Voltage and current control circuit of magnetic therapeutic apparatus

Abstract

The utility model belongs to the field of power electronics, and particularly relates to a voltage and current control circuit of a magnetic therapeutic instrument. Comprising a voltage sampling module, a current sampling module, a signal processing module, an output control module and a power supply module. The voltage sampling module is isolated and filtered by a voltage isolation chip 107 through a divider resistance network and then is connected with an operational amplifier 1C2 of the signal processing module; the current sampling module is connected with the operational amplifier 1C1 through a sampling resistor R57 and a current isolation chip 109; the signal processing module is connected with the voltage sampling module, the current sampling module, the output control module and the power supply module through a control chip U14. In the practical application, the isolation of voltage and current signals is realized through the isolation voltage sampling chip IC7 and the isolation current sampling chip IC9, and the isolated and acquired signals are input into the feedback circuit through the in-phase adder, so that the control of the voltage and the current is realized; therefore, a high-voltage signal in the magnetic therapy instrument is converted into a low-voltage signal which can be safely measured.

Description

Technical Field

[0001] This utility model belongs to the field of power electronics technology, specifically relating to a voltage and current control circuit for a magnetic therapy device. Background Technology

[0002] In magnetic therapy devices, precise control of voltage and current output is crucial for ensuring system stability and functional reliability. To achieve precise adjustment of the output signal, a design combining feedback networks and operational amplifiers is typically employed. Feedback networks, by feeding a portion of the output signal back to the input, enable closed-loop control, thereby adjusting gain, stabilizing the signal, and improving system performance. Isolation amplifiers are widely used in high-voltage and low-voltage circuit isolation scenarios; by combining isolated sampling signals with the main control signal, they effectively reduce interference from high-voltage to low-voltage control circuits. However, relying solely on a single amplifier is insufficient to meet the demands of high-precision control; therefore, multi-stage amplification circuits and complex feedback networks are required for signal optimization.

[0003] A magnetic isolation feedback circuit, patent publication number CN108614610A, includes: a control circuit; a sampling error amplification circuit, used to sample the output voltage signal of the conversion power supply and generate an error voltage signal when the control signal of the control circuit is at a preset first level; a modulation circuit, used to modulate the error voltage signal and load it onto a high-frequency carrier; a demodulation circuit, used to demodulate the high-frequency carrier to obtain the error voltage signal; the secondary end of an isolation transformer is used to transmit the received error voltage signal to the primary end, and then to the feedback end of the control chip; a current limiting circuit, used to limit the output current of the conversion power supply within a preset range; wherein, when the control signal of the control circuit is at a preset second level, the control signal provides a stable voltage to the sampling error amplification circuit and the current limiting circuit through the isolation transformer. The above device is affected by the frequency stability of the high-frequency carrier and noise interference during modulation and demodulation, which may lead to a decrease in the accuracy of the error signal. Therefore, it is urgent for those skilled in the art to solve the above technical problems. Summary of the Invention

[0004] The technical problem to be solved by this utility model is that, in the above-mentioned prior art, when grinding and repairing burrs on a workpiece, it is impossible to repair both the front and back sides of the workpiece at the same time, and the pressure applied by the flat press table to the workpiece for a long time will damage the device.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] A voltage and current control circuit for a magnetic therapy device includes a voltage sampling module, a current sampling module, a signal processing module, an output control module, and a power supply module.

[0007] The voltage sampling module is connected to the operational amplifier 1C2 of the signal processing module after being isolated and filtered by the voltage isolation chip 107 through a voltage divider resistor network.

[0008] The current sampling module is connected to operational amplifier IC1 via sampling resistor R57 and current isolation chip 109.

[0009] The signal processing module is connected to the voltage sampling module, the current sampling module, the output control module, and the power supply module via the control chip U14.

[0010] By adopting the above technical solution, the voltage isolation chip (IC7) and current isolation chip (IC9) achieve electrical isolation between the high-voltage side and the low-voltage side, ensuring the safety of high-voltage signal sampling and processing, and avoiding potential threats from high voltage to the low-voltage side signal processing circuit and users. The current limiting control signal (ICTR) generated by the current sampling module and operational amplifier IC1 can monitor and limit the output current within a safe range in real time, further improving the safety of the equipment. The voltage sampling module and current sampling module achieve high-precision signal sampling through a series resistor network and the isolation chip, and interference is eliminated by a filtering circuit to ensure signal accuracy. (Filter capacitor...) The control circuit effectively eliminates high-frequency noise and spike interference, ensuring signal stability and reliability, and improving the quality of the operational amplifier output signal. The control signal VCTRL generated by the operational amplifier IC2 can dynamically adjust the output voltage intensity, while current limiting control is achieved through the ICTR signal to meet the operating requirements of the magnetic therapy device in complex scenarios. The circuit design integrates the user intensity signal input function, allowing users to adjust the output intensity, enhancing the usability and user experience of the device. The power module provides independent power to the high-voltage and low-voltage components through isolated power supplies, eliminating the interference of high-voltage fluctuations on the low-voltage signal processing and control chip, and ensuring the stable operation of the entire system.

[0011] Furthermore, the voltage sampling module divides the high-voltage signal through a series of resistors R28, R29, R37, R78, R87, R95, R96, R44, and R47, and inputs it to the input terminal of the voltage isolation chip IC7. The voltage isolation chip IC7 outputs the isolated low-voltage signal, which passes through capacitors C93 and C94 in the filter circuit and a series of resistors R39 and R36, and is then transmitted to the input terminal of the operational amplifier IC2 of the signal processing module.

[0012] The current sampling module acquires the current signal on the high-voltage side through the sampling resistor R57. The voltage signals at both ends are input to the input terminal of the current isolation chip IC9. The current isolation chip IC9 outputs the isolated low-voltage signal, which is directly transmitted to the input terminal of the operational amplifier IC1 of the signal processing module after passing through capacitors C106 and C108 in the filter circuit.

[0013] Furthermore, the signal processing module consists of operational amplifier IC2 and operational amplifier IC1, wherein operational amplifier IC2 receives voltage sampling signals and user intensity signals through the control circuit, generates control signal VCTRL and transmits it to the output control module;

[0014] Operational amplifier IC1 receives current sampling signals and generates current limiting control signals ICTR. The output signal is further stabilized by filtering and control circuits. The output control module is based on control chip U14. The output terminal acts on the high-voltage circuit through the load loop and is connected to the feedback network.

[0015] The power module is connected to the voltage isolation chip IC7 and current isolation chip IC9 on the high-voltage side and the operational amplifier IC1, operational amplifier IC2 and control chip U14 on the low-voltage side via isolated power supply.

[0016] Furthermore, the filtering circuit includes capacitors C93 and C94 connected in parallel to the output of voltage isolation chip IC7; capacitors C106 and C108 connected in parallel to the output of current isolation chip IC9; capacitor C95 connected in series to the input of operational amplifier IC2 in the signal processing module; and capacitor C96 connected in parallel to the output of operational amplifier IC2.

[0017] By adopting the above technical solution, capacitors C93 and C94 at the output of voltage isolation chip IC7, and capacitors C106 and C108 at the output of current isolation chip IC9, are connected in parallel to form a low-pass filter. This effectively eliminates high-frequency noise and transient interference, outputting stable and smooth voltage and current signals. The filtered signal is cleaner, providing a reliable foundation for subsequent operational amplifier processing. Capacitors can absorb high-frequency spikes and transient voltages, reducing the impact of external electromagnetic interference (EMI) on the circuit and improving the overall circuit's anti-interference capability. Especially under high-voltage environments, the filter capacitors can reduce high-frequency waves. To mitigate interference with sensitive components and ensure stable system operation, capacitor C95 connected in series at the input of operational amplifier IC2 filters the input signal, eliminating DC offset and noise signals to ensure the accuracy of the input signal. This is particularly important for operations involving superimposed user strength signals (VCTRL) and voltage sampling signals, ensuring that the signal processing module outputs high-precision control signals. Capacitor C96 connected in parallel at the output of operational amplifier IC2 smooths the control signal VCTRL, eliminating signal fluctuations and ensuring stable output. A stable VCTRL signal is crucial for the normal operation of the output control module and the stable adjustment of the load circuit.

[0018] Furthermore, the control circuit includes resistors R38 and R43 connected in series in the path of the control signal VCTRL; one end of the control circuit is connected to the control signal VCTRL, and the other end is connected to capacitor C95 and the input terminal of operational amplifier IC2. Capacitor C95 is connected in parallel between the node of resistors R38 and R43 connected in series and the ground terminal, and capacitor C96 is connected in parallel between the output terminal of operational amplifier IC2 and the ground terminal.

[0019] By adopting the above technical solution, R38 and R43 are connected in series to form a control circuit, which limits the current and voltage of the control signal VCTRL to prevent the input signal from being too large or too strong to enter the input terminal of the operational amplifier IC2, thus avoiding performance degradation or damage due to overload. The control design ensures that the signal is transmitted within a safe range, providing reliable protection for the operational amplifier. R38 and R43 adjust the amplitude of the control signal VCTRL by voltage division, making the input signal more suitable for the processing range of subsequent circuits, avoiding nonlinear distortion or saturation caused by excessive signal. Precise signal amplitude control helps improve the accuracy of the signal processing module in generating the control signal VCTRL. Capacitor C95 is connected in parallel between the node after R38 and R43 are connected in series and the ground terminal to perform low-pass filtering on the signal, effectively removing high-frequency noise and interference components, making the signal smoother and more stable, and further improving the signal processing accuracy.

[0020] Furthermore, the voltage sampling module is connected to the non-inverting adder IC8 through the voltage isolation chip IC7. At the same time, the control signal VCTRL is transmitted to the filter capacitor C95 after being divided by the series resistors R38 and R43. The filter capacitor C95 is connected in parallel between the voltage division point of resistors R38 and R43 and the ground terminal, and is transmitted to the input terminal of the non-inverting adder IC8.

[0021] By adopting the above technical solution, IC7 isolates the high-voltage signal and outputs a low-voltage safety signal to the in-phase adder IC8, effectively isolating the high-voltage circuit from the low-voltage signal processing circuit. This avoids direct interference from the high voltage to subsequent circuits, improving the safety and reliability of the circuit. The control signal VCTRL is divided by series resistors R38 and R43 to ensure that the signal amplitude input to the in-phase adder IC8 is within an appropriate range, preventing the adder from malfunctioning or being damaged due to excessively high signal. This plays a dual role of input signal regulation and protection, helping to improve the stability of the system. C95 is connected in parallel between the voltage divider point of R38 and R43 and the ground terminal to perform low-pass filtering on the divided signal, effectively removing high-frequency noise and spike interference, making the signal smoother and more stable. After the filtered signal enters the in-phase adder IC8, it can significantly improve the signal processing accuracy and output stability.

[0022] Furthermore, the high-voltage signal input to the high-voltage sampling module is 400V-1200V. Resistors R28, R29, R37, R78, R87, R95, R96, R44, and R47 are connected in series between the high-voltage signal and the high-voltage grounding terminal. A working indicator LED1 is provided between resistor R28 and the high-voltage signal. The resistance of resistors R28, R29, R37, and R78 is 1000KΩ, the resistance of resistors R87, R95, R96, and R44 is 200KΩ-250KΩ, and the resistance of resistor R47 is 10KΩ-20KΩ.

[0023] Furthermore, the voltage isolation chip IC7 uses an AMC1311DWVR chip, the current isolation chip IC9 uses an AMC1301DWVR chip, the operational amplifier IC1 and the operational amplifier IC2 use LMV358IDR chips, and the control chip U14 uses an EG4321 chip.

[0024] Furthermore, the in-phase adder IC8 uses the LMV358IDR chip.

[0025] This utility model has the following beneficial effects:

[0026] 1. This utility model uses voltage isolation chips and current isolation chips to isolate the voltage and current signals on the high-voltage side respectively. Through circuit design such as voltage division, filtering and control, it ensures that the signal transmission on the isolated low-voltage side is safer and more reliable. The signal isolation method can effectively suppress the interference of the high-voltage circuit to the low-voltage signal processing module, and improve the anti-interference ability and operational stability of the system.

[0027] 2. This utility model, through the non-inverting addition design of the operational amplifier in the signal processing module, can accurately superimpose the voltage sampling signal and the intensity signal input by the user to generate a stable control signal VCTRL, which is then transmitted to the output control module. With the use of control and filtering circuits, the signal processing accuracy and output signal stability are significantly improved, ensuring more efficient and accurate control in the load circuit.

[0028] 3. This utility model reduces the number of components by optimizing the module design. Through the combined design of resistor voltage divider, capacitor filter and operational amplifier, it integrates multiple functions (isolation, control, filtering and superposition) into a simple circuit structure, which reduces the complexity of the circuit and the implementation cost. At the same time, it reduces the working stress of the components, extends the service life of the components, and significantly improves the overall reliability of the circuit and its engineering application value. Attached Figure Description

[0029] Figure 1 This is a circuit block diagram of the present invention;

[0030] Figure 2 This is a schematic diagram of the circuit connection of this utility model. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and specific preferred embodiments.

[0032] In the description of this utility model, it should be understood that the terms "left side," "right side," "upper part," "lower part," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. "First," "second," etc., do not indicate the importance of the components, and therefore should not be construed as a limitation of this utility model. The specific dimensions used in this embodiment are only for illustrating the technical solution and do not limit the protection scope of this utility model.

[0033] like Figure 1 and Figure 2As shown, a voltage and current control circuit for a magnetic therapy device is described in detail below with reference to embodiments to better understand this invention. The voltage sampling module divides a high-voltage signal of 400V-1200V into a low-voltage signal suitable for subsequent processing through a series of series resistors R28, R29, R37, R78, R87, R95, R96, R44, and R47.

[0034] The voltage sampling module divides the high-voltage signal and the high-voltage ground terminal through a series resistor. An indicator light LED1 is set between the resistor R28 and the high-voltage signal to indicate the working status. The voltage isolation module uses the voltage isolation chip IC7 (model AMC1311DWVR) to electrically isolate the divided high-voltage signal, avoiding direct connection between the high-voltage and low-voltage parts and ensuring circuit safety.

[0035] The signal processing module consists of operational amplifier IC2 and operational amplifier IC1. It receives the low-voltage signal from the voltage sampling module and the intensity signal input by the user. It generates a control signal VCTRL through the control circuit and transmits it to the output control module. Operational amplifier IC1 receives the current sampling signal, generates the current limiting control signal ICTR, and stabilizes the output signal through the filtering circuit and the control circuit.

[0036] The current sampling module acquires the high-voltage side current signal through sampling resistor R57. This signal is converted into a low-voltage signal by the current isolation chip IC9 (AMC1301DWVR) and then transmitted to the operational amplifier IC1 in the signal processing module. The output control module, centered on control chip U14, receives the control signal VCTRL and the current-limiting control signal ICTR, generates the output control signal, and adjusts the load loop of the high-voltage circuit. The power supply module provides stable power to the voltage isolation chip IC7, current isolation chip IC9, operational amplifier IC1, operational amplifier IC2, and control chip U14 through an isolated power supply, ensuring electrical isolation between the high-voltage and low-voltage circuits. The filtering circuit includes parallel capacitors C93, C94, C106, and C108, as well as series capacitors C95 and C96, which filter out signal noise, ensuring signal stability and thus improving the accuracy and reliability of the control system. The control circuit uses resistors R38 and R43 connected in series in the path of the control signal VCTRL to limit the signal amplitude, preventing it from being too large or too small. It then transmits the voltage sampling signal and the user-input strength signal, along with capacitor C95, to operational amplifier IC2 to generate the control signal VCTRL. Capacitor C95 is connected in parallel between the voltage divider point of resistors R38 and R43 and the ground terminal, and capacitor C96 is connected in parallel between the output terminal of operational amplifier IC2 and the ground terminal to further stabilize the output signal. The voltage sampling module is connected to a non-inverting adder IC8 via voltage isolation chip IC7. The non-inverting adder adds the low-voltage signal from the voltage sampling module to the control signal VCTRL to generate a control signal that adjusts the output voltage.

[0037] The voltage isolation chip IC7 is connected to the output of the high-voltage signal divider network via pin 1 (VINP), and pin 2 (VINN) is connected to the high-voltage ground terminal as a reference ground. Pin 3 (VDD1) is connected to the positive voltage of the high-voltage isolation power supply to provide the chip's operating voltage. Pin 4 (GND1) is connected to the high-voltage ground. Pin 5 (VOUT) outputs the isolated low-voltage signal and is connected to filter capacitors C93 and C94. Pins 6 (VDD2) and 7 (GND2) are connected to the positive terminal and ground of the low-voltage isolation power supply, respectively, for low-voltage power supply.

[0038] Pin 1 (VINP) and pin 2 (VINN) of the current isolation chip IC9 are connected to the two ends of the current sampling resistor R57 respectively to acquire the current signal; pin 3 (VDD1) is connected to the positive terminal of the high-voltage side isolation power supply to provide the chip's operating voltage; pin 4 (GND1) is connected to the high-voltage side ground; pin 5 (VOUTP) and pin 6 (VOUTN) output the positive and negative terminals of the isolated current signal respectively, and are connected to filter capacitors C106 and C108; pin 7 (VDD2) and pin 8 (GND2) are connected to the positive terminal and ground of the low-voltage side isolation power supply respectively.

[0039] In operational amplifier IC1 and operational amplifier IC2, pin 1 (OUT1) of operational amplifier IC1 outputs the current limiting control signal ICTR, and pin 7 (OUT2) of IC2 generates the control signal VCTRL; pin 2 (IN1-) of operational amplifier IC1 receives the filtered current signal, and pin 3 (IN1+) of operational amplifier IC1 is grounded or connected to a reference signal.

[0040] Pin 5 (IN2+) of operational amplifier IC2 receives the voltage sampling signal and the user strength signal; pin 6 (IN2-) of operational amplifier IC2 is connected to the control circuit (R38, R43) and the filter capacitor C95; pin 4 (VSS) and pin 8 (VDD) are connected to the low-voltage side ground and the low-voltage power supply positive terminal, respectively.

[0041] Pin 1 (VCC) and pin 2 (GND) of the control chip U14 are connected to the positive terminal of the low-voltage side isolation power supply and ground, respectively; pin 3 (ICTRL) receives the current limiting control signal ICTR, which is used to control the output current; pin 4 (VCTRL) receives the control signal VCTRL, which is used to regulate the output voltage; pins 5 and 6 (FB+ / FB-) ​​are connected to the feedback signal of the load circuit; pins 7 and 8 (OUT+ / OUT-) serve as output terminals and are connected to the load circuit to control the high-voltage output.

[0042] The in-phase adder IC8 is part of the operational amplifier. Its pin 1 (OUT1) outputs the signal after addition processing to adjust the output voltage; pin 3 (IN1+) receives the low voltage signal and control signal VCTRL from the voltage isolation chip IC7; the other pins are configured the same as those of operational amplifiers IC1 and IC2.

[0043] Working Principle: The voltage sampling module divides the high-voltage signal (400V-1200V) using a series resistor network, reducing it to a low voltage range suitable for subsequent processing. Simultaneously, the working status is indicated by the indicator LED1. The divided signal is then input to the voltage isolation chip IC7 (AMC1311DWVR). Its internal isolation structure electrically isolates the high-voltage signal and converts it into a low-voltage output signal. This design effectively protects the low-voltage circuit from high-voltage interference and improves circuit safety. The current sampling module detects the load current through sampling resistor R57 and inputs the current signal as a voltage to the current isolation chip IC9 (AMC1301DWVR). IC9 isolates the sampled signal and outputs the low-voltage signal to the filter circuit. The filter circuit removes high-frequency noise from the signal using capacitors C106 and C108, ensuring a stable and reliable current signal to the signal processing module. This module achieves real-time monitoring of the load current through precise sampling of the current signal. The signal processing module includes two operational amplifiers, IC1 and IC2 (LMV358IDR). IC2 receives the low-voltage signal and user intensity signal from the voltage sampling module, and generates a control signal VCTRL through the control circuit (including R38, R43, and C95) to regulate the output voltage. IC1 receives the filtered current signal, and generates a current-limiting control signal ICTR through further control and filtering to regulate the output current. By separating the control paths for voltage and current, this module achieves precise adjustment of the working state of the magnetic therapy device. The output control module, with the control chip U14 (EG4321) as its core, receives the control signal VCTRL and the current-limiting signal ICTR generated by the signal processing module, and adjusts the output voltage and current in real time through the feedback network. The output of U14 is connected to the load circuit to dynamically adjust the output of the high-voltage circuit, ensuring the stable operation of the magnetic therapy device under different working conditions. The feedback network further enhances the rapid response capability to output changes, and the filtering circuit, through the combination of components such as capacitors C93, C94, C95, and C96, suppresses noise in the voltage and current signals, removes high-frequency interference, and ensures signal purity. The filtering circuit is set at the voltage isolation chip, operational amplifier input, and output terminals to ensure high stability and anti-interference capability at every stage of signal acquisition, processing, and output. The control circuit consists of resistors R38 and R43 and capacitors C95 and C96, which limits the amplitude of the control signal VCTRL and the current limiting signal ICTR to prevent the signal from exceeding the safe range or causing overload due to abnormal interference. This design not only protects the components of subsequent circuits but also improves the accuracy of signal processing. The non-inverting adder IC8 (LMV358IDR) receives the low-voltage signal from the voltage isolation chip and the control signal VCTRL, and generates an output signal through superposition processing to further adjust the voltage level at the output terminal.The introduction of the adder enables the fusion processing of multiple signals, resulting in more precise control. The isolated power supply module supplies power to both the high-voltage and low-voltage circuits separately, while ensuring electrical isolation between the two sides. This power supply design effectively prevents high-voltage interference to the low-voltage circuits, ensuring the safety and reliability of the entire device.

[0044] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and all such equivalent transformations fall within the protection scope of the present invention.

Claims

1. A voltage and current control circuit for a magnetic therapy device, characterized in that: It includes a voltage sampling module, a current sampling module, a signal processing module, an output control module, and a power supply module; The voltage sampling module is connected to the operational amplifier 1C2 of the signal processing module after being isolated and filtered by the voltage isolation chip 107 through a voltage divider resistor network. The current sampling module is connected to operational amplifier IC1 via sampling resistor R57 and current isolation chip 109. The signal processing module is connected to the voltage sampling module, the current sampling module, the output control module, and the power supply module via the control chip U14.

2. The voltage and current control circuit of the magnetic therapy device according to claim 1, characterized in that: The voltage sampling module divides the high-voltage signal through a series of resistors R28, R29, R37, R78, R87, R95, R96, R44, and R47, and then inputs it to the input terminal of the voltage isolation chip IC7. The voltage isolation chip IC7 outputs the isolated low-voltage signal, which passes through capacitors C93 and C94 in the filter circuit and a series of resistors R39 and R36, and is then transmitted to the input terminal of the operational amplifier IC2 of the signal processing module. The current sampling module acquires the current signal on the high-voltage side through the sampling resistor R57. The voltage signals at both ends are input to the input terminal of the current isolation chip IC9. The current isolation chip IC9 outputs the isolated low-voltage signal, which is directly transmitted to the input terminal of the operational amplifier IC1 of the signal processing module after passing through capacitors C106 and C108 in the filter circuit.

3. The voltage and current control circuit of the magnetic therapy device according to claim 1, characterized in that: The signal processing module consists of operational amplifier IC2 and operational amplifier IC1. Operational amplifier IC2 receives voltage sampling signals and user intensity signals through the voltage sampling module, generates control signal VCTRL, and transmits it to the output control module. Operational amplifier IC1 receives current sampling signals and generates current limiting control signals ICTR. The output signal is further stabilized by filtering and control circuits. The output control module is based on control chip U14. The output terminal acts on the high-voltage circuit through the load loop and is connected to the feedback network. The power module is connected to the voltage isolation chip IC7 and current isolation chip IC9 on the high-voltage side and the operational amplifier IC1, operational amplifier IC2 and control chip U14 on the low-voltage side via isolated power supply.

4. The voltage and current control circuit of the magnetic therapy device according to claim 3, characterized in that: The filtering circuit includes capacitors C93 and C94 connected in parallel to the output of voltage isolation chip IC7; capacitors C106 and C108 connected in parallel to the output of current isolation chip IC9; capacitor C95 connected in series to the input of operational amplifier IC2 in the signal processing module; and capacitor C96 connected in parallel to the output of operational amplifier IC2.

5. The voltage and current control circuit of the magnetic therapy device according to claim 3, characterized in that: The control circuit includes resistors R38 and R43 connected in series in the path of the control signal VCTRL; one end of the control circuit is connected to the control signal VCTRL, and the other end is connected to capacitor C95 and the input terminal of operational amplifier IC2. Capacitor C95 is connected in parallel between the node of resistors R38 and R43 connected in series and the ground terminal, and capacitor C96 is connected in parallel between the output terminal of operational amplifier IC2 and the ground terminal.

6. The voltage and current control circuit of the magnetic therapy device according to claim 5, characterized in that: The voltage sampling module is connected to the non-inverting adder IC8 through the voltage isolation chip IC7. At the same time, the control signal VCTRL is transmitted to the filter capacitor C95 after being divided by the series resistors R38 and R43. The filter capacitor C95 is connected in parallel between the voltage division point of resistors R38 and R43 and the ground terminal, and is transmitted to the input terminal of the non-inverting adder IC8.

7. The voltage and current control circuit of the magnetic therapy device according to claim 6, characterized in that: The high-voltage signal input to the voltage sampling module is 400V-1200V. Resistors R28, R29, R37, R78, R87, R95, R96, R44, and R47 are connected in series between the high-voltage signal and the high-voltage ground terminal. A working indicator LED1 is provided between resistor R28 and the high-voltage signal. The resistance of resistors R28, R29, R37, and R78 is 1000KΩ, the resistance of resistors R87, R95, R96, and R44 is 200KΩ, and the resistance of resistor R47 is 10KΩ-20KΩ.

8. The voltage and current control circuit of the magnetic therapy device according to claim 4, characterized in that: The voltage isolation chip IC7 uses an AMC1311DWVR chip, the current isolation chip IC9 uses an AMC1301DWVR chip, the operational amplifier IC1 and the operational amplifier IC2 use an LMV358IDR chip, and the control chip U14 uses an EG4321 chip.

9. The voltage and current control circuit of the magnetic therapy device according to claim 6, characterized in that: The in-phase adder IC8 uses the LMV358IDR chip.

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