Intelligent high-frequency arc striking circuit

Abstract

The utility model discloses an intelligent high-frequency arc striking circuit, which comprises an MCU (Microprogrammed Control Unit), a charging control circuit, a discharging control circuit and a high-frequency inductor, the MCU is used for sending a charging control signal and a discharging control signal; the charging control circuit is connected with the MCU and is used for receiving and processing the charging control signal; the discharge control circuit is connected with the MCU and is used for receiving and processing the discharge control signal; a terminal 1 of the high-frequency inductor is connected with the charging control circuit, a terminal 2 of the high-frequency inductor is connected with the discharging control circuit, and terminals 3 and 4 of the high-frequency inductor are connected with an output main loop of an external electric welding machine. According to the utility model, the frequency and voltage control of the high-frequency and high-voltage arcing circuit can be adjusted, different working frequencies and working voltages can be selected according to different use conditions, high-frequency interference can be effectively reduced, and radiation damage to human bodies can be reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of the arc ignition circuit of argon arc welding machine, especially to an intelligent high-frequency arc ignition circuit. BACKGROUND

[0002] In the argon arc welding machine type, in order to improve work efficiency, the most conventional arc ignition mode is high-frequency high-voltage arc ignition, and the high-frequency high-voltage arc ignition will introduce strong electromagnetic interference at the same time of high efficiency, which will disturb the surrounding electrical products, and also cause strong interference to the argon arc welding machine itself. SUMMARY

[0003] According to the utility model embodiment, an intelligent high-frequency arc ignition circuit is provided, which comprises an MCU, a charging control circuit, a discharge control circuit and a high-frequency inductor.

[0004] The MCU is used to send charging control signals and discharge control signals.

[0005] The charging control circuit is connected with the MCU and is used to receive and process the charging control signals.

[0006] The discharge control circuit is connected with the MCU and is used to receive and process the discharge control signals.

[0007] The terminal 1 of the high-frequency inductor is connected with the charging control circuit, the terminal 2 of the high-frequency inductor is connected with the discharge control circuit, and the terminals 3 and 4 of the high-frequency inductor are connected with the output main loop of the external electric welding machine.

[0008] Further, the charging control circuit comprises a boost control chip, a first resistor, a first MOS tube, a second resistor, a third resistor, a first capacitor, a boost transformer, a first diode and a second capacitor.

[0009] The pin 1 of the boost control chip is connected with the MCU, the pin 6 of the boost control chip is connected with one end of the first resistor, and the pin 3 of the boost control chip is connected with one end of the second resistor.

[0010] The other end of the first resistor is connected with the gate of the first MOS tube.

[0011] The other end of the second resistor is connected with the source of the first MOS tube and one end of the third resistor.

[0012] The other end of the third resistor is grounded.

[0013] The drain of the first MOS tube is connected with the terminal 1 of the boost transformer.

[0014] The terminal 2 of the boost transformer is connected with the VCC port and grounded through the first capacitor, and the terminal HV of the boost transformer is connected with the anode of the first diode.

[0015] The negative electrode of the first diode is connected with the terminal 1 of the high-frequency inductor and one end of the second capacitor.

[0016] The other end of the second capacitor is connected with the terminal 3 of the step-up transformer and then grounded.

[0017] Further, the charging control circuit further comprises a third capacitor, one end of the third capacitor is connected between the pin 3 of the step-up control chip and one end of the second resistor, and the other end of the third capacitor is grounded.

[0018] Further, the charging control circuit further comprises a fourth resistor and a fourth capacitor.

[0019] One end of the fourth resistor is connected with the pin 8 of the step-up control chip.

[0020] One end of the fourth capacitor is connected with the pin 4 of the step-up control chip and the other end of the fourth resistor, and the other end of the fourth capacitor is grounded.

[0021] Further, the discharging control circuit comprises a fifth resistor, a second MOS tube, a bidirectional breakdown diode, an isolation driving transformer, a sixth resistor, a second diode, a thyristor and a hardware protection circuit.

[0022] One end of the fifth resistor is connected with the MCU.

[0023] The gate of the second MOS tube is connected with the other end of the fifth resistor, the source of the second MOS tube is grounded, the drain of the second MOS tube is connected with one end of the bidirectional breakdown diode and the terminal 2 of the isolation driving transformer.

[0024] The terminal 1 of the isolation driving transformer is connected with one end of the bidirectional breakdown diode and then connected with the VCC port, the terminal 3 of the isolation driving transformer is connected with one end of the sixth resistor, and the terminal 4 of the isolation driving transformer is grounded.

[0025] The other end of the sixth resistor is connected with the positive electrode of the second diode.

[0026] The negative electrode of the second diode is connected with the gate of the thyristor.

[0027] The cathode of the thyristor is grounded, and the anode of the thyristor is connected with the terminal 2 of the high-frequency inductor.

[0028] The hardware protection circuit is connected with the gate and the anode of the thyristor.

[0029] Further, the hardware protection circuit comprises a voltage stabilizing tube and a seventh resistor.

[0030] One end of the voltage stabilizing tube is connected with the anode of the thyristor.

[0031] One end of the seventh resistor is connected with one end of the voltage stabilizing tube, and the other end of the seventh resistor is connected between the gate of the thyristor and the negative electrode of the second diode.

[0032] Further, the discharge control circuit further comprises a third diode, a negative electrode of the third diode is connected between the sixth resistor and the second diode, and the other end of the third diode is grounded.

[0033] Further, the discharge control circuit further comprises an eighth resistor and a fifth capacitor.

[0034] One end of the eighth resistor is connected between the gate of the thyristor and the negative electrode of the second diode, and the other end of the eighth resistor is grounded.

[0035] One end of the fifth capacitor is connected between the one end of the eighth resistor and the gate of the thyristor, and the other end of the fifth capacitor is grounded.

[0036] Further, the discharge control circuit further comprises a ninth resistor, one end of the ninth resistor is connected between the other end of the fifth resistor and the gate of the second MOS tube, and the other end of the ninth resistor is connected to the source of the second MOS tube and then grounded.

[0037] The intelligent high-frequency arc striking circuit can adjust the frequency and voltage control of the high-frequency high-voltage arc striking circuit, select different working frequencies and working voltages according to different use cases, and effectively reduce high-frequency interference and reduce radiation damage to the human body.

[0038] It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the subject technology claimed. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 The circuit diagram of the intelligent high-frequency arc striking circuit according to the embodiment of the utility model. DETAILED DESCRIPTION

[0040] The preferred embodiments of the utility model will be described in detail below with reference to the drawings, and the utility model will be further described.

[0041] Firstly, the intelligent high-frequency arc striking circuit according to the embodiment of the utility model will be described. Figure 1 The intelligent high-frequency arc striking circuit according to the embodiment of the utility model is used for arc striking of argon arc welding, and has a wide application scenario.

[0042] As shown in the drawings, Figure 1 The intelligent high-frequency arc striking circuit according to the embodiment of the utility model comprises an MCU, a charging control circuit, a discharge control circuit and a high-frequency inductor TR2.

[0043] Specifically, as shown in the drawings, Figure 1 The MCU is used for sending a charging control signal and a discharge control signal.

[0044] Specifically, as shown in the drawings,Figure 1 As shown, the charging control circuit is connected with the MCU for receiving and processing the charging control signal. The charging control circuit comprises: a boost control chip U1, a first resistor R1, a first MOS tube T1, a second resistor R2, a third resistor R3, a first capacitor C3, a boost transformer TR1, a first diode D1 and a second capacitor C4. The pin 1 of the boost control chip U1 is connected with the MCU, the pin 6 of the boost control chip U1 is connected with one end of the first resistor R1, and the pin 3 of the boost control chip U1 is connected with one end of the second resistor R2. The other end of the first resistor R1 is connected with the gate of the first MOS tube T1, and the first resistor R1 is used for limiting the current flowing from the output pin of the boost control chip U1 to the first MOS tube T1, and also plays a certain impedance matching role, so that the output pin of the boost control chip U1 and the input stage (gate) of the first MOS tube T1 can work better together, ensure the effective transmission of the signal, and reduce the adverse effects such as signal reflection. The other end of the second resistor R2 is connected with the source of the first MOS tube T1 and one end of the third resistor R3. The other end of the third resistor R3 is grounded. The drain of the first MOS tube T1 is connected with the terminal 1 of the boost transformer TR1. The first MOS tube T1 serves as a switching element. When the OUT pin of the boost control chip U1 outputs a high-level signal, the gate-source voltage of the first MOS tube T1 is greater than its opening threshold voltage through the first resistor R1, and the first MOS tube T1 is turned on. At this time, the power supply supplies power to the primary winding of the boost transformer TR1 through the first MOS tube T1. When the OUT pin of the boost control chip U1 outputs a low-level signal, the gate-source voltage of the first MOS tube T1 is lower than the opening threshold voltage, and the first MOS tube T1 is cut off to stop supplying power to the boost transformer TR1. The first MOS tube T1 can also control a larger current to pass through the boost transformer TR1 to realize the conversion of electric energy, convert the input DC electric energy into high-frequency pulse electric energy, provide an input signal for the subsequent boost transformer TR1, and is one of the key elements for realizing the boost function. The terminal 2 of the boost transformer TR1 is connected with the VCC port and grounded through the first capacitor C3. The terminal HV of the boost transformer TR1 is connected with the anode of the first diode D1. The cathode of the first diode D1 is connected with the terminal 1 of the high-frequency inductor TR2 and one end of the second capacitor C4. The other end of the second capacitor C4 is connected with the terminal 3 of the boost transformer TR1 and then grounded.

[0045] Further, as shown in FIG. 2, the charging control circuit further comprises: a third capacitor C2, one end of the third capacitor C2 is connected between the pin 3 of the boost control chip U1 and one end of the second resistor R2, and the other end of the third capacitor C2 is grounded. The third capacitor C2 is used for filtering. Figure 1

[0046] Further, as shown in FIG. 2, the charging control circuit further comprises: a third capacitor C2, one end of the third capacitor C2 is connected between the pin 3 of the boost control chip U1 and one end of the second resistor R2, and the other end of the third capacitor C2 is grounded. The third capacitor C2 is used for filtering. Figure 1 ​As shown, the charging control circuit also includes: a fourth resistor R4 and a fourth capacitor C1; one end of the fourth resistor R4 is connected to pin 8 of the boost control chip U1; one end of the fourth capacitor C1 is connected to pin 4 of the boost control chip U1 and the other end of the fourth resistor R4, and the other end of the fourth capacitor C1 is grounded.

[0047] Specifically, such as Figure 1 As shown, the discharge control circuit is connected to the MCU and is used to receive and process the discharge control signal. The discharge control circuit includes: a fifth resistor R5, a second MOSFET Q1, a bidirectional breakdown diode Z2, an isolation drive transformer TR3, a sixth resistor R7, a second diode D3, a thyristor T2, and a hardware protection circuit. One end of the fifth resistor R5 is connected to the MCU and is mainly used to limit the discharge signal current to prevent excessive current from directly impacting the gate of the second MOSFET Q1 and damaging it. Simultaneously, it effectively transmits the discharge signal to the gate of the second MOSFET Q1 to control the conduction and cutoff states of the second MOSFET Q1. The gate of the second MOSFET Q1 is connected to the other end of the fifth resistor R5. The source of the second MOSFET Q1 is grounded, and the drain of the second MOSFET Q1 is connected to one end of the bidirectional breakdown diode Z2 and terminal 2 of the isolation drive transformer TR3. The circuit's on / off state is controlled according to the discharge control signal. When the discharge control signal turns on the second MOSFET Q1, it allows current to flow from the drain to the source, thereby realizing the conduction of the energy transfer path. Terminal 1 of the isolation drive transformer TR3 is connected to one end of the bidirectional breakdown diode Z2 and then to the VCC port. Terminal 3 of the isolation drive transformer TR3 is connected to one end of the sixth resistor R7. Terminal 4 of TR3 is grounded; the other end of the sixth resistor R7 is connected to the positive terminal of the second diode D3, which limits the current of the signal output from the isolation drive transformer TR3 to prevent excessive current from damaging the second diode D3 and subsequent components. At the same time, it also effectively transmits the signal after being transformed by the isolation drive transformer TR3 to the second diode D3, ensuring that the signal can be transmitted smoothly in the circuit; the negative terminal of the second diode D3 is connected to the gate of the thyristor T2; the cathode of the thyristor T2 is grounded, and the anode of the thyristor T2 is connected to terminal 2 of the high-frequency inductor TR2. When the discharge current in the primary of the high-frequency inductor TR2 is lower than the threshold, the thyristor T2 will automatically turn off to ensure that it only discharges once in one cycle and waits for the next charging cycle; the hardware protection circuit is connected to the gate and anode of the thyristor T2.

[0048] Furthermore, specifically, such as Figure 1As shown, the hardware protection circuit comprises: a Zener Z1 and a seventh resistor R8; one end of the Zener Z1 is connected to the anode of the thyristor T2; one end of the seventh resistor R8 is connected to one end of the Zener Z1, and the other end of the seventh resistor R8 is connected between the gate of the thyristor T2 and the negative electrode of the second diode D3. The hardware protection circuit is used to forcibly open T2 when the voltage on the capacitor exceeds the value of the Zener Z1, preventing the voltage from accumulating too high when the MCU control is wrong, and damaging the components.

[0049] Further, as shown in the figure, Figure 1 the discharge control circuit further comprises: a third diode D2, the negative electrode of the third diode D2 is connected between the sixth resistor R7 and the second diode D3, and the other end of the third diode D2 is grounded. The third diode D2 plays a clamping role, and when there is a too high positive voltage spike in the circuit, for example, a transient voltage generated during switching, the third diode D2 clamps the voltage at a lower level, protecting the second diode D3 and other subsequent components from damage from excessive voltage.

[0050] Further, as shown in the figure, Figure 1 the discharge control circuit further comprises: an eighth resistor R9 and a fifth capacitor C5; one end of the eighth resistor R9 is connected between the gate of the thyristor T2 and the negative electrode of the second diode D3, and the other end of the eighth resistor R9 is grounded; one end of the fifth capacitor C5 is connected between one end of the eighth resistor R9 and the gate of the thyristor T2, and the other end of the fifth capacitor C5 is grounded. The eighth resistor R9 and the fifth capacitor C5 are used for anti-interference and filtering.

[0051] Further, as shown in the figure, Figure 1 the discharge control circuit further comprises: a ninth resistor R6, one end of the ninth resistor R6 is connected between the other end of the fifth resistor R5 and the gate of the second MOS Q1, and the other end of the ninth resistor R6 is connected to the source of the second MOS Q1 and then grounded. The ninth resistor R6 provides a discharge path between the gate and the source of the second MOS Q1, which can quickly discharge the charge on the gate when the gate signal disappears, so that the second MOS Q1 can be reliably turned off. In addition, it can also form a voltage dividing circuit with the fifth resistor R5 to adjust the voltage at the gate of the second MOS Q1 to a certain extent, ensuring that the second MOS Q1 can be turned on and off according to the expected voltage threshold.

[0052] Specifically, as shown in the figure, Figure 1 terminal 1 of the high-frequency inductor TR2 is connected to the charging control circuit, terminal 2 of the high-frequency inductor TR2 is connected to the discharge control circuit, and terminals 3 and 4 of the high-frequency inductor TR2 are connected to the external electric welding machine output main circuit.

[0053] The charging control signal is a group of pulse signals, which is sent by the single-chip microcomputer, and the period (or frequency) of the charging is the frequency of the high frequency;

[0054] The discharging control signal is sent after the charging control signal, and the fixed time is determined by the desired high frequency strength.

[0055] For example:

[0056] When we first use the argon arc welding machine, the tungsten needle is cold at this time, and a higher success rate of arc striking is required at this time, and the high frequency performance is strong;

[0057] At this time, the charging control signal frequency can be set to 100Hz, that is, a period of 10ms, and after a period of charging, the voltage on the second capacitor C4 continuously rises, and at this time, the discharging control signal is sent, for example, after 25us of charging;

[0058] Immediately start discharging, at this time the voltage on the second capacitor C4 is about 1200V, after the high frequency inductor TR2, and after the voltage is boosted again, it is provided to the output main circuit of the electric welding machine.

[0059] After the machine is used for a short time, the tungsten needle is already relatively high in heat, and at this time, a relatively high arc striking voltage is not required to stabilize the arc, and at this time, the discharging can be started after 15us of charging, and at this time, the voltage on the second capacitor C4 is about 750V.

[0060] In this way, we can achieve different discharging voltages through time control.

[0061] When different arc striking frequencies are required, the charging control signal frequency can be changed.

[0062] The above, with reference to Figure 1 The intelligent high-frequency arc striking circuit according to the embodiments of the present application is described, the frequency and the voltage of the high-frequency high-voltage arc striking circuit can be controlled, different working frequencies and working voltages can be selected according to different use cases, and the high-frequency interference can be effectively reduced, and the radiation damage to the human body can be reduced.

[0063] It should be noted that in the present specification, the terms "comprise", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the elements defined by the statement "contain" do not exclude the presence of other identical elements in the process, method, article or equipment including the elements.

[0064] Although the content of the utility model has been introduced in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the utility model. After reading the above content, various modifications and substitutions of the utility model will be obvious to those skilled in the art. Therefore, the protection scope of the utility model should be limited by the attached claims.

Claims

1. An intelligent high-frequency arc-starting circuit, characterized in that, Includes: MCU, charging control circuit, discharging control circuit, and high-frequency inductor; The MCU is used to issue charging control signals and discharging control signals; The charging control circuit is connected to the MCU and is used to receive and process the charging control signal; The discharge control circuit is connected to the MCU and is used to receive and process the discharge control signal; Terminal 1 of the high-frequency inductor is connected to the charging control circuit, terminal 2 of the high-frequency inductor is connected to the discharging control circuit, and terminals 3 and 4 of the high-frequency inductor are connected to the external welding machine output main circuit.

2. The intelligent high-frequency arc-starting circuit as described in claim 1, characterized in that, The charging control circuit includes: a boost control chip, a first resistor, a first MOSFET, a second resistor, a third resistor, a first capacitor, a boost transformer, a first diode, and a second capacitor; Pin 1 of the boost control chip is connected to the MCU, pin 6 of the boost control chip is connected to one end of the first resistor, and pin 3 of the boost control chip is connected to one end of the second resistor. The other end of the first resistor is connected to the gate of the first MOS transistor; The other end of the second resistor is connected to the source of the first MOS transistor and one end of the third resistor; The other end of the third resistor is grounded; The drain of the first MOS transistor is connected to terminal 1 of the boost transformer; After terminal 2 of the step-up transformer is connected to the VCC port, it is grounded through the first capacitor. Terminal HV of the step-up transformer is connected to the positive terminal of the first diode. The negative terminal of the first diode is connected to terminal 1 of the high-frequency inductor and one end of the second capacitor; The other end of the second capacitor is connected to terminal 3 of the step-up transformer and then grounded.

3. The intelligent high-frequency arc-starting circuit as described in claim 2, characterized in that, The charging control circuit further includes a third capacitor, one end of which is connected between pin 3 of the boost control chip and one end of the second resistor, and the other end of the third capacitor is grounded.

4. The intelligent high-frequency arc-starting circuit as described in claim 2, characterized in that, The charging control circuit also includes: a fourth resistor and a fourth capacitor; One end of the fourth resistor is connected to pin 8 of the boost control chip; One end of the fourth capacitor is connected to pin 4 of the boost control chip and the other end of the fourth resistor, while the other end of the fourth capacitor is grounded.

5. The intelligent high-frequency arc-starting circuit as described in claim 1, characterized in that, The discharge control circuit includes: a fifth resistor, a second MOSFET, a bidirectional breakdown diode, an isolation drive transformer, a sixth resistor, a second diode, a thyristor, and a hardware protection circuit. One end of the fifth resistor is connected to the MCU; The gate of the second MOS transistor is connected to the other end of the fifth resistor, the source of the second MOS transistor is grounded, the drain of the second MOS transistor is connected to one end of the bidirectional breakdown diode and terminal 2 of the isolation drive transformer; Terminal 1 of the isolation drive transformer is connected to one end of the bidirectional breakdown diode and then connected to the VCC port. Terminal 3 of the isolation drive transformer is connected to one end of the sixth resistor, and terminal 4 of the isolation drive transformer is grounded. The other end of the sixth resistor is connected to the positive terminal of the second diode; The negative terminal of the second diode is connected to the gate of the thyristor; The cathode of the thyristor is grounded, and the anode of the thyristor is connected to terminal 2 of the high-frequency inductor. The hardware protection circuit is connected to the gate and anode of the thyristor.

6. The intelligent high-frequency arc-starting circuit as described in claim 5, characterized in that, The hardware protection circuit includes: a Zener diode and a seventh resistor; One end of the Zener diode is connected to the anode of the thyristor; One end of the seventh resistor is connected to one end of the Zener diode, and the other end of the seventh resistor is connected between the gate of the thyristor and the cathode of the second diode.

7. The intelligent high-frequency arc-starting circuit as described in claim 5, characterized in that, The discharge control circuit further includes a third diode, the negative terminal of which is connected between the sixth resistor and the second diode, and the other end of which is grounded.

8. The intelligent high-frequency arc-starting circuit as described in claim 5, characterized in that, The discharge control circuit also includes: an eighth resistor and a fifth capacitor; One end of the eighth resistor is connected between the gate of the thyristor and the cathode of the second diode, and the other end of the eighth resistor is grounded. One end of the fifth capacitor is connected between one end of the eighth resistor and the gate of the thyristor, and the other end of the fifth capacitor is grounded.

9. The intelligent high-frequency arc-starting circuit as described in claim 5, characterized in that, The discharge control circuit further includes: a ninth resistor, one end of which is connected between the other end of the fifth resistor and the gate of the second MOS transistor, and the other end of which is connected to the source of the second MOS transistor and then grounded.

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