Intelligent NB-IoT independent smoke fire detection alarm

Abstract

The present disclosure provides an intelligent NB-IoT independent smoke fire detection alarm, which belongs to the field of fire detection technology. The intelligent NB-IoT independent smoke fire detection alarm includes a fire sensor, a switch module, a first temperature compensation module, a signal amplification module, a second temperature compensation module and a main control unit; the switch module is connected to the fire sensor, the switch module is used to power the fire sensor, and the fire sensor is used to detect fire; the first temperature compensation module is connected to the switch module, and the first temperature compensation module is used to perform temperature compensation for the switch module; the fire sensor is connected to the first end of the signal amplification circuit, the second end of the signal amplification circuit is connected to the main control unit, the second temperature compensation module is connected to the third end of the signal amplification module, and the second temperature compensation module performs temperature compensation for the fire sensor. The present disclosure can solve the problem of false alarm or missed alarm in existing fire detection alarms.

Description

Technical Field

[0001] The present disclosure relates to the field of fire detection technology, and in particular to an intelligent NB-IoT independent smoke fire detection alarm. Background Art

[0002] With the continuous development of Internet of Things technology, intelligent fire detection alarms based on narrowband Internet of Things (NB-IoT) have gradually become a new trend in the industry. NB-IoT technology, with its advantages of low power consumption, wide coverage, and large connections, provides reliable technical support for remote monitoring and real-time communication of fire detection alarms.

[0003] However, the existing NB-IoT fire detection alarm may affect the performance of the fire detection module when the ambient temperature changes, resulting in false alarms or missed alarms in the fire detection alarm. Summary of the invention

[0004] The disclosed embodiment provides an intelligent NB-IoT independent smoke fire detection alarm to solve the problem of false alarm or missed alarm of existing fire detection alarms.

[0005] In a first aspect, an embodiment of the present disclosure provides an intelligent NB-IoT independent smoke fire detection alarm, including a fire sensor, a switch module, a first temperature compensation module, a signal amplification module, a second temperature compensation module, a main control unit and a remote communication module;

[0006] The switch module is connected to the fire sensor, the switch module is used to supply power to the fire sensor, and the fire sensor is used to detect fire;

[0007] The first temperature compensation module is connected to the switch module, and the first temperature compensation module is used to perform temperature compensation for the switch module;

[0008] The fire sensor is connected to a first end of the signal amplifying circuit, a second end of the signal amplifying circuit is connected to the main control unit, the second temperature compensation module is connected to a third end of the signal amplifying module, and the second temperature compensation module performs temperature compensation for the fire sensor;

[0009] The main control unit is connected to the monitoring terminal through a remote communication module.

[0010] In an exemplary embodiment of the present disclosure, a signal filtering module is also included;

[0011] The first end of the signal filtering module is connected to the first end of the signal amplifying module, and the second end of the signal filtering module is connected to the main control unit.

[0012] In an exemplary embodiment of the present disclosure, the switch module includes: a resistor R2, a capacitor C1, a transistor Q1, a resistor R1 and a variable resistor RP1;

[0013] The first end of the resistor R2 is connected to the VCC power supply, the second end of the resistor R2 is connected to the base of the transistor Q1, and the base of the transistor Q1 is grounded through the resistor R1;

[0014] The first end of the capacitor C1 is connected to the VCC power supply, and the second end of the capacitor C1 is connected to the base of the transistor Q1;

[0015] The collector of the transistor Q1 is connected to the first end of the variable resistor RP1, the second end of the variable resistor RP1 is connected to the VCC power supply, the emitter of the transistor Q1 is connected to the power supply end of the fire sensor, the ground end of the fire sensor is grounded, and the output end of the fire sensor is connected to the first end of the signal amplification module.

[0016] In an exemplary embodiment of the present disclosure, the first temperature compensation module includes a diode D2;

[0017] The anode of the diode D2 is connected to the second end of the resistor R2 , and the cathode of the diode D2 is connected to the base of the transistor Q1 .

[0018] In an exemplary embodiment of the present disclosure, a constant current module is also included;

[0019] The constant current modules are respectively connected to the switch modules, and are used to provide a stable working current for the fire sensor.

[0020] In an exemplary embodiment of the present disclosure, the constant current module includes a transistor Q2, a resistor R8 and an optical coupler OC1;

[0021] The base of the transistor Q2 is connected to the emitter of the transistor Q1, the collector of the transistor Q2 is grounded, the emitter of the transistor Q2 is connected to the first input end of the optocoupler OC1 through the resistor R8, the second input end of the optocoupler OC1 is connected to the VDD power supply, the first output end of the optocoupler OC1 is connected to the VCC power supply, and the second output end of the optocoupler OC1 is connected to the second end of the variable resistor RP1.

[0022] In an exemplary embodiment of the present disclosure, the signal amplification module includes a resistor R4, a capacitor C3, an amplifier U3, a resistor R5, and a resistor R6;

[0023] The first end of the resistor R4 serves as the first end of the signal amplification module, the second end of the resistor R4 is grounded through the capacitor C3, the second end of the resistor R4 is connected to the in-phase input end of the amplifier U3, the inverting input end of the amplifier U3 is grounded through the resistor R5, the output end of the amplifier U3 is connected to the inverting input end of the amplifier U3 through the resistor R6, and the output end of the amplifier U3 is connected to the main control unit.

[0024] In an exemplary embodiment of the present disclosure, the second temperature compensation module includes a resistor R11, a resistor R12, a resistor R13, a thermistor RT, an amplifier U4, and a resistor R10;

[0025] The first end of the resistor R11 is connected to the VCC power supply, the second end of the resistor R11 is grounded through the resistor R13, the first end of the resistor R12 is connected to the VCC power supply, the second end of the resistor R12 is grounded through the thermistor RT, the second end of the resistor R11 is connected to the inverting input end of the amplifier U4, the second end of the resistor R12 is connected to the non-inverting input end of the amplifier U4, the output end of the amplifier U4 is connected to the inverting input end of the amplifier U4 through the resistor R10, the output end of the amplifier U4 is connected to the inverting input end of the amplifier U3, and the inverting input end of the amplifier U3 serves as the third end of the signal amplification module.

[0026] In an exemplary embodiment of the present disclosure, it also includes a field alarm module;

[0027] The on-site alarm module is connected to the main control unit.

[0028] The beneficial effects of the intelligent NB-IoT independent smoke fire detection alarm provided by the embodiment of the present disclosure are: by integrating a precise temperature compensation mechanism and an efficient signal amplification strategy, the accuracy and stability of fire detection in complex environments of the embodiment of the present disclosure are significantly enhanced. The use of the fire sensor in conjunction with the dual temperature compensation module (i.e., the first temperature compensation module and the second temperature compensation module) effectively solves the problem of false alarms and missed alarms caused by temperature changes, ensuring that the sensor can stably output reliable signals at different temperatures. The addition of the signal amplification module further enhances the signal processing capability, improves the accuracy of the main control unit in identifying fire signals, and reduces the impact of external interference. Combined with remote communication technology, the embodiment of the present disclosure can instantly transmit the fire alarm to the monitoring terminal, realize remote monitoring and rapid response, and greatly improve the efficiency and reliability of fire safety management. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0030] Figure 1 It is a structural block diagram of an intelligent NB-IoT independent smoke fire detection alarm provided by an embodiment of the present disclosure;

[0031] Figure 2 It is a circuit diagram of an intelligent NB-IoT independent smoke fire detection alarm provided by an embodiment of the present disclosure;

[0032] Figure 3 This is a structural block diagram of another intelligent NB-IoT independent smoke fire detection alarm provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] In order to enable people in the technical field to better understand the present solution, the technical solution in the embodiment of the present solution will be clearly described below in conjunction with the drawings in the embodiment of the present solution. Obviously, the described embodiment is an embodiment of a part of the present solution, not all of the embodiments. Based on the embodiments in the present solution, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present solution.

[0034] The term "including" and any other variations in the specification and claims of this solution and the above drawings mean "including but not limited to", and is intended to cover non-exclusive inclusions and is not limited to the examples listed in the text. In addition, the terms "first" and "second" are used to distinguish different objects, not to describe a specific order.

[0035] With the continuous advancement of IoT technology, narrowband IoT (NB-IoT) technology has been widely used in the field of intelligent fire detection alarms due to its advantages of low power consumption, wide coverage, and large connections. NB-IoT technology provides reliable technical support for remote monitoring and real-time communication of fire detection alarms, making fire warning and response faster and more accurate.

[0036] Although NB-IoT technology has brought many advantages to smart fire detection alarms, it still faces some challenges in practical applications, especially the impact of ambient temperature changes on the performance of fire detection modules, which can easily lead to false alarms or missed alarms in fire detection alarms.

[0037] In order to solve the above problems, the embodiment of the present application provides an intelligent NB-IoT independent smoke fire detection alarm to solve the problem of false alarm or missed alarm of the existing fire detection alarm. The technical solution of the present application is described in detail below.

[0038] The following is a detailed description of the implementation of the present disclosure in conjunction with the specific drawings:

[0039] Figure 1 This is a schematic diagram of the structure of an intelligent NB-IoT independent smoke fire detection alarm provided by an embodiment of the present disclosure. Figure 1 The intelligent NB-IoT independent smoke fire detection alarm includes a fire sensor, a switch module, a first temperature compensation module, a signal amplification module, a second temperature compensation module, a main control unit and a remote communication module; the switch module is connected to the fire sensor, the switch module is used to power the fire sensor, and the fire sensor is used to detect fire; the first temperature compensation module is connected to the switch module, and the first temperature compensation module is used to perform temperature compensation for the switch module; the fire sensor is connected to the first end of the signal amplification circuit, the second end of the signal amplification circuit is connected to the main control unit, the second temperature compensation module is connected to the third end of the signal amplification module, and the second temperature compensation module performs temperature compensation for the fire sensor; the main control unit is connected to the monitoring terminal through the remote communication module.

[0040] In this embodiment, the fire sensor is responsible for sensing the change in smoke concentration, and the fire sensor can adopt the principle of photoelectric smoke sensing or ionization smoke sensing technology to detect the smoke concentration signal and convert it into a suitable electrical signal output. Once the smoke reaches a preset threshold, the fire sensor will send an electrical signal.

[0041] The switch module is used to provide working power for the fire sensor to ensure that the fire sensor can continuously and effectively detect the smoke condition in the environment. The switch module in this embodiment can be composed of transistor components such as triodes and MOS tubes. In order to ensure that a suitable working current can be provided, the static working point of the transistor should remain stable when it is working. However, since the thickness of the PN junction of the transistor and its junction capacitance change with the change of temperature, the static working point of the transistor will also change with the change of temperature (i.e., the working point drifts), and the current flowing through the fire sensor will also change, thereby affecting the accuracy of fire detection.

[0042] The first temperature compensation module performs temperature compensation for the switch module to reduce the impact of temperature on the switch module and ensure that the fire sensor can maintain the best working state at different temperatures.

[0043] Once the fire sensor detects the smoke signal, it will convert the signal into a suitable electrical signal output. However, the electrical signal output by the fire sensor is relatively weak and cannot be effectively recognized by the main control unit. Therefore, a signal amplification module is added between the fire sensor and the main control unit. The weak electrical signal output by the fire sensor passes through the signal amplification module. After receiving the signal, the signal amplification module will amplify it to a level that the main control unit can recognize. This can improve the signal-to-noise ratio of the signal, ensure that the main control unit can accurately identify the fire signal, and reduce misjudgment.

[0044] In this embodiment, the fire sensor is also affected by temperature. In practical applications, temperature changes will cause changes in the sensor output voltage, thereby affecting its detection accuracy and stability. Therefore, this embodiment also adds a second temperature compensation module, which is connected to the signal amplification module to perform temperature compensation on the electrical signal output by the fire sensor, eliminate the influence of ambient temperature changes on the judgment of smoke signal strength, and further improve the detection accuracy.

[0045] The main control unit is used to receive and process signals from sensors and determine whether a fire has occurred based on a preset algorithm. After receiving the amplified signal, the main control unit will quickly analyze and determine the fire situation. Based on NB-IoT technology, wireless communication with the monitoring terminal is achieved. Once the main control unit determines that a fire has occurred, the remote communication module immediately sends an alarm message to the monitoring center, the user's mobile phone or other designated terminals to achieve remote monitoring and instant alarm, speeding up the response.

[0046] It can be concluded from the above that by integrating a precise temperature compensation mechanism and an efficient signal amplification strategy, the fire detection accuracy and stability of this embodiment in complex environments are significantly enhanced. The use of the fire sensor in conjunction with the dual temperature compensation module (i.e., the first temperature compensation module and the second temperature compensation module) effectively solves the problem of false alarms and missed alarms caused by temperature changes, ensuring that the sensor can stably output reliable signals at different temperatures. The addition of the signal amplification module further enhances the signal processing capability, improves the accuracy of the main control unit in identifying fire signals, and reduces the impact of external interference. Combined with remote communication technology, this embodiment can instantly transmit fire alarms to the monitoring terminal, realize remote monitoring and rapid response, and greatly improve the efficiency and reliability of fire safety management.

[0047] like Figure 3 As shown, in one embodiment of the present disclosure, the intelligent NB-IoT independent smoke fire detection alarm also includes a signal filtering module; the first end of the signal filtering module is connected to the first end of the signal amplification module, and the second end of the signal filtering module is connected to the main control unit.

[0048] In this embodiment, the fire detector may be affected by various external factors such as electromagnetic interference and signal crosstalk, which may cause signal distortion and affect the judgment accuracy of the main control unit. By filtering out noise, the alarms caused by non-fire factors can be reduced, the accuracy of the alarm can be improved, and unnecessary panic or waste of resources caused by false alarms can be avoided. At the same time, it is ensured that there is no missed alarm in the event of a real fire and a timely response is given.

[0049] Therefore, in this embodiment, a signal filtering module is added between the signal amplification module and the main control unit. The signal filtering module can be a passive filter (such as an RC filter, an LC filter) or an active filter (such as a filtering circuit composed of an operational amplifier). Its working principle is to use the different response characteristics of circuit components (resistors, capacitors, inductors) to signals of different frequencies to filter signals. In this embodiment, the signal output by the signal amplification module first enters the signal filtering module, which allows low-frequency or specific frequency band signals related to fire alarms to pass through, while suppressing or weakening high-frequency noise and other irrelevant interference signals. The signal after filtering is purer and more stable, and is then transmitted to the main control unit for further analysis and judgment.

[0050] In this embodiment, noise and interference are one of the main reasons for the false alarm and missed alarm of the fire detector. The signal filtering module can effectively reduce such false alarm and missed alarm. By filtering out the noise and interference in the signal, the signal filtering module can ensure that the main control unit receives a clear and accurate fire signal, thereby improving the accuracy of fire detection.

[0051] like Figure 2 As shown, in one embodiment of the present disclosure, the switch module includes: a resistor R2, a capacitor C1, a transistor Q1, a resistor R1 and a variable resistor RP1; a first end of the resistor R2 is connected to a VCC power supply, a second end of the resistor R2 is connected to a base of the transistor Q1, and the base of the transistor Q1 is grounded through the resistor R1; a first end of the capacitor C1 is connected to the VCC power supply, and a second end of the capacitor C1 is connected to the base of the transistor Q1; a collector of the transistor Q1 is connected to a first end of the variable resistor RP1, a second end of the variable resistor RP1 is connected to the VCC power supply, an emitter of the transistor Q1 is connected to a power supply end of the fire sensor, a ground end of the fire sensor is grounded, and an output end of the fire sensor is connected to a first end of the signal amplification module.

[0052] In this embodiment, a specific implementation circuit of a switch module is disclosed:

[0053] When the circuit is powered on, the VCC power supply is added to the base of transistor Q1 through resistor R2, transistor Q1 is turned on, and the VCC power supply is added to the power supply end of the fire sensor through resistor RP1 and transistor Q1 in turn. Figure 2As shown, in this embodiment, the fire sensor can be represented by "U2". The first end of U2 represents the power supply end of the fire sensor, the second end of U2 represents the output end of the fire sensor, and the third end of U2 represents the ground end of the fire sensor. The current flowing through the fire sensor U2 can be adjusted by changing. Among them, the capacitor C1 is a filter capacitor to ensure that the electrical signal added to the transistor Q1 is more stable.

[0054] like Figure 2 As shown, in one embodiment of the present disclosure, the first temperature compensation module includes a diode D2; the anode of the diode D2 is connected to the second end of the resistor R2, and the cathode of the diode D2 is connected to the base of the transistor Q1.

[0055] In this embodiment, a specific implementation circuit of a first temperature compensation module is disclosed:

[0056] The first temperature compensation module is composed of diode D2. The on-state voltage of the diode is related to temperature. The temperature characteristics of the diode mainly include forward on-state voltage and reverse leakage current. The forward on-state voltage is usually about 0.7V (silicon material) at 25°C, and the on-state voltage will decrease slightly when the temperature rises.

[0057] In this embodiment, the base current of the transistor Q1 can be adjusted accordingly by the temperature characteristic of the diode D2. When the temperature rises, the forward conduction voltage of the diode D2 will decrease. Since the cathode of the diode is connected to the base of the transistor Q1, this voltage reduction will cause the voltage of the base of the transistor Q1 to decrease. According to the working principle of the transistor, the reduction of the base voltage may cause the collector current of the transistor Q1 to decrease, thereby adjusting the working state of the circuit to compensate for the influence of temperature. Conversely, when the temperature decreases, the forward conduction voltage of the diode D2 will increase, causing the voltage of the base of the transistor Q1 to increase, which may increase the collector current of the transistor Q1.

[0058] In this embodiment, the diode is a semiconductor device, and its current and voltage characteristics are closely related to temperature. The temperature characteristics of the diode can be directly used for temperature compensation without the need for additional complex circuits. Compared with other complex temperature compensation methods, using a diode for temperature compensation has lower costs.

[0059] like Figure 3 As shown, in one embodiment of the present disclosure, the intelligent NB-IoT independent smoke fire detection alarm also includes a constant current module; the constant current modules are respectively connected to the switch modules, and the constant current modules are used to provide a stable working current for the fire sensor.

[0060] In this embodiment, the first temperature compensation circuit can only perform temperature compensation on the transistor Q1 itself, and cannot compensate for the fluctuation of the VCC power supply. The performance of the fire sensor U2 is greatly affected by the power supply current, and current fluctuations may cause false alarms or reduce detection accuracy. For this reason, a constant current module is added in this embodiment.

[0061] The main function of the constant current module is to provide a stable current output to ensure that the fire sensor can maintain a constant working current after receiving power. In the switch module, the change of input voltage may cause the instability of the power supply current, and the constant current module can effectively solve this problem and provide a stable current environment for the fire sensor.

[0062] like Figure 2 As shown, in one embodiment of the present disclosure, the constant current module includes a transistor Q2, a resistor R8 and an optocoupler OC1; the base of the transistor Q2 is connected to the emitter of the transistor Q1, the collector of the transistor Q2 is grounded, the emitter of the transistor Q2 is connected to the first input end of the optocoupler OC1 through the resistor R8, the second input end of the optocoupler OC1 is connected to the VDD power supply, the first output end of the optocoupler OC1 is connected to the VCC power supply, and the second output end of the optocoupler OC1 is connected to the second end of the variable resistor RP1.

[0063] In this embodiment, a specific implementation circuit of a constant current module is disclosed:

[0064] The constant current module is mainly composed of transistor Q2, resistor R8 and optocoupler OC1, forming a closed-loop current control system. Specifically, the base of transistor Q2 is connected to the emitter of transistor Q1, forming an end connection between the front and rear circuits. When transistor Q1 is turned on, current will flow through its emitter, and this current is added to the base of transistor Q2, transistor Q2 is turned on, and transistor Q2 works in an amplified state. After transistor Q2 is turned on, the VDD power supply forms a loop after passing through the input end of optocoupler OC1, resistor R8 and transistor Q2 in sequence.

[0065] In this embodiment, a PNP transistor can be used as the transistor Q2. When the current output by the transistor Q1 increases, the base current of the transistor Q2 increases, and the collector current flowing through the transistor Q2 decreases. At the same time, the current flowing through the input end of the optocoupler OC1 decreases, and the output optical power of the light-emitting diode inside the optocoupler OC1 decreases. Therefore, the output end of the optocoupler OC1 can be equivalent to a photoresistor. When the optical power decreases, the resistance of the photoresistor increases, that is, the collector current flowing through the transistor Q1 decreases. Therefore, the emitter current of the transistor Q1 also decreases, which inhibits the emitter current of the transistor Q1 from increasing.

[0066] On the contrary, when the base current of transistor Q2 decreases, the output optical power of the light-emitting diode inside the optocoupler OC1 increases, the collector current flowing through the transistor Q1 increases, and the emitter current of the transistor Q1 also increases, which suppresses the decrease of the emitter current of the transistor Q1.

[0067] In this embodiment, the constant current module can provide a stable current supply for the fire sensor, ensuring that the fire sensor can maintain stable performance under various working conditions. At the same time, due to the use of optical couplers for isolation, the constant current module also has good electrical isolation performance, improving the safety and stability of the entire circuit.

[0068] like Figure 2 As shown, in one embodiment of the present disclosure, the signal amplification module includes a resistor R4, a capacitor C3, an amplifier U3, a resistor R5 and a resistor R6; the first end of the resistor R4 serves as the first end of the signal amplification module, the second end of the resistor R4 is grounded through the capacitor C3, the second end of the resistor R4 is connected to the in-phase input end of the amplifier U3, the inverting input end of the amplifier U3 is grounded through the resistor R5, the output end of the amplifier U3 is connected to the inverting input end of the amplifier U3 through the resistor R6, and the output end of the amplifier U3 is connected to the main control unit.

[0069] In this embodiment, a specific implementation circuit of a signal amplification module is disclosed:

[0070] The design of the signal amplifier module ensures the amplification and stable output of the input signal, providing accurate and reliable signal input for the main control unit.

[0071] The first end of the resistor R4 is used as the first end of the signal amplification module to receive the electrical signal output by the fire sensor U2. The second end of the resistor R4 is grounded through the capacitor C3 to form a simple RC circuit. The main function of the capacitor C3 is filtering, which can filter out high-frequency noise in the input signal and improve the purity of the signal. The second end of the resistor R4 is also connected to the non-inverting input of the amplifier U3. The amplifier U3 is responsible for amplifying the input signal. In order to ensure the stability and accuracy of the amplifier, its inverting input is grounded through a resistor R5 to form a negative feedback circuit. This negative feedback circuit can reduce the nonlinear distortion and temperature drift of the amplifier and improve the performance of the amplifier.

[0072] In this embodiment, the signal amplification module is designed to be concise and efficient, and the main control unit can receive more accurate and reliable signals, thereby improving the performance and reliability of the entire system.

[0073] like Figure 2As shown, in one embodiment of the present disclosure, the second temperature compensation module includes a resistor R11, a resistor R12, a resistor R13, a thermistor RT, an amplifier U4 and a resistor R10; the first end of the resistor R11 is connected to the VCC power supply, the second end of the resistor R11 is grounded through the resistor R13, the first end of the resistor R12 is connected to the VCC power supply, the second end of the resistor R12 is grounded through the thermistor RT, the second end of the resistor R11 is connected to the inverting input terminal of the amplifier U4, the second end of the resistor R12 is connected to the non-inverting input terminal of the amplifier U4, the output terminal of the amplifier U4 is connected to the inverting input terminal of the amplifier U4 through the resistor R10, the output terminal of the amplifier U4 is connected to the inverting input terminal of the amplifier U3, and the inverting input terminal of the amplifier U3 serves as the third end of the signal amplification module.

[0074] In this embodiment, a specific implementation circuit of a second temperature compensation module is disclosed:

[0075] like Figure 2 As shown, in this embodiment, the first ends of the resistors R11 and R12 are connected to the emitter of the transistor Q1, and share a power supply with the fire sensor U2, thereby ensuring the detection accuracy of the second temperature compensation module.

[0076] Resistors R11, R12, R13 and thermistor RT form a bridge for detecting an ambient temperature when the fire sensor is working. Assuming that at room temperature (25°C), the bridge is in a balanced state, that is, the voltage difference between the in-phase input terminal of amplifier U4 and the inverting input terminal of amplifier U4 is 0, so the output of amplifier U4 is 0. When the working temperature of fire sensor U2 changes, the resistance of thermistor RT changes, the bridge is unbalanced, and a voltage difference is generated between the in-phase input terminal of amplifier U4 and the inverting input terminal of amplifier U4. Amplifier U4 forms an amplifier circuit, which is amplified by amplifier U4 and sent to the inverting input terminal of amplifier U3. The output voltage of amplifier U4 is connected to the inverting input terminal of amplifier U3 (i.e., the third terminal of the signal amplification module) as a temperature compensation signal. In this way, when the ambient temperature changes, the signal can be temperature compensated by changing the voltage at the inverting input terminal of amplifier U3, thereby reducing the influence of temperature on the performance of fire sensor U2.

[0077] In this embodiment, the second temperature compensation module senses the change of ambient temperature through the thermistor RT, and uses the amplifier U4 to convert the temperature change into a voltage change, and finally adjusts the input of the amplifier U3 to achieve temperature compensation of the signal. This design helps to improve the stability and accuracy of the fire sensor U2 and the signal amplification module under different ambient temperatures.

[0078] like Figure 3As shown, in one embodiment of the present disclosure, the intelligent NB-IoT independent smoke fire detection alarm also includes an on-site alarm module; the on-site alarm module is connected to the main control unit.

[0079] In this embodiment, an on-site alarm module is also added. The on-site alarm module is directly connected to the main control unit. Once the main control unit determines that a fire has occurred, in addition to sending alarm information to the monitoring center or user terminal through the remote communication module, it can also immediately trigger an audible and visual alarm on site to quickly notify on-site personnel and achieve rapid evacuation and initial emergency response.

[0080] In the early stages of a fire, the rapid response of on-site personnel is crucial. The on-site alarm module can quickly attract the attention of surrounding personnel through sound and light alarms (such as high-decibel alarms and flashing LED lights). It can immediately warn even when network communication is temporarily interrupted, and is independent of external communication conditions. Especially at night or in environments with poor visibility, the visual prompts of the on-site alarm can effectively guide personnel to quickly find a safe exit, shorten evacuation time, and reduce casualties.

[0081] In this embodiment, the addition of the on-site alarm module strengthens the instant warning function of the intelligent NB-IoT independent smoke fire detection alarm, which not only meets the needs of safe evacuation of on-site personnel in emergency situations, but also is an important supplement to the integrity of the entire fire alarm system, ensuring more comprehensive fire safety protection.

[0082] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. An intelligent NB-IoT independent smoke fire detection alarm, characterized in that: It includes a fire sensor, a switch module, a first temperature compensation module, a signal amplification module, a second temperature compensation module, a main control unit and a remote communication module; The switch module is connected to the fire sensor, the switch module is used to supply power to the fire sensor, and the fire sensor is used to detect fire; The first temperature compensation module is connected to the switch module, and the first temperature compensation module is used to perform temperature compensation for the switch module; The fire sensor is connected to a first end of the signal amplifying circuit, a second end of the signal amplifying circuit is connected to the main control unit, the second temperature compensation module is connected to a third end of the signal amplifying module, and the second temperature compensation module performs temperature compensation for the fire sensor; The main control unit is connected to the monitoring terminal through a remote communication module; The switch module includes: a resistor R2, a capacitor C1, a transistor Q1, a resistor R1 and a variable resistor RP1; The first end of the resistor R2 is connected to the VCC power supply, the second end of the resistor R2 is connected to the base of the transistor Q1, and the base of the transistor Q1 is grounded through the resistor R1; The first end of the capacitor C1 is connected to the VCC power supply, and the second end of the capacitor C1 is connected to the base of the transistor Q1; The collector of the transistor Q1 is connected to the first end of the variable resistor RP1, the second end of the variable resistor RP1 is connected to the VCC power supply, the emitter of the transistor Q1 is connected to the power supply end of the fire sensor, the ground end of the fire sensor is grounded, and the output end of the fire sensor is connected to the first end of the signal amplification module; The first temperature compensation module includes a diode D2; The anode of the diode D2 is connected to the second end of the resistor R2, and the cathode of the diode D2 is connected to the base of the transistor Q1; It also includes a constant current module; The constant current modules are respectively connected to the switch modules, and the constant current modules are used to provide a stable working current for the fire sensor; The constant current module includes a transistor Q2, a resistor R8 and an optical coupler OC1; The base of the transistor Q2 is connected to the emitter of the transistor Q1, the collector of the transistor Q2 is grounded, the emitter of the transistor Q2 is connected to the first input end of the optocoupler OC1 through the resistor R8, the second input end of the optocoupler OC1 is connected to the VDD power supply, the first output end of the optocoupler OC1 is connected to the VCC power supply, and the second output end of the optocoupler OC1 is connected to the second end of the variable resistor RP1.

2. The intelligent NB-IoT independent smoke fire detection alarm according to claim 1, characterized in that: Also includes a signal filtering module; The first end of the signal filtering module is connected to the first end of the signal amplifying module, and the second end of the signal filtering module is connected to the main control unit.

3. The intelligent NB-IoT independent smoke fire detection alarm according to claim 1, characterized in that: The signal amplification module includes a resistor R4, a capacitor C3, an amplifier U3, a resistor R5 and a resistor R6; The first end of the resistor R4 serves as the first end of the signal amplification module, the second end of the resistor R4 is grounded through the capacitor C3, the second end of the resistor R4 is connected to the in-phase input end of the amplifier U3, the inverting input end of the amplifier U3 is grounded through the resistor R5, the output end of the amplifier U3 is connected to the inverting input end of the amplifier U3 through the resistor R6, and the output end of the amplifier U3 is connected to the main control unit.

4. The intelligent NB-IoT independent smoke fire detection alarm according to claim 3, characterized in that: The second temperature compensation module includes a resistor R11, a resistor R12, a resistor R13, a thermistor RT, an amplifier U4 and a resistor R10; The first end of the resistor R11 is connected to the VCC power supply, the second end of the resistor R11 is grounded through the resistor R13, the first end of the resistor R12 is connected to the VCC power supply, the second end of the resistor R12 is grounded through the thermistor RT, the second end of the resistor R11 is connected to the inverting input end of the amplifier U4, the second end of the resistor R12 is connected to the non-inverting input end of the amplifier U4, the output end of the amplifier U4 is connected to the inverting input end of the amplifier U4 through the resistor R10, the output end of the amplifier U4 is connected to the inverting input end of the amplifier U3, and the inverting input end of the amplifier U3 serves as the third end of the signal amplification module.

5. The intelligent NB-IoT independent smoke fire detection alarm according to claim 1, characterized in that: Also includes a field alarm module; The on-site alarm module is connected to the main control unit.

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