High frequency arc starting circuit of welding machine and welding machine

Abstract

A high-frequency arc starting circuit of a welding machine and a welding machine. When receiving a trigger signal, the control circuit outputs a boost control signal of a second preset time after outputting a first pulse width modulation signal for a first preset time, and outputs a high-frequency control signal after outputting the boost control signal for a third preset time; the third preset time is less than or equal to the second preset time; the main loop circuit outputs a first direct current and a supply voltage according to the first pulse width modulation signal; the boost switch circuit switches the supply voltage according to the boost control signal; the boost circuit boosts the supply voltage to generate a double voltage; the high-frequency drive circuit outputs a high-frequency drive signal according to the high-frequency control signal; the high-frequency arc starting circuit converts the supply voltage into a high-voltage pulse according to the high-frequency drive signal; the arc starting coil realizes high-voltage arc starting by applying the high-voltage pulse received on the primary side to the double voltage received on the secondary side; the working efficiency and ease of use of the high-frequency arc starting circuit are improved.

Description

Technical Field

[0001] The present application belongs to the field of welding equipment, and in particular to a high-frequency arc starting circuit of a welding machine and a welding machine. Background Art

[0002] When the control switch of the welding gun is pressed, the high-frequency arc starting circuit of the traditional welding machine starts working, the gas valve opens, and the protective gas argon is provided to the welding gun. At the same time, a high-frequency high-voltage energy is output to the welding gun, thereby breaking through the air to generate an arc to ignite the main arc. When the main arc is ignited, the high-frequency arc starting signal can be turned off after sampling the main arc current. The whole process is mostly controlled by analog circuits. However, when the analog circuit controls the high-frequency arc starting, because it is impossible to achieve precise timing control, the high-frequency arc starting is released before the energy of the welding machine climbs to the maximum value. The arc starting often fails due to insufficient energy or the arc starts after releasing multiple high frequencies. This not only reduces the working efficiency of the high-frequency arc starting circuit of the welding machine, but also has poor usability.

[0003] Since the high-frequency arc starting circuit of the traditional welding machine cannot perform timing control, the working efficiency is low and the usability is poor. Summary of the invention

[0004] The purpose of the present application is to provide a high-frequency arc starting circuit for a welding machine and a welding machine, aiming to solve the problem of low working efficiency and poor usability of the high-frequency arc starting circuit of a traditional welding machine.

[0005] The embodiment of the present application provides a high-frequency arc starting circuit of a welding machine, comprising:

[0006] A control circuit configured to, when receiving a trigger signal, output a first pulse width modulation signal according to the trigger signal, and output a boost control signal of a second preset duration after outputting the first pulse width modulation signal for a first preset duration, and output a high-frequency control signal after outputting the boost control signal for a third preset duration; the third preset duration is less than or equal to the second preset duration;

[0007] A main loop circuit, connected to the control circuit, configured to convert the received input alternating current into a first direct current and a supply voltage according to the first pulse width modulation signal; wherein the first direct current is output from a positive lead terminal of the main loop circuit and a negative lead terminal of the main loop circuit;

[0008] a boost switch circuit, connected to the control circuit and configured to switch the supply voltage according to the boost control signal;

[0009] a high-frequency driving circuit, connected to the control circuit and configured to output a high-frequency driving signal according to the high-frequency control signal;

[0010] A high-frequency arc ignition circuit connected to the main loop circuit, the boost switch circuit and the high-frequency drive circuit, and configured to convert the supply voltage into a high-voltage pulse according to the high-frequency drive signal;

[0011] A boost circuit connected to the positive lead terminal of the main loop circuit, the negative lead terminal of the main loop circuit, the boost switch circuit and the high-frequency arc ignition circuit, and configured to boost the supply voltage to generate a doubled voltage;

[0012] An arc striking coil, wherein the primary side of the arc striking coil is connected to the high-frequency arc striking circuit, and the secondary side of the arc striking coil is connected in series between the negative lead terminal of the main loop circuit and the negative phase interface of the welding machine, and is configured to achieve high-voltage arc striking by applying the high-voltage pulse received on the primary side to the doubled voltage received on the secondary side.

[0013] In one of the embodiments, the control circuit is further configured to output a gas control signal according to the trigger signal before outputting the high-frequency control signal;

[0014] The high-frequency arc starting circuit also includes:

[0015] The gas switch circuit is connected to the control circuit and is configured to open the gas valve according to the gas control signal.

[0016] In one embodiment, the main loop circuit comprises:

[0017] a rectifier assembly configured to convert an input alternating current into a second direct current;

[0018] a PWM driving component connected to the control circuit and configured to output a second pulse width modulation signal according to the first pulse width modulation signal;

[0019] an inverter component, connected to the PWM drive component and the rectifier component, and configured to convert the second direct current into a first alternating current according to the second pulse width modulation signal;

[0020] a conversion component, connected to the inversion component, configured to perform voltage conversion on the first alternating current to generate the supply voltage and a second alternating current;

[0021] The rectifying and filtering component is connected to the conversion component and is configured to rectify and filter the second alternating current to output the first direct current.

[0022] In one embodiment, the main loop circuit further includes:

[0023] a sampling component, connected to the inversion component and the conversion component, and configured to detect the first alternating current to generate a sampling voltage;

[0024] The control circuit is further configured to output the first pulse width modulation signal according to the sampled voltage.

[0025] In one embodiment, the boost switch circuit includes a relay, a first transistor, a first diode and a first resistor;

[0026] The normally open contact of the relay is the power supply voltage input terminal of the boost switch circuit, the common terminal of the relay is the power supply voltage output terminal of the boost switch circuit, the first end of the coil of the relay is connected to the negative electrode of the first transistor and the first power supply, the second end of the coil of the relay is connected to the positive electrode of the first transistor and the collector of the first transistor, the base of the first transistor is connected to the first end of the first resistor, the emitter of the first transistor is connected to the power ground, and the second end of the first resistor R1 is the boost control signal input terminal of the boost switch circuit.

[0027] In one embodiment, the high-frequency driving circuit includes a photocoupler, a first field effect transistor, a second triode, a second diode, a third diode, a second resistor, a third resistor and a fourth resistor;

[0028] The positive electrode of the photoelectric coupler is connected to the first end of the second resistor and the negative electrode of the second diode, the second end of the second resistor is connected to the second power supply, the negative electrode of the photoelectric coupler is connected to the collector of the second transistor and the positive electrode of the second diode, the base of the second transistor is the high-frequency control signal input end of the high-frequency drive circuit, the collector of the photoelectric coupler is connected to the negative electrode of the third diode, the positive electrode of the third diode is the power supply voltage input end of the high-frequency drive circuit, the emitter of the photoelectric coupler is connected to the first end of the third resistor and the first end of the fourth resistor, the second end of the third resistor is connected to the gate of the first field effect transistor, the source of the first field effect transistor and the drain of the first field effect transistor together constitute the high-frequency drive signal output end of the high-frequency drive circuit, and the emitter of the second transistor is connected to the power ground.

[0029] In one embodiment, the high-frequency arc ignition circuit includes a discharge nozzle, a first transformer, a fourth diode, a fifth diode, a sixth diode, a seventh diode, an eighth diode and a first capacitor;

[0030] The cathodes of the four diodes, the cathode of the fifth diode, the anode of the sixth diode and the anode of the seventh diode together constitute the high-frequency driving signal input end of the high-frequency arc ignition circuit; the anodes of the four diodes, the cathode of the sixth diode and the first end of the primary winding of the first transformer together constitute the power supply voltage input end of the high-frequency arc ignition circuit; the anode of the fifth diode is connected to the cathode of the seventh diode and the second end of the primary winding of the first transformer; the first end of the secondary winding of the first transformer is connected to the anode of the eighth diode; the cathode of the eighth diode, the first end of the discharge nozzle and the first end of the first capacitor are the high-voltage pulse output ends of the high-frequency arc ignition circuit; the second end of the secondary winding of the first transformer is connected to the second end of the first capacitor and the second end of the discharge nozzle.

[0031] In one embodiment, the boost circuit includes a ninth diode, a tenth diode, a second capacitor, and a third capacitor;

[0032] The anode of the ninth diode, the cathode of the tenth diode, the first end of the second capacitor and the first end of the third capacitor together constitute the power supply voltage input end of the boost circuit, and the cathode of the ninth diode, the anode of the tenth diode, the second end of the second capacitor and the second end of the third capacitor together constitute the voltage doubling output end of the boost circuit.

[0033] In one embodiment, the control circuit includes a microprocessor, a Darlington transistor driver chip, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor;

[0034] The first data input and output terminal of the microprocessor is the trigger signal input terminal of the control circuit, the second data input and output terminal of the microprocessor is the first pulse width modulation signal output terminal of the control circuit, the second data input and output terminal of the microprocessor is the sampling signal input terminal of the control circuit, the third data input and output terminal of the microprocessor is connected to the first end of the fifth resistor and the first input terminal of the Darlington tube driver chip, the fourth data input and output terminal of the microprocessor is connected to the first end of the sixth resistor and the second input terminal of the Darlington tube driver chip, the fifth data input and output terminal of the microprocessor is connected to the first end of the seventh resistor and the third input terminal of the Darlington tube driver chip, the sixth data input and output terminal of the microprocessor is connected to the first end of the seventh resistor and the third input terminal of the Darlington tube driver chip, The first end of the eight resistors is connected to the fourth input end of the Darlington tube driver chip, the first output end of the Darlington tube driver chip is the gas control signal output end of the control circuit, the second output end of the Darlington tube driver chip is the first pulse width modulation signal output end of the control circuit, the third output end of the Darlington tube driver chip is the boost control signal output end of the control circuit, the fourth output end of the Darlington tube driver chip is the high-frequency control signal output end of the control circuit, the second end of the fifth resistor is connected to the third power supply, the collector common end of the Darlington tube driver chip is connected to the fourth power supply, and the ground end of the Darlington tube driver chip, the second end of the sixth resistor, the second end of the seventh resistor and the second end of the eighth resistor are connected to the power ground.

[0035] The embodiment of the present invention further provides a welding machine, the welding machine having the high-frequency arc starting circuit and the welding machine interface;

[0036] The welding machine interface comprises a welding machine positive phase interface and a welding machine negative phase interface, wherein the welding machine positive phase interface is connected to the positive lead terminal of the main loop circuit, and the welding machine negative phase interface is connected to the second end of the secondary side of the arc initiation coil.

[0037] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: since the control circuit outputs a boost control signal of a second preset duration after outputting the first pulse width modulation signal for a first preset duration, and outputs a high-frequency control signal after outputting the boost control signal for a third preset duration; the third preset duration is less than or equal to the second preset duration; after outputting the boost control signal for the third preset duration, that is, after the doubled voltage output by the boost circuit reaches a maximum value, a high-frequency control signal is output to control arc striking, and the energy for arc striking is sufficient, and the high-frequency arc striking circuit only needs to output a high-frequency pulse once to successfully strike the arc, and the arc striking is fast and stable, thereby improving the working efficiency and ease of use of the high-frequency arc striking circuit, and improving the working efficiency and user experience of the welder. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical invention in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 A schematic diagram of a high-frequency arc starting circuit of a welding machine provided in one embodiment of the present application;

[0040] Figure 2 Another structural schematic diagram of a high-frequency arc starting circuit of a welding machine provided in one embodiment of the present application;

[0041] Figure 3 A structural schematic diagram of a main loop circuit in a high-frequency arc starting circuit of a welding machine provided in one embodiment of the present application;

[0042] Figure 4 Another structural schematic diagram of a main loop circuit in a high-frequency arc starting circuit of a welding machine provided in one embodiment of the present application;

[0043] Figure 5 An exemplary circuit diagram of a high-frequency arc starting circuit of a welding machine provided in one embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0045] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0046] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0047] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0048] Figure 1 The schematic diagram of the structure of the high-frequency arc starting circuit of the welding machine provided by the preferred embodiment of the present application is shown. For the convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0049] The high-frequency arc starting circuit of the welding machine comprises a control circuit 11, a main loop circuit 12, a boost switch circuit 13, a boost circuit 14, a high-frequency drive circuit 15, a high-frequency arc starting circuit 16 and an arc starting coil T0.

[0050] The control circuit 11 is configured to output a first pulse width modulation signal according to the trigger signal when receiving a trigger signal, and output a boost control signal of a second preset duration after outputting the first pulse width modulation signal for a first preset duration, and output a high-frequency control signal after outputting the boost control signal for a third preset duration; the third preset duration is less than or equal to the second preset duration.

[0051] The main loop circuit 12 is connected to the control circuit 11 and is configured to convert the received input alternating current into a first direct current and a supply voltage according to a first pulse width modulation signal; wherein the first direct current is output from a positive lead terminal of the main loop circuit 12 and a negative lead terminal of the main loop circuit 12.

[0052] The boost switch circuit 13 is connected to the control circuit 11 and is configured to switch the supply voltage according to the boost control signal.

[0053] The boost circuit 14 is connected to the positive lead terminal of the main circuit 12, the negative lead terminal of the main circuit 12, the boost switch circuit 13 and the high-frequency arc ignition circuit 16, and is configured to boost the supply voltage to generate a doubled voltage.

[0054] The high-frequency driving circuit 15 is connected to the control circuit 11 and is configured to output a high-frequency driving signal according to the high-frequency control signal.

[0055] The high-frequency arc ignition circuit 16 is connected to the main loop circuit 12, the boost switch circuit 13 and the high-frequency drive circuit 15, and is configured to convert the supply voltage into a high-voltage pulse according to the high-frequency drive signal.

[0056] The arc striking coil T0 has its primary side connected to the high-frequency arc striking circuit 16, and its secondary side is connected in series between the negative lead terminal of the main loop circuit 12 and the negative phase interface of the welding machine, and is configured to achieve high-voltage arc striking by applying the high-voltage pulse received on the primary side to the doubled voltage received on the secondary side.

[0057] In a specific implementation, the trigger signal may be a key-on signal, the main loop circuit 12 may be an AC / DC conversion circuit, the boost circuit 14 may be a voltage doubling circuit, and the high-frequency drive circuit 15 may be an optocoupler isolation circuit.

[0058] As an example and not a limitation, the control circuit 11 is further configured to output a gas control signal according to a trigger signal before outputting a high-frequency control signal; Figure 2 As shown, the high frequency arc starting circuit also includes a gas switch circuit 17;

[0059] The gas switch circuit 17 is connected to the control circuit 11 and is configured to open the gas valve according to the gas control signal.

[0060] The gas switch circuit 17 opens the gas valve according to the gas control signal to provide the welding gun with protective gas argon.

[0061] like Figure 3 As shown, the main loop circuit 12 includes a rectifying component 121 , an inverting component 122 , a converting component 123 , a rectifying and filtering component 124 and a PWM driving component 125 .

[0062] The rectifier assembly 121 is configured to convert the input alternating current into a second direct current.

[0063] The pulse width modulation (PWM) driving component 125 is connected to the control circuit 11 and is configured to output a second pulse width modulation signal according to the first pulse width modulation signal.

[0064] The inverter component 122 is connected to the PWM driving component 125 and the rectifying component 121 , and is configured to convert the second direct current into the first alternating current according to the second pulse width modulation signal.

[0065] The conversion component 123 is connected to the inverter component 122 and is configured to perform voltage conversion on the first alternating current to generate a supply voltage and a second alternating current.

[0066] The rectifying and filtering component 124 is connected to the converting component 123 and is configured to rectify and filter the second alternating current to output a first direct current.

[0067] Through the configuration of the main loop circuit 12, the main loop circuit 12 can convert the received input AC power into the first DC power and the supply voltage according to the set first pulse width modulation signal, thereby obtaining the first DC power of the preset voltage.

[0068] like Figure 4 As shown, the main loop circuit 12 further includes a sampling component 126 .

[0069] The sampling component 126 is connected to the inverter component 122 and the conversion component 123 and is configured to detect the first alternating current to generate a sampling voltage;

[0070] The control circuit 11 is further configured to output a first pulse width modulation signal according to the sampled voltage.

[0071] The first alternating current is detected by the sampling component 126 to generate a sampling voltage to generate a negative feedback signal of the main loop circuit 12, thereby improving the stability of the first direct current.

[0072] Figure 5 An exemplary circuit structure of a high-frequency arc starting circuit of a welding machine provided by an embodiment of the present invention is shown. For the sake of convenience, only the part related to the embodiment of the present invention is shown, which is described in detail as follows:

[0073] The boost switch circuit 13 includes a relay K1 , a first transistor Q1 , a first diode D1 , and a first resistor R1 .

[0074] The normally open contact of relay K1 is the power supply voltage input terminal of the boost switch circuit 13, the common terminal of relay K1 is the power supply voltage output terminal of the boost switch circuit 13, the first end of the coil of relay K1 is connected to the negative electrode of the first transistor Q1 and the first power supply VAA, the second end of the coil of relay K2 is connected to the positive electrode of the first transistor Q1 and the collector of the first transistor Q1, the base of the first transistor Q1 is connected to the first end of the first resistor R1, the emitter of the first transistor Q1 is connected to the power ground, and the second end of the first resistor R1 is the boost control signal input terminal of the boost switch circuit 13.

[0075] The boost switch circuit 13 uses a very low voltage boost control signal to drive an electromagnet to drive a load component (such as a switch or a contact piece) and let the contact piece carry a large current supply voltage, thereby playing the role of circuit conversion and safety protection.

[0076] The high frequency driving circuit 15 includes a photocoupler U1 , a first field effect transistor M1 , a second transistor Q2 , a second diode D2 , a third diode D3 , a second resistor R2 , a third resistor R3 , and a fourth resistor R4 .

[0077] The positive electrode of the photoelectric coupler U1 is connected to the first end of the second resistor R2 and the negative electrode of the second diode D2, the second end of the second resistor R2 is connected to the second power supply VBB, the negative electrode of the photoelectric coupler U1 is connected to the collector of the second transistor Q2 and the positive electrode of the second diode D2, the base of the second transistor Q2 is the high-frequency control signal input end of the high-frequency drive circuit 15, the collector of the photoelectric coupler U1 is connected to the negative electrode of the third diode D3, the positive electrode of the third diode D3 is the power supply voltage input end of the high-frequency drive circuit 15, the emitter of the photoelectric coupler U1 is connected to the first end of the third resistor R3 and the first end of the fourth resistor R4, the second end of the third resistor R3 is connected to the gate of the first field effect transistor M1, the source of the first field effect transistor M1 and the drain of the first field effect transistor M1 together constitute the high-frequency drive signal output end of the high-frequency drive circuit 15, and the emitter of the second transistor Q2 is connected to the power ground.

[0078] The high-frequency driving circuit 15 achieves signal isolation and driving through the photocoupler U1 and the first field effect transistor M1.

[0079] The high-frequency arc ignition circuit 16 includes a discharge nozzle FD, a first transformer T1, a fourth diode D4, a fifth diode D5, a sixth diode D6, a seventh diode D7, an eighth diode D8 and a first capacitor C1.

[0080] The cathode of the fourth diode D4, the cathode of the fifth diode D5, the anode of the sixth diode D6 and the anode of the seventh diode D7 together constitute the high-frequency driving signal input end of the high-frequency arc ignition circuit 16, the anode of the fourth diode D4, the cathode of the sixth diode D6 and the first end of the primary winding of the first transformer T1 together constitute the power supply voltage input end of the high-frequency arc ignition circuit 16, the anode of the fifth diode D5 is connected to the cathode of the seventh diode D7 and the second end of the primary winding of the first transformer T1, the first end of the secondary winding of the first transformer T1 is connected to the anode of the eighth diode D8, the cathode of the eighth diode D8, the first end of the discharge nozzle FD and the first end of the first capacitor C1 are the high-voltage pulse output ends of the high-frequency arc ignition circuit 16, and the second end of the secondary winding of the first transformer T1 is connected to the second end of the first capacitor C1 and the second end of the discharge nozzle FD.

[0081] The high-frequency arc starting circuit 16 generates a high-voltage pulse, thereby providing a reliable arc starting signal for arc starting, thereby improving the reliability of the high-frequency arc starting circuit of the welding machine.

[0082] The boost circuit 14 includes a ninth diode D9, a tenth diode D10, a second capacitor C2 and a third capacitor C3.

[0083] The anode of the ninth diode D9, the cathode of the tenth diode D10, the first end of the second capacitor C2 and the first end of the third capacitor C3 together constitute the power supply voltage input end of the boost circuit 14, and the cathode of the ninth diode D9, the anode of the tenth diode D10, the second end of the second capacitor C2 and the second end of the third capacitor C3 together constitute the voltage doubling output end of the boost circuit 14.

[0084] The boost circuit 14 doubles the supply voltage, thereby increasing the arc striking voltage, and improving the arc striking efficiency and usability.

[0085] The control circuit 11 includes a microprocessor U2 , a Darlington transistor driving chip U3 , a fifth resistor R5 , a sixth resistor R6 , a seventh resistor R7 and an eighth resistor R8 .

[0086] The first data input and output terminal PC5 of the microprocessor U2 is the trigger signal input terminal of the control circuit 11, the second data input and output terminal PC6 of the microprocessor U2 is the first pulse width modulation signal output terminal of the control circuit 11, the second data input and output terminal PC6 of the microprocessor U2 is the sampling signal input terminal of the control circuit 11, the third data input and output terminal PC7 of the microprocessor U2 is connected to the first end of the fifth resistor R5 and the first input terminal IN6 of the Darlington tube driver chip U3, the fourth data input and output terminal PC8 of the microprocessor U2 is connected to the first end of the sixth resistor R6 and the second input terminal IN5 of the Darlington tube driver chip U3, the fifth data input and output terminal PC9 of the microprocessor U2 is connected to the first end of the seventh resistor R7 and the third input terminal IN4 of the Darlington tube driver chip U3, the sixth data input and output terminal PC10 of the microprocessor U2 is connected to the eighth resistor R5 and the second input terminal IN6 of the Darlington tube driver chip U3, A first end of the resistor R8 is connected to the fourth input end IN3 of the Darlington tube driver chip U3, a first output end OUT6 of the Darlington tube driver chip U3 is a gas control signal output end of the control circuit 11, a second output end OUT5 of the Darlington tube driver chip U3 is a first pulse width modulation signal output end of the control circuit 11, a third output end OUT4 of the Darlington tube driver chip U3 is a boost control signal output end of the control circuit 11, a fourth output end OUT3 of the Darlington tube driver chip U3 is a high-frequency control signal output end of the control circuit 11, a second end of the fifth resistor R5 is connected to the third power supply VCC, a collector common end COM of the Darlington tube driver chip U3 is connected to the fourth power supply VDD, a ground end GND of the Darlington tube driver chip U3, a second end of the sixth resistor R6, a second end of the seventh resistor R7 and a second end of the eighth resistor R8 are connected to the power ground.

[0087] The microprocessor U2 improves the accuracy of the timing control of the control signal required by the high-frequency arc starting circuit of the welding machine, and the Darlington tube driver chip U3 converts the control signal level, thereby achieving level matching between various functional modules of the high-frequency arc starting circuit of the welding machine.

[0088] The following is a combination of working principles Figure 5 As shown for further explanation:

[0089] When the first data input-output terminal PC5 of the microprocessor U2 receives a trigger signal, the microprocessor U2 outputs a gas control signal from the third data input-output terminal PC7 of the microprocessor U2 according to the trigger signal and outputs the gas control signal from the first output terminal OUT6 of the Darlington tube driver chip U3 after level conversion by the Darlington tube driver chip U3.

[0090] Then, the microprocessor U2 outputs a first pulse width modulation signal from the second data input and output terminal PC6 according to the trigger signal, and outputs a boost control signal of a second preset duration from the fifth data input and output terminal PC9 of the microprocessor U2 after outputting the first pulse width modulation signal for a first preset duration, and outputs the signal from the third output terminal OUT4 of the Darlington tube driver chip U3 after level conversion by the Darlington tube driver chip U3, and finally, outputs a high-frequency control signal from the sixth data input and output terminal PC10 of the microprocessor U2 after outputting the boost control signal for a third preset duration, and outputs the signal from the fourth output terminal OUT3 of the Darlington tube driver chip U3 after level conversion by the Darlington tube driver chip U3; wherein, the third preset duration is less than or equal to the fourth preset duration.

[0091] The main loop circuit 12 converts the received input alternating current into a first direct current and a supply voltage according to the first pulse width modulation signal; wherein the first direct current is output from the positive lead terminal of the main loop circuit 12 and the negative lead terminal of the main loop circuit 12.

[0092] The first transistor Q1 amplifies the boost control signal, and the relay K1 switches the supply voltage according to the amplified boost control signal; the boost circuit 14 including the ninth diode D9, the tenth diode D10, the second capacitor C2 and the third capacitor C3 boosts the supply voltage to generate a doubled voltage.

[0093] The second transistor Q2 amplifies the high-frequency control signal, the photocoupler U2 isolates the amplified high-frequency control signal, and the first field effect transistor M1 converts the isolated high-frequency control signal into a high-frequency driving signal.

[0094] The fourth diode D4, the fifth diode D5, the sixth diode D6 and the seventh diode D7 convert the power supply voltage according to the high-frequency driving signal, the first transformer T1 boosts the converted power supply voltage, and the boosted power supply voltage charges the first capacitor C1. When the voltage across the positive and negative electrodes of the first capacitor C1 is greater than the threshold, the discharge nozzle FD discharges to form a high-voltage pulse and outputs it to the primary side of the arc striking coil T0. The arc striking coil T0 realizes high-voltage arc striking by applying the high-voltage pulse received on the primary side to the doubled voltage received on the secondary side.

[0095] An embodiment of the present invention further provides a welding machine, comprising the first USB interface and the high-frequency arc starting circuit of the welding machine as described above; the first USB interface is configured to transfer the second USB3.0 signal.

[0096] The embodiment of the present invention outputs a first pulse width modulation signal according to the trigger signal through a control circuit when receiving a trigger signal, and outputs a boost control signal of a second preset time after outputting the first pulse width modulation signal for a first preset time, and outputs a high-frequency control signal after outputting the boost control signal for a third preset time; the third preset time is less than or equal to the second preset time; the main loop circuit converts the received input alternating current into a first direct current and a supply voltage according to the first pulse width modulation signal; wherein the first direct current is output from the positive lead terminal of the main loop circuit and the negative lead terminal of the main loop circuit; the boost switch circuit transfers the supply voltage according to the boost control signal; the boost circuit applies a high-frequency control signal to the supply voltage The voltage is boosted to generate a double voltage; the high-frequency driving circuit outputs a high-frequency driving signal according to the high-frequency control signal; the high-frequency arc starting circuit converts the supply voltage into a high-voltage pulse according to the high-frequency driving signal; the arc starting coil applies the high-voltage pulse received on the primary side to the double voltage received on the secondary side to achieve high-voltage arc starting; because the high-frequency control signal is output to control the arc starting after the third preset time of the boost control signal is output, that is, the double voltage output by the boost circuit reaches the maximum value, the energy for arc starting is sufficient, and the high-frequency arc starting circuit only needs to output a high-frequency pulse once to successfully start the arc, and the arc starting is fast and stable, which improves the working efficiency and ease of use of the high-frequency arc starting circuit, and improves the working efficiency and user experience of the welder.

[0097] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0098] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A high-frequency arc starting circuit for a welding machine, characterized in that: include: A control circuit configured to, when receiving a trigger signal, output a first pulse width modulation signal according to the trigger signal, and output a boost control signal of a second preset duration after outputting the first pulse width modulation signal for a first preset duration, and output a high-frequency control signal after outputting the boost control signal for a third preset duration; the third preset duration is less than or equal to the second preset duration; A main loop circuit, connected to the control circuit, configured to convert the received input alternating current into a first direct current and a supply voltage according to the first pulse width modulation signal; wherein the first direct current is output from a positive lead terminal of the main loop circuit and a negative lead terminal of the main loop circuit; A boost switch circuit, connected to the control circuit and configured to switch the supply voltage according to the boost control signal; a high-frequency driving circuit, connected to the control circuit and configured to output a high-frequency driving signal according to the high-frequency control signal; A high-frequency arc ignition circuit connected to the main loop circuit, the boost switch circuit and the high-frequency drive circuit, and configured to convert the supply voltage into a high-voltage pulse according to the high-frequency drive signal; A boost circuit connected to the positive lead terminal of the main loop circuit, the negative lead terminal of the main loop circuit, the boost switch circuit and the high-frequency arc ignition circuit, and configured to boost the supply voltage to generate a doubled voltage; An arc striking coil, wherein the primary side of the arc striking coil is connected to the high-frequency arc striking circuit, and the secondary side of the arc striking coil is connected in series between the negative lead terminal of the main loop circuit and the negative phase interface of the welding machine, and is configured to achieve high-voltage arc striking by applying the high-voltage pulse received on the primary side to the doubled voltage received on the secondary side.

2. The high-frequency arc starting circuit of a welding machine as claimed in claim 1, characterized in that: The control circuit is further configured to output a gas control signal according to the trigger signal before outputting the high-frequency control signal; The high-frequency arc starting circuit also includes: The gas switch circuit is connected to the control circuit and is configured to open the gas valve according to the gas control signal.

3. The high-frequency arc starting circuit of a welding machine as claimed in claim 1, characterized in that: The main loop circuit comprises: a rectifier assembly configured to convert an input alternating current into a second direct current; a PWM driving component connected to the control circuit and configured to output a second pulse width modulation signal according to the first pulse width modulation signal; an inverter component, connected to the PWM drive component and the rectifier component, and configured to convert the second direct current into a first alternating current according to the second pulse width modulation signal; a conversion component, connected to the inversion component, configured to perform voltage conversion on the first alternating current to generate the supply voltage and a second alternating current; The rectifying and filtering component is connected to the conversion component and is configured to rectify and filter the second alternating current to output the first direct current.

4. The high-frequency arc starting circuit of a welding machine as claimed in claim 3, characterized in that: The main loop circuit also includes: a sampling component, connected to the inversion component and the conversion component, and configured to detect the first alternating current to generate a sampling voltage; The control circuit is further configured to output the first pulse width modulation signal according to the sampled voltage.

5. The high-frequency arc starting circuit of a welding machine as claimed in claim 1, characterized in that: The boost switch circuit includes a relay, a first transistor, a first diode and a first resistor; The normally open contact of the relay is the power supply voltage input terminal of the boost switch circuit, the common terminal of the relay is the power supply voltage output terminal of the boost switch circuit, the first end of the coil of the relay is connected to the negative electrode of the first transistor and the first power supply, the second end of the coil of the relay is connected to the positive electrode of the first transistor and the collector of the first transistor, the base of the first transistor is connected to the first end of the first resistor, the emitter of the first transistor is connected to the power ground, and the second end of the first resistor is the boost control signal input terminal of the boost switch circuit.

6. The high-frequency arc starting circuit of a welding machine as claimed in claim 1, characterized in that: The high-frequency driving circuit includes a photocoupler, a first field effect transistor, a second triode, a second diode, a third diode, a second resistor, a third resistor and a fourth resistor; The positive electrode of the photoelectric coupler is connected to the first end of the second resistor and the negative electrode of the second diode, the second end of the second resistor is connected to the second power supply, the negative electrode of the photoelectric coupler is connected to the collector of the second transistor and the positive electrode of the second diode, the base of the second transistor is the high-frequency control signal input end of the high-frequency drive circuit, the collector of the photoelectric coupler is connected to the negative electrode of the third diode, the positive electrode of the third diode is the power supply voltage input end of the high-frequency drive circuit, the emitter of the photoelectric coupler is connected to the first end of the third resistor and the first end of the fourth resistor, the second end of the third resistor is connected to the gate of the first field effect transistor, the source of the first field effect transistor and the drain of the first field effect transistor together constitute the high-frequency drive signal output end of the high-frequency drive circuit, and the emitter of the second transistor is connected to the power ground.

7. The high frequency arc starting circuit of a welding machine as claimed in claim 1, characterized in that: The high-frequency arc ignition circuit includes a discharge nozzle, a first transformer, a fourth diode, a fifth diode, a sixth diode, a seventh diode, an eighth diode and a first capacitor; The cathodes of the four diodes, the cathode of the fifth diode, the anode of the sixth diode and the anode of the seventh diode together constitute the high-frequency driving signal input end of the high-frequency arc ignition circuit; the anodes of the four diodes, the cathode of the sixth diode and the first end of the primary winding of the first transformer together constitute the power supply voltage input end of the high-frequency arc ignition circuit; the anode of the fifth diode is connected to the cathode of the seventh diode and the second end of the primary winding of the first transformer; the first end of the secondary winding of the first transformer is connected to the anode of the eighth diode; the cathode of the eighth diode, the first end of the discharge nozzle and the first end of the first capacitor are the high-voltage pulse output ends of the high-frequency arc ignition circuit; the second end of the secondary winding of the first transformer is connected to the second end of the first capacitor and the second end of the discharge nozzle.

8. The high frequency arc starting circuit of a welding machine as claimed in claim 1, characterized in that: The boost circuit includes a ninth diode, a tenth diode, a second capacitor and a third capacitor; The anode of the ninth diode, the cathode of the tenth diode, the first end of the second capacitor and the first end of the third capacitor together constitute the power supply voltage input end of the boost circuit, and the cathode of the ninth diode, the anode of the tenth diode, the second end of the second capacitor and the second end of the third capacitor together constitute the voltage doubling output end of the boost circuit.

9. The high frequency arc starting circuit of a welding machine as claimed in claim 1, characterized in that: The control circuit includes a microprocessor, a Darlington transistor driver chip, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor; The first data input and output terminal of the microprocessor is the trigger signal input terminal of the control circuit, the second data input and output terminal of the microprocessor is the first pulse width modulation signal output terminal of the control circuit, the second data input and output terminal of the microprocessor is the sampling signal input terminal of the control circuit, the third data input and output terminal of the microprocessor is connected to the first end of the fifth resistor and the first input terminal of the Darlington tube driver chip, the fourth data input and output terminal of the microprocessor is connected to the first end of the sixth resistor and the second input terminal of the Darlington tube driver chip, the fifth data input and output terminal of the microprocessor is connected to the first end of the seventh resistor and the third input terminal of the Darlington tube driver chip, the sixth data input and output terminal of the microprocessor is connected to the first end of the seventh resistor and the third input terminal of the Darlington tube driver chip, The first end of the eight resistors is connected to the fourth input end of the Darlington tube driver chip, the first output end of the Darlington tube driver chip is the gas control signal output end of the control circuit, the second output end of the Darlington tube driver chip is the first pulse width modulation signal output end of the control circuit, the third output end of the Darlington tube driver chip is the boost control signal output end of the control circuit, the fourth output end of the Darlington tube driver chip is the high-frequency control signal output end of the control circuit, the second end of the fifth resistor is connected to the third power supply, the collector common end of the Darlington tube driver chip is connected to the fourth power supply, and the ground end of the Darlington tube driver chip, the second end of the sixth resistor, the second end of the seventh resistor and the second end of the eighth resistor are connected to the power ground.

10. A welding machine, characterized in that: The welding machine comprises: The high-frequency arc starting circuit and welding machine interface of a welding machine as claimed in any one of claims 1 to 9; The welding machine interface comprises a welding machine positive phase interface and a welding machine negative phase interface, wherein the welding machine positive phase interface is connected to the positive lead terminal of the main loop circuit, and the welding machine negative phase interface is connected to the second end of the secondary side of the arc initiation coil.

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