CN214185674U - Digital welding machine control circuit with feedback and protection functions and digital welding machine - Google Patents

Abstract

The utility model belongs to the technical field of the welding machine, especially, relate to a digital welding machine control circuit with feedback and protect function, including welding machine input circuit, welding machine input circuit converts the alternating current of input into the direct current, still includes: the sampling output circuit is connected with the welding machine input circuit and samples the voltage output by the welding machine input circuit; the output control circuit is connected with the sampling output circuit and acquires the voltage sampled by the sampling output circuit; and the driving circuit is connected with the output control circuit and the input circuit of the welding machine. The utility model discloses realize the feedback and the regulatory function of the control circuit of electric welding in the use, guarantee the stability of the whole circuit of the control circuit of electric welding, promoted the welding efficiency of electric welding.

Description

Digital welding machine control circuit with feedback and protection functions and digital welding machine

Technical Field

The utility model belongs to the technical field of the electric welding, especially, relate to a digital welding machine control circuit and digital welding machine with feedback and protect function.

Background

With the continuous progress of digital signal processing technology and embedded systems, the field of welding power supplies is rapidly developed, and compared with the traditional welding machine, the digital welding machine has the advantages of high precision, good stability and easiness in control.

With the increasing functions of electric welding machines and the electric welding machines in the working environment of high voltage and heavy current, the stable operation of the system is an important requirement of a digital welding machine control circuit with feedback and protection functions. The welding defects can be caused by too large or too small current, for example, the defects of burnthrough, increased splashing, welding seam collapse, undercut, too large heat affected zone, large welding seam crystal grains, too large deformation after welding and the like are easily caused by the too large current, and the defects of incomplete penetration, poor fusion, too high welding seam residual height, easy slag inclusion, internal pores and the like are easily caused by the too small current.

At present, the control circuit of the electric welding machine on the market can only realize electric welding, but can not realize feedback control according to the feedback of the output current and voltage when electric welding, so that the condition that components and parts are damaged due to overlarge or undersize output voltage and current when electric welding is caused by no feedback control exists, and the problem of influencing electric welding efficiency is further generated. Therefore, it is necessary to design a digital welder control circuit with feedback and protection functions for preventing overcurrent.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a digital welding machine control circuit and digital welding machine with feedback and protect function aims at solving among the prior art because of there is not feedback control to make the technical problem who influences electric welding efficiency.

In order to achieve the above object, an embodiment of the present invention provides a digital welding machine control circuit with feedback and protection functions, including welding machine input circuit, the alternating current that welding machine input circuit will input is direct current for, still include:

the sampling output circuit is connected with the welding machine input circuit and samples the voltage output by the welding machine input circuit;

the output control circuit is connected with the sampling output circuit and acquires the voltage sampled by the sampling output circuit;

and the driving circuit is connected with the output control circuit and the input circuit of the welding machine.

Optionally, the output control circuit includes a digital signal processing circuit and a high-voltage board circuit, the high-voltage board circuit is connected to the input circuit of the welding machine and the sampling output circuit, and the digital signal processing circuit is connected to the high-voltage board circuit, the sampling output circuit and the driving circuit.

Optionally, the digital signal processing circuit comprises a welder main control chip, an MCU power circuit, an MCU driving circuit, a high-frequency circuit and a welder functional circuit; the welding machine main control chip is connected with the MCU power circuit, the MCU driving circuit, the high-frequency circuit and the welding machine functional circuit, the MCU power circuit is connected with the welding machine input circuit, the MCU driving circuit is connected with the driving circuit, and the high-frequency circuit is connected with the high-voltage board circuit.

Optionally, the MCU power circuit includes an MCU main power circuit, an MCU voltage stabilizing circuit, and a feedback circuit; the MCU main power circuit, the MCU voltage stabilizing circuit and the feedback circuit are all connected with the welding machine main control chip, the MCU main power circuit is connected with the welding machine input circuit, the MCU voltage stabilizing circuit is connected with the MCU main power circuit, and the feedback circuit is connected with the sampling output circuit.

Optionally, the MCU driving circuit includes a thirteenth operational amplifier and a digital-to-analog conversion connection port, the input end of the thirteenth operational amplifier is connected to the welder main control chip, the output end of the thirteenth operational amplifier is connected to the digital-to-analog conversion connection port, and the digital-to-analog conversion connection port is connected to the driving circuit.

Optionally, the high-voltage board circuit includes a high-voltage board circuit connection port, a high-speed pulse circuit, and a ninth transformer, the high-voltage board circuit connection port is connected to the high-frequency circuit and the high-speed pulse circuit, the high-speed pulse circuit is connected to a primary winding of the ninth transformer, and a secondary winding of the ninth transformer is connected to the welder input circuit and the sampling output circuit.

Optionally, the input circuit of the welding machine comprises a capacitor plate circuit, a variable frequency rectification circuit and a fourth transformer; the input end of the capacitor plate circuit is connected with a mains supply, the output end of the capacitor plate circuit is connected with the primary winding of the fourth transformer and the variable-frequency rectification circuit, the secondary winding of the fourth transformer is connected with the driving circuit, and the variable-frequency rectification circuit is connected with the sampling output circuit.

Optionally, the sampling output circuit includes a current sampling circuit, a voltage sampling circuit, a power supply positive output end and a power supply negative output end, the current sampling circuit is connected with the frequency conversion rectification circuit and the power supply positive output end, the voltage sampling circuit is connected with the power supply positive output end and the power supply negative output end, and the power supply positive output end and the power supply negative output end are connected with the feedback circuit.

Optionally, the driving circuit includes a driving main control chip, a driving power supply circuit, a signal receiving circuit, a protection circuit, a current transformer, and a driving signal output circuit; the driving main control chip is connected with the driving power supply circuit, the signal receiving circuit, the protection circuit and the driving signal output circuit, the driving power supply circuit is connected with a secondary winding of the fourth transformer, the signal receiving circuit, the protection circuit and the driving signal output circuit, the signal receiving circuit is connected with the digital-to-analog conversion connection port, the protection circuit is connected with the current transformer, the current transformer is connected with the frequency conversion rectification circuit, and the driving signal output circuit is also connected with the frequency conversion rectification circuit.

The embodiment of the utility model provides an above-mentioned one or more technical scheme in the digital welding machine control circuit with feedback and protect function have one of following technological effect at least:

the utility model discloses a set up welding machine input circuit sampling output circuit output control circuit with drive circuit, when using welding machine input circuit converts the alternating current of input into the direct current to for the welding machine provides the direct current, pass through simultaneously sampling output circuit will the current-voltage of frequency conversion welding machine input circuit output samples, output control circuit receives and comes from behind sampling output circuit's the sampling signal, through drive circuit control welding machine input circuit is with the adjustment the voltage of welding machine input circuit output, and then realize the feedback and the regulatory function of control circuit in the use of electric welding, guarantee the stability of the whole circuit of the control circuit of electric welding, promoted the welding efficiency of electric welding, had high practicality.

The invention also provides a digital welding machine which comprises the digital welding machine control circuit with the feedback and protection functions.

The embodiment of the utility model provides an above-mentioned one or more technical scheme in the digital welding machine have one of following technological effect at least:

because the digital welding machine comprises the digital welding machine control circuit with the feedback and protection functions, the digital welding machine can also realize the feedback and regulation functions of the welding machine in the use process, the stability of the whole circuit of the control circuit of the welding machine is ensured, and the digital welding machine has the advantage of improving the spot welding efficiency.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments or the prior art descriptions will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive labor.

Fig. 1 is a schematic circuit diagram of a digital welding machine control circuit and a digital welding machine with feedback and protection functions provided by an embodiment of the present invention;

fig. 2 is a circuit block diagram of a digital welding machine control circuit and a digital welding machine with feedback and protection functions provided by the embodiment of the present invention;

fig. 3 is a schematic circuit diagram of a driving circuit according to an embodiment of the present invention;

fig. 4 is a schematic circuit diagram of a digital signal processing circuit according to an embodiment of the present invention;

fig. 5 is a schematic circuit diagram of a high-voltage board circuit according to an embodiment of the present invention.

The various reference numbers in the figures:

welder input circuit-100 capacitance plate circuit-110 EMC filter circuit-111

Rectifying and filtering circuit-112 frequency conversion rectifying circuit-120 IGBT full bridge inverter circuit-121

Full-wave rectifying circuit-122 sampling output circuit-200 current sampling circuit-210

Voltage sampling circuit 220 driving circuit 300 driving power supply circuit 310

Signal receiving circuit-320 protection circuit-330 driving signal output circuit-340

Output control circuit-400 digital signal processing circuit-401 high-voltage board circuit-402

MCU power supply circuit-410 MCU main power supply circuit-411 MCU voltage stabilizing circuit-412

Feedback circuit-413 MCU drive circuit-420 high frequency circuit-430

Welder functional circuit-440 display circuit-441 encoder circuit-442

Welding gun switch circuit-443 temperature controller circuit-444 gas valve circuit-445

A light emitting circuit, a 446 welding gun voltage stabilizing circuit, a 447 high-speed pulse circuit, 450.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below by referring to the drawings are exemplary and intended to explain the embodiments of the present invention and are not to be construed as limiting the present invention.

In the description of the embodiments of the present invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings, which is only for convenience in describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element so indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating 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 the embodiments of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the embodiments of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly, e.g., as fixed or detachable connections or as an integral part; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the embodiments of the present invention can be understood by those skilled in the art according to specific situations.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

As shown in FIG. 1 and FIG. 2, a digital welder control circuit with feedback and protection functions is provided, which comprises a welder input circuit 100, a sampling output circuit 200, a driving circuit 300 and an output control circuit 400.

The input circuit 100 of the welding machine is connected to the mains supply and converts the ac power input by the mains supply into dc power. The sampling output circuit 200 is coupled to the welder input circuit 100 and is configured to sample a voltage provided by the welder input circuit 100. The output control circuit 400 is connected to the sampling output circuit 200 and is used to obtain the voltage sampled by the sampling output circuit 200. The driver circuit 300 is connected to the output control circuit 400 and the welder input circuit 100.

The utility model discloses a set up welding machine input circuit 100 sampling output circuit 200 output control circuit 400 with drive circuit 300, when using welding machine input circuit 100 converts the alternating current of input into the direct current to for the welding machine provides the direct current, pass through simultaneously sampling output circuit 200 will the current-voltage of welding machine input circuit 100 output samples, output control circuit 400 receives and comes from behind sampling output circuit 200's the sampling signal, through drive circuit 300 control welding machine input circuit 100 is with the adjustment the voltage of welding machine input circuit 100 output, and then realize the feedback and the regulatory function of the control circuit of electric welding in the use, guarantee the stability of the control circuit's of electric welding overall circuit, promoted spot welding efficiency, have high practicality.

Specifically, the output control circuit 400 includes a digital signal processing circuit 401 and a high voltage board circuit 402. The high-voltage board circuit 402 is connected with the welder input circuit 100 and the sampling output circuit 200, and the digital signal processing circuit 401 is connected with the high-voltage board circuit 402, the sampling output circuit 200 and the driving circuit 300.

In another embodiment of the present invention, as shown in fig. 1, fig. 2 and fig. 4, the digital signal processing circuit 401 includes a welder main control chip U1, an MCU power circuit 410, an MCU driving circuit 420, a high frequency circuit 430 and a welder function circuit 440. The welding machine main control chip U1 is respectively connected with the MCU power circuit 410, the MCU drive circuit 420, the high-frequency circuit 430 and the welding machine function circuit 440, the MCU power circuit 410 is connected with the welding machine input circuit 100, the MCU drive circuit 420 is connected with the drive circuit 300, and the high-frequency circuit 430 is connected with the high-voltage board circuit 402.

Specifically, the welder main control chip U1 comprises a serial port CN4 and a hardware port CN 5. The fifth pin of the serial port CN4 is connected with the twenty-ninth pin of the welder main control chip U1, the fourth pin of the serial port CN4 is connected with the thirty-second pin of the welder main control chip U1, the third pin of the serial port CN4 is connected with the thirty-third pin of the welder main control chip U1, the second pin of the serial port CN4 is connected with the thirty-fourth pin of the welder main control chip U1, the second pin of the hardware port CN5 is connected with the thirty-fifth pin of the welder main control chip U1, and the third pin of the hardware port CN5 is connected with the thirty-sixth pin of the welder main control chip U1.

Further, the welder main control chip U1 is preferably STM32G071C8T6-LQFP 48.

Specifically, the MCU power circuit 410 includes an MCU main power circuit 411, an MCU voltage stabilizing circuit 412 and a feedback circuit 413. The MCU main power circuit 411, the MCU voltage stabilizing circuit 412 and the feedback circuit 413 are all connected with the welder main control chip U1, the MCU main power circuit 411 is connected with the welder input circuit 100, the MCU voltage stabilizing circuit 412 is connected with the MCU main power circuit 411, and the feedback circuit 413 is connected with the sampling output circuit 200.

Specifically, the MCU main power circuit 411 includes an MCU power circuit connection port CN1, a third rectifier bridge B3, a fourth rectifier bridge B4, a first voltage-regulator power chip U14, and a second voltage-regulator power chip U15. The MCU power supply circuit connecting port CN1 is connected with the welding machine input circuit 100, the third rectifier bridge B3 is connected with the first pin and the second pin of the MCU power supply circuit connecting port CN1, the fourth rectifier bridge B4 is connected with the fourth pin and the fifth pin of the MCU power supply circuit connecting port CN1, the third rectifier bridge B3 is connected with the input end of the first voltage-stabilizing power supply chip U14, the output end of the fourth rectifier bridge B4 is connected with the input end of the second voltage-stabilizing power supply chip U15, the first voltage-stabilizing power supply chip U14 outputs 5V voltage, and the second voltage-stabilizing power supply chip U15 outputs 24V voltage.

Further, the third rectifier bridge B3 in the MCU main power supply circuit 411 is preferably DB207S, the fourth rectifier bridge B4 in the MCU main power supply circuit 411 is preferably DB407S, the first voltage-regulator power supply chip U14 in the MCU main power supply circuit 411 is preferably LM2596S-5.0, and the second voltage-regulator power supply chip U15 in the MCU main power supply circuit 411 is preferably LM2596 HVS-ADJ.

Specifically, the MCU voltage stabilizing circuit 412 includes a first power module T6, a second power module T7, and a third voltage-stabilizing power chip U6. The first power supply module T6 and the second power supply module T7 are connected with 5V voltage, the output end of the first power supply module T6 is connected with the third voltage-stabilizing power supply chip U6, the third voltage-stabilizing power supply chip U6 outputs 3.3V voltage, and the second power supply module T7 outputs 12V voltage.

Further, the first power module T6 in the MCU voltage stabilizing circuit 412 is preferably B0505S-1W, the second power module T7 in the MCU voltage stabilizing circuit 412 is preferably a0512S-2W, and the third voltage-stabilized power chip U6 in the MCU voltage stabilizing circuit 412 is preferably AMS 1117-3.3.

Specifically, the feedback circuit 413 includes an analog-to-digital conversion port CN8, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a third capacitor C3, a fourth capacitor C4, a first transient suppression diode ZD2, a second transient suppression diode ZD4, a third transient suppression diode ZD5, and a fourth transient suppression diode ZD 6.

Further, the analog-to-digital conversion port CN8 is connected to the sampling circuit 200, one end of the fifth resistor R5, the sixth resistor R6, the third capacitor C3 and the fourth capacitor C4 is connected to the first pin of the analog-to-digital conversion port CN8, and the other end of the fifth resistor R5, the sixth resistor R6, the third capacitor C3 and the fourth capacitor C4 is connected to the second pin of the analog-to-digital conversion port CN 8.

The first pin of the analog-to-digital conversion port CN8 is further connected to the positive electrodes of the first transient suppression diode ZD2, the second transient suppression diode ZD4, the third transient suppression diode ZD5 and the fourth transient suppression diode ZD6, and the first pin of the analog-to-digital conversion port CN8 is grounded.

A second pin of the analog-to-digital conversion port CN8 is connected to cathodes of the first transient suppression diode ZD2 and the second transient suppression diode ZD4, a second pin of the analog-to-digital conversion port CN8 is connected to one end of the fourth resistor R4, the other end of the R4 is connected to an eleventh pin of the main control chip U1 of the welder, a cathode of the third transient suppression diode ZD5 is connected to a third pin of the analog-to-digital conversion port CN8, a third pin of the analog-to-digital conversion port CN8 is connected to a twelfth pin of the main control chip U1 of the welder, and a cathode of the fourth transient suppression diode ZD6 is connected to a fourth pin of the analog-to-digital conversion port CN 8.

In another embodiment of the present invention, the MCU driving circuit 420 comprises a thirteenth operational amplifier U13 and a digital-to-analog conversion connection port CN 3. The input end of the thirteenth operational amplifier U13 is connected to the welder main control chip U1, the output end of the thirteenth operational amplifier U13 is connected to the digital-to-analog conversion connection port CN3, and the digital-to-analog conversion connection port CN3 is connected to the driving circuit 300.

Specifically, an input end of the thirteenth operational amplifier U13 is connected to a fifteenth pin of the welder main control chip U1, an output end of the thirteenth operational amplifier U13 is connected to the first pin of the digital-to-analog conversion connection port CN3, and a second pin of the digital-to-analog conversion connection port CN3 is grounded.

Further, the thirteenth operational amplifier U6 is preferably LMV 358.

In another embodiment of the present invention, the high frequency circuit 430 includes a tenth photocoupler U10 and a high frequency circuit connection port CN 6. The MCU voltage stabilizing circuit 412 is connected with a tenth photoelectric coupler U10, the high-frequency circuit connecting port CN6 is connected with the output end of the tenth photoelectric coupler U10, and the input end of the tenth photoelectric coupler U10 is connected with the welder main control chip U1.

Specifically, an input end of the tenth photocoupler U10 is connected with the twenty-second pin of the welder main control chip U13. The high frequency circuit connection port CN6 is connected to the high voltage board circuit 402, the high frequency circuit connection port CN6 has 4 pins, and the third pin and the fourth pin of the high frequency circuit connection port CN6 are connected to the output terminal of the tenth photocoupler U10.

Further, the model of the tenth photocoupler U10 is preferably TLP 181.

In another embodiment of the present invention, as shown in fig. 1, fig. 2, fig. 4 and fig. 5, the high-voltage board circuit 402 includes a high-voltage board circuit connection port CN13, a high-speed pulse circuit 450 and a ninth transformer T9. The high-voltage board circuit connection port CN13 is connected to the high-frequency circuit 430 and the high-speed pulse circuit 450, the high-speed pulse circuit 450 is connected to the primary winding of the ninth transformer T9, and the secondary winding of the ninth transformer T9 is connected to the welder input circuit 100 and the sampling output circuit 200.

Specifically, the high-voltage board circuit connection port CN13 is connected to the high-frequency circuit connection port CN6, the first pin of the high-voltage board circuit connection port CN13 is connected to the first pin of the high-frequency circuit connection port CN6, the second pin of the high-voltage board circuit connection port CN13 is connected to the second pin of the high-frequency circuit connection port CN6, the third pin of the high-voltage board circuit connection port CN13 is connected to the third pin of the high-frequency circuit connection port CN6, and the fourth pin of the high-voltage board circuit connection port CN13 is connected to the fourth pin of the high-frequency circuit connection port CN 6.

Specifically, the high-speed pulse circuit 450 includes a thirteenth diode Q10, an eleventh transistor Q11, and a twelfth MOS transistor Q12. Bases of the thirteenth electrode tube Q10 and the eleventh electrode tube Q11 are connected to the second pin of the high-voltage plate circuit connection port CN13, an emitter of the eleventh electrode tube is connected with an emitter of the thirteenth electrode tube, a collector of the thirteenth electrode tube is connected with the third pin of the high-voltage plate circuit connection port CN13, and an emitter of the thirteenth electrode tube is connected with a gate of the twelfth MOS tube Q12. A first pin of the high-voltage board circuit connection port CN13, a collector of the eleventh triode, and a source of a twelfth MOS transistor Q12 are all grounded, a fourth pin of the high-voltage board circuit connection port CN13 is connected with a drain of the twelfth MOS transistor Q12, the drain of the twelfth MOS transistor Q12 is further connected with a primary winding of the ninth transformer T9, and a secondary winding of the ninth transformer T9 outputs a high-voltage signal to a negative output terminal of a power supply through a connection terminal.

The second pin of the high-voltage board circuit connection port CN13 controls a PWM high-speed pulse signal, the PWM high-speed pulse signal controls the conduction of a thirteenth triode Q10 and an eleventh triode Q11, so that the twelfth MOS tube Q12 is driven to be conducted, the ninth transformer T9 is a step-up transformer, after the twelfth MOS tube Q12 is repeatedly conducted and disconnected, a +75V direct-current signal is changed into a high-frequency pulse alternating-current signal, the high-frequency pulse alternating-current signal is boosted through the ninth transformer T9, the +75V high-frequency pulse alternating-current signal is boosted to a high-voltage signal of thousands of volts and then is connected to an arc striking coil, and finally the high-frequency pulse alternating-current signal is coupled to a workpiece to break down air, so that the arc striking process is completed.

In another embodiment of the present invention, as shown in fig. 1 to 2, the input circuit 100 of the welding machine includes a capacitor plate circuit 110, a variable frequency rectifier circuit 120 and a fourth transformer T4; the input end of the capacitor plate circuit 110 is connected with a mains supply, the output end of the capacitor plate circuit 110 is connected with the primary winding of the fourth transformer T4 and the variable frequency rectification circuit 120, the secondary winding of the fourth transformer T4 is connected with the driving circuit 300, and the variable frequency rectification circuit 120 is connected with the sampling output circuit 200.

The capacitor board circuit 110 includes an EMC filter circuit 111 and a rectifying filter circuit 112. The input end of the EMC filter circuit 111 is connected to the mains supply, the output end of the EMC filter circuit 111 is connected to the rectifier filter circuit 112, the rectifier filter circuit 112 is connected to the primary winding of the fourth transformer T4 and the variable frequency rectifier circuit 120, and the secondary winding of the fourth transformer T4 is connected to the driving circuit 300.

Specifically, the EMC filter circuit 111 includes a first common-mode rejection capacitor Y1, a second common-mode rejection capacitor Y2, and a first common-mode rejection inductor T1. The positive input end of the power supply, the negative input end of the power supply and a first common-mode rejection capacitor Y1 are connected with a first pin and a third pin of the first common-mode rejection inductor T1, a second pin and a fourth pin of the first common-mode rejection inductor T1 are connected with a second common-mode rejection capacitor Y2, and the second common-mode rejection capacitor Y2 is connected with a first pin and a second pin of the fourth transformer T4.

Specifically, as shown in fig. 1, the rectifying and smoothing circuit 112 includes a first rectifying bridge B1, a first capacitor C1, a second capacitor C2, and a first resistor R1. The input end of the first rectifier bridge B1 is connected to the second common mode rejection capacitor Y2, the output end of the first rectifier bridge B1 is connected to the first capacitor C1, the second capacitor C2 and the first resistor R1, the first capacitor C1 is connected to the second capacitor C2, the second capacitor C2 is connected to the first resistor R1, and the first resistor R1 is connected to the full bridge inverter circuit 121. And outputting relatively stable 380V direct-current voltage to provide power input for the welding machine, wherein the first resistor R1 slowly discharges the voltage at two ends of the first capacitor and the second capacitor to 0V after shutdown.

Specifically, as shown in fig. 1, fig. 2 and fig. 4, a sixth pin of the secondary winding of the fourth transformer T4 is connected to the first pin of the MCU power circuit connection port CN1, a seventh pin of the secondary winding of the fourth transformer T4 is connected to the second and third pins of the MCU power circuit connection port CN1, and an eighth pin of the secondary winding of the fourth transformer T4 is connected to the fourth pin of the MCU power circuit connection port CN 1.

The variable frequency rectification circuit 120 comprises an IGBT full bridge inverter circuit 121 and a full wave rectification circuit 122. The IGBT full-bridge inverter circuit 121 is connected to the driving circuit 300 and the full-wave rectifier circuit 122, the IGBT full-bridge inverter circuit 121 is further connected to the rectifier filter circuit 112, and the full-wave rectifier circuit 122 is connected to the sampling output circuit 200.

Specifically, as shown in fig. 1 to 4, the IGBT full-bridge inverter circuit 121 includes a first insulated gate bipolar transistor Q1, a second insulated gate bipolar transistor Q2, a third insulated gate bipolar transistor Q3, and a fourth insulated gate bipolar transistor Q4. The collector of the first insulated gate bipolar transistor Q1 is connected with one end of the first resistor R1, the collector of the third insulated gate bipolar transistor Q3 is connected with the collector of the first insulated gate bipolar transistor Q1, the emitter of the first insulated gate bipolar transistor Q1 is connected with the collector of the second insulated gate bipolar transistor Q2, the emitter of the third insulated gate bipolar transistor Q3 is connected with the collector of the fourth insulated gate bipolar transistor Q4, the emitter of the second insulated gate bipolar transistor Q2 is connected with the other end of the first resistor R1, and the emitter of the fourth insulated gate bipolar transistor Q4 is connected with the emitter of the second insulated gate bipolar transistor Q2. The gates of the first insulated gate bipolar transistor Q1, the second insulated gate bipolar transistor Q2, the third insulated gate bipolar transistor Q3 and the fourth insulated gate bipolar transistor Q4 are connected with the driving circuit 300.

The first insulated gate bipolar transistor Q1 and the fourth insulated gate bipolar transistor Q4 are identical in driving phase, the second insulated gate bipolar transistor Q2 and the third insulated gate bipolar transistor Q3 are identical in driving phase, the first insulated gate bipolar transistor Q1 and the fourth insulated gate bipolar transistor Q4, the second insulated gate bipolar transistor Q2 and the third insulated gate bipolar transistor Q3 are alternately conducted in turn, and direct-current signals are converted into high-frequency alternating-current signals.

Specifically, the full-wave rectification circuit 122 includes a second transformer T2, a first inductor L1, a second inductor L2, a first diode D1, and a second diode D2. A first pin of the primary winding of the second transformer T2 is connected to the emitter of the third igbt Q3, a second pin of the primary winding of the second transformer T2 is connected to the emitter of the first igbt Q1, and a second pin of the primary winding of the second transformer T2 is further connected to the driving circuit 300. The fifth pin of the secondary winding of the second transformer T2 is grounded, the third pin of the secondary winding of the second transformer T2 is connected to the anode of the first diode D1, the fourth pin of the secondary winding of the second transformer T2 is connected to the anode of the second diode, the cathode of the second diode is connected to the cathode of the first diode, and the cathode of the first diode D1 is connected to the sampling output circuit 200. One end of the first inductor L1 is connected to the fifth pin of the secondary winding of the second transformer, the other end of the first inductor L1 is connected to one end of the second inductor L2, and the other end of the second inductor L2 is connected to the sampling output circuit 200. The full-wave rectifying circuit 122 rectifies the ac signal into a dc signal, and outputs the dc signal to the sampling output circuit 200.

In another embodiment of the present invention, as shown in fig. 1, fig. 2 and fig. 4, the sampling output circuit 200 includes a current sampling circuit 210, a voltage sampling circuit 220, a power positive output terminal and a power negative output terminal, the current sampling circuit 210 is connected to the full-wave rectification circuit 122 and the power positive output terminal, the voltage sampling circuit 220 is connected to the power positive output terminal and the power negative output terminal, the current sampling circuit 210 is connected to the voltage sampling circuit 220, and the feedback circuit 413 is connected to the voltage sampling circuit 220.

Specifically, the current sampling circuit 210 includes a current hall sensor H1. The input end of the current Hall sensor H1 is connected with the cathodes of the first diode D1 and the second diode D2, and the current Hall sensor H1 is connected with the positive output end of the power supply and the third pin and the fourth pin of the analog-to-digital conversion port CN 8. When a load is connected to the power output end, the current hall sensor H1 outputs a corresponding voltage signal to the analog-to-digital conversion port CN8 for current sampling according to the magnitude of the output current, converts the analog signal into a digital signal, compares the sampled current data with the current value set by the operation panel, obtains a corresponding control value after PID high-speed operation by the digital signal processing circuit 401, converts the digital signal into the analog signal by the digital signal processing circuit 401, and outputs the analog signal to the driving circuit 300 through the digital-to-analog conversion connection port CN3 for real-time update of the PWM duty ratio, so that the actually output current is always consistent with the value set by the panel.

Specifically, the voltage sampling circuit 220 includes a second resistor R2 and a third resistor R3. One end of the second resistor R2 is connected with the positive output end of the power supply and is connected with one end of the third resistor R3, and the other end of the third resistor R3 is connected with the negative output end of the power supply. The voltage sampling circuit 220 is connected to the analog-to-digital conversion port CN8, one end of the second resistor R2, which is connected to the third resistor R3, is connected to the first pin of the analog-to-digital conversion port CN8, and the negative output end of the power supply is connected to the second pin of the analog-to-digital conversion port CN 8. The output arc voltage is divided by the second resistor R2 and the third resistor R3 to obtain a lower voltage signal, the lower voltage signal is sent to the analog-to-digital conversion port CN8 for voltage sampling, and when the output arc voltage is higher or lower than a set threshold value, the current is finely adjusted in proportion according to the magnitude of the arc voltage, so that a better welding effect is achieved.

In another embodiment of the present invention, as shown in fig. 1 to 4, the driving circuit 300 includes a driving main control chip U2, a driving power supply circuit 310, a signal receiving circuit 320, a protection circuit 330, a current transformer T3, and a driving signal output circuit 340. The drive main control chip U2 with drive power supply circuit 310, signal receiving circuit 320, protection circuit 330 and drive signal output circuit 340 all connect, drive power supply circuit 310 with the secondary winding of fourth transformer T4 the signal receiving circuit 320 protection circuit 330 with drive signal output circuit 340 connects, signal receiving circuit 320 with digital-to-analog conversion connection port CN3 connects, protection circuit 330 with current transformer T3 connects, current transformer T3 with the second pin of second transformer T2 primary winding connects, drive signal output circuit 340 with IGBT full-bridge inverter circuit 121 connects.

Further, the model of the main control chip U2 is preferably UC 3846.

Specifically, the driving power supply circuit 310 includes a driving power supply circuit connection port CN10, a second rectifier bridge B2, a three-terminal positive regulator U3, and a three-terminal negative regulator U4. The driving power supply circuit connection port CN10 is connected to the secondary winding of the fourth transformer T4, the first pin of the driving power supply circuit connection port CN10 is connected to the third pin of the secondary winding of the fourth transformer T4, the second pin of the driving power supply circuit connection port CN10 is connected to the fourth pin of the secondary winding of the fourth transformer T4, and the third pin of the driving power supply circuit connection port CN10 is connected to the fifth pin of the secondary winding of the fourth transformer T4. The input end of the second rectifier bridge B2 is connected to the first and third pins of the driving power supply circuit connection port CN10, and the second pin of the driving power supply circuit connection port CN10 is grounded. The positive pole of the second rectifier bridge B2 is connected with the input end of the three-terminal positive voltage stabilizer U3, the negative pole of the second rectifier bridge B2 is connected with the input end of the three-terminal negative voltage stabilizer U4, the three-terminal positive voltage stabilizer U3 is grounded with one end of the three-terminal negative voltage stabilizer U4, the output end of the three-terminal positive voltage stabilizer U3 outputs +15V voltage, the output end of the three-terminal negative voltage stabilizer U4 outputs-15V voltage, and the output end of the three-terminal positive voltage stabilizer U3 is connected with the fifteenth pin of the driving main control chip U2.

Further, the model of the three-terminal positive regulator U3 is preferably LM7815, and the model of the three-terminal negative regulator U4 is preferably LM 7915.

Specifically, the signal receiving circuit 320 includes a signal receiving circuit connection port CN11 and a fifth operational amplifier U5. The signal receiving circuit connection port CN11 is connected to the MCU drive circuit connection port CN3, a first pin of the signal receiving circuit connection port CN11 is connected to a second pin of the MCU drive circuit connection port CN3, and a second pin of the signal receiving circuit connection port CN11 is connected to a first pin of the MCU drive circuit connection port CN 3. The second pin of the signal receiving circuit connection port CN11 is grounded, the non-inverting input terminal of the fifth operational amplifier U5 is connected to the first pin of the signal receiving port CN11, and the non-inverting output terminal of the fifth operational amplifier U5 is connected to the fifth pin of the driving main control chip U2.

Specifically, the protection circuit 330 includes a protection circuit connection port CN12 and a sixteenth operational amplifier U16. The protection circuit connection port CN12 is connected to the current transformer T3, the output end of the sixteenth operational amplifier U16 is connected to the protection circuit connection port CN12, the input end of the sixteenth operational amplifier U16 is connected to the eighth pin of the driving main control chip U2, and the protection circuit connection port CN12 is further connected to the fourth pin of the driving main control chip U2.

Specifically, the driving signal output circuit 340 includes a fifth MOS transistor Q5, a sixth MOS transistor Q6, a seventh MOS transistor Q7, an eighth MOS transistor Q8, a fifth transformer T5, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, and a fourteenth resistor R14.

Specifically, the gate of the fifth MOS transistor Q5 and the gate of the seventh MOS transistor Q7 are connected to the fourteenth pin of the driving main control chip U2, the drain of the fifth MOS transistor Q5 is connected to the drain of the seventh MOS transistor Q7 and the ninth pin of the primary winding of the fifth transformer T5, the source of the fifth MOS transistor Q5 is connected to the source of the sixth MOS transistor Q6, the gate of the sixth MOS transistor Q6 and the gate of the eighth MOS transistor Q8 are connected to the eleventh pin of the driving main control chip U2, the drain of the sixth MOS transistor Q6 is connected to the drain of the eighth MOS transistor Q8 and the tenth pin of the primary winding of the fifth transformer T5, and the sources of the seventh MOS transistor Q7 and the eighth MOS transistor Q8 are grounded.

Specifically, one end of the seventh resistor R7 is connected to the second pin of the fifth transformer T5, the other end of the seventh resistor R7 is connected to the gate of the first igbt Q1, one end of the eighth resistor R8 is connected to the third pin of the fifth transformer T5, the other end of the eighth resistor R8 is connected to the gate of the second igbt Q2, one end of the ninth resistor R9 is connected to the sixth pin of the fifth transformer T5, the other end of the ninth resistor R9 is connected to the gate of the third igbt Q3, one end of the tenth resistor R10 is connected to the seventh pin of the fifth transformer T5, and the other end of the tenth resistor R10 is connected to the gate of the fourth igbt Q4. The seventh resistor R7, the eighth resistor R8, the ninth resistor R9 and the tenth resistor R10 are driving resistors and provide driving signals for the insulated gate bipolar transistor.

Specifically, the third diode D3 and the eleventh resistor R11 are connected and connected in reverse parallel at two ends of the seventh resistor R7, the fourth diode D4 and the twelfth resistor R12 are connected and connected in reverse parallel at two ends of the eighth resistor R8, the fifth diode D5 and the thirteenth resistor R13 are connected and connected in reverse parallel at two ends of the ninth resistor R9, the sixth diode D6 and the fourteenth resistor R14 are connected and connected in reverse parallel at two ends of the tenth resistor R10, so as to form an accelerated turn-off signal of the insulated gate bipolar transistor, thereby effectively reducing turn-off loss of the insulated gate bipolar transistor and reducing heat generation of the insulated gate bipolar transistor.

In another embodiment of the present invention, as shown in fig. 4, the welder function circuit 440 includes a display circuit 441, an encoder circuit 442, a welding gun switch circuit 443, a temperature controller circuit 444 and a gas valve circuit 445, the MCU main power circuit 411 is respectively connected to the display circuit 441, the encoder circuit 442, the welding gun switch circuit 443, the temperature controller circuit 444 and the gas valve circuit 445, and the MCU voltage stabilizing circuit 412 is respectively connected to the encoder circuit 442, the welding gun switch circuit 443, the temperature controller circuit 444 and the gas valve circuit 445; the welder main control chip U1 is connected with the display circuit 441, the encoder circuit 442, the welding gun switch circuit 443, the temperature controller circuit 444 and the gas valve circuit 445.

In another embodiment of the present invention, the display circuit 441 includes a nixie tube driver chip U7 and a light emitting circuit 446, the nixie tube driver chip U7 is connected to the MCU main power circuit 411 and the welder main control chip U1, and the light emitting circuit 446 is connected to the nixie tube driver chip U7.

Further, the nixie tube driving chip U7 is preferably TM 1639.

Specifically, the light emitting circuit 446 includes a three-position nixie tube U8, the three-position nixie tube U8 is connected to a first pin, a second pin, a fourth pin, a fifth pin, a twelfth pin, a thirteenth pin, a fourteenth pin, a fifteenth pin, a sixteenth pin, a seventeenth pin, an eighteenth pin and a nineteenth pin of the nixie tube driving chip U7, a sixth pin of the nixie tube driving chip U7 is connected to a twenty-seventh pin of the welder driving chip U1, a seventh pin of the nixie tube driving chip U7 is connected to a twenty-eighth pin of the welder driving chip U1, an eighth pin of the nixie tube driving chip U7 is connected to a thirty-eighth pin of the welder driving chip U1, a sixth pin, a seventh pin, an eighth pin and an eleventh pin of the nixie tube driving chip U7 are connected to a 5V power supply, a ninth pin of the nixie tube driving chip U7 is connected to a second switch SW2, a tenth pin of the nixie tube driving chip U7 is connected to the first switch SW1 and the third switch SW2, the other ends of the first switch SW1 and the second switch SW2 are connected to a twelfth pin of the nixie tube driving chip U7, and the other end of the third switch SW3 is connected to a thirteenth pin of the nixie tube driving chip U7.

In another embodiment of the present invention, the encoder circuit 442 includes an encoder P1 and a buzzer BP 1. The encoder P1 is connected with the welder main control chip U1 and the MCU voltage stabilizing circuit 412, and the buzzer BP1 is connected with the welder main control chip U1 and the MCU main power circuit 411.

Specifically, the first pin of the encoder P1 is connected with the nineteenth pin of the welder main control chip U1, the third pin of the encoder P1 is connected with the twentieth pin of the welder main control chip U1, the fifth pin of the encoder P1 is connected with the twenty-first pin of the welder main control chip U1, and the second pin and the fourth pin of the P1 of the encoder are grounded. The input end of the buzzer BP1 is connected with a first pin of the welding machine main control chip U1, and the second pin of the buzzer BP1 is used for inputting a 5V power supply.

Further, the type of the encoder P1 is preferably EC 11.

In another embodiment of the present invention, the welding gun switch circuit 443 includes a welding gun switch SW4, a welding gun switch circuit connection port CN7, a twelfth photocoupler U12 and a welding gun voltage stabilizing circuit 447. The welding gun switch SW4 is connected with a first pin and a third pin of the welding gun switch connecting port CN7, the welding gun switch circuit connecting port CN7 is connected with the welding gun voltage stabilizing circuit 447, and the welding gun voltage stabilizing circuit 447 is connected with the twelfth photoelectric coupler U12.

Specifically, the welding gun voltage stabilizing circuit 447 includes an eighth transformer T8, a first pin of the eighth transformer T8 is connected to a first pin of the welding gun connection port CN7, a third pin of the eighth transformer T8 is connected to a third pin of the welding gun connection port CN7, a second pin of the eighth transformer T8 is connected to an input terminal of a twelfth photocoupler U12, a fourth pin of the eighth transformer T8 is grounded, an input terminal of the twelfth photocoupler U12 is connected to the eighth transformer T8, and an output terminal of the twelfth photocoupler U12 is connected to a twenty-sixth pin of the welding machine main control chip U1.

Further, the model of the twelfth photocoupler U12 is preferably TLP 181.

In another embodiment of the present invention, the thermostat circuit 444 includes a ninth photocoupler U9 and a thermostat connection port CN 2. The MCU voltage stabilizing circuit 412 is connected with a ninth photoelectric coupler U9, the temperature controller connecting port CN2 is connected with the input end of the ninth photoelectric coupler U9, and the output end of the ninth photoelectric coupler U9 is connected with the welding machine main control chip U1.

Specifically, a first pin of the temperature controller connection port CN2 is connected to an input terminal of the ninth photoelectric coupler U9, a second pin of the temperature control circuit port CN2 is grounded, and an output terminal of the ninth photoelectric coupler U9 is connected to a twenty-fifth pin of the welder main control chip U13.

Further, the model of the ninth photocoupler U9 is preferably TLP 181.

In another embodiment of the present invention, the air valve circuit 445 includes an eleventh photocoupler U11 and an air valve connection port CN 9. The MCU voltage stabilizing circuit 412 is connected with an eleventh photoelectric coupler U11, the air valve connecting port CN9 is connected with the output end of the eleventh photoelectric coupler U11, and the input end of the eleventh photoelectric coupler U11 is connected with the welder main control chip U1.

Specifically, an input end of an eleventh photoelectric coupler U11 in the air valve circuit 445 is connected with a twenty-third pin of the welder main control chip U13. The air valve connecting port CN9 is provided with 3 pins, the first pin and the third pin of the air valve connecting port CN9 are connected with the output end of the eleventh photoelectric coupler U11, and the air valve connecting port CN9 is used for being connected with an air valve.

Further, the model of the eleventh photocoupler U11 is preferably TLP 181.

It should be noted that the distance between the chip types in the present application is only for illustrating the functions to be implemented by the circuits in the present application, and is not limited to a specific chip type. In practical use, a person skilled in the art can replace the chip according to actual needs as long as the functions required to be realized by each circuit of the present application can be achieved, and the present application is not particularly limited.

In addition, the present application focuses on protecting the circuit structure, and for the program control, a person skilled in the art should perform corresponding programming processing according to the chip model provided in the present application to implement the control function required by the present application, and therefore, the present application is not specifically described herein.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims (10)

1. A digital welder control circuit with feedback and protection functions comprises:

a welder input circuit (100), said welder input circuit (100) converting an input alternating current to a direct current, characterized by further comprising:

the sampling output circuit (200), the sampling output circuit (200) is connected with the welder input circuit (100) and samples the voltage output by the welder input circuit;

the output control circuit (400), the output control circuit (400) is connected with the sampling output circuit (200) and obtains the voltage sampled by the sampling output circuit (200);

a driver circuit (300), the driver circuit (300) being connected to the output control circuit (400) and the welder input circuit (100).

2. The digital welder control circuit with feedback and protection functions according to claim 1, characterized in that the output control circuit (400) comprises a digital signal processing circuit (401) and a high voltage board circuit (402);

the high-voltage board circuit (402) is connected with the welder input circuit (100) and the sampling output circuit (200), and the digital signal processing circuit (401) is connected with the high-voltage board circuit (402), the sampling output circuit (200) and the driving circuit (300).

3. The digital welder control circuit with feedback and protection functions of claim 2, characterized in that the digital signal processing circuit (401) comprises a welder main control chip (U1), an MCU power supply circuit (410), an MCU driver circuit (420), a high frequency circuit (430) and a welder function circuit (440); the welding machine main control chip (U1) with MCU power supply circuit (410), MCU drive circuit (420), high frequency circuit (430) and welding machine function circuit (440) all connect, MCU power supply circuit (410) with welding machine input circuit (100) is connected, MCU drive circuit (420) with drive circuit connects (300), high frequency circuit (430) with high-voltage board circuit (402) are connected.

4. The digital welder control circuit with feedback and protection functions according to claim 3, characterized in that the MCU power supply circuit (410) comprises an MCU main power supply circuit (411), an MCU voltage stabilizing circuit (412) and a feedback circuit (413); the MCU main power circuit (411), the MCU voltage stabilizing circuit (412) and the feedback circuit (413) are all connected with the welder main control chip (U1), the MCU main power circuit (411) is connected with the welder input circuit (100), the MCU voltage stabilizing circuit (412) is connected with the MCU main power circuit (411), and the feedback circuit (413) is connected with the sampling output circuit (200).

5. The digital welder control circuit with feedback and protection functions of claim 4, characterized in that the MCU driving circuit (420) comprises a thirteenth operational amplifier (U13) and a digital-to-analog conversion connection port (CN 3); the input end of the thirteenth operational amplifier (U13) is connected with the welder main control chip (U1), the output end of the thirteenth operational amplifier (U13) is connected with the digital-to-analog conversion connection port (CN3), and the digital-to-analog conversion connection port (CN3) is connected with the driving circuit (300).

6. The digital welder control circuit with feedback and protection functions of claim 5, characterized in that the high-voltage board circuit (402) comprises a high-voltage board circuit connection port (CN13), a high-speed pulse circuit (450) and a ninth transformer (T9); the high-voltage board circuit connection port (CN13) is connected with the high-frequency circuit (430) and the high-speed pulse circuit (450), the high-speed pulse circuit (450) is connected with a primary winding of the ninth transformer (T9), and a secondary winding of the ninth transformer (T9) is connected with the welder input circuit (100) and the sampling output circuit (200).

7. The digital welder control circuit with feedback and protection functions according to claim 5 or 6, characterized in that the welder input circuit (100) comprises a capacitive plate circuit (110), a variable frequency rectification circuit (120) and a fourth transformer (T4); the input end of the capacitor plate circuit (110) is connected with a mains supply, the output end of the capacitor plate circuit (110) is connected with the primary winding of the fourth transformer (T4) and the variable-frequency rectification circuit (120), the secondary winding of the fourth transformer (T4) is connected with the driving circuit (300), and the variable-frequency rectification circuit (120) is connected with the sampling output circuit (200).

8. The digital welder control circuit with feedback and protection functions according to claim 7, characterized in that the sampling output circuit (200) comprises a current sampling circuit (210), a voltage sampling circuit (220), a power positive output terminal and a power negative output terminal; the current sampling circuit (210) is connected with the variable-frequency rectifying circuit (120) and the power supply positive output end, the voltage sampling circuit (220) is connected with the power supply positive output end and the power supply negative output end, and the current sampling circuit (210) and the voltage sampling circuit (220) are connected with the feedback circuit (413).

9. The digital welder control circuit with feedback and protection functions of claim 8, characterized in that the driving circuit (300) comprises a driving main control chip (U2), a driving power supply circuit (310), a signal receiving circuit (320), a protection circuit (330), a current transformer (T3) and a driving signal output circuit (340); the driving main control chip (U2) is connected with the driving power supply circuit (310), the signal receiving circuit (320), the protection circuit (330) and the driving signal output circuit (340), the driving power supply circuit (310) is connected with a secondary winding of the fourth transformer (T4), the signal receiving circuit (320), the protection circuit (330) and the driving signal output circuit (340) are connected, the signal receiving circuit (320) is connected with the digital-to-analog conversion connection port (CN3), the protection circuit (330) is connected with the current transformer (T3), the current transformer (T3) is connected with the frequency conversion rectification circuit (120), and the driving signal output circuit (340) is also connected with the frequency conversion rectification circuit (120).

10. A digital welder, characterized in that it comprises a digital welder control circuit with feedback and protection functions as claimed in any one of claims 1-9.

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