A fire detector battery current detection protection circuit, device and detection method

Abstract

The application discloses a kind of fire detector battery current detection protection circuit, device and detection method, circuit includes main control module, power supply module, first switch module, second switch module, voltage division module, fire detection module and wireless module;Main control module is used to successively send the voltage sampling signal of sampling fire detector battery;First switch module is used to switch on after successively obtaining voltage sampling signal;Second switch module is used to realize the sampling control of fire detector battery, voltage division module is used to obtain first sampling voltage, second sampling voltage and third sampling voltage in turn after the sampling voltage of fire detector battery is divided voltage;Main control module is used to realize the switch control of fire detector wireless function according to first sampling voltage, second sampling voltage and third sampling voltage.The present application can guarantee the reliable work of fire detector detection function, prolong the service life of internet of things fire detection equipment, low in cost, high reliability.

Description

Technical Field

[0001] This invention relates to the field of fire control technology, and in particular to a battery current detection and protection circuit, device and detection method for a fire detector. Background Technology

[0002] The Internet of Things (IoT) is a comprehensive technology that applies sensing, communication, and intelligent information processing to fire prevention. IoT technology offers advantages such as wide coverage, low power consumption, high connectivity, and low cost. However, when fire detection devices operate in environments with weak signals and strong interference, there is still significant room for improvement in the operational stability of fire detectors.

[0003] IoT detectors can be divided into two main functions: fire detection and wireless communication, with fire detection being the primary function and wireless communication as a secondary function. To ensure these two systems can operate independently, existing IoT detectors use separate power sources—two batteries—to guarantee that the detection function is not affected by insufficient power in the wireless function. For standalone products, using larger capacity batteries or increasing labor costs for later maintenance can effectively extend the device's lifespan. However, in today's market where cost-effectiveness is paramount, this also implies a lack of competitiveness.

[0004] Furthermore, the power supply capacity of stand-alone fire detectors can drop drastically after the batteries age. When the fire detection and wireless functions share the same power source, it is essential to ensure that the fire detection function is not affected by the wireless function throughout its lifespan, regardless of the device's operating status.

[0005] In fire detection equipment, high power consumption only occurs when the wireless function is active. If the instability caused by the wireless function in power monitoring can be eliminated, accurate battery level can be obtained effectively. However, the power consumption of wireless communication is neither fixed nor linear; it is inversely proportional to the current signal strength. Strong signal and low interference result in low power consumption, while weak signal and high interference result in high power consumption. Therefore, the large current during wireless packet transmission cannot be calculated using the load resistance. If the maximum power consumption of the wireless function is used as the load current for power detection, the power rating of the load resistor must be very high, leading to unnecessary additional losses during equipment use. Therefore, inventing a low-cost and highly reliable battery current detection and protection circuit for fire detectors is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of this application is to provide a battery current detection and protection circuit, device and detection method for a fire detector. In this solution, a single power supply is used to realize the functions of fire detection and wireless communication, thereby reducing equipment costs. It can accurately monitor the current power level of the fire detector battery. By accurately monitoring the current power level, the impact of wireless function on fire detection function in environments with poor signal is reduced.

[0007] To address the aforementioned technical problems, this application provides a battery current detection and protection circuit for a fire detector, comprising a main control module, a power supply module, a first switch module, a second switch module, a voltage divider module, a fire detection module, and a wireless module;

[0008] The main control module is electrically connected to the first switch module, the power supply module is electrically connected to the second switch module, the first switch module is electrically connected to the second switch module, and the voltage divider module is electrically connected to both the first switch module and the second switch module.

[0009] The main control module is electrically connected to the fire detection module and the wireless module respectively;

[0010] The main control module is used to sequentially send a first voltage sampling signal, a second voltage sampling signal, and a third voltage sampling signal to sample the fire detector battery; the first switch module is used to sequentially acquire the first voltage sampling signal, the second voltage sampling signal, and the third voltage sampling signal and then turn on; the second switch module is used to sequentially acquire the turn-on signal of the first switch module and then turn on, so as to realize the sampling control of the fire detector battery; the voltage divider module is used to divide the sampling voltage of the fire detector battery and then sequentially obtain the first sampling voltage, the second sampling voltage, and the third sampling voltage; wherein, the first sampling voltage is the fully charged sampling voltage of the fire detector battery, the second sampling voltage is the low-voltage sampling voltage of the fire detector battery after the wireless function is enabled, and the third sampling voltage is the current sampling voltage of the fire detector battery;

[0011] The main control module is used to determine the current battery level after the wireless function is activated and the periodically monitored current battery level based on the first sampling voltage, the second sampling voltage and the third sampling voltage;

[0012] The on / off control of the wireless function of the fire detector is achieved based on the current power value after the wireless function is activated and the current power value monitored periodically.

[0013] Preferably, the first switching module includes a first transistor, a first resistor, and a second resistor;

[0014] The base of the first transistor is electrically connected to the first end of the first resistor and the first end of the second resistor, respectively. The second end of the first resistor is electrically connected to the main control module, and the second end of the second resistor is electrically connected. The collector of the first transistor is grounded, and the emitter of the first transistor is electrically connected to the second switching module.

[0015] Preferably, the first switching module further includes a first capacitor;

[0016] The first terminal of the first capacitor is electrically connected to the base of the first transistor, and the second terminal of the first capacitor is grounded.

[0017] Preferably, the second switching module includes a second transistor, a third resistor, and a fourth resistor;

[0018] The collector of the second transistor is electrically connected to the power supply module and the first end of the third resistor, the second end of the third resistor is electrically connected to the base of the second transistor and the first end of the fourth resistor, and the second end of the fourth resistor is electrically connected to the first switch module.

[0019] Preferably, the voltage divider module includes a fifth resistor, a sixth resistor, and a seventh resistor;

[0020] The first end of the fifth resistor is electrically connected to the second switch module and the first end of the sixth resistor, the second end of the sixth resistor is electrically connected to the first end of the seventh resistor, the second end of the seventh resistor is grounded, and the second end of the fifth resistor is grounded.

[0021] To address the aforementioned technical problems, this application provides a battery current detection and protection device, including the aforementioned battery current detection and protection circuit for a fire detector.

[0022] To address the aforementioned technical problems, this application provides a battery current detection and protection method, applied to the aforementioned battery current detection and protection circuit of a fire detector, the protection method comprising:

[0023] The first voltage sampling signal, the second voltage sampling signal, and the third voltage sampling signal are sequentially sent to sample the battery of the fire detector.

[0024] The first switch module is turned on after sequentially acquiring the first voltage sampling signal, the second voltage sampling signal, and the third voltage sampling signal;

[0025] The second switch module is controlled to turn on after sequentially acquiring the on signal from the first switch module, so as to realize the sampling control of the fire detector battery;

[0026] The voltage divider module divides the sampling voltage of the fire detector battery to obtain the first sampling voltage, the second sampling voltage, and the third sampling voltage in sequence.

[0027] The current battery level after the wireless function is activated and the current battery level under periodic monitoring are determined based on the first sampling voltage, the second sampling voltage, and the third sampling voltage.

[0028] The on / off control of the wireless function of the fire detector is achieved based on the current power value after the wireless function is activated and the current power value monitored periodically.

[0029] Preferably, the step of controlling the on / off state of the fire detector's wireless function based on the current battery level after the wireless function is activated and the periodically monitored current battery level includes:

[0030] When the current battery level monitored periodically is lower than a preset battery threshold, the current battery level after the wireless function is activated is obtained.

[0031] The difference between the current battery level after the wireless function is activated and the current battery level monitored periodically is obtained.

[0032] If the difference is greater than a preset power threshold, the wireless function of the fire detector is turned off.

[0033] Preferably, obtaining the current battery level of the fire detector based on the first sampling voltage, the second sampling voltage, and the third sampling voltage includes:

[0034] Current battery level = (Third sampling voltage - Second sampling voltage) / (First sampling voltage - Second sampling voltage) * 100%.

[0035] Preferably, disabling the wireless function of the fire detector if the difference is greater than a preset power threshold includes:

[0036] If (current battery level value monitored periodically - current battery level value after wireless function activation) / current battery level value after wireless function activation * 100% > 30%;

[0037] Then the wireless function of the fire detector will be turned off.

[0038] The present invention discloses a fire detector battery current detection and protection circuit with the following beneficial effects. The fire detector battery current detection and protection circuit includes: a main control module, a power supply module, a first switch module, a second switch module, a voltage divider module, a fire detection module, and a wireless module. The main control module is used to sequentially send a first voltage sampling signal, a second voltage sampling signal, and a third voltage sampling signal to sample the fire detector battery. The first switch module is used to sequentially acquire the first voltage sampling signal, the second voltage sampling signal, and the third voltage sampling signal and then turn on. The second switch module is used to sequentially acquire the turn-on signal of the first switch module and then turn on, thereby realizing sampling control of the fire detector battery. The voltage divider module is used to divide the sampling voltage of the fire detector battery and sequentially obtain the first sampling voltage, the second sampling voltage, and the third sampling voltage. The first sampling voltage is the fully charged sampling voltage of the fire detector battery, the second sampling voltage is the low-voltage sampling voltage of the fire detector battery after the wireless function is enabled, and the third sampling voltage is the current sampling voltage of the fire detector battery. The main control module is used to control the switching of the wireless function of the fire detector based on the first sampling voltage, the second sampling voltage, and the third sampling voltage. Therefore, this invention can ensure the reliable operation of the fire detector's detection function, extend the service life of IoT fire detection equipment, and is low in cost and highly reliable. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic block diagram of a battery current detection and protection circuit for a fire detector according to a preferred embodiment of the present invention.

[0041] Figure 2 This is a circuit diagram of a battery current detection and protection circuit for a fire detector according to a preferred embodiment of the present invention.

[0042] Figure 3 This is a flowchart of a preferred embodiment of a fire detector battery current detection and protection method.

[0043] Figure 4 This is a flowchart of another fire detector battery current detection and protection method according to a preferred embodiment of the present invention. Detailed Implementation

[0044] The core of this application is to provide a fire detector battery current detection and protection circuit, device and detection method. In this solution, a single power supply is used to realize fire detection and wireless communication functions, reducing equipment costs; it can accurately monitor the current power of the fire detector battery, and by accurately monitoring the current power, the impact of wireless function on fire detection function in environments with poor signal is reduced.

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0046] Please see Figure 1 , Figure 1 The schematic diagram of a battery current detection and protection circuit for a fire detector provided in this application includes a main control module 1, a power supply module 2, a first switch module 3, a second switch module 4, a voltage divider module 5, a fire detection module 6, and a wireless module 7.

[0047] The main control module 1 is electrically connected to the first switch module 3, the power supply module 2 is electrically connected to the second switch module 4, the first switch module 3 is electrically connected to the second switch module 4, and the voltage divider module 5 is electrically connected to the first switch module 3 and the second switch module 4 respectively.

[0048] The main control module 1 is electrically connected to the fire detection module 6 and the wireless module 7 respectively;

[0049] The main control module 1 is used to sequentially send a first voltage sampling signal, a second voltage sampling signal, and a third voltage sampling signal to sample the fire detector battery; the first switch module 3 is used to sequentially acquire the first voltage sampling signal, the second voltage sampling signal, and the third voltage sampling signal and then turn on; the second switch module 4 is used to sequentially acquire the turn-on signal of the first switch module 3 and then turn on, so as to realize the sampling control of the fire detector battery; the voltage divider module 5 is used to divide the sampling voltage of the fire detector battery and then sequentially obtain the first sampling voltage, the second sampling voltage, and the third sampling voltage; wherein, the first sampling voltage is the fully charged sampling voltage of the fire detector battery, the second sampling voltage is the low-voltage sampling voltage of the fire detector battery, and the third sampling voltage is the current sampling voltage of the fire detector battery;

[0050] The main control module 1 is used to determine the current battery level after the wireless function is activated and the current battery level under periodic monitoring based on the first sampling voltage, the second sampling voltage and the third sampling voltage;

[0051] The on / off control of the wireless function of the fire detector is achieved based on the current power value after the wireless function is activated and the current power value monitored periodically.

[0052] In existing technologies, IoT detectors use two batteries to power their devices, ensuring that the wireless function is not affected by insufficient power. For standalone products, using larger capacity batteries or increasing labor costs for later maintenance can effectively extend the device's lifespan. However, in today's market where cost-effectiveness is paramount, this also implies a lack of competitiveness.

[0053] To address the aforementioned shortcomings, this application utilizes the cooperation of the main control module 1, power supply module 2, first switch module 3, second switch module 4, voltage divider module 5, fire detection module 6, and wireless module 7 to ensure the reliable operation of the fire detector's detection function and extend the service life of the IoT fire detection equipment.

[0054] Specifically, in this embodiment, the fire detector only experiences high power consumption when its wireless function is activated. This means that if the instability caused by the wireless function affecting power monitoring can be eliminated, the accurate battery level of the fire detector can be obtained effectively. However, the relationship between wireless communication functionality and power consumption is not fixed or linear. Generally, wireless communication functionality is inversely proportional to the current signal strength; that is, high signal strength and low interference result in low power consumption, while low signal strength and high interference result in high power consumption.

[0055] Specifically, in this embodiment, after acquiring the first sampling voltage, the second sampling voltage, and the third sampling voltage, the power value after the wireless function is enabled and the periodically monitored power value are determined by the first sampling voltage, the second sampling voltage, and the third sampling voltage. Based on the current power value after the wireless function is activated and the current power value of the periodically monitored power value, the on / off control of the wireless function of the fire detector is realized.

[0056] Specifically, in the initial stage of use, fire detectors with IoT functionality have relatively sufficient battery power, and low signal strength has little impact on battery wear. Therefore, in the initial stage of use, monitoring the fire detector's battery power does not need to take wireless communication into account. In this embodiment, when the fire detector's wireless function is turned off, it is in a light-load state. Monitoring the current battery power value under light load can obtain periodic monitoring results. After the fire detector with IoT functionality has been used for a period of time, i.e., when the battery power drops to a preset battery power threshold, the low-voltage sampling function is enabled after each wireless function activation to record the current battery power value after the wireless function activation.

[0057] In summary, this application provides a fire detector battery current detection and protection circuit. This circuit includes a main control module 1, a power supply module 2, a first switch module 3, a second switch module 4, a voltage divider module 5, a fire detection module 6, and a wireless module 7. The main control module 1 sequentially sends a first voltage sampling signal, a second voltage sampling signal, and a third voltage sampling signal to sample the fire detector battery. The first switch module 3 sequentially acquires the first, second, and third voltage sampling signals and then turns on. The second switch module 4 sequentially acquires the on signal from the first switch module 3 and then turns on, thereby achieving sampling control of the fire detector battery. The voltage divider module 5 is used to divide the sampling voltage of the fire detector battery to obtain a first sampling voltage, a second sampling voltage, and a third sampling voltage in sequence. The first sampling voltage is the fully charged sampling voltage of the fire detector battery, the second sampling voltage is the low-voltage sampling voltage of the fire detector battery, and the third sampling voltage is the current sampling voltage of the fire detector battery. The main control module 1 is used to determine the current battery level after the wireless function is activated and the periodically monitored current battery level based on the first, second, and third sampling voltages. Based on the current battery level after the wireless function is activated and the periodically monitored current battery level, the main control module 1 controls the on / off switching of the fire detector's wireless function. Therefore, this invention ensures the reliable operation of the fire detector's detection function, extends the service life of IoT fire detection equipment, and is low in cost and highly reliable.

[0058] Based on the above embodiments:

[0059] Please refer to Figure 2 , Figure 2 The circuit diagram provided in this application is a battery current detection and protection circuit for a fire detector.

[0060] In a preferred embodiment, the first switching module 3 includes a first transistor Q3, a first resistor R9, and a second resistor R14;

[0061] The base of the first transistor Q3 is electrically connected to the first end of the first resistor R9 and the first end of the second resistor R14. The second end of the first resistor R9 is electrically connected to the main control module 1. The second end of the second resistor R14 is electrically connected. The collector of the first transistor Q3 is grounded. The emitter of the first transistor Q3 is electrically connected to the second switch module 4.

[0062] In a preferred embodiment, the first switch module 3 further includes a first capacitor C22;

[0063] The first terminal of the first capacitor C22 is electrically connected to the base of the first transistor Q3, and the second terminal of the first capacitor C22 is grounded.

[0064] In a preferred embodiment, the second switch module 4 includes a second transistor Q2, a third resistor R1, and a fourth resistor R7;

[0065] The collector of the second transistor Q2 is electrically connected to the power supply module 2 and the first end of the third resistor R1, respectively. The second end of the third resistor R1 is electrically connected to the base of the second transistor Q2 and the first end of the fourth resistor R7, respectively. The second end of the fourth resistor R7 is electrically connected to the first switch module 3.

[0066] In a preferred embodiment, the voltage divider module 5 includes a fifth resistor R8, a sixth resistor R10, and a seventh resistor R15;

[0067] The first end of the fifth resistor R8 is electrically connected to the first end of the second switch module 4 and the sixth resistor R10, respectively. The second end of the sixth resistor R10 is electrically connected to the first end of the seventh resistor R15. The second end of the seventh resistor R15 is grounded, and the second end of the fifth resistor R8 is grounded.

[0068] Specifically, in this embodiment, during operation, the fire detector device samples the battery voltage of the power supply module 2. The main control module 1 enables the base of the first transistor Q3 and outputs a high level through the CS pin, thereby turning on the first transistor Q3 and the second transistor Q2. VDD is directly connected to the positive terminal of the battery. The current voltage ADC sampling value is obtained by voltage division through the fifth resistor R8, the sixth resistor R10 and the seventh resistor R15 in the voltage divider module 5.

[0069] This application also provides a battery current detection and protection device, including a battery current detection and protection circuit for a fire detector.

[0070] Please see Figure 3 , Figure 3 This is a flowchart illustrating a method for detecting and protecting the battery current of a fire detector, as provided in this application.

[0071] This application also provides a battery current detection and protection method, applied to a battery current detection and protection circuit of a fire detector, the protection method including:

[0072] S1. Sequentially send the first voltage sampling signal, the second voltage sampling signal, and the third voltage sampling signal to sample the fire detector battery;

[0073] S2. After the first switch module 3 acquires the first voltage sampling signal, the second voltage sampling signal and the third voltage sampling signal in sequence, it is turned on.

[0074] S3. The second switch module 4 is used to sequentially obtain the conduction signal of the first switch module 3 and then conduct to realize the sampling control of the fire detector battery.

[0075] S4. The control voltage divider module 5 divides the sampling voltage of the fire detector battery to obtain the first sampling voltage, the second sampling voltage and the third sampling voltage in sequence.

[0076] S5. Determine the current battery level after the wireless function is activated and the current battery level monitored periodically based on the first sampling voltage, the second sampling voltage and the third sampling voltage.

[0077] S6. Based on the current power value after the wireless function is activated and the current power value monitored periodically, the on / off control of the wireless function of the fire detector is realized.

[0078] Please see Figure 4 , Figure 4 A flowchart illustrating another fire detector battery current detection and protection method provided in this application.

[0079] As a preferred embodiment, controlling the on / off state of the fire detector's wireless function based on the current battery level after the wireless function is activated and the periodically monitored current battery level includes:

[0080] S61. When the current battery level monitored periodically is lower than the preset battery threshold, obtain the current battery level after the wireless function is activated.

[0081] S62. Obtain the difference between the current battery level after the wireless function is activated and the current battery level monitored periodically;

[0082] S63. If the difference is greater than the preset power threshold, the wireless function of the fire detector will be turned off.

[0083] In a preferred embodiment, obtaining the current battery level of the fire detector based on the first sampling voltage, the second sampling voltage, and the third sampling voltage includes:

[0084] Current battery level = (Third sampling voltage - Second sampling voltage) / (First sampling voltage - Second sampling voltage) * 100%.

[0085] In a preferred embodiment, if the difference is greater than a preset power threshold, disabling the wireless function of the fire detector includes:

[0086] If (current battery level monitored periodically - current battery level after wireless function activation) / current battery level after wireless function activation * 100% > 30%;

[0087] Then disable the wireless function of the fire detector.

[0088] Specifically, in this embodiment, the current battery level is obtained by sampling the voltage ADC value when the battery is fully charged and the voltage ADC value when the battery is low, that is, the current battery level = (third sampling voltage - second sampling voltage) / (first sampling voltage - second sampling voltage) * 100%.

[0089] Specifically, in this embodiment, the initial battery level when the wireless sampling function is activated is set to 50%. Since the fire detector device has been running for a short time, the battery level is relatively sufficient, and the high current operation has little impact on the voltage. That is, when the current battery level is below 50%, after each wireless function operation, the MCU synchronously outputs a high level to CS to enable the voltage sampling function, thereby obtaining the battery level sampled after each wireless operation.

[0090] Specifically, as the fire detection equipment is used for longer periods of time, the battery level decreases, and the difference between the current battery level after the wireless function is activated and the current battery level monitored periodically increases. This invention needs to ensure that the current battery level monitored periodically is greater than the current battery level after the wireless function is activated. Otherwise, it is determined that the current battery level is insufficient to support the normal operation of the equipment under poor signal conditions. In order to ensure the fire detection function, the wireless function needs to be turned off.

[0091] Specifically, in this embodiment, a battery drop protection line can also be set, initially set to 30%, i.e., (current battery value monitored periodically - current battery value after wireless function activation) / current battery value after wireless function activation * 100% > 30%. If this value is greater than 30%, it is determined that the current battery level is insufficient for normal device operation under poor signal conditions, and the wireless function is disabled. The wireless function is reactivated when a new battery is replaced or when the periodic sampling value rebounds to above 50%.

[0092] Once the system determines that the wireless function needs to be turned off, the MCU will disable the wireless function via AT commands, thereby ensuring that the fire detection function can be used normally.

[0093] For a description of the battery current detection and protection circuit for a fire detector provided in this application, please refer to the above embodiments; further details will not be repeated here.

[0094] It should be noted that, in this specification, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0095] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery current detection and protection circuit for a fire detector, characterized in that, It includes a main control module, a power supply module, a first switch module, a second switch module, a voltage divider module, a fire detection module, and a wireless module; The main control module is electrically connected to the first switch module, the power supply module is electrically connected to the second switch module, the first switch module is electrically connected to the second switch module, and the voltage divider module is electrically connected to both the first switch module and the second switch module. The main control module is electrically connected to the fire detection module and the wireless module respectively; The main control module is used to sequentially send a first voltage sampling signal, a second voltage sampling signal, and a third voltage sampling signal to sample the fire detector battery; the first switch module is used to sequentially acquire the first voltage sampling signal, the second voltage sampling signal, and the third voltage sampling signal and then turn on; the second switch module is used to sequentially acquire the turn-on signal of the first switch module and then turn on, so as to realize the sampling control of the fire detector battery; the voltage divider module is used to divide the sampling voltage of the fire detector battery and then sequentially obtain the first sampling voltage, the second sampling voltage, and the third sampling voltage; wherein, the first sampling voltage is the fully charged sampling voltage of the fire detector battery, the second sampling voltage is the low-voltage sampling voltage of the fire detector battery after the wireless function is enabled, and the third sampling voltage is the current sampling voltage of the fire detector battery; The main control module is used to determine the current battery level after the wireless function is activated and the periodically monitored current battery level based on the first sampling voltage, the second sampling voltage and the third sampling voltage; The on / off control of the wireless function of the fire detector is achieved based on the current power value after the wireless function is activated and the current power value monitored periodically. Controlling the on / off state of the fire detector's wireless function based on the current battery level after the wireless function is activated and the periodically monitored current battery level includes: When the current battery level monitored periodically is lower than a preset battery threshold, the current battery level after the wireless function is activated is obtained. The difference between the current battery level after the wireless function is activated and the current battery level monitored periodically is obtained. If the difference is greater than a preset power threshold, the wireless function of the fire detector is turned off. The current battery level of the fire detector is obtained based on the first sampling voltage, the second sampling voltage, and the third sampling voltage, including: Current battery level = (Third sampling voltage - Second sampling voltage) / (First sampling voltage - Second sampling voltage) 100%; If the difference is greater than a preset power threshold, disabling the wireless function of the fire detector includes: If (current battery level monitored periodically - current battery level after wireless function activation) / current battery level after wireless function activation 100% > 30%; Then the wireless function of the fire detector will be turned off.

2. The battery current detection and protection circuit for a fire detector according to claim 1, characterized in that, The first switching module includes a first transistor, a first resistor, and a second resistor; The base of the first transistor is electrically connected to the first end of the first resistor and the first end of the second resistor, respectively. The second end of the first resistor is electrically connected to the main control module, and the second end of the second resistor is electrically connected. The collector of the first transistor is grounded, and the emitter of the first transistor is electrically connected to the second switching module.

3. The fire detector battery current detection and protection circuit according to claim 2, characterized in that, The first switching module also includes a first capacitor; The first terminal of the first capacitor is electrically connected to the base of the first transistor, and the second terminal of the first capacitor is grounded.

4. The battery current detection and protection circuit for a fire detector according to claim 1, characterized in that, The second switching module includes a second transistor, a third resistor, and a fourth resistor; The collector of the second transistor is electrically connected to the power supply module and the first end of the third resistor, the second end of the third resistor is electrically connected to the base of the second transistor and the first end of the fourth resistor, and the second end of the fourth resistor is electrically connected to the first switch module.

5. The fire detector battery current detection and protection circuit according to claim 1, characterized in that, The voltage divider module includes a fifth resistor, a sixth resistor, and a seventh resistor; The first end of the fifth resistor is electrically connected to the second switch module and the first end of the sixth resistor, the second end of the sixth resistor is electrically connected to the first end of the seventh resistor, the second end of the seventh resistor is grounded, and the second end of the fifth resistor is grounded.

6. A battery current detection and protection device, characterized in that, The invention includes a battery current detection and protection circuit for a fire detector as described in any one of claims 1 to 5.

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