High-frequency induction heating system

Abstract

The invention discloses a high-frequency induction heating system which comprises a driving control circuit, a power supply circuit and a high-frequency induction unit, the driving control circuit comprises a signal input unit, a driving control unit and a power switch unit, and the high-frequency induction unit comprises a voltage transformation unit and an induction coil. The PWM signal is sent to the power switch unit through the driving control circuit to enable the induction coil to be powered on, the circuit structure is simpler, and the response speed is higher.

Description

Technical Field

[0001] This invention relates to the field of induction heating technology, and more specifically to a high-frequency induction heating system. Background Technology

[0002] In the fields of mechanical maintenance, equipment disassembly and assembly, and construction engineering, metal fasteners (such as bolts, nuts, and screws) are prone to corrosion at their threaded joints due to long-term exposure to humid and corrosive environments or high-temperature oxidation, making it difficult to disassemble nuts and bolts due to corrosion.

[0003] Traditional methods for removing rusty screws mainly include the following: 1. Using a hammer to strike or an impact wrench to separate the rust products between the nut and the bolt through vibration or damage is a laborious and unsuccessful method with certain safety risks.

[0004] 2. Rust remover is used to penetrate and lubricate nuts and bolts. However, for severely rusted screws, the rust remover cannot penetrate effectively, which means that it takes a long time to disassemble them and may have adverse effects on the metal or plastic parts near the bolts.

[0005] 3. Using gas cutting equipment to heat corroded screws can damage metal or plastic parts near the bolts and pose a fire hazard.

[0006] Induction heating technology utilizes the principle of electromagnetic induction. The metal to be heated is placed inside an induction coil, and a changing electromagnetic field is generated within the coil by a high-frequency alternating current. This induces eddy currents within the metal, which generate Joule heating due to resistance, achieving rapid heating of the metal. This heating method has advantages such as high efficiency, fast heating speed, uniform heating, energy saving, and environmental friendliness, and it does not damage metal or plastic parts outside the induction coil. However, existing high-frequency induction heating systems suffer from high production costs and slow response speeds due to complex circuit designs.

[0007] The purpose of this application is to provide a high-frequency induction heating system that can solve at least one of the above-mentioned technical problems. Summary of the Invention

[0008] The purpose of this invention is to at least partially solve one of the technical problems in the related art. In view of this, a high-frequency induction heating system is provided, comprising: a drive control circuit, a power supply circuit, and a high-frequency induction unit, wherein the high-frequency induction unit is electrically connected to the drive control circuit and the power supply circuit respectively; the drive control circuit includes a signal input unit, a drive control unit, and a power switch unit; the high-frequency induction unit includes a transformer unit and an induction coil; and the power supply circuit has a first voltage terminal and a second voltage terminal. The drive control unit has a first input terminal, a second input terminal, a first output terminal, and a second output terminal. The first and second input terminals of the drive control unit are respectively connected to the first terminals of the corresponding signal input units. The first and second output terminals of the drive control unit are respectively connected to the control terminals of the corresponding power switch units. The center tap on the primary side of the transformer unit is electrically connected to the first voltage terminal of the power supply circuit. The two ends on the primary side of the transformer unit are respectively electrically connected to the first connection terminal of the corresponding power switch unit and the second terminal of the corresponding signal input unit. The secondary side of the transformer unit is electrically connected to the induction coil. The third terminal of the signal input unit and the drive control unit are respectively electrically connected to the second voltage terminal of the power supply circuit. The second connection terminal of the power switch unit is grounded. The drive control unit sends a PWM signal to the power switch unit to make it work alternately. The transformer unit inverts DC power into high-frequency AC power, which generates a magnetic field in the induction coil, causing the induction coil to induction heat the conductor workpiece located therein.

[0009] Compared with the prior art, the technical solution of the present invention has the following advantages: the PWM signal is sent to the power switching unit through the drive control circuit to energize the induction coil. The drive signal is sent directly through the drive control unit without passing through the microcontroller. The structure is simple, the cost is low, and the response speed is fast.

[0010] According to one embodiment of the present invention, a main control circuit is further included. The drive control circuit is electrically connected to the power supply circuit through the main control circuit. The main control circuit includes a main control unit and an electronic switch unit. The power supply circuit also has a third voltage terminal. The second voltage terminal of the power supply circuit is electrically connected to the third terminals of the drive control unit and the signal input unit through the electronic switch unit. The main control unit is electrically connected to the electronic switch unit and the third voltage terminal of the power supply circuit.

[0011] According to one embodiment of the present invention, a detection circuit is further included, the detection circuit including a first voltage acquisition unit, the input terminal of the first voltage acquisition unit being electrically connected to both ends of the primary side of the transformer unit and the center tap of the primary side of the transformer unit, respectively, and the first voltage acquisition unit being electrically connected to the second voltage terminal of the power supply circuit and the main control unit, respectively.

[0012] According to one embodiment of the present invention, the detection circuit further includes a second voltage acquisition unit, which is electrically connected to the first voltage terminal of the power supply circuit and the main control unit, respectively.

[0013] According to an example of the present invention, the power supply circuit includes a switching power supply unit, an AC-DC conversion unit, and a DC-DC conversion unit. The input terminal of the AC-DC conversion unit is electrically connected to an AC power source, and the output terminal of the DC-DC conversion unit forms the second voltage terminal and the third voltage terminal of the power supply circuit. The switching power supply unit is electrically connected to the output terminal of the AC-DC conversion unit and the DC-DC conversion unit, respectively. The switching power supply unit includes a zero-crossing detection unit, a first rectifier bridge unit, and a second rectifier bridge unit. One end of the second rectifier bridge unit is electrically connected to the main control unit through a zero-crossing detection unit, and the other end of the second rectifier bridge unit is electrically connected to the first rectifier bridge unit and the DC-DC conversion unit respectively. One end of the first rectifier bridge unit is electrically connected to the AC-DC conversion unit, and the other end of the first rectifier bridge unit forms the first voltage terminal of the power supply circuit. The DC-DC conversion unit is electrically connected to the main control unit and the electronic switch unit respectively.

[0014] According to one example of the present invention, the signal input unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first transistor, a second transistor, a first capacitor, a first diode, and a second diode; After the first, second, third, and fourth resistors are connected in series, one end of the first resistor is electrically connected to the primary side of the transformer unit, and the other end of the fourth resistor is electrically connected to the electronic switch unit. After the first and second diodes are connected in series, the cathode of the first diode is electrically connected to the primary side of the transformer unit, the anode of the second diode is electrically connected to the connection point between the second and third resistors, the connection point between the third and fourth resistors is electrically connected to the base of the first transistor, the emitter of the first transistor is electrically connected to the electronic switch unit, the collector of the first transistor is connected in series with the ground terminal with a fifth resistor, the collector of the first transistor is connected in series with the base of the second transistor with a first capacitor, the base of the second transistor is connected in series with the ground terminal with a sixth resistor, the emitter of the second transistor is grounded, and the first and second input terminals of the drive control unit are respectively electrically connected to the collectors of the corresponding second transistors.

[0015] According to one example of the present invention, the drive control unit includes a drive chip, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a second capacitor, a third diode, and a fourth diode; The first and second input terminals of the driver chip are electrically connected to the collectors of the corresponding second transistors. A seventh resistor is connected in series between the first input terminal and its first output terminal, and between the second input terminal and its second output terminal. The driver chip is electrically connected to the electronic switch unit. An eighth resistor and a second capacitor are connected in series between the first input terminal and its second output terminal, and between the second input terminal and its first output terminal. A ninth resistor is connected in series between the first and second output terminals of the driver chip and the control terminal of the corresponding power switch unit. A third diode is connected in parallel across the two ends of the ninth resistor. A tenth resistor and a fourth diode are connected in parallel between the control terminal and the ground terminal of the power switch unit.

[0016] According to one example of the present invention, the zero-crossing detection unit includes a first optocoupler, a first switching transistor, an eleventh resistor, a twelfth resistor, a third capacitor, a fifth diode, and a sixth diode; The receiving end of the first optocoupler is electrically connected to the main control unit. An eleventh resistor is connected in series between one end of the transmitting end of the first optocoupler and the first connection end of the first switching transistor. A twelfth resistor is connected in series between the other end of the transmitting end of the first optocoupler and the control end of the first switching transistor. A fifth diode is connected in series between the other end of the transmitting end of the first optocoupler and the second connection end of the first switching transistor. A sixth diode is connected in series between the second connection end of the first switching transistor and its control end. A third capacitor is connected in parallel across the two ends of the fifth diode. The two ends of the twelfth resistor are electrically connected to one end of the second rectifier bridge.

[0017] According to one example of the present invention, the first voltage acquisition unit includes a first comparator module, a second comparator module, and a third transistor; The first input terminal of the first comparator module is electrically connected to the first voltage terminal of the power supply circuit. The second input terminals of the first comparator module and the second input terminal of the second comparator module are electrically connected to the second voltage terminal of the power supply circuit. The first input terminal of the second comparator module is electrically connected to the two ends of the primary side of the transformer unit. The output terminals of the first comparator module and the second comparator module are electrically connected to the second voltage terminal of the power supply circuit. The output terminal of the first comparator module is electrically connected to the control terminal of the third transistor. The first connection terminal of the third transistor is grounded. The second connection terminal of the third transistor is electrically connected to the main control unit.

[0018] According to one example of the present invention, the electronic switching unit includes a fourth transistor, a fifth transistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, a seventh diode, a fourth capacitor, and a fifth capacitor; The first terminal of the fourth transistor is electrically connected to the second voltage terminal of the power supply circuit. The second terminal of the fourth transistor is electrically connected to the third terminals of the drive control unit and the signal input unit, respectively. A seventh diode is connected in series between the first terminal and the second terminal of the fourth transistor. A thirteenth resistor is connected in series between the control terminal and the first terminal of the fourth transistor. A fourteenth resistor, a fourth capacitor, and a fifth capacitor are connected in parallel in series between the second terminal of the fourth transistor and the ground terminal. A fifteenth resistor is connected in series between the control terminal of the fourth transistor and the first terminal of the fifth transistor. The second terminal of the fifth transistor is grounded. A sixteenth resistor is connected in series between the control terminal of the fifth transistor and the main control unit. A seventeenth resistor is connected in series between the control terminal of the fifth transistor and the ground terminal.

[0019] The following benefits can be obtained by adopting this technical solution: (1) The drive control unit directly drives the power switch unit, without the main control circuit directly participating in the drive signal control. It occupies fewer pin resources of the main control unit, has strong anti-interference ability, and improves the reliability of the system.

[0020] (2) Set up a zero-crossing detection unit to accurately detect the zero-crossing point of the AC signal and feed it back to the main control circuit. This is used to provide the power grid synchronization signal, reduce surge current, achieve "soft start" and reduce interference, protect the switching power supply unit, and determine the working recovery time of the drive control circuit after the fault is recovered.

[0021] (3) The first comparator module and the second comparator module respectively monitor the voltage at the center tap on the primary side of the transformer unit and the voltage at both ends on the primary side of the transformer unit, thereby forming an input voltage clamp and realizing surge suppression, which improves the safety of the system.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0024] Figure 1 This is a structural principle block diagram of a high-frequency induction heating system provided in an embodiment of the present invention; Figure 2 yes Figure 1 Block diagram of the power supply circuit structure; Figure 3 yes Figure 1 Circuit diagram of the drive control circuit and the high-frequency sensing unit; Figure 4 yes Figure 1 Circuit diagram of the main control circuit and detection circuit; Figure 5 yes Figure 2 Circuit schematic diagram of the switching power supply unit.

[0025] The reference numerals in the attached figures are as follows: 10, drive control circuit; 11, signal input unit; 12, drive control unit; 13, power switch unit; 20, power supply circuit; 21, switching power supply unit; 211, zero-crossing detection unit; 212, first rectifier bridge unit; 213, second rectifier bridge unit; 22, AC-DC conversion unit; 23, DC-DC conversion unit; 30, high-frequency induction unit; 31, transformer unit; 32, induction coil; 40, main control circuit; 41, main control unit; 42, electronic switch unit; 100, detection circuit; 50, first voltage acquisition unit; 51, first comparator module; 52, second comparator module; 60, second voltage acquisition unit; 70, first temperature acquisition unit; 80, second temperature acquisition unit; 90, control switch. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] Please see Figure 1-5 As shown, the present invention provides a high-frequency induction heating system, including: a drive control circuit 10, a power supply circuit 20, and a high-frequency induction unit 30. The drive control circuit 10 includes a signal input unit 11, a drive control unit 12, and a power switch unit 13. The high-frequency induction unit 30 includes a transformer unit 31 and an induction coil 32. The power supply circuit 20 has a first voltage terminal HV, a second voltage terminal +12V, and a third voltage terminal +5V. The drive control unit 12 has a first input terminal, a second input terminal, a first output terminal, and a second output terminal.

[0028] The first and second input terminals of the drive control unit 12 are respectively connected to the first terminal of the corresponding signal input unit 11. The first and second output terminals of the drive control unit 12 are respectively connected to the control terminal of the corresponding power switch unit 13. The center tap of the primary side of the transformer unit 31 is electrically connected to the first voltage terminal HV of the power supply circuit 20. The two ends of the primary side of the transformer unit 31 are respectively electrically connected to the first connection terminal of the corresponding power switch unit 13 and the second terminal of the corresponding signal input unit 11. The secondary side of the transformer unit 31 is electrically connected to the induction coil 32. The third terminal of the signal input unit 11 and the drive control unit 12 are respectively electrically connected to the second voltage terminal +12V of the power supply circuit 20. The second connection terminal of the power switch unit 13 is grounded.

[0029] The drive control unit 12 sends a PWM signal to the power switch unit 13 to make it work alternately. The transformer unit 31 inverts the DC power into high-frequency AC power. This high-frequency AC power generates a magnetic field in the induction coil 32, causing the induction coil 32 to induction heat the conductor workpiece located therein.

[0030] like Figure 4 As shown, the high-frequency induction heating system also includes a main control circuit 40. The drive control circuit 10 is electrically connected to the second voltage terminal +12V of the power supply circuit 20 through the main control circuit 40. The main control circuit 40 includes a main control unit 41 and an electronic switch unit 42. The second voltage terminal +12V of the power supply circuit 20 is electrically connected to the third terminal of the drive control unit 12 and the signal input unit 11 through the electronic switch unit 42. The main control unit 41 is electrically connected to the electronic switch unit 42 and the third voltage terminal +5V of the power supply circuit 20.

[0031] The voltages at the primary side of the transformer unit 31 are voltage VC and voltage VD, respectively. The signal input unit 11 and the power switch unit 13 are provided with two sets, one of which is electrically connected to voltage VC and the first input terminal of the drive control unit 12, and the other is electrically connected to voltage VD and the second input terminal of the drive control unit 12.

[0032] The following explanation uses the signal input unit 11 corresponding to voltage VC as an example. Figure 3 As shown, the signal input unit 11 includes a first resistor R6, a second resistor R5, a third resistor R4, a fourth resistor R3, a fifth resistor R15, a sixth resistor R16, a first transistor Q2, a second transistor Q6, a first capacitor C13, a first diode D6, and a second diode D13.

[0033] Resistors R6, R5, R4, and R3 are connected in series. One end of R6 is electrically connected to the primary voltage VC of transformer unit 31, and the other end of R3 is electrically connected to the output terminal 12V+ of electronic switch unit 42. Diodes D6 and D13 are connected in series. The cathode of D6 is electrically connected to the primary voltage VC of transformer unit 31, and the anode of D13 is electrically connected to the connection point between resistors R5 and R4. The connection point between the two transistors is electrically connected to the base of the first transistor Q2. The emitter of the first transistor Q2 is electrically connected to the output terminal 12V+ of the electronic switch unit 42. The collector of the first transistor Q2 is connected in series with the ground terminal by a fifth resistor R15. The collector of the first transistor Q2 is connected in series with the base of the second transistor Q6 by a first capacitor C13. The base of the second transistor Q6 is connected in series with the ground terminal by a sixth resistor R16. The emitter of the second transistor Q6 is grounded. The first and second input terminals of the drive control unit 12 are electrically connected to the collectors of the corresponding second transistors Q6. The power switch unit 13 consists of power switch transistors Q3 and Q4.

[0034] The drive control unit 12 utilizes the difference between the two signal input units 11 to cause one to turn on first. When the first capacitor C13 is charging, the second transistor Q6 is turned on, resulting in a low level at the first input terminal and the second output terminal of the drive control unit 12, and a high level at the first output terminal. At this time, the power switch Q3 is turned on, and the power switch Q4 is turned off. The first capacitor C13 is connected in series between the collector of the first transistor Q2 and the base of the second transistor Q6. The alternating high and low level inputs are achieved through the charging and discharging of the first capacitor C13 (capacitor C14).

[0035] The drive control unit 12 includes a drive chip U1, a seventh resistor (R10, R11), an eighth resistor (R14, R13), a ninth resistor (R9, R8), a tenth resistor (R12, R22), a second capacitor (C12, C11), a third diode (D10, D11), and a fourth diode (D5, D8).

[0036] The first and second input terminals of the driver chip U1 are electrically connected to the collectors of the corresponding second transistors (Q6 and Q5), respectively. The first input terminal of the driver chip U1 is connected in series with its first output terminal, and the second input terminal is connected in series with its second output terminal, respectively. The driver chip U1 is electrically connected to the output terminal 12V+ of the electronic switch unit 42. The first input terminal of the driver chip U1 is connected in series with its second output terminal, and the second input terminal is connected in series with its first output terminal, respectively. The first and second output terminals of the driver chip U1 are connected in series with the control terminals of the corresponding power switch unit 13, respectively. The two ends of the ninth resistor (R9 and R8) are connected in parallel with the third diode (D10 and D11). The control terminal of the power switch unit 13 is connected in series with the ground terminal with the tenth resistor (R12 and R22) and the fourth diode (D5 and D8) connected in parallel.

[0037] Taking the voltage VC as an example, the eighth resistor R14 and the second capacitor C12 form a compensation network to ensure the stability and reliability of the drive control unit 12.

[0038] like Figure 4 As shown, the electronic switch unit 42 includes a fourth transistor Q7, a fifth transistor Q8, a thirteenth resistor R21, a fourteenth resistor R24, a fifteenth resistor R29, a sixteenth resistor R30, a seventeenth resistor R31, a seventh diode D15, a fourth capacitor C9, and a fifth capacitor C6.

[0039] The first terminal of the fourth transistor Q7 is electrically connected to the second voltage terminal +12V of the power supply circuit 20. The second terminal of the fourth transistor Q7 is the output terminal of the electronic switch unit 42, i.e., 12V+. The second terminal of the fourth transistor Q7 is electrically connected to the third terminals of the drive control unit 12 and the signal input unit 11 respectively. The seventh diode D15 is connected in series between the first terminal and the second terminal of the fourth transistor Q7. The thirteenth resistor R21 is connected in series between the control terminal and the first terminal of the fourth transistor Q7. The fourteenth resistor R24, the fourth capacitor C9, and the fifth capacitor C6 are connected in parallel in series between the second terminal of the fourth transistor Q7 and the ground terminal. The fifteenth resistor R29 is connected in series between the control terminal of the fourth transistor Q7 and the first terminal of the fifth transistor Q8. The second terminal of the fifth transistor Q8 is grounded. The sixteenth resistor R30 is connected in series between the control terminal of the fifth transistor Q8 and the main control unit 41. The seventeenth resistor R31 is connected in series between the control terminal of the fifth transistor Q8 and the ground terminal.

[0040] When a system fault occurs (overtemperature, overvoltage), the main control unit 41 outputs a control signal to the electronic switch unit 42 to shut down the drive control circuit 10 by cutting off the power supply. The electronic switch unit 42 can realize functions such as soft start, standby or emergency stop, which increases the flexibility of system control.

[0041] The high-frequency induction heating system also includes a detection circuit 100, which includes a first voltage acquisition unit 50. The input terminal of the first voltage acquisition unit 50 is electrically connected to the two ends of the primary side of the transformer unit 31 and the center tap of the primary side of the transformer unit, respectively. The first voltage acquisition unit 50 is also electrically connected to the second voltage terminal +12V of the power supply circuit 20 and the main control unit 41, respectively.

[0042] The first voltage acquisition unit 50 includes a first comparator module 51, a second comparator module 52, and a third transistor Q13. The first input terminal of the first comparator module 51 is electrically connected to the first voltage terminal HV of the power supply circuit 20. The second input terminals of the first comparator module 51 and the second input terminal of the second comparator module 52 are electrically connected to the second voltage terminal +12V of the power supply circuit 20. The first input terminal of the second comparator module 52 is electrically connected to the voltages VC and VD at the primary side of the transformer unit 31. The output terminals of the first comparator module 51 and the second comparator module 52 are electrically connected to the second voltage terminal +12V of the power supply circuit 20. The output terminal of the first comparator module 51 is electrically connected to the control terminal of the third transistor Q13. The first connection terminal of the third transistor Q13 is grounded, and the second connection terminal of the third transistor Q13 is electrically connected to the main control unit 41.

[0043] When the first voltage acquisition unit 50 detects any one of the overvoltages VC, VD, or HV, the comparator output flips, triggering overvoltage protection. This provides high reliability and achieves rapid voltage threshold judgment at a low cost, meeting the speed requirements of protection response. It also clamps the input voltage of the transformer unit 31, filtering out high-frequency noise and suppressing surges. The main control unit 41 sends a control signal to the electronic switch unit 42 based on the trigger signal, causing it to cut off the 12V+ output, driving the control unit 12 and signal input unit 11 to shut down, and stopping the PWM output, thus achieving more reliable and faster software protection.

[0044] The detection circuit 100 also includes a second voltage acquisition unit 60, which is electrically connected to the first voltage terminal HV of the power supply circuit 20 and the main control unit 41, respectively.

[0045] The second voltage acquisition unit 60 includes an eighteenth resistor R19, a nineteenth resistor R27, a twentieth resistor R34, an adjustable resistor R25, a sixth transistor Q9, a sixth capacitor C17, and an inductor L1. The first terminal of the sixth transistor Q9 is electrically connected to the main control unit 41, and the second terminal of the sixth transistor Q9 is grounded. An adjustable resistor R25 is connected in series between the control terminal of the sixth transistor Q9 and the ground terminal. The sixth capacitor C17 and the twentieth resistor R34 are connected in parallel between the control terminal of the sixth transistor Q9 and its second terminal. The nineteenth resistor R27 and the eighteenth resistor R19 are connected in series between the control terminal of the sixth transistor Q9 and the first voltage terminal HV of the power supply circuit 20. The first voltage terminal HV of the power supply circuit 20 is connected to the inductor L1 to form the HV1 voltage terminal. The second voltage acquisition unit 60 is used to acquire the HV voltage. When the HV voltage exceeds the voltage threshold, the sixth transistor Q9 is turned on, triggering overvoltage protection. By setting an adjustable resistor R25, a voltage detection method with a variable voltage threshold is provided. Compared with the first comparator module 51 for acquiring the HV voltage, this method is more flexible and has a wider range of applications.

[0046] The high-frequency induction heating system also includes a heat sink for dissipating heat from at least one of the power switch unit 13 and the induction coil 32. The detection circuit 100 also includes a first temperature acquisition unit 70 for acquiring the temperature of the transformer unit 31, a second temperature acquisition unit 80 for acquiring the temperature of the heat sink corresponding to the power switch unit 13, and a control switch 90. The control switch 90, the first temperature acquisition unit 70, and the second temperature acquisition unit 80 are connected in series between the third voltage terminal +5V of the power supply circuit 20 and the ground terminal. The connection point between the second temperature acquisition unit 80 and the third voltage terminal +5V of the power supply circuit 20 is electrically connected to the main control unit 41.

[0047] Among them, the first temperature acquisition unit 70 and the second temperature acquisition unit 80 are temperature switches, which are connected in series through interface TS1 and interface TS2 respectively. As long as either the temperature switch or the control switch 90 is disconnected, the main control unit 41 can immediately detect and stop the machine, which is more reliable and can simultaneously monitor the temperature of the power switch unit 13 and the transformer unit 31.

[0048] The operating power of the detection circuit 100 mostly comes from the second voltage terminal +12V and the third voltage terminal +5V of the power supply circuit 20. This is a different voltage branch from the 12V+ output of the electronic switch unit 42. This ensures that the detection circuit 100 can continue to monitor the system status after the main control unit 41 turns off the power to the drive control circuit 10, avoiding the influence of power switch noise, and making the sampling more accurate. This provides the main control unit 41 with real-time data to determine whether the fault has been eliminated and whether the system can be restarted.

[0049] like Figure 2 ,5 As shown, the power supply circuit 20 includes a switching power supply unit 21, an AC-DC conversion unit 22, and a DC-DC conversion unit 23. The input terminal of the AC-DC conversion unit 22 is electrically connected to the AC power supply. The output terminal of the DC-DC conversion unit 23 forms the second voltage terminal +12V and the third voltage terminal +5V of the power supply circuit 20. The switching power supply unit 21 is electrically connected to the output terminal of the AC-DC conversion unit 22 and the DC-DC conversion unit 23, respectively. The switching power supply unit 21 includes a zero-crossing detection unit 211, a first rectifier bridge unit 212, and a second rectifier bridge unit 213. One end of the second rectifier bridge unit 213 is electrically connected to the main control unit 41 through the zero-crossing detection unit 211. The other end of the second rectifier bridge unit 213 is electrically connected to the first rectifier bridge unit 212 and the DC-DC conversion unit 23, respectively. One end of the first rectifier bridge unit 212 is electrically connected to the AC-DC conversion unit 22, and the other end of the first rectifier bridge unit 212 forms the first voltage terminal HV of the power supply circuit 20. The DC-DC conversion unit 23 is electrically connected to the main control unit 41 and the electronic switch unit 42, respectively. The AC-DC conversion unit 22 is electrically connected to the first rectifier bridge unit 212 through interface E, and the DC-DC conversion unit 23 is electrically connected to the second rectifier bridge unit 213 through interface M1.

[0050] The zero-crossing detection unit 211 includes a first optocoupler H1, a first switching transistor Q11, an eleventh resistor R47, a twelfth resistor R44, a third capacitor C25, a fifth diode D25, and a sixth diode D9.

[0051] The receiving end of the first optocoupler H1 is electrically connected to the main control unit 41. One end of the transmitting end of the first optocoupler H1 is connected in series with the first connection end of the first switching transistor Q11 by an eleventh resistor R47. The other end of the transmitting end of the first optocoupler H1 is connected in series with the control end of the first switching transistor Q11 by a twelfth resistor R44. The other end of the transmitting end of the first optocoupler H1 is connected in series with the second connection end of the first switching transistor Q11 by a fifth diode D25. The second connection end of the first switching transistor Q11 is connected in series with its control end by a sixth diode D9. The two ends of the fifth diode D25 are connected in parallel with a third capacitor C25. The two ends of the twelfth resistor R44 are electrically connected to one end of the second rectifier bridge 213.

[0052] After half-wave rectification by the sixth diode D9 and the third capacitor C25, the fifth diode D25 clamps the voltage. The pulsating DC of the second rectifier bridge unit 213 will cause the first switch Q11 to turn on or off, and the first optocoupler H1 will turn on or off accordingly. This allows the first switch Q11 to provide a more accurate drive signal, improve the zero-crossing acquisition accuracy, and enhance anti-interference capabilities. Zero-crossing detection is used to provide a grid synchronization signal, reduce inrush current, achieve "soft start," and reduce interference to protect the switching power supply unit 21 and determine the recovery timing of the drive control circuit 10 after the fault is recovered.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0054] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0055] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0056] For those skilled in the art, various changes and modifications will undoubtedly be apparent after reading the above description. Therefore, the appended claims should be construed as covering all changes and modifications that encompass the true intent and scope of the invention. Any and all equivalent scope and content within the scope of the claims should be considered to remain within the intent and scope of the invention.

Claims

1. A high-frequency induction heating system, characterized in that, include: The system includes a drive control circuit, a power supply circuit, and a high-frequency induction unit, with the high-frequency induction unit electrically connected to both the drive control circuit and the power supply circuit. The drive control circuit includes a signal input unit, a drive control unit, and a power switch unit. The high-frequency induction unit includes a transformer unit and an induction coil. The power supply circuit has a first voltage terminal and a second voltage terminal. The drive control unit has a first input terminal, a second input terminal, a first output terminal, and a second output terminal. The first and second input terminals of the drive control unit are respectively connected to the first terminals of the corresponding signal input units. The first and second output terminals of the drive control unit are respectively connected to the control terminals of the corresponding power switch units. The center tap on the primary side of the transformer unit is electrically connected to the first voltage terminal of the power supply circuit. The two ends on the primary side of the transformer unit are respectively electrically connected to the first connection terminal of the corresponding power switch unit and the second terminal of the corresponding signal input unit. The secondary side of the transformer unit is electrically connected to the induction coil. The third terminal of the signal input unit and the drive control unit are respectively electrically connected to the second voltage terminal of the power supply circuit. The second connection terminal of the power switch unit is grounded. The drive control unit sends a PWM signal to the power switch unit to make it work alternately. The transformer unit inverts DC power into high-frequency AC power, which generates a magnetic field in the induction coil, causing the induction coil to induction heat the conductor workpiece located therein.

2. The high-frequency induction heating system as described in claim 1, characterized in that: It also includes a main control circuit. The drive control circuit is electrically connected to the power supply circuit through the main control circuit. The main control circuit includes a main control unit and an electronic switch unit. The power supply circuit also has a third voltage terminal. The second voltage terminal of the power supply circuit is electrically connected to the third terminal of the drive control unit and the signal input unit through the electronic switch unit. The main control unit is electrically connected to the electronic switch unit and the third voltage terminal of the power supply circuit.

3. The high-frequency induction heating system as described in claim 2, characterized in that: It also includes a detection circuit, which includes a first voltage acquisition unit. The input terminal of the first voltage acquisition unit is electrically connected to both ends of the primary side of the transformer unit and the center tap of the primary side of the transformer unit, respectively. The first voltage acquisition unit is also electrically connected to the second voltage terminal of the power supply circuit and the main control unit, respectively.

4. The high-frequency induction heating system as described in claim 3, characterized in that: The detection circuit also includes a second voltage acquisition unit, which is electrically connected to the first voltage terminal of the power supply circuit and the main control unit, respectively.

5. The high-frequency induction heating system as described in any one of claims 2-4, characterized in that: The power supply circuit includes a switching power supply unit, an AC-DC conversion unit, and a DC-DC conversion unit. The input terminal of the AC-DC conversion unit is electrically connected to an AC power source, and the output terminal of the DC-DC conversion unit forms the second and third voltage terminals of the power supply circuit. The switching power supply unit is electrically connected to the output terminal of the AC-DC conversion unit and the DC-DC conversion unit, respectively. The switching power supply unit includes a zero-crossing detection unit, a first rectifier bridge unit, and a second rectifier bridge unit. One end of the second rectifier bridge unit is electrically connected to the main control unit through a zero-crossing detection unit, and the other end of the second rectifier bridge unit is electrically connected to the first rectifier bridge unit and the DC-DC conversion unit respectively. One end of the first rectifier bridge unit is electrically connected to the AC-DC conversion unit, and the other end of the first rectifier bridge unit forms the first voltage terminal of the power supply circuit. The DC-DC conversion unit is electrically connected to the main control unit and the electronic switch unit respectively.

6. The high-frequency induction heating system as described in claim 2, characterized in that: The signal input unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first transistor, a second transistor, a first capacitor, a first diode, and a second diode; After the first, second, third, and fourth resistors are connected in series, one end of the first resistor is electrically connected to the primary side of the transformer unit, and the other end of the fourth resistor is electrically connected to the electronic switch unit. After the first and second diodes are connected in series, the cathode of the first diode is electrically connected to the primary side of the transformer unit, the anode of the second diode is electrically connected to the connection point between the second and third resistors, the connection point between the third and fourth resistors is electrically connected to the base of the first transistor, the emitter of the first transistor is electrically connected to the electronic switch unit, the collector of the first transistor is connected in series with the ground terminal with a fifth resistor, the collector of the first transistor is connected in series with the base of the second transistor with a first capacitor, the base of the second transistor is connected in series with the ground terminal with a sixth resistor, the emitter of the second transistor is grounded, and the first and second input terminals of the drive control unit are respectively electrically connected to the collectors of the corresponding second transistors.

7. The high-frequency induction heating system as described in claim 6, characterized in that: The drive control unit includes a drive chip, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a second capacitor, a third diode, and a fourth diode; The first and second input terminals of the driver chip are electrically connected to the collectors of the corresponding second transistors. A seventh resistor is connected in series between the first input terminal and its first output terminal, and between the second input terminal and its second output terminal. The driver chip is electrically connected to the electronic switch unit. An eighth resistor and a second capacitor are connected in series between the first input terminal and its second output terminal, and between the second input terminal and its first output terminal. A ninth resistor is connected in series between the first and second output terminals of the driver chip and the control terminal of the corresponding power switch unit. A third diode is connected in parallel across the two ends of the ninth resistor. A tenth resistor and a fourth diode are connected in parallel between the control terminal and the ground terminal of the power switch unit.

8. The high-frequency induction heating system as described in claim 5, characterized in that: The zero-crossing detection unit includes a first optocoupler, a first switching transistor, an eleventh resistor, a twelfth resistor, a third capacitor, a fifth diode, and a sixth diode; The receiving end of the first optocoupler is electrically connected to the main control unit. An eleventh resistor is connected in series between one end of the transmitting end of the first optocoupler and the first connection end of the first switching transistor. A twelfth resistor is connected in series between the other end of the transmitting end of the first optocoupler and the control end of the first switching transistor. A fifth diode is connected in series between the other end of the transmitting end of the first optocoupler and the second connection end of the first switching transistor. A sixth diode is connected in series between the second connection end of the first switching transistor and its control end. A third capacitor is connected in parallel across the two ends of the fifth diode. The two ends of the twelfth resistor are electrically connected to one end of the second rectifier bridge.

9. The high-frequency induction heating system as described in claim 3, characterized in that: The first voltage acquisition unit includes a first comparator module, a second comparator module, and a third transistor; The first input terminal of the first comparator module is electrically connected to the first voltage terminal of the power supply circuit. The second input terminals of the first comparator module and the second input terminal of the second comparator module are electrically connected to the second voltage terminal of the power supply circuit. The first input terminal of the second comparator module is electrically connected to the two ends of the primary side of the transformer unit. The output terminals of the first comparator module and the second comparator module are electrically connected to the second voltage terminal of the power supply circuit. The output terminal of the first comparator module is electrically connected to the control terminal of the third transistor. The first connection terminal of the third transistor is grounded. The second connection terminal of the third transistor is electrically connected to the main control unit.

10. The high-frequency induction heating system according to any one of claims 2-4, 6, 7, and 9, characterized in that: The electronic switching unit includes a fourth transistor, a fifth transistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, a seventh diode, a fourth capacitor, and a fifth capacitor; The first terminal of the fourth transistor is electrically connected to the second voltage terminal of the power supply circuit. The second terminal of the fourth transistor is electrically connected to the third terminals of the drive control unit and the signal input unit, respectively. A seventh diode is connected in series between the first terminal and the second terminal of the fourth transistor. A thirteenth resistor is connected in series between the control terminal and the first terminal of the fourth transistor. A fourteenth resistor, a fourth capacitor, and a fifth capacitor are connected in parallel in series between the second terminal of the fourth transistor and the ground terminal. A fifteenth resistor is connected in series between the control terminal of the fourth transistor and the first terminal of the fifth transistor. The second terminal of the fifth transistor is grounded. A sixteenth resistor is connected in series between the control terminal of the fifth transistor and the main control unit. A seventeenth resistor is connected in series between the control terminal of the fifth transistor and the ground terminal.

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