Series high-frequency current sampling circuit
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NANJING ECO MICROWAVE SYST
- Filing Date
- 2025-06-23
- Publication Date
- 2026-06-23
AI Technical Summary
Existing current sampling methods are easily affected by temperature and voltage, resulting in low accuracy and affecting the normal operation of high-frequency surgical equipment.
A series high-frequency current sampling circuit is adopted, including a Hall current sensor, a Hall current detection component, a voltage follower component, an amplification component, and a filtering component. The current is detected by utilizing the Hall effect principle and the signal is protected from interference by the voltage follower component. Accurate measurement is achieved by combining the circuit with an RC filter circuit.
It enables accurate current measurement unaffected by external interference, reduces power loss, improves measurement accuracy, and ensures the smooth progress of the surgical procedure.
Smart Images
Figure CN224399487U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of medical device technology, specifically relating to a series high-frequency current sampling circuit. Background Technology
[0002] Compared to the complexity of traditional surgical instruments and the degree of trauma associated with surgical procedures, high-frequency surgical systems have made significant progress and development in the clinical medical field. They have greatly reduced the difficulty of surgery for clinicians and effectively minimized damage to patient tissues and wounds caused by surgical instruments. Behind the widespread use of high-frequency surgical systems in clinical medicine lies the continuous development and innovation of key technologies in power electronics and energy management. Current sampling, as a crucial technology, faces the challenge of providing more accurate and effective support for energy management and circuit condition monitoring, a topic that requires ongoing research and development.
[0003] Currently, the two commonly used current sampling methods are resistance sampling and mutual inductance sampling. Resistance sampling typically uses a manganin strip or a high-precision resistor with a very low temperature coefficient of resistance to measure the voltage drop across the resistor and directly sample the current according to Ohm's law. This method is easily affected by temperature and voltage, leading to inaccurate sampling and affecting the normal operation of high-frequency surgical equipment. Mutual inductance sampling, on the other hand, uses a current transformer to proportionally transform a large current into a smaller current for subsequent signal measurement. This sampling method has poor linearity and accuracy, and the transformer itself can also introduce significant errors due to the magnetizing inductance. Summary of the Invention
[0004] The technical problem to be solved by this utility model is to overcome the shortcomings of the above-mentioned technologies and propose a sampling circuit that can accurately measure the value of the real-time sampling current while ensuring that it is not affected by external circuit interference, thereby accurately controlling the output of the device and ensuring a smoother surgical process.
[0005] To solve the above-mentioned technical problems, the present invention proposes the following technical solution: a series high-frequency current sampling circuit, comprising: a Hall current sensor, a Hall current detection component, a voltage follower component, an amplification component, and a filtering component; the Hall current sensor is arranged on the current line to be measured, and the output of the Hall current sensor is connected to the input of the Hall current detection component; the output of the Hall current detection component is connected to the input of the voltage follower component, and the output of the voltage follower component is connected to the processor after passing through the amplification component and the filtering component in sequence.
[0006] A further improvement to the above scheme is that: the Hall current detection component includes a V / F conversion chip; the input of the V / F conversion chip is connected to the Hall current sensor; the output of the V / F conversion chip is first connected in series with a seventh capacitor, and then connected to the voltage follower component after passing through a resistor voltage divider structure; the V / F conversion chip can generate sine wave signals of different amplitudes according to the output voltage of the Hall current sensor.
[0007] A further improvement to the above scheme is that the voltage follower component is a voltage follower circuit composed of a first operational amplifier.
[0008] A further improvement to the above scheme is that the amplification component is an amplification circuit composed of a second operational amplifier.
[0009] A further improvement to the above scheme is that the filtering component is an RC filter circuit composed of a fourth resistor and an eleventh capacitor.
[0010] This invention provides a series high-frequency current sampling circuit that detects and obtains the Hall-induced electromotive force based on the Hall effect principle. A voltage follower component protects the signal from interference and filters out bias voltage, thus achieving accurate current measurement. Compared to the resistance sampling method, which directly calculates the current by amplifying the voltage signal across the sampling resistor using an operational amplifier circuit, this method requires consideration of the power loss inherent in resistance sampling and the error caused by temperature drift in high-precision resistors. The Hall sensor does not require an external detection resistor, resulting in minimal power loss. Compared to a current transformer, the Hall sensor outputs a signal by measuring the Hall-induced electromotive force rather than the induced current. When the measured current is distorted, has multiple harmonics, or is not sinusoidal, the accuracy of the current transformer sampling is significantly affected, making it less accurate than the Hall current sensor. The Hall current sensor detection circuit is relatively simple, using integrated components directly connected in series in the circuit to detect the current flowing through nearby lines. Attached Figure Description
[0011] The present invention will be further described below with reference to the accompanying drawings.
[0012] Figure 1 This is a schematic diagram of a preferred embodiment of the present invention.
[0013] Figure 2 This is a circuit diagram of a preferred embodiment of the present invention. Detailed Implementation
[0014] The series high-frequency current sampling circuit in this embodiment, such as Figure 1As shown, it includes: a Hall current sensor, a Hall current detection component, a voltage follower component, an amplification component, and a filtering component; the Hall current sensor is arranged on the current line to be measured, and the output of the Hall current sensor is connected to the input of the Hall current detection component; the output of the Hall current detection component is connected to the input of the voltage follower component, and the output of the voltage follower component is connected to the processor after passing through the amplification component and the filtering component in sequence.
[0015] like Figure 2 As shown, the Hall current detection component includes a V / F conversion chip U3. The V / F conversion chip U3 integrates a Hall sensor; therefore, in this embodiment, a separate Hall sensor is not required. The V / F conversion chip U3 is positioned next to the current line to be measured to detect the current on it. Interfaces J2 and J3 are provided to facilitate the introduction of the current to be measured into the circuit board. The output of the V / F conversion chip U3 is first connected in series with the seventh capacitor C7, then through a resistor divider structure and connected to the voltage follower component. The V / F conversion chip U3 is also connected to necessary power and ground. Capacitors C9 and C12 are decoupling capacitors for the power supply pins of the V / F conversion chip U3, and C8 is the filter capacitor for pin 6 of the V / F conversion chip U3. After receiving the voltage signal from the Hall current sensor, the V / F conversion chip U3 outputs a sine wave with a frequency Fs and an amplitude corresponding to the voltage signal of the Hall current sensor, based on the magnitude of the Hall current sensor's voltage signal. The Hall current detection component, through the seventh capacitor C7, provides DC isolation, isolating the Hall current sensor from subsequent processing circuits, thereby avoiding mutual interference. The voltage divider structure consists of resistors R5 and R6.
[0016] The voltage follower component is a voltage follower circuit composed of the first operational amplifier U5A. The voltage follower circuit can enhance the load-driving capability and improve signal stability.
[0017] The amplification component is an amplifier circuit composed of the second operational amplifier U2A. The resistors R1, R2, and R3 can be adjusted according to specific requirements to change the amplification factor. The amplifier circuit appropriately amplifies the waveform for easier subsequent identification.
[0018] Finally, the signal is transmitted to the microcontroller via a filter circuit consisting of resistor R4 and capacitor C11. The RC filter circuit formed by resistor R4 and capacitor C11 filters out noise from the sine wave output from the second operational amplifier U2A before inputting it to the microcontroller, ensuring that the values acquired by the microcontroller are accurate and stable.
[0019] This utility model is not limited to the above embodiments. All technical solutions formed by equivalent substitutions fall within the protection scope claimed by this utility model.
Claims
1. A series high-frequency current sampling circuit, characterized in that, include: Hall current sensor, Hall current detection component, voltage follower component, amplification component and filtering component; The Hall current sensor is arranged on the current line to be measured, and the output of the Hall current sensor is connected to the input of the Hall current detection component; the output of the Hall current detection component is connected to the input of the voltage follower component, and the output of the voltage follower component is connected to the processor after passing through the amplification component and the filtering component in sequence.
2. The series high-frequency current sampling circuit according to claim 1, characterized in that: The Hall current detection component includes a V / F conversion chip; the input of the V / F conversion chip is connected to the Hall current sensor; the output of the V / F conversion chip is first connected in series with a seventh capacitor, and then connected to the voltage follower component after passing through a resistor voltage divider structure; the V / F conversion chip can generate sine wave signals of different amplitudes according to the output voltage of the Hall current sensor.
3. The series high-frequency current sampling circuit according to claim 2, characterized in that: The voltage follower component is a voltage follower circuit composed of a first operational amplifier.
4. The series high-frequency current sampling circuit according to claim 3, characterized in that: The amplification component is an amplification circuit composed of a second operational amplifier.
5. The series high-frequency current sampling circuit according to claim 4, characterized in that: The filtering component is an RC filter circuit consisting of a fourth resistor and an eleventh capacitor.