Welding machine control circuit and welding machine

Abstract

The application belongs to the technical field of electric welding machines, and particularly relates to an electric welding machine control circuit and an electric welding machine. The electric welding machine control circuit comprises a feedback circuit, a power setting circuit, a PID adjusting circuit, a PWM pulse modulation circuit, a PWM enabling circuit, a PWM switching circuit and a control circuit. In a PWM slow-rising control mode, the control circuit controls the electric welding machine to start or stop working through the PWM enabling circuit. In a PWM fast control mode, the control circuit opens or closes the error signal input PWM pulse modulation circuit through the PWM switching circuit to control the PWM pulse modulation circuit to output a PWM signal or a single-level signal, so that the electric welding machine meets different current response requirements in different arc striking conditions.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric welding machines, and particularly relates to an electric welding machine control circuit and an electric welding machine. BACKGROUND

[0002] At present, the control circuit of the electric welding machine adopts the PWM pulse width modulation technology to drive and control the output current and voltage. When the electric welding machine ignites the welding arc each time, the soft start process of starting and pulse width spreading through a PWM pulse modulation circuit is fixedly required, and the establishment process of the output current is relatively fixed. Therefore, the PWM control mode of the existing electric welding machine control circuit is fixed and single, so that the electric welding machine cannot meet the different current response requirements when the arc is ignited under different requirements. SUMMARY

[0003] The main purpose of the application is to provide an electric welding machine control circuit and an electric welding machine, which aims to solve the problem that the PWM control mode of the traditional electric welding machine control circuit is fixed and single, so that the electric welding machine cannot meet the different current response requirements when the arc is ignited under different requirements.

[0004] The first aspect of the embodiment of the application provides an electric welding machine control circuit, which comprises: a feedback circuit, which is used for sampling the output power of the electric welding machine and outputting a feedback signal; a power given circuit, which is used for providing a given signal for controlling the output power of the electric welding machine; a PID adjusting circuit, which is connected with the feedback circuit and the power given circuit, and is used for outputting an error signal according to the feedback signal and the given signal; a PWM pulse modulation circuit, which is connected with the PID adjusting circuit, and is used for outputting a PWM signal to drive the electric welding machine to work according to the error signal; and a PWM enabling circuit, which is connected with the PWM pulse modulation circuit, and is used for outputting an enabling signal to enable the PWM pulse modulation circuit to start working.

[0005] The electric welding machine control circuit further comprises: a PWM switch circuit, which is connected with the output end of the PID adjusting circuit, and is used for opening or closing the input of the error signal to the PWM pulse modulation circuit; and a control circuit, which is connected with the power given circuit, the PWM enabling circuit and the PWM switch circuit, and is used for controlling the power given circuit to output the given signal; and is further used for controlling the PWM enabling circuit to output the enabling signal or stop outputting the enabling signal to control the electric welding machine to start or stop working in the PWM slow control mode; and is further used for controlling the PWM switch circuit to open or close the input of the error signal to the PWM pulse modulation circuit to control the PWM pulse modulation circuit to output the PWM signal or a single level signal in the PWM fast control mode.

[0006] In one of the embodiments, the single level signal is a high level signal or a low level signal.

[0007] In one of the embodiments, a PWM driving circuit is further included, which is connected with the PWM pulse modulation circuit, and is configured to drive the output working current of the electric welding machine according to the PWM signal.

[0008] In one of the embodiments, the control circuit is configured to select the PWM slow control mode or the PWM fast control mode according to the user input.

[0009] In one of the embodiments, in the PWM slow control mode, the PWM pulse modulation circuit needs to be re-enabled each time the electric welding machine ignites an arc, and the current response process of the arc ignition presents a slow rising trend.

[0010] In one of the embodiments, in the PWM slow control mode, when the electric welding machine ignites an arc, the control circuit controls the PWM enabling circuit to enable the PWM pulse modulation circuit to start, so that the current response process of the arc ignition presents a slow rising trend.

[0011] In one of the embodiments, in the PWM fast control mode, when the PWM switch circuit closes the output of the error signal, the PWM pulse modulation circuit outputs a single level signal, and then when the electric welding machine re-ignites an arc, the PWM switch circuit opens the output of the error signal, and the PWM pulse modulation circuit outputs a PWM signal, so that the current response process of the arc ignition presents a fast trend.

[0012] In one of the embodiments, the PWM enabling circuit includes a second switch tube, a second resistor, a third resistor, a fourth resistor, a first capacitor, and a first anti-reverse diode.

[0013] The control end of the second switch tube is connected with the control circuit, the first conduction end of the second switch tube is connected with the first end of the second resistor and the first end of the third resistor, the second end of the second resistor and the second end of the third resistor are commonly connected with a voltage source, the second conduction end of the second switch tube is grounded, the anode of the first anti-reverse diode is connected with the second conduction end of the second switch tube, the cathode of the first anti-reverse diode is connected with the PWM pulse modulation circuit, and the fourth resistor and the first capacitor are connected in parallel and then connected in series between the cathode of the first anti-reverse diode and the ground.

[0014] In one of the embodiments, the single level signal drives the electric welding machine to stop outputting the working current.

[0015] The second aspect of the present application provides an electric welding machine including the electric welding machine control circuit in any of the above embodiments.

[0016] The beneficial effects of this application embodiment compared with the prior art are as follows: The above-mentioned welding machine control circuit sets up a PWM switching circuit and a PWM enabling circuit. The PWM switching circuit is used to turn on or off the error signal input to the PWM pulse modulation circuit, and the PWM enabling circuit is used to output an enabling signal to enable the PWM pulse modulation circuit to start working. By controlling the PWM switching circuit and the PWM enabling circuit through the control circuit, in the PWM slow-rise control mode, the PWM enabling circuit is controlled to output an enabling signal or stop outputting an enabling signal to control the welding machine to start or stop working. In the PWM fast control mode, the PWM switching circuit is controlled to turn on or off the error signal input to the PWM pulse modulation circuit to control the PWM pulse modulation circuit to output a PWM signal or a single-level signal. Thus, the welding machine meets the different current response requirements when igniting the arc under different needs, enriches the PWM control mode of the welding machine control circuit, expands the working application range of the welding machine, and improves the arc ignition performance of the welding machine. Attached Figure Description

[0017] Figure 1 A schematic diagram of the principle of a welding machine control circuit provided in an embodiment of this application;

[0018] Figure 2 A schematic diagram of the principle of a welding machine control circuit provided in another embodiment of this application;

[0019] Figure 3 The circuit diagram is shown for a welding machine control circuit provided in one embodiment of this application. Detailed Implementation

[0020] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0021] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0022] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0023] In addition, the terms "first", "second", etc. are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or an ordered ranking of the indicated technical features. Thus, features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0024] Referring to Figure 1 An embodiment of the present application provides an electric welding machine control circuit, which comprises a feedback circuit 100, a power given circuit 200, a PID adjusting circuit 300, a PWM pulse modulation circuit 400 and a PWM enabling circuit 500. The feedback circuit 100 is used to sample the output power of the electric welding machine and output a feedback signal, wherein the output power refers to the output voltage and / or output current of the electric welding machine, and the feedback signal can also be a real-time feedback signal of voltage and / or current. The power given circuit 200 is used to provide a given signal of the output power of the electric welding machine, for example, a given current signal when the electric welding machine is normally working. The PID adjusting circuit 300 is connected with the feedback circuit 100 and the power given circuit 200 respectively, and is used to output an error signal according to the feedback signal and the given signal. The PID adjusting circuit 300 is, for example, a PID regulator, which can calculate the error signal according to the feedback signal and the given signal. The PWM pulse modulation circuit 400 is connected with the PID adjusting circuit 300, and is used to output a PWM signal according to the error signal output by the PID adjusting circuit 300, wherein the PWM signal is used to drive the output working current of the electric welding machine. The PWM enabling circuit 500 is connected with the PWM pulse modulation circuit 400, and is used to output an enabling signal to enable the PWM pulse modulation circuit 400 to start working.

[0025] Referring to Figure 1 An embodiment of the present application provides an electric welding machine control circuit, which further comprises a PWM switch circuit 600 and a control circuit 700. The PWM switch circuit 600 is connected with the output end of the PID adjusting circuit 300, and is used to open or close the input of the error signal to the PWM pulse modulation circuit 400. When the input of the error signal to the PWM pulse modulation circuit 400 is closed, the PWM pulse modulation circuit 400 cannot output the PWM signal to drive the electric welding machine to normally work.

[0026] The control circuit 700 is connected with the power setting circuit 200, the PWM enabling circuit 500 and the PWM switching circuit 600 respectively, and the control circuit 700 is configured to control the power setting circuit 200 to output a given signal. The control circuit 700 is also configured to control the PWM enabling circuit 500 to output an enabling signal or stop outputting the enabling signal in the PWM slow control mode, so as to control the electric welding machine to start or stop working. The control circuit 700 is also configured to control the PWM switching circuit 600 to open or close the error signal input PWM pulse modulation circuit 400 in the PWM fast control mode, so as to control the PWM pulse modulation circuit 400 to output a PWM signal or a single level signal. When the PWM pulse modulation circuit 400 outputs the single level signal, the PWM pulse modulation circuit 400 cannot output a normal PWM signal, and thus cannot drive the electric welding machine to work normally.

[0027] The electric welding machine control circuit in the above embodiment controls the output of the electric welding machine driving signal by setting the PWM switching circuit 600 and the PWM enabling circuit 500. The PWM switching circuit 600 is configured to open or close the error signal input PWM pulse modulation circuit 400, and the PWM enabling circuit 500 is configured to output an enabling signal to enable the PWM pulse modulation circuit 400 to start working. The control circuit 700 controls the PWM switching circuit 600 and the PWM enabling circuit 500, so that the PWM enabling circuit 500 outputs an enabling signal or stops outputting the enabling signal in the PWM slow control mode, so as to control the electric welding machine to start or stop working, and the PWM switching circuit 600 opens or closes the error signal input PWM pulse modulation circuit 400 in the PWM fast control mode, so as to control the PWM pulse modulation circuit 400 to output a normal PWM signal or a single level signal. Thus, the electric welding machine can meet different current response requirements when the electric welding machine is ignited under different requirements, the PWM control mode of the electric welding machine control circuit is enriched, the working application range of the electric welding machine is expanded, and the ignition performance of the electric welding machine is improved.

[0028] Please refer to Figure 1 In an embodiment, the single level signal output by the PWM pulse modulation circuit 400 is a single high level signal or a single low level signal. Neither the single high level signal nor the single low level signal is a normal PWM signal, and thus neither can drive the electric welding machine to work normally. In this case, the electric welding machine stops outputting.

[0029] Please refer to Figure 2 In an embodiment, the electric welding machine control circuit further comprises a PWM driving circuit 800 connected with the PWM pulse modulation circuit 400, and configured to drive the electric welding machine to output a working current according to the PWM signal output by the PWM pulse modulation circuit 400.

[0030] Please refer to Figure 1 or Figure 2In an embodiment, the control circuit 700 is configured to be in a PWM slow control mode or a PWM fast control mode according to different welding requirements of the electric welding machine. Here, the different welding requirements of the electric welding machine can be the relevant parameters set by the user at the beginning of welding or during welding, or the relevant parameters automatically set by the device according to the type of workpiece, for example, the response speed of the electric welding machine arc current when the arc is ignited.

[0031] Referring to Figure 1 or Figure 2 In an embodiment, in the PWM slow control mode, when the electric welding machine ignites the arc, the control circuit 700 controls the PWM enable circuit 500 to enable the PWM pulse modulation circuit 400 to start, so that the current response process of the electric welding machine arc ignition presents a relatively slow upward trend.

[0032] Referring to Figure 1 or Figure 2 In an embodiment, in the PWM fast control mode, when the PWM switch circuit 600 closes the output of the error signal, the PWM pulse modulation circuit 400 outputs a single level signal, and then when the electric welding machine re-ignites the arc, the PWM switch circuit 600 opens the output of the error signal, and the PWM pulse modulation circuit 400 outputs the PWM signal, so that the current response process of the arc ignition presents a fast trend. Since the PWM pulse modulation circuit 400 is still in working state when the PWM switch circuit 600 closes the output of the error signal, the electric welding machine does not need to enable the PWM pulse modulation circuit 400 to restart through the PWM enable circuit 500 when the electric welding machine next time ignites the arc, so that the current response process of the electric welding machine arc ignition presents a relatively fast upward trend.

[0033] Referring to Figure 3 In an embodiment, the PWM switch circuit 600 includes a first switch tube Q1 and a first resistor R1, the control end of the first switch tube Q1 is connected with the control circuit 700, the first conduction end of the first switch tube Q1 is connected with the first end of the first resistor R1, the second end of the first resistor is connected with the output end of the PID regulation circuit 300, the second conduction end of the first switch tube Q1 is grounded, and the first resistor R1 is a pull-down resistor. When the first switch tube Q1 is turned on, the level of the output end of the PID regulation circuit 300 is pulled down, that is, the error signal input to the PWM pulse modulation circuit 400 is closed.

[0034] Specifically, referring to Figure 3 In an embodiment, the first switch tube Q1 is an NPN type transistor, the base of the first switch tube Q1 is connected with the control circuit 700, the collector of the first switch tube Q1 is connected with the first end of the first resistor R1, and the emitter of the first switch tube Q1 is grounded.

[0035] Referring to Figure 3In an embodiment, the PWM enabling circuit 500 comprises a second switch Q2, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1 and a first anti-reverse diode D1. The control terminal of the second switch Q2 is connected with the control circuit 700. The first conduction terminal of the second switch Q2 is connected with the first terminal of the second resistor R2 and the first terminal of the third resistor R3. The second terminal of the second resistor R2 and the second terminal of the third resistor R3 are commonly connected with the voltage source VCC. The second conduction terminal of the second switch Q2 is grounded. The anode of the first anti-reverse diode D1 is connected with the second conduction terminal of the second switch Q2. The cathode of the first anti-reverse diode D1 is connected with the PWM pulse modulation circuit 400. The fourth resistor R4 and the first capacitor C1 are connected in parallel and then connected in series between the cathode of the first anti-reverse diode D1 and the ground. The second resistor R2 and the third resistor R3 are used as pull-up resistors. The fourth resistor R4 is used as a voltage dividing resistor. The first capacitor C1 is used for filtering. The first anti-reverse diode D1 is used to prevent the voltage from flowing back from the PWM pulse modulation circuit 400.

[0036] Specifically, refer to Figure 3 In an embodiment, the second switch Q2 is an NPN type transistor. The base of the second switch Q2 is connected with the control circuit 700. The collector of the second switch Q2 is connected with the first terminal of the second resistor R2 and the first terminal of the third resistor R3. The emitter of the second switch Q2 is grounded.

[0037] In an embodiment, the single level signal cannot normally drive the output working current of the electric welding machine. The single level signal output by the PWM pulse modulation circuit 400 is a single high level signal or a single low level signal. Neither the single high level signal nor the single low level signal is a normal PWM signal and neither can drive the electric welding machine to work normally. In this case, the electric welding machine stops outputting the working current.

[0038] In order to better illustrate the working principle of the electric welding machine control circuit of the embodiments of the present application, the following will be described in combination with specific conditions. Refer to Figure 3 In the PWM slow rising control mode, when the electric welding machine is ignited each time, the control circuit 700 controls the PWM enabling circuit 500 to output an enabling signal to enable the PWM pulse modulation circuit 400. The PWM pulse modulation circuit 400 outputs a PWM signal to the PWM driving circuit 800, thereby controlling the electric welding machine to start working. When the electric welding machine does not need to be ignited, the control circuit 700 controls the PWM enabling circuit 500 to stop outputting the enabling signal to the PWM pulse modulation circuit 400. The PWM pulse modulation circuit 400 stops outputting the PWM signal. When the electric welding machine is ignited again, it is necessary to re-enable the PWM pulse modulation circuit 400 to start. The current response process of the ignition presents a slow rising trend.

[0039] In the PWM fast control mode, the input of the error signal of the PWM pulse modulation circuit 400 is turned on or turned off by the PWM switch circuit 600 to control the output of the electric welding machine. When the electric welding machine starts to arc each time, the control circuit 700 outputs a low-level signal to the PWM switch circuit 600, at this time, the first switch tube Q1 is cut off, the input of the error signal of the PWM pulse modulation circuit 400 is turned on, and the PWM pulse modulation circuit 400 starts to work to output a normal PWM signal. When the welding is stopped, the control circuit 700 outputs a high-level signal to the PWM switch circuit 600, at this time, the first switch tube Q1 is turned on, the output end of the PID regulation circuit 300 is pulled to the ground, that is, the input of the error signal of the PWM pulse modulation circuit 400 is turned off, at this time, the PWM pulse modulation circuit 400 still maintains the working state, but the output signal is no longer a normal PWM signal, but a single high-level signal or a single low-level signal, which cannot normally drive the electric welding machine, so the electric welding machine stops outputting. When the electric welding machine arcs again, the PWM pulse modulation circuit 400 does not need to be restarted, and the current response process of the electric welding machine shows a relatively fast trend.

[0040] The electric welding machine control circuit of the embodiment of the application controls the output of the driving signal of the electric welding machine by setting the PWM switch circuit 600 and the PWM enable circuit 500, wherein the PWM switch circuit 600 is used to turn on or turn off the input of the error signal to the PWM pulse modulation circuit 400, and the PWM enable circuit 500 is used to output an enable signal to enable the PWM pulse modulation circuit 400 to start to work. The PWM switch circuit 600 and the PWM enable circuit 500 are controlled by the control circuit 700, so that in the PWM slow control mode, the PWM enable circuit 500 is controlled to output the enable signal or stop outputting the enable signal to control the electric welding machine to start or stop to work, and in the PWM fast control mode, the PWM switch circuit 600 is controlled to turn on or turn off the input of the error signal to the PWM pulse modulation circuit 400 to control the PWM pulse modulation circuit 400 to output a normal PWM signal or a single-level signal, so that the electric welding machine meets different current response requirements when arcing under different requirements, the PWM control mode of the electric welding machine control circuit is enriched, the working application range of the electric welding machine is expanded, and the arcing performance of the electric welding machine is improved.

[0041] The second aspect of the application provides an electric welding machine comprising the electric welding machine control circuit provided in the first aspect of the embodiment of the application.

[0042] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit them; although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A welding machine control circuit, comprising: a feedback circuit for sampling output power of the welding machine and outputting a feedback signal; a power setting circuit for providing a setting signal for controlling the output power of the welding machine; a PID regulating circuit connected with the feedback circuit and the power setting circuit for outputting an error signal according to the feedback signal and the setting signal; a PWM pulse modulation circuit connected with the PID regulating circuit for outputting a PWM signal according to the error signal to drive the welding machine to work; and a PWM enabling circuit connected with the PWM pulse modulation circuit for outputting an enabling signal to enable the PWM pulse modulation circuit to start working; characterized in that the welding machine control circuit further comprises: a PWM switch circuit connected with an output terminal of the PID regulating circuit for opening or closing the error signal input to the PWM pulse modulation circuit; and a control circuit connected with the power setting circuit, the PWM enabling circuit and the PWM switch circuit for controlling the power setting circuit to output the setting signal, for controlling the PWM enabling circuit to output or stop outputting the enabling signal to control the welding machine to start or stop working in a PWM slow-rising control mode, and for controlling the PWM switch circuit to open or close the error signal input to the PWM pulse modulation circuit to control the PWM pulse modulation circuit to output the PWM signal or a single-level signal in a PWM fast control mode. The single-level signal is a high-level signal or a low-level signal.

2. The electric welder control circuit of claim 1, wherein, The welding machine control circuit further comprises a PWM drive circuit connected with the PWM pulse modulation circuit for driving the welding machine to output working current according to the PWM signal.

3. The welding machine control circuit of claim 1, wherein, The control circuit controls the welding machine to work in the PWM slow-rising control mode or the PWM fast control mode according to an operation configuration input by a user.

4. The welding machine control circuit of any one of claims 1-3, wherein, In the PWM slow-rising control mode, when the welding machine ignites an arc, the control circuit controls the PWM enabling circuit to enable the PWM pulse modulation circuit to start, so that a current response process of igniting the arc presents a slow-rising trend.

5. The electric welder control circuit of claim 4 wherein, In the PWM fast control mode, when the PWM switch circuit closes the output of the error signal, the PWM pulse modulation circuit outputs a single-level signal, and then, when the welding machine re-ignites the arc, the PWM switch circuit opens the output of the error signal, and the PWM pulse modulation circuit outputs a PWM signal, so that the current response process of igniting the arc presents a fast trend.

6. The welding machine control circuit of claim 4, wherein, The PWM switch circuit comprises a first switch tube and a first resistor, a control terminal of the first switch tube is connected with the control circuit, a first conduction terminal of the first switch tube is connected with a first terminal of the first resistor, a second terminal of the first resistor is connected with an output terminal of the PID regulating circuit, and a second conduction terminal of the first switch tube is grounded.

7. The electric welder control circuit of any one of claims 1-3, wherein, The PWM enabling circuit comprises a second switch tube, a second resistor, a third resistor, a fourth resistor, a first capacitor and a first anti-reverse diode.

8. The welding machine control circuit of any one of claims 1-3, wherein, ​ The control end of the second switch tube is connected with the control circuit, the first conduction end of the second switch tube is connected with the first end of the second resistor and the first end of the third resistor, the second end of the second resistor and the second end of the third resistor are commonly connected with a voltage source, the second conduction end of the second switch tube is grounded, the anode of the first anti-reverse diode is connected with the second conduction end of the second switch tube, the cathode of the first anti-reverse diode is connected with the PWM pulse modulation circuit, the fourth resistor and the first capacitor are connected in parallel and then connected in series between the cathode of the first anti-reverse diode and the ground.

9. The welding machine control circuit of claim 2, wherein, The single level signal drives the electric welding machine to stop outputting working current.

10. An electric welder characterized by The electric welding machine control circuit comprises the electric welding machine control circuit according to any one of claims 1-9.

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