CN106334857B - A kind of arc welding arc ignition circuit - Google Patents
A kind of arc welding arc ignition circuit Download PDFInfo
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- CN106334857B CN106334857B CN201611047781.5A CN201611047781A CN106334857B CN 106334857 B CN106334857 B CN 106334857B CN 201611047781 A CN201611047781 A CN 201611047781A CN 106334857 B CN106334857 B CN 106334857B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/06—Arrangements or circuits for starting the arc, e.g. by generating ignition voltage, or for stabilising the arc
- B23K9/067—Starting the arc
- B23K9/0672—Starting the arc without direct contact between electrodes
- B23K9/0673—Ionisation of the arc gap by means of a tension with a step front (pulses or high frequency tensions)
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- Generation Of Surge Voltage And Current (AREA)
Abstract
The present invention provides a kind of arc welding arc ignition circuits, and for generating high frequency voltage with the electric arc that ignites, the arc welding arc ignition circuit includes：High-voltage charge and discharge circuit, including charge and discharge capacitance；Inversion step-up circuit, to charge to charge and discharge capacitance；Amplitude discrimination circuit, to judge whether the charging voltage of charge and discharge capacitance reaches electric discharge normal voltage, and when charge and discharge capacitance reaches electric discharge normal voltage so that inversion step-up circuit is stopped；Trigger circuit is connected with the charge and discharge capacitance, causes charge and discharge capacitance discharges to form high-voltage pulse to form access in discharge regime and charge and discharge capacitance；Single chip circuit, including microcontroller, the microcontroller is connected with the inversion step-up circuit, trigger circuit, to be timed control to charging stage, discharge regime and holding stage, and controls charging stage, discharge regime and is kept for the stage constantly carry out cycle until striking is successful.
Description
Technical field
The invention belongs to a kind of arc welding arc ignition circuit, particularly a kind of arc welding striking that stable high voltage pulse is provided
Circuit.
Background technology
Gas tungsten arc welding and the weldering of part plasma generally use high-frequency arc strike mode, this striking mode
Consistency and stability are poor, and bigger to extraneous interference.Particularly, at present using the microcomputers such as microcontroller, DSP, ARM
The more and more of gas tungsten arc welding and plasma weldering are controlled, this kind of microcomputer control chip is very quick to High-frequency Interference
Sense, vulnerability to jamming are very poor.In addition, the tungsten electrode noble gas protecting that the automation equipments such as mating welding robot, special plane use at present
The quantity of weldering and plasma arc welding (PAW) also increases year by year, and these automation equipments also have centainly the vulnerability to jamming of High-frequency Interference
It is required that.
In order to solve the problems, such as High-frequency Interference, other than the measure that high frequency is filtered out except through increasing filtering link etc., most root
This solution is exactly to change striking mode, so as to thoroughly eliminate interference source.And high-voltage pulse thread-leading arc mode can solve well
Certainly interference problem.
But the design of high-voltage pulse thread-leading arcs many at present is influenced by outer work condition, device aging, electric power thus supplied etc.
It is larger, cause waveform inconsistent, so as to will appear the situation that arcing initiation success rate is unstable under same environment.Therefore, it is necessary to it designs
A kind of high-frequency arc strike that can solve brings the arc welding arc ignition circuit that arcing initiation success rate is improved while interference.
At present, generally use Alternating Current Power Supply in most of technologies obtains direct current, then profit after then recycling bridge rectifier
The trigger pulse of frequency is determined with timer generation to control power device be the rectangular wave of determining frequency by the DC inverter, is passed through
Several kilovolts of high-voltage electricity is obtained after step-up transformer and high-voltage rectifier, then electricity is triggered by high-voltage charge and discharge circuit and spark
Road, so as to reach striking purpose.
But above-mentioned this high-frequency arc ignition circuit, concussion frequency shake amplitude to be differed between 100KHz to 300KHz
Be attenuation, and be only capable of maintaining 2 to be influenced to 6ms, and by outer work condition every time, the amplitude shaken every time and it is lasting when
Between it is unequal, and then cannot be guaranteed concussion waveform consistency, so as to affect the stability of striking effect and consistency.And
And the higher-order of oscillation can all bring serious electromagnetic interference to other electrical equipments and welding machine controller.
Invention content
The present invention provides a kind of arc welding arc ignition circuit, and for generating high frequency voltage with the electric arc that ignites, the arc welding is drawn
The course of work of arc circuit includes charging stage, discharge regime and is kept for the stage；The arc welding arc ignition circuit includes：High pressure is filled
Discharge circuit, including charge and discharge capacitance, charge and discharge capacitance one end ground connection；Inversion step-up circuit, with the charge and discharge capacitance
It is connected, is charged so that low level direct current is converted to high level alternating current in the charging stage to charge and discharge capacitance；Mirror
Width circuit is connected with the high-voltage charge and discharge road, to judge whether the charging voltage of charge and discharge capacitance reaches electric discharge standard electric
Pressure；And be connected with the inversion step-up circuit, so that inversion boosting is electric when charge and discharge capacitance reaches electric discharge normal voltage
Road is stopped；Trigger circuit is connected with the charge and discharge capacitance, is made with forming access with charge and discharge capacitance in discharge regime
Charge and discharge capacitance is obtained to discharge to form high-voltage pulse；Single chip circuit, including microcontroller, the microcontroller and inversion boosting electricity
Road, trigger circuit are connected, and to be timed control to charging stage, discharge regime and holding stage, and control charging rank
Section, discharge regime and holding stage constantly carry out cycle until striking success.
As a further improvement on the present invention, the amplitude discrimination circuit includes the partial pressure being connected with charge and discharge capacitance electricity
Road, three-terminal voltage regulator and optocoupler；The input terminal of the three-terminal voltage regulator is connected with the bleeder circuit, ground terminal
Ground connection, output terminal are connected with the input cathode of the optocoupler；The input anode of the optocoupler is connected with the first external voltage,
And the input anode of the optocoupler is connected by first resistor with the input cathode of optocoupler, the output anode of the optocoupler with
Second external voltage is connected, and output cathode is connected with the inversion step-up circuit.
As a further improvement on the present invention, the inversion step-up circuit includes inverter circuit and inverse-excitation converting circuit, institute
It states inverter circuit and includes current mode controller, NMOS tube, source electrode ground connection, grid and the current-mode control of the NMOS tube
The output terminal of device processed is connected；The inverse-excitation converting circuit includes the first transformer, and the armature winding of first transformer connects
It is connected between third external voltage and the drain electrode of NMOS tube, and the anode of the armature winding of first transformer and described the
Three external voltages are connected.
As a further improvement on the present invention, the inverter circuit further includes the first filter circuit, first filtered electrical
Road includes the first capacitance, second resistance and the first diode；First capacitance is parallel with one another with second resistance and one end is connect
To the third external voltage, the other end is connected to the cathode of first diode, the anode of first diode and institute
The drain electrode for stating NMOS tube is connected.
As a further improvement on the present invention, the secondary windings of first transformer includes the first secondary windings, and
The inverse-excitation converting circuit further includes the second diode；The anode of the cathode of first secondary windings and second diode
It is connected, the cathode of second diode is connected with the earth-free one end of the charge and discharge capacitance with electric to the charge and discharge
Capacity charge.
As a further improvement on the present invention, the inversion step-up circuit further includes voltage source circuit, first transformation
The secondary windings of device includes second subprime winding, and the voltage source circuit further includes the second subprime winding, described second
The anode of grade winding is connected by the second capacitance with the amplitude discrimination circuit.
As a further improvement on the present invention, the amplitude discrimination circuit includes the partial pressure being connected with charge and discharge capacitance electricity
Road, three-terminal voltage regulator and optocoupler；The input terminal of the three-terminal voltage regulator is connected with the bleeder circuit, ground terminal
Ground connection, output terminal are connected with the input cathode of the optocoupler；The input anode of the optocoupler and second capacitance are far from the
One end of the anode of secondary stage winding is connected, and passes through first resistor and be connected with the input cathode of optocoupler, the optocoupler
Output anode is connected with the second external voltage, and output cathode is connected with the inversion step-up circuit.
As a further improvement on the present invention, the trigger circuit includes triode, the second transformer and silicon-controlled；It is described
The base stage of triode is connected with the microcontroller, emitter ground connection, collector and the armature winding of second transformer
Cathode is connected, and the anode of the armature winding of second transformer is connected with the 4th external voltage；Second transformer
The anode of secondary pole winding be connected with silicon-controlled control pole, the silicon-controlled minus earth, the silicon-controlled anode
It is connected with the earth-free one end of the charge and discharge capacitance.
As a further improvement on the present invention, the microcontroller have the first output terminal and second output terminal, described first
Output terminal be connected with the inversion step-up circuit with control the charging stage and keep the stage duration, the second output terminal with
The trigger circuit is connected with the duration for controlling discharge regime.
Compared with prior art, the invention has the advantages that：The present invention is by microcontroller to charging stage, electric discharge
Stage, holding stage are controlled, and the frequency of the high-voltage pulse of output is accurately controlled, improves the one of output waveform
Cause property and stability, and will not be influenced by outer work condition, device aging, electric power thus supplied etc..Also, the present invention uses inversion
Booster circuit charges to charge and discharge capacitance, it can be ensured that charge and discharge capacitance reaches electric discharge normal voltage, and passes through amplitude discrimination electricity
Road ensure that the stability of the capacitance voltage, therefore, can further improve the stability of output waveform, has substantially increased striking
Success rate.
Description of the drawings
Fig. 1 is the circuit diagram of arc welding arc ignition circuit of the present invention；
Fig. 2 is the oscillogram of the voltage of subelement in arc welding arc ignition circuit of the present invention；
Fig. 3 is the selected parts of the datasheet of current mode controller UC3843 in the present invention.
Specific embodiment
Below with reference to specific embodiment shown in the drawings, the present invention will be described in detail.But these embodiments are simultaneously
The present invention is not limited, structure that those of ordinary skill in the art are made according to these embodiments, method or functionally
Transformation is all contained in protection scope of the present invention.
According to Fig. 1 and Fig. 2, the present invention provides a kind of arc welding arc ignition circuit, for generating high frequency voltage to draw
Fire electric arc.The arc welding arc ignition circuit includes：
High-voltage charge and discharge road 10, including charge and discharge capacitance C4, one end ground connection of the charge and discharge capacitance C4；
Inversion step-up circuit 20 is connected with the charge and discharge capacitance C4, to turn low level direct current in the charging stage
High level alternating current is turned to charge to charge and discharge capacitance C4；
Amplitude discrimination circuit 30 is connected with the high-voltage charge and discharge road 10, to judge the charging in the charge and discharge capacitance C4
Whether voltage has reached electric discharge normal voltage；And also it is connected with the inversion step-up circuit 20, in charge and discharge capacitance C4
When reaching electric discharge normal voltage so that inversion step-up circuit 20 is stopped, to stop charging to charge and discharge capacitance C4；
Trigger circuit 40 is connected with the charge and discharge capacitance C4, in discharge regime and the charge and discharge capacitance C4 shapes
Into access so that charge and discharge capacitance discharges, so as to form high-voltage pulse, striking is carried out；
Single chip circuit 50, including microcontroller N1, the microcontroller N1 and the inversion step-up circuit 20, trigger circuit 40
It is connected, to be timed control to charging stage, discharge regime and holding stage.
So as to charging stage, discharge regime and be kept for the stage be timed herein by microcontroller N1, microcontroller N1 is not
During work, entire circuit does not work, when microcontroller N1 starts to work, the charging stage, and microcontroller N1 control inversion boosting electricity
Road 20 works, and charges to charge and discharge capacitance, meanwhile, amplitude discrimination circuit 30 is monitored the voltage of charge and discharge capacitance C4；
It charging after a period of time, the voltage in charge and discharge capacitance C4 reaches electric discharge normal voltage, and amplitude discrimination circuit 30 is connected, from
And transmit a signal to inversion step-up circuit 20 so that inversion step-up circuit 20 disconnects, and the charging stage terminates, in charge and discharge capacitance C4
Voltage remain unchanged；
Microcontroller N1 control discharge regimes start, and microcontroller N1 controls trigger circuit 40 is connected, so as to the trigger circuit
Access is formed between 40 and charge and discharge capacitance C4, so that the charge and discharge capacitance C4 discharges to form high-voltage pulse；
After discharge regime, entire circuit enters the holding stage, and inversion step-up circuit 20 does not work, and determines when the holding stage
When after, again into the charging stage, and carry out above-mentioned cycle, until striking success.
Therefore, the present invention controls charging stage, discharge regime, holding stage by microcontroller N1, to output
The frequency of high-voltage pulse is accurately controlled, and improves the consistency and stability of output waveform, and will not be by extraneous work
The influence of condition, device aging, electric power thus supplied etc..Also, the present invention carries out charge and discharge capacitance C4 using inversion step-up circuit 20
Charging, it can be ensured that charge and discharge capacitance C4 reaches electric discharge normal voltage, and ensure that the capacitance voltage by amplitude discrimination circuit 30
Therefore stability, can further improve the stability of output waveform, substantially increase the success rate of striking.
Specifically, the amplitude discrimination circuit 30 includes, the bleeder circuit being connected with the charge and discharge capacitance C4, three ends are adjustable
Voltage-stablizer A4 and optocoupler OP1.The input terminal of the three-terminal voltage regulator A4 is connected with the bleeder circuit, ground connection termination
Ground, output terminal are connected with the input cathode of the optocoupler OP1.The input anode of the optocoupler OP1 and the first external voltage V1
It is connected, and the input anode of the optocoupler OP1 is connected by first resistor R1 with the input cathode of optocoupler OP1, it is described
The output anode of optocoupler OP1 is connected with the second external voltage V2, and output cathode passes through the 6th diode and the inversion boosting
Circuit 20 is connected.
When the input terminal of the three-terminal voltage regulator A4 reaches certain voltage, the exportable burning voltage of output terminal.
In present embodiment, the model TL430 of the three-terminal voltage regulator A4, therefore in the defeated of the three-terminal voltage regulator A4
Enter end when reaching the voltage of about 2.5V, the voltage of the exportable about 2V of output terminal；And in the input of the three-terminal voltage regulator A4
When end is unable to reach 2.5V, output terminal is equivalent to open circuit.
From the foregoing, it can be understood that the input anode of the optocoupler OP1 is connected with the first external voltage V1, and pass through the first electricity
Resistance R1 is connected with the input cathode of optocoupler OP1, and the input cathode of the optocoupler OP1 is then with the three-terminal voltage regulator A4's
Output terminal is connected.Then, when the output terminal of the three-terminal voltage regulator A4 is open circuit, the input anode of the optocoupler OP1
It is connected with input cathode by first resistor R1, is the first external voltage V1 so as to which voltage is equal, and optocoupler OP1's is defeated
Enter pole and be equivalent to a diode, when both end voltage is equal, diode is not turned on, and optocoupler OP1 does not work, then optocoupler OP1
Output stage disconnects, the output cathode Non voltage output of the optocoupler OP1；When the three-terminal voltage regulator A4 output terminals export about
During voltage for 2V, then the input stage both ends of optocoupler OP1 form voltage difference, diode current flow, by first resistor R1 short circuits, optocoupler
OP1 works, and causes the output stage conducting of optocoupler OP1, then output cathode output high level (the i.e. second external electricity of optocoupler OP1
Press V2) to the inversion step-up circuit 20.With this, the amplitude discrimination circuit 30, which can reach, differentiates the voltage in charge and discharge capacitance C4
Effect.In the present embodiment, the second external voltage V2 is 3.3V, then when optocoupler OP1 works, optocoupler OP1 is to described
Inversion step-up circuit 20 flows into the high level of the 3.3V.
In present embodiment, using optocoupler OP1 in amplitude discrimination circuit 30, there is electrical isolation.That is, make high-pressure side
(circuits such as high-voltage charge and discharge circuit) and low-pressure side (including the circuits such as single chip circuit 50, inversion boosting) carry out electrical isolation,
High-voltage pulse is avoided to generate interference to work such as microcontroller N1.
Also, it is proved by testing, under the premise of can ensureing that striking is successful, the attainable minimum safe voltage of institute is
900V then in present embodiment, by taking the charging voltage of 900V as an example, is calculated.Therefore, required for the charge and discharge capacitance C4
The voltage being filled with is 900V.Then bleeder circuit described above include the 11st resistance R11 and the 12nd resistance R12, the described tenth
One resistance R11 and the 12nd resistance R12 are mutually connected from beginning to end, and are connected in parallel on the both ends of the charge and discharge capacitance C4.Then described
The voltage got on 12 resistance R12 is the input terminal voltage of the three-terminal voltage regulator A4.Therefore, in order to enable
When voltage in charge and discharge capacitance C4 reaches maximum voltage 900V, the output terminal of three-terminal voltage regulator A4 could be exported,
Therefore the resistance value of the 11st resistance R11 is about 20M Ω, and the resistance value of the 12nd resistance R12 is about 56K Ω, so as to
So that when charge and discharge capacitance C4 reaches 900V, the partial pressure on the 12nd resistance R12 reaches 2.5V, so as to controllable described
The voltage that the output terminal output of three-terminal voltage regulator A4 is about 2V.
Therefore, the amplitude discrimination circuit 30 in the present invention, can be to charge and discharge by the cooperation of three-terminal voltage regulator A4 and optocoupler OP1
Voltage in capacitance C4 is monitored, and when the voltage in charge and discharge capacitance C4 reaches 900V, and the input of optocoupler OP1 is cloudy
Extremely exportable high level is to inversion step-up circuit 20 so that inversion step-up circuit 20 stops filling charge and discharge capacitance C4 immediately
Electricity prevents the voltage in charge and discharge capacitance C4 excessive or damages circuit.
The inversion step-up circuit 20 includes inverter circuit and inverse-excitation converting circuit, and the inverter circuit converts direct current
For alternating current, the inverse-excitation converting circuit is bringing the voltage up rapidly to charge to charge and discharge capacitance C4.It is described inverse
Become source electrode ground connection, grid and the current-mode that circuit includes current mode controller A1, NMOS tube VT1, the NMOS tube VT1
The output terminal of formula controller A1 is connected.In the present embodiment, the source electrode of the NMOS tube VT1 is connect by the 7th resistance R7
Ground.The inverse-excitation converting circuit includes the first transformer T1, and the armature winding of the first transformer T1 is connected to the third
Between the drain electrode of external voltage V3 and NMOS tube VT1, and the anode of the armature winding of the first transformer T1 and described the
Three external voltage V3 are connected.
The inverter circuit is may make up by core collocation peripheral circuit of the current mode controller A1, specifically,
In present embodiment, model UC3843, UC3843 are that domestic application is wider used by the current mode controller A1
A kind of general current control mode pulse width modulator, so-called current source PWM device is to carry out adjusting pulsewidth by feedback current.
The input terminal of pwm comparator is directly compared with the signal for flowing through outputting inductance coil current with error amplifier output signal
Compared with making the inductance peak point current tracking error voltage change of output so as to adjust duty ratio and change.Due to having voltage in structure
Ring, electric current loop bicyclic system, therefore, voltage regulation factor, load regulation and the transient response characteristic of Switching Power Supply all have
It improves, is more satisfactory novel controller.
As shown in Figure 1,6 feet of a kind of basic circuit for inverter circuit of the present invention, wherein current mode controller A1 are
OUTPUT is connected by the 6th resistance R6 with the grid of NMOS tube VT1, and output or not output voltage are to control the NMOS tube
VT1's cut-offs.2 feet, that is, VFB is connected with amplitude discrimination circuit 30 described above and microcontroller N1, the inverter circuit to be controlled to open
Begin or be stopped, and 2 foot starts for low level, i.e., only when the voltage for inputting 2 feet is low level, the current-mode
Formula controller A1 can just start to work.In addition, 2 foot is grounded by the 4th resistance R4.Specifically, current mode controller A1
2 feet be connected with the output cathode of optocoupler OP1 in the amplitude discrimination circuit 30, so as to according to described above, when amplitude discrimination electricity
When road 30 detects that the voltage in charge and discharge capacitance C4 reaches 900V, the output terminal of optocoupler OP1 conducting and to the electricity
The 2 foot input high levels (i.e. the second external voltage V2) of stream mode controller A1, so that the inversion step-up circuit 20 stops
It only works, and stops charging into the charge and discharge capacitance C4.
The current mode controller A1 can generate rectangular wave pulse, and the amplitude of the rectangular wave pulse is by 7 feet, that is, Vi's
DC input voitage determines；Its duty ratio is determined by the input voltage of 2 feet；Its reverse frequency is by inversion resistance RT and inversion capacitance
CT determines that one end of the inversion resistance RT is connected to the 8 feet i.e. VREF of the current mode controller A1, other end connection 4
Foot, that is, RT/CT, one end connection 4 feet, that is, RT/CT of the inversion capacitance CT, other end ground connection.So as to the Controlled in Current Mode and Based
The reverse frequency f of device A1 is：
Also, in the present embodiment, by adjusting the size of inversion resistance RT and inversion capacitance CT, RT=15K, CT=
1nF, then be defined to 120kHz by the reverse frequency, and cycle T is about 9 μ S.
In addition, the duty ratio of the current mode controller is determined by 2 foot voltages, in the case where 1 foot is vacant, such as
2 foot voltage of fruit is more than chip interior reference voltage 2.5V, and then chip stops output, then exported if less than 2.5V it is set most
Big space rate.Wherein, since in present embodiment, the inversion capacitance of the current mode controller A1 is 1nF, then such as Fig. 3 institutes
Show, by inquiring " deadtime vs Ct " table, it is about 0.5 μ S that can obtain dead time, then maximum duty cycle D=td/T is approximately equal to
50%.Certainly, it is the datasheet references of current mode controller A1 model UC3843 chips in the present invention above
It obtains, in practical applications, then can be by the debugging to circuit, the output frequency for finally determining the current mode controller is
120KHz, the waveform of duty ratio 50%.
It should be noted that in the present embodiment, the input voltage of 7 feet, that is, Vi is 12V, therefore, this embodiment party
Current mode controller A1 in formula can generate amplitude as 12V, duty ratio 50%, and frequency is the rectangular wave of 120kHz.
In addition, the connection mode of other pins of the current mode controller A1 is as follows：1 foot, that is, COMP is hanging；3
Foot, that is, Isense is connected by the 9th resistance R9 with the source electrode of the NMOS tube VT1, to detect electric current；5 feet, that is, GROUND
Ground connection；So that the current mode controller A1 normal works.
Therefore, rectangular wave caused by the current mode controller A1 generates on-off action, institute to the NMOS tube VT1
State NMOS tube VT1 also according to the frequency of 120kHz turn off, so as to the inverter circuit third external voltage V3 can be passed through it is straight
Galvanic electricity is reverse into the pulse that frequency is 120kHz.In the present embodiment, the value of the third external voltage V3 is 24V, therefore
The pulse of 24V, 120kHz can be formed in the armature winding of the first transformer T1.
In addition, further include the first filter circuit in the inverter circuit, first filter circuit include the first capacitance C1,
Second resistance R2, the first diode D1；The first capacitance C1 and second resistance R2 is parallel with one another and one end is connected to institute
State third external voltage V3, the other end is connected to the cathode of the first diode D1, the anode of the first diode D1 with
The drain electrode of the NMOS tube VT1 is connected.The first capacitance C1, second resistance R2 and the first diode D1 can form RCD filters
Wave circuit is filtered peak voltage in voltage signal so that whole system is more stable.
The secondary windings of the first transformer T1 includes the first secondary windings, and the inverse-excitation converting circuit further includes
Second diode D2；The cathode of first secondary windings is connected with the anode of the second diode D2, and the described 2nd 2
The cathode of pole pipe D2 is connected to charge to the charge and discharge capacitance C4 with described earth-free one end of charge and discharge capacitance C4.
The number of turn of first secondary windings and the equal turn numbers of the armature winding, and the second diode D2
Anode is connected to the cathode of first secondary windings, so as to constitute the inverse-excitation converting circuit, the inverse-excitation converting circuit
It can be to being high voltage pulse, and quick charge is carried out to charge and discharge capacitance C4 by the impulse transfer of 24V.Specifically, it is analyzed as follows：
Since the both ends of transformer are equivalent to two inductance, for convenience of explanation, below by the first transformer T1's
Armature winding is denoted as inductance L1, and the first secondary windings of the first transformer T1 is denoted as inductance L2.It is connected in the NMOS tube VT1
Period, third external voltage V3, that is, 24V voltages flow through the inductance L1 of the transformer, then the effect due to inductance in itself, flows through
The electric current of the armature winding of first transformer T1 can be linearly increasing, is deposited so as to which first transformer T1 can convert electrical energy into magnetic energy
Storage is in inductance L1.It can be seen from figure 1 that the first secondary windings of the first transformer T1 and the Same Name of Ends of armature winding on the contrary,
So as to may be such that the second diode D2 ends when reverse-biased, no current passes through in inductance L2.
And during the NMOS tube VT1 is disconnected, the electric current for flowing through inductance L1 becomes zero, and stores the magnetic energy in inductance L1
By in Mutual Inductance Coupling to inductance L2, and cause the second diode D2 positively biaseds and conducting, so as to which first transformer T1 discharges
Energy, and in quick storage to charge and discharge capacitance C4.Therefore, the first transformer T1 is actually that a primary and secondary are tight
The inductor that close coupling is closed.
And in practical applications, in the case where third external voltage V3 is 24V, the first time of the first transformer T1
The voltage of grade winding can reach within 1000V, so as to carry out quick charge to the charge and discharge capacitance C4, and ensure described fill
Discharge capacity C4 is quickly filled with to 900V.
The inversion step-up circuit 20 further includes voltage source circuit, and the voltage source circuit includes the first transformer T1
Second subprime winding, the number of turn of the second subprime winding is the half of the armature winding.In the present embodiment, it is described
The anode of second subprime winding is connected by the second capacitance C2 with the amplitude discrimination circuit 30.Therefore, the voltage source circuit is
The first external voltage V1 described above is constituted, without separately connecing voltage source so that entire circuit is simpler clear.
Also, the voltage source circuit includes the 4th diode D4, the anode and described first of the 4th diode D4
The cathode of the second subprime winding of transformer T1 is connected, and cathode is connected with the second capacitance C2, electric current to be prevented to be inverted.
In addition, the second capacitance C2 is connected by the 8th resistance R8 with the amplitude discrimination circuit 30.
The trigger circuit 40 includes triode VT3, the second transformer T2 and silicon-controlled VT2；The base of the triode VT3
Pole is connected with the microcontroller N1, emitter ground connection, the cathode phase of collector and the armature winding of the second transformer T2
Connection, the anode of the armature winding of the second transformer T2 are connected with the 4th external voltage V4；The second transformer T2
The anode of secondary pole winding be connected with the control pole of silicon-controlled VT2, the minus earth of the silicon-controlled VT2 is described silicon-controlled
The anode of VT2 is connected with described earth-free one end of charge and discharge capacitance C4.
The silicon-controlled VT2 is equivalent to a switch, when the control pole of the silicon-controlled VT2 adds forward voltage, institute
The anode of silicon-controlled VT2 and cathode conducting are stated, then in the present embodiment, the charge and discharge capacitance C4 discharges immediately, is drawn
Arc.
In the present embodiment, the discharge regime is controlled by microcontroller N1.The microcontroller N1 and triode VT3
Base stage be connected, when the base stage of the triode VT3 receives high level, the collector of the triode VT3 and transmitting
Pole is connected, and the 4th external voltage V4 has the armature winding that electric current flows through the second transformer T2, so as to the second transformer T2's
Secondary windings also generates electric current, and adds to the control pole of the silicon-controlled VT2 so that anode and the cathode conducting of silicon-controlled VT2,
Discharge regime starts.The 4th external voltage V4 is 24V, and the control pole of the relatively silicon-controlled VT2 of voltage is excessive, therefore passes through the
Two transformer T2 are depressured, and the number of turn between the armature winding and secondary windings of the second transformer T2 is 24：5.Certainly,
When the base stage of the triode VT3 does not receive high level, the triode VT3 is disconnected, the cathode of the silicon-controlled VT2
And anode also disconnects, the charge and discharge capacitance C4 does not discharge.
In addition, the trigger circuit 40 further includes third diode D3, the anode of the third diode D3 and described the
The anode of the secondary windings of two transformer T2 is connected, and prevents electric current reverse-biased；Also, the trigger circuit 40 further includes the second filter
Wave circuit, second filter circuit include third capacitance C3 and the tenth resistance R10, the third capacitance C3 and the tenth resistance
R10 is parallel with one another and one end is connected to the control pole of silicon-controlled VT2, and the other end is connected to the cathode of silicon-controlled VT2, with to voltage
It is filtered so that circuit work is more stablized.
Finally, the single chip circuit 50 is to the charging stage of entire arc welding arc ignition circuit, discharge regime, holding stage
It is controlled, and controls entire output duration.The microcontroller N1 has the first output terminal and second output terminal, and described first is defeated
Outlet be connected with the inversion step-up circuit 20 with control the charging stage and keep the stage duration, the second output terminal with
The trigger circuit 40 is connected with the duration for controlling discharge regime.
Specifically, the first output terminal of the microcontroller N1 passes through the 2 of the 5th diode D5 and current mode controller A1
Foot is connected, and the second output terminal of the microcontroller N1 passes through the 5th resistance R5 and the triode of trigger circuit 40 described above
The base stage of VT3 is connected.
First, into charging stage, the timing signal of the first output terminal output 4ms of the microcontroller N1.Such as above-mentioned institute
It states, since 2 feet of the current mode controller A1 work for low level, then in the timing signal of the 4ms, the microcontroller
The first output terminal output low level of N1 so that the current mode controller A1 starts to work.It is described after 4ms timings
First output terminal is converted to high level output, and the second output terminal of the microcontroller N1 exports the high level of 13 μ s immediately,
Triode VT3 conductings are controlled, into discharge regime, so that the charge and discharge capacitance C4 discharges.And then, in discharge regime
After enter the holding stage, the second output terminal of the microcontroller N1 exports the low level of 16ms, also, the monolithic immediately
The first output terminal of machine N1 also keeps high level until the timing of 16ms terminates.So far charge and discharge capacitance C4, which is completed, once fills
Electricity and discharge cycle, are denoted as a striking period.After a cycle, repeat the above-mentioned period so that entire circuit follows
Ring works, until striking success or microcontroller N1 are stopped.
Therefore, the exportable amplitude of entire circuit is 900V, and pulse width is 4ms (13 μ s numerical value are too small to be ignored), duty
Than the impulse waveform for 20% (13 μ s numerical value are too small to be ignored).
The microcontroller N1 is controlled by enable signal, and enable signal controls the microcontroller N1 start-up operations and terminates work
Make, and the timing total duration of the microcontroller N1 is controlled to be no more than 50 above-mentioned periods, this is because prolonged output is high
Pulse is pressed, for entire circuit and welding machine, is likely to that insulating layer is caused to puncture, so as to cause harm.Certainly, if pulse
Period is very few, then can influence the success rate of striking, therefore, is no more than according to the high-voltage pulse of previous experiences and data analysis striking
50 above-mentioned periods.
It is to prevent discharge regime duration long thus to controllable in addition, why selecting the duration of the discharge regime of 13 μ s
Silicon VT2 is damaged.
The model LPC902 of the microcontroller N1, therefore 1 foot, that is, VDD of the microcontroller N1 meets external voltage 3.3V, 2
Foot, that is, P0.2/KBI2 connects enable signal, and 3 feet, that is, P0.0/KBI0 is connected for the first output terminal with the current mode controller A1
It connecing, 4 feet, that is, P1.5/-RST meets the 5th external voltage V5 by the 13rd resistance R13, and the 5th external voltage V5 is 3.3V, and 5
Foot, that is, P0.6/KBI6 is connected for second output terminal and with the base stage of the triode VT3,6 feet, that is, P0.5/KBI5 ground connection, 7 feet
That is P0.4/KBI4 is connected with the cathode of the negative input end of the optocoupler OP1,8 feet, that is, VSS ground connection.
By foregoing description, with reference to Fig. 2, the workflow of entire arc welding arc ignition circuit is illustrated：
At the beginning, when enable signal disconnects, microcontroller N1 does not work, the 3 feet output high level of microcontroller N1, due to electric current
2 feet of mode controller A1 are that low level starts, and therefore, entire circuit does not start；
Then, the t1 times arrive, and enable signal is opened, and microcontroller N1 starts to work, 5 feet output low level, trigger circuit 40
It does not work；And 3 feet of microcontroller N1 start to export the low level of lasting 4ms, and the output of the optocoupler OP1 in amplitude discrimination circuit 30
Grade disconnects, and also exports low level, then it is low level that 2 feet of current mode controller A1, which receive, at this time, Controlled in Current Mode and Based
Device A1 starts to work；
After current mode controller A1 starts to work, the rectangular pulse of the 6 feet output 120kHz of current mode controller A1
Wave, and by inverse-excitation converting circuit, quick charge is carried out to charge and discharge capacitance C4；
After charge and discharge capacitance C4 is full of, the t2 times arrive, and pass through bleeder circuit so that three ends of amplitude discrimination circuit 30 can
The input terminal of voltage-stablizer A4 is adjusted to reach cut-in voltage, the output terminal of the three-terminal voltage regulator A4 starts to export, and causes light
The cathode of the output stage of coupling OP1 starts to export high level, so that the current mode controller A1 is stopped, at this point,
Voltage in the charge and discharge capacitance C4 keeps 900V；
The 4ms of 3 feet of the microcontroller N1 is timed to, i.e. the t3 times arrive, and 3 feet of microcontroller N1 switch to high level, and
5 feet of the microcontroller N1 start export 13 μ s high level so that trigger circuit 40 works, then the cathode of silicon-controlled VT2 and
Anode is connected, and the charge and discharge capacitance C4 starts to discharge；
After the timing of 13 μ s, the release of voltage in charge and discharge capacitance C4 finishes, and reaches the t4 times, and the 5 of microcontroller N1
Foot restores low level again, and 3 feet then keep high level and start the timing of 16ms；
The timing of 3 feet of microcontroller N1 terminates, and the t5 times arrive, and 3 feet of microcontroller N1 start to export low level, go forward side by side
The above-mentioned cycle of row；
Entire arc welding arc ignition circuit persistently carries out charging stage, discharge regime and is kept for the stage, until striking success or
Enable signal disappears.
In conclusion the arc welding arc ignition circuit includes high-voltage charge and discharge circuit, inversion step-up circuit 20, amplitude discrimination circuit
30th, trigger circuit 40, single chip circuit 50, so as to can quickly be filled to charge and discharge capacitance C4 by inversion step-up circuit 20
Electricity, trigger circuit 40 carries out repid discharge to charge and discharge capacitance C4, and passes through microcontroller N1 to charging stage, discharge regime, guarantor
The stage of holding is controlled, so as to can ensure that the charge and discharge capacitance C4 is filled to 900V, and to the charging time and can put
The electric time is accurately controlled, so that final impulse waveform is relatively stable, is greatly improved the success rate of striking.
Also, using three-terminal voltage-stabilizing adjustable device, optocoupler OP1 and bleeder circuit composition amplitude discrimination circuit 30 to charging in the present invention
Voltage in capacitance is detected, and can accurately detect the accurately voltage in charging capacitor, and by high-pressure section and list
Piece machine N1 etc. is separated so that high-pressure section does not interfere with the work of microcontroller N1, current mode controller A1 so that entire electricity
Arc-welding arc ignition circuit is relatively stable.
It should be appreciated that although this specification is described in terms of embodiments, but not each embodiment only includes one
A independent technical solution, this description of the specification is merely for the sake of clarity, and those skilled in the art should will say
For bright book as an entirety, the technical solution in each embodiment may also be suitably combined to form those skilled in the art can
With the other embodiment of understanding.
Those listed above is a series of to be described in detail only for feasibility embodiment of the invention specifically
Bright, they are not to limit the scope of the invention, all equivalent implementations made without departing from skill spirit of the present invention
Or change should all be included in the protection scope of the present invention.
Claims (9)
1. a kind of arc welding arc ignition circuit, for generating high frequency voltage with the electric arc that ignites, it is characterised in that：The arc welding striking
The course of work of circuit includes charging stage, discharge regime and is kept for the stage；The arc welding arc ignition circuit includes：
High-voltage charge and discharge circuit, including charge and discharge capacitance, charge and discharge capacitance one end ground connection；
Inversion step-up circuit is connected with the charge and discharge capacitance, low level direct current is converted to high electricity in the charging stage
Usual friendship galvanic electricity is to charge to charge and discharge capacitance；
Amplitude discrimination circuit is connected with the high-voltage charge and discharge road, to judge whether the charging voltage of charge and discharge capacitance reaches electric discharge
Normal voltage；And be connected with the inversion step-up circuit, to cause inversion when charge and discharge capacitance reaches electric discharge normal voltage
Booster circuit is stopped；
Trigger circuit is connected with the charge and discharge capacitance, causes charge and discharge to form access in discharge regime and charge and discharge capacitance
Capacitance discharges to form high-voltage pulse；
Single chip circuit, including microcontroller, the microcontroller is connected with the inversion step-up circuit, trigger circuit, with to filling
Electric stage, discharge regime and holding stage are timed control, and control charging stage, discharge regime and kept for the stage continuous
Cycle is carried out until striking success.
2. arc welding arc ignition circuit according to claim 1, it is characterised in that：The amplitude discrimination circuit includes and the charge and discharge
Bleeder circuit, three-terminal voltage regulator and the optocoupler that capacitance is connected；The input terminal of the three-terminal voltage regulator with it is described
Bleeder circuit is connected, and ground terminal ground connection, output terminal is connected with the input cathode of the optocoupler；The input anode of the optocoupler
It is connected with the first external voltage, and the input anode of the optocoupler is connected by first resistor with the input cathode of optocoupler
It connects, the output anode of the optocoupler is connected with the second external voltage, and output cathode is connected with the inversion step-up circuit.
3. arc welding arc ignition circuit according to claim 1, it is characterised in that：The inversion step-up circuit includes inversion electricity
Road and inverse-excitation converting circuit, the inverter circuit include current mode controller, NMOS tube, the NMOS tube source electrode ground connection,
Grid is connected with the output terminal of the current mode controller；The inverse-excitation converting circuit includes the first transformer, and described the
The armature winding of one transformer is connected between third external voltage and the drain electrode of NMOS tube, and first transformer is first
The anode of grade winding is connected with the third external voltage.
4. arc welding arc ignition circuit according to claim 3, it is characterised in that：The inverter circuit further includes the first filtering
Circuit, first filter circuit include the first capacitance, second resistance and the first diode；First capacitance and the second electricity
It hinders parallel with one another and one end and is connected to the third external voltage, the other end is connected to the cathode of first diode, described
The anode of first diode is connected with the drain electrode of the NMOS tube.
5. arc welding arc ignition circuit according to claim 3, it is characterised in that：The secondary windings packet of first transformer
The first secondary windings is included, and the inverse-excitation converting circuit further includes the second diode；The cathode of first secondary windings with
The anode of second diode is connected, cathode and the earth-free one end phase of the charge and discharge capacitance of second diode
It connects to charge to the charge and discharge capacitance.
6. arc welding arc ignition circuit according to claim 3, it is characterised in that：The inversion step-up circuit further includes voltage
Source circuit, the secondary windings of first transformer include second subprime winding, and the voltage source circuit further includes described second
Secondary windings, the anode of the second subprime winding are connected by the second capacitance with the amplitude discrimination circuit.
7. arc welding arc ignition circuit according to claim 6, it is characterised in that：The amplitude discrimination circuit includes and the charge and discharge
Bleeder circuit, three-terminal voltage regulator and the optocoupler that capacitance is connected；The input terminal of the three-terminal voltage regulator with it is described
Bleeder circuit is connected, and ground terminal ground connection, output terminal is connected with the input cathode of the optocoupler；The input anode of the optocoupler
It is connected with one end of the anode of second capacitance far from second subprime winding, and the input for passing through first resistor and optocoupler is cloudy
Pole is connected, and the output anode of the optocoupler is connected with the second external voltage, output cathode and the inversion step-up circuit phase
Connection.
8. arc welding arc ignition circuit according to claim 1, it is characterised in that：The trigger circuit includes triode, the
Two transformers and silicon-controlled；The base stage of the triode is connected with the microcontroller, emitter ground connection, collector and described the
The cathode of the armature winding of two transformers is connected, anode and the 4th external voltage phase of the armature winding of second transformer
Connection；The anode of the secondary pole winding of second transformer is connected with silicon-controlled control pole, and the silicon-controlled cathode connects
Ground, the silicon-controlled anode are connected with the earth-free one end of the charge and discharge capacitance.
9. arc welding arc ignition circuit according to claim 1, it is characterised in that：The microcontroller have the first output terminal and
Second output terminal, first output terminal be connected with the inversion step-up circuit with control the charging stage and keep the stage when
Long, the second output terminal is connected with the trigger circuit with the duration for controlling discharge regime.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611047781.5A CN106334857B (en) | 2016-11-23 | 2016-11-23 | A kind of arc welding arc ignition circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611047781.5A CN106334857B (en) | 2016-11-23 | 2016-11-23 | A kind of arc welding arc ignition circuit |
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| CN106334857A CN106334857A (en) | 2017-01-18 |
| CN106334857B true CN106334857B (en) | 2018-06-19 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201611047781.5A Active CN106334857B (en) | 2016-11-23 | 2016-11-23 | A kind of arc welding arc ignition circuit |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| TWI817432B (en) * | 2022-04-07 | 2023-10-01 | 宏碁股份有限公司 | Power delivery system with electric arc suppression |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2614152A1 (en) * | 1976-04-02 | 1977-10-20 | Stk Gmbh | Welding arc striking pulse - produced by glow tube discharging capacitor through pulse transformer on reaching breakdown voltage |
| CN1061176A (en) * | 1990-11-09 | 1992-05-20 | 山门自动化工业股份有限公司 | Surface automatic welding machine circuit |
| SE9102961L (en) * | 1991-10-14 | 1993-04-15 | Esab Ab | WELD STREAMKELLA FOR EXCHANGE STROEMLJUSBAAG WELDING |
| CN2276390Y (en) * | 1996-07-19 | 1998-03-18 | 清华大学 | High-frequence arc striking device for contravariant switch type arc processing power |
| CN102218579A (en) * | 2011-06-17 | 2011-10-19 | 上海威特力焊接设备制造股份有限公司 | Environment-friendly high-frequency arc ignition generator |
| CN206356704U (en) * | 2016-11-23 | 2017-07-28 | 昆山华恒焊接股份有限公司 | A kind of arc welding arc ignition circuit |
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2016
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