An intelligent building fire alarm system

Abstract

The present invention discloses an intelligent building fire alarm system, which relates to the field of alarm technology, and includes a power supply module for power supply; a smoke detection module for smoke concentration detection; a fire judgment module for setting and adjusting the alarm threshold and making fire judgments; a sensitivity detection module for setting and adjusting the detection threshold and, when it is not determined that a fire has occurred, comparing the signal output by the smoke detection module with the size of the detection threshold; a microcontroller module for signal reception and module control; a mode switching module for signal transmission control; an upper limit detection module for setting the alarm upper limit threshold and judging whether the signal output by the smoke detection module reaches the maximum limit value; and an alarm control module for alarming. The intelligent building fire alarm system of the present invention will alarm when the detected smoke concentration exceeds the alarm threshold, and automatically adjust the sensitivity of the fire detection within a set range to avoid false alarms and improve the detection sensitivity.

Description

Technical Field

[0001] The invention relates to the technical field of alarms, in particular to an intelligent building fire alarm system. Background Art

[0002] An intelligent building refers to a building that optimizes the structure, system, service and management of the building according to the needs of the users, thereby providing users with an efficient, comfortable and convenient humanized building environment. With the increase in electricity load and gas consumption, higher and more stringent requirements are placed on the design of fire alarm systems in intelligent buildings. The fire alarm system is mainly composed of fire alarm devices and fire linkage devices. The fire alarm device is generally composed of smoke sensors, comparators, etc. After the smoke concentration exceeds the set alarm threshold, it will continue to alarm. However, the fire alarm device cannot further improve the fire detection sensitivity and has a small scope of application. Due to long-term use, the fire alarm device is easily affected by external environmental factors, such as dust, which causes the fire alarm device to automatically become high and false alarms occur frequently. Therefore, it needs to be improved. Summary of the invention

[0003] The embodiment of the present invention provides an intelligent building fire alarm system to solve the problems raised in the above background technology.

[0004] According to an embodiment of the present invention, there is provided an intelligent building fire alarm system, comprising: a power supply module, a smoke detection module, a fire judgment module, a sensitivity detection module, a microcontroller module, a mode switching module, an upper limit detection module and an alarm control module;

[0005] A power module is used to receive electric energy, stabilize the electric energy and output direct current electric energy;

[0006] a smoke detection module, connected to the power module, for receiving direct current power, for detecting smoke concentration and outputting a first detection signal;

[0007] a fire judgment module, connected to the smoke detection module and the microcontroller module, for setting an alarm threshold and outputting a first alarm signal when the first detection signal is greater than the alarm threshold, and outputting a first level signal when the first detection signal is less than the alarm threshold, for receiving a first pulse signal output by the microcontroller module and adjusting a voltage value of the alarm threshold;

[0008] a sensitivity detection module, connected to the smoke detection module, the upper limit detection module, the microcontroller module and the fire judgment module, for inverting the first level signal and transmitting the first detection signal to the upper limit detection module, for setting a detection threshold and outputting a second alarm signal when the first detection signal is greater than the detection threshold, and for receiving the first pulse signal output by the microcontroller module and adjusting the voltage value of the detection threshold;

[0009] A microcontroller module connected to the upper limit detection module, the mode switching module and the alarm control module, used for outputting a first control signal and controlling the signal transmission operation of the mode switching module, used for setting a timing duration when the first control signal is not output, and when the second alarm signal is continuously received within the timing duration, outputting a first pulse signal and adjusting the duty cycle of the first pulse signal, used for outputting a reset signal and controlling the alarm control module to stop the alarm operation, and used for receiving a third alarm signal output by the upper limit detection module and stopping the output of the reset signal and the first pulse signal;

[0010] A mode switching module, connected to the sensitivity detection module and the alarm control module, for receiving a first control signal and transmitting a second alarm signal to the alarm control module;

[0011] An upper limit detection module, used for setting an alarm upper limit threshold and outputting a third alarm signal when the first detection signal transmitted by the sensitivity detection module is greater than the alarm upper limit threshold;

[0012] The alarm control module is connected to the fire judgment module, the power supply module and the upper limit detection module, and is used to receive DC power and continue the alarm work when receiving the first alarm signal, the third alarm signal and the second alarm signal transmitted by the mode switching module, and is used to receive a reset signal and stop the alarm work.

[0013] As a further solution of the present invention: the power module includes a power interface, a power processing device and a first capacitor; the smoke detection module includes a first sensor, a first resistor and a second resistor;

[0014] Preferably, the first end of the power interface is connected to the input end of the power processing device, the output end of the power processing device is connected to the first end of the first capacitor and the VCC end of the first sensor, the OUT end of the first sensor is connected to the first end of the first resistor, the second end of the first resistor is connected to the sensitivity detection module and the fire judgment module and is connected to the GND end of the first sensor, the second end of the first capacitor, the ground end of the power processing device, the second end of the power interface and the ground end through the second resistor.

[0015] As a further solution of the present invention: the fire judgment module includes a first power supply, a third resistor, a fourth resistor, a first field effect transistor, a fifth resistor, a first comparator and a first diode; the micro control module includes a first processor;

[0016] Preferably, the in-phase end of the first comparator is connected to the second end of the first resistor, the inverting end of the first comparator is connected to the source of the first field effect transistor and to the ground through a fifth resistor, the drain of the first field effect transistor is connected to the first power supply and one end of the fourth resistor through a third resistor, the other end of the fourth resistor is connected to the gate of the first field effect transistor and the IO2 end of the first processor, the output end of the first comparator is connected to the anode of the first diode and the sensitivity detection module, and the cathode of the first diode is connected to the alarm control module.

[0017] As a further solution of the present invention: the sensitivity detection module includes a first inverter, a first path switch, a second comparator, a second power supply, a sixth resistor, a seventh resistor, a second field effect transistor, an eighth resistor, and a second diode; the micro control module also includes a clock device;

[0018] Preferably, the input end of the first inverter is connected to the output end of the first comparator, the output end of the first inverter is connected to the CTRL end of the first path switch, the IN end of the first path switch is connected to the second end of the first resistor, the OUT end of the first path switch is connected to the in-phase end of the second comparator and the upper limit detection module, the inverting end of the second comparator is connected to the cathode of the second diode, the anode of the second diode is connected to the source of the second field effect tube and is grounded through the eighth resistor, the drain of the second field effect tube is connected to the second power supply and one end of the sixth resistor through the seventh resistor, the other end of the sixth resistor is connected to the gate of the second field effect tube and the IO2 end of the first processor, and the output end of the clock device is connected to the IO5 end of the first processor.

[0019] As a further solution of the present invention: the mode switching module includes a first logic device and a third diode;

[0020] Preferably, the B end of the first logic device is connected to the output end of the second comparator, the A end of the first logic device is connected to the IO3 end of the first processor, the F end of the first logic device is connected to the anode of the third diode, and the cathode of the third diode is connected to the alarm control module.

[0021] As a further solution of the present invention: the alarm control module includes a third power supply, a ninth resistor, a first switch tube, a second switch tube, a fourth diode, a second logic device and a first speaker;

[0022] Preferably, the A end of the second logic device is connected to the cathode of the fourth diode, the first diode, the third diode and the upper limit detection module, the F end of the second logic device is connected to the anode of the fourth diode and the base of the second switch tube, the B end of the second logic device is connected to the collector of the first switch tube and is connected to the third power supply through a ninth resistor, the emitter of the first switch tube and the emitter of the second switch tube are both grounded, the collector of the second switch tube is connected to one end of the first speaker, the other end of the first speaker is connected to the output end of the power processing device, and the base of the first switch tube is connected to the IO6 end of the first processor.

[0023] As a further solution of the present invention: the upper limit detection module includes a tenth resistor, an eleventh resistor, a fourth power supply, a third comparator and a fifth diode;

[0024] Preferably, the inverting end of the third comparator is connected to one end of the eleventh resistor and is connected to the fourth power supply through the tenth resistor, the other end of the eleventh resistor is grounded, the non-inverting end of the third comparator is connected to the OUT end of the first path switch, the output end of the third comparator is connected to the anode of the fifth diode and the IO4 end of the first processor, and the cathode of the fifth diode is connected to the A end of the second logic device.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: the intelligent building fire alarm system of the present invention uses a smoke detection module to detect smoke in the environment, and a fire judgment module judges the detected smoke concentration according to a set alarm threshold, and then controls the alarm control module to perform an alarm; when the sensitivity detection module detects that the signal output by the smoke detection module exceeds the set detection threshold, and the duration of the excess is greater than the timing duration set by the microcontrol module, the microcontrol module will adjust the voltage values ​​of the alarm threshold and the detection threshold to reduce the detection sensitivity and avoid the occurrence of false alarms; after the signal output by the smoke detection module is greater than the alarm upper limit threshold provided by the upper limit detection module, an alarm is issued to improve the reliability of the fire alarm system; when high sensitivity is required, the microcontrol module can control the mode cutting module to transmit signals, the sensitivity detection module performs fire judgment, and the alarm control module issues an alarm. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0027] Figure 1 A schematic block diagram of a principle of an intelligent building fire alarm system provided by an embodiment of the present invention.

[0028] Figure 2 A circuit diagram of an intelligent building fire alarm system provided by an embodiment of the present invention.

[0029] Figure 3 A circuit diagram of an alarm control module provided in an embodiment of the present invention.

[0030] Figure 4 A circuit diagram of an upper limit detection module provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In one embodiment, see Figure 1 , an intelligent building fire alarm system, comprising: a power supply module 1, a smoke detection module 2, a fire judgment module 3, a sensitivity detection module 4, a micro control module 5, a mode switching module 6, an upper limit detection module 7 and an alarm control module 8;

[0033] Specifically, the power module 1 is used to receive electric energy, stabilize the electric energy and output direct current electric energy;

[0034] A smoke detection module 2, connected to the power module 1, for receiving direct current power, for detecting smoke concentration and outputting a first detection signal;

[0035] The fire judgment module 3 is connected to the smoke detection module 2 and the microcontroller module 5, and is used to set an alarm threshold and output a first alarm signal when the first detection signal is greater than the alarm threshold, and output a first level signal when the first detection signal is less than the alarm threshold, and is used to receive the first pulse signal output by the microcontroller module 5 and adjust the voltage value of the alarm threshold;

[0036] The sensitivity detection module 4 is connected to the smoke detection module 2, the upper limit detection module 7, the microcontroller module 5 and the fire judgment module 3, and is used for inverting the first level signal and transmitting the first detection signal to the upper limit detection module 7, and is used for setting a detection threshold and outputting a second alarm signal when the first detection signal is greater than the detection threshold, and is used for receiving the first pulse signal output by the microcontroller module 5 and adjusting the voltage value of the detection threshold;

[0037] The microcontroller module 5 is connected with the upper limit detection module 7, the mode switching module 6 and the alarm control module 8, and is used for outputting the first control signal and controlling the signal transmission operation of the mode switching module 6, and is used for setting the timing duration when the first control signal is not output, and when the second alarm signal is continuously received within the timing duration, outputting the first pulse signal and adjusting the duty cycle of the first pulse signal, and is used for outputting the reset signal and controlling the alarm control module 8 to stop the alarm operation, and is used for receiving the third alarm signal output by the upper limit detection module 7 and stopping the output of the reset signal and the first pulse signal;

[0038] A mode switching module 6, connected to the sensitivity detection module 4 and the alarm control module 8, for receiving a first control signal and transmitting a second alarm signal to the alarm control module 8;

[0039] An upper limit detection module 7 is used to set an alarm upper limit threshold and output a third alarm signal when the first detection signal transmitted by the sensitivity detection module 4 is greater than the alarm upper limit threshold;

[0040] The alarm control module 8 is connected to the fire judgment module 3, the power supply module 1 and the upper limit detection module 7, and is used to receive DC power and continue the alarm work when receiving the first alarm signal, the third alarm signal and the second alarm signal transmitted by the mode switching module 6, and is used to receive a reset signal and stop the alarm work.

[0041] In a specific embodiment, the power supply module 1 may adopt a power supply circuit composed of a power supply interface, a capacitor, etc., which may be connected to electric energy and perform voltage stabilization and filtering processing on the connected electric energy; the smoke detection module 2 may adopt a smoke detection circuit composed of a smoke sensor and a resistor, which may detect the concentration of smoke in the environment; the fire judgment module 3 may adopt a fire judgment circuit composed of a resistor, a comparator, a field effect transistor, etc., which may set an alarm threshold, which is used to determine whether the detected smoke concentration reaches the smoke concentration during a fire. When the detected signal is greater than the alarm threshold, it is determined that a fire has occurred and the alarm control module 8 is controlled to alarm, and the voltage of the alarm threshold may be adjusted by the microcontroller module 5. The alarm threshold has a maximum value and a minimum value, and the maximum value and the minimum value of the alarm threshold are respectively the maximum value and the minimum value of the signal output by the smoke detection module 2; the sensitivity detection module 4 may adopt a sensitivity detection circuit composed of an inverter, an analog switch, a comparator, etc., which may set a detection threshold, and when the fire judgment module 3 does not determine that a fire has occurred, detect the relationship between the signal output by the smoke detection module 2 and the detection threshold, and the detection threshold The value is obtained after the alarm threshold voltage drops, and the sensitivity of the smoke detection module 2 is judged when the fire is not judged. The above-mentioned micro-control module 5 can adopt a micro-control circuit composed of a single-chip microcomputer and a clock device. The single-chip microcomputer integrates many components such as an arithmetic unit, a controller, a memory, and an input and output device to realize signal processing, data storage, module control, timing control and other functions, and realize signal reception and module control. The clock device can provide a clock signal for the single-chip microcomputer, and then set the timing duration. The sensitivity of the smoke detection module 2 is judged by the duration of the output signal of the sensitivity detection module 4 received; the above-mentioned mode switching module 6 can adopt a mode switching circuit composed of a logic device and a diode, which can cooperate with the sensitivity detection module 4 to perform high-sensitivity fire detection; the above-mentioned upper limit detection module 7 can adopt an upper limit detection circuit composed of a resistor, a comparator, etc., to provide an alarm upper limit threshold, and the alarm upper limit threshold is less than the maximum value of the alarm threshold, which can determine whether the smoke detection module 2 can perform smoke detection normally; the above-mentioned alarm control module 8 can adopt an alarm control circuit composed of a logic device, a diode, a speaker, etc., which can perform self-locking alarm and alarm reset.

[0042] In another embodiment, see Figure 1 , Figure 2 , Figure 3 and Figure 4 , the power module 1 includes a power interface, a power processing device and a first capacitor C1; the smoke detection module 2 includes a first sensor IC1, a first resistor R1 and a second resistor R2;

[0043] Specifically, the first end of the power interface is connected to the input end of the power processing device, the output end of the power processing device is connected to the first end of the first capacitor C1 and the VCC end of the first sensor IC1, the OUT end of the first sensor IC1 is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the sensitivity detection module 4 and the fire judgment module 3 and is connected to the GND end of the first sensor IC1, the second end of the first capacitor C1, the ground end of the power processing device, the second end of the power interface and the ground end through the second resistor R2.

[0044] In a specific embodiment, the power processing device may be composed of a LM317 voltage regulator to perform voltage stabilization on the input electric energy; the first sensor IC1 may be a gas sensor to detect smoke and the output voltage increases with the increase of smoke concentration.

[0045] Further, the fire judgment module 3 includes a first power supply VCC1, a third resistor R3, a fourth resistor R4, a first field effect transistor Q1, a fifth resistor R5, a first comparator A1 and a first diode D1; the micro control module 5 includes a first processor U1;

[0046] Specifically, the in-phase end of the first comparator A1 is connected to the second end of the first resistor R1, the inverting end of the first comparator A1 is connected to the source of the first field effect transistor Q1 and is connected to the ground end through the fifth resistor R5, the drain of the first field effect transistor Q1 is connected to the first power supply VCC1 and one end of the fourth resistor R4 through the third resistor R3, the other end of the fourth resistor R4 is connected to the gate of the first field effect transistor Q1 and the IO2 end of the first processor U1, the output end of the first comparator A1 is connected to the anode of the first diode D1 and the sensitivity detection module 4, and the cathode of the first diode D1 is connected to the alarm control module 8.

[0047] In a specific embodiment, the first field effect transistor Q1 can be an N-channel field effect transistor, which cooperates with the first power supply VCC1, the third resistor R3, the fourth resistor R4 and the fifth resistor R5 to provide an alarm threshold; the first comparator A1 can be an LM358 comparator; the first processor U1 can be an STM32 microcontroller.

[0048] Further, the sensitivity detection module 4 includes a first inverter U3, a first path switch U2, a second comparator A2, a second power supply VCC2, a sixth resistor R6, a seventh resistor R7, a second field effect transistor Q2, an eighth resistor R8, and a second diode D2; the micro control module 5 also includes a clock device;

[0049] Specifically, the input end of the first inverter U3 is connected to the output end of the first comparator A1, the output end of the first inverter U3 is connected to the CTRL end of the first path switch U2, the IN end of the first path switch U2 is connected to the second end of the first resistor R1, the OUT end of the first path switch U2 is connected to the in-phase end of the second comparator A2 and the upper limit detection module 7, the inverting end of the second comparator A2 is connected to the cathode of the second diode D2, the anode of the second diode D2 is connected to the source of the second field effect transistor Q2 and is grounded through the eighth resistor R8, the drain of the second field effect transistor Q2 is connected to the second power supply VCC2 and one end of the sixth resistor R6 through the seventh resistor R7, the other end of the sixth resistor R6 is connected to the gate of the second field effect transistor Q2 and the IO2 end of the first processor U1, and the output end of the clock device is connected to the IO5 end of the first processor U1.

[0050] In a specific embodiment, the first inverter U3 may use a NOT gate chip to invert the input low-level signal; the first path switch U2 may use a CD4066 chip; the second field effect transistor Q2 may use an N-channel field effect transistor, which cooperates with the second power supply VCC2, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8 and the second diode D2 to provide a detection threshold, wherein the signal voltage output by the second field effect transistor Q2 in cooperation with the sixth resistor R6, the seventh resistor R7, the second power supply VCC2 and the eighth resistor R8 is the same as the signal voltage output when the first field effect transistor Q1, the first power supply VCC1, the third resistor R3, the fourth resistor R4 and the fifth resistor R5 are connected; the second comparator A2 may use an LM358 comparator; the clock device may use a DS1302 clock chip to provide clock information for the first processor U1.

[0051] Further, the mode switching module 6 includes a first logic device J1 and a third diode D3;

[0052] Specifically, the B end of the first logic device J1 is connected to the output end of the second comparator A2, the A end of the first logic device J1 is connected to the IO3 end of the first processor U1, the F end of the first logic device J1 is connected to the anode of the third diode D3, and the cathode of the third diode D3 is connected to the alarm control module 8.

[0053] In a specific embodiment, the first logic device J1 can be an AND gate chip.

[0054] Further, the alarm control module 8 includes a third power supply VCC3, a ninth resistor R9, a first switch tube VT1, a second switch tube VT2, a fourth diode D4, a second logic device J2 and a first speaker BL;

[0055] Specifically, the A end of the second logic device J2 is connected to the cathode of the fourth diode D4, the first diode D1, the third diode D3 and the upper limit detection module 7, the F end of the second logic device J2 is connected to the anode of the fourth diode D4 and the base of the second switch tube VT2, the B end of the second logic device J2 is connected to the collector of the first switch tube VT1 and is connected to the third power supply VCC3 through the ninth resistor R9, the emitter of the first switch tube VT1 and the emitter of the second switch tube VT2 are both grounded, the collector of the second switch tube VT2 is connected to one end of the first speaker BL, the other end of the first speaker BL is connected to the output end of the power processing device, and the base of the first switch tube VT1 is connected to the IO6 end of the first processor U1.

[0056] In a specific embodiment, the second logic device J2 can use an AND gate chip, which cooperates with the fourth diode D4, the ninth resistor R9 and the third power supply VCC3 to perform self-locking processing on the high-level signal input to the A terminal of the second logic device J2; the first switch tube VT1 and the second switch tube VT2 can both use NPN transistors.

[0057] Further, the upper limit detection module 7 includes a tenth resistor R10, an eleventh resistor R11, a fourth power supply VCC4, a third comparator A3 and a fifth diode D5;

[0058] Specifically, the inverting end of the third comparator A3 is connected to one end of the eleventh resistor R11 and is connected to the fourth power supply VCC4 through the tenth resistor R10, the other end of the eleventh resistor R11 is grounded, the non-inverting end of the third comparator A3 is connected to the OUT end of the first path switch U2, the output end of the third comparator A3 is connected to the anode of the fifth diode D5 and the IO4 end of the first processor U1, and the cathode of the fifth diode D5 is connected to the A end of the second logic device J2.

[0059] In a specific embodiment, the fourth power supply VCC4, the tenth resistor R10 and the eleventh resistor R11 provide an upper alarm threshold; the third comparator A3 can be a LM358 comparator.

[0060] In a fire alarm system for an intelligent building according to the present embodiment, electric energy is connected to the power interface, the power processing device and the first capacitor C1 perform voltage stabilization and filtering processing, the first sensor IC1 detects the smoke situation in the environment, and when the IO2 end of the first processor U1 does not control the conduction of the first field effect transistor Q1 and the second field effect transistor Q2, the first field effect transistor Q1 is controlled by the first power supply VCC1 and the fourth resistor R4, and the second field effect transistor Q2 is controlled by the sixth resistor R6 and the second power supply VCC2. At this time, the first power supply VCC1, the third resistor R3, the first field effect transistor Q1 and the fifth resistor R5 provide an alarm threshold, and the voltage provided by the second power supply VCC2, the seventh resistor R7, the second field effect transistor Q2 and the eighth resistor R8 is consistent with the alarm threshold. The voltage of the threshold is the same, and the second diode D2 performs a voltage drop process to provide a detection threshold. The signal output by the first sensor IC1 is divided by the first resistor R1 and the second resistor R2, and the signal is compared with the alarm threshold to determine whether a fire has occurred. Since the sensitivity is not high at this time, weak smoke cannot be detected, and the first comparator A1 will output a low level. At this time, if a higher sensitivity fire detection is required, IO3 of the first processor U1 will control the A terminal of the first logic device J1 to maintain a high level. Since the first comparator A1 outputs a low level, the first inverter U3 triggers the IN terminal and OUT terminal of the first path switch U2 to be turned on after inversion processing, so as to transmit the divided signal to the second comparator A2. The comparator A2 cooperates with the detection threshold to determine whether a fire occurs at this time. When a fire occurs, the divided signal is greater than the detection threshold. The second comparator A2 provides a high-level signal to the A terminal of the second logic device J2, cooperates with the fourth diode D4, the ninth resistor R9 and the third power supply VCC3 to perform high-level self-locking, and triggers the second switch tube VT2 to turn on, so that the first speaker BL alarms. If a high-sensitivity fire detection is not required at this time, the IO3 terminal of the first processor U1 stops outputting a high-level signal, and the alarm threshold is used as the fire detection limit. When the divided signal is greater than the alarm threshold, it is determined that a fire occurs, and the alarm control module 8 performs a self-locking alarm. When it is determined that no fire occurs, the first comparator A1 outputs a low level, and the first path switch U 2 is turned on, and the second comparator A2 determines whether the divided signal is greater than the detection threshold. When the divided signal is greater than the detection threshold, the second comparator A2 outputs a high-level signal. If the duration of the high-level signal output by the second comparator A2 exceeds the timing duration set by the first processor U1 and the clock device, the IO2 end of the first processor U1 will adjust the duty cycle of the output pulse signal, change the conduction degree of the first field effect tube Q1 and the second field effect tube Q2, change the voltage value of the alarm threshold and the detection threshold, reduce the sensitivity of fire detection, and avoid the signal output by the first sensor IC1 being affected by factors such as dust in the environment when no fire is determined to have occurred, so that the voltage of the divided signal increases, thereby increasing the sensitivity of fire detection.In the case of a false alarm, when the signal transmitted by the first path switch U2 is greater than the alarm upper threshold provided by the fourth power supply VCC4, the tenth resistor R10 and the eleventh resistor R11, the third comparator A3 outputs a high level, which means that the adjusted alarm threshold reaches the maximum allowable voltage value, that is, the maximum voltage value that the smoke detection module 2 can output. At this time, the third comparator A3 will directly control the alarm control module 8 to alarm, and the first processor U1 stops working, wherein the IO6 terminal of the first processor U1 can stop the alarm control module 8 from alarming by controlling the conduction of the first switch tube VT1.

[0061] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0062] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An intelligent building fire alarm system, characterized in that: The intelligent building fire alarm system includes: a power supply module, a smoke detection module, a fire judgment module, a sensitivity detection module, a microcontroller module, a mode switching module, an upper limit detection module and an alarm control module; The power module is used to receive electric energy, stabilize the electric energy and output direct current electric energy; The smoke detection module is connected to the power supply module and is used to receive direct current power, detect smoke concentration and output a first detection signal; The fire judgment module is connected to the smoke detection module and the microcontroller module, and is used to set an alarm threshold and output a first alarm signal when the first detection signal is greater than the alarm threshold, and output a first level signal when the first detection signal is less than the alarm threshold, and is used to receive a first pulse signal output by the microcontroller module and adjust the voltage value of the alarm threshold; The sensitivity detection module is connected to the smoke detection module, the upper limit detection module, the microcontroller module and the fire judgment module, and is used to invert the first level signal and transmit the first detection signal to the upper limit detection module, to set a detection threshold and output a second alarm signal when the first detection signal is greater than the detection threshold, and to receive the first pulse signal output by the microcontroller module and adjust the voltage value of the detection threshold; The alarm threshold is used to determine whether the detected smoke concentration reaches the smoke concentration during a fire; the detection threshold is obtained after the alarm threshold voltage drops; The microcontrol module is connected to the upper limit detection module, the mode switching module and the alarm control module, and is used to output a first control signal and control the signal transmission work of the mode switching module when a higher sensitivity of fire detection is required, and is used to set a timing duration during the period when the first control signal is not output, and when the second alarm signal is continuously received within the timing duration, output a first pulse signal and adjust the duty cycle of the first pulse signal and change the voltage value of the alarm threshold and the detection threshold to reduce the sensitivity of fire detection, and is used to output a reset signal and control the alarm control module to stop the alarm work, and is used to receive a third alarm signal output by the upper limit detection module and stop outputting the reset signal and the first pulse signal; The mode switching module is connected to the sensitivity detection module and the alarm control module, and is used to receive the first control signal and transmit the second alarm signal to the alarm control module; The upper limit detection module is used to set an alarm upper limit threshold and output a third alarm signal when the first detection signal transmitted by the sensitivity detection module is greater than the alarm upper limit threshold; The alarm control module is connected to the fire judgment module, the power supply module and the upper limit detection module, and is used to receive direct current power and continue to perform alarm work when receiving the first alarm signal, the third alarm signal and the second alarm signal transmitted by the mode switching module, and is used to receive a reset signal and stop the alarm work; The fire judgment module includes a first power supply, a third resistor, a fourth resistor, a first field effect transistor, a fifth resistor, a first comparator and a first diode; the micro control module includes a first processor; The in-phase end of the first comparator is connected to the second end of the first resistor of the smoke detection module, the inverting end of the first comparator is connected to the source of the first field effect tube and connected to the ground end through the fifth resistor, the drain of the first field effect tube is connected to the first power supply and one end of the fourth resistor through the third resistor, the other end of the fourth resistor is connected to the gate of the first field effect tube and the IO2 end of the first processor, the output end of the first comparator is connected to the anode of the first diode and the sensitivity detection module, and the cathode of the first diode is connected to the alarm control module; The sensitivity detection module includes a first inverter, a first path switch, a second comparator, a second power supply, a sixth resistor, a seventh resistor, a second field effect transistor, an eighth resistor, and a second diode; the micro control module also includes a clock device; The input end of the first inverter is connected to the output end of the first comparator, the output end of the first inverter is connected to the CTRL end of the first path switch, the IN end of the first path switch is connected to the second end of the first resistor of the smoke detection module, the OUT end of the first path switch is connected to the in-phase end of the second comparator and the upper limit detection module, the inverting end of the second comparator is connected to the cathode of the second diode, the anode of the second diode is connected to the source of the second field effect tube and grounded through the eighth resistor, the drain of the second field effect tube is connected to the second power supply and one end of the sixth resistor through the seventh resistor, the other end of the sixth resistor is connected to the gate of the second field effect tube and the IO2 end of the first processor, and the output end of the clock device is connected to the IO5 end of the first processor; The mode switching module includes a first logic device and a third diode; The B terminal of the first logic device is connected to the output terminal of the second comparator, the A terminal of the first logic device is connected to the IO3 terminal of the first processor, the F terminal of the first logic device is connected to the anode of the third diode, and the cathode of the third diode is connected to the alarm control module; The alarm control module includes a third power supply, a ninth resistor, a first switch tube, a second switch tube, a fourth diode, a second logic device and a first speaker; The A end of the second logic device is connected to the cathode of the fourth diode, the first diode, the third diode and the upper limit detection module, the F end of the second logic device is connected to the anode of the fourth diode and the base of the second switch tube, the B end of the second logic device is connected to the collector of the first switch tube and connected to the third power supply through the ninth resistor, the emitter of the first switch tube and the emitter of the second switch tube are both grounded, the collector of the second switch tube is connected to one end of the first speaker, the other end of the first speaker is connected to the output end of the power processing device of the power module, and the base of the first switch tube is connected to the IO6 end of the first processor; The upper limit detection module includes a tenth resistor, an eleventh resistor, a fourth power supply, a third comparator and a fifth diode; The inverting end of the third comparator is connected to one end of the eleventh resistor and is connected to the fourth power supply through the tenth resistor, the other end of the eleventh resistor is grounded, the non-inverting end of the third comparator is connected to the OUT end of the first path switch, the output end of the third comparator is connected to the anode of the fifth diode and the IO4 end of the first processor, and the cathode of the fifth diode is connected to the A end of the second logic device.

2. The intelligent building fire alarm system according to claim 1, characterized in that: The power module includes a power interface, a power processing device and a first capacitor; the smoke detection module includes a first sensor, a first resistor and a second resistor; The first end of the power interface is connected to the input end of the power processing device, the output end of the power processing device is connected to the first end of the first capacitor and the VCC end of the first sensor, the OUT end of the first sensor is connected to the first end of the first resistor, the second end of the first resistor is connected to the sensitivity detection module and the fire judgment module and is connected to the GND end of the first sensor, the second end of the first capacitor, the ground end of the power processing device, the second end of the power interface and the ground end through the second resistor.

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