Power supply circuit and laser welding equipment

Abstract

The utility model provides a power supply circuit and laser welding equipment. The power supply circuit comprises a voltage reduction module, a filtering module, a sampling module, a comparison module and a switch module, the first end of the filtering module, the first end of the sampling module and the input end of the voltage reduction module are connected with an input power supply, the output end of the voltage reduction module is connected with the first end of the switch module, the second end of the switch module is connected with a load, and the second end of the filtering module is connected with the second end of the sampling module and the ground. The third end of the sampling module is connected with the first input end of the comparison module, the second input end of the comparison module is connected with reference voltage, and the output end of the comparison module is connected with the control end of the switch module; in the circuit, the ripple voltage of the filter module is sampled and compared with the reference voltage, and the switch module is turned off when the sampled voltage is greater than the reference voltage, so that a post-stage circuit is prevented from being damaged, and the working safety of the circuit is improved.

Description

Technical Field

[0001] The embodiments of the utility model relate to the technical field of electronic circuits, and in particular to a power supply circuit and laser welding equipment. Background Art

[0002] Laser welding equipment is usually used in fields with high requirements for welding quality and precision, such as automobile manufacturing, aerospace, electronic equipment, etc. Its advantages include fast welding speed, small heat-affected zone, high weld quality, etc. Laser welding equipment uses laser to generate a high-energy-density heat source, and achieves welding by irradiating the surface of the workpiece, thereby achieving a high-quality and high-precision welding process.

[0003] At present, the power input requirement for laser welding equipment is usually an input voltage no greater than 277Vac, while the existing power supply has 220Vac input specifications and 380Vac input specifications. If the user does not carefully read the manual during actual use and directly connects the input line to the two live wires of 380Vac, that is, mistakenly connects to 380Vac three-phase electricity as the input power supply, it will cause the laser, chiller, laser auxiliary source and other internal accessories inside the laser welding equipment to be overvoltage and damaged. Utility Model Content

[0004] The embodiments of the utility model provide a power supply circuit and laser welding equipment, which can disconnect the power supply of the load when the input power voltage is too large, thereby improving the circuit safety.

[0005] In a first aspect, an embodiment of the utility model provides a power supply circuit, comprising: a step-down module, a filtering module, a sampling module, a comparison module and a switch module; the first end of the filtering module, the first end of the sampling module and the input end of the step-down module are all used to connect to an input power supply, the output end of the step-down module is connected to the first end of the switch module, the second end of the switch module is used to connect to a load, the second end of the filtering module is respectively connected to the second end of the sampling module and the ground, the third end of the sampling module is connected to the first input end of the comparison module, the second input end of the comparison module is used to connect to a reference voltage, and the output end of the comparison module is the control end of the switch module; wherein the filtering module is used to filter the input power supply to generate a ripple voltage; the step-down module is used to step down the input power supply; the sampling module is used to output a sampling voltage to the comparison module based on the ripple voltage; the comparison module is used to output a control signal to the switch module based on the sampling voltage and the reference voltage; the switch module is used to establish or disconnect the connection between the output end of the step-down module and the load based on the control signal.

[0006] In some embodiments, the switch module also includes a first switch unit and a second switch unit; the first end of the first switch unit is connected to the output end of the comparison module, the second end of the first switch unit is connected to the control end of the second switch unit, the first end of the second switch unit is connected to the output end of the step-down module, and the second end of the second switch unit is used to connect the load; the first switch unit is used to be turned on or off based on the control signal; the second switch unit is used to disconnect the connection between the output end of the step-down module and the load when the first switch unit is turned on, and to establish the connection between the output end of the step-down module and the load when the first switch unit is turned off.

[0007] In some embodiments, the first switch unit includes a switch tube Q1 and a resistor R6; the control end of the switch tube Q1 is connected to the output end of the comparison module, the first end of the switch tube Q1 is respectively connected to the first end of the resistor R6 and the control end of the second switch unit, the second end of the switch tube Q1 is grounded, and the second end of the resistor R6 is connected to the first power supply.

[0008] In some embodiments, the second switch unit includes a switch tube Q3 and a relay K1; the control end of the switch tube Q3 is connected to the second end of the first switch unit, the first end of the switch tube Q3 is connected to the first end of the relay K1, the second end of the switch tube Q3 is grounded, the second end of the relay K1 is connected to the first power supply, the third end of the relay K1 is connected to the output end of the buck module, and the fourth end of the relay K1 is used to connect the load.

[0009] In some embodiments, the filtering module includes a capacitor C1; the first end of the capacitor C1 is respectively connected to the input power supply, the input end of the step-down module and the first end of the sampling module, and the second end of the capacitor C1 is respectively connected to the second end of the sampling module and ground.

[0010] In some embodiments, the sampling module includes a resistor R1, a resistor R2, a resistor R3, a resistor R4 and an operational amplifier U1; the first end of the resistor R2 is connected to the first end of the filtering module, the second end of the resistor R2 is respectively connected to the first end of the resistor R4 and the first input end of the operational amplifier U1, the first end of the resistor R1 is connected to the second end of the filtering module, the second end of the resistor R1 is respectively connected to the first end of the resistor R3 and the second input end of the operational amplifier U1, the second end of the resistor R3 is grounded, and the output end of the operational amplifier U1 is respectively connected to the first input end of the comparison module and the second end of the resistor R4.

[0011] In some embodiments, the comparison module includes a comparator U2, a diode D3 and a resistor R5; the first input end of the comparator U2 is respectively connected to the third end of the sampling module and the cathode of the diode D3, the second input end of the comparator U2 is used to connect the reference voltage, the output end of the comparator U2 is respectively connected to the first end of the resistor R5 and the anode of the diode D3, and the second end of the resistor R5 is connected to the control end of the switch module.

[0012] In some embodiments, the step-down module includes a switch tube Q2, a diode D1, a diode D2, an inductor L1 and a capacitor C2; the first end of the switch tube Q2 is connected to the input power supply, the second end of the switch tube Q2 is respectively connected to the first end of the inductor L1 and the cathode of the diode D1, the anode of the diode D1 is grounded, the second end of the inductor L1 is connected to the anode of the diode D2, the cathode of the diode D2 is respectively connected to the first end of the switch module and the first end of the capacitor C2, and the second end of the capacitor C2 is grounded.

[0013] In some embodiments, the power supply circuit also includes a rectifier module; the first end of the rectifier module is used to connect the input power supply, and the second end of the rectifier module is respectively connected to the first end of the filter module, the first end of the sampling module and the input end of the step-down module.

[0014] In the second aspect, an embodiment of the utility model further provides a laser welding device, which includes: a laser, a chiller, and a power supply circuit as described in any embodiment of the first aspect; the output end of the power supply circuit is respectively connected to the laser and the chiller.

[0015] Compared with the prior art, the utility model has the following beneficial effects: Different from the prior art, the utility model provides a power supply circuit and laser welding equipment, including: a step-down module, a filter module, a sampling module, a comparison module and a switch module; the first end of the filter module, the first end of the sampling module and the input end of the step-down module are all used to connect the input power supply, the output end of the step-down module is connected to the first end of the switch module, the second end of the switch module is used to connect the load, the second end of the filter module is respectively connected to the second end of the sampling module and the ground, the third end of the sampling module is connected to the first input end of the comparison module, the second input end of the comparison module is used to connect the reference voltage, and the output end of the comparison module is the control end of the switch module; in this circuit, by sampling the ripple voltage of the filter module and comparing it with the reference voltage, and turning off the switch module when the sampled voltage is greater than the reference voltage, it is ensured that the subsequent circuit is not damaged and the safety of the circuit operation is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements / modules and steps with the same reference numerals in the drawings are represented as similar elements / modules and steps. Unless otherwise specified, the figures in the drawings do not constitute proportional limitations.

[0017] Figure 1 It is a structural block diagram of a power supply circuit provided by an embodiment of the utility model;

[0018] Figure 2 It is a structural schematic diagram of a power supply circuit provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0019] The utility model is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the utility model, but do not limit the utility model in any form. It should be pointed out that for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the utility model. These all fall within the scope of protection of the utility model.

[0020] For ease of understanding of the present application, the present application is described in more detail below in conjunction with the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those generally understood by those skilled in the art of the present application. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not used to limit the present application. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0021] It should be noted that, if there is no conflict, the various features in the embodiments of the present utility model can be combined with each other, and all are within the scope of protection of this application. In addition, although the functional module division is performed in the device schematic, in some cases, the module division can be different from that in the device. In addition, the words "first", "second", etc. used in this article do not limit the data and execution order, but only distinguish the same items or similar items with basically the same functions and effects.

[0022] In a first aspect, the present invention provides a power supply circuit 100. Figure 1 The power supply circuit 100 includes: a step-down module 10, a filter module 20, a sampling module 30, a comparison module 40 and a switch module 50.

[0023] The first end of the filter module 20, the first end of the sampling module 30 and the input end of the buck module 10 are all used to connect to the input power supply 200, the output end of the buck module 10 is connected to the first end of the switch module 50, the second end of the switch module 50 is used to connect to the load 300, the second end of the filter module 20 is respectively connected to the second end of the sampling module 30 and the ground GND, the third end of the sampling module 30 is connected to the first input end of the comparison module 40, the second input end of the comparison module 40 is used to connect to the reference voltage, and the output end of the comparison module 40 is the control end of the switch module 50.

[0024] Among them, the filtering module 20 is used to filter the input power supply 200 to generate a ripple voltage; the buck module 10 is used to step down the input power supply 200; the sampling module 30 is used to output a sampling voltage to the comparison module 40 based on the ripple voltage; the comparison module 40 is used to output a control signal to the switch module 50 based on the sampling voltage and the reference voltage; the switch module 50 is used to establish or disconnect the connection between the output end of the buck module 10 and the load 300 based on the control signal.

[0025] The input power supply 200 includes an AC power supply of 220Vac or an AC power supply of 380Vac. The AC power supply can be output to the first end of the filter module 20 and the first end of the step-down module 10 after rectification. The filter module 20 includes one of a capacitive device or an inductive device, that is, a capacitor or an inductor. After the AC power supply is initially connected, the filter module 20 starts filtering. During the filtering process, if the capacitor starts to charge and discharge, the voltage across the capacitor will change during the charging and discharging process. The voltage across the capacitor is also the ripple voltage.

[0026] In the comparison module 40, if the voltage of the input power supply 200 is greater than the threshold value allowed by the power supply circuit, the sampling voltage output by the sampling module 30 will be higher than the reference voltage, and if the voltage of the input power supply 200 is less than the threshold value, the sampling voltage output by the sampling module 30 will be lower than the reference voltage. The reference voltage can be set according to actual needs. Specifically, if the threshold is 300Vac, then, after the 220Vac AC power supply is connected to the power supply circuit 100 after rectification, the ripple voltage on the filter module 20 is small, and the sampling voltage output by the sampling module 30 will be lower than the reference voltage. The comparison module 40 will output a first control signal to the switch module 50, and the switch module 50 will turn on the connection between the output end of the buck module 10 and the load 300, so that the subsequent circuit is powered and starts working; if the 380Vac AC power supply is connected to the rectifier module, the ripple voltage on the filter module 20 is large, and the sampling voltage output by the sampling module 30 will be higher than the reference voltage. The comparison module 40 will output a second control signal to the switch module 50, and the switch module 50 will disconnect the connection between the output end of the buck module 10 and the load 300, ensuring that the subsequent circuit cannot be powered, protecting the subsequent circuit from being damaged by high voltage, thereby improving the safety of circuit operation.

[0027] That is, in the power supply circuit 100 provided in this embodiment, the ripple voltage of the filter module 20 can be detected to determine whether the voltage range of the input AC power supply is within the normal range. If so, the switch module 50 is turned on so that the subsequent circuit is powered. If not, the switch module 50 is turned off to ensure that the subsequent circuit is not damaged, thereby improving the safety of the circuit operation.

[0028] In some of these examples, see Figure 2 The power supply circuit 100 also includes a rectifier module 60; a first end of the rectifier module 60 is used to connect to the input power supply 200, and a second end of the rectifier module 60 is respectively connected to a first end of the filter module 20, a first end of the sampling module 30 and an input end of the buck module 10.

[0029] Specifically, Figure 2 As shown, the rectifier module 60 can be connected to the AC power supply through the live wire L and the neutral wire N. The rectifier module 60 may include a rectifier diode, and the rectifier module 60 can be used to convert the AC power supply into a DC power supply. Its specific circuit structure can refer to the prior art. In this power supply circuit, the input power supply 200 is an AC power supply, and the rectifier module 60 can rectify the AC power supply and output it to the subsequent circuit to ensure the normal operation of the circuit.

[0030] In some of these examples, see Figure 2 , the switch module 50 further includes a first switch unit 51 and a second switch unit 52. The first end of the first switch unit 51 is connected to the output end of the comparison module 40, the second end of the first switch unit 51 is connected to the control end of the second switch unit 52, the first end of the second switch unit 52 is connected to the output end of the buck module 10, and the second end of the second switch unit 52 is used to connect the load 300. The first switch unit 51 is used to turn on or off based on the control signal; the second switch unit 52 is used to disconnect the connection between the output end of the buck module 10 and the load 300 when the first switch unit 51 is turned on, and to establish the connection between the output end of the buck module 10 and the load 300 when the first switch unit 51 is turned off.

[0031] Specifically, the first switch unit 51 can be turned off based on the second control signal, and the second switch unit 52 establishes a connection between the output end of the buck module 10 and the load 300 when the first switch unit 51 is in the turned-off state, so that the load 300 is powered. The first switch unit 51 can also be turned on based on the first control signal, and the second switch unit 52 disconnects the connection between the output end of the buck module 10 and the load 300 when the first switch unit 51 is in the turned-on state, and stops powering the load 300.

[0032] In this embodiment, by providing two switch units, the switch module 50 can establish or disconnect the connection between the output end of the buck module 10 and the load 300 based on the control signal, thereby ensuring the reliability of the circuit operation.

[0033] Specifically, in some of the embodiments, please continue to refer to Figure 2 The first switch unit 51 includes a switch tube Q1 and a resistor R6. The control end of the switch tube Q1 is connected to the output end of the comparison module 40, the first end of the switch tube Q1 is respectively connected to the first end of the resistor R6 and the control end of the second switch unit 52, the second end of the switch tube Q1 is grounded GND, and the second end of the resistor R6 is connected to the first power supply Vcc.

[0034] The first power supply Vcc can be a power supply provided by the output end of the step-down module 10, such as the second end of the resistor R6 can be directly connected to the output end of the step-down module 10. Among them, the switch tube Q1 can be an NPN transistor, the control end of the switch tube Q1 is the base of the NPN transistor, the first end of the switch tube Q1 is the collector of the NPN transistor, the second end of the switch tube Q1 is the emitter of the NPN transistor, the first control signal is a low level, and the second control signal is a high level. If the comparison module 40 outputs a low level, the switch tube Q1 will be in an off state, and the first power supply Vcc will output a high level to the second switch unit 52. If the comparison module 40 outputs a high level, the switch tube Q1 will be in an on state, and the first switch unit 51 will output a low level to the second switch unit 52.

[0035] It can be seen that in this embodiment, by setting the switch tube Q1, the first switch unit 51 can be turned on or off based on the control signal.

[0036] In some of these embodiments, please continue to see Figure 2 The second switch unit 52 includes a switch tube Q3 and a relay K1. The control end of the switch tube Q3 is connected to the second end of the first switch unit 51, the first end of the switch tube Q3 is connected to the first end of the relay K1, the second end of the switch tube Q3 is grounded GND, the second end of the relay K1 is connected to the first power supply Vcc, the third end of the relay K1 is connected to the output end of the step-down module 10, and the fourth end of the relay K1 is used to connect the load 300.

[0037] The first power source Vcc may be a power source provided by the output end of the step-down module 10, such as the second end of the relay K1 may be directly connected to the output end of the step-down module 10. Specifically, the switch tube Q3 may be an NPN transistor, the control end of the switch tube Q3 is the base of the NPN transistor, the first end of the switch tube Q3 is the collector of the NPN transistor, and the second end of the switch tube Q3 is the emitter of the NPN transistor. In the power supply circuit 100, if the first switch unit 51 is in the off state, the first switch unit 51 outputs a high level, then the switch tube Q3 will be turned on, the connection between the first power supply Vcc, the relay K1, the switch tube Q3 and the ground GND is turned on, the relay K1 is powered, the connection between the third end of the relay K1 and the fourth end of the relay K1 is turned on, and the load 300 is powered. If the first switch unit 51 is in the on state, the first switch unit 51 outputs a low level, then the switch tube Q3 will be turned off, the connection between the first power supply Vcc, the relay K1, the switch tube Q3 and the ground GND is disconnected, the relay K1 disconnects the connection between the third end of the relay K1 and the fourth end of the relay K1, and the load 300 cannot be powered.

[0038] It can be seen that in this embodiment, through the above configuration, the second switch unit 52 can be turned on or off based on the on state of the first switch unit 51 .

[0039] In some of these examples, see Figure 2 The filtering module 20 includes a capacitor C1; a first end of the capacitor C1 is respectively connected to the input power supply 200, the input end of the step-down module 10 and the first end of the sampling module 30, and a second end of the capacitor C1 is respectively connected to the second end of the sampling module 30 and the ground GND.

[0040] Specifically, the first end of the capacitor C1 can be respectively connected to the output end of the rectifier module 60, the input end of the buck module 10 and the first end of the sampling module 30. The capacitance of the capacitor C1 is relatively small, which can be 0.3-1uF. In this way, the ripple voltage generated at both ends of the capacitor C1 is relatively large, which can be approximately 1.414 times the voltage of the input power supply. The sampling module 30 can sample the ripple voltage for subsequent comparison.

[0041] In some of these examples, see Figure 2The sampling module 30 includes a resistor R1, a resistor R2, a resistor R3, a resistor R4 and an operational amplifier U1. The first end of the resistor R2 is connected to the first end of the filter module 20, the second end of the resistor R2 is respectively connected to the first end of the resistor R4 and the first input end of the operational amplifier U1, the first end of the resistor R1 is connected to the second end of the filter module 20, the second end of the resistor R1 is respectively connected to the first end of the resistor R3 and the second input end of the operational amplifier U1, the second end of the resistor R3 is grounded GND, and the output end of the operational amplifier U1 is respectively connected to the first input end of the comparison module 40 and the second end of the resistor R4.

[0042] Specifically, the first end of the resistor R2 is connected to the first end of the capacitor C1, the first end of the resistor R1 is connected to the second end of the capacitor C1, the resistance value of the resistor R1 is equal to the resistance value of the resistor R2, the resistance value of the resistor R3 is equal to the resistance value of the resistor R4, then, the voltage output by the operational amplifier U1 is Uo=1.414*Ui*R4 / R2, wherein Ui is the voltage of the input AC power supply, R4 is the resistance value of the resistor R4, and R2 is the resistance value of the resistor R2. In this way, the size of the sampling voltage can be obtained by calculation. Then, after determining the threshold, the voltage size of the reference voltage can be determined by calculating the above formula.

[0043] In this embodiment, by using resistors and operational amplifiers, the accuracy of voltage sampling can be improved, which helps to ensure the accuracy and stability of the sampled voltage.

[0044] In some of these examples, see Figure 2 The comparison module 40 includes a comparator U2, a diode D3 and a resistor R5. The first input terminal of the comparator U2 is respectively connected to the third terminal of the sampling module 30 and the cathode of the diode D3, the second input terminal of the comparator U2 is used to connect the reference voltage, the output terminal of the comparator U2 is respectively connected to the first terminal of the resistor R5 and the anode of the diode D3, and the second terminal of the resistor R5 is connected to the control terminal of the switch module 50.

[0045] Specifically, the first input terminal of the comparator U2 is connected to the output terminal of the operational amplifier U1. In the comparison module 40, if the output voltage of the operational amplifier U1 is less than the reference voltage, the comparator U2 will output a low level. If the output voltage of the operational amplifier U1 is greater than the reference voltage, the comparator U1 will output a high level.

[0046] In this embodiment, the comparator U2 can be used to compare the sampled voltage with the reference voltage and output a corresponding control signal.

[0047] In some of these examples, see Figure 2The step-down module 10 includes a switch tube Q2, a diode D1, a diode D2, an inductor L1 and a capacitor C2. The first end of the switch tube Q2 is connected to the input power supply 200, the second end of the switch tube Q2 is respectively connected to the first end of the inductor L1 and the cathode of the diode D1, the anode of the diode D1 is grounded GND, the second end of the inductor L1 is connected to the anode of the diode D2, the cathode of the diode D2 is respectively connected to the first end of the switch module 50 and the first end of the capacitor C2, and the second end of the capacitor C2 is grounded GND.

[0048] In the step-down module 10, the DC power supply can be stepped down to provide a suitable power supply voltage for the load 300. In this embodiment, by using a switch tube, a diode, an inductor and a capacitor, the step-down module 10 can achieve efficient voltage conversion, and when working at a higher frequency, it can reduce energy loss and improve overall efficiency. In addition, the use of the inductor L1 and the capacitor C2 can smooth the output voltage, reduce noise and fluctuations, and thus provide a more stable output voltage.

[0049] Combine the following Figure 2 The illustrated embodiment describes in detail the specific working process of the power supply circuit provided by the utility model.

[0050] exist Figure 2 In the power supply circuit shown, the live wire L and the neutral wire N are used to connect an AC power source. The AC power source is rectified by the rectifier module 60, filtered by the capacitor C1, and then stepped down by the step-down module 10 to obtain a supply voltage Vcc. Since the capacitance of the filter capacitor C1 (the capacitance is usually 0.3-1uF) is small, the ripple voltage of the capacitor C1 is large, and the ripple voltage can be approximately 1.414 times the input voltage. After the ripple voltage is sampled by the sampling module 30, the sampling voltage will be output to the comparator U2. If the sampling voltage is less than the reference voltage VREF at this time, the comparator U2 will output a low level, the transistor Q1 is in the cut-off state, the transistor Q3 is in the on state, the relay KJ is energized, the connection between the power supply voltage Vcc and the load 300 is connected, and the load 300 is normally powered; if the sampling voltage is greater than the reference voltage VREF at this time, the comparator U2 outputs a high level, the transistor Q1 is in the saturation state, the transistor Q3 is in the cut-off state, the relay KJ is not energized, the connection between the power supply voltage Vcc and the load 300 is disconnected, and the load 300 cannot be powered.

[0051] It can be seen that in the power supply circuit provided in this embodiment, after setting the reference voltage, the ripple voltage of the filter module 20 can be detected to determine whether the voltage range of the input AC power supply is within the normal range. If so, the switch module 50 is turned on to enable the subsequent circuit to be powered. If not, the switch module 50 is turned off to ensure that the subsequent circuit is not damaged, thereby improving the safety of the circuit operation.

[0052] In a second aspect, the embodiment of the utility model further provides a laser welding device, which includes: a laser, a chiller, and a power supply circuit 100 as in any one of the first aspects. The output end of the power supply circuit 100 is connected to the laser and the chiller respectively.

[0053] In this embodiment, the power supply circuit 100 has the same structure and function as the power supply circuit 100 as described in any one of the first aspects, which will not be repeated here. Laser welding equipment is a device that uses the laser emitted by a laser as an energy source to melt metal powder or wire layer by layer and deposit it on the surface of a workpiece. The laser is a device for emitting lasers, and the chiller is a device for cooling the laser welding equipment. The specific structures of the two can refer to the prior art. In this embodiment, by using the power supply circuit, the ripple voltage of the filter module can be detected to determine whether the voltage range of the input AC power supply is within the normal range. If so, the switch module is turned on to power the subsequent circuits such as the laser and the chiller. If not, the switch module is turned off to ensure that the subsequent circuits are not damaged and improve the safety of the circuit operation.

[0054] It should be noted that the device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Under the idea of ​​the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A power supply circuit, characterized in that: include: Buck module, filter module, sampling module, comparison module and switch module; The first end of the filtering module, the first end of the sampling module and the input end of the buck module are all used to connect to the input power supply, the output end of the buck module is connected to the first end of the switch module, the second end of the switch module is used to connect to the load, the second end of the filtering module is respectively connected to the second end of the sampling module and the ground, the third end of the sampling module is connected to the first input end of the comparison module, the second input end of the comparison module is used to connect to the reference voltage, and the output end of the comparison module is the control end of the switch module; Wherein, the filtering module is used to filter the input power supply to generate a ripple voltage; The step-down module is used to step down the input power supply; The sampling module is used for outputting a sampling voltage to the comparison module based on the ripple voltage; The comparison module is used for outputting a control signal to the switch module based on the sampled voltage and the reference voltage; The switch module is used to establish or disconnect the connection between the output end of the buck module and the load based on the control signal.

2. The power supply circuit according to claim 1, characterized in that: The switch module further includes a first switch unit and a second switch unit; The first end of the first switch unit is connected to the output end of the comparison module, the second end of the first switch unit is connected to the control end of the second switch unit, the first end of the second switch unit is connected to the output end of the step-down module, and the second end of the second switch unit is used to connect the load; The first switch unit is used to be turned on or off based on the control signal; The second switch unit is used to disconnect the output end of the buck module and the load when the first switch unit is turned on, and to establish the connection between the output end of the buck module and the load when the first switch unit is turned off.

3. The power supply circuit according to claim 2, characterized in that: The first switch unit includes a switch tube Q1 and a resistor R6; The control end of the switch tube Q1 is connected to the output end of the comparison module, the first end of the switch tube Q1 is respectively connected to the first end of the resistor R6 and the control end of the second switch unit, the second end of the switch tube Q1 is grounded, and the second end of the resistor R6 is connected to the first power supply.

4. The power supply circuit according to claim 2, characterized in that: The second switch unit includes a switch tube Q3 and a relay K1; The control end of the switch tube Q3 is connected to the second end of the first switch unit, the first end of the switch tube Q3 is connected to the first end of the relay K1, the second end of the switch tube Q3 is grounded, the second end of the relay K1 is connected to the first power supply, the third end of the relay K1 is connected to the output end of the buck module, and the fourth end of the relay K1 is used to connect the load.

5. The power supply circuit according to any one of claims 1 to 4, characterized in that: The filtering module includes a capacitor C1; The first end of the capacitor C1 is respectively connected to the input power supply, the input end of the buck module and the first end of the sampling module, and the second end of the capacitor C1 is respectively connected to the second end of the sampling module and the ground.

6. The power supply circuit according to any one of claims 1 to 4, characterized in that: The sampling module includes a resistor R1, a resistor R2, a resistor R3, a resistor R4 and an operational amplifier U1; The first end of the resistor R2 is connected to the first end of the filtering module, the second end of the resistor R2 is respectively connected to the first end of the resistor R4 and the first input end of the operational amplifier U1, the first end of the resistor R1 is connected to the second end of the filtering module, the second end of the resistor R1 is respectively connected to the first end of the resistor R3 and the second input end of the operational amplifier U1, the second end of the resistor R3 is grounded, and the output end of the operational amplifier U1 is respectively connected to the first input end of the comparison module and the second end of the resistor R4.

7. The power supply circuit according to any one of claims 1 to 4, characterized in that: The comparison module includes a comparator U2, a diode D3 and a resistor R5; The first input end of the comparator U2 is respectively connected to the third end of the sampling module and the cathode of the diode D3, the second input end of the comparator U2 is used to connect the reference voltage, the output end of the comparator U2 is respectively connected to the first end of the resistor R5 and the anode of the diode D3, and the second end of the resistor R5 is connected to the control end of the switch module.

8. The power supply circuit according to any one of claims 1 to 4, characterized in that: The step-down module includes a switch tube Q2, a diode D1, a diode D2, an inductor L1 and a capacitor C2; The first end of the switch tube Q2 is connected to the input power supply, the second end of the switch tube Q2 is respectively connected to the first end of the inductor L1 and the cathode of the diode D1, the anode of the diode D1 is grounded, the second end of the inductor L1 is connected to the anode of the diode D2, the cathode of the diode D2 is respectively connected to the first end of the switch module and the first end of the capacitor C2, and the second end of the capacitor C2 is grounded.

9. The power supply circuit according to any one of claims 1 to 4, characterized in that: The power supply circuit also includes a rectifier module; The first end of the rectifier module is used to connect to the input power supply, and the second end of the rectifier module is respectively connected to the first end of the filter module, the first end of the sampling module and the input end of the buck module.

10. A laser welding device, characterized in that: include: A laser, a water chiller, and a power supply circuit as claimed in any one of claims 1 to 9; The output end of the power supply circuit is connected to the laser and the chiller respectively.

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