Surface thermionic ionization magnetic flow controller magnetic field strength measuring device
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BEIJING HANGUANG XINYUAN TECHNOLOGY CO LTD
- Filing Date
- 2025-08-12
- Publication Date
- 2026-07-21
Smart Images
Figure CN224536165U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of magnetic field monitoring technology, and more specifically, to a magnetic field strength measuring device for a surface thermal ionization magnetofluid controller. Background Technology
[0002] Surface thermal ionization magnetohydrodynamic (MHD) controllers are devices that utilize surface thermal ionization to control fluid flow, based on the principles of magnetohydrodynamics. They have potential applications in aerospace, shipbuilding, and other fields. When an aircraft flies at hypersonic speeds through the atmosphere or a spacecraft re-enters the atmosphere, the friction between the airflow and the object's surface generates high temperatures, causing thermal ionization of the gas and forming plasma. When an external magnetic field is applied, according to MHD principles, the charged particles in the plasma experience a Lorentz force. By controlling the strength, direction, and distribution of the magnetic field, the magnitude and direction of the Lorentz force can be altered, thereby controlling the airflow near the object's surface, such as changing the shock wave position and adjusting the boundary layer state. By controlling the interaction between the shock wave and the boundary layer, boundary layer separation can be prevented, reducing drag and thermal load, and improving the aerodynamic performance and thermal protection capabilities of the aircraft.
[0003] Therefore, the magnetic field strength needs to be monitored during the use of the surface thermal ionization magnetohydrodynamic controller. However, the measurement of magnetic field strength is affected by the ambient temperature, which causes the measured value to deviate from the true value, thus affecting the control accuracy of the magnetohydrodynamic controller. Utility Model Content
[0004] The problem this invention aims to solve is that when monitoring magnetic field strength, the measurement is affected by the ambient temperature, resulting in a deviation between the measured value and the true value.
[0005] To address the aforementioned issues, this invention provides a magnetic field strength measuring device for a surface thermal ionization magnetofluid controller, comprising a magnetic field strength sensor unit, a Hall amplifier circuit, a constant current source circuit, a thermistor power supply circuit, a temperature-controlled heat release current control circuit, and a temperature controller.
[0006] The magnetic field strength sensor unit includes a Hall device, a resistor assembly, and a thermistor;
[0007] The power supply terminal of the Hall device is connected to the output terminal of the constant current source circuit, the output terminal of the Hall device is connected to the input terminal of the Hall amplifier circuit, and the ground terminal of the Hall device is grounded.
[0008] One end of the resistor assembly is connected to the first power supply, and the other end of the resistor assembly is connected to one end of the temperature-controlled heat release current control circuit.
[0009] One end of the thermistor is connected to the thermistor power supply circuit, and the other end of the thermistor is connected to the input terminal of the temperature controller; the output terminal of the temperature controller is connected to the other end of the temperature control heat release current control circuit.
[0010] Optionally, the thermistor power supply circuit includes a seventh resistor, a ninth resistor, a first Zener diode, and a second capacitor. One end of the seventh resistor is connected to the positive terminal of the second power supply. The other end of the seventh resistor, one end of the ninth resistor, and one end of the second capacitor are all connected to the negative terminal of the first Zener diode. The other end of the ninth resistor is connected to the other end of the thermistor and the input terminal of the temperature controller, respectively. The other end of the second capacitor, the positive terminal of the first Zener diode, and one end of the thermistor are connected to each other and grounded.
[0011] Optionally, the temperature-controlled heat release current control circuit includes a first transistor, a first capacitor, a third amplifier, and an eighth resistor; the collector of the first transistor is connected to the other end of the resistor assembly, the emitter of the first transistor is connected to one end of the eighth resistor and the negative input terminal of the third amplifier, the other end of the eighth resistor is grounded, the base of the first transistor is connected to one end of the first capacitor and the output terminal of the third amplifier, the other end of the first capacitor is connected to the positive input terminal of the third amplifier and the output terminal of the temperature controller, and the positive and negative power supply terminals of the third amplifier are respectively connected to the positive and negative terminals of the second power supply.
[0012] Optionally, the resistor assembly includes a plurality of resistors connected in series.
[0013] Optionally, the Hall amplifier circuit includes a second resistor, a third resistor, and a second amplifier. One end of the second resistor is connected to the output terminal of the Hall device, and the other end of the second resistor is connected to the negative input terminal of the second amplifier and one end of the third resistor, respectively. The other end of the third resistor is connected to the output terminal of the second amplifier, and the output terminal of the second amplifier outputs an amplified electromagnetic intensity voltage signal. The ground terminal of the Hall device is connected to and grounded to the positive input terminal of the second amplifier. The positive power supply terminal and the negative power supply terminal of the second amplifier are respectively connected to the positive and negative terminals of the second power supply.
[0014] Optionally, the constant current source circuit includes a second transistor, a first amplifier, a first resistor, a fourth resistor, and a second Zener diode. The collector of the second transistor is connected to the power supply terminal of the Hall effect device. The emitter of the second transistor is connected to the negative input terminal of the first amplifier and one end of the fourth resistor, respectively. The base of the second transistor is connected to the output terminal of the first amplifier. The other end of the fourth resistor is connected to the positive power supply terminal of the first amplifier, the negative terminal of the second Zener diode, and the positive terminal of the second power supply, respectively. The positive terminal of the second Zener diode is connected to the positive input terminal of the first amplifier and one end of the first resistor, respectively. The other end of the first resistor is grounded. The negative power supply terminal of the first amplifier is connected to the negative terminal of the second power supply.
[0015] This invention provides a magnetic field strength measuring device for a surface thermal ionization magnetofluid controller. Compared with the prior art, it has the following advantages:
[0016] The magnetic field strength sensor unit is placed in a magnetic field. The Hall effect device can induce a voltage in the magnetic field, and this induced voltage has a linear relationship with the magnetic field strength. Therefore, the magnetic field strength can be determined by measuring the induced voltage of the Hall effect device. Since the Hall effect device is sensitive to temperature, a constant temperature control strategy is used to ensure stable monitoring of the magnetic field. The resistor in the resistive component is a power resistor used to release heat energy. A larger current flowing through it results in a larger heat generation, which can heat the area around the Hall effect device. The thermistor is used to provide real-time feedback on the temperature within the magnetic field strength sensor unit. The thermistor is connected to a thermistor power supply circuit, which provides a stable reference voltage. When the temperature rises, the thermistor resistance decreases, and the ADC voltage value fed back to the temperature controller decreases; when the temperature decreases, the thermistor resistance increases, and the ADC voltage value fed back to the temperature controller increases. The temperature controller analyzes the real-time temperature value using its internal analysis methods, compares it with the set constant temperature control temperature, and adjusts the output DAC value accordingly. It also changes the current on the resistor component through the temperature control heat dissipation current control circuit, thereby adjusting the heat dissipation of the resistor component and maintaining the ambient temperature around the Hall device at a constant temperature. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1A schematic diagram of the structure of a magnetic field strength measuring device for a surface thermal ionization magnetofluid controller provided in this embodiment of the present invention;
[0019] Figure 2 An enlarged schematic diagram of the magnetic field strength sensor unit provided in an embodiment of this utility model;
[0020] Figure 3 A partial structural enlarged schematic diagram of a magnetic field strength measuring device for a surface thermal ionization magnetofluid controller provided in this embodiment of the present invention;
[0021] Figure 4 An enlarged schematic diagram of the temperature control heat release current control circuit and temperature controller provided in the embodiments of this utility model. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0023] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.
[0024] like Figure 1 and Figure 2 As shown in the embodiment of this application, a magnetic field strength measuring device for a surface thermal ionization magnetofluid controller includes a magnetic field strength sensor unit, a Hall amplifier circuit, a constant current source circuit, a thermistor power supply circuit, a temperature control heat release current control circuit, and a temperature controller MCU.
[0025] The magnetic field strength sensor unit includes a Hall device U1, a resistor assembly, and a thermistor RTC;
[0026] The power supply terminal of the Hall device U1 is connected to the output terminal of the constant current source circuit, the output terminal of the Hall device U1 is connected to the input terminal of the Hall amplifier circuit, and the ground terminal of the Hall device U1 is grounded.
[0027] One end of the resistor assembly is connected to the first power supply (24V), and the other end of the resistor assembly is connected to one end of the temperature-controlled heat release current control circuit.
[0028] One end of the thermistor RTC is connected to the thermistor power supply circuit, and the other end of the thermistor RTC is connected to the input terminal of the temperature controller MCU; the output terminal of the temperature controller MCU is connected to the other end of the temperature control heat release current control circuit.
[0029] Specifically, the resistor assembly includes multiple resistors connected in series, for example... Figure 2 The fifth resistor R5 and the sixth resistor R6 are connected in series to form a resistor assembly. Multiple components in the magnetic field strength sensor unit are connected to other circuits via interfaces J1 and J2. The Hall effect device U1 can be a gallium arsenide Hall effect device. Furthermore, the resistor assembly, thermistor RTC, and Hall effect device U1 can be designed to be mounted on a single PCB board, encased in an appropriate amount of insulation material, and fixed within a 20mm wide, 55mm long, and 4mm thick (optimal thickness at the location of Hall effect device U1) housing, horizontally fixed in the magnetic field to be measured by a bracket. The constant temperature control setting is typically 40 degrees Celsius to ensure that the Hall effect device U1 operates at a constant temperature of 40 degrees Celsius, unaffected by external temperature changes.
[0030] In this embodiment, the magnetic field strength sensor unit is placed in a magnetic field. The Hall device U1 can sense an induced voltage in the magnetic field, which has a linear relationship with the magnetic field strength. Therefore, the magnetic field strength can be determined by measuring the induced voltage of the Hall device U1. Since the Hall device U1 is sensitive to temperature, a constant temperature control strategy is adopted to ensure stable monitoring of the magnetic field. The resistor in the resistor assembly is a power resistor used to release heat energy. A larger current results in a larger heat generation, which can heat the area around the Hall device U1. The thermistor RTC is used to provide real-time feedback on the temperature within the magnetic field strength sensor unit. The thermistor RTC is connected to a thermistor power supply circuit, which provides a stable reference voltage. When the temperature rises, the resistance of the thermistor RTC decreases, and the ADC voltage value fed back to the temperature controller MCU from the other end of the thermistor RTC decreases; when the temperature decreases, the resistance of the thermistor RTC increases, and the ADC voltage value fed back to the temperature controller MCU increases. The temperature controller MCU (model STM32F051) analyzes the real-time temperature value using its internal analysis methods, compares it with the set constant temperature control temperature, and adjusts the output DAC value accordingly. It also changes the current on the resistor component through the temperature control heat dissipation current control circuit, thereby adjusting the heat dissipation of the resistor component and keeping the ambient temperature around the Hall device U1 at a constant temperature.
[0031] In optional embodiments of this utility model, such as Figure 3As shown, the thermistor power supply circuit includes a seventh resistor R7, a ninth resistor R9, a first Zener diode U6, and a second capacitor C2. One end of the seventh resistor R7 is connected to the positive terminal of the second power supply. The other end of the seventh resistor R7, one end of the ninth resistor R9, and one end of the second capacitor C2 are all connected to the negative terminal of the first Zener diode U6. The other end of the ninth resistor R9 is connected to the other end of the thermistor RTC and the input terminal of the temperature controller MCU. The other end of the second capacitor C2, the positive terminal of the first Zener diode U6, and one end of the thermistor RTC are connected to each other and grounded.
[0032] In this embodiment, a 2.5V reference voltage is generated by the first Zener diode U6 to power the ninth resistor R9 and the thermistor RTC. Since the resistance of the thermistor RTC changes with temperature, the magnitude of the voltage signal collected between the thermistor RTC and the ninth resistor R9 also changes accordingly. The collected voltage signal is fed back to the temperature controller MCU. The temperature controller MCU can analyze the temperature condition inside the magnetic field strength sensor unit based on the collected voltage signal, and thus adjust the output DAC signal in a timely manner for temperature control.
[0033] In optional embodiments of this utility model, such as Figure 4 As shown, the temperature-controlled heat dissipation current control circuit includes a first transistor N1, a first capacitor C1, a third amplifier U5, and an eighth resistor R8. The collector of the first transistor N1 is connected to the other end of the resistor assembly. The emitter of the first transistor N1 is connected to one end of the eighth resistor R8 and the negative input terminal of the third amplifier U5, respectively. The other end of the eighth resistor R8 is grounded. The base of the first transistor N1 is connected to one end of the first capacitor C1 and the output terminal of the third amplifier U5, respectively. The other end of the first capacitor C1 is connected to the positive input terminal of the third amplifier U5 and the output terminal of the temperature controller MCU, respectively. The positive and negative power supply terminals of the third amplifier U5 are respectively connected to the positive and negative terminals of the second power supply.
[0034] In this embodiment, the temperature controller MCU measures and analyzes the temperature value using its internal ADC component. If the temperature value is higher than the set constant temperature control temperature, the PID algorithm is used to control and reduce the DAC value, thereby reducing the heating current and lowering the temperature. If the temperature value is lower than the set constant temperature control temperature, the PID algorithm is used to control and increase the DAC value, thereby increasing the heating current and raising the temperature. After PID control, the temperature will be maintained at the set constant temperature control temperature, achieving the purpose of constant temperature.
[0035] The principle of controlling the heating current through the DAC value is as follows. Assuming the initial state is zero, i.e., DAC voltage = 0, there is no current output, and the sampling voltage of the eighth resistor R8 is also zero. If the DAC is set to 0.5V at the instant, the voltage difference between the two input terminals (corresponding to pins 2 and 3) of the third amplifier U5 is 0.5V. Due to the amplification effect of the third amplifier U5, the voltage at its output terminal starts to rise from 0V. When the output voltage exceeds 0.2V, the first transistor N1 conducts, and current flows through the sampling resistor R8, gradually increasing the sampling voltage. When the sampling voltage rises to close to 0.5V, the current in the resistor component remains stable. At this time, the voltage difference between the two input terminals of the third amplifier U5 approaches 0V, the output voltage at the output terminal decreases, the first transistor N1 turns off, the circuit containing the resistor component is disconnected, and the sampling voltage of the eighth resistor R8 also gradually decreases. When the difference between the sampling voltage and the DAC output by the temperature controller MCU increases, the output voltage at the output terminal rises again, causing the first transistor N1 to conduct again. This process repeats, allowing current to flow through the resistor component, periodically dissipating heat, and maintaining a constant temperature around the Hall device U1. When the DAC increases, the output voltage of the third amplifier U5 increases, which will increase the collector current (i.e., the current on the resistor component increases), and vice versa.
[0036] In optional embodiments of this utility model, such as Figure 3 As shown, the Hall amplifier circuit includes a second resistor R2, a third resistor R3, and a second amplifier U4. One end of the second resistor R2 is connected to the output terminal of the Hall device U1, and the other end of the second resistor R2 is connected to the negative input terminal of the second amplifier U4 and one end of the third resistor R3. The other end of the third resistor R3 is connected to the output terminal of the second amplifier U4, and the output terminal of the second amplifier U4 outputs an amplified electromagnetic intensity voltage signal. The ground terminal of the Hall device U1 is connected to and grounded to the positive input terminal of the second amplifier U4. The positive power supply terminal and the negative power supply terminal of the second amplifier U4 are respectively connected to the positive and negative terminals of the second power supply.
[0037] In this embodiment, the Hall effect device U1, powered by a constant current source circuit, generates a weak voltage signal when it detects a magnetic field. The stronger the magnetic field, the larger the voltage signal. Approximately, a magnetic field strength of 0.3T induces a voltage signal of 0.2V. This signal is amplified and output by the second amplifier U4 to obtain a voltage signal reflecting the magnetic field strength. By selecting a suitable third resistor R3 (i.e., the feedback resistor), the amplification factor can be adjusted. Using a fixed-value resistor results in low temperature drift and stable reliability. In practice, a suitable R3 value is chosen so that the second amplifier U4 outputs 10V under a 1 Tesla magnetic field.
[0038] In optional embodiments of this utility model, such as Figure 3As shown, the constant current source circuit includes a second transistor P1, a first amplifier U3, a first resistor R1, a fourth resistor R4, and a second Zener diode U2. The collector of the second transistor P1 is connected to the power supply terminal of the Hall effect device U1. The emitter of the second transistor P1 is connected to the negative input terminal of the first amplifier U3 and one end of the fourth resistor R4. The base of the second transistor P1 is connected to the output terminal of the first amplifier U3. The other end of the fourth resistor R4 is connected to the positive power supply terminal of the first amplifier U3, the negative terminal of the second Zener diode U2, and the positive terminal of the second power supply. The positive terminal of the second Zener diode U2 is connected to the positive input terminal of the first amplifier U3 and one end of the first resistor R1. The other end of the first resistor R1 is grounded. The negative power supply terminal of the first amplifier U3 is connected to the negative terminal of the second power supply.
[0039] In this embodiment, the Hall device U1 is powered by both constant voltage and constant current. Since the constant current method has lower temperature drift and higher measurement accuracy, it is chosen to power the Hall device U1. The second Zener diode U2 provides a constant voltage source with a voltage difference of 5V, and the first amplifier U3 uses open-loop control. Initially, the voltage difference at the input terminals of the first amplifier U3 is 5V, guaranteed by the second Zener diode U2. Because the negative input voltage of the first amplifier U3 is higher than the positive input voltage, the output is negative, the second transistor P1 conducts, causing the current flowing through the fourth resistor R4 to continuously increase. When the current increases to 5 mA, the voltage difference between the two input terminals of the first amplifier U3 becomes 0, and the current reaches a stable output.
[0040] In summary, compared with existing technologies, it has the following beneficial effects:
[0041] 1. Measure the magnetic field strength. The magnitude of the magnetic field strength is represented by an analog voltage value through Hall effect device U1 and second amplifier U4, and the magnetic field strength is quickly responded to.
[0042] 2. The Hall device U1 adopts a constant temperature control strategy to eliminate the error caused by changes in ambient temperature in the magnetic field strength measurement.
[0043] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0044] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. A magnetic field strength measuring device for a surface thermal ionization magnetofluid controller, characterized in that, It includes a magnetic field strength sensor unit, a Hall amplifier circuit, a constant current source circuit, a thermistor power supply circuit, a temperature control and heat release current control circuit, and a temperature controller. The magnetic field strength sensor unit includes a Hall device, a resistor assembly, and a thermistor; The power supply terminal of the Hall device is connected to the output terminal of the constant current source circuit, the output terminal of the Hall device is connected to the input terminal of the Hall amplifier circuit, and the ground terminal of the Hall device is grounded. One end of the resistor assembly is connected to the first power supply, and the other end of the resistor assembly is connected to one end of the temperature-controlled heat release current control circuit. One end of the thermistor is connected to the thermistor power supply circuit, and the other end of the thermistor is connected to the input terminal of the temperature controller; the output terminal of the temperature controller is connected to the other end of the temperature control heat release current control circuit.
2. The magnetic field strength measuring device for a surface thermal ionization magnetofluid controller as described in claim 1, characterized in that, The thermistor power supply circuit includes a seventh resistor, a ninth resistor, a first Zener diode, and a second capacitor. One end of the seventh resistor is connected to the positive terminal of the second power supply. The other end of the seventh resistor, one end of the ninth resistor, and one end of the second capacitor are all connected to the negative terminal of the first Zener diode. The other end of the ninth resistor is connected to the other end of the thermistor and the input terminal of the temperature controller, respectively. The other end of the second capacitor, the positive terminal of the first Zener diode, and one end of the thermistor are connected to each other and grounded.
3. The magnetic field strength measuring device for a surface thermal ionization magnetofluid controller as described in claim 1, characterized in that, The temperature-controlled heat release current control circuit includes a first transistor, a first capacitor, a third amplifier, and an eighth resistor. The collector of the first transistor is connected to the other end of the resistor assembly. The emitter of the first transistor is connected to one end of the eighth resistor and the negative input terminal of the third amplifier, respectively. The other end of the eighth resistor is grounded. The base of the first transistor is connected to one end of the first capacitor and the output terminal of the third amplifier, respectively. The other end of the first capacitor is connected to the positive input terminal of the third amplifier and the output terminal of the temperature controller, respectively. The positive and negative power supply terminals of the third amplifier are connected to the positive and negative terminals of the second power supply, respectively.
4. The magnetic field strength measuring device for a surface thermal ionization magnetofluid controller as described in claim 1, characterized in that, The resistor assembly includes multiple resistors connected in series.
5. The magnetic field strength measuring device for a surface thermal ionization magnetofluid controller as described in claim 1, characterized in that, The Hall amplifier circuit includes a second resistor, a third resistor, and a second amplifier. One end of the second resistor is connected to the output terminal of the Hall device, and the other end of the second resistor is connected to the negative input terminal of the second amplifier and one end of the third resistor. The other end of the third resistor is connected to the output terminal of the second amplifier, and the output terminal of the second amplifier outputs an amplified electromagnetic intensity voltage signal. The ground terminal of the Hall device is connected to and grounded to the positive input terminal of the second amplifier. The positive power supply terminal and the negative power supply terminal of the second amplifier are respectively connected to the positive and negative terminals of the second power supply.
6. The magnetic field strength measuring device for a surface thermal ionization magnetofluid controller as described in any one of claims 1-5, characterized in that, The constant current source circuit includes a second transistor, a first amplifier, a first resistor, a fourth resistor, and a second Zener diode. The collector of the second transistor is connected to the power supply terminal of the Hall effect device. The emitter of the second transistor is connected to the negative input terminal of the first amplifier and one end of the fourth resistor. The base of the second transistor is connected to the output terminal of the first amplifier. The other end of the fourth resistor is connected to the positive power supply terminal of the first amplifier, the negative terminal of the second Zener diode, and the positive terminal of the second power supply. The anode of the second Zener diode is connected to the positive input terminal of the first amplifier and one end of the first resistor. The other end of the first resistor is grounded. The negative power supply terminal of the first amplifier is connected to the negative terminal of the second power supply.