RU2032225C1 - Fire detector - Google Patents

Abstract

FIELD: fire protection facilities. SUBSTANCE: fire detector has optical chamber 1 with radiators 2 and 3, photodetectors 4 and 5, radiator lens 6, photodetector lens 7, control pulse shaper 8, decoder 9, selector 10, amplifier 11, synchronous counter 12, coder 13, optical indicator 14 and connection unit 15. To check serviceability of fire detector series of negative polarity pulses are supplied from receiving and checking device along line simulating pulse disconnection of supply in line. These pulses initiate operation of radiator 3 and photodetector 5 through selector 10 and decoder 9. Optical radiation from radiator 2 gets on additional photodetector 5, electric signal from the latter passes to additional radiator 3, optical radiation from the latter gets on photodetector 4 simulating radiation dissipated by smoke. Fire detector in good repair will send FIRE ALARM signal, thus proving its serviceability. EFFECT: provision of serviceability check device and fire address shaper indicating place of fire location. 3 cl, 2 dwg

Description

 The present invention relates to fire alarm devices designed to protect objects from fire with an indication of the location of the fire.

 Known smoke detector [1], consisting of a sensor unit, an electronic signal processing circuit and an address unit that converts the signal with the assignment of a detector code to it.

 The disadvantage of the detector is the lack of verification of its operability, which reduces the reliability of the detector, which is most clearly manifested in fire alarm systems, combining tens and hundreds of fire detectors.

 Closest to the proposed one is a smoke detector [2] containing a modulator, a primary and secondary light sources connected to it, one photocell is located on the same axis as the main light source, the other photocell is at an angle to it, a filter is connected in series with each of the photocells, amplifier and detector, detector outputs are connected to a control relay, which is connected to a signal device, and a control button connected to a power source, the main and additional light sources are connected in series Separately, and in parallel with an additional light source, a key is turned on, with a control button connected to its control input.

 The disadvantage of this smoke detector is its unsatisfactory reliability, due to the manual inclusion of a health check, as well as the lack of information about the "address" of the detector when the alarm is turned on.

 For this purpose, a fire detector containing a camera in which two mutually intersecting optical chains from a radiation source, a lens and a photodetector are placed, a photodetector of the first chain is connected to an amplifier, a connection unit and an optical indicator, a decoder, shaper, selector, encoder and synchronous counter are introduced the first input of which is connected to the amplifier output, the second input is with the first output of the driver, the third input is with the first output of the selector, the output is with the first input of the optical indicator and the first input is a cipher torus, the second input of the encoder is connected to the second output of the shaper, the first output is to the first input of the selector, and through the connection block to the communication line, the second input of the selector is connected to the communication line, and the third input is connected to the third output of the shaper, the fourth output of which is connected to the source radiation of the second optical chain, the fifth output is to the first input of the decoder, and the input to the second output of the selector, the third output of which is connected to the second input of the decoder and to the fourth input of the synchronous counter, the output of the decoder is connected to the source radiation source of the first optical chain, which is connected to the photodetector of the second optical chain, the fourth input of the selector is connected to the second output of the encoder, the third input of which is connected to the sixth output of the shaper, the seventh output of which is connected to the fifth input of the synchronous counter, and the eighth output to the sixth input of the synchronous counter.

 In FIG. 1 shows a diagram of a fire detector; in FIG. 2 - diagrams of the electrical voltage of the elements.

 The detector consists of an optical camera 1 containing radiation sources 2 and 3, photodetectors 4 and 5, a radiation source lens 6, a photodetector lens 7, as well as a shaper 8, a decoder 9, a selector 10, an amplifier 11, a synchronous counter 12, an encoder 13, optical indicator 14 and block 15 connection.

 In the absence of smoke in the optical chamber 1 and a constant voltage value in the line, the fire detector consumes an electric current of a small value (0.1 mA), which is necessary for the normal operation of the elements of the electrical circuit. The radiation source 2 through the lens 6 sends light pulses, for example, with a frequency of 1 Hz and a duration of 50 μs to the optical camera 1, which do not fall on the photodetector 4, and the detector is in standby mode.

 When smoke appears in the optical chamber 1, the radiation scattered by it through the lens 7 is fed to a photodetector 4, the electrical pulses of which are fed through an amplifier 11 to a synchronous counter 12. When five consecutive pulses arrive at a synchronous counter 12, it includes an optical indicator 14 and an encoder 13, which transmits to the connection unit 15, a double set of pulse-width modulated pulses containing information about the detector number in binary code, set by the built-in switch. The number "0" corresponds to a short pulse, the number "1" - the pulse is 8 times longer. The connection block 15 opens synchronously with the incoming pulses and reduces the voltage in the line by about 2 times, which is recorded by the control panel (PKP) as a "Fire" signal. A double set of pulses is necessary to identify possible interference with the transmission of electrical signals through the line by comparing the first and second half of the transmitted information in the control panel. If the information of the first half of the second half of the pulses does not match, the control panel disconnects the voltage in the line for a short period of time. The specified signal through the selector 10 is fed to the shaper, setting it to its original state, and to the synchronous counter 12, the signal from which re-enables the encoder 13 to transmit address information. This process will be repeated until the first and second halves of the pulse set are accepted as identical.

 To test the detector’s operability, a series of pulses of negative polarity (pulse disconnection of electric power in the line) are received from the control panel via the line to the detector, which connect the radiation source 3 and the photodetector 5 through the selector 10 and the decoder 9. In this case, the optical radiation from the radiation source 2 enters the additional photodetector 5, the electric signal from which enters the additional radiation source 3, the optical radiation of which is fed to the photodetector 4, simulating smoke scattered radiation. As a result of this, a working detector transmits a "Fire" signal confirming its operability.

 Shaper 8 consists of a master pulse generator (D1-D3), a frequency divider (C1, C2), a pulse shaper for controlling a synchronous counter (T1) and a pulse shaper for a radiation source 2 - a two-input element 2OR-NOT (D4).

 The decoder 9 consists of two counters (CT3, CT4).

 The selector 10 consists of a trigger (T2), a two-input element 2 OR-NOT (D5), a three-input element 3 OR-NOT (D6), a capacitor (C1) and a resistor (R1).

 The amplifier 11 is made on an operational amplifier V1.

 Synchronous counter 12 consists of a counter (CT5), two triggers (T3, T4) and a two-input element 2OR-NOT (D7).

 The encoder 13 consists of a multiplexer (MX1), three counters (CT6-CT8) and a device code - a set of keys (K1), the number of which corresponds to the capacity of the maximum detector address number.

 The optical indicator 14 consists of a two-input element 2OR-NOT (D8) and a radiation source - LED (HL1).

 The connection block 15 consists of a transistor VT1 and elements R, D and C, providing electric power to the detector from the line.

 The generator D1-D3 generates electrical pulses with a duration of, for example, 50 μs and a repetition period of 5 ms. At the outputs 1, 2, 4, 8, 16, 32, 64, 128 counters CT1, CT2, respectively, pulses are generated with a duty cycle of Q = 2 and a period of 10 ms, 20 ms, 40 ms, 80 ms, 160 ms, 320 ms, 640 ms, 1.28 s. At the outputs of the trigger T1 pulses are generated with a duration of 5 ms with a period of 1.28 s. At the output of element D4, pulses are generated with a duration of 50 μs with a period of 1.28 s, which are supplied to the radiation source 2.

 In the absence of smoke in the optical chamber 1, there are no electric pulses from the photodetector 4, therefore, trigger T3, counter ST5, and trigger T4 are in the zero state, the indicator HL1 is off, the counter ST6, ST7, ST8 are in the zero state and a logic signal zero at which the key VT1 is closed and the detector does not transmit any information.

 In the presence of smoke in the optical chamber 1, electric pulses from the photodetector 4 through the amplifier V1 and element D7 are fed to the D-input of the trigger T3 synchronously with the pulses arriving at the C-input of the trigger T3, which switches it to the state Q = 1. After this, the ST5 counter starts counting the pulses arriving at its input from the direct output of the T1 trigger, which have a period of 1.28 s, and after 4 pulses, the logical 1 signal arriving at the D-input of the T4 trigger appears on the 4 output of the ST5 counter, due to why the trigger T4 enters the state Q = 1, turning on the optical indicator through the D8 element in the pulse mode, allowing the counters ST6 and ST7, which control the multiplexer MX1 and the counter ST8, to form a "burst" of pulses, corresponding to the code number of the detector, which sets the key E K1. The formation of pulses occurs until the signal "1" appears on the output 32 of the CT7 counter, which stops the ST6, ST7 counters and blocks the D6 element. In case of distortion of information transmitted by the detector (for example, induced by electromagnetic interference to the connecting line), the control panel makes a pulsed shutdown of the electric voltage in the line, which, through the capacitor C1 and element D6, sets the T4 trigger to the state Q = 0, which sets the CT6 counters to their initial state and CT7, after which the trigger switches back to the state Q = 1 and the encoder 13 will repeat the transmission of the Fire address information.

 To reset the “Fire” signal, the control panel turns off the power supply voltage in the line for a while, for example, 2 s. In this case, the trigger T2 enters the state Q = 0 and the signal “0” appears through the element D7 at the D-input of the trigger T3, and due to the resetting of the counters ST1 and CT2 through the element D5, a pulse will arrive at the C-input of the trigger T3 through 1.28 s, switching trigger T3 to the state Q = 0, which puts the entire detector in standby mode.

 When requesting the health of the detectors, the control panel transmits eight impulses of zeroing the supply voltage to the detectors in the line with a period of 1 s. These pulses through the trigger T2 in the form of a logical "1" are fed to the R-input of the counter CT3 of the decoder 9 and each time set it to the zero state, preventing the output of signal 2 from the logical "1". This ensures the operation of the CT4 counter, at the output of 8 of which, after 8 s, a logical “1” signal appears, providing electrical connection between the photodetector 5 and the radiation source 3 illuminating the photodetector 4, which triggers a working detector and sends the Fire signal to the control panel.

Claims (3)

 1. A fire detector containing a camera in which two mutually intersecting optical chains from a radiation source, a lens and a photodetector are placed, a photodetector of the first chain is connected to an amplifier, a connection unit and an optical indicator, characterized in that a decoder, shaper, selector are inserted into it, encoder and synchronous counter, the first input of which is connected to the amplifier output, the second input - with the first output of the driver, the third input - with the first output of the selector, the output - with the first inputs of the optical indicator and a radiator, the second input of the encoder is connected to the second output of the shaper, the first output is connected to the first input of the selector and through the connection block to the communication line, the second input of the selector is connected to the communication line, and the third input is connected to the third output of the shaper, the fourth output of which is connected to the radiation source the second optical chain, the fifth output to the first input of the decoder, and the input to the second output of the selector, the third output of which is connected to the second input of the decoder and the fourth input of the synchronous counter, the output of the decoder is connected to and the radiation source of the first optical chain, which is connected to the photodetector of the second optical chain, the fourth selector input is connected to the second output of the encoder, the third input of which is connected to the sixth output of the driver, the seventh output of which is connected to the fifth input of the synchronous counter, and the eighth output to the sixth input of the synchronous counter and the second input of the optical indicator.  2. The detector according to claim 1, characterized in that the synchronous counter contains a counter, two triggers and an OR element - NOT, the output of which is connected to the D-input of the first trigger, whose inverse output is connected to the R-input of the counter, the fourth output of which is connected to own C-input and to the D-input of the second trigger, the first input of the synchronous counter is the first input of the OR element - NOT, the second input is the input of the counter, the third input is the R-input of the second trigger, the fourth input is the second input of the OR element - NOT, fifth input - C-input of the second trigger, the sixth input ohm - C-input of the first flip-flop inverse output of the second flip-flop is the output of the synchronous counter.  3. The detector according to claim 1, characterized in that the selector contains two OR elements - NOT, a resistor, a capacitor and a trigger, the inverse output of which is connected to the first inputs of the first and second elements OR - NOT, the second inputs of which are combined and connected to the power terminal and one capacitor plate, the second plate of which is connected to the trigger D-input, the R-input of which is the first input of the selector, the D-input is the second input of the selector, the third input is the C-input of the second trigger, the fourth input is the first input of the second element OR - NOT first exit the selector is the output of the sixth element OR - NOT.

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