A gutta-percha cut-off control circuit, method and gutta-percha cut-off apparatus

Abstract

The present application relates to the technical field of gutta-percha cutters, and discloses a gutta-percha cutting control circuit, a method and a gutta-percha cutting device. In the control circuit, the working tip comprises a first conductor and a second conductor which are in contact with each other and form a thermocouple structure; a driving circuit is used to drive the working tip to heat based on a PWM driving signal; a main controller is used to acquire a current signal of the working tip and a thermoelectric electromotive force signal between the first conductor and the second conductor, to operate the current signal and the thermoelectric electromotive force signal, and to adjust and output the PWM driving signal to control the temperature of the working tip. The heat generating component is directly reused as a temperature sensing element by using the thermoelectric effect, without the need to additionally install a temperature control probe in the limited space of the working tip, and the temperature electrical signal is directly acquired from the heat source, thus fundamentally solving the problem of inaccurate temperature control caused by the fact that sensors cannot be installed at the front end of small medical devices due to insufficient space, and greatly improving the safety of clinical operations.

Description

Technical Field

[0001] This invention relates to the field of gutta-percha cutter technology, and more particularly to a gutta-percha cutting control circuit, method, and device. Background Technology

[0002] A gutta-percha cutter is a hot-melt gutta-percha filling system. It is used to quickly cut off excessively long gutta-percha points outside the root canal after lateral or vertical pressure filling, ensuring that the filling length matches the working length of the root canal and avoiding occlusal interference or insufficient filling. Heated cutters can soften the gutta-percha instantly before cutting, resulting in a clean cut without debris residue, reducing cleaning difficulty. Therefore, the speed of heating the working point and the ability to accurately control the heating temperature are the most important factors in the gutta-percha cutting process.

[0003] In current technology, commercially available electric gutta-percha cutters mainly consist of a working tip, a heating drive, and a lithium battery. The working tip contains a heating wire encased in a stainless steel shell. During operation, the drive circuit heats and cools the working tip by switching it on and off between the working tip and the battery. Because the heating end of the gutta-percha tip is at the front, it cannot be directly measured using common temperature sensors. Existing temperature control schemes for gutta-percha cutters primarily rely on preset fixed power or heating time. This approach is highly susceptible to environmental factors and working tip wear, leading to significant temperature control deviations, sometimes exceeding 50%, which can easily cause clinical burns or incomplete gutta-percha cutting.

[0004] Therefore, how to achieve high-precision, real-time temperature feedback and closed-loop control of the working tip of a gutta-percha cutter without adding additional sensors is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] This invention provides a gutta-percha cutting control circuit, method, and gutta-percha cutting device to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A gutta-percha cutting control circuit, comprising:

[0008] Working tip, main controller, and drive circuit;

[0009] The working tip includes a first conductor and a second conductor that are in contact with each other, and the first conductor and the second conductor form a thermocouple structure;

[0010] The drive circuit is electrically connected to the main controller and the working tip, and is used to drive the working tip to heat based on the PWM drive signal;

[0011] The main controller is used to output an initial PWM drive signal to the drive circuit, and to acquire the current signal of the working tip and the thermoelectric potential signal between the first conductor and the second conductor; the main controller is also used to perform calculations on the current signal and the thermoelectric potential signal, adjust the initial PWM drive signal and output the adjusted PWM drive signal to control the temperature of the working tip.

[0012] Optionally, the main controller is configured to acquire the thermoelectric potential signal during the low level of the PWM drive signal and acquire the current signal of the working tip during the high level of the PWM drive signal.

[0013] Optionally, the first conductor is a heating core inside the working tip, and the second conductor is a metal jacket covering the outside of the heating core.

[0014] Optionally, the gutta-percha cutting control circuit further includes a power supply for powering the temperature control circuit;

[0015] The driving circuit includes a fifth gate driver chip and an N-channel field-effect transistor; the input terminal of the fifth gate driver chip is connected to the main controller, and the output terminal is connected to the gate of the N-channel field-effect transistor; the N-channel field-effect transistor is connected in series between the power supply and the working tip.

[0016] Optionally, the gutta-percha cutting control circuit further includes a current and temperature acquisition circuit, which includes a seventh operational amplifier; the input terminal of the seventh operational amplifier is connected to the first conductor and the second conductor respectively, and the output terminal is connected to the main controller.

[0017] Optionally, it also includes a capacitive touch sensing circuit, which includes a touch chip and a sensing copper ring; the sensing copper ring is electrically connected to the sensing input terminal of the touch chip, and the signal output terminal of the touch chip is electrically connected to the main controller;

[0018] The touch chip is used to output a digital level transition signal as a trigger signal to the main controller through the signal output terminal when it senses a human body approaching or touching the sensing copper ring, so as to wake up the main controller.

[0019] Optionally, the gutta-percha cutting control circuit further includes a power management circuit, a buzzer, a display screen, buttons, and a Bluetooth communication module; the power management circuit outputs a drive voltage and a system voltage, which are respectively used to supply the drive circuit and the main controller; the buzzer, display screen, buttons, and Bluetooth communication module are all electrically connected to the main controller.

[0020] The present invention also provides a gutta-percha cutting control method, applied to the gutta-percha cutting control circuit as described in any of the preceding claims, comprising:

[0021] The initial PWM drive signal is output to the drive circuit to drive the working tip to heat up;

[0022] The current signal of the working tip and the thermoelectric potential signal between the first conductor and the second conductor are collected. The current signal and the thermoelectric potential signal are calculated, adjusted and output to control the temperature of the working tip.

[0023] A gutta-percha cutting device, comprising a gutta-percha cutting control circuit as described in any of the preceding claims.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] This invention provides a gutta-percha cutting control circuit, method, and gutta-percha cutting device. By forming a thermocouple structure between the first and second conductors of the working tip, the heating element is directly reused as a temperature sensing element using the thermoelectric effect. This eliminates the need for an additional temperature control probe in the limited space of the working tip and directly obtains the temperature signal from the heating source. This fundamentally solves the problem of inaccurate temperature control caused by insufficient space to install sensors at the front end of small medical devices, and significantly improves the safety of clinical surgery.

[0026] The present invention has other features and advantages, which will be apparent from or will be set forth in detail in the accompanying drawings and the following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a structural block diagram of a gutta-percha cutting control circuit provided in an embodiment of the present invention;

[0029] Figure 2 This is a partial structural schematic diagram of a gutta-percha cutting control circuit provided in an embodiment of the present invention;

[0030] Figure 3 This is another partial structural schematic diagram of a gutta-percha cutting control circuit provided in an embodiment of the present invention;

[0031] Figure 4 This is another partial structural schematic diagram of a gutta-percha cutting control circuit provided in an embodiment of the present invention.

[0032] Reference numerals: 10, working tip; 20, main controller; 30, drive circuit; 40, lithium battery; 50, current and temperature acquisition circuit; 60, power management circuit; 70, buzzer; 80, display screen; 90, button; 100, Bluetooth communication module; 110, capacitive touch sensing circuit. Detailed Implementation

[0033] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0034] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0035] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0036] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0037] In this application, 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 actual quantity, hierarchy or order relationship between these entities or operations.

[0038] Unless otherwise specified, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0039] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0040] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0041] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. For those skilled in the art to which this application pertains, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0042] The present invention aims to provide a temperature control circuit for a gutta-percha cutter, which utilizes the physical structure of the working tip itself to achieve a self-sensing temperature function, thereby eliminating the need for a traditional temperature sensor and achieving precise temperature control.

[0043] The present invention will now be described in detail with reference to the accompanying drawings.

[0044] Please refer to Figures 1 to 3 This embodiment discloses a gutta-percha cutting control circuit, including a working tip 10, a main controller 20, a drive circuit 30, a power supply, a current and temperature acquisition circuit 50, a power management circuit 60, a buzzer 70, a display screen 80, buttons 90, a Bluetooth communication module 100, and a capacitive touch sensing circuit 110.

[0045] The working tip 10 serves as the execution end and includes a first conductor and a second conductor that are in contact with each other, forming a thermocouple structure.

[0046] Generally, the heating end of the working tip 10 of a gutta-percha cutter is located at the front end, where the space is too small to install a conventional temperature sensor. Most products lack precise temperature control, resulting in large temperature errors and problems such as poor cutting effect or burns to patients.

[0047] In this embodiment, the working tip 10 is configured to include a first conductor and a second conductor in contact with each other, both made of different metallic materials, thereby forming a thermocouple structure. Based on the Seebeck effect, when the working tip 10 is heated, a thermoelectric electromotive force signal proportional to the temperature is generated between the first conductor and the second conductor, enabling temperature detection without the need for an additional temperature sensor.

[0048] In some alternative implementations, the first conductor is the heating core inside the working tip 10, and the second conductor is a metal jacket covering the outside of the heating core. This composite structure integrates heating and temperature measurement functions.

[0049] Understandably, since the working tip contains a heating wire inside and stainless steel on the outside, according to the thermoelectric effect (Seebeck effect): when two different conductors (or semiconductors) A and B form a closed circuit, and the two contact ends (junctions) are at different temperatures (T measuring end / hot end, T0 reference end / cold end), a thermoelectric potential (thermoelectric electromotive force) related to the temperature difference will be generated in the circuit, thus forming a weak current. Therefore, the working tip is equivalent to a thermocouple. When it heats up, there will be a potential difference between its external cold end and internal cold end. By detecting this potential difference and comparing it with the potential difference measured during calibration testing, and then linearly interpolating, the temperature of the hot end of the working tip can be measured.

[0050] In this embodiment, the driving circuit 30 is electrically connected to the main controller 20 and the working tip 10, and is used to drive the working tip 10 to heat based on the PWM driving signal.

[0051] Specifically, the driving circuit 30 includes a fifth gate driver chip U5 and an N-channel MOSFET Q7. The input terminal of the fifth gate driver chip U5 is connected to the main controller 20, and the output terminal is connected to the gate of the N-channel MOSFET Q7. The N-channel MOSFET Q7 is connected in series between the power supply and the working tip 10, and is used to drive the working tip 10 to heat based on the PWM drive signal.

[0052] When heating the working tip by switching it on and off, the commonly used P-channel MOSFET is replaced by a gate driver chip combined with an N-channel MOSFET. The low on-resistance of the N-channel MOSFET and the stable drive of the gate driver chip effectively improve the heating efficiency of the working tip.

[0053] In addition, a seventeenth resistor is connected between the fifth pin of the fifth gate driver chip U5 and the gate of the N-channel MOSFET Q7. The second and fourth pins of the fifth gate driver chip U5 are grounded, the first pin is connected to the drive voltage output by the power management circuit 60, and the third pin is connected to the main controller 20. A sixteenth resistor R16 is connected between the gate of the N-channel MOSFET Q7 and ground. The source of the N-channel MOSFET Q7 is connected to the heating element of the working tip 10, and the drain is connected to the power supply. The power supply is a lithium battery 40.

[0054] Based on this, the driving circuit 30 adopts a driving method that combines a gate driving chip with an N-channel field-effect transistor. By utilizing the low on-resistance characteristic of the N-channel field-effect transistor and the stable driving capability of the gate driving chip, the heat dissipation efficiency of the working tip 10 can be improved, and the circuit's own losses and heat generation can be reduced.

[0055] It is understood that the main controller 20 is the control core of the circuit, and in this embodiment, the main controller 20 outputs the initial PWM drive signal to the drive circuit 30. Simultaneously, the main controller 20 is connected to the current and temperature acquisition circuit 50 to acquire the current signal of the working tip 10 and the thermoelectric potential signal between the first and second conductors. The main controller 20 is also used to perform calculations on the current and thermoelectric potential signals, adjust the initial PWM drive signal, and output the adjusted PWM drive signal to control the temperature of the working tip 10.

[0056] In some optional implementations, to avoid interference from the heating current on the weak thermoelectric potential signal, this embodiment employs time-division sampling. Specifically, the main controller 20 acquires the thermoelectric potential signal during the low level of the PWM drive signal and acquires the current signal of the working tip 10 during the high level of the PWM drive signal. When the PWM drive signal is high, the working tip 10 is energized for heating, and the large current will interfere with the weak thermoelectric potential signal. Acquiring the current signal of the working tip 10 at this time can monitor abnormal operating states such as short circuits and open circuits of the working tip 10. When the PWM drive signal is low, the working tip 10 stops heating, and there is no heating current interference. The thermoelectric potential signal acquired at this time is pure and can accurately reflect the temperature of the working tip 10.

[0057] In some optional embodiments, the current and temperature acquisition circuit 50 includes a seventh operational amplifier U7. The input terminals of the seventh operational amplifier U7 are connected to the first and second conductors respectively, and the output terminal is connected to the main controller 20, used to amplify the thermoelectric potential signal and output it to the main controller 20. The third pin of the seventh operational amplifier U7 is connected to the system voltage output by the power management circuit 60, the first, second, and fifth pins are grounded, the fourth pin is connected to the system voltage through the twenty-second resistor R22, the sixth pin is connected to the main controller 20 through the twenty-second resistor R23, and the metal jacket of the working tip 10 is connected to the fourth pin of the seventh operational amplifier U7.

[0058] Specifically, the third pin of the seventh operational amplifier U7 is connected to the 3.3V output of the power management circuit, the first, second, and fifth pins are grounded, and the fourth pin is connected to the 3.3V output of the power management circuit through the twenty-second resistor R22. In this embodiment, the thermoelectric electromotive force generated by the thermocouple is a weak signal in the millivolt range. After being amplified by the seventh operational amplifier U7, it can be accurately identified and acquired by the main controller 20.

[0059] Furthermore, in this embodiment, in order to achieve high-precision temperature control, the main controller 20 adopts a position-based PID control algorithm to calculate the real-time temperature based on the thermoelectric potential signal, and adjusts the duty cycle of the PWM drive signal according to the deviation between the real-time temperature and the preset temperature.

[0060] Specifically, the main controller 20 outputs an initial PWM drive signal to the drive circuit 30 according to the user setting to drive the working tip 10 to heat up. Then, the main controller 20 samples the current during the high level time of the PWM signal and samples the potential difference during the low level time. After amplifying the two sets of signals through an operational amplifier, they are sent to the main controller for position-based PID algorithm calculation. Based on the result, the working tip heating drive signal is automatically adjusted so that the working tip is quickly heated to the set temperature and kept stable.

[0061] In this embodiment, the power supply is provided by the power management circuit 60. The power management circuit 60 is used to manage the charging and discharging of the lithium battery, and outputs a drive voltage and a system voltage. The drive voltage supplies the drive circuit 30, and the system voltage supplies the main controller 20 and other control modules.

[0062] Please refer to Figure 4 In this embodiment, the capacitive touch sensing circuit 110 is electrically connected to the main controller 20, and includes a touch chip U4 and a sensing copper ring; the sensing copper ring is electrically connected to the sensing input terminal of the touch chip U4, specifically the fifth pin; the signal output terminal of the touch chip U4 is electrically connected to the main controller 20; the touch chip U4 is used to output a digital level transition signal to the main controller 20 as a trigger signal through its signal output terminal when it senses a human body approaching or touching the sensing copper ring, so as to wake up the main controller 20 or start other functions.

[0063] Specifically, the touch chip U4 can be a BS812A-1. Its pin connections are as follows: pin KEY2 is electrically connected to the sensing copper ring, and a ground filter capacitor C10 is installed on the line; pin KOUT2 serves as the signal output terminal and is connected to the interrupt input port of the main controller 20. The power supply pin VDD is connected to 3.3V and supplemented with a filter capacitor C9.

[0064] Based on this, when a conductor such as a finger approaches or touches the sensing copper ring, the capacitance of the sensing circuit changes. After the touch chip U4 detects the change, its fourth pin outputs a digital level transition signal as a trigger signal, which is sent to the main controller 20. The main controller 20 then executes an interrupt program to wake up or start other specified functions, achieving contactless triggering. This ring-shaped sensing structure enables 360-degree operation response and improves the overall sealing and service life of the device.

[0065] In addition, the buzzer 70, display screen 80, button 90 and Bluetooth communication module 100 are all electrically connected to the main controller 20. The buzzer 70 is used to emit prompt sounds and alarm signals, the display screen 80 is used to display parameters such as temperature and working status, the button 90 is used for manual operation control by the user, and the Bluetooth communication module 100 is used to send the system operation information of the gutta-percha cutter to an external Bluetooth terminal to realize data synchronization and remote viewing.

[0066] Based on the above embodiments, this embodiment discloses a gutta-percha cutting control method, applied to the gutta-percha cutting control circuit in Embodiment 1. The method includes the following steps:

[0067] S1. Output the initial PWM drive signal to the drive circuit 30 to drive the working tip 10 to heat up;

[0068] S2. Acquire the current signal of the working tip 10 and the thermoelectric potential signal between the first conductor and the second conductor, perform calculations on the current signal and the thermoelectric potential signal, adjust and output the adjusted PWM drive signal to control the temperature of the working tip 10.

[0069] Specifically, in this embodiment, the main controller 20 controls the acquisition logic. During the high level of the PWM drive signal, the current signal of the working tip 10 is acquired through the current and temperature acquisition circuit 50; during the low level of the PWM drive signal, the thermoelectric potential signal generated between the first conductor and the second conductor is acquired; the thermoelectric potential signal is amplified by the seventh operational amplifier U7 of the current and temperature acquisition circuit 50 and then transmitted to the main controller 20; the main controller 20 performs calculations on the current signal and the thermoelectric potential signal, and uses a positional PID control algorithm to adjust the duty cycle of the PWM drive signal according to the deviation between the real-time temperature and the preset temperature, and outputs the adjusted PWM drive signal. The above steps are executed cyclically to achieve closed-loop control of the temperature of the working tip 10.

[0070] In this method, a drive circuit is formed by combining a gate driver chip with an N-channel MOSFET. The circuit receives the PWM drive signal output by the main controller to control the heating operation of the working tip. Compared with the conventional P-channel MOSFET drive method, the low on-resistance characteristic of the N-channel MOSFET and the stable drive capability of the gate driver chip effectively improve the heating response speed and heating efficiency, and reduce circuit losses in the control process.

[0071] Furthermore, in this embodiment, a time-division alternating sampling acquisition control logic is adopted. During the high-level heating period of the PWM drive signal, the working current of the working tip is synchronously acquired to monitor abnormal operating conditions such as short circuit and open circuit of the working tip in real time.

[0072] Specifically, during the heating pause period when the PWM drive signal is low, the thermoelectric potential signal generated by the working tip is collected to avoid interference from the large heating current on the weak temperature measurement signal, ensuring the purity and accuracy of the temperature sampling data. The main control unit calculates the real-time temperature of the working tip based on the collected thermoelectric potential signal, and combines it with the difference from the preset target temperature. The position-based PID control algorithm dynamically corrects and adjusts the duty cycle of the PWM drive signal to form a continuous closed-loop temperature regulation, achieving precise constant temperature control of the working tip.

[0073] In addition, the method provided in this embodiment also includes capacitive touch sensing control logic. By detecting the capacitance change of the sensing copper ring in real time, when a human body is detected to be close or a touch is triggered, the touch sensing module sends a level transition trigger signal to the main controller. The interrupt command is responded to complete the corresponding operations such as device wake-up and function start / stop. The ring sensing trigger method is adopted to realize all-round contactless sensing control, which simplifies the operation process, reduces the wear and tear of mechanical button structure, and improves the overall sealing protection performance and durability of the device.

[0074] Based on the above embodiments, this embodiment discloses a gutta-percha cutting device, including the gutta-percha cutting control circuit in the aforementioned embodiments. This device achieves sensorless self-temperature measurement through the thermocouple structure of the working tip 10 itself. Combined with time-division sampling and position-based PID closed-loop temperature control, it achieves precise temperature control of the working tip 10 within a confined space. It also features efficient drive, stable power supply, convenient human-machine interaction, and remote data transmission capabilities, making it suitable for rapid and safe gutta-percha cutting operations in dental root canal treatment.

[0075] Finally, it should be noted that although the above embodiments have been described in the text and drawings of this application, this should not be construed as limiting the scope of protection of this application. Any technical solutions resulting from equivalent structural or procedural substitutions or modifications made based on the essential concept of this application and utilizing the content described in the text and drawings of this application, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of protection of this application.

Claims

1. A gutta-percha cutting control circuit, characterized in that, include: Working tip, main controller, and drive circuit; The working tip includes a first conductor and a second conductor that are in contact with each other, and the first conductor and the second conductor form a thermocouple structure; The drive circuit is electrically connected to the main controller and the working tip, and is used to drive the working tip to heat based on the PWM drive signal; The main controller is used to output an initial PWM drive signal to the drive circuit, and to acquire the current signal of the working tip and the thermoelectric potential signal between the first conductor and the second conductor; the main controller is also used to perform calculations on the current signal and the thermoelectric potential signal, adjust the initial PWM drive signal and output the adjusted PWM drive signal to control the temperature of the working tip.

2. The gutta-percha cutting control circuit according to claim 1, characterized in that, The main controller is used to acquire the thermoelectric potential signal during the low level of the PWM drive signal and to acquire the current signal of the working tip during the high level of the PWM drive signal.

3. The gutta-percha cutting control circuit according to claim 1, characterized in that, The first conductor is the heating core inside the working tip, and the second conductor is a metal jacket covering the outside of the heating core.

4. The gutta-percha cutting control circuit according to claim 1, characterized in that, It also includes a power supply for powering the temperature control circuit; The driving circuit includes a fifth gate driver chip and an N-channel field-effect transistor; the input terminal of the fifth gate driver chip is connected to the main controller, and the output terminal is connected to the gate of the N-channel field-effect transistor; the N-channel field-effect transistor is connected in series between the power supply and the working tip.

5. The gutta-percha cutting control circuit according to claim 1, characterized in that, It also includes a current and temperature acquisition circuit, which includes a seventh operational amplifier; the input terminal of the seventh operational amplifier is connected to the first conductor and the second conductor respectively, and the output terminal is connected to the main controller.

6. The gutta-percha cutting control circuit according to claim 1, characterized in that, It also includes a capacitive touch sensing circuit, which includes a touch chip and a sensing copper ring; the sensing copper ring is electrically connected to the sensing input terminal of the touch chip, and the signal output terminal of the touch chip is electrically connected to the main controller; The touch chip is used to output a digital level transition signal as a trigger signal to the main controller through the signal output terminal when it senses a human body approaching or touching the sensing copper ring, so as to wake up the main controller.

7. The gutta-percha cutting control circuit according to claim 1, characterized in that, It also includes a power management circuit, which outputs a drive voltage and a system voltage, which are used to supply power to the drive circuit and the main controller, respectively.

8. The gutta-percha cutting control circuit according to claim 1, characterized in that, It also includes a buzzer, a display screen, buttons, and a Bluetooth communication module, all of which are electrically connected to the main controller.

9. A method for controlling gutta-percha cutting, applied to the gutta-percha cutting control circuit according to any one of claims 1-8, characterized in that, include: The initial PWM drive signal is output to the drive circuit to drive the working tip to heat up; The current signal of the working tip and the thermoelectric potential signal between the first conductor and the second conductor are collected. The current signal and the thermoelectric potential signal are calculated, adjusted and output to control the temperature of the working tip.

10. A gutta-percha cutting device, characterized in that, Includes the gutta-percha cutting control circuit as described in any one of claims 1-8.

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