Passive low-power-consumption temperature sensor and temperature acquisition system

Abstract

The invention provides a passive low-power-consumption temperature sensor and a temperature acquisition system, and relates to the technical field of temperature detection. Comprising a radio frequency front end, an analog front end, a processing module, a sensing module and a memory, the radio frequency front end is respectively connected with the analog front end, the processing module and the sensing module, and the processing module is also respectively connected with the analog front end, the sensing module and the memory; the radio frequency front end is used for receiving energy of a relay transmitting signal and data in a carrier wave; the analog front end is used for providing an enable signal for the processing module; the processing module is used for processing the sampling signal of the sensor module and sending the processed sampling signal to the repeater through the radio frequency front end; wherein the sensing module comprises an interdigital capacitor, the surface of the interdigital capacitor is coated with a silicone oil layer, and the dielectric constant of the silicone oil layer changes along with the change of the temperature. The passive low-power-consumption temperature sensor and the temperature acquisition system provided by the invention have the advantages that a power supply does not need to be replaced, and the workload of workers is reduced.

Description

Technical Field

[0001] The present application relates to the field of temperature detection technology, and in particular to a passive low-power temperature sensor and a temperature acquisition system. Background Art

[0002] At present, the temperature measurement of underground cables is of great significance. By measuring the surface temperature of the cable, the cable core temperature can be determined by inversion. Therefore, the performance of the cable core laid on the cable surface is crucial.

[0003] Since the downhole cables are buried underground, it is inconvenient to replace the power supply of the active temperature sensor, resulting in a heavy workload for the staff. Summary of the invention

[0004] The purpose of the present application is to provide a passive low-power temperature sensor and a temperature acquisition system to solve the problem of inconvenient power supply replacement of active temperature sensors in the prior art.

[0005] In order to achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0006] On the one hand, an embodiment of the present application provides a passive low-power temperature sensor, which is applied to a temperature acquisition system, wherein the temperature acquisition system also includes a repeater, and the passive low-power temperature sensor is used to be installed on a cable and communicate with the repeater; the passive low-power temperature sensor includes a radio frequency front end, an analog front end, a processing module, a sensor module and a memory, wherein the radio frequency front end is respectively connected to the analog front end, the processing module and the sensor module, and the processing module is also respectively connected to the analog front end, the sensor module and the memory;

[0007] The radio frequency front end is used to receive the energy of the signal transmitted by the repeater and the data in the carrier;

[0008] The analog front end is used to provide an enable signal for the processing module;

[0009] The processing module is used to process the sampling signal of the sensor module and send the processed sampling signal to the repeater through the RF front end; wherein,

[0010] The sensing module includes an interdigital capacitor, the surface of the interdigital capacitor is coated with a silicone oil layer, and the dielectric constant of the silicone oil layer changes with temperature.

[0011] Optionally, the processing module is further configured to obtain a predicted power consumption value of the sensor according to the current temperature value when the current temperature value is greater than a threshold value;

[0012] When the predicted power consumption value is greater than a preset value, reducing the sampling rate of the passive low power consumption temperature sensor;

[0013] When the predicted power consumption value is less than a preset value, the sampling rate of the passive low power consumption temperature sensor is maintained.

[0014] Optionally, the sensor predicts the power consumption value to satisfy the formula:

[0015] P=β0+β1×T

[0016] Among them, P represents the power consumption value predicted by the sensor, β0 represents the basic power consumption value when the temperature is 0, β1 represents the change of power consumption with temperature, and T represents the current temperature.

[0017] Optionally, the passive low-power temperature sensor further comprises an arc-shaped housing, the sensing module is arranged at the center of the arc-shaped housing, four corners of the arc-shaped housing are respectively connected to four first connecting members, and the centers of two sides of the arc-shaped housing are connected to two second connecting members;

[0018] When the passive low-power temperature sensor is installed on the cable, the four first connectors are connected in an X shape, the two second connectors are connected, and the connection points of the first connectors and the second connectors coincide and are opposite to the center position of the arc-shaped housing.

[0019] Optionally, the sensing module includes a constant current source, a sensing unit, a preamplifier, a zero point adjustment unit, a signal amplifier and a range adjustment unit. The constant current source, the sensing unit, the preamplifier and the signal amplifier are connected in sequence, the preamplifier is connected to the zero point adjustment unit, and the signal amplifier is connected to the range adjustment unit.

[0020] Optionally, the sensor unit includes a finger capacitor, a Schmitt trigger, and a resistor, one end of the finger capacitor is grounded, and the other end is respectively connected to the input end of the Schmitt trigger and one end of the resistor, the output end of the Schmitt trigger is connected to the other end of the resistor, and the output end of the Schmitt trigger is connected to the preamplifier.

[0021] On the other hand, an embodiment of the present application further provides a temperature acquisition system, the temperature acquisition system comprising a repeater and the above-mentioned passive low-power temperature sensor, the passive low-power temperature sensor being communicatively connected to the repeater;

[0022] The repeater is used to adjust the carrier transmission power according to the current temperature after obtaining the current temperature value if the current temperature value is greater than a threshold value.

[0023] Optionally, the adjusted carrier transmission power satisfies the formula:

[0024]

[0025] Among them, P1 represents the carrier transmission power after adjustment, P0 represents the carrier transmission power before adjustment, T1 represents the current temperature value, T2 represents the average temperature in the past preset time period, m represents the temperature influence factor, and the temperature influence factor is 0.5~1.

[0026] Optionally, the repeater includes a first repeater and a second repeater, the first repeater and the second repeater are both communicatively connected to the passive low-power temperature sensor, and the first repeater and the second repeater are arranged at different positions;

[0027] When the first repeater is working, the second repeater is in sleep mode;

[0028] When the first repeater fails, the second repeater works.

[0029] Optionally, the carrier transmission power of the second repeater when working satisfies the formula:

[0030]

[0031] Among them, P2 represents the carrier transmission power when the second repeater is working, P3 represents the carrier transmission power when the first repeater is working, T1 represents the current temperature value, T2 represents the temperature average value of the past preset time period, m represents the temperature influence factor, and the temperature influence factor is 0.5~1; d1 represents the distance between the second repeater and the passive low power consumption temperature sensor, d2 represents the distance between the first repeater and the passive low power consumption temperature sensor, n represents the distance influence factor, and the distance influence factor is 1.5~2.

[0032] Compared with the prior art, this application has the following beneficial effects:

[0033] The present application provides a passive low-power temperature sensor and a temperature acquisition system, which are applied to a temperature acquisition system. The temperature acquisition system also includes a repeater. The passive low-power temperature sensor is used to be installed on a cable and communicate with the repeater. The passive low-power temperature sensor includes a radio frequency front end, an analog front end, a processing module, a sensor module and a memory. The radio frequency front end is connected to the analog front end, the processing module and the sensor module respectively, and the processing module is also connected to the analog front end, the sensor module and the memory respectively. The radio frequency front end is used to receive the energy of the signal transmitted by the repeater and the data in the carrier. The analog front end is used to provide an enable signal to the processing module. The processing module is used to process the sampling signal of the sensor module and send the processed sampling signal to the repeater through the radio frequency front end. The sensor module includes a finger capacitor, and the surface of the finger capacitor is coated with a silicone oil layer. The dielectric constant of the silicone oil layer changes with temperature. Since the present application uses a passive low-power temperature sensor to measure the temperature, there is no need to replace the power supply of the sensor, which reduces the workload of the staff.

[0034] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A schematic diagram of a module of a passive low-power temperature sensor provided in an embodiment of the present application.

[0037] Figure 2 A schematic diagram of a sensor module according to an embodiment of the present application.

[0038] Figure 3 A circuit diagram of a sensor unit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0041] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0042] It should be noted that, in this document, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0043] See also Figure 1 The embodiment of the present application provides a passive low-power temperature sensor, which is applied to a temperature acquisition system. The temperature acquisition system also includes a repeater. The passive low-power temperature sensor is used to be installed on a cable and communicate with the repeater; the passive low-power temperature sensor includes a radio frequency front end, an analog front end, a processing module, a sensor module and a memory. The radio frequency front end is respectively connected to the analog front end, the processing module and the sensor module, and the processing module is also respectively connected to the analog front end, the sensor module and the memory; the radio frequency front end is used to receive the energy of the signal transmitted by the repeater and the data in the carrier; the analog front end is used to provide an enable signal to the processing module; the processing module is used to process the sampling signal of the sensor module, and send the processed sampling signal to the repeater through the radio frequency front end; wherein, the sensor module includes a finger capacitor, the surface of the finger capacitor is coated with a silicone oil layer, and the dielectric constant of the silicone oil layer changes with temperature.

[0044] By providing a passive low-power temperature sensor, it is possible to eliminate the need to provide a power supply on the temperature sensor, thereby reducing the size of the temperature sensor and the workload of the staff.

[0045] Among them, passive low-power temperature sensors can be realized by integrating wireless RFID (Radio Frequency Identification) and micro-power MEMS (Micro-Electro-Mechanical System) sensor technology.

[0046] In practical applications, the following technical difficulties need to be solved:

[0047] 1. Micro-power consumption processing mechanism: The terminal sensing device is completed without external power supply during the entire working process. For power consumption considerations during working, the electromagnetic wave is sent in a timed short-time pulse form.

[0048] 2. High protection level: According to the application scenario, the equipment is installed in the underground of the pipe gallery. The working environment is not ideal. Moisture, water immersion, corrosion and other conditions are inevitable. Therefore, the protection level must be above IP68 to meet the actual use requirements.

[0049] 3. Temperature measurement accuracy: Since the equipment needs to perform real-time online safety monitoring of operating cables, the monitoring accuracy and sensitivity must be high enough, and the design accuracy is required to reach ±1°C.

[0050] 4. The contradiction between miniaturized design and long-distance communication: Because the device is installed on underground cables during use, and based on cost considerations, the overall design structure cannot be too large, otherwise it will be inconvenient to install. At the same time, the small appearance structure limits the size of the embedded antenna design, and on this basis, a longer wireless communication distance (more than 5 meters) must be obtained.

[0051] In order to solve the above problems, this application is implemented in the following ways:

[0052] The entire passive low power temperature sensor consists of 2 parts:

[0053] 1. The long-distance passive RFID tag part uses ultra-high frequency (UHF RFID).

[0054] 2. MEMS micro power consumption sensor part.

[0055] Through the integration of technologies, a whole is formed. It not only has the wireless data interaction, data storage, identity identification and other functions of the RFID tag, but also has the function of providing driving for the MEMS sensor. The data sensed by the sensor can be stored in the RFID built-in memory, and after being integrated with the RFID data itself, wireless data interaction can be realized through the reader device.

[0056] On this basis, please continue to refer to Figure 1The passive low-power temperature sensor consists of a sensor module, a radio frequency front end, an analog front end, a processing module, and a memory. The function of the sensor module is to realize temperature detection and digital processing, including a sampling and holding circuit, a comparator, a SAR logic, and a digital-to-analog converter (DAC), a temperature sensitive circuit (Sensor), a voltage reference circuit, and a bias circuit. The first four circuits constitute the SARADC; the function of the radio frequency front end is to collect, receive, and send signal energy, including a rectifier circuit, a modulator, and a demodulator; the analog front end function provides the system with a stable DC voltage, clock, and reset signal; the processing module can be a digital baseband processor, which can process the received signal. The memory is used to store user information and system initialization information.

[0057] Since passive electronic tags have no energy supply, they need to obtain energy from the radio frequency waves emitted by the reader to work. Therefore, in order to obtain a tag chip with a long working distance, the power consumption of the chip itself must be low enough. Excessive power consumption of the circuit will reduce the effective working distance of the tag, thereby weakening the application advantages of UHF RFID. In order to achieve a readable distance of more than 5 meters, the entire power consumption of the system must be within 20uW. Start from the following aspects to study low power consumption solutions and achieve low system power consumption.

[0058] (1) High-efficiency rectifier technology

[0059] The rectifier converts the RF signal energy sent by the reader into a DC voltage that can be used for circuit operation. Its efficiency directly determines the system operating distance.

[0060] (2) Gated clock technology

[0061] The combination of global gating and local gating can effectively reduce the system's dynamic power consumption, saving about 20% to 60% of the power consumption.

[0062] (3) Ultra-low power (nanowatt level) high-precision analog-to-digital conversion circuit (ADC) technology

[0063] The function of ADC is to convert analog signals into digital signals that can be sent by the RFID tag system. ADC is the main part of the power consumption in the entire temperature sensor. Its accuracy and power consumption will affect the accuracy and power consumption of the system. Based on low-power design considerations, this solution intends to use a SARADC structure suitable for low-speed, low-power applications in the temperature sensor part. In order to further reduce power consumption, the DAC in the SARADC adopts a charge redistribution type. In terms of accuracy, the accuracy of the analog-to-digital converter can be adjusted based on the DAC capacitor mismatch and parasitics, and the kickback noise of the comparator.

[0064] In order to make the chip meet the accuracy requirements, the temperature sensing circuit is the core of the temperature sensor, which is based on the ultra-low power consumption (nanowatt level) temperature sensitive circuit linearization technology of the CMOS process. Its function is to convert the temperature parameter into an electrical parameter (voltage, current or frequency) that can be detected by the circuit. In the CMOS process, the threshold voltage of the MOS tube and the turn-on voltage of the diode are usually used as temperature sensitive elements. Compared with the threshold voltage of the MOS device, the turn-on voltage of the diode has certain advantages in terms of process stability and temperature-related linearity, so diodes are more widely used in most applications.

[0065] In terms of hardware implementation, the RF front-end circuit uses a full-wave bridge rectifier circuit with high rectification efficiency to rectify the carrier coupled to the inductor, and then uses the linear regulator TPS71550 with fast response speed, small output ripple, simple circuit, and continuously adjustable output to output a 5V DC voltage to power the secondary system circuit. In the load modulation circuit, the MOS tube uses the IRF540 switch tube with a faster switching speed to control its on and off using the frequency signal of the sensor. The on-resistance of IRF540+ is extremely small, only about 0.07 ohms. When the on-off conversion is performed, the impedance at both ends of the inductor also changes, causing the amplitude of the carrier reflected back to the main system to change, that is, the load modulation is completed.

[0066] For the sensor module, the sensor module includes a constant current source, a sensor unit, a preamplifier, a zero point adjustment unit, a signal amplifier and a range adjustment unit. The constant current source, the sensor unit, the preamplifier and the signal amplifier are connected in sequence, the preamplifier is connected to the zero point adjustment unit, and the signal amplifier is connected to the range adjustment unit.

[0067] Furthermore, the passive low-power temperature sensor provided in the present application is a capacitive sensor, which has the advantages of low power consumption, high reliability and convenient implementation.

[0068] In addition, the passive low-power temperature sensor is made of a high aspect ratio, based on a glass substrate interdigital capacitor. A layer of silicone oil is evenly coated on the surface of the capacitor. Since silicone oil is sensitive to temperature, when the temperature changes, the dielectric constant of the silicone oil changes, causing the capacitance to change.

[0069] On this basis, the sensor unit includes a cross-finger capacitor, a Schmitt trigger, and a resistor. One end of the cross-finger capacitor is grounded, and the other end is respectively connected to the input end of the Schmitt trigger and one end of the resistor. The output end of the Schmitt trigger is connected to the other end of the resistor, and the output end of the Schmitt trigger is connected to the preamplifier.

[0070] Through this setting method, the capacitance value of the sensor can be converted into a frequency signal. On the one hand, the frequency signal is less affected by external interference and has good robustness; on the other hand, it is more convenient to implement using a relaxation oscillator.

[0071] In order to further improve the performance of the passive low-power temperature sensor, the processing module is also used to obtain the sensor predicted power consumption value according to the current temperature value when the current temperature value is greater than the threshold value;

[0072] When the predicted power consumption value is greater than the preset value, the sampling rate of the passive low power consumption temperature sensor is reduced; when the predicted power consumption value is less than the preset value, the sampling rate of the passive low power consumption temperature sensor is maintained.

[0073] The applicant has found that there is a certain relationship between the power consumption and temperature of a passive low-power temperature sensor. When the detected temperature is high, the power consumption is relatively high. When the temperature is higher than the threshold, the sensor sampling value may be unstable. In view of this, the present application can achieve control of the sampling rate by predicting the sensor power consumption value.

[0074] It should be noted that since passive low-power temperature sensors need to meet the requirement of low power consumption, a relatively simplified algorithm can be used to obtain the predicted power consumption value of the sensor to reduce the power consumption during prediction. In addition, prediction is performed only when the current temperature value is greater than the threshold, further achieving the purpose of reducing power consumption.

[0075] As an implementation method, the sensor predicts the power consumption value to satisfy the formula:

[0076] P=β0+β1×T

[0077] Among them, P represents the power consumption value predicted by the sensor, β0 represents the basic power consumption value when the temperature is 0, β1 represents the change of power consumption with temperature, and T represents the current temperature.

[0078] Furthermore, since the passive low-power temperature sensor needs to be fixed on the cable, in order to fix it more firmly, the passive low-power temperature sensor also includes an arc-shaped housing, the sensor module is arranged at the center of the arc-shaped housing, the four corners of the arc-shaped housing are respectively connected to four first connecting members, and the centers of the two sides of the arc-shaped housing are connected to two second connecting members;

[0079] When the passive low-power temperature sensor is installed on the cable, the four first connectors are connected in an X shape, the two second connectors are connected, and the connection points of the first connectors and the second connectors coincide and are opposite to the center position of the arc-shaped housing.

[0080] Based on the above implementation method, the present application provides a temperature acquisition system including a repeater and the above passive low-power temperature sensor, and the passive low-power temperature sensor is communicatively connected to the repeater; the repeater is used to adjust the carrier transmission power according to the current temperature after obtaining the current temperature value, if the current temperature value is greater than a threshold.

[0081] Among them, when the current temperature value is greater than the threshold, the power consumption of the passive low-power temperature sensor increases, resulting in the passive low-power temperature sensor obtaining insufficient energy from the carrier to support its operation. Therefore, the carrier transmission power of the repeater can be increased. Alternatively, when the temperature decreases, the power of the carrier transmission can also be reduced.

[0082] The adjusted carrier transmission power satisfies the formula:

[0083]

[0084] Among them, P1 represents the carrier transmission power after adjustment, P0 represents the carrier transmission power before adjustment, T1 represents the current temperature value, T2 represents the average temperature in the past preset time period, m represents the temperature influence factor, and the temperature influence factor is 0.5~1.

[0085] In one implementation, in order to ensure stable operation of the system, the repeater includes a first repeater and a second repeater, both of which are communicatively connected to the passive low-power temperature sensor, and the first repeater and the second repeater are arranged at different positions.

[0086] When the first repeater is working, the second repeater is in sleep mode; when the first repeater fails, the second repeater is working.

[0087] It can be understood that the first repeater serves as a main repeater and the second repeater serves as a backup repeater.

[0088] The carrier transmission power of the second repeater when working satisfies the formula:

[0089]

[0090] Among them, P2 represents the carrier transmission power when the second repeater is working, P3 represents the carrier transmission power when the first repeater is working, T1 represents the current temperature value, T2 represents the temperature average value of the past preset time period, m represents the temperature influence factor, and the temperature influence factor is 0.5~1; d1 represents the distance between the second repeater and the passive low power consumption temperature sensor, d2 represents the distance between the first repeater and the passive low power consumption temperature sensor, n represents the distance influence factor, and the distance influence factor is 1.5~2.

[0091] In summary, the present application provides a passive low-power temperature sensor and a temperature acquisition system, which are applied to the temperature acquisition system. The temperature acquisition system also includes a repeater. The passive low-power temperature sensor is used to be installed on a cable and communicate with the repeater. The passive low-power temperature sensor includes a radio frequency front end, an analog front end, a processing module, a sensor module and a memory. The radio frequency front end is connected to the analog front end, the processing module and the sensor module respectively, and the processing module is also connected to the analog front end, the sensor module and the memory respectively. The radio frequency front end is used to receive the energy of the signal transmitted by the repeater and the data in the carrier. The analog front end is used to provide an enable signal to the processing module. The processing module is used to process the sampling signal of the sensor module and send the processed sampling signal to the repeater through the radio frequency front end. The sensor module includes a finger capacitor, and the surface of the finger capacitor is coated with a silicone oil layer. The dielectric constant of the silicone oil layer changes with temperature. Since the present application uses a passive low-power temperature sensor to measure the temperature, there is no need to replace the power supply of the sensor, which reduces the workload of the staff.

[0092] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0093] It will be apparent to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, and that the present application can be implemented in other specific forms without departing from the spirit or essential features of the present application. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present application. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A passive low power consumption temperature sensor, characterized in that: Applied to a temperature acquisition system, the temperature acquisition system further includes a repeater, the passive low-power temperature sensor is used to be installed on a cable and communicate with the repeater; The passive low-power temperature sensor includes a radio frequency front end, an analog front end, a processing module, a sensing module and a memory, wherein the radio frequency front end is connected to the analog front end, the processing module and the sensing module respectively, and the processing module is also connected to the analog front end, the sensing module and the memory respectively; The radio frequency front end is used to receive the energy of the signal transmitted by the repeater and the data in the carrier; The analog front end is used to provide an enable signal for the processing module; The processing module is used to process the sampling signal of the sensor module and send the processed sampling signal to the repeater through the RF front end; wherein, The sensing module includes an interdigital capacitor, the surface of the interdigital capacitor is coated with a silicone oil layer, and the dielectric constant of the silicone oil layer changes with temperature.

2. The passive low power consumption temperature sensor according to claim 1, characterized in that: The processing module is also used to obtain the sensor predicted power consumption value according to the current temperature value when the current temperature value is greater than the threshold value; When the predicted power consumption value is greater than a preset value, reducing the sampling rate of the passive low power consumption temperature sensor; When the predicted power consumption value is less than a preset value, the sampling rate of the passive low power consumption temperature sensor is maintained.

3. The passive low power consumption temperature sensor according to claim 2, characterized in that: The sensor predicts the power consumption value to satisfy the formula: P=β0+β1×T Among them, P represents the power consumption value predicted by the sensor, β0 represents the basic power consumption value when the temperature is 0, β1 represents the change of power consumption with temperature, and T represents the current temperature.

4. The passive low power consumption temperature sensor according to claim 1, characterized in that: The passive low-power temperature sensor also includes an arc-shaped housing, the sensor module is arranged at the center of the arc-shaped housing, four corners of the arc-shaped housing are respectively connected to four first connecting members, and the centers of two sides of the arc-shaped housing are connected to two second connecting members; When the passive low-power temperature sensor is installed on the cable, the four first connectors are connected in an X shape, the two second connectors are connected, and the connection points of the first connectors and the second connectors coincide and are opposite to the center position of the arc-shaped housing.

5. The passive low power consumption temperature sensor according to claim 1, characterized in that: The sensing module includes a constant current source, a sensing unit, a preamplifier, a zero point adjustment unit, a signal amplifier and a range adjustment unit. The constant current source, the sensing unit, the preamplifier and the signal amplifier are connected in sequence, the preamplifier is connected to the zero point adjustment unit, and the signal amplifier is connected to the range adjustment unit.

6. The passive low power consumption temperature sensor according to claim 5, characterized in that: The sensor unit includes a cross-finger capacitor, a Schmitt trigger, and a resistor. One end of the cross-finger capacitor is grounded, and the other end is respectively connected to the input end of the Schmitt trigger and one end of the resistor. The output end of the Schmitt trigger is connected to the other end of the resistor, and the output end of the Schmitt trigger is connected to the preamplifier.

7. A temperature acquisition system, characterized in that: The temperature acquisition system comprises a repeater and a passive low-power temperature sensor according to any one of claims 1 to 6, wherein the passive low-power temperature sensor is communicatively connected to the repeater; The repeater is used to adjust the carrier transmission power according to the current temperature after obtaining the current temperature value if the current temperature value is greater than a threshold value.

8. The temperature acquisition system according to claim 7, characterized in that: The adjusted carrier transmission power satisfies the formula: Among them, P1 represents the carrier transmission power after adjustment, P0 represents the carrier transmission power before adjustment, T1 represents the current temperature value, T2 represents the average temperature in the past preset time period, m represents the temperature influence factor, and the temperature influence factor is 0.5~1.

9. The temperature acquisition system according to claim 7, characterized in that: The repeater includes a first repeater and a second repeater, the first repeater and the second repeater are both communicatively connected with the passive low-power temperature sensor, and the first repeater and the second repeater are arranged at different positions; When the first repeater is working, the second repeater is in sleep mode; When the first repeater fails, the second repeater works.

10. The temperature acquisition system according to claim 9, characterized in that: The carrier transmission power of the second repeater when working satisfies the formula: Among them, P2 represents the carrier transmission power when the second repeater is working, P3 represents the carrier transmission power when the first repeater is working, T1 represents the current temperature value, T2 represents the temperature average value of the past preset time period, m represents the temperature influence factor, and the temperature influence factor is 0.5~1; d1 represents the distance between the second repeater and the passive low power consumption temperature sensor, d2 represents the distance between the first repeater and the passive low power consumption temperature sensor, n represents the distance influence factor, and the distance influence factor is 1.5~2.

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