Temperature measurement circuit and temperature measurement system

Abstract

The utility model discloses a temperature measurement circuit and a temperature measurement system, the temperature measurement circuit is applied to a vehicle-mounted power amplifier circuit, the temperature measurement circuit comprises a temperature detection circuit and a conversion circuit, the temperature detection circuit comprises a thermosensitive element, and the thermosensitive element is used for being arranged in the environment where the vehicle-mounted power amplifier circuit is located. The temperature detection circuit is used for generating a first voltage signal in response to the temperature of the environment where the power amplifier circuit is located; the input end of the conversion circuit is connected with the output end of the temperature detection circuit, and the output end of the conversion circuit is used for being connected with a vehicle control system and used for converting the first voltage signal into a first level signal or a second level signal and outputting the first level signal or the second level signal to the vehicle control system. Wherein the level values of the first level signal and the second level signal are different. According to the scheme, the temperature measurement cost of the vehicle-mounted power amplifier can be reduced.

Description

Technical Field

[0001] This application relates to the field of automotive electronics technology, and in particular to a temperature measuring circuit and a temperature measuring system. Background Technology

[0002] For automotive components like in-vehicle audio power amplifiers, which have high power consumption and heat dissipation, prolonged overheating can easily lead to product damage. Therefore, temperature monitoring is an essential function for these components. Existing temperature measurement circuits use a separately configured control unit for temperature detection. However, because the control unit is a highly integrated microprocessor that includes memory, CPU, and other functions, its price is relatively high, resulting in significant costs associated with temperature measurement. Utility Model Content

[0003] The main technical problem addressed by this application is to provide a temperature measurement circuit and system that can reduce the temperature measurement cost of vehicle power amplifiers.

[0004] To solve the above-mentioned technical problems, one technical solution adopted in this application is to provide a temperature measuring circuit, which includes a temperature detection circuit and a conversion circuit. The temperature detection circuit includes a thermistor, which is disposed in the environment where the vehicle power amplifier circuit is located. The temperature detection circuit generates a first voltage signal in response to the ambient temperature of the power amplifier circuit. The input terminal of the conversion circuit is connected to the output terminal of the temperature detection circuit, and the output terminal of the conversion circuit is connected to the vehicle control system to convert the first voltage signal into a first level signal or a second level signal, and output the first level signal or the second level signal to the vehicle control system, wherein the level values ​​of the first level signal and the second level signal are different.

[0005] To solve the above-mentioned technical problems, another technical solution adopted in this application is to provide a temperature measurement system, which includes: a temperature measurement circuit and a vehicle control system; the temperature measurement circuit is the aforementioned temperature measurement circuit, applied to an in-vehicle power amplifier circuit; the vehicle control system is capable of communicating with the temperature measurement circuit to receive a first level signal or a second level signal generated by the temperature measurement circuit, wherein the first level signal indicates that the current temperature of the in-vehicle power amplifier circuit is higher than the preset temperature corresponding to the temperature measurement circuit, and the second level signal indicates that the current temperature of the in-vehicle power amplifier circuit is not higher than the preset temperature corresponding to the temperature measurement circuit.

[0006] The above-described solution includes a temperature detection circuit and a conversion circuit. The temperature detection circuit includes a thermistor, which is positioned within the environment where the vehicle amplifier circuit is located. The temperature detection circuit generates a first voltage signal in response to the ambient temperature of the amplifier circuit. The input terminal of the conversion circuit is connected to the output terminal of the temperature detection circuit, and the output terminal of the conversion circuit is connected to the vehicle control system. The conversion circuit converts the first voltage signal into a first-level signal or a second-level signal and outputs the first-level signal or the second-level signal to the vehicle control system. This allows the vehicle's existing control system to determine the temperature of the vehicle amplifier circuit based on the first-level signal or the second-level signal. Therefore, this application, by utilizing the temperature detection circuit and the conversion circuit, enables temperature detection using the vehicle's existing control system, eliminating the need for a separate control unit and reducing the temperature measurement cost of the vehicle amplifier. Attached Figure Description

[0007] Figure 1 This is a circuit diagram of one embodiment of the temperature measuring circuit of this application;

[0008] Figure 2 This is a schematic diagram of the framework of an embodiment of the temperature measurement system of this application;

[0009] Figure 3 This is a schematic diagram of another embodiment of the temperature measurement system of this application. Detailed Implementation

[0010] To make the purpose, technical solution and effects of this application clearer and more explicit, the following describes this application in further detail with reference to the accompanying drawings and embodiments.

[0011] It should be noted that in this article, the term "several" means at least one, and the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. The term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship. Furthermore, the term "at least one" in this article means any combination of at least two of any one or more of a plurality of elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0012] Please see Figure 1 , Figure 1 This is a circuit diagram of an embodiment of the temperature measuring circuit of this application.

[0013] Please see Figure 2 , Figure 2This is a schematic diagram of the framework of an embodiment of the temperature measurement system of this application.

[0014] Please see Figure 3 , Figure 3 This is a schematic diagram of another embodiment of the temperature measurement system of this application.

[0015] like Figure 1 As shown, the temperature sensing circuit is applied to the vehicle power amplifier circuit. The temperature sensing circuit includes a temperature detection circuit 11 and a conversion circuit 12. The temperature detection circuit 11 includes a thermistor Rtm, which is placed in the environment where the vehicle power amplifier circuit is located. The temperature detection circuit 11 generates a first voltage signal in response to the ambient temperature of the power amplifier circuit. The input terminal 121 of the conversion circuit 12 is connected to the output terminal 111 of the temperature detection circuit 11, and the output terminal 122 of the conversion circuit 12 is used to connect to the vehicle control system (…). Figure 1 (Not explicitly shown) A connection is used to convert a first voltage signal into a first level signal or a second level signal, and output the first level signal or the second level signal to the vehicle control system, wherein the level values ​​of the first level signal and the second level signal are different. Thus, the vehicle control system can determine the temperature of the on-board power amplifier circuit based on the first level signal or the second level signal.

[0016] For example, the first level signal can be a low level signal, and the second level signal can be a high level signal. These can be modified according to actual needs; no restrictions are imposed here.

[0017] Please refer to the following: Figure 3 In some embodiments, the output terminal 122 of the conversion circuit 12 is used to connect to the general purpose input / output pin 3111 of the slave unit 311 in the automotive audio bus system 31, and the master unit 312 in the automotive audio bus system 31 is connected to the vehicle control system (e.g., Figure 3 Control unit 32).

[0018] A thermistor Rtm is a component made of a sensitive material whose physical properties change with temperature. In some specific embodiments, the thermistor Rtm is a thermistor, which can be understood as a type of temperature sensor. Its working principle is based on the characteristic that the resistance of a material changes with temperature. This change can be linear or non-linear. Furthermore, its resistance can decrease or increase with increasing temperature. The thermistor can be selected according to actual needs, and no restrictions are imposed here.

[0019] like Figure 1 As shown, the thermistor Rtm is an NTC (negative temperature coefficient) thermistor, whose resistance decreases as the temperature increases.

[0020] The resistance value of the thermistor Rtm at various temperature points can be obtained by utilizing the temperature-dependent characteristic of the thermistor Rtm. The temperature detection circuit 11 then acquires different voltage values ​​corresponding to the thermistor Rtm at each temperature point, and further acquires different first voltage signals corresponding to each temperature point. In some embodiments, the temperature detection circuit 11 further includes a first pull-up resistor R1. One end of the first pull-up resistor R1 is connected to the first power supply U1, and the other end of the first pull-up resistor R1 is connected to one end of the thermistor Rtm, serving as the output terminal 111 of the temperature detection circuit 11. The other end of the thermistor Rtm is grounded.

[0021] like Figure 1 As shown, the resistance value of the thermistor Rtm is different at each temperature point. Therefore, the voltage values ​​of the first pull-up resistor R1 and the thermistor Rtm in the entire temperature detection circuit 11 are different at each temperature point. Here, the voltage value corresponding to the thermistor Rtm is used as the first voltage signal.

[0022] To meet the requirements of temperature detection, a conversion circuit is used to convert a first voltage signal corresponding to a temperature greater than a preset temperature into a first level signal, and a first voltage signal corresponding to a temperature not greater than the preset temperature into a second level signal. In some embodiments, the conversion circuit 12 includes a comparator U1A, where the first input terminal 3 of the comparator U1A serves as the input terminal 121 of the conversion circuit, the second input terminal 2 of the comparator receives a fixed second voltage signal, and the output terminal 1 of the comparator serves as the output terminal 122 of the conversion circuit. The comparator U1A compares the first voltage signal input to the first input terminal 3 with the second voltage signal input to the second input terminal 2 to output either a first level signal or a second level signal, thereby determining whether the current temperature is higher than the preset temperature.

[0023] For example, a first-level signal indicates that the current temperature of the vehicle power amplifier circuit is higher than the preset temperature corresponding to the temperature measuring circuit, and a second-level signal indicates that the current temperature of the vehicle power amplifier circuit is not higher than the preset temperature corresponding to the temperature measuring circuit. When the comparator U1A outputs a first-level signal, it indicates that the current temperature is higher than the preset temperature. Specifically, in one scenario, the higher the current temperature, the greater the voltage value of the first voltage signal output by the temperature detection circuit 11. After determining the temperature threshold to be triggered, which is the preset temperature in this article, the voltage value of the first voltage signal corresponding to the preset temperature can be obtained, and the second voltage signal can be set to the voltage value corresponding to the preset temperature. Therefore, when the current temperature is higher than the preset temperature, the first voltage signal at the first input terminal 3 of the comparator U1A is greater than the second voltage signal at the second input terminal 2, so the first-level signal is output; when the current temperature is not higher than the preset temperature, the first voltage signal at the first input terminal 3 of the comparator U1A is less than or equal to the second voltage signal at the second input terminal 2, so the second-level signal is output.

[0024] In another scenario, considering that the resistance value of the same thermistor Rtm is consistent at the same temperature point, the voltage value of the same thermistor Rtm at the same temperature point in the temperature detection circuit 11 can be different by changing the resistance value of the first pull-up resistor R1. In other words, by changing the resistance value of the first pull-up resistor R1, the first voltage signal at the same temperature point is different, while the second voltage signal at the second input terminal 2 of the fixed input comparator U1A is fixed. By adjusting the resistance value of the first pull-up resistor R1, the first voltage signal output by the temperature detection circuit 11 can be compared with the fixed second voltage signal at different preset temperatures, thereby triggering the corresponding logic output and realizing the measurement of different preset temperatures.

[0025] like Figure 1 As shown, the temperature measuring circuit may also include a voltage divider circuit 13 for outputting the aforementioned fixed second voltage signal. The voltage divider circuit 13 includes a second pull-up resistor R2 and a voltage divider resistor R3. One end of the second pull-up resistor R2 is connected to the second power supply U2, and the other end is connected to one end of the voltage divider resistor R3 and the second input terminal 2 of the comparator U1A. The other end of the voltage divider resistor R3 is grounded.

[0026] The first power supply terminal 8 of comparator U1A is connected to the fixed power supply U3, and the second power supply terminal 4 of comparator U1A is grounded. Other circuits in the temperature measurement circuit are also connected to other power supplies, and all other power supplies have the same voltage as the fixed power supply.

[0027] In some specific embodiments, all other power sources may be fixed power sources, and this is not a limitation.

[0028] Considering that the first input terminal 3 of comparator U1A in conversion circuit 12 typically has a high impedance, but directly inputting voltage may cause excessive current, damaging the temperature sensing circuit, a high-impedance resistor can be connected to the first input terminal of comparator U1A in the temperature sensing circuit to provide current limiting protection. In some embodiments, the temperature sensing circuit further includes a first resistor R4, and the output terminal 111 of temperature detection circuit 11 is connected to the input terminal 121 of conversion circuit 12 through the first resistor R4.

[0029] Considering the potential noise interference in the temperature measurement circuit environment, at least one filtering element can be provided to improve the performance and anti-interference capability of the temperature measurement circuit. In some embodiments, the temperature measurement circuit further includes a first filtering capacitor C1, the two ends of which are respectively connected to the output terminal 111 of the temperature detection circuit 11 and the ground terminal.

[0030] In some embodiments, the temperature measuring circuit further includes a second filter capacitor C2, the two ends of which are connected to the output terminal 122 of the conversion circuit and the ground terminal, respectively.

[0031] Of course, in some embodiments, the temperature measuring circuit also includes a third filter capacitor C3, the two ends of which are connected to the fixed power supply U3 and the ground terminal, respectively.

[0032] Considering the potential hysteresis in the application of comparator U1A, introducing a feedback circuit can improve the comparator's response speed to changes in the first and second voltage signals. That is, the comparator can more quickly identify and respond to the difference between these two voltage signals, thereby improving the sensitivity and accuracy of the entire temperature measurement circuit. Figure 1 As shown, the temperature measuring circuit also includes a feedback circuit 14, which is connected to the input terminal 121 and the output terminal 122 of the conversion circuit 12.

[0033] In some embodiments, the feedback circuit 14 can be a positive feedback circuit or a negative feedback circuit, and the choice can be made according to actual needs. No restrictions are imposed here.

[0034] In some specific embodiments, the feedback circuit 14 includes a third resistor R5.

[0035] In some embodiments, the temperature sensing circuit further includes a stabilizing resistor R6, with its two ends connected to the third power supply U4 and the output terminal of the conversion circuit 12, respectively, to stabilize the level signal output by the conversion circuit 12. Specifically, the stabilizing resistor R6 can pull the uncertain state of the output terminal high.

[0036] like Figure 1 As shown, the temperature measuring circuit also includes a stabilizing resistor R6, which can be understood as a pull-up resistor to ensure that the output terminal can be stably maintained at a high level.

[0037] To facilitate subsequent debugging, a test point, which can be a resistor, can be set in the temperature measurement circuit. In some embodiments, the temperature measurement circuit also includes a second resistor R7, and the output of the conversion circuit 12 is connected to the vehicle control system (not explicitly shown in the figure) through the second resistor R7. For example, the second resistor R7 can be selected as a 0-ohm resistor. However, it should be noted that a 0-ohm resistor is not a truly zero-resistance resistor, but rather one whose resistance is very close to 0 ohms. The above solution not only maintains the continuity of the circuit but also provides a test interface without interfering with the normal operation of the circuit.

[0038] Of course, the first resistor R4, the first filter capacitor C1, the feedback circuit 14, the second filter capacitor C2, the stabilizing resistor R6, and the second resistor R7 mentioned above can be freely combined and added to the temperature measuring circuit according to actual needs. There are no restrictions here.

[0039] like Figure 2 , Figure 3 As shown, the temperature measurement system 20 includes a temperature measurement circuit 21 and a vehicle control system 22 (e.g., Figure 3 The control unit 32 is included in the system. Temperature measurement circuit 21 is applied to the vehicle power amplifier circuit 33, and temperature measurement circuit 21 can be any of the aforementioned temperature measurement circuits. The vehicle control system 22 can communicate with temperature measurement circuit 21 to receive a first-level signal or a second-level signal generated by temperature measurement circuit 21. The first-level signal indicates that the current temperature of the vehicle power amplifier circuit 33 is higher than the preset temperature corresponding to temperature measurement circuit 21, and the second-level signal indicates that the current temperature of the vehicle power amplifier circuit 33 is not higher than the preset temperature corresponding to temperature measurement circuit 21.

[0040] In some embodiments, there are multiple temperature measuring circuits 21, and each temperature measuring circuit 21 corresponds to a different preset temperature.

[0041] In some embodiments, the temperature measurement system further includes an automotive audio bus system 31, which includes a slave unit 311 and a master unit 312 communicating via a bus. The temperature measurement circuit is connected to the general purpose input / output pin 3111 of the slave unit 311, and the master unit 312 is connected to the vehicle control system 22 (e.g., vehicle audio bus system 312). Figure 3 The control unit 32 in the middle is connected.

[0042] like Figure 3 As shown, the temperature measurement system includes two temperature measurement circuits 21, each corresponding to a different preset temperature. The output of the first temperature measurement circuit 21 is connected to a general-purpose input / output pin 3111 of the slave device, and the output of the second temperature measurement circuit is connected to another general-purpose input / output pin 3111 of the slave device. It should be noted that TEMP1 refers to the level signal (either a first or second level signal) output by the first temperature measurement circuit, and TEMP2 refers to the level signal (either a first or second level signal) output by the second temperature measurement circuit.

[0043] In some embodiments, the vehicle control system 22 is a vehicle infotainment system control unit 32. For example, the vehicle infotainment system control unit 32 may be an MCU (microcontroller unit) module.

[0044] like Figure 3 As shown, TEMP1 and TEMP2 can communicate via the vehicle audio bus system 31 to input TEMP1 and TEMP2 into the vehicle's control unit 32.

[0045] In some embodiments, the vehicle control system 22 is configured to output a cooling command to the vehicle power amplifier circuit 33 in response to receiving a first level signal, the cooling command including a mute command.

[0046] In some embodiments, the vehicle control system 22 is configured to output a cooling command to the vehicle power amplifier circuit 33 in response to receiving a first level signal, the cooling command including stopping the voltage boost.

[0047] In some embodiments, the vehicle control system 22 is configured to output a cooling command to the vehicle power amplifier circuit in response to receiving a first level signal. The cooling command includes a mute command and a stop voltage boost command.

[0048] For example, in response to the received TEMP1 signal being a first-level signal, a cooling command MUTE is output to the vehicle power amplifier circuit 33. The cooling command MUTE includes a mute command and a stop boost command. Similarly, the cooling command MUTE can be communicated via the vehicle audio bus system 31.

[0049] Although this application has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to this application without departing from the spirit and scope of this application as defined by the appended claims, and all such changes shall be within the scope of protection of this application.

Claims

1. A temperature measuring circuit, characterized in that, The temperature measuring circuit is used in the vehicle power amplifier circuit, and the temperature measuring circuit includes: A temperature detection circuit includes a thermistor, the thermistor being disposed in the environment where the vehicle power amplifier circuit is located, and the temperature detection circuit being used to generate a first voltage signal in response to the ambient temperature where the power amplifier circuit is located. A conversion circuit is provided, wherein the input terminal of the conversion circuit is connected to the output terminal of the temperature detection circuit, and the output terminal of the conversion circuit is used to connect to the vehicle control system. The conversion circuit is used to convert the first voltage signal into a first level signal or a second level signal, and output the first level signal or the second level signal to the vehicle control system, wherein the level values ​​of the first level signal and the second level signal are different.

2. The temperature measuring circuit according to claim 1, characterized in that, The output of the conversion circuit is used to connect to the general-purpose input / output pins of the slave unit in the automotive audio bus system, and the master unit in the automotive audio bus system is connected to the vehicle control system.

3. The temperature measuring circuit according to claim 1, characterized in that, The thermal element is a thermistor; And / or, the temperature detection circuit further includes a first pull-up resistor, one end of which is connected to a first power supply, the other end of which is connected to one end of the thermistor and serves as the output terminal of the temperature detection circuit, and the other end of the thermistor is grounded.

4. The temperature measuring circuit according to claim 1, characterized in that, The conversion circuit includes a comparator, the first input terminal of the comparator serves as the input terminal of the conversion circuit, the second input terminal of the comparator receives a fixed second voltage signal, and the output terminal of the comparator serves as the output terminal of the conversion circuit.

5. The temperature measuring circuit according to claim 4, characterized in that, The temperature measuring circuit further includes a voltage divider circuit, wherein the voltage divider circuit includes a second pull-up resistor and a voltage divider resistor, one end of the second pull-up resistor is connected to a second power supply, and the other end is connected to one end of the voltage divider resistor and the second input terminal of the comparator, respectively, and the other end of the voltage divider resistor is grounded.

6. The temperature measuring circuit according to claim 1, characterized in that, The temperature measuring circuit also includes at least one of the following components or circuits: The first resistor is used to connect the output terminal of the temperature detection circuit to the input terminal of the conversion circuit. The first filter capacitor is connected to the output terminal of the temperature detection circuit and the ground terminal, respectively. A feedback circuit is provided, which is connected to the input and output terminals of the conversion circuit, respectively. The second filter capacitor is connected to the output terminal and ground terminal of the conversion circuit, respectively. A stabilizing resistor, the two ends of which are respectively connected to a third power supply and the output terminal of the conversion circuit, is used to stabilize the level signal output by the conversion circuit; The output of the conversion circuit is connected to the vehicle control system via the second resistor.

7. The temperature measuring circuit according to claim 6, characterized in that, The feedback circuit includes a third resistor.

8. A temperature measurement system, characterized in that, The temperature measurement system includes: A temperature measuring circuit, applied to an automotive power amplifier circuit, is the temperature measuring circuit described in any one of claims 1-7; The vehicle control system is capable of communicating with the temperature measuring circuit and receiving a first-level signal or a second-level signal generated by the temperature measuring circuit. The first-level signal indicates that the current temperature of the vehicle power amplifier circuit is higher than the preset temperature corresponding to the temperature measuring circuit, and the second-level signal indicates that the current temperature of the vehicle power amplifier circuit is not higher than the preset temperature corresponding to the temperature measuring circuit.

9. The temperature measurement system according to claim 8, characterized in that, There are multiple temperature measuring circuits, and each temperature measuring circuit corresponds to a different preset temperature.

10. The temperature measurement system according to claim 8, characterized in that, The temperature measurement system also includes an automotive audio bus system, which includes a slave unit and a master unit that communicate via a bus. The temperature measurement circuit is connected to the general purpose input / output pins of the slave unit, and the master unit is connected to the vehicle control system. And / or, the vehicle control system is a control unit of the vehicle infotainment system; And / or, the vehicle control system is configured to output a cooling command to the vehicle power amplifier circuit in response to receiving the first level signal, the cooling command including at least one of a mute command and a stop voltage boost command.

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