A medical nuclear magnetic resonance radio frequency power amplifier equipment test discharging device

Abstract

The application belongs to the technical field of medical equipment testing, and specifically discloses a medical nuclear magnetic resonance radio frequency power amplifier equipment test discharging device, which comprises a rapid discharging module connected in parallel on an external DC power supply circuit of the equipment, a voltage detection unit is used to monitor the power supply voltage in real time, and the monitoring result is converted into an electric signal and output to a load control unit; the load control unit dynamically adjusts the discharging load resistance value according to the voltage change, so that the discharging process maintains constant current characteristics; a discharging switch circuit controls the on-off state of a high-power device through a small signal, and determines the opening and closing of the discharging function; and a display module is used to feed back the discharging state and power supply index information in real time. Through the cooperative work of the above modules, the discharging time of the energy storage capacitor is shortened, and the production test efficiency is improved. The application aims to solve the problem of slow discharging of the energy storage capacitor in the production test process of the existing medical nuclear magnetic resonance radio frequency power amplifier.

Description

Technical Field

[0001] This invention relates to the field of medical device testing technology, specifically to a testing discharge device for medical nuclear magnetic resonance radio frequency power amplifier equipment. Background Technology

[0002] In the field of medical equipment, medical magnetic resonance imaging (MRI) technology plays a crucial role, providing key support for disease diagnosis and research. Among its components, the radio frequency (RF) power amplifier is a key component of MRI equipment, typically with a high output power, ranging from several kW to tens of kW, to meet the needs of specific scans. For example, a common 3T RFM power amplifier module has an RF power amplifier output of 18kW. To meet the demands of high-power RF pulses and their instantaneous high current, the power supply section of existing medical MRI RF power amplifiers is equipped with large energy storage capacitors. These capacitors store a significant amount of electrical energy during equipment operation to ensure sufficient current is available at the moment of RF pulse transmission.

[0003] However, due to limitations in cost and size, the discharge circuitry built into the product has a relatively small discharge current. During production testing, after each power-off, the energy storage capacitor discharges slowly, requiring operators to wait a considerable amount of time until it is fully discharged before proceeding to the next stage. For example, in some production testing processes, waiting several minutes or even longer after power-off may be necessary, significantly impacting production efficiency and increasing production cycles and costs. This prolonged waiting time for discharge is particularly problematic in large-scale production and frequent testing scenarios, significantly affecting overall production efficiency.

[0004] Furthermore, the discharge process of energy storage capacitors lacks dynamic adjustment capabilities, resulting in insufficient matching between discharge rate and voltage changes, further prolonging the discharge time. Meanwhile, existing discharge control methods typically rely on the simple circuit design of the equipment itself, making it difficult to flexibly adapt to different testing requirements or emergency operation scenarios. Moreover, in actual production environments, if manual intervention in the discharge process is required, the complexity of the operation or response delay may affect the smoothness of the overall process.

[0005] Ultimately, the limitations of energy storage capacitor discharge efficiency are not only reflected in time costs but may also have potential impacts on the safety and stability of the equipment. For example, during rapid switching operations under high voltage conditions, if the discharge process is not completed in time, residual energy may cause unexpected risks. This comprehensive issue permeates the entire process from equipment design and production testing to practical application, involving complex interactions between circuit design, dynamic adjustment, operational flexibility, and safety, directly affecting the production efficiency and reliability of medical MRI equipment. Summary of the Invention

[0006] This invention provides a testing and discharge device for medical nuclear magnetic resonance radio frequency power amplifier equipment, aiming to solve the problem of slow discharge of energy storage capacitors during the production and testing of existing medical nuclear magnetic resonance radio frequency power amplifiers.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A testing discharge device for a medical MRI radio frequency power amplifier includes: a fast discharge module connected in parallel to the external DC power supply line of the device; a voltage detection unit that monitors the power supply voltage in real time and converts the monitoring results into an electrical signal output to a load control unit; a load control unit that dynamically adjusts the discharge load resistance value according to voltage changes to maintain a constant current characteristic during the discharge process; a discharge switch circuit that controls the on / off state of high-power devices through a small signal to determine the activation and deactivation of the discharge function; and a display module that provides real-time feedback on the discharge status and power supply indicators. Through the coordinated operation of these modules, the discharge time of the energy storage capacitor is shortened, improving production testing efficiency.

[0008] In one aspect of this disclosure, the fast discharge module connected in parallel to the external DC power supply line of the device includes: the fast discharge module is connected to the positive and negative terminals of the device's DC power supply line through two metal conductor terminals respectively, forming a parallel circuit structure; the metal conductor terminals are made of a high conductivity material, and their surfaces are treated with anti-oxidation to reduce contact resistance; the fast discharge module has independent discharge interface, discharge enable interface, and power supply interface, and the interfaces are isolated from each other to avoid electrical interference; the discharge interface is connected to the positive and negative terminals of the energy storage capacitor through wires to ensure low impedance characteristics of the discharge path; the discharge enable interface receives external control signals to trigger the start or stop of the discharge function; and the power supply interface provides a stable power input for the voltage detection unit and the load control unit.

[0009] In one aspect of this disclosure, the step of using a voltage detection unit to monitor the power supply voltage in real time and converting the monitoring result into an electrical signal output to the load control unit includes: the voltage detection unit sampling the power supply voltage through a voltage divider sampling resistor network to obtain a sampled voltage proportional to the power supply voltage; the sampled voltage being amplified and filtered by an operational amplifier to generate a stable analog signal; the analog signal being converted into a digital signal by an analog-to-digital converter and transmitted to the load control unit; the load control unit determining the rate of decrease of the power supply voltage based on the changing trend of the digital signal and adjusting the discharge load resistance value accordingly; if the power supply voltage is high, the load control unit selecting a larger resistance value to limit the initial discharge current; as the power supply voltage gradually decreases, the load control unit gradually switches to a smaller resistance value to maintain the constant characteristics of the discharge current.

[0010] In one aspect of this disclosure, the step of dynamically adjusting the discharge load resistance value according to voltage changes to maintain a constant current characteristic during the discharge process includes: the load control unit connecting multiple groups of power resistors through multiple controllable switching devices, with the resistance value of each group of power resistors decreasing according to a preset rule; the on / off state of the controllable switching devices being determined by the load control unit based on feedback signals from the voltage detection unit; when the power supply voltage is at a high level, the load control unit only closes the controllable switching devices connected to high-resistance resistors to limit the initial peak value of the discharge current; as the power supply voltage decreases, the load control unit sequentially closes the controllable switching devices connected to low-resistance resistors to gradually reduce the total resistance value; by dynamically adjusting the total resistance value, the load control unit maintains the discharge current within a preset range, thereby achieving a constant current discharge effect.

[0011] In one aspect of this disclosure, the discharge switch circuit determines the activation and deactivation of the discharge function by controlling the on / off state of a high-power device with a small signal. This includes: the core device of the discharge switch circuit is a high-power MOSFET or relay, whose control terminal receives a small signal input from the discharge enable interface; when the discharge enable interface receives an external trigger signal, the small signal input drives the high-power device into a conducting state, forming a complete discharge circuit; if the external trigger signal disappears, the small signal input stops, the high-power device enters a cut-off state, and the discharge circuit is cut off; the discharge switch circuit also includes protective components, such as transient voltage suppression diodes and fuses, to prevent damage to the circuit from overvoltage or overcurrent; the protective components are connected in series with the high-power device to ensure rapid circuit disconnection under abnormal conditions.

[0012] In one aspect of this disclosure, the step of the display module providing real-time feedback of discharge status and power supply indicators includes: the display module being connected to the load control unit and the voltage detection unit via a data bus to acquire real-time parameters such as discharge current, power supply voltage, and discharge time; the display module integrating a microcontroller for processing and formatting the received data; the processed data being visualized through an LCD screen or LED indicator lights; the LCD screen employing a multi-line display design to display the current power supply voltage value, discharge current value, and remaining discharge time; the LED indicator lights using different colors to represent the discharge status, such as green indicating discharge completion and red indicating discharge in progress; the display module also supports an alarm function, emitting an alarm sound via a buzzer when abnormal parameters are detected.

[0013] In one aspect of this disclosure, the response mechanism of the fast discharge module to external control signals includes: the discharge enable interface supports two control modes, namely automatic mode and manual mode; in automatic mode, the discharge enable interface receives a trigger from the device's electrical control signal and automatically starts the discharge function; in manual mode, the operator triggers the discharge enable interface by pressing a manual button to start the discharge function; the discharge enable interface is internally equipped with a signal conditioning circuit for shaping and debouncing the input signal; the signal conditioning circuit uses a Schmitt trigger to achieve edge detection of the signal, ensuring the stability and reliability of the trigger signal; the discharge enable interface also has a status feedback function, displaying the current control mode and trigger status through indicator lights.

[0014] In one aspect of this disclosure, the safety design of the fast discharge module includes: an over-temperature protection circuit internally configured to monitor the operating temperature of high-power devices; the over-temperature protection circuit acquires a temperature signal through a thermistor and converts it into a voltage signal; the voltage signal is compared with a preset threshold by a comparator, and if the threshold is exceeded, a protection action is triggered; the protection action includes cutting off the control signal of the discharge switch circuit to stop the discharge process; the fast discharge module also includes an overcurrent protection circuit, which monitors the current value of the discharge circuit through a current transformer; if the detected current exceeds a preset upper limit, the overcurrent protection circuit immediately cuts off the discharge circuit to prevent damage to circuit components.

[0015] In one aspect of this disclosure, the installation and debugging method of the fast discharge module includes: the fast discharge module is installed on the side of the equipment housing by a fixing bracket made of high-strength aluminum alloy; the fixing bracket is connected to the equipment housing by bolts, and the tightening torque of the bolts must meet a preset standard to ensure installation firmness; the connection between the metal conductor terminals of the fast discharge module and the DC power supply line of the equipment is made by crimping, and the crimping tool must meet the specified pressure requirements; after installation, the performance of the fast discharge module is debugged by a special testing instrument, including measuring the stability of the discharge current, the accuracy of the discharge time, and the reliability of the electrical connection of each interface; during the debugging process, the actual values ​​of each parameter need to be recorded and compared with the design values ​​to ensure that the module performance meets the requirements.

[0016] In one aspect of this disclosure, the maintenance and troubleshooting method for the fast discharge module includes: periodically checking whether the metal conductor terminals of the fast discharge module are oxidized or loose, and if problems are found, cleaning or re-crimping should be done in a timely manner; measuring the resistance value of the discharge circuit with a multimeter to determine whether there is an open circuit or short circuit fault; if an abnormal discharge current is found, checking whether the controllable switching device of the load control unit is working properly; for display module faults, troubleshooting can be done by replacing the LCD screen or LED indicator; during the maintenance process, the results of each inspection should be recorded and a fault file should be established for subsequent analysis and improvement.

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention integrates a rapid discharge module, a voltage detection unit, and a dynamic load control unit to achieve rapid and controllable discharge of the energy storage capacitor in medical MRI radio frequency power amplifier equipment. This effectively reduces the original discharge waiting time of several minutes to within tens of seconds, significantly improving production and testing efficiency. Its intelligent load adjustment mechanism maintains constant current characteristics during the discharge process, avoiding initial current surges. Combined with dual over-temperature and over-current protection and real-time status display, it enhances operational safety and visibility while also considering equipment compatibility and engineering applicability, comprehensively solving the problems of low efficiency, slow response, and insufficient safety in traditional discharge methods. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a test discharge device for a medical nuclear magnetic resonance radio frequency power amplifier according to the present invention.

[0020] Figure 2 This is a schematic diagram of the framework of the present invention.

[0021] Figure 3 This is a schematic diagram of the load control unit of the present invention. Detailed Implementation

[0022] The present invention will be further described below with reference to embodiments. These embodiments are merely some, not all, of the embodiments described. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the protection scope of the present invention.

[0023] Please see Figures 1-3 As shown in the figure, this embodiment discloses a test discharge device for medical magnetic resonance radio frequency power amplifier equipment. Its core lies in achieving rapid discharge of the energy storage capacitor through the coordinated operation of multiple modules. The specific implementation of this device is described in detail below with reference to the description in the invention summary and accompanying drawings.

[0024] The device includes a fast discharge module, a voltage detection unit, a load control unit, a discharge switch circuit, and a display module. The fast discharge module is connected to the positive and negative terminals of the device's DC power supply line via two metal conductor terminals, forming a parallel circuit structure. The metal conductor terminals are made of highly conductive material and have undergone anti-oxidation treatment to reduce contact resistance. The fast discharge module internally has independent discharge, discharge enable, and power supply interfaces, which are isolated from each other to prevent electrical interference. The discharge interface is connected to the positive and negative terminals of the energy storage capacitor via wires to ensure low impedance characteristics of the discharge path. The discharge enable interface receives external control signals to trigger the start or stop of the discharge function. The power supply interface provides a stable power input to the voltage detection unit and the load control unit.

[0025] The voltage detection unit samples the power supply voltage through a voltage divider sampling resistor network to obtain a sampled voltage proportional to the power supply voltage. The sampled voltage is amplified and filtered by an operational amplifier to generate a stable analog signal. This analog signal is converted into a digital signal by an analog-to-digital converter and transmitted to the load control unit. The load control unit determines the rate of decrease in the power supply voltage based on the trend of the digital signal and adjusts the discharge load resistor value accordingly. When the power supply voltage is high, the load control unit selects a larger resistor value to limit the initial discharge current. As the power supply voltage gradually decreases, the load control unit gradually switches to a smaller resistor value to maintain a constant discharge current.

[0026] The load control unit connects multiple groups of power resistors via various controllable switching devices, with the resistance values ​​of each group decreasing according to a preset rule. The on / off state of the controllable switching devices is determined by the load control unit based on feedback signals from the voltage detection unit. When the power supply voltage is high, the load control unit only closes the controllable switching devices connected to high-resistance resistors, limiting the initial peak value of the discharge current. As the power supply voltage decreases, the load control unit sequentially closes the controllable switching devices connected to low-resistance resistors, gradually reducing the total resistance value. By dynamically adjusting the total resistance value, the load control unit maintains the discharge current within a preset range, thereby achieving a constant current discharge effect.

[0027] The core component of the discharge switch circuit is a high-power MOSFET or relay, whose control terminal receives a small signal input from the discharge enable interface. When the discharge enable interface receives an external trigger signal, the small signal input drives the high-power device into the conducting state, forming a complete discharge circuit. If the external trigger signal disappears, the small signal input stops, the high-power device enters the cut-off state, and the discharge circuit is broken. The discharge switch circuit also includes protective components, such as transient voltage suppression diodes and fuses, to prevent damage to the circuit from overvoltage or overcurrent. The protective components are connected in series with the high-power device to ensure that the circuit can be quickly cut off in abnormal conditions.

[0028] The display module is connected to the load control unit and voltage detection unit via a data bus to acquire real-time parameters such as discharge current, power supply voltage, and discharge time. An integrated microcontroller processes and formats the received data. The processed data is then visualized via an LCD screen or LED indicators. The LCD screen uses a multi-line display design to show the current power supply voltage, discharge current, and remaining discharge time. LED indicators use different colors to represent the discharge status, such as green for complete discharge and red for in progress. The display module also supports an alarm function; when abnormal parameters are detected, an alarm sound is emitted via a buzzer.

[0029] The rapid discharge module's response mechanism to external control signals includes automatic and manual modes. In automatic mode, the discharge enable interface receives a trigger signal from the device's electrical control and automatically initiates the discharge function. In manual mode, the operator triggers the discharge enable interface by pressing a manual button to initiate the discharge function. The discharge enable interface internally incorporates a signal conditioning circuit for shaping and debouncing the input signal. This circuit uses a Schmitt trigger to detect signal edges, ensuring the stability and reliability of the trigger signal. The discharge enable interface also features status feedback, displaying the current control mode and trigger status via indicator lights.

[0030] The safety design of the fast discharge module includes over-temperature protection and over-current protection circuits. The over-temperature protection circuit collects the temperature signal through a thermistor and converts it into a voltage signal. This voltage signal is compared to a preset threshold by a comparator; if the threshold is exceeded, protection is triggered. The protection action includes cutting off the control signal to the discharge switch circuit, stopping the discharge process. The over-current protection circuit monitors the current value in the discharge circuit through a current transformer. If the detected current exceeds a preset upper limit, the over-current protection circuit immediately cuts off the discharge circuit to prevent damage to circuit components.

[0031] The installation and commissioning method of the fast discharge module includes mounting the module on the side of the equipment housing using a mounting bracket made of high-strength aluminum alloy. The bracket is connected to the housing with bolts, and the tightening torque of the bolts must meet preset standards to ensure secure installation. The connection between the metal conductor terminals of the fast discharge module and the equipment's DC power supply line is achieved using a crimping process, and the crimping tool must meet the specified pressure requirements. After installation, the performance of the fast discharge module is commissioned using specialized testing instruments, including measuring the stability of the discharge current, the accuracy of the discharge time, and the reliability of the electrical connections at each interface. During commissioning, the actual values ​​of each parameter must be recorded and compared with the design values ​​to ensure that the module performance meets the requirements.

[0032] Maintenance and troubleshooting methods for the fast discharge module include regularly checking the metal conductor terminals for oxidation or loosening; if problems are found, they should be cleaned or re-crimped promptly. The resistance of the discharge circuit should be measured with a multimeter to determine if there is an open circuit or short circuit. If abnormal discharge current is detected, the controllable switching devices of the load control unit should be checked for proper functioning. For display module faults, troubleshooting can be performed by replacing the LCD screen or LED indicator lights. During maintenance, the results of each inspection should be recorded, and a fault log should be established for subsequent analysis and improvement.

[0033] In the above embodiment, the fast discharge module is connected to the equipment's DC power supply line in parallel. A voltage detection unit monitors the power supply voltage in real time and transmits the results to the load control unit. The load control unit dynamically adjusts the discharge load resistance value based on voltage changes, maintaining a constant current characteristic during the discharge process. The discharge switch circuit controls the on / off state of high-power devices through a small signal, determining whether the discharge function is enabled or disabled. The display module provides real-time feedback on the discharge status and power supply indicators. Through the coordinated operation of these modules, the discharge time of the energy storage capacitor is significantly shortened, production testing efficiency is improved, and the safety and reliability of the equipment are enhanced.

[0034] To enable those skilled in the art to fully understand and implement this invention, the specific implementation principle of this invention is further explained below in conjunction with a specific application scenario.

[0035] During the production and testing of medical MRI radio frequency power amplifier equipment, a rapid discharge device for the energy storage capacitor is installed on the side of the equipment casing and connected to the DC power supply line via metal conductor terminals. Operators first secure the rapid discharge module to the equipment casing, ensuring the bolts of the mounting bracket are tightened to the preset torque to guarantee the module's secure installation. Subsequently, the metal conductor terminals are connected to the equipment's DC power supply line using a crimping process, ensuring the contact resistance is as low as possible to reduce energy loss and improve discharge efficiency.

[0036] After the equipment completes a test, the operator presses the manual button or waits for the equipment to automatically trigger a power-down signal. At this time, the discharge enable interface receives an external control signal. After being processed by the internal signal conditioning circuit, the signal drives the high-power MOSFET in the discharge switch circuit to enter the conducting state, forming a complete discharge loop. Simultaneously, the voltage detection unit begins real-time monitoring of the power supply voltage. The voltage signal collected by the voltage divider sampling resistor network is amplified and filtered by an operational amplifier, converted into a digital signal, and transmitted to the load control unit.

[0037] The load control unit determines the rate of decrease of the current power supply voltage based on the received digital signal and dynamically adjusts the discharge load resistance value. For example, in the initial stage, when the power supply voltage is high, the load control unit only closes the controllable switching devices connected to high-resistance resistors to limit the peak value of the initial discharge current and prevent damage to circuit components due to excessive current. As the power supply voltage gradually decreases, the load control unit sequentially closes the controllable switching devices connected to low-resistance resistors, gradually reducing the total resistance value, thereby maintaining the constant characteristics of the discharge current. This dynamic adjustment mechanism ensures the safety and stability of the discharge process while significantly shortening the discharge time.

[0038] During the discharge process, the display module acquires parameters such as discharge current, power supply voltage, and remaining discharge time in real time via the data bus and displays them visually on the LCD screen. Operators can intuitively understand the current discharge status through the display. For example, when the power supply voltage drops to a safe range, the LED indicator switches from red to green, indicating that the discharge is complete. If abnormal parameters are detected, such as excessively high discharge current or voltage fluctuations exceeding the preset range, the display module will sound an alarm via a buzzer to remind the operator to take timely action.

[0039] In addition, the fast discharge module has multiple protection functions. The over-temperature protection circuit monitors the operating temperature of high-power devices in real time using a thermistor and converts it into a voltage signal. When the temperature exceeds a preset threshold, a comparator triggers the protection action, cutting off the control signal of the discharge switch circuit and stopping the discharge process. The overcurrent protection circuit monitors the current value of the discharge circuit using a current transformer. If the detected current exceeds a preset upper limit, the discharge circuit is immediately cut off to prevent circuit components from being damaged due to overload. These protection mechanisms effectively improve the safety and reliability of the equipment.

[0040] In practical applications, the debugging and maintenance of the fast discharge module are equally crucial. After installation, operators use specialized testing instruments to debug the module's performance, including measuring the stability of the discharge current, the accuracy of the discharge time, and the reliability of the electrical connections at each interface. All parameters recorded during debugging must be compared and analyzed with the design values ​​to ensure the module's performance meets requirements. During routine maintenance, operators regularly check the metal conductor terminals for oxidation or loosening and use a multimeter to measure the resistance of the discharge circuit to determine if there are open or short circuit faults. For display module faults, troubleshooting can be performed by replacing the LCD screen or LED indicator lights. The results of each maintenance operation must be recorded and a fault file established for subsequent analysis and improvement.

[0041] Through the synergistic operation of the above steps and principles, the fast discharge module significantly shortens the discharge time of the energy storage capacitor from several minutes to tens of seconds, greatly improving production testing efficiency. Simultaneously, the module's safety and reliability are effectively guaranteed, reducing the problems of extended production cycles and increased costs caused by slow discharge. This technical solution is not only suitable for production testing scenarios of medical MRI radio frequency power amplifier equipment, but can also be extended to other high-power equipment fields requiring rapid discharge, showing broad application prospects.

[0042] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A test discharge device for medical nuclear magnetic resonance radio frequency power amplifier equipment, characterized in that, include: The fast discharge module is connected to the positive and negative terminals of the device's DC power supply line through two metal conductor terminals to form a parallel circuit structure. The fast discharge module is equipped with a discharge interface, a discharge enable interface and a power supply interface. The voltage detection unit samples the power supply voltage through a voltage divider sampling resistor network, and converts the sampled voltage into a digital signal after amplification and filtering by an operational amplifier and output to the load control unit. The load control unit dynamically adjusts the discharge load resistance value based on the digital signal output by the voltage detection unit to maintain the constant discharge current. The discharge switch circuit controls the on / off state of high-power devices through a small signal, thus determining whether the discharge function is turned on or off. The display module is used to provide real-time feedback on discharge status and power supply indicators.

2. The test discharge device for a medical nuclear magnetic resonance radio frequency power amplifier according to claim 1, characterized in that: The metal conductor terminals of the fast discharge module are made of a high conductivity material and the surface is treated with anti-oxidation. The discharge interface is connected to the positive and negative terminals of the energy storage capacitor through wires. The discharge enable interface receives external control signals to trigger the start or stop of the discharge function. The power supply interface provides power input to the voltage detection unit and the load control unit.

3. The test discharge device for a medical nuclear magnetic resonance radio frequency power amplifier according to claim 1, characterized in that: The voltage detection unit obtains a sampled voltage proportional to the power supply voltage through a voltage divider sampling resistor network. The sampled voltage is amplified and filtered by an operational amplifier to generate an analog signal. The analog signal is converted into a digital signal by an analog-to-digital converter and transmitted to the load control unit.

4. The test discharge device for a medical nuclear magnetic resonance radio frequency power amplifier according to claim 1, characterized in that: The load control unit is connected to multiple groups of power resistors through multiple controllable switching devices. The resistance values ​​of each group of power resistors are arranged in descending order according to a preset rule. The on / off state of the controllable switching devices is determined by the load control unit based on the feedback signal from the voltage detection unit.

5. The test discharge device for a medical nuclear magnetic resonance radio frequency power amplifier according to claim 4, characterized in that: When the power supply voltage is at a high level, the load control unit only closes the controllable switching device connected to the high-resistance resistor to limit the initial peak value of the discharge current. As the power supply voltage decreases, the load control unit sequentially closes the controllable switching device connected to the low-resistance resistor to gradually reduce the total resistance value.

6. The test discharge device for a medical nuclear magnetic resonance radio frequency power amplifier according to claim 1, characterized in that: The core component of the discharge switch circuit is a high-power MOSFET or a relay. Its control terminal receives a small signal input from the discharge enable interface. When the discharge enable interface receives an external trigger signal, the small signal input drives the high-power device to enter the conduction state, forming a complete discharge circuit.

7. The test discharge device for a medical nuclear magnetic resonance radio frequency power amplifier according to claim 6, characterized in that: The discharge switch circuit also includes protection components, which include transient voltage suppression diodes and fuses, and are connected in series with high-power devices.

8. The test discharge device for a medical nuclear magnetic resonance radio frequency power amplifier according to claim 1, characterized in that: The display module is connected to the load control unit and voltage detection unit via a data bus to obtain real-time discharge current, power supply voltage and discharge time parameters. The display module integrates a microcontroller for processing and formatting the received data.

9. The test discharge device for a medical nuclear magnetic resonance radio frequency power amplifier according to claim 8, characterized in that: The display module provides a visual display through an LCD screen or multi-color LED indicator. The LCD screen adopts a multi-line display design to display the current power supply voltage value, discharge current value, and remaining discharge time, respectively. The LED indicator uses different colors to indicate the discharge status.

10. The test discharge device for a medical nuclear magnetic resonance radio frequency power amplifier according to claim 1, characterized in that: The fast discharge module is equipped with an over-temperature protection circuit and an over-current protection circuit. The over-temperature protection circuit collects the temperature signal through a thermistor and converts it into a voltage signal. The voltage signal is compared with a preset threshold by a comparator. If the voltage exceeds the threshold, the control signal of the discharge switch circuit is cut off. The over-current protection circuit monitors the current value of the discharge circuit through a current transformer. If the current exceeds the preset upper limit, the discharge circuit is immediately cut off.

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