Signal transmission circuit, electronic equipment and control system

Abstract

The utility model discloses a signal transmission circuit, an electronic device and a control system, comprising a temperature sensor, a conversion circuit, an isolation circuit and a digital signal processor which are connected in sequence, the temperature sensor detects temperature change and converts temperature information into an electric signal, the conversion circuit converts the electric signal into a frequency signal, and the digital signal processor is connected with the isolation circuit. The isolation circuit isolates the frequency signal to obtain a first target signal, and the digital signal processor processes the first target signal to obtain a second target signal for temperature display. Compared with the related technology (a single signal is obtained by adopting a comparator for simple comparison and is transmitted to the DSP), the technical scheme has the advantages that the analog signal is converted into the signals with different frequencies by utilizing the conversion circuit, and the signal integrity is better. Meanwhile, the isolation circuit is adopted, electromagnetic interference and the like are avoided, electrical safety is guaranteed, and the circuit is suitable for high-voltage and high-frequency application environments.

Description

Technical Field

[0001] This utility model relates to the field of signal transmission technology, and in particular to a signal transmission circuit, electronic device and control system. Background Technology

[0002] In industrial control, medical equipment, electronic measurement, and automation systems, signal isolation and transmission are crucial for ensuring system stability and security. Many sensors (such as thermistors, pressure sensors, and current sensors) output analog signals, while control systems in related technologies typically need to convert these analog signals into digital signals for processing.

[0003] In practical applications, signal isolation is used not only to prevent electromagnetic interference and ensure data integrity, but also for electrical safety protection in high-voltage systems, medical equipment, and harsh industrial environments. For example, in high-voltage substations and electromechanical equipment monitoring systems, it is necessary to ensure stable and reliable signal transmission between low-voltage control circuits and high-voltage circuits to avoid the risks associated with direct electrical connections. If signal transmission between different electrical environments does not meet isolation requirements, it can lead to electromagnetic interference and electrical safety issues.

[0004] It is evident that the signal transmission methods of related technologies often fail to meet strict isolation requirements, leading to electromagnetic interference and electrical safety issues, or deficiencies in signal integrity and transmission efficiency. Utility Model Content

[0005] The main objective of this invention is to provide a signal transmission circuit, electronic device, and control system to at least solve the technical problems of electromagnetic interference and insufficient electrical safety in signal transmission in related technologies.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A first aspect of this utility model provides a signal transmission circuit, the signal transmission circuit comprising a temperature sensor, a conversion circuit, an isolation circuit, and a digital signal processor connected in sequence.

[0008] The temperature sensor is used to detect temperature changes and convert temperature information into an electrical signal. The conversion circuit is used to convert the electrical signal into a frequency signal. The isolation circuit is used to isolate the frequency signal to obtain a first target signal. The digital signal processor is used to process the first target signal to obtain a second target signal for temperature display.

[0009] Based on the first aspect, the temperature sensor includes a thermistor and a first resistor, one end of the thermistor and one end of the first resistor are both electrically connected to a power supply, and the other end of the thermistor and the other end of the first resistor are both electrically connected to the conversion circuit.

[0010] Based on the first aspect, the conversion circuit includes a comparison circuit and a charge / discharge circuit; the comparison circuit is used to compare the electrical signal with a preset reference voltage to generate a corresponding comparison signal; the charge / discharge circuit is used to process the comparison signal by charging and discharging, and convert the voltage signal into a frequency signal.

[0011] Based on the first aspect, the comparison circuit includes a comparator, a first feedback resistor, and a second feedback resistor; the positive input terminal of the comparator is electrically connected to the temperature sensor, and the negative input terminal is used to receive a reference voltage; the first feedback resistor and the second feedback resistor are both electrically connected between the output terminal and the input terminal of the comparator.

[0012] Based on the first aspect, the charging and discharging circuit includes a transistor, a first capacitor, a second capacitor, a charging resistor, and a discharging resistor; the base of the transistor is electrically connected to the output terminal of the comparator circuit, the first capacitor and the second capacitor are both electrically connected between the collector and emitter of the transistor, the charging resistor is electrically connected between the collector of the transistor and the isolation circuit, and the discharging resistor is electrically connected between the emitter of the transistor and ground.

[0013] Based on the first aspect, the isolation circuit includes a digital isolation chip, an input resistor, and a filter capacitor; the input resistor is electrically connected to the input terminal of the digital isolation chip, and the filter capacitor is electrically connected between the power supply terminal of the digital isolation chip and ground.

[0014] Based on the first aspect, the reference voltage satisfies the following relationship:

[0015]

[0016] Among them, V ref R1 represents the reference voltage, R2 represents the resistance of the first feedback resistor, R3 represents the resistance of the second feedback resistor, and U1 represents the power supply voltage.

[0017] Based on the first aspect, the input signal frequency of the digital isolation chip satisfies the following relationship:

[0018]

[0019] Where f represents the input signal frequency, R NTCC1 represents the resistance value of the thermistor, and C2 represents the capacitance value of the charging capacitor. V ref Indicates the reference voltage, V C1 V represents the voltage after the charging capacitor has discharged, and C2 represents the capacitance of the discharging capacitor. C2 This represents the voltage after the capacitor has discharged, V. th This indicates the threshold voltage of the transistor.

[0020] A second aspect of this invention provides an electronic device, including a device body and a signal transmission circuit as described in the first aspect.

[0021] A third aspect of this utility model provides a control system, including a host computer and electronic equipment as described in the second aspect.

[0022] This utility model relates to a signal transmission circuit, electronic device, and control system, comprising a temperature sensor, a conversion circuit, an isolation circuit, and a digital signal processor connected in sequence. Compared to related technologies (which use a comparator for simple comparison to obtain a single signal for transmission to a DSP for control), this technical solution utilizes a conversion circuit to convert analog signals into signals of different frequencies, resulting in better signal integrity. Simultaneously, the use of an isolation circuit (ensuring isolation requirements are met) avoids electromagnetic interference and other issues, ensuring electrical safety and making it suitable for high-voltage, high-frequency applications. Furthermore, the frequency signal transmission parameters can be flexibly adjusted according to different application environments and signal requirements, demonstrating wide applicability. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. 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 creative effort.

[0024] Figure 1 A schematic block diagram of the signal transmission circuit provided in an embodiment of this application;

[0025] Figure 2 This is a schematic diagram of the specific circuit connection of the signal transmission circuit provided in the embodiments of this application. Detailed Implementation

[0026] 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 a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0027] It should be noted that related terms such as "first" and "second" can be used to describe various components, but these terms do not limit the component. These terms are only used to distinguish one component from another. For example, without departing from the scope of this utility model, the first component can be referred to as the second component, and the second component can similarly be referred to as the first component. The term "and / or" refers to any one or more combinations of related and descriptive terms.

[0028] The technical issues mentioned in the related technologies include the following:

[0029] 1. Efficient conversion of analog signals to digital signals: In related technologies, analog signals (such as temperature change signals from thermistors) are difficult to use directly for digital processing and display.

[0030] 2. Signal isolation and transmission reliability: In industrial or complex environments, signal transmission needs to meet isolation requirements to prevent interference and improve security.

[0031] 3. Achieve voltage signal to frequency signal conversion: Signal conversion is achieved through a comparison circuit and a charging / discharging section, solving the problems of high complexity and high cost.

[0032] To resolve the above technical issues, please refer to Figure 1 This embodiment provides a signal transmission circuit, which includes a temperature sensor 10, a conversion circuit 20, an isolation circuit 30, and a digital signal processor 40 connected in sequence.

[0033] Specifically, the output terminal of the temperature sensor 10 is electrically connected to the input terminal of the conversion circuit 20, the output terminal of the conversion circuit 20 is electrically connected to the input terminal of the isolation circuit 30, and the output terminal of the isolation circuit 30 is electrically connected to the digital signal processor 40.

[0034] When the signal transmission circuit is in operation, the temperature sensor 10 is used to detect temperature changes and convert the temperature information into an electrical signal (analog electrical signal). The conversion circuit 20 is used to convert the electrical signal into a frequency signal. The isolation circuit 30 is used to isolate the frequency signal to obtain a first target signal. The digital signal processor 40 is used to process the first target signal to obtain a second target signal for temperature display or a third target signal that can be used for calculation (that is, the digital signal processor 40 analyzes and calculates the isolated frequency signal and converts it into displayable temperature data).

[0035] As can be seen, the signal transmission circuit of this application integrates functions such as signal acquisition, signal conversion, signal isolation, and signal processing. Compared with related technologies (which use comparators to perform simple comparisons to obtain a single signal for transmission to the DSP for control), this technical solution converts analog signals into signals of different frequencies through a conversion circuit, resulting in better signal integrity. Simultaneously, the use of an isolation circuit (to meet isolation requirements) avoids electromagnetic interference and ensures electrical safety, making it suitable for high-voltage, high-frequency applications. Furthermore, the frequency signal transmission parameters can be flexibly adjusted according to different application environments and signal requirements, demonstrating wide applicability.

[0036] Please see Figure 2 The following is a detailed description of each part of the signal transmission circuit (temperature sensor 10, conversion circuit 20, isolation circuit 30, digital signal processor 40):

[0037] In an optional embodiment of this application, the temperature sensor includes a thermistor NTC and a first resistor R1. One end of the thermistor NTC and one end of the first resistor R1 are both electrically connected to the power supply U1, and the other end of the thermistor NTC and the other end of the first resistor R1 are both electrically connected to the conversion circuit.

[0038] Specifically, the resistance of the thermistor NTC changes with temperature: the resistance decreases as the temperature rises and increases as the temperature falls. The first resistor (fixed resistor) R1, as part of the voltage divider circuit, together with the thermistor NTC, forms a temperature-dependent voltage signal.

[0039] In an optional embodiment of this application, the conversion circuit includes a comparator circuit (U2, R2, R3) and a charge / discharge circuit (Q1, C1, C2, R4, R5).

[0040] Specifically, the comparator circuit is used to compare the electrical signal with a preset reference voltage to generate a corresponding comparison signal, and the charge-discharge circuit is used to charge and discharge the periodically changing comparison signal and convert the resulting voltage signal into a frequency signal so that it can be transmitted more stably to subsequent circuits for processing.

[0041] In an optional embodiment of this application, the comparison circuit includes a comparator U2, a first feedback resistor R2, and a second feedback resistor R3.

[0042] Specifically, the positive input terminal of comparator U2 is electrically connected to the temperature sensor, and the negative input terminal is used to receive the reference voltage. The first feedback resistor R2 and the second feedback resistor R3 are both electrically connected between the output and input terminals of comparator U2. That is, through the synergistic effect of comparator U2, feedback resistors R2 and R3, the comparator circuit can stably and efficiently convert the temperature signal into a digital signal, providing reliable data input for subsequent signal processing.

[0043] In an optional embodiment of this application, the charging and discharging circuit includes a transistor Q1, a first capacitor C1, a second capacitor C2, a charging resistor R4, and a discharging resistor R5.

[0044] Specifically, the base of transistor Q1 is electrically connected to the output of the comparator circuit. The first capacitor C1 and the second capacitor C2 are both electrically connected between the collector and emitter of transistor Q1. The charging resistor R4 is electrically connected between the collector of transistor Q1 and the isolation circuit. The discharging resistor R5 is electrically connected between the emitter of transistor Q1 and ground. In this optional embodiment, the charging and discharging circuit consists of transistor Q1, first capacitor C1, second capacitor C2, charging resistor R4, and discharging resistor R5. It is mainly used to charge and discharge the signal output from the comparator circuit and convert the voltage signal into a frequency signal. This design utilizes the switching characteristics of the transistor and the charging and discharging characteristics of the capacitor-resistor network to achieve periodic signal changes, providing a stable frequency signal input for the subsequent isolation circuit.

[0045] In an optional embodiment of this application, the isolation circuit includes a digital isolation chip U3, an input resistor R6, and a filter capacitor C3.

[0046] Specifically, the input resistor R6 is electrically connected to the output terminal of the digital isolation chip U3, and the filter capacitor C3 is electrically connected between the power supply terminal of the digital isolation chip U3 and ground. That is, through the synergistic effect of the digital isolation chip U3, the input resistor R6, and the filter capacitor C3, the isolation circuit achieves efficient isolation and stable signal transmission, ensuring that the signal is transmitted completely to the digital signal processor, providing a reliable foundation for subsequent temperature signal calculation and display.

[0047] In the design process of the entire signal transmission circuit, the first step is to select a suitable digital isolator and determine its primary and secondary power supply voltage ranges. The digital isolator is a key component for achieving signal isolation. This technical solution uses a CMOS-based digital isolator, with the isolation channel isolated by a dual-capacitor silicon dioxide insulated gate phase, exhibiting excellent insulation, high anti-interference capability, and low power consumption. The secondary power supply of this solution is compatible with the DSP power supply, reducing circuit complexity.

[0048] In an optional embodiment of this application, the reference voltage satisfies the following relationship:

[0049]

[0050] Among them, V refR1 represents the reference voltage, R2 represents the resistance of the first feedback resistor, R3 represents the resistance of the second feedback resistor, and U1 represents the power supply voltage. Typically, the reference voltage should be set within a certain percentage of the power supply voltage U1 to ensure the acquireability of the frequency signal.

[0051] In an optional embodiment of this application, the input signal frequency of the digital isolation chip satisfies the following relationship:

[0052]

[0053] Where f represents the input signal frequency, R NTC C1 represents the resistance value of the thermistor, and C2 represents the capacitance value of the charging capacitor. V ref Indicates the reference voltage, V C1 V represents the voltage after the charging capacitor has discharged, and C2 represents the capacitance of the discharging capacitor. C2 This represents the voltage after the capacitor has discharged, V. th This indicates the threshold voltage of the transistor.

[0054] It should be noted that the thermistor NTC in this embodiment is a sensor resistor, a negative temperature coefficient thermistor, meaning its resistance value RNTC decreases with temperature. The relationship between its resistance value and temperature can be determined using a calibration formula or a temperature-resistance curve table. As the resistance value changes, the charging and discharging time of capacitor C1 changes, thus altering the input signal frequency of the digital isolator.

[0055] The converted input frequency signal is transmitted to the I / O port of the digital signal processor 40 through a digital isolator. The processing module inside the digital signal processor 40 can further process the frequency signal, such as decoding, filtering or calculation, and finally realize the digital display of temperature or other control functions.

[0056] This application also provides an electronic device, which includes a device body and a signal transmission circuit as described in the above embodiments.

[0057] This application also provides a control system, including a host computer and the electronic equipment described in the above embodiments.

[0058] This utility model relates to a signal transmission circuit, electronic device, and control system, comprising a temperature sensor, a conversion circuit, an isolation circuit, and a digital signal processor connected in sequence. Compared to related technologies (which use a comparator for simple comparison to obtain a single signal for transmission to a DSP for control), this technical solution utilizes a conversion circuit to convert analog signals into signals of different frequencies, resulting in better signal integrity. Simultaneously, the use of an isolation circuit avoids electromagnetic interference and ensures electrical safety, making it suitable for high-voltage, high-frequency applications. Furthermore, the frequency signal transmission parameters can be flexibly adjusted according to different application environments and signal requirements, offering wide applicability. It also features high transmission efficiency; through the coordinated operation of a signal amplifier and a filter, the transmission efficiency and stability of the frequency signal are improved, while signal transmission loss is reduced.

[0059] The specific embodiments of the utility model have been described in detail above, but they are only examples, and the utility model is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications or substitutions to the utility model are also within the scope of the utility model. Therefore, all equivalent transformations, modifications, and improvements made without departing from the spirit and principles of the utility model should be covered within the scope of the utility model.

Claims

1. A signal transmission circuit, characterized in that, The signal transmission circuit includes a temperature sensor, a conversion circuit, an isolation circuit, and a digital signal processor connected in sequence. The temperature sensor is used to detect temperature changes and convert temperature information into an electrical signal. The conversion circuit is used to convert the electrical signal into a frequency signal. The isolation circuit is used to isolate the frequency signal to obtain a first target signal. The digital signal processor is used to process the first target signal to obtain a second target signal for temperature display.

2. The signal transmission circuit as described in claim 1, characterized in that, The temperature sensor includes a thermistor and a first resistor. One end of the thermistor and one end of the first resistor are both electrically connected to a power supply, and the other end of the thermistor and the other end of the first resistor are both electrically connected to the conversion circuit.

3. The signal transmission circuit as described in claim 2, characterized in that, The conversion circuit includes a comparator circuit and a charge / discharge circuit; The comparison circuit is used to compare the electrical signal with a preset reference voltage and generate a corresponding comparison signal; The charging and discharging circuit is used to charge and discharge the comparison signal and convert the voltage signal into a frequency signal.

4. The signal transmission circuit as described in claim 3, characterized in that, The comparison circuit includes a comparator, a first feedback resistor, and a second feedback resistor; The positive input terminal of the comparator is electrically connected to the temperature sensor, and the negative input terminal is used to receive the reference voltage; the first feedback resistor and the second feedback resistor are both electrically connected between the output terminal and the input terminal of the comparator.

5. The signal transmission circuit as described in claim 4, characterized in that, The charging and discharging circuit includes a transistor, a first capacitor, a second capacitor, a charging resistor, and a discharging resistor. The base of the transistor is electrically connected to the output terminal of the comparator circuit. The first capacitor and the second capacitor are both electrically connected between the collector and emitter of the transistor. The charging resistor is electrically connected between the collector of the transistor and the isolation circuit. The discharging resistor is electrically connected between the emitter of the transistor and ground.

6. The signal transmission circuit as described in claim 5, characterized in that, The isolation circuit includes a digital isolation chip, an input resistor, and a filter capacitor; The input resistor is electrically connected to the input terminal of the digital isolation chip, and the filter capacitor is electrically connected between the power supply terminal of the digital isolation chip and ground.

7. The signal transmission circuit as described in claim 6, characterized in that, The reference voltage satisfies the following relationship: Among them, V ref R1 represents the reference voltage, R2 represents the resistance of the first feedback resistor, R3 represents the resistance of the second feedback resistor, and U1 represents the power supply voltage.

8. The signal transmission circuit as described in claim 6, characterized in that, The input signal frequency of the digital isolation chip satisfies the following relationship: Where f represents the input signal frequency, R NTC C1 represents the resistance value of the thermistor, and C2 represents the capacitance value of the charging capacitor. V ref Indicates the reference voltage, V C1 V represents the voltage after the charging capacitor has discharged, and C2 represents the capacitance of the discharging capacitor. C2 This represents the voltage after the capacitor has discharged, V. th This indicates the threshold voltage of the transistor.

9. An electronic device, characterized in that, It includes the device body and the signal transmission circuit as described in any one of claims 1 to 8.

10. A control system, characterized in that, It includes a host computer and the electronic device as described in claim 9.

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