is connected to the output of the first intermediate frequency amplifier 34, a phase doubler 37, the second spectrum analyzer 38, block 39 comparison, the second input of which through the first spectrum analyzer 36 is connected to the output of the second key 51, the first threshold block 40, the second input of which through the first delay line 41 is connected to its output, the first key 42, the second input of which is connected ene yield the second switch 51, phase detector 43, the second input thereof via a second delay line 44 is connected to the output of the first key 42 and the register unit 45. A second oscillator 46, a second mixer 47, the second input of which is connected to the output of the third adder 60, and a second intermediate-frequency amplifier 48, the output of which is connected to the second input of the correlator 49, are serially connected to the output of the sawtooth voltage generator 32. The control input of the sawtooth voltage generator 32 is connected to the output of the first threshold block 40.

Spectrum analyzers 36 and 38, a phase doubler 37, a comparison unit 39, a first threshold block 46 and a first delay line 41 form a detector (selector) 35 of the phase-shift (PSK) signal.

Autonomous alarm trigger fire extinguishing system operates as follows.

The system is effective when used primarily on remote, inaccessible and rarely visited objects. The main elements of the system are delivered to the object in assembled form and in cocked position, are installed stationary in the place of the most likely occurrence of a fire. After installing the fire extinguishing system, all fuses are removed, including from the rod 8 (not shown in the drawing), and it is put into standby mode.

When a fire occurs and the temperature rises in the zone of location of the heat-sensitive latch 11 to the activation threshold (72 ° C), a martensitic transformation occurs in its material, accompanied by the restoration of the predefined shape of the staple, the latter unclenches, restoring its shape, and releases the end portion 16 of the rod 8. Rod 8 under the influence of the spring 9 of the actuator (its translational motion), a downward movement begins. Together with the rod 8, its second end section 17 also moves. Further, a pyrotechnic activator 3 with a thermal actuator 1 of electric action or a pyrotechnic activator 3 with a thermal actuator 1 of shock action can be implemented.

In the first case, the spring-loaded rod 8 interacts with the pyrotechnic activator 3 by means of a magnetized second end portion 17, which moves inside the central axial channel 13 of the solenoid 12 and generates a current pulse transmitted through the electrical leads 14 to the glow bridge 15 of the pyrotechnic activator 3. The required electric pulse is 0.5-1.0 A, and the duration is 1-10 ms.

In the second case, the spring-loaded rod 8 interacts with the pyrotechnic activator 3 by means of a conical hammer 18, which strikes the capsule 19.

In both cases, ignition of a sample of the initiating substance 16 occurs, which in a short time melts the solid-salt electrochemical composition of the solid-state checker and puts the current source 2 into the state of generating a current of a given value.

As the graph shows (Fig. 2), a short activation time (t ₆ ≤1 s) allows the use of current source 2 in tools and devices with a short time to bring into working condition. During the period of time t ₁ , the signaling device 5 is turned on and functioning. The duration of the time period t _{1 is} provided by a time relay 4, set during the installation of the fire extinguishing system and depends on the schedule and emergency plan for the guarded facility. During the specified period of time, a normally closed electrical contact of the output of the time relay 4 with the signaling device 5 is necessarily maintained, which ensures the transmission of the radio signal to the remote receiver.

For this, the master pulse 23 generates a radio pulse

U _c (t) = V _c × Cos (ω _c t + ϕ _s ), 0≤t≤τ _E ,

where V _c , ω _s , ϕ _s , τ _E is the amplitude, carrier frequency, initial phase, and duration of the radio pulse.

The generated radio pulse from the output of the master oscillator 23 is fed to the input of the multi-tap delay line 24.i (i = 1, 2, ..., n) and to the (n + 1) -th input of the adder 26. In the multi-tap delay line 24.i the delay time between the nearest adjacent taps is equal to the duration of the radio pulse τ _E (τ _si = τ _E , i = 1, 2 .... n). In some taps of the delay line, phase inverters 25.j are included (j = 1, 2, ..., m), which provide 180 ° phase rotation at their outputs (in accordance with the identification code M (t) of the fire safety object). At the output of adder 26, a complex signal with phase shift keying (QPSK) is generated in the form of the algebraic sum of radio pulses from all taps of the delay line 24.i (i = 1, 2, ..., n) and from the output of the master oscillator 23

U ₁ (t) = V _c × Cos [ω _c t + ϕ _k (t) + ϕ _s ], 0≤t≤T _c ,

where ϕ _k (t) = {0, π} is the manipulated component of the phase, which displays the law of phase manipulation in accordance with the modulating code M (t), and ϕ _k (t) = const for kτ _e <t <(k + 1) τ _e and can change abruptly at t = kτ _e , that is, at the boundaries between elementary premises (radio pulses) (k = 1, 2, ..., n);

τ _e , n is the duration and number of elementary packages (radio pulses) of which the signal is composed of duration T _s (T _s = τ _e ⋅n).

This signal, after amplification in the power amplifier 27, enters the transmitting antenna 28, is radiated by it, is captured by the receiving antenna 29 installed at the control point, and through the high-frequency amplifier 30 and the adders 54, 57, 60, which have only one arm, arrives at the first inputs of the first 31 and second 47 mixers, the second inputs of which are supplied with the voltage of the first 33 and second 46 local oscillators of linearly varying frequency, respectively:

U _g1 (t) = V _g1 × Cos (ω _g1 t + πγt ² + ϕ _g1 ),

U _r2 (t) = V _r2 × Cos (ω t + πγt _r2 ² + φ _r2) 0≤t≤T _n

where γ = Df / T _p - the rate of change of the frequencies of the local oscillators 33 and 46 in a given frequency range Df;

T _p - the period of perestroika.

The frequencies ω _g1 and ω _{g2 of the} local oscillators 33 and 46 are spaced apart by a double value of the intermediate frequency 2ω _pr (Fig. 7)

ω _g2 -ω _g1 = 2ω _pr

selected symmetrical with respect to the carrier frequency ω _{from the} received signal

ω _with -ω _g1 = ω _g2 -ω _c = ω _ol and rebuild synchronously.

This circumstance leads to a doubling of the number of additional receiving channels, but creates favorable conditions for their suppression due to the correlation processing of channel voltages.

It should be noted that the search for complex QPSK signals in a given frequency range Df is carried out using a sawtooth voltage generator 32, which linearly changes the frequencies ω _g1 and ω _{g2 of the} local oscillators 33 and 46.

At the output of the mixers 31 and 47, a voltage of combination frequencies is generated. Amplifiers 34 and 48 are allocated voltage intermediate frequency:

U _pr1 (t) = V _pr1 ⋅ × Cos [ω _pr t + ϕ _k (t) -πγt ² + ϕ _pr1 ],

_Np2 U (t) = V _np2 ⋅ × Cos [ω _ave t-φ _a (t) + πγt _np2 ² + φ], 0≤t≤T _c,

where V _pr1 = 1 / 2V _c ⋅ × V _g1 ;

V _ol2 = 1 / 2V _c ⋅ × V _g2 ;

ω _CR = ω _s -ω _g1 = ω _g2 -ω _s is the intermediate frequency;

ϕ _pr1 = ϕ _with -ϕ _g1 ; ϕ _ol = ϕ _g2 -ϕ _s ,

which are complex signals with combined phase shift keying and linear frequency modulation (FMN-LFM).

These voltages go to two inputs of the correlator 49, the output of which produces a voltage V proportional to the correlation function R (τ), which is compared with the threshold voltage V _pore1 in the threshold block 50. The threshold level V _{pore1 is} exceeded only at the maximum voltage V _{max of the} correlator 49 ( V _max > V _por1 ).

Since the channel voltages U _CR1 (t) and U _CR2 (t) are formed by the same useful QPSK signal received on the main channel at a frequency ω _s (Fig. 7), there is a strong correlation between these channel voltages. The output voltage of the correlator reaches a maximum value of V _max and exceeds the threshold level of V _por1 in the threshold block 56 (V _max > V _por1 ).

It should also be noted that the correlation function R (τ) of complex QPSK signals has a remarkable property: it has a pronounced main lobe and a relatively low level of side lobes.

When the threshold level V _por1 is exceeded, a constant voltage is generated in the threshold block 50, which is supplied to the control input of the key 51 and opens it. In the initial state, the key 51 is always closed. In this case, the voltage U _pr1 (t) from the output of the first intermediate frequency amplifier 34 through the public key 51 is fed to the input of the detector (selector) 35 QPSK signal, consisting of a phase doubler 37, spectrum analyzers 36 and 38, comparison unit 39, threshold block 40 and the first delay line 41.

A voltage is generated at the output of the phase doubler 37

U ₂ (t) = V ₂ × Cos (2ω _pr t-2πγt ² + 2ϕ _pr1 ), 0≤t≤T _c ,

where V ₂ = 1 / 2V _pr1 , in which phase manipulation is already absent.

The width of the spectrum Δf _{2 of the} second harmonic of the signal is determined by the duration of the signal Δf ₂ = 1 / T _s , while the width of the spectrum Δf _{c of the} input QPSK signal is determined by the duration τ _{e of} its elementary premises Δf ₂ = 1 / τ _e , i.e. the width of the spectrum of the second harmonic of the signal is n times smaller than the width of the spectrum of the input signal Δf _c / Δf ₂ = n.

Therefore, when the phase of the QPSK signal is doubled, its spectral width “folds” n times. This circumstance makes it possible to detect and select the QPSK signal even when its power at the receiver input is less than the power of noise and interference.

The width of the spectrum Δf _{c of the} input QPSK signal is measured by the spectrum analyzer 36, and the spectrum width Δf _{2 of the} second harmonic of the signal is measured using the spectrum analyzer 38. Voltages V ₁ and V ₂ proportional to Δf _c and Δf _2, respectively, from the outputs of the analyzers 36 and 38 of the spectrum are supplied to the two inputs of the comparison unit 39. Since V ₁ >> V ₂ , a positive voltage is generated at the output of the comparison unit 39, which exceeds the threshold level V _por2 in the threshold block 40. The threshold level V _por2 is selected so that it does not exceed random interference. When the threshold voltage V _pore2 is exceeded, a constant voltage is generated in the threshold block 40, which is supplied to the control input of the switch 42, opening it, to the input of the delay line 41 and to the control input of the sawtooth voltage generator 32, turning it off. The key 42 in the initial state is always closed.

When the frequency tuning of the local oscillators 33 and 46 ceases, the following voltages are allocated by the amplifiers 34 and 48 of the intermediate frequency

U _pr3 (t) = V _pr1 × Cos [2ω _pr t + ϕ _k (t) + ϕ _pr1 ],

_WP4 U (t) = V _np2 × Cos [ω _ave t-φ _a (t) + φ _np2], 0≤t≤T _c.

the output of the doubler 37 phase in this case, the harmonic voltage

U ₃ (t) = V ₂ × Cos (2ω _pr t + 2ϕ _pr1 ), 0≤t≤T _s .

The voltage U _CR3 (t) from the output of the first intermediate frequency amplifier 34 through the public keys 51 and 42 is supplied to the two inputs of the phase detector 43 directly and through the delay line 44, the delay time τ _{s of} which is chosen to be equal to the duration τ _{e of the} chips (τ _s = τ _e ). In this case, the reference voltage necessary for the synchronous detection of the received PSK signal for each subsequent transmission is the previous transmission. A low-frequency voltage is generated at the output of the phase detector 43

U _n (t) = V _n × Cos ϕ _k (t), 0≤t≤T _s ,

where V _n = 1 / 2V _pr1 ² ,

proportional to the modulating code M (t) with the exception of the first elementary premise.

The phase detector 43 and the delay line 44 form an autocorrelation FMN demodulator, which is free from the phenomenon of “reverse operation” inherent in the known FMN signal demodulators (A. A. Pistolkors, V. I. Sidorov, G. A. Travin, D .F. Kostos).

The low-frequency voltage U _n (t) is detected by the recording unit 45.

The carrier frequency ω _s and the modulating code M (t) are identification signs of the fire safety object where the fire occurred. Based on these signs, a control point decides on the place of the fire and measures to eliminate it.

The delay time τ _{1 of} the delay line 41 is selected so that it is possible to fix and analyze the low-frequency voltage U _n (t). A fifteen-second pulse (t ₁ ≤15 _s ) is sufficient for reliable alarm transmission. During a period of time t ₂ , the actuator 6 fire extinguishing aerosol generator is connected and started. This connection provides a time relay 4, by the command of which, at the end of the time period t ₁ , the normally open output contact of the time relay 4 is closed with an electric trigger, for example, a pyratapron extinguishing aerosol generator. After triggering the squib of the fire extinguishing aerosol generator, the latter operates autonomously and does not need power supply from current source 2. For a reliable start of the fire extinguishing aerosol generator of the actuator 6, a five-second pulse is sufficient (t ₂ = 2-5 s).

After the time τ _{1, the} voltage from the output of the threshold block 40 through the delay line 41 is supplied to the reset input of the threshold block 40 and resets its contents to zero. In this case, the key 42 is closed, and the sawtooth voltage generator 32 is turned on, i.e. they are transferred to their original state.

When the next QPSK signal is detected at a different carrier frequency and with a different modulating code, the receiver operates in a similar way.

These FMN signals have high noise immunity, energy and structural secrecy.

The operation of the receiver described above corresponds to the case of receiving useful PSK signals along the main channel at a frequency of ω _s (Fig. 7).

If a false signal (interference) is received on the first mirror channel at a frequency ω _s1

U _Z1 (t) = V _zl × Cos (ω t + φ _{P1 P1),} 0≤t≤T _s,

then at the output of the mixers 31 and 47 the following voltages are generated, respectively:

_Np5 U (t) = V _np5 × Cos (ω _ave t-πγt _np5 ² + φ)

_Pr6 U (t) = V _pr6 × Cos (3ω t + πγt _ave ² + φ _pr6) 0≤t≤T _P1,

where V _pr5 = 1 / 2V _s1 × V _g1 ; V _ol6 = 1 / 2V _s1 × V _g2 ;

ω _CR = ω _g1 -ω _Z1 - intermediate frequency;

3ω _pr = ω _z2 -ω _Z1 - three times the value of the intermediate frequency;

ϕ _ol5 = ϕ _g1 -ϕ _z1 ; _pr6 cp = φ -φ _{r2 P1.}

However, only the voltage U _pr5 (t) enters the passband of the first intermediate frequency amplifier 34 and to the first input of the correlator 49. The output voltage of the correlator 49 is zero, the key 51 does not open, and a false signal (interference) received via the first mirror channel at the frequency ω _s1 is suppressed.

If a false signal (interference) is received on the second mirror channel at a frequency ω _z2

U _s2 (t) = V _s2 × Cos (ω t + φ _{s2 s2)} 0≤t≤T _s2,

then at the output of the mixers 31 and 48, the following voltages are generated, respectively:

U _pr7 (t) = V _pr7 × Cos (3ω _pr t-πϕt ² + ϕ _pr7 ),

U _pr8 (t) = V _pr8 × Cos (ω _pr t + πγt ² + ϕ _pr8 ), 0≤t≤T _s2 ,

where V _pr7 = 1 / 2V _s2 × V _g1 ;

V _ol8 = 1 / 2V _s2 × V _g2 ;

3ω _pr = ω _z2 -ω _r1 - three times the value of the intermediate frequency;

_straight ω = ω _z2 -ω _s2 - intermediate frequency;

ϕ _ol7 = ϕ _z2 -ϕ _g1 ; ϕ _ol8 = ϕ _z2 -ϕ _g2 .

However, only the voltage U _pr8 (t) falls into the passband of the second intermediate-frequency amplifier 48 and to the second input of the correlator 49. The output voltage of the correlator 49 is also zero, the key 51 does not open and a false signal (interference) received via the second mirror channel at the frequency ω _z2 is suppressed.

For a similar reason, false signals (interference) received on the first Raman channel at a frequency ω _k1 , or on a second Raman channel at a frequency ω _g2 , or any other Raman channel are also suppressed.

If spurious signals (interference) are simultaneously received by the first ω _P1 and second ω _s2 mirror channels, the bandwidth of the amplifier 34 and 48 an intermediate frequency and to two inputs of the correlator 49 fall voltage U _np5 (t) and U _pr8 (t), respectively. But the key 51 in this case does not open. This is due to the fact that two false signal U _P1 (t) and U _s2 (t) takes on different frequencies ω _P1 and ω _P2, between the educated channel voltage U _np5 (t) and U _pr8 (t) there is a weak correlation between the output the voltage of the correlator 49 does not reach the maximum value and does not exceed the threshold level V _por1 in the threshold block 50. The key 51 does not open and false signals (interference) are simultaneously suppressed through the first ω _z1 and second ω _z2 mirror channels.

For a similar reason, false signals (interference) are simultaneously suppressed via the first ω _k1 and second ω _k2 combinational or two other combinational channels.

If a false signal (interference) is received through the direct channel at a frequency ω _CR

U _n (t) = V _n ⋅ × Cos (ω _ave t + φ _{n), n} 0≤t≤T,

then from the output of the high-frequency amplifier 30, it enters the first input of the first adder 54, is allocated by a low-pass filter 52, the tuning frequency ω _{n of} which is chosen equal to ω _n = ω _pr , and is fed to the input of the first phase inverter 53, at the output of which a voltage is generated

U _n1 (t) = - V _n × Cos (ω _ave t + φ _{n), n} 0≤t≤T,

which is fed to the second input of the first adder 54. The voltages U _p (t) and U _p1 (t) applied to the two adders 54 are compensated at its output.

Therefore, a false signal (interference) received through the direct channel at a frequency ω _p = ω _{pr5 is} suppressed using a filter plug, consisting of a narrow-band filter 52, a first phase inverter 53, a first adder 54 and implementing a phase compensation method.

If two powerful signals at frequencies ω ₁ and ω ₂ or more than two signals fall into the frequency band Δω _p1 located “to the left” of the passband Δω _{p of the} receiver, then their interaction on nonlinear elements leads to the formation of intermodulation components that fall into the passband Δω _n receiver. The tuning frequency ω _n1 and the frequency band Δω _{p1 of the} first band-pass filter 55 are selected as follows (Fig. 8):

ω _n1 = (ω ₁ + ω ₂ ) / 2, Δω _n1 = ω ₂ -ω ₁ ,

where ω ₁ , ω ₂ are the boundary frequencies that determine the frequency band Δω _p1 , hit in which two or more signals leads to the formation of intermodulation interference.

These false signals (interference) are fed to the first input of the second adder 57, separated by a band-pass filter 55, phase inverted by 180 ° by the second phase inverter and fed to the second input of the second adder 57. At the output of the latter, these false signals (interference) are compensated.

Therefore, false signals (interference) received in the frequency band Δω _p1 located "to the left" of the passband Δω _{p of the} receiver are suppressed by a filter plug consisting of the first bandpass filter 55, the second phase inverter 56, the second adder 57 and implementing the phase compensation method.

If two powerful signals at frequencies ω ₃ , ω ₄ or more than two signals fall into the frequency band Δω _p2 located to the right of the passband Δω _{p of the} receiver, then their interaction on nonlinear elements leads to the formation of intermodulation components that fall into the passband Δω _p receiver. Moreover, the tuning frequency ω _n2 and the frequency band Δω _{p2 of the} second band-pass filter 58 are selected as follows:

ω _n2 = (ω ₃ + ω ₄ ) / 2, Δω _n2 = ω ₄ -ω ₃ ,

where ω ₃ , ω ₄ are the boundary frequencies that determine the frequency band Δω _p2 , hit in which two or more signals leads to the formation of intermodulation interference

These false signals (interference) from the output of the high-frequency amplifier 30 through adders 54 and 57, which have only one arm, are fed to the first input of the third adder 60, separated by a second bandpass filter 58, 180 phase inverted by the third phase inverter 59, and fed to the second input of the third adder 60. At the output of the latter, the indicated false signals (interference) are mutually compensated.

Therefore, false signals (interference) received in the frequency band Δω _p2 located to the right of the passband Δω _{p of the} receiver are suppressed by a filter plug consisting of a second bandpass filter 58, a third phase inverter 59, a third adder 60 and implementing a phase compensation method.

Thus, the proposed system in comparison with the prototype and other technical solutions for a similar purpose provides increased selectivity and noise immunity of the receiver. This is achieved by suppressing false signals (interference) received through the direct channel at a frequency ω _p = ω _CR , in the frequency band Δω _p1 located "to the left" of the passband Δω _{p of the} receiver, and in the frequency band Δω _p2 located "to the right" from the passband Δω _{p of the} receiver. Moreover, to suppress these false signals (interference), appropriate filter plugs are used that implement the phase compensation method.

Claims (5)

An autonomous fire alarm system containing a heat starter connected in series, a current source with a pyrotechnic activator and a time relay, which is connected to the alarm device via a normally closed contact and is additionally connected to the actuator via a normally open contact, while the thermal starter and current source pyrotechnic activator structurally combined and enclosed in a housing, the thermal starter is made in the form of a spring-loaded rod, installed with the possibility of translational movement and interaction with the pyrotechnic activator of the current source, moreover, one of the end sections of the spring-loaded rod is arranged to protrude from the housing and is equipped with a latch made of material with a thermomechanical shape memory, the current source includes a shell with contact with it a pyrotechnic activator with a solid-state checker from a solid-salt, non-sessile electrochemical composition based on a lithium alloy and iron disulfide, a signal the ln device is made in the form of a signal transmitter to a remote receiver, while the signal transmitter is made in the form of serially connected master oscillator, n-tap delay line, phase inverters included in the m-taps of the n-tap delay line, adder, (n + 1) - the input which is connected to the output of the master oscillator, power amplifier and transmitting antenna, and the receiver is made in the form of series-connected receiving antenna and high-frequency amplifier, series-connected ramp generator, a first local oscillator, a first mixer, a first intermediate frequency amplifier, a correlator, a second threshold block, a second key, the second input of which is connected to the output of the first intermediate frequency amplifier, a phase doubler, a second spectrum analyzer, a comparison unit, the second input of which is connected to the first spectrum analyzer with the output of the second key, the first threshold block, the second input of which through the first delay line is connected to its output, the first key, the second input of which is connected to the output of the second key, phase a detector, the second input of which is connected through the second delay line to the output of the first switch, and the registration unit, a second local oscillator, a second mixer and a second intermediate frequency amplifier, the output of which is connected to the second input of the correlator, the control input of the sawtooth voltage generator, are connected in series to the output of the sawtooth voltage connected to the output of the first threshold block, frequency ω_g1 and ω_r2 the first and second local oscillators are spaced at twice the intermediate frequency ω _g2 -ω _g1 = 2ω _pr selected symmetrical with respect to the carrier frequency ω _{from the} received signal ω _c -ω _g1 = ω _g2 -ω _c = ω _pr and tuned synchronously, characterized in that it is equipped with a narrow-band filter, two band-pass filters, three phase inverters and three adders, and a narrow-band filter, a first phase inverter, a first adder, the second input of which is connected to the output of the high-frequency amplifier, are connected in series to the output of the high-frequency amplifier, a first bandpass filter, a second phase inverter, a second adder, the second input of which is connected to the output of the first adder, a second bandpass filter, a third phase inverter and a third adder, Torah input coupled to an output of the second adder and an output coupled to a second input of the first and second mixers.

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