Welding current prefabrication adjusting and displaying system

Abstract

The utility model discloses a welding current prefabrication adjustment and display system which comprises a first signal input circuit, a second signal input circuit, a first switching circuit, a second switching circuit, an inverse proportion operational amplifier circuit and a display circuit. The output end of the first signal input circuit is respectively connected with the input end of the first switch circuit and the input end of the inverse proportion operational amplifier circuit, the output end of the first switch circuit is grounded, and the output end of the inverse proportion operational amplifier circuit is connected with the first input end of the display circuit; the output end of the second signal input circuit is connected with the input end of the second switching circuit and the second input end of the display circuit. The output end of the second switching circuit is connected with the control end of the first switching circuit. According to the utility model, current prefabricated adjusting parameters are set as negative display, and are converted into positive parameter indication during actual welding, so that a user is clear at a glance; and meanwhile, the adjustment time of a user is greatly shortened, and more accurate current control is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic circuits, in particular to a welding current prefabrication adjustment and display system. Background Art

[0002] In industrial applications, welding equipment is often used. Usually, before welding, the welding current is pre-set according to the welding requirements. However, the current pre-set of most welding equipment on the market only serves as an indication and cannot accurately display the actual welding current; at the same time, the current pre-set adjustment parameter is also a positive parameter indication, and the indication function is not intuitive.

[0003] If the preset display and the actual display are both positive, other people cannot clearly see the working status of the equipment except the user. Because the equipment has remote operation and welding power generation function, when welding load, the power generation power at the near end will be reduced. The near-end user of the equipment needs to know the status of the equipment more simply and clearly. This design saves the user the time to think about the specific status of the equipment. Summary of the invention

[0004] Aiming at the problem that welding equipment in the prior art cannot accurately display the actual welding current, the utility model proposes a welding current prefabrication adjustment and display system.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A welding current prefabrication adjustment and display system comprises a first signal input circuit, a second signal input circuit, a first switch circuit, a second switch circuit, a reverse proportional operational amplifier circuit and a display circuit;

[0007] The output end of the first signal input circuit is connected to the input end of the first switch circuit and the input end of the reverse proportional amplifier circuit respectively, the output end of the first switch circuit is grounded, and the output end of the reverse proportional amplifier circuit is connected to the first input end of the display circuit;

[0008] The output end of the second signal input circuit is connected to the input end of the second switch circuit and the second input end of the display circuit respectively, and the output end of the second switch circuit is connected to the control end of the first switch circuit.

[0009] Preferably, when the second signal input circuit has no second signal, the second switch circuit is turned on, thereby controlling the first switch circuit to be turned off; when the second signal input circuit has the second signal input, the second switch circuit is turned off, thereby controlling the first switch circuit to be turned on.

[0010] Preferably, the input signal of the first signal input circuit is a current prefabrication signal, and the input signal of the second signal input circuit is an actual welding current signal.

[0011] Preferably, the second signal input circuit includes a first comparator and a second comparator:

[0012] The first signal input terminal is respectively connected to one end of the first resistor, one end of the second resistor, and one end of the third resistor, the other end of the first resistor is respectively connected to one end of the first capacitor and the positive phase input terminal of the second comparator, the other end of the first capacitor is grounded, the negative phase input terminal of the second comparator and the output terminal of the second comparator are connected in parallel to one end of the sixth resistor, the other end of the sixth resistor is connected to one end of the seventh resistor, the other end of the seventh resistor and the control end of the seventh resistor are connected in parallel to the collector of the second triode, the positive phase input terminal of the third comparator, one end of the eighth resistor, and the negative electrode of the first diode, the other end of the eighth resistor and the positive electrode of the first diode are connected in parallel and then grounded;

[0013] The other end of the second resistor is grounded;

[0014] The other end of the third resistor is respectively connected to the negative phase input terminal of the first comparator and one end of the second capacitor; the positive phase input terminal of the first comparator is respectively connected to one end of the fourth resistor and one end of the fifth resistor, the other end of the fourth resistor is connected to the first power supply, and the other end of the fifth resistor is grounded; the positive voltage terminal of the first comparator is connected to the second power supply, and the negative voltage terminal of the first comparator is grounded; the output terminal of the first comparator and the other end of the second capacitor are connected in parallel to one end of the thirteenth resistor, one end of the fourteenth resistor, and one end of the fifteenth resistor.

[0015] Preferably, the first signal input circuit includes a fifth comparator and a twelfth resistor:

[0016] The positive phase input terminal of the fifth comparator is connected to the second signal input terminal; the negative phase input terminal of the fifth comparator is respectively connected to the control terminal of the twenty-second resistor, one end of the twenty-second resistor, and one end of the twenty-third resistor, and the other end of the twenty-third resistor is grounded; the output terminal of the fifth comparator and the other end of the twenty-second resistor are connected in parallel to one end of the eighteenth resistor, the other end of the eighteenth resistor is connected to one end of the twelfth resistor, the control terminal of the twelfth resistor and the other end of the twelfth resistor are connected in parallel to the cathode of the second diode, one end of the eleventh resistor, the collector of the first transistor, and one end of the twenty-first resistor.

[0017] Preferably, the inverse proportional operational amplifier circuit comprises a fourth comparator:

[0018] The positive input terminal of the fourth comparator is grounded, and the negative input terminal of the fourth comparator is respectively connected to the other end of the twenty-first resistor and one end of the twentieth resistor; the output terminal of the fourth comparator and the other end of the twentieth resistor are connected in parallel to one end of the nineteenth resistor.

[0019] Preferably, the resistance values ​​of the twentieth resistor and the twenty-first resistor are the same.

[0020] Preferably, the first switch circuit includes a first transistor:

[0021] The third power supply is connected to one end of the ninth resistor, the other end of the ninth resistor is respectively connected to one end of the tenth resistor and the collector of the third transistor, the other end of the tenth resistor is connected to the base of the first transistor, the emitter of the first transistor, the other end of the eleventh resistor, and the anode of the second diode are connected in parallel and then grounded.

[0022] Preferably, the second switch circuit includes a second transistor and a third transistor:

[0023] The emitter of the second triode is grounded, and the base of the second triode is connected to the other end of the thirteenth resistor; the other end of the fifteenth resistor is grounded, and the other end of the fourteenth resistor is connected to the base of the third triode, and the emitter of the third triode is grounded.

[0024] Preferably, the display circuit comprises a third comparator:

[0025] The output end of the third comparator and the negative phase input end of the third comparator are connected in parallel to one end of the seventeenth resistor, the other end of the seventeenth resistor, one end of the third capacitor, and the other end of the nineteenth resistor are connected in parallel to the output end, and the other end of the third capacitor is grounded.

[0026] In summary, due to the adoption of the above technical solution, compared with the prior art, the utility model has at least the following beneficial effects:

[0027] The utility model sets the pre-adjustment parameter of the current as a negative display, and converts it to a positive parameter indication during actual welding. The use of positive and negative data display can intuitively inform the actual state of the machine, so that the user can clearly know the working state of the equipment, and saves the user the time to think about the specific state of the equipment; at the same time, the nearly 1:1 linear display circuit also greatly reduces the user's adjustment time and realizes more accurate current control. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The figure is a schematic diagram of an exemplary welding current prefabrication adjustment and display system according to the utility model.

[0029] Figure 2It is a schematic diagram showing an exemplary current prefabrication signal and a real-time welding current signal according to the utility model.

[0030] Figure 3 The figure is a schematic diagram of the principle of a welding current prefabrication adjustment and display system according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with the embodiments and specific implementation methods. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0032] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0033] like Figure 1 As shown, the utility model provides a welding current prefabrication adjustment and display system, including a first signal input circuit, a second signal input circuit, a first switch circuit, a second switch circuit, a reverse proportional operational amplifier circuit and a display circuit.

[0034] The output end of the first signal input circuit is connected to the input end of the first switch circuit and the input end of the reverse proportional amplifier circuit respectively, the output end of the first switch circuit is grounded, and the output end of the reverse proportional amplifier circuit is connected to the first input end of the display circuit;

[0035] The output end of the second signal input circuit is connected to the input end of the second switch circuit and the second input end of the display circuit respectively, and the output end of the second switch circuit is connected to the control end of the first switch circuit.

[0036] In this embodiment, the signal input by the first signal input circuit is a current prefabricated signal, that is, a current magnitude preset before actual welding.

[0037] In this embodiment, the signal input by the second signal input circuit is a Hall signal, that is, a signal indicating whether the load is in contact.

[0038] In this embodiment, if the second signal input circuit does not have the second signal (real-time welding current signal), the second switch circuit is turned on, thereby controlling the first switch circuit to be turned off, and the second signal is short-circuited (grounded) through the second switch circuit, that is, the second signal will not be transmitted to the second input end of the display circuit; at this time, when the first signal input circuit has the first signal (current pre-set positive signal), because the first switch circuit is in the off state, the first signal input reverse proportional amplifier circuit performs amplitude flipping, becomes a negative signal and is transmitted to the first input end of the display circuit;

[0039] If the second signal input circuit inputs the second signal, the second switch circuit is turned off, thereby controlling the first switch circuit to be turned on, and the first signal input by the first signal input circuit will be short-circuited (grounded) through the first switch circuit, that is, the first signal cannot be transmitted to the display circuit after passing through the reverse proportional operational amplifier circuit (that is, the first signal is terminated to avoid signal overlapping interference); at this time, because the second switch circuit is in the off state, the second signal can only be transmitted to the second input end of the display circuit.

[0040] like Figure 2 As shown, when the first signal input circuit inputs the first signal and the second signal input circuit has no signal input, the current displayed by the display circuit is preset to a negative display (-300); when the first signal input circuit inputs the first signal and the second signal input circuit inputs the second signal, the current displayed by the display circuit is preset to a positive display (300).

[0041] like Figure 3 As shown, the second signal input circuit includes a first comparator U1, a second comparator U2 and an adjustable resistor R7, and the specific connection relationship is as follows:

[0042] The first signal input terminal (IN1) is respectively connected to one end of the first resistor R1, one end of the second resistor R2, and one end of the third resistor R3; the other end of the first resistor R1 is respectively connected to one end of the first capacitor C1 and the positive phase input terminal of the second comparator U2; the other end of the first capacitor C1 is grounded; the negative phase input terminal of the second comparator U2 and the output terminal of the second comparator U2 are connected in parallel to one end of the sixth resistor R6; the other end of the sixth resistor R6 is connected to one end of the adjustable resistor R7; the other end and the control end of the adjustable resistor R7 are connected in parallel to the collector of the second triode Q2, the positive phase input terminal of the third comparator U3 (the second input terminal of the display circuit), one end of the eighth resistor R8, and the cathode of the first diode D1; the other end of the eighth resistor R8 and the anode of the first diode D1 are connected in parallel to ground;

[0043] The other end of the second resistor R2 is grounded;

[0044] The other end of the third resistor R3 is respectively connected to the negative phase input end of the first comparator U1 and one end of the second capacitor C2; the positive phase input end of the first comparator U1 is respectively connected to one end of the fourth resistor R4 and one end of the fifth resistor R5, the other end of the fourth resistor R4 is connected to the first power supply VCC1, and the other end of the fifth resistor R5 is grounded; the positive voltage end of the first comparator U1 is connected to the second power supply VCC2, and the negative voltage end of the first comparator U1 is grounded; the output end of the first comparator U1 and the other end of the second capacitor C2 are connected in parallel to one end of the thirteenth resistor R13, one end of the fourteenth resistor R14, and one end of the fifteenth resistor R15.

[0045] In this embodiment, the first signal input circuit includes a fifth comparator U5 and a twelfth resistor R12 (adjustable resistor):

[0046] The positive phase input terminal of the fifth comparator U5 is connected to the second signal input terminal (IN2); the negative phase input terminal of the fifth comparator U5 is respectively connected to the control terminal of the twenty-second resistor R22, one end of the twenty-second resistor R22, and one end of the twenty-third resistor R23, and the other end of the twenty-third resistor R23 is grounded; the output terminal of the fifth comparator U5 and the other end of the twenty-second resistor R22 are connected in parallel to one end of the eighteenth resistor R18, the other end of the eighteenth resistor R18 is connected to one end of the twelfth resistor R12, the control terminal of the twelfth resistor R12 and the other end of the twelfth resistor R12 are connected in parallel to the cathode of the second diode D2, one end of the eleventh resistor R11, the collector of the first transistor Q1, and one end of the twenty-first resistor R21 (the input terminal of the reverse proportional operational amplifier circuit).

[0047] In this embodiment, the reverse proportional operational amplifier circuit includes a fourth comparator U4:

[0048] The positive phase input terminal of the fourth comparator U4 is grounded, and the negative phase input terminal of the fourth comparator U4 is respectively connected to the other end of the twenty-first resistor R21 and one end of the twentieth resistor R20; the output terminal of the fourth comparator U4 and the other end of the twentieth resistor R20 are connected in parallel to one end of the nineteenth resistor R19 (the first input terminal of the display circuit).

[0049] In this embodiment, in order to convert the amplitude of the first signal (the current preset positive signal) into a negative signal, the resistance values ​​of the twentieth resistor R20 and the twenty-first resistor R21 should be equal.

[0050] For the reverse operational amplifier circuit, the output voltage U = -(Rf / Rin)*Vin, where Rf is R20, Rin is R21, and Vin is the voltage at the power input terminal of R21. Therefore, positive and negative reversal can only occur when the resistance values ​​of R20 and R21 are equal, and there will be no change in signal amplification or reduction.

[0051] In this embodiment, the first switch circuit includes a first transistor Q1:

[0052] The third power supply VCC3 (generally the voltage is 15V) is connected to one end of the ninth resistor R9, the other end of the ninth resistor R9 is respectively connected to one end of the tenth resistor R10 and the collector of the third triode Q3, the other end of the tenth resistor R10 is connected to the base of the first triode Q1, the emitter of the first triode Q1, the other end of the eleventh resistor R11, and the anode of the second diode D2 are connected in parallel and then grounded.

[0053] In this embodiment, the second switch circuit includes a second transistor Q2 and a third transistor Q3:

[0054] The emitter of the second transistor Q2 is grounded, and the base of the second transistor Q2 is connected to the other end of the thirteenth resistor R13; the other end of the fifteenth resistor R15 is grounded, and the other end of the fourteenth resistor R14 is connected to the base of the third transistor Q3, and the emitter of the third transistor Q3 is grounded.

[0055] In this embodiment, the display circuit includes a third comparator U3:

[0056] The output end of the third comparator U3 and the negative phase input end of the third comparator U3 are connected in parallel to one end of the seventeenth resistor R17, the other end of the seventeenth resistor R17, one end of the third capacitor C3, and the other end of the nineteenth resistor R19 are connected in parallel to the output end (OUT), and the other end of the third capacitor C3 is grounded.

[0057] In this embodiment, the working principle of each circuit is as follows:

[0058] When in current preset display:

[0059] The second signal input circuit has no second signal input, that is, the Hall feedback signal is 0, U1 outputs +15V, at this time Q2, Q3 are turned on; because Q3 is turned on, the node voltage of R9, R10 is 0, so the base voltage of Q1 is 0, and Q1 is in the cut-off state. All transistors in the control circuit are selected as 8050 transistors, which are NPN transistors. The conduction condition of the modified transistor is that the emitter junction is forward biased and the collector junction is reverse biased.

[0060] When the first signal input circuit has a first signal input, the first signal enters the reverse proportional operational amplifier circuit after passing through U5, R18, and R12. At this time, the resistance values ​​of R21 and R20 are set to be equal. The first signal is amplitude-inverted and becomes a negative signal. After being transmitted to the display circuit, a negative signal (-300) is displayed in the current display.

[0061] Actual welding current display:

[0062] The second signal input circuit has a second signal input. At this time, the Hall feedback signal is greater than the voltage of the in-phase input terminal of U1, and U1 outputs -15V. At this time, Q2 and Q3 are turned off; because Q3 is turned off, the node voltage of R9 and R10 is high, so the base voltage of Q1 is high, about 0.7V, and is in the on state. All transistors in the control circuit are selected as 8050 transistors, which are NPN transistors. The conduction condition of the tube is that the emitter junction is forward biased and the collector junction is reverse biased.

[0063] Even if the first signal input circuit has a first signal input, when the first signal passes through U5, R18, and R12, because Q1 is turned on, the first signal is short-circuited, that is, the first signal is terminated here and will not be transmitted to the reverse proportional operational amplifier circuit and the display circuit, avoiding display interference of the first signal; at the same time, after the second signal passes through R1, U2, R7, and R8, because Q2 and Q3 are turned off, the second signal can only be displayed in the current display after passing through the display circuit, for example 300 (positive signal).

[0064] When the current is displayed in preset mode, the second signal is completely blocked by Q2 and Q3; when the actual welding current is displayed, the first signal is completely blocked by Q1 to avoid signal overlap interference; at the same time, the adjustable resistance of the preset and actual display can be set to match the ratio of the preset and actual display according to the actual situation in actual application, and the linear inertia can be as large as 1:1.

[0065] For example, if you want to achieve a 1:1 relationship between the pre-adjusted and actual displayed current parameters, the core lies in the linear ratio of the pre-adjusted adjustment parameters, which should be basically close to the actual output feedback. For the Hall sensor feedback (IN1) used at the load output end, the feedback signal has a good linear ratio as the current increases, so the difficulty is transferred to how to keep the linear ratio consistent with the linear ratio of the Hall feedback during no-load adjustment. Here, the potentiometer signal adjustment (IN2) is set, and the amplification ratio of the pre-adjusted given signal is adjusted to a suitable ratio through R22 (this ratio can be obtained after a large number of experimental comparisons) until the out end of U5 is 10V. At this time, adjust R12 to make the pre-adjusted value of the display table 300; then adjust within this range. When pre-adjusting -100, by adjusting the output current value of the system to 100A, the display table shows -115A, and through R7, the load display table shows 100A. In this way, -100, -200, and -300 are adjusted and optimized, and finally the overall linear presentation error is within 1%, which is relatively excellent.

[0066] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present invention, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A welding current prefabrication adjustment and display system, characterized in that , including a first signal input circuit, a second signal input circuit, a first switch circuit, a second switch circuit, a reverse proportional operational amplifier circuit and a display circuit; The output end of the first signal input circuit is connected to the input end of the first switch circuit and the input end of the reverse proportional amplifier circuit respectively, the output end of the first switch circuit is grounded, and the output end of the reverse proportional amplifier circuit is connected to the first input end of the display circuit; The output end of the second signal input circuit is connected to the input end of the second switch circuit and the second input end of the display circuit respectively, and the output end of the second switch circuit is connected to the control end of the first switch circuit.

2. A welding current prefabrication adjustment and display system as claimed in claim 1, characterized in that When there is no second signal in the second signal input circuit, the second switch circuit is turned on, thereby controlling the first switch circuit to be turned off; when the second signal input circuit has the second signal input, the second switch circuit is turned off, thereby controlling the first switch circuit to be turned on.

3. A welding current prefabrication adjustment and display system as claimed in claim 1, characterized in that ,The input signal of the first signal input circuit is a current prefabricated signal, and the input signal of the second signal input circuit is an actual welding current signal.

4. A welding current prefabrication adjustment and display system as claimed in claim 1, characterized in that , the second signal input circuit includes a first comparator and a second comparator: The first signal input terminal is respectively connected to one end of the first resistor, one end of the second resistor, and one end of the third resistor, the other end of the first resistor is respectively connected to one end of the first capacitor and the positive phase input terminal of the second comparator, the other end of the first capacitor is grounded, the negative phase input terminal of the second comparator and the output terminal of the second comparator are connected in parallel to one end of the sixth resistor, the other end of the sixth resistor is connected to one end of the seventh resistor, the other end of the seventh resistor and the control end of the seventh resistor are connected in parallel to the collector of the second triode, the positive phase input terminal of the third comparator, one end of the eighth resistor, and the negative electrode of the first diode, the other end of the eighth resistor and the positive electrode of the first diode are connected in parallel and then grounded; The other end of the second resistor is grounded; The other end of the third resistor is respectively connected to the negative phase input terminal of the first comparator and one end of the second capacitor; the positive phase input terminal of the first comparator is respectively connected to one end of the fourth resistor and one end of the fifth resistor, the other end of the fourth resistor is connected to the first power supply, and the other end of the fifth resistor is grounded; the positive voltage terminal of the first comparator is connected to the second power supply, and the negative voltage terminal of the first comparator is grounded; the output terminal of the first comparator and the other end of the second capacitor are connected in parallel to one end of the thirteenth resistor, one end of the fourteenth resistor, and one end of the fifteenth resistor.

5. A welding current prefabrication adjustment and display system as claimed in claim 1, characterized in that , the first signal input circuit includes a fifth comparator and a twelfth resistor: The positive phase input terminal of the fifth comparator is connected to the second signal input terminal; the negative phase input terminal of the fifth comparator is respectively connected to the control terminal of the twenty-second resistor, one end of the twenty-second resistor, and one end of the twenty-third resistor, and the other end of the twenty-third resistor is grounded; the output terminal of the fifth comparator and the other end of the twenty-second resistor are connected in parallel to one end of the eighteenth resistor, the other end of the eighteenth resistor is connected to one end of the twelfth resistor, the control terminal of the twelfth resistor and the other end of the twelfth resistor are connected in parallel to the cathode of the second diode, one end of the eleventh resistor, the collector of the first transistor, and one end of the twenty-first resistor.

6. A welding current prefabrication adjustment and display system as claimed in claim 1, characterized in that , the reverse proportional operational amplifier circuit includes a fourth comparator: The positive input terminal of the fourth comparator is grounded, and the negative input terminal of the fourth comparator is respectively connected to the other end of the twenty-first resistor and one end of the twentieth resistor; the output terminal of the fourth comparator and the other end of the twentieth resistor are connected in parallel to one end of the nineteenth resistor.

7. A welding current prefabrication adjustment and display system as claimed in claim 6, characterized in that , the resistance values ​​of the 20th resistor and the 21st resistor are the same.

8. A welding current prefabrication adjustment and display system as claimed in claim 1, characterized in that , the first switch circuit includes a first transistor: The third power supply is connected to one end of the ninth resistor, the other end of the ninth resistor is respectively connected to one end of the tenth resistor and the collector of the third transistor, the other end of the tenth resistor is connected to the base of the first transistor, the emitter of the first transistor, the other end of the eleventh resistor, and the anode of the second diode are connected in parallel and then grounded.

9. A welding current prefabrication adjustment and display system as claimed in claim 1, characterized in that , the second switch circuit includes a second triode and a third triode: The emitter of the second triode is grounded, and the base of the second triode is connected to the other end of the thirteenth resistor; the other end of the fifteenth resistor is grounded, and the other end of the fourteenth resistor is connected to the base of the third triode, and the emitter of the third triode is grounded.

10. A welding current prefabrication adjustment and display system as claimed in claim 1, characterized in that , the display circuit includes a third comparator: The output end of the third comparator and the negative phase input end of the third comparator are connected in parallel to one end of the seventeenth resistor, the other end of the seventeenth resistor, one end of the third capacitor, and the other end of the nineteenth resistor are connected in parallel to the output end, and the other end of the third capacitor is grounded.

Images