Circuit for maximum temperature output of temperature sampling of multiple radiators

Abstract

The utility model discloses a circuit for maximum temperature output of temperature sampling of a plurality of radiators. The circuit comprises an NTC thermistor; a corresponding follower is connected to the position of each NTC thermistor, a diode is arranged at the reverse input end and the output end of each follower, the reverse input ends of all follower circuits are connected together, and a pull-up resistor is arranged on the output side of temperature sampling of the NTC thermistors. The circuit is suitable for an occasion where the highest temperature is extracted by a hardware circuit in a system needing a plurality of temperature sampling points, the circuit is simple and reliable in design and low in cost, the temperatures of a plurality of radiators can be acquired by using fewest components, and finally, only one path with the highest temperature is output to an MCU (Microprogrammed Control Unit) to participate in calculation.

Description

Technical Field

[0001] The utility model relates to the technical field of sampling circuits, in particular to a circuit for sampling the temperatures of a plurality of radiators and outputting the highest temperature. Background Art

[0002] At present, the new energy industry is developing rapidly. With the application of more and more IGBT single tubes and silicon carbide single tubes in power electronic equipment, the system has also increased the demand for radiator temperature sampling. Generally speaking, the number of analog sampling channels of the controller is small and the resources are relatively precious. For the numerous NTC temperature sampling needs, it is impossible to occupy one ADC channel for each temperature sampling. Therefore, it is necessary to simplify the circuit to realize multiple NTC temperature sampling inputs, and output only one highest temperature to be sent to the controller for calculation. Utility Model Content

[0003] Therefore, the purpose of the present invention is to provide a circuit for sampling the maximum temperature of multiple radiator temperatures and outputting it. The circuit is suitable for extracting the maximum temperature using a hardware circuit in a system that requires multiple temperature sampling points. The circuit is simple and reliable in design, low in cost, and can use a minimum of components to collect the temperatures of multiple radiators and finally output only the highest temperature to the MCU for calculation.

[0004] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solution: a circuit for sampling the highest temperature output of multiple radiator temperatures, comprising an NTC thermistor; each NTC thermistor position is connected to a corresponding follower, the reverse input end of the follower and the output end of the follower are configured with a diode, and the reverse input ends of all follower circuits are connected together, and the output side of the NTC thermistor temperature sampling is configured with a pull-up resistor.

[0005] As a preferred solution of the circuit for sampling the highest temperature of multiple radiators and outputting the temperature of the radiator according to the present invention, the chip in the pull-up resistor is an 8-to-1 analog multi-channel selector;

[0006] Among them, the analog multi-channel selector is used to expand the input of temperature sampling.

[0007] As a preferred solution of the circuit for sampling the temperatures of multiple radiators and outputting the highest temperature described in the present invention, the model of the analog multi-channel selector is CD4051BM96.

[0008] As a preferred solution of the circuit for sampling the highest temperature of multiple radiators described in the present invention, the analog multi-channel selector selects specific channels from Y0 to Y7 through S0, S1, and S2 to output to the subsequent MCU;

[0009] The output side is impedance matched through a follower.

[0010] As a preferred solution of the circuit for sampling the highest temperature of multiple radiators and outputting the temperature of the radiator described in the present invention, the follower rear stage uses a diode to perform voltage clamping to protect the MCU that collects data.

[0011] As a preferred solution of the circuit for sampling the highest temperature output of multiple radiator temperatures described in the utility model, wherein the temperature detection of two radiator NTC thermistors includes two NTC thermistor values;

[0012] The temperature detection of four radiator NTC thermistors includes four NTC thermistor values.

[0013] Compared with the prior art, the advantages of the present invention are:

[0014] This circuit offers high temperature sampling accuracy without requiring additional hardware circuitry to compensate for errors. The hardware is simple and low-cost, and the software algorithm is simple to implement, eliminating the need for complex logic operations. Theoretically, this circuit can simultaneously support numerous radiator temperature sampling points and directly extract the highest temperature sampled data. The front-end circuit is used to extract the highest radiator temperature, while the back-end circuit is used to expand other analog sampling capabilities. The back-end circuit also protects the main controller pins. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below in conjunction with the accompanying drawings and detailed embodiments. Obviously, 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 inventive labor. Among them:

[0016] Figure 1 This is the principle circuit diagram of the NTC temperature detection of two radiators in this utility model;

[0017] Figure 2 This is the principle circuit diagram of the NTC temperature detection of four radiators in this utility model;

[0018] Figure 3 This is the principle circuit diagram of the pull-up resistor of the utility model. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0020] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. People skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific implementation methods disclosed below.

[0021] Next, the present invention is described in detail with reference to schematic diagrams. For ease of illustration, cross-sectional views of device structures may be partially enlarged and not to scale when describing the embodiments of the present invention. Furthermore, the schematic diagrams are merely illustrative and should not limit the scope of protection of the present invention. Furthermore, in actual production, three-dimensional dimensions, including length, width, and depth, should be included.

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0023] The utility model provides a circuit for sampling the maximum temperature of multiple radiators and outputting the maximum temperature. The circuit is suitable for extracting the maximum temperature using a hardware circuit in a system requiring multiple temperature sampling points. The circuit is simple and reliable in design, low in cost, and can use a minimum of components to collect the temperatures of multiple radiators and finally output only the highest temperature to an MCU for calculation.

[0024] Figure 1-Figure 3 The figure shows the overall structure of a circuit for sampling the highest temperature output of multiple radiators according to the present invention. Figure 1-3 The main structure of this embodiment includes: an NTC thermistor; each NTC thermistor position is connected to a corresponding follower, the inverting input terminal of the follower and the output terminal of the follower are configured with a diode, and the inverting input terminals of all follower circuits are connected together, and the output side of the NTC thermistor temperature sampling is configured with a pull-up resistor;

[0025] In practice, each NTC temperature sensor for heat sink temperature sensing requires only one follower circuit. A diode is placed between the follower's inverting input and the follower's output. The inverting inputs of all follower circuits are connected together. This circuit can support two, three, four, or even N channels of heat sink temperature sampling. After processing, only the highest temperature sample is output, with N being greater than or equal to 2. A pull-up resistor is placed on the output of the temperature sensor, ensuring forward conduction of the diode in the channel with the lowest temperature during power-up, placing the operational amplifier in a negative feedback mode. The temperature-sampling NTC resistor has a negative temperature coefficient, meaning its resistance decreases with increasing temperature. The pull-up resistors are integrated into an 8-to-1 analog multichannel selector, which expands the temperature sampling inputs for greater flexibility. The selector in the image above is the CD4051BM96. S0, S1, and S2 control which channel, Y0-Y7, is output to the subsequent MCU. The output side uses a follower to perform impedance matching to make the data read by the MCU more accurate. The follower's post-stage uses a diode as a voltage clamp to protect the MCU that collects data. Since the operational amplifier is in a negative feedback regulation state after the diode in the circuit is forward-conducted, according to the virtual short and virtual break principle of the operational amplifier, the common end output of all followers is the lowest voltage data of all input signals. The operational amplifier with the lowest voltage input can form negative feedback because its configured diode is forward-conducted. Other operational amplifiers with higher input voltages cannot be turned on because the anode voltage of the diode is clamped to the lowest input voltage. Therefore, other operational amplifiers cannot form negative feedback.

[0026] While the present invention has been described above with reference to specific embodiments, various modifications may be made and equivalent components may be substituted without departing from the scope of the present invention. In particular, as long as no structural conflicts exist, the various features of the embodiments disclosed herein may be combined with one another in any manner, and the omission of an exhaustive description of these combinations in this specification is solely for the sake of space and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A circuit for sampling the highest temperature of multiple radiator temperatures and outputting the highest temperature, comprising an NTC thermistor; characterized in that: Each NTC thermistor position is connected to a corresponding follower, the reverse input end and the output end of the follower are configured with a diode, and the reverse input ends of all follower circuits are connected together, and the output side of the NTC thermistor temperature sampling is configured with a pull-up resistor.

2. A circuit for sampling and outputting the highest temperature of multiple radiator temperatures according to claim 1, characterized in that: The chip in the pull-up resistor is an 8-to-1 analog multi-channel selector; Among them, the analog multi-channel selector is used to expand the input of temperature sampling.

3. The circuit for sampling and outputting the highest temperature of multiple radiator temperatures according to claim 2, characterized in that: The model of the analog multi-channel selector is CD4051BM96.

4. The circuit for sampling and outputting the highest temperature of multiple radiator temperatures according to claim 3, characterized in that: The analog multi-channel selector selects specific channels from Y0 to Y7 through S0, S1, and S2 to output to the subsequent MCU; The output side is impedance matched through a follower.

5. The circuit for sampling and outputting the highest temperature of multiple radiator temperatures according to claim 4, characterized in that: The follower's rear stage uses a diode to perform voltage clamping to protect the MCU that collects data.

6. The circuit for sampling the temperature of multiple radiators and outputting the highest temperature according to claim 5, characterized in that: The temperature detection of two radiator NTC thermistors includes two NTC thermistor values; The temperature detection of four radiator NTC thermistors includes four NTC thermistor values.

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