High-voltage rectifying device applied to ultraviolet curing equipment

Abstract

The utility model relates to the technical field of industrial semiconductors, and discloses a high-voltage rectifying device applied to ultraviolet curing equipment, which is characterized in that four commutator circuits formed by connecting N ultrafast recovery diodes in series are arranged to improve the overall withstand voltage level of a rectifier bridge, and according to actual application requirements, the voltage of the rectifier bridge can be effectively reduced, and the service life of the rectifier bridge can be prolonged. The number of ultrafast recovery diodes connected in series in the commutator circuit can be adjusted to meet the requirements of high voltage resistance and load power supply, the whole circuit is simple and easy to implement, the commutator circuit is formed by connecting a plurality of ultrafast recovery diodes in series, and the mode that a high-voltage rectifier bridge is integrated on an internal circuit board of existing ultraviolet curing equipment is replaced. Alternating-current high voltage is rectified into direct-current high voltage to serve as high-voltage electric field acceleration voltage to supply power to an equipment magnetron; therefore, the space utilization rate of the equipment circuit board is improved, the cost is reduced, the voltage endurance capability of the circuit is improved, and mass production of ultraviolet curing equipment is facilitated.

Description

Technical Field

[0001] This utility model relates to the field of industrial semiconductor technology, and in particular to a high-voltage rectifier device used in ultraviolet curing equipment. Background Technology

[0002] Ultraviolet (UV) curing equipment has wide applications in modern industry. It mainly consists of two key parts: a lamp head (lamp box) for generating UV light and a controller for controlling the lamp head. The lamp head plays a crucial role in the equipment's operation. It uses an internal magnetron to generate high-power radio frequency microwave energy to power the UV lamp, causing it to emit UV light and thus achieving the curing process for specific materials. This working principle is somewhat similar to that of a household appliance like a microwave oven, both utilizing microwave energy to achieve specific functions.

[0003] A magnetron is an electrovacuum device used to generate microwave energy. It mainly consists of a sealed vacuum tube containing a cylindrical central cathode (electron source) and a cylindrical anode. Electrons interact with a high-frequency electromagnetic field under the influence of mutually perpendicular constant magnetic and electric fields, gaining energy from the constant electric field and converting it into microwave energy, thus generating microwave energy. The anode of the magnetron not only collects electrons but also plays a decisive role in the oscillation frequency of the high-frequency electromagnetic field. The anode is made of a highly conductive metal and has multiple resonant cavities. Each small resonant cavity is equivalent to a parallel LC resonant circuit, forming a complex resonant system. During operation, the magnetron requires a control box to provide two voltages: a low-voltage AC filament voltage and a high-voltage DC electric field accelerating voltage. The AC filament voltage can be directly converted from mains power to low-voltage filament voltage using a transformer. However, the other high-voltage DC voltage, besides using a high-power transformer, must also be rectified by a high-voltage rectifier to convert the AC high voltage to DC high voltage.

[0004] In existing technologies, a high-voltage AC circuit is rectified into a high-voltage DC circuit by integrating a high-voltage rectifier bridge into the internal circuit board of the UV curing equipment, which then serves as the accelerating voltage for the high-voltage electric field. However, integrating a high-voltage rectifier bridge has drawbacks, including large circuit board space requirements and high costs, which hinders the mass production of UV curing equipment, and also results in low circuit voltage withstand capability. Utility Model Content

[0005] Therefore, this utility model patent aims to provide a high-voltage rectifier device for ultraviolet curing equipment. It uses only a number of ultra-fast recovery diodes connected in series to form a rectifier sub-circuit, replacing the existing method of integrating a high-voltage rectifier bridge on the internal circuit board of ultraviolet curing equipment. This realizes the rectification of AC high voltage into DC high voltage, thereby improving the space utilization of the circuit board, reducing costs, and improving the circuit's withstand voltage capability by connecting a number of ultra-fast recovery diodes in series, which is beneficial to the mass production of ultraviolet curing equipment.

[0006] This utility model patent provides a high-voltage rectifier device for use in ultraviolet curing equipment. The device includes an AC power supply, a high-power transformer (T), and a magnetron. The output terminal of the AC power supply is connected to the input terminal of the high-power transformer (T). The device is characterized by comprising:

[0007] The circuit comprises a first rectifier circuit (100), a second rectifier circuit (200), a third rectifier circuit (300), a fourth rectifier circuit (400), a first AC input terminal (AC1), a second AC input terminal (AC2), a DC positive output terminal (HV+), and a DC negative output terminal (HV-); wherein the first rectifier circuit (100), the second rectifier circuit (200), the third rectifier circuit (300), and the fourth rectifier circuit (400) are composed of N ultra-fast recovery diodes connected in series, where N≥5; the high-potential output terminal (T) of the high-power transformer (T) out-high The first terminal of the first AC input terminal (AC1) is connected to the first end, the second terminal of the first AC input terminal (AC1) is connected to the input terminal of the first rectifier circuit (100), and the output terminal of the first rectifier circuit (100) is connected to the first intermediate diode (D). 100 The anode of the first intermediate diode (D) 100 The cathode of the high-power transformer (T) is connected to the input terminal of the second rectifier circuit (200), and the output terminal of the second rectifier circuit (200) is connected to the first terminal of the DC positive output terminal (HV+); the low-potential output terminal (T) of the high-power transformer (T) is connected to the first terminal of the DC positive output terminal (HV+). out-low The first terminal of the second AC input terminal (AC2) is connected to the second terminal of the third rectifier circuit (300), and the second terminal of the second AC input terminal (AC2) is connected to the input terminal of the third rectifier circuit (300). The output terminal of the third rectifier circuit (300) is connected to the second intermediate diode (D). 200 The anode of the second intermediate diode (D) 200 The cathode of the fourth rectifier circuit (400) is connected to the input terminal of the second rectifier circuit (200), and the output terminal of the fourth rectifier circuit (400) is connected to the third intermediate diode (D). 300 ) and the fourth intermediate diode (D 400 The anode connection of the third intermediate diode (D) 300 The cathode of the fourth intermediate diode (D) is connected to the input terminal of the third rectifier circuit (300), and the cathode of the fourth intermediate diode (D) is connected to the input terminal of the third rectifier circuit (300). 400The cathode of the fourth rectifier circuit (400) is connected to the input terminal of the first rectifier circuit (100), and the input terminal of the fourth rectifier circuit (400) is connected to the first terminal of the DC negative output terminal (HV-). The second terminals of the DC positive output terminal (HV+) and the DC negative output terminal (HV-) are connected to the magnetron to provide a high voltage DC voltage to the magnetron.

[0008] This utility model patent improves the overall voltage withstand rating of the rectifier bridge by establishing four rectifier circuits composed of N ultra-fast recovery diodes connected in series. Furthermore, the number of ultra-fast recovery diodes connected in series in the rectifier circuits can be adjusted according to actual application requirements to meet high voltage withstand and load power supply needs. The circuit is simple and easy to implement, requiring only a few ultra-fast recovery diodes connected in series to form the rectifier circuit. This replaces the existing method of integrating a high-voltage rectifier bridge on the internal circuit board of UV curing equipment, realizing the rectification of AC high voltage into DC high voltage. This improves the space utilization of the equipment's circuit board, reduces costs, and enhances the circuit's voltage withstand capability, which is beneficial for the mass production of UV curing equipment. Attached Figure Description

[0009] Figure 1 A schematic diagram of the structure of an ultraviolet curing device provided in an embodiment of this utility model;

[0010] Figure 2 A schematic diagram of a high-voltage rectifier device for use in ultraviolet curing equipment, provided as an embodiment of this utility model;

[0011] Figure 3 (a) A circuit diagram of the first rectifier circuit provided in an embodiment of the present invention;

[0012] Figure 3 (b) A circuit diagram of the second rectifier circuit provided in an embodiment of the present invention;

[0013] Figure 3 (c) A circuit diagram of the third rectifier circuit provided in an embodiment of the present invention;

[0014] Figure 3 (d) A circuit diagram of the fourth rectifier circuit provided in an embodiment of the present invention;

[0015] Figure 4 A circuit diagram of the fourth rectifier circuit provided in an embodiment of this utility model;

[0016] Figure 5 The circuit diagram of the overvoltage protection circuit provided in the embodiment of this utility model;

[0017] Figure 6 A circuit diagram of the voltage sampling circuit provided in this embodiment of the utility model;

[0018] Figure 7 A circuit diagram of another ultraviolet curing device provided in this embodiment of the present invention;

[0019] In the diagram: 100, First rectifier circuit; 200, Second rectifier circuit; 300, Third rectifier circuit; 400, Fourth rectifier circuit; 500, Overvoltage protection circuit; 600, Voltage sampling circuit; 700, Current limiting protection circuit; T, High-power transformer; AC, AC power supply; DC, High-voltage DC power supply; AC1, First AC input terminal; AC2, Second AC input terminal; HV+, DC positive output terminal; HV-, DC negative output terminal; D1, First ultra-fast recovery diode; D2, Second ultra-fast recovery diode; D3, Third ultra-fast recovery diode; D4, Fourth ultra-fast recovery diode; D5, Fifth ultra-fast recovery diode; D6, Sixth ultra-fast recovery diode; D7, Seventh ultra-fast recovery diode. Diodes; D8, Eighth Ultrafast Recovery Diode; D9, Ninth Ultrafast Recovery Diode; D10, Tenth Ultrafast Recovery Diode; D11, Eleventh Ultrafast Recovery Diode; D12, Twelfth Ultrafast Recovery Diode; D13, Thirteenth Ultrafast Recovery Diode; D14, Fourteenth Ultrafast Recovery Diode; D15, Fifteenth Ultrafast Recovery Diode; D16, Sixteenth Ultrafast Recovery Diode; D17, Seventeenth Ultrafast Recovery Diode; D18, Eighteenth Ultrafast Recovery Diode; D19, Nineteenth Ultrafast Recovery Diode; D20, Twentieth Ultrafast Recovery Diode; D21, Twenty-first Ultrafast Recovery Diode; D22, Twenty-second Ultrafast Recovery Diode; D23, Twenty-third Ultrafast Recovery Diode; D24, Twenty-fourth Ultrafast Recovery Diode Ultrafast recovery diodes; D25, 25th ultrafast recovery diode; D26, 26th ultrafast recovery diode; D27, 27th ultrafast recovery diode; D28, 28th ultrafast recovery diode; D29, 29th ultrafast recovery diode; D30, 30th ultrafast recovery diode; D31, 31st ultrafast recovery diode; D32, 32nd ultrafast recovery diode; D33, 33rd ultrafast recovery diode; D34, 34th ultrafast recovery diode; D35, 35th ultrafast recovery diode; D36, 36th ultrafast recovery diode; D37, 37th ultrafast recovery diode; D38, 38th ultrafast recovery diode; D39, 39th ultrafast recovery diode; D40 D41, D42, D43, D44, D45, D46, D47, D48, D49, D50, D51, D52, D53, D54, D55, D55; D55, D56, D57, D48, D49, D50, D51, D52, D53, D54, D55, D55; D55, D56, D47, D48, D49, D50, D50, D51, D52, D53, D54, D55, D55; D55, D56, D47, D48, D49, D55, D56, D45, D46, D47, D48, D49, D55, D56, D5 ...D56, 56th ultrafast recovery diode; D57, 57th ultrafast recovery diode; D58, 58th ultrafast recovery diode; D59, 59th ultrafast recovery diode; D60, 60th ultrafast recovery diode; D61, 61st ultrafast recovery diode; D62, 62nd ultrafast recovery diode; D63, 63rd ultrafast recovery diode; D64, 64th ultrafast recovery diode; VR1, first varistor; VR2, second varistor; VR3, third varistor; VR4, fourth varistor; VR5, fifth varistor; VR6, sixth varistor; CN, connector; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; T; out-high The high-potential output terminal of the high-power transformer (T); T out-low The low-potential output terminal of a high-power transformer (T); D 100 First intermediate diode; D 200 Second intermediate diode; D 300 Third intermediate diode; D 400 Fourth intermediate diode; 100 in The input terminal of the first rectifier circuit 100; 100 out The output terminal of the first rectifier circuit 100; 200 in The input terminal of the second rectifier circuit 200; 200 out The output terminal of the second rectifier circuit 200; 300 in The input terminal of the third rectifier circuit 300; 300 out The output terminal of the third rectifier circuit 300; 400 in The input terminal of the fourth rectifier circuit 400; 400 out The output terminal of the fourth rectifier circuit 400; Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] This utility model embodiment provides a high-voltage rectifier device for use in ultraviolet curing equipment, such as... Figure 1As shown, the ultraviolet curing equipment includes an AC power supply, a high-power transformer T, a magnetron, and a high-voltage rectifier. The output terminal of the AC power supply is connected to the input terminal of the high-power transformer T. For example, 240V AC mains power can be boosted to approximately 7000V on the secondary side of the high-power transformer T, while maintaining the AC mains cycle. Then, the high-voltage rectifier converts the 7000V AC voltage into DC voltage, which serves as the accelerating voltage for the high-voltage electric field, i.e., as the high-voltage DC power supply for the magnetron. This powers the magnetron, enabling it to generate high-power radio frequency microwave energy to power the ultraviolet lamp, causing the lamp to emit ultraviolet light, thereby achieving the curing treatment of specific materials. This is an explanation of the application scenario of the high-voltage rectifier described in this embodiment of the invention.

[0022] like Figure 2 As shown, the high-voltage rectifier includes: a first rectifier circuit (100), a second rectifier circuit (200), a third rectifier circuit (300), a fourth rectifier circuit (400), a first AC input terminal (AC1), a second AC input terminal (AC2), a DC positive output terminal (HV+), and a DC negative output terminal (HV-); wherein the first rectifier circuit (100), the second rectifier circuit (200), the third rectifier circuit (300), and the fourth rectifier circuit (400) are composed of N ultra-fast recovery diodes connected in series, where N≥5; the high-potential output terminal (T) of the high-power transformer (T) out-high The first terminal of the first AC input terminal (AC1) is connected to the first end, the second terminal of the first AC input terminal (AC1) is connected to the input terminal of the first rectifier circuit (100), and the output terminal of the first rectifier circuit (100) is connected to the first intermediate diode (D). 100 The anode of the first intermediate diode (D) 100 The cathode of the high-power transformer (T) is connected to the input terminal of the second rectifier circuit (200), and the output terminal of the second rectifier circuit (200) is connected to the first terminal of the DC positive output terminal (HV+); the low-potential output terminal (T) of the high-power transformer (T) is connected to the first terminal of the DC positive output terminal (HV+). out-low The first terminal of the second AC input terminal (AC2) is connected to the second terminal of the third rectifier circuit (300), and the second terminal of the second AC input terminal (AC2) is connected to the input terminal of the third rectifier circuit (300). The output terminal of the third rectifier circuit (300) is connected to the second intermediate diode (D). 200 The anode of the second intermediate diode (D) 200 The cathode of the fourth rectifier circuit (400) is connected to the input terminal of the second rectifier circuit (200), and the output terminal of the fourth rectifier circuit (400) is connected to the third intermediate diode (D). 300 ) and the fourth intermediate diode (D400 The anode connection of the third intermediate diode (D) 300 The cathode of the fourth intermediate diode (D) is connected to the input terminal of the third rectifier circuit (300), and the cathode of the fourth intermediate diode (D) is connected to the input terminal of the third rectifier circuit (300). 400 The cathode of the fourth rectifier circuit (400) is connected to the input terminal of the first rectifier circuit (100), and the input terminal of the fourth rectifier circuit (400) is connected to the first terminal of the DC negative output terminal (HV-). The second terminals of the DC positive output terminal (HV+) and the DC negative output terminal (HV-) are connected to the magnetron to provide a high voltage DC voltage to the magnetron.

[0023] This utility model patent improves the overall voltage withstand level of the rectifier bridge by setting up four rectifier circuits composed of N ultra-fast recovery diodes connected in series. Furthermore, the number of ultra-fast recovery diodes connected in series in the rectifier circuits can be adjusted according to actual application requirements to meet the requirements of high voltage resistance and load power supply. For example, when N=16, the first rectifier circuit 100, the second rectifier circuit 200, the third rectifier circuit 300, and the fourth rectifier circuit 400 are composed of 16 ultrafast recovery diodes connected in series. Among them, the ultrafast recovery diodes can be UF5408G diodes, which have a reverse repetitive peak voltage of 1000V. That is, the maximum voltage that the ultrafast recovery diode can withstand when reverse biased is 1000V, ensuring that it will not be damaged by excessive reverse voltage in the circuit. Therefore, the withstand voltage of the rectifier circuit composed of 5 ultrafast recovery diodes connected in series reaches 16kV, which is more than twice the peak voltage output on the secondary side of the high-power transformer T (such as 7000V mentioned above). This not only meets the design requirements of the circuit, but also the rectified current of the ultrafast recovery diodes reaches 3A, which can also meet the needs of the load (magnetron power supply). The withstand voltage is significantly improved compared with the existing technology.

[0024] In summary, the high-voltage rectifier device described in this embodiment of the present invention has a simple and easy-to-implement circuit structure. It only requires multiple ultra-fast recovery diodes connected in series to form a rectifier sub-circuit, which replaces the existing method of integrating a high-voltage rectifier bridge on the internal circuit board of UV curing equipment. This rectifies AC high voltage into DC high voltage, thereby improving the space utilization of the equipment circuit board, reducing costs, and improving the circuit's withstand voltage capability, which is beneficial for the mass production of UV curing equipment.

[0025] In one feasible implementation, N=16; that is, the first rectifier circuit 100, the second rectifier circuit 200, the third rectifier circuit 300 and the fourth rectifier circuit 400 are composed of 16 ultrafast recovery diodes connected in series; wherein, the ultrafast recovery diodes can be diodes of model UF5408G.

[0026] like Figure 3As shown, the first rectifier circuit 100 includes a first ultrafast recovery diode D1, a second ultrafast recovery diode D2, a third ultrafast recovery diode D3, a fourth ultrafast recovery diode D4, a fifth ultrafast recovery diode D5, a sixth ultrafast recovery diode D6, a seventh ultrafast recovery diode D7, an eighth ultrafast recovery diode D8, a ninth ultrafast recovery diode D9, a tenth ultrafast recovery diode D10, an eleventh ultrafast recovery diode D11, a twelfth ultrafast recovery diode D12, a thirteenth ultrafast recovery diode D13, a fourteenth ultrafast recovery diode D14, a fifteenth ultrafast recovery diode D15, and a sixteenth ultrafast recovery diode D16. The cathode of the first ultrafast recovery diode D1 is connected to the anode of the second ultrafast recovery diode D2, and so on. The cathode of the fifteenth ultrafast recovery diode D15 is connected to the anode of the sixteenth ultrafast recovery diode D16. Wherein, the anode of the first ultrafast recovery diode (D1) included in the first rectifier circuit (100) serves as the input terminal of the first rectifier circuit (100), and the cathode of the sixteenth ultrafast recovery diode (D16) included in the first rectifier circuit (100) serves as the output terminal of the first rectifier circuit (100).

[0027] The second rectifier circuit 200 includes a seventeenth ultrafast recovery diode D17, an eighteenth ultrafast recovery diode D18, a nineteenth ultrafast recovery diode D19, a twentieth ultrafast recovery diode D20, a twenty-first ultrafast recovery diode D21, a twenty-second ultrafast recovery diode D22, a twenty-third ultrafast recovery diode D23, a twenty-fourth ultrafast recovery diode D24, a twenty-fifth ultrafast recovery diode D25, a twenty-sixth ultrafast recovery diode D26, a twenty-seventh ultrafast recovery diode D27, a twenty-eighth ultrafast recovery diode D28, a twenty-ninth ultrafast recovery diode D29, a thirtieth ultrafast recovery diode D30, a thirty-first ultrafast recovery diode D31, and a thirty-second ultrafast recovery diode D32. The cathode of the seventeenth ultrafast recovery diode D17 is connected to the anode of the eighteenth ultrafast recovery diode D18, and so on. The cathode of the thirty-first ultrafast recovery diode D31 is connected to the anode of the thirty-second ultrafast recovery diode D32. The anode of the seventeenth ultrafast recovery diode (D17) included in the second rectifier circuit (200) serves as the input terminal of the second rectifier circuit (200), and the cathode of the thirty-second ultrafast recovery diode (D32) included in the second rectifier circuit (200) serves as the output terminal of the second rectifier circuit (200).

[0028] The third rectifier circuit 300 includes a thirty-third ultrafast recovery diode D33, a thirty-fourth ultrafast recovery diode D34, a thirty-fifth ultrafast recovery diode D35, a thirty-sixth ultrafast recovery diode D36, a thirty-seventh ultrafast recovery diode D37, a thirty-eighth ultrafast recovery diode D38, a thirty-ninth ultrafast recovery diode D39, a fortieth ultrafast recovery diode D40, a forty-first ultrafast recovery diode D41, a forty-second ultrafast recovery diode D42, a forty-third ultrafast recovery diode D43, a forty-fourth ultrafast recovery diode D44, a forty-fifth ultrafast recovery diode D45, a forty-sixth ultrafast recovery diode D46, a forty-seventh ultrafast recovery diode D47, and a forty-eighth ultrafast recovery diode D48. The cathode of the thirty-third ultrafast recovery diode D33 is connected to the anode of the thirty-fourth ultrafast recovery diode D34, and so on, with the cathode of the forty-seventh ultrafast recovery diode D47 connected to the anode of the forty-eighth ultrafast recovery diode D48. The anode of the thirty-third ultrafast recovery diode (D33) included in the third rectifier circuit (300) serves as the input terminal of the third rectifier circuit (300), and the cathode of the forty-eighth ultrafast recovery diode (D48) included in the third rectifier circuit (300) serves as the output terminal of the third rectifier circuit (300).

[0029] The fourth rectifier circuit 400 includes a forty-ninth ultrafast recovery diode D49, a fiftieth ultrafast recovery diode D50, a fifty-first ultrafast recovery diode D51, a fifty-second ultrafast recovery diode D52, a fifty-third ultrafast recovery diode D53, a fifty-fourth ultrafast recovery diode D54, a fifty-fifth ultrafast recovery diode D55, a fifty-sixth ultrafast recovery diode D56, a fifty-seventh ultrafast recovery diode D57, a fifty-eighth ultrafast recovery diode D58, a fifty-ninth ultrafast recovery diode D59, a sixtieth ultrafast recovery diode D60, a sixty-first ultrafast recovery diode D61, a sixty-second ultrafast recovery diode D62, a sixty-third ultrafast recovery diode D63, and a sixty-fourth ultrafast recovery diode D64. The cathode of the forty-ninth ultrafast recovery diode D49 is connected to the anode of the fiftieth ultrafast recovery diode D50, and so on. The cathode of the sixty-third ultrafast recovery diode D63 is connected to the anode of the sixty-fourth ultrafast recovery diode D64. The anode of the forty-ninth ultrafast recovery diode (D49) included in the fourth rectifier circuit (400) serves as the input terminal of the fourth rectifier circuit (400), and the cathode of the sixty-fourth ultrafast recovery diode (D64) included in the fourth rectifier circuit (400) serves as the output terminal of the fourth rectifier circuit (400).

[0030] like Figure 4As shown, the device further includes an overvoltage protection circuit (500); wherein the overvoltage protection circuit (500) includes a first varistor VR1, a second varistor VR2, a third varistor VR3, a fourth varistor VR4, a fifth varistor VR5, and a sixth varistor VR6 connected in series; wherein the input terminal of the overvoltage protection circuit (500) is connected to the output terminal of the second rectifier circuit (200), and the output terminal of the overvoltage protection circuit (500) is connected to the input terminal of the fourth rectifier circuit (400); wherein the first terminal of the first varistor (VR1) serves as the input terminal (500) of the overvoltage protection circuit (500). in The second terminal of the first varistor (VR1) is connected to the second varistor (VR2); the first terminal of the sixth varistor (VR6) serves as the output terminal (500) of the overvoltage protection circuit (500). out The second end of the sixth varistor (VR6) is connected to the fifth varistor (VR5).

[0031] The first varistor VR1, the second varistor VR2, the third varistor VR3, the fourth varistor VR4, the fifth varistor VR5, and the sixth varistor VR6 are all Littelfuse V1000LA160BP varistors. This varistor has a peak surge current of 6500A, meaning it can withstand instantaneous surge currents of up to 6500A, exhibiting strong surge resistance and providing effective overvoltage protection for other components in the circuit. Furthermore, this varistor has an energy absorption capacity of up to 360J, capable of absorbing significant energy. When subjected to overvoltage surges, it can convert excess energy into heat and dissipate it, thus protecting other components in the circuit from damage. Additionally, the maximum RMS voltage of this varistor is 1000V (RMS is the effective value). In an AC circuit, its effective voltage withstand value is 1000V, meaning the maximum effective voltage that the overvoltage protection circuit can withstand is 6000V.

[0032] Therefore, when the output voltage of the thirty-second ultrafast recovery diode D32 and the sixty-fourth ultrafast recovery diode D64 exceeds a certain threshold (which can be set to 6000V), the resistance values ​​of the first varistor VR1, the second varistor VR2, the third varistor VR3, the fourth varistor VR4, the fifth varistor VR5, and the sixth varistor VR6 will decrease rapidly. This causes the output current of the thirty-second ultrafast recovery diode D32 and the sixty-fourth ultrafast recovery diode D64 to flow through the overvoltage protection circuit, which serves as a current shunting mechanism and provides overvoltage protection to prevent damage to components in the circuit due to overvoltage.

[0033] In addition, to quickly respond to transient voltage changes and absorb surge energy, thereby protecting the circuit from lightning surges, the device also includes a bidirectional TVS diode. One end of the bidirectional TVS diode is connected to the output terminal of the fourth rectifier circuit (400), and the other end is connected to the DC positive output terminal (HV+). It should be noted that the bidirectional TVS diode in this embodiment is a Littelfuse 5KP24CA transient voltage suppressor diode, whose reverse off-state voltage is typically 24V. This means that under normal operating conditions, the bidirectional TVS diode is in a reverse cutoff state and can withstand a maximum reverse voltage of 24V. Its minimum breakdown voltage is 26.7V, and its maximum breakdown voltage is 29.5V. When the reverse voltage exceeds this range, the bidirectional TVS diode begins to conduct, clamping the excessive voltage to a safe level. Its peak pulse power can reach 5kW, enabling it to absorb a large amount of energy instantaneously, protecting other components in the circuit from damage caused by transient high voltages. The maximum clamping voltage is 38.9V. When a transient voltage occurs, the bidirectional TVS diode will limit the voltage below this value to prevent the downstream circuit from being subjected to excessively high voltage.

[0034] In one feasible implementation, such as Figure 5 As shown, the device also includes a voltage sampling circuit (600).

[0035] The voltage sampling circuit (600) includes a connector CN, a first resistor R1, and a second resistor R2; the first input terminal (600) of the voltage sampling circuit (600) in1 The output terminal of the overvoltage protection circuit (500) is connected to the output terminal of the voltage sampling circuit (600); the second input terminal of the voltage sampling circuit (600) is connected to the output terminal of the overvoltage protection circuit (500). in2 The output terminal of the second rectifier circuit (200) is connected to the output terminal of the voltage sampling circuit (600); the first output terminal of the voltage sampling circuit (600) is connected to the output terminal of the second rectifier circuit (200). out1 ) and second output terminal (600) out2 The first terminal of the DC positive output terminal (HV+) is connected; wherein, the first terminal of the second resistor (R2) serves as the first input terminal (600) of the voltage sampling circuit (600). in1 The second end of the second resistor (R2) is connected to the first end of the first resistor (R1) and the second input end (a2) of the connector (CN), respectively. The second end of the first resistor (R1) serves as the first output end (a2) of the voltage sampling circuit (600). out1 The first input terminal (a1) of the connector (CN) serves as the second input terminal (600) of the voltage sampling circuit (600). in2The first output terminal (b1) and the second output terminal (b2) of the connector (CN) serve as the second output terminal (600) of the voltage sampling circuit (600). out2 The voltage sampling circuit is used to sample the high-voltage DC output voltage. In this embodiment, the second resistor R2 has a resistance of 50MΩ and a withstand voltage of 15kV, the first resistor R1 has a resistance of 20kΩ, and the ratio of the resistance values ​​of the first resistor R1 to the second resistor R2 is 1:2500. Therefore, the sampling voltage of the voltage sampling circuit is 1 / 2500 of the high-voltage DC output voltage. It should be noted that the connector CN in this embodiment has 10 pins with a pin pitch of 2.54 mm.

[0036] In one feasible implementation, the device further includes a sixth resistor; one end of the sixth resistor is connected to the output terminal of the fourth rectifier circuit 400, and the other end is connected to the DC positive output terminal HV+. The sixth resistor is used to collect the high-voltage DC output current, and its resistance is 5R. Therefore, the maximum current flowing through the sixth resistor is 1A, and the maximum current feedback value is 1A * 5R = 1V.

[0037] In one feasible implementation, such as Figure 6 As shown, the device further includes a current limiting protection circuit (700); wherein the current limiting protection circuit (700) includes a third resistor R3, a fourth resistor R4, and a fifth resistor R5 connected in series; the input terminal (700) of the current limiting protection circuit (700) in The output terminal of the second rectifier circuit (200) is connected to the output terminal of the current limiting protection circuit (700). out The first terminal of the DC positive output terminal (HV+) is connected; wherein, the first terminal of the third resistor (R3) serves as the input terminal (700) of the current limiting protection circuit (700). in The first terminal of the fifth resistor (R5) serves as the output terminal of the current limiting protection circuit (700). out The second terminal of the third resistor (R3) is connected to the first terminal of the fourth resistor (R4), and the second terminal of the fifth resistor (R5) is connected to the second terminal of the fourth resistor (R4). The third resistor R3, the fourth resistor R4, and the fifth resistor R5 are protective resistors that limit current to prevent damage to the circuit due to excessive current caused by a short circuit.

[0038] like Figure 7As shown, the aforementioned UV curing equipment also includes a power controller and a main control board. The voltage sampling circuit samples the high-voltage DC output voltage and current, and feeds these samples back to the main control board. The main control board, based on the sampled voltage and current and according to its internal algorithm, controls the conduction angle of the bidirectional thyristor in the power controller to meet the load's output voltage requirements. For example, if only a 3000V DC voltage is needed at the output, the high-voltage DC output voltage and current are sampled and fed back to the main control board. Finally, the conduction angle of the bidirectional thyristor in the power controller is controlled to reduce the output voltage on the secondary side of the high-power transformer T. This makes the equipment's power output a closed-loop control system, capable of adaptively adjusting the high-voltage DC output according to the load's needs.

Claims

1. A high voltage rectifying device applied to an ultraviolet light curing equipment, the equipment comprising an alternating current power supply (AC), a high power transformer (T) and a magnetron, the output end of the alternating current power supply (AC) being connected with the input end of the high power transformer (T), characterized in that, The device comprises: a first rectifier circuit (100), a second rectifier circuit (200), a third rectifier circuit (300), a fourth rectifier circuit (400), a first AC input terminal (AC1), a second AC input terminal (AC2), a DC positive output terminal (HV+) and a DC negative output terminal (HV-); wherein the first rectifier circuit (100), the second rectifier circuit (200), the third rectifier circuit (300) and the fourth rectifier circuit (400) are connected in series by N super-fast recovery diodes, N≥5; The high potential output end (T out-high ) of the large power transformer (T) is connected with the first end of the first AC input terminal (AC1), the second end of the first AC input terminal (AC1) is connected with the input end of the first rectifier sub-circuit (100), the output end of the first rectifier sub-circuit (100) is connected with the anode of the first intermediate diode (D 100 ), the cathode of the first intermediate diode (D 100 ) is connected with the input end of the second rectifier sub-circuit (200), and the output end of the second rectifier sub-circuit (200) is connected with the first end of the DC positive output terminal (HV+). The low potential output end (T out-low ) of the high-power transformer (T) is connected to the first end of the second AC input terminal (AC2), the second end of the second AC input terminal (AC2) is connected to the input end of the third rectifier sub-circuit (300), the output end of the third rectifier sub-circuit (300) is connected to the anode of the second intermediate diode (D 200 ), the cathode of the second intermediate diode (D 200 ) is connected to the input end of the second rectifier sub-circuit (200), the output end of the fourth rectifier sub-circuit (400) is respectively connected to the anodes of the third intermediate diode (D 300 ) and the fourth intermediate diode (D 400 ), the cathode of the third intermediate diode (D 300 ) is connected to the input end of the third rectifier sub-circuit (300), the cathode of the fourth intermediate diode (D 400 ) is connected to the input end of the first rectifier sub-circuit (100), and the input end of the fourth rectifier sub-circuit (400) is connected to the first end of the DC negative output terminal (HV-). the second end of the DC positive output terminal (HV+) and the DC negative output terminal (HV-) is connected to the magnetron, for providing high-voltage DC voltage for the magnetron.

2. The high voltage rectifier device of claim 1, wherein N=16； wherein the anode of the first super-fast recovery diode (D1) contained in the first rectifier circuit (100) is used as the input terminal of the first rectifier circuit (100), and the cathode of the sixteenth super-fast recovery diode (D16) contained in the first rectifier circuit (100) is used as the output terminal of the first rectifier circuit (100); the anode of the seventeenth super-fast recovery diode (D17) contained in the second rectifier circuit (200) is used as the input terminal of the second rectifier circuit (200), and the cathode of the thirty-second super-fast recovery diode (D32) contained in the second rectifier circuit (200) is used as the output terminal of the second rectifier circuit (200); the anode of the thirty-third super-fast recovery diode (D33) contained in the third rectifier circuit (300) is used as the input terminal of the third rectifier circuit (300), and the cathode of the forty-eighth super-fast recovery diode (D48) contained in the third rectifier circuit (300) is used as the output terminal of the third rectifier circuit (300); the anode of the forty-ninth super-fast recovery diode (D49) contained in the fourth rectifier circuit (400) is used as the input terminal of the fourth rectifier circuit (400), and the cathode of the sixty-fourth super-fast recovery diode (D64) contained in the fourth rectifier circuit (400) is used as the output terminal of the fourth rectifier circuit (400).

3. The high voltage rectifier device of claim 2, wherein The device further comprises an overvoltage protection circuit (500); wherein the overvoltage protection circuit comprises first to sixth varistors (VR1-VR6) connected in series; the input terminal of the overvoltage protection circuit (500) is connected to the output terminal of the second rectifier circuit (200), and the output terminal of the overvoltage protection circuit (500) is connected to the input terminal of the fourth rectifier circuit (400). The first end of the first voltage-dependent resistor (VR1) is used as an input end of the overvoltage protection circuit (500), and the second end of the first voltage-dependent resistor (VR1) is connected with the second voltage-dependent resistor (VR2); the first end of the sixth voltage-dependent resistor (VR6) is used as an output end of the overvoltage protection circuit (500), and the second end of the sixth voltage-dependent resistor (VR6) is connected with the fifth voltage-dependent resistor (VR5).

4. The high voltage rectifier device of claim 3, wherein The device further comprises a voltage sampling circuit (600); wherein the voltage sampling circuit (600) comprises a connector (CN), a first resistor (R1) and a second resistor (R2); The first input end (600 in1 ) of the voltage sampling circuit (600) is connected with the output end of the overvoltage protection circuit (500); the second input end (600 in2 ) of the voltage sampling circuit (600) is connected with the output end of the second rectifier circuit (200); the first output end (600 out1 ) and the second output end (600 out2 ) of the voltage sampling circuit (600) are connected with the first end of the direct current positive output terminal (HV+). The first end of the second resistor (R2) is the first input end (600 in1 ) of the voltage sampling circuit (600), the second end of the second resistor (R2) is connected with the first end of the first resistor (R1) and the second input end (a2) of the connector (CN) respectively, the second end of the first resistor (R1) is the first output end (600 out1 ) of the voltage sampling circuit (600); the first input end (a1) of the connector (CN) is the second input end (600 in2 ) of the voltage sampling circuit (600); the first output end (b1) and the second output end (b2) of the connector (CN) are the second output end (600 out2 ) of the voltage sampling circuit (600); wherein the resistance ratio of the first resistor (R1) and the second resistor (R2) is 1:2500.

5. The high voltage rectifier device of claim 4, wherein The device further comprises a current-limiting protection circuit (700); wherein the current-limiting protection circuit (700) comprises a third resistor (R3), a fourth resistor (R4) and a fifth resistor (R5) connected in series; an input end (700 in ) of the current-limiting protection circuit (700) is connected to an output end of the second rectifier circuit (200); an output end (700 out ) of the current-limiting protection circuit (700) is connected to a first end of the DC positive output terminal (HV+); wherein a first end of the third resistor (R3) serves as the input end (700 in ) of the current-limiting protection circuit (700), and a first end of the fifth resistor (R5) serves as the output end (700 out ) of the current-limiting protection circuit (700).

6. The high voltage rectifier device of claim 5, wherein The device further comprises a bidirectional TVS diode, one end of the bidirectional TVS diode is connected with the output end of the fourth rectifier circuit (400), and the other end is connected with the direct current positive output terminal (HV+).

7. The high voltage rectifier device of claim 6, wherein The device further comprises a sixth resistor, one end of the sixth resistor is connected with the output end of the fourth rectifier circuit (400), and the other end is connected with the direct current positive output terminal (HV+). The device further comprises a sixth resistor, one end of the sixth resistor is connected with the output end of the fourth rectifier circuit (400), and the other end is connected with the direct current positive output terminal (HV+).

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