CN114826004A

CN114826004A - Rectifier and power supply device for laser

Info

Publication number: CN114826004A
Application number: CN202111405608.9A
Authority: CN
Inventors: 木内康太
Original assignee: Sumitomo Heavy Industries Ltd
Current assignee: Sumitomo Heavy Industries Ltd
Priority date: 2021-01-18
Filing date: 2021-11-24
Publication date: 2022-07-29
Also published as: TWI806252B; KR20220104630A; JP2022110508A; TW202229894A

Abstract

The invention provides a rectifier capable of detecting a phase failure in a manner different from a conventional manner. A rectifier (100) converts a multiphase alternating voltage into a direct voltage. The multiphase ac voltage is supplied to a plurality of ac input terminals. A bridge circuit (110) rectifies the multiphase AC voltage. The rectifier (100) is provided with a plurality of single-phase input devices (120_1, 120_ 2). Each single-phase input device (120) is capable of operating with a single-phase alternating voltage (Vac) input between a 1 st input terminal (IN1) and a 2 nd input terminal (IN2) as a power supply, and is capable of outputting an error IN response to a cut-off of the single-phase alternating voltage (Vac).

Description

Rectifier and power supply device for laser

The present application claims priority based on japanese patent application No. 2021-005969, applied on 1/18/2021. The entire contents of this Japanese application are incorporated by reference into this specification.

Technical Field

The present invention relates to a rectifier.

Background

Industrial equipment, industrial machinery, air conditioners, refrigerators, and the like (hereinafter, simply referred to as equipment) operate with an ac voltage as a power input. Therefore, the power supply apparatus of the industrial equipment includes: a rectifier for rectifying the AC voltage; a capacitor for smoothing the rectified voltage; and a converter or inverter that converts the dc voltage generated in the capacitor into an appropriate power supply signal or driving signal.

As an abnormality of the ac voltage, a phase loss is known. In the phase loss, the main circuit operates in a single phase, and an increase in current and an increase in ripple occur per 1 phase, which causes heat generation. Therefore, the power supply device is required to have a function of detecting a phase failure.

Patent document 1: japanese laid-open patent publication No. 6-333186

Patent document 2: japanese patent laid-open publication No. 2015-32746

Patent document 3: japanese patent laid-open No. 2006-203958

The conventional phase failure detection circuit is configured by a combination of a plurality of photocouplers, a resistor, and a plurality of diodes, and the number of components is large.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an exemplary object of one embodiment of the present invention is to provide a rectifier capable of detecting a phase loss in a manner different from that of the conventional rectifier.

One embodiment of the present invention relates to a rectifier that rectifies a multiphase alternating voltage. The rectifier is provided with: a plurality of AC input terminals for receiving a multiphase AC voltage; a bridge circuit rectifying a multiphase AC voltage; and a plurality of single-phase input devices, each of which is operable with a single-phase alternating-current voltage input between the 1 st input terminal and the 2 nd input terminal as a power source and is capable of detecting an error in response to a cut-off of the single-phase alternating-current voltage. The 1 st input terminal and the 2 nd input terminal of each of the plurality of single-phase input devices are connected to different 2 pairs of the plurality of ac input terminals.

Any combination of the above-described constituent elements and a mode of replacing the constituent elements or expressions with each other in a method, an apparatus, a system, or the like are also effective as embodiments of the present invention.

Effects of the invention

According to one embodiment of the invention, a phase loss can be detected.

Drawings

Fig. 1 is a block diagram of a rectifier according to an embodiment.

Fig. 2 is a diagram illustrating detection of a phase loss by the rectifier of fig. 1.

Fig. 3 is a diagram showing a rectifier according to example 1.

Fig. 4 is a diagram illustrating an operation of the rectifier of fig. 3.

Fig. 5 is a diagram illustrating the structure of the AC fan and the connection method thereof.

Fig. 6 is a block diagram of a rectifier according to embodiment 2.

Fig. 7 is a diagram illustrating the rectifier of fig. 6 for detecting a phase loss.

Fig. 8 is a diagram showing a laser processing apparatus.

Fig. 9 is a block diagram of the laser apparatus of fig. 8.

In the figure: 100-rectifier, 102-frame, 110-bridge circuit, 112-smoothing capacitor, 114-reactor, 120-single-phase input device, IN 1-input terminal 1, IN 2-

input terminal

2, 120A-AC fan, 122-fan motor, 124-drive circuit, 126-switch, 128-lock detection circuit, 130-controller, 200-laser resonator, 250-power supply device, 300-charging power supply, 400-high frequency power supply, 800-laser device.

Detailed Description

(outline of embodiment)

A summary of certain exemplary embodiments of the present invention is described. This summary is provided as a prelude to the detailed description that will be described later, and is intended to simplify certain concepts of describing one or more embodiments for the purpose of basic understanding of the embodiments, and does not limit the scope of the invention or the disclosure. This summary is not an overall summary of all conceivable embodiments, and does not limit the essential components of the embodiments. For convenience of description, "one embodiment" is sometimes used as a mode of referring to one embodiment (example or modification) or a plurality of embodiments (example or modification) disclosed in the present specification.

The rectifier according to an embodiment rectifies a multiphase ac voltage. The rectifier is provided with: a plurality of AC input terminals for receiving a multiphase AC voltage; a bridge circuit rectifying a multiphase AC voltage; and a plurality of single-phase input devices, each of which is operable with a single-phase alternating-current voltage input between the 1 st input terminal and the 2 nd input terminal as a power source and is capable of detecting an error in response to a cut-off of the single-phase alternating-current voltage. The 1 st input terminal and the 2 nd input terminal of each of the plurality of single-phase input devices are connected to different 2 pairs of the plurality of ac input terminals.

According to this configuration, if a phase loss occurs, the single-phase ac voltage is cut off in at least one of the plurality of single-phase input devices, and thus an abnormality is detected. Therefore, by monitoring the results of the error detection in the plurality of single-phase input apparatuses, it is possible to detect the open-phase abnormality.

In one embodiment, each of the plurality of single-phase input devices may be capable of outputting a signal indicating an error state when it is unable to perform its own function, i.e., when it falls into a malfunction state. At this time, when the single-phase ac voltage is cut off, the single-phase ac voltage falls into a functional failure state, and therefore a signal indicating an error state is output. By monitoring the results of error detection in the plurality of single-phase input apparatuses, it is possible to detect a phase-missing abnormality and a malfunction.

In an embodiment, the rectifier may further have a controller that processes results of error detection in the plurality of single-phase input devices.

In an embodiment, the controller may stop a functional block downstream of the rectifier if an error condition is detected in at least one of the plurality of single phase input devices. Thereby, the interlock function can be realized.

In one embodiment, the single phase input device may be an AC fan. The AC fan outputs an error when the motor is locked. When the single-phase ac voltage is cut off, the motor is stopped (this is a failure state), and the motor is detected as being locked. That is, the interruption of the single-phase ac voltage can be indirectly detected as the locking of the motor caused by the interruption. In many apparatuses, an AC fan is provided for cooling a power supply circuit. By using this AC fan for the phase loss detection, an increase in cost can be suppressed.

In one embodiment, a single phase input device may include: 1 st error detection terminal; 2 nd error detection terminal; and a switch which is provided between the 1 st error detection terminal and the 2 nd error detection terminal and is turned on during the input of the single-phase alternating-current voltage. The plurality of single-phase input devices may be connected in series with each other in a switch. In the normal state, all of the plurality of switches are turned on to turn on the series connection, and on the other hand, if a phase loss occurs, the switches are turned off in at least one of the plurality of single-phase input devices, and therefore the series connection is turned off. Therefore, the phase loss can be detected based on the electrical state of the series connection of the plurality of switches.

In one embodiment, the multiphase ac voltage is 3 phases including R phase, S phase, and T phase, and the plurality of single-phase input devices may include: 1 st single-phase input device, which applies voltage between R phase and S phase to single-phase input; and 2 nd single-phase input equipment for applying voltage between S phase and T phase to the single-phase input of the 2 nd single-phase input equipment. For convenience only, the R phase, S phase, and T phase are distinguished.

In one embodiment, the 1 st single phase input device may be an AC fan for air intake and the 2 nd single phase input device may be an AC fan for air exhaust.

In an embodiment, the plurality of single phase input devices may further include a 3 rd single phase input device to which a voltage between the T phase and the R phase is applied to a single phase input thereof. By using 3 single-phase input devices, it is possible to determine which of the R-phase, S-phase, and T-phase an abnormality has occurred.

(embodiment mode)

Hereinafter, preferred embodiments will be described with reference to the drawings. The same or equivalent constituent elements, components and processes shown in the respective drawings are denoted by the same reference numerals, and overlapping descriptions are appropriately omitted. The embodiments are not intended to limit the invention, but merely to exemplify the invention, and all the features or combinations thereof described in the embodiments are not necessarily essential to the invention.

Fig. 1 is a block diagram of a rectifier 100 according to an embodiment. The rectifier 100 rectifies a multiphase ac voltage (three phases in the present embodiment).

The rectifier 100 includes an ac input terminal R, S, T, a bridge circuit 110, a smoothing capacitor 112, a plurality of single-phase input devices 120_1 and 120_2, and a controller 130.

The three-phase ac voltage is input to the ac input terminal R, S, T. The bridge circuit 110 and the smoothing capacitor 112 constitute the main circuit 101 of the rectifier 100. The bridge circuit 110 rectifies the three-phase ac voltage. A smoothing capacitor 112 is connected to the output of the bridge circuit 110, and the voltage rectified by the bridge circuit 110 is smoothed by the smoothing capacitor 112 to generate a dc voltage Vdc.

Each single-phase input device 120_ i (i ═ 1, 2) has a 1 st input terminal IN1 and a 2 nd input terminal IN2, is capable of operating with the single-phase alternating voltage Vaci input between the 1 st input terminal IN1 and the 2 nd input terminal IN2 as a power supply, and is capable of outputting an error ERRi IN response to the interruption of the single-phase alternating voltage Vaci. The error ERRi is set to invalid (e.g., low L) when the single-phase input device 120_ i is normal, and is asserted (e.g., high H) when the single-phase alternating voltage Vaci of the single-phase input device 120_ i is cut off.

The 1 st input terminal IN1 and the 2 nd input terminal IN2 of each of the plurality of single-phase input devices 120 are connected to different 2 pairs of the plurality of ac input terminals R, S, T. IN the present embodiment, 2 single-phase input devices 120_1 and 120_2 are provided, the 1 st input terminal IN1 and the 2 nd input terminal IN2 of the single-phase input device 120_1 are connected to the R-phase input and the S-phase input, and the 1 st input terminal IN1 and the 2 nd input terminal IN2 of the single-phase input device 120_2 are connected to the S-phase input and the T-phase input. For convenience only, the R phase, S phase, and T phase may be distinguished, and may be replaced.

Although not limited thereto, the single-phase input device 120 is preferably a device provided in the rectifier 100 as a standard device. This will be described later.

The results of error detection (also referred to as error information) ERR1, ERR2 of the plurality of single-phase input devices 120_1, 120_2 are supplied to the controller 130. The controller 130 detects a phase failure based on the error information ERR1 and ERR2 of each of the plurality of single-phase input devices 120. In addition, the controller 130 may be disposed outside the rectifier 100.

The above is the structure of the rectifier 100. Next, the operation thereof will be described. Fig. 2 is a diagram illustrating detection of a phase loss by the rectifier 100 of fig. 1. In a normal state without phase loss, both the 2 error messages ERR1 and ERR2 are invalid (L).

In the case where a phase loss occurs in the R phase, the single-phase ac voltage Vac1 input to the single-phase input device 120_1 is cut off, but the single-phase ac voltage Vac2 input to the single-phase input device 120_2 is normal. Therefore, only the error information ERR1 is asserted.

In the case where a phase loss occurs in the S phase, both the single-phase ac voltage Vac1 input to the single-phase input device 120_1 and the single-phase ac voltage Vac2 input to the single-phase input device 120_2 are cut off. Thus, error information ERR1, ERR2 are both asserted.

In the case where a phase loss occurs in the T-phase, the single-phase ac voltage Vac1 input to the single-phase input device 120_1 is normal, but the single-phase ac voltage Vac2 input to the single-phase input device 120_2 is cut off. Thus, error information ERR2 is asserted.

That is, according to the rectifier 100, the plurality of error information ERR1 to ERR2 are monitored, and when at least one of them is asserted, it can be determined that there is a phase failure.

The present invention may be understood as the block or circuit diagram of fig. 1, or it may relate to various devices and methods derived from the above description, which are not limited to a particular configuration. Hereinafter, more specific structural examples and embodiments will be described for the purpose of facilitating understanding and clarifying the nature and operation of the present invention, and are not intended to narrow the scope of the present invention.

Fig. 3 is a diagram illustrating a rectifier 100A according to embodiment 1. As described above, the single-phase input device 120 is preferably a device originally provided in the rectifier 100. A fan for cooling is generally provided in the power supply device including the rectifier 100, and a fan capable of easily obtaining an AC input (referred to as an AC fan) is provided. Therefore, there are the following advantages: the rectifier 100A uses the AC fan 120A as the single-phase input device 120, and thus, additional hardware is not required to detect the phase loss.

The AC fan 120A is provided with a LOCK detection function, and can generate an error output (LOCK signal LOCK) when the rotation of the fan is stopped due to the foreign matter being caught or the like. In this case, the single-phase input device 120 can be understood as performing an erroneous output when it cannot perform its own function. In addition to the case where the foreign object is the cause, in the case where the alternating-current input voltage of the AC fan 120A is cut off, the rotation of the fan is also stopped, and thus the LOCK signal LOCK is asserted. That is, the LOCK signal LOCK doubles as error information ERR indicating the cutoff of the ac input voltage.

In the present embodiment, the constituent components of the rectifier 100 are housed in the frame 102. An opening (air outlet) 104_1 for discharging hot air and an opening (air inlet) 104_2 for sucking cold air from the outside are provided in the housing 102.

AC fan 120A _1 is provided for air discharge and is disposed in the vicinity of opening 104_ 1. AC fan 120A _2 is provided for air intake, and is disposed in the vicinity of opening 104_ 2. The LOCK signals LOCK1, LOCK2 generated by the AC fans 120A _1, 120A _2 are input into the controller 130.

The main circuit 101 may include a reactor 114 in addition to the bridge circuit 110 and the smoothing capacitor 112. The main circuit 101 may include a fuse or a Breaker (Breaker) on the upstream side of the bridge circuit 110.

If a cut-off of the single-phase alternating voltage is detected in at least one of the plurality of AC fans 120A, that is, if the LOCK signal LOCK is asserted, the controller 130 stops the functional blocks (interlocks) downstream of the rectifier 100. The downstream functional block is not particularly limited, but an inverter, a converter, or the like is exemplified. This prevents rectifier 100A from continuing to operate in the phase-loss state.

Fig. 4 is a diagram illustrating an operation of the rectifier 100 of fig. 3. In a normal state without phase loss, both 2 LOCK signals LOCK1, LOCK2 are inactive (L).

In the case where a phase loss occurs in the R phase, only the LOCK signal LOCK1 is asserted. In the case where a phase loss occurs in the S phase, both LOCK signals LOCK1 and LOCK2 are asserted.

In the event of a phase loss in the T phase, the LOCK signal LOCK2 is asserted.

Further, when the rotation is stopped with a foreign object or the like being caught in AC fan 120A _1, LOCK signal LOCK1 is asserted, and when the rotation is stopped with a foreign object or the like being caught in AC fan 120A _2, LOCK signal LOCK2 is asserted.

The controller 130 monitors 2 LOCK signals LOCK1, LOCK2 and, in the event that at least one is asserted, stops the downstream function block.

According to this embodiment, the rectifier 100A can be protected by interlocking not only in the case where the rotation of the fan motor is stopped but also in the case where a phase loss occurs.

Fig. 5 is a diagram illustrating the structure of AC fan 120A and the connection method thereof. AC fan 120A includes fan motor 122, drive circuit 124, switch 126, and lock detection circuit 128.

The drive circuit 124 drives the fan motor 122 according to the single-phase ac voltage Vac supplied between the 1 st input terminal IN1 and the 2 nd input terminal IN 2. The switch 126 is disposed between the 1 st error detection terminal E1 and the 2 nd error detection terminal E2.

While the fan motor 122 is rotating, the lock detection circuit 128 turns the switch 126 on, and when the stop of the rotation of the fan motor 122 is detected, the lock detection circuit 128 turns the switch 126 off. The rotation stop includes rotation stop caused by interruption of the ac voltage Vac, in addition to rotation stop caused by foreign matter or the like.

The plurality of AC fans 120A _1, 120A _2 are connected in series with each other by switches 126. That is, terminal E2 of AC fan 120A _1 is connected to terminal E1 of AC fan 120A _ 2. Terminal E2 of AC fan 120A _2 may be connected to ground and terminal E1 of AC fan 120A _1 may be pulled up by resistor Rp. Controller 130 determines whether or not there is an abnormality based on the state of terminal E1 of AC fan 120A _ 1. That is, when the 2 AC fans 120A _1 and 120A _2 are normal, the terminal E1 of the AC fan 120A _1 is pulled down to the low potential (GND) via the 2 switches 126, and if an abnormality occurs in at least one of the 2 AC fans 120A _1 and 120A _2, the terminal E1 of the AC fan 120A _1 is pulled up to the high potential (VDD) via the resistor Rp.

According to the configuration of fig. 5, controller 130 can detect the presence or absence of a default phase by monitoring the state of only one node (terminal E1 of AC fan 120A _ 1). For example, in the case where the controller 130 is implemented by a microcontroller, the number of pins of the microcontroller is limited, but in this configuration, only 1 pin is required for detecting a phase failure.

In addition, in the case where there is a margin in the number of pins of the controller 130, the terminals E2 of the AC fans 120A _1 and 120A _2 may be grounded, and the terminals E1 may be input to the respective pins of the microcontroller.

Fig. 6 is a block diagram of a rectifier 100B according to embodiment 2. The rectifier 100B includes 3 single-phase input devices 120_1 to 120_ 3. The 1 st input terminal IN1 and the 2 nd input terminal IN2 of the 3 rd single-phase input device 120_3 are connected to the T-phase input and the R-phase input, and the 3 rd single-phase input device 120_3 receives the voltage Vac3 between the T-phase and the R-phase. The controller 130 monitors error information ERR1 ERR3 of 3 single-phase input devices 120_1 to 120_ 3.

Fig. 7 is a diagram illustrating phase loss detection of rectifier 100B of fig. 6. In a normal state without phase loss, all of the 3 error messages ERR1 to ERR3 are invalid (L).

When a phase loss occurs in the R phase, the single-phase ac voltages Vac1 and Vac3 input to the single-phase input devices 120_1 and 120_3 are cut off, and the single-phase ac voltage Vac2 input to the single-phase input device 120_2 is normal. Thus, error information ERR1, ERR3 is asserted.

When a phase loss occurs in the S phase, the single-phase ac voltages Vac1 and Vac2 input to the single-phase input devices 120_1 and 120_2 are cut off, and the single-phase ac voltage Vac3 input to the single-phase input device 120_3 is normal. Thus, error information ERR1, ERR2 is asserted.

When a phase loss occurs in the T phase, the single-phase ac voltages Vac2 and Vac3 input to the single-phase input devices 120_2 and 120_3 are cut off, and the single-phase ac voltage Vac1 input to the single-phase input device 120_1 is normal. Thus, error information ERR2, ERR3 is asserted.

According to the rectifier 100B, the error information ERR1 to ERR3 are monitored, and when at least one of them is asserted, it can be determined that a phase failure has occurred. According to embodiment 2, more reliable error detection is provided compared to a configuration using 2 single-phase input devices 120.

In addition, according to embodiment 2, there are also advantages as follows: by individually monitoring the plurality of error information ERR1 to ERR3, it is possible to distinguish which phase the phase generates the phase loss.

(use)

Next, the use of the rectifier 100 will be explained. The rectifier 100 can be applied to various power supply devices, for example, a power supply device of the laser processing device 900. Fig. 8 is a diagram illustrating a laser processing apparatus 900. The laser processing apparatus 900 irradiates a laser pulse 904 to the object 902 to process the object 902. The type of the object 902 is not particularly limited, and examples of the type of processing include drilling (boring), cutting, and the like, but the object is not limited thereto.

The laser processing apparatus 900 includes a laser apparatus 800, an optical system 910, a control device 920, and a table 930. The object 902 is placed on the table 930 and fixed as necessary. The table 930 positions the object 902 based on the position control signal S2 from the controller 920, and scans the object 902 relative to the irradiation position of the laser pulse 904. The stage 930 may have 1, 2 (XY) or 3 (XYZ) axes.

The laser apparatus 800 oscillates in accordance with a trigger signal (excitation signal) S1 from the control apparatus 920 to generate a laser pulse 906. The optical system 910 irradiates the object 902 with the laser pulse 906. The optical system 910 may include, but is not limited to, a mirror group for introducing a light beam into the object 902, a lens for shaping the light beam, an aperture, and the like.

The control device 920 centrally controls the laser processing device 900. Specifically, the controller 920 intermittently outputs the excitation signal S1 to the laser device 800. The controller 920 generates a position control signal S2 for controlling the table 930 based on the data (method) describing the machining process in the position control signal S2.

Fig. 9 is a block diagram of the laser apparatus 800 of fig. 8. The laser device 800 includes a laser cavity 200 and a power supply device 250.

The laser cavity 200 is shown as an equivalent circuit. An electrostatic capacitance C and a resistance component R are included between the pair of

discharge electrodes

202, 204. The electrostatic capacitance C forms a resonant circuit 210 together with the inductor L. The resonant frequency of the resonant circuit 210 is set to f _RES . The inductor L includes at least one of parasitic inductances of the inductor component and the wiring or the substrate.

The power supply device 250 applies a high-frequency voltage V to the resonant circuit 210 _RF . High frequency voltage V _RF Frequency f of _RF (hereinafter, referred to as synchronous frequency) is set at the frequency f of the resonant circuit _RES Is detected. By applying a high-frequency voltage V _RF A discharge current flows between the pair of

discharge electrodes

202, 204. The laser medium gas is excited by the discharge current to form a reverse distribution.

The power supply device 250 includes a rectifier 100, a charging power supply 300, and a high-frequency power supply 400. Rectifier 100 rectifies and smoothes three-phase ac voltage to generate dc voltage V _DC . The charging power supply 300 includes a switching power supply such as a boost converter or a buck converter, and outputs a voltage V to the rectifier 100 _DC Boosting is performed to generate a high voltage (DC link voltage) Vhigh.

An input of the high frequency power supply 400 is connected to the DC bus 310 and receives the DC bus voltage Vhigh. The high frequency power source 400 generates a voltage having a resonant frequency f _RES Same frequency (synchronous frequency) f _RF High frequency voltage V of _RF And supplied into the laser resonator 200. The configuration of the high-frequency power supply 400 is not limited, and may include converting the dc voltage Vhigh into the ac voltage V _AC H-bridge circuit (inverter) 402 and output voltage V to H-bridge circuit 402 _AC A transformer 404 for boosting.

As described above, the rectifier 100 is configured to be able to detect a phase loss of the three-phase ac. When the phase loss state is detected, the controller 130 of the rectifier 100 outputs the interlock signal LOCK to a unit (specifically, the charging power supply 300 or the high-frequency power supply 400) downstream of the rectifier 100. The charging power supply 300 or the high frequency power supply 400 stops operating in response to the interlock signal LOCK.

With this configuration, the power supply device 250 can be prevented from continuing to operate in the phase-loss state.

The embodiments have been described above. The embodiment is an example, and those skilled in the art will understand that various modifications may be made to the combination of each constituent element or each processing step, and such modifications are also within the scope of the present invention. Hereinafter, such a modification will be described.

The single-phase input device 120 may be any device that has a single-phase ac input and can output some kind of error information when the single-phase input is cut off, without limitation to the kind thereof. For example, the single-phase input device 120 can use another device having a lock detection function capable of detecting the motor and its lock state. For example, the single-phase input device 120 may be an AC pump that circulates a cooling medium.

The application of the rectifier 100 is not limited to the power supply of the laser device, and can be widely applied to various devices, machines, apparatuses, and apparatuses that operate using an ac voltage as a power supply.

The number of alternating current phases input to the rectifier 100 is not limited to 3, and may be larger than 3.

The embodiments are merely illustrative of the principles and applications of the present invention, and many modifications and changes in arrangement are possible without departing from the scope of the invention defined in the claims.

Claims

1. A rectifier for converting a multiphase AC voltage into a DC voltage, comprising:

a plurality of ac input terminals receiving the multiphase ac voltage;

a bridge circuit rectifying the multiphase AC voltage; and

a plurality of single-phase input devices each operable with a single-phase alternating-current voltage input between the 1 st input terminal and the 2 nd input terminal as a power source and capable of detecting an error in response to a cut-off of the single-phase alternating-current voltage,

the 1 st input terminal and the 2 nd input terminal of each of the plurality of single-phase input devices are connected to different 2 pairs of the plurality of ac input terminals.

2. The rectifier according to claim 1,

the plurality of single-phase input devices are each capable of outputting a signal indicative of an error condition when they are unable to perform their own functions.

3. The rectifier of claim 1 or 2 further having a controller that processes results of error detection in the plurality of single phase input devices.

4. The rectifier of claim 3,

the controller stops a functional block downstream of the rectifier if an error condition is detected in at least one of the plurality of single phase input devices.

5. The rectifier according to any one of claims 1 to 4,

the single-phase input device is an AC fan.

6. The rectifier according to any one of claims 1 to 5,

the single-phase input device includes:

1 st error detection terminal;

2 nd error detection terminal; and

a switch provided between the 1 st error detection terminal and the 2 nd error detection terminal and turned on during the input of the single-phase alternating-current voltage,

the plurality of single-phase input devices are connected in series with each other.

7. The rectifier according to any one of claims 1 to 6,

the multi-phase alternating current voltage comprises 3 phases including an R phase, an S phase and a T phase,

the plurality of single-phase input devices includes:

1 st single-phase input device, which applies voltage between the R phase and the S phase to single-phase input thereof; and

a 2 nd single phase input device to which a voltage between the S phase and the T phase is applied to a single phase input thereof.

8. The rectifier according to claim 7,

the 1 st single-phase input device is an AC fan for air suction,

the 2 nd single phase input device is an AC fan for exhausting.

9. The rectifier according to claim 7 or 8,

the plurality of single phase input devices further includes a 3 rd single phase input device to which a voltage between the T phase and the R phase is applied to a single phase input thereof.

10. A power supply device for laser, comprising:

the rectifier of any one of claims 1 to 9;

a converter for boosting a DC output voltage of the rectifier; and

and a high-frequency power supply for converting the output voltage of the converter into an alternating-current high voltage.