JP2002129397A - Power supply for high-speed polarity inversion plating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly plate an article such as a printed circuit board by rapidly inversing a polarity of a power supply. SOLUTION: This power supply comprises a series circuit of a first electric reactor 4A and a first main rapidly-switching on/off element 8A in a route consisting of one end of a first DC power supply 2A, the other end of a second DC power supply 2B, and one end of a load; a series circuit of a second electric reactor 4B and a second main switching element 2B which turns on and off in accordance with a switching of the first main switching element, in a route consisting of one end of the second DC power supply, the other end of the first DC power supply, and the other end of the load; a first auxiliary switching element 10A which turns on and off in accordance with a switching of the first main switching element, between an output end of the first reactor and the other end of the first DC power supply; a second auxiliary switching element 10B which turns on and off in accordance with a switching of the first main switching element, between an output end of the second reactor and the other end of the second DC power supply; and furthermore, detecting voltage between both ends of the above first or second auxiliary switching element, and making the above first or second auxiliary switching element turn on when a detected signal of the first or the second voltage detecting device is a predetermined voltage or over.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed current reversal plating power supply device for reversing the current at a high speed and uniformly plating an object to be plated such as a printed wiring board.

[0002]

2. Description of the Related Art By reversing the polarity at a high speed, the current is reversed, the plating is interrupted or dissolved by a negative current, and the plating is interrupted or melted by a positive current. .

However, in a printed wiring board of a multi-layer substrate in which components to be plated can be integrated at a high density, it becomes difficult to obtain a uniform plating in the through hole as the plate layer becomes larger. In particular, it has been found that uniform plating cannot be obtained in the through-hole unless the negative current flows for a sufficiently shorter time than the positive current of the plating and a negative current sufficiently larger than the positive current flows in the through-hole. .

Therefore, the applicant proposed in Japanese Patent Application Laid-Open No. 2000-92841 a power supply device which converts the polarity at a high speed and performs uniform plating on an object to be plated such as a multilayer printed circuit board. That is, the power supply device proposed by the applicant is a power supply as shown in FIG. In FIG. 5, DC power supplies 2A and 2B are formed by rectifying a commercial AC power supply. In some cases, a DC obtained by rectifying an AC power supply is converted into a high frequency by an inverter and rectified again. 4A,
4B is an output of one of the DC power supplies 2A and 2B,
For example, the first and second terminals connected to the positive outputs 2A1 and 2B1
Reactors, 6A and 6B are backflow prevention diodes whose anodes are connected to the outputs of the first and second reactors 4A and 4B, respectively, and 8A and 8B are main IGBs whose collectors are connected to the cathodes of the respective backflow prevention diodes 6A and 6B.
T, and the respective emitters of the IGBTs 8A and 8B are connected to the other outputs of the respective DC power supplies 2B and 2A, for example, the negative outputs 2B2 and 2A2.

A short-circuit 10A has a collector connected to a connection point C between the first reactor 4A and one backflow prevention diode 6A, and an emitter connected to another output 2A2 of the first DC power supply 2A. One auxiliary IGBT.
A short-circuit second terminal 10B has a collector connected to a connection point D between the second reactor 4B and the other backflow prevention diode 6B, and an emitter connected to another output 2B2 of the second DC power supply 2B. This is an auxiliary IGBT. Reference numeral 12 denotes a load of the object to be plated connected between the output of the IGBT 8A and the output of the IGBT 8B. 14 is the main IGBT8
A, 8B, and a control device that outputs control signals to the auxiliary IGBTs 10A, 10B. Furthermore, the main IGBTs 8A and 8B
And snubber circuits 16A, 16A between the collectors and emitters of auxiliary IGBTs 10A, 10B, respectively.
B and 18A, 18B are connected. These snubber circuits 16A, 16B, 18A, 18B are provided with, for example, a series circuit of a diode and a film capacitor, and a discharge resistor in parallel with the film capacitor.

FIG. 6 is a waveform diagram of each part, and FIG. 6A shows a waveform of a current flowing through the load 12, and FIGS. 6B to 6E.
Are the first main IGBT 8A and the first auxiliary IGBT 10 respectively.
A, gate signal waveforms of the second main IGBT 8B and the second auxiliary IGBT 10B are shown. Now, before the time t1 shown in FIG. 6, the gate signal shown in FIG. 6D is input to the second main IGBT 8B, and the second DC power supply 2B outputs the second reactor 4B, the second diode 6B, 2 main IGBT8
A positive current shown in FIG. 6A flows to the load 12 via B. From these, the plating is interrupted or dissolved.

On the other hand, before the time t1, the first auxiliary IG
As shown in FIG. 6C, a gate signal is input to the BT 10A, and the first DC power supply 2A, the first reactor 4A,
A current flows through the first auxiliary IGBT 10A and the first DC power supply 2A, and energy is stored in the first reactor 4A.

Then, at time t1, the second main IGB
At T8B, the gate signal of the first auxiliary IGBT 10A is turned off, and the gate signal is input to the first main IGBT 8A as shown in FIG. When a gate signal is input to the first main IGBT 8A, the first DC power supply 2A, first reactor 4A, first diode 6A, first main IGBT 8A, load 12, first DC power supply 2A, and FIG. A negative current flows as shown. At this time, the output current of the first DC power supply device 2A and the current obtained by releasing the energy stored in the first reactor 4A and flowing to the load 12 flow. Therefore, the current flowing through the load 12 rises sharply. Thereby, the object to be plated of the load 12 is plated.

On the other hand, at time t1, the second auxiliary IGBT 10B
Also, a gate signal is input as shown in FIG.
A current flows through the second DC power supply 2B, the second reactor 4B, the second auxiliary IGBT 10B, and the second DC power supply 2B.
Energy is stored in second reactor 4B.

Next, at time t2, the first main IGBT 8
A, the gate signal of the second auxiliary IGBT 10B is turned off, and the gate signal is input to the second main IGBT 8B as shown in FIG. When the gate signal is input to the second main IGBT 8B, the second DC power supply 2B, the reactor 4B, the diode 6B, the second main IGBT 8B, the load 12, and the second DC power supply 2B become positive as shown in FIG. Electric current flows. At this time, the output current of the second DC power supply
The current accumulated by discharging the energy stored in the reactor 4B flows to the load 12. Therefore, the load 12
The current flowing through is rapidly discharged. As a result, the plating is interrupted or dissolved.

On the other hand, at time t2, the first auxiliary IGBT 10A
As shown in FIG. 6C, a gate signal is input to the first DC power supply 2A, the first reactor 4A, and the first auxiliary I
A current flows through the GBT 10A and the first DC power supply 2A, and energy is stored in the reactor 4A.

Hereinafter, the operation is sequentially repeated. First main IGBT8A
By switching between the second main IGBT 8B and the second main IGBT 10B at a high speed, and switching between the second auxiliary IGBT 10B and the first auxiliary IGBT 10A at a high speed, it is possible to obtain a plating power supply device that reverses the current at a high speed.

If the time during which the negative current for plating flows is T1 and the period during which the positive current for interrupting or melting the plating flows is T2, the inversion ratio of T2 / (T1 + T2) controls the controller 14. This is done by: Main IG
This can be performed by changing the periods of the gate signals of the BTs 8A and 8B and the auxiliary IGBTs 10A and 10B.
Further, although not shown, the magnitude of the current flowing through the load 12 can be detected by detecting the current flowing through the load 12 and controlling the control device 14 according to the detection signal.

[0014]

The object to be plated is hung on a hanger in a yard, carried to a plating tank by a transfer device, and put into the plating tank. Then, a current is passed from the power supply device to the object to be plated, and plating is performed. Further, the object to be plated may be moved in the plating tank by the transfer device.

For this reason, the load may not be able to make sufficient contact with the power supply hanger, or may not be able to make contact due to the vibration of the transfer device, or rust may occur due to the atmosphere at the plating site, and the load may not contact the power supply portion. When the load and the power supply unit cannot contact each other as described above, the auxiliary IGBT 1
A high voltage is applied to both ends of 0A and 10B by the energy stored in the reactors 4A and 4B. For this reason, the snubber circuits 18A and 18B connected in parallel to the short-circuit auxiliary IGBTs 10A and 10B cannot operate, and the IGBTs 10A and 10B do not operate.
B may be damaged.

[0016]

According to a first aspect of the present invention, there is provided a power supply apparatus for plating a high-speed current reversal, comprising: a first DC power supply;
Provide a DC power supply. A first reactor connected between one output terminal of the first DC power supply, the other output terminal of the second DC power supply, and one end of a load;
A series circuit with the first main switching element to be turned off is provided. One output terminal of the second DC power supply,
A second reactor and a second main switching element that is turned off and on in a complementary manner corresponding to the on and off of the first main switching element between the other output end of the DC power supply device and the other end of the load; Are provided. A first auxiliary switching element that is turned on and off in a complementary manner corresponding to the on / off of the first main switching element is provided between the output of the first reactor and the other output terminal of the first DC power supply; A second auxiliary switching element is provided between the output of the second reactor and the other output terminal of the second DC power supply, which turns off and on in a complementary manner in accordance with the on and off of the second main switching element. . Further, the first and second auxiliary switching elements are connected in parallel with the first and second auxiliary switching elements, respectively.
A first and a second clamping circuit comprising a clamping diode, and first and second clamping capacitors connected in series to the first and second clamping diodes, respectively, and charged at a peak voltage in a steady state; A first detecting means for detecting a voltage between both ends of the first or second auxiliary switching element;
Alternatively, a second voltage detector is provided, and when the detection signal of the first or second voltage detector is equal to or higher than a predetermined voltage, the first or second voltage detector is provided.
And a control device for turning on the auxiliary switching element.

According to a second aspect of the present invention, in the power supply device for high-speed current reversal plating, the first and second clamping capacitors have an electrolytic capacity sufficiently larger than a snubber capacitor connected to the first and second auxiliary switching elements. It is a capacitor.

When an ON signal is input to the second main switching element and turned on, a current, for example, a positive current, flows to the load via the second DC power supply, the second reactor, and the second main switching element to be melted. . At this time, the ON signal is also input to the first auxiliary switching element, and a current flows through the first reactor and the first auxiliary switching element. This current causes energy to be stored in the first reactor.

Next, when the ON signals of the second main switching element and the first auxiliary switching element are turned off, these two switching elements are turned off. When an ON signal is input to the first main switching element and turned on, a current flows to the load via the first DC power supply, the first reactor, and the first main switching element. At this time, when the first auxiliary switching element is turned off, a voltage for adding the output of the first DC power supply is generated in the first reactor, a steep negative current flows in the load, and the object to be plated is plated. . Further, an ON signal is also input to the second auxiliary switching element, a current flows through the second DC power supply, the second reactor, and the second auxiliary switching element, and energy is accumulated in the second reactor.

Next, when the ON signals of the first main switching element and the second auxiliary switching element are turned off, both of these switching elements are turned off. Then, when an ON signal is input to the second main switching element and turned on, a positive current flows to the load via the second DC power supply, the second reactor, and the second main switching element. At this time, when the second auxiliary switching element is turned off, a voltage for adding the output of the second DC power supply is generated in the second reactor, and a steep positive current flows through the load. Further, an ON signal is also input to the first auxiliary switching element, a current flows through the first DC power supply, the first reactor, and the first auxiliary switching element, and energy is accumulated in the first reactor. The following is repeated sequentially.

The current flowing through the first or second main switching element rises steeply, and a current that reverses at a high speed can flow through the load by turning on and off the first and second main switching elements at high speed.

When the load is released, a high voltage tends to be generated in the first or second auxiliary switching element that is turned off by the stored energy of the reactor, but the stored energy of the reactor is absorbed by the clamping capacitor. , The rate of increase of the voltage applied to the first or second auxiliary switching element per unit time is small, and the first or second auxiliary switching element is not damaged. Then, the voltage applied to the first or second auxiliary switching element further increases due to the stored energy of the reactor, and the first or second
When the detection voltage detected by the voltage detector becomes equal to or higher than a predetermined voltage, an ON signal is input to the first or second auxiliary switching element to be turned on, and no high voltage is applied to the first or second auxiliary switching element. .

According to a third aspect of the present invention, there is provided a power supply apparatus for high-speed current reversal plating, wherein the first and second clamp circuits are respectively connected in parallel with the first and second auxiliary switching elements. A first or second voltage detector for detecting a voltage across the second auxiliary switching element; a rectifier circuit for rectifying a voltage applied to a load; and a rectifier circuit connected to an output of the rectifier circuit and charged with a steady-state peak voltage. A third clamping capacitor, a third voltage detector for detecting both ends of the third clamping capacitor, and the first or second auxiliary switching when a detection signal of the third voltage detector is equal to or higher than a predetermined voltage. Instead of a control device for turning on the element.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to FIG. 1 showing an embodiment of the present invention. 1 differs from FIG. 4 in that an electrolytic capacitor for clamping and a voltage detector are provided at both ends of the auxiliary IGBT for short-circuit, and when the load is released, the excessive voltage generated in the reactor is absorbed and the electrolytic capacitor of the electrolytic capacitor is removed. When the voltage between both ends exceeds a predetermined voltage, the auxiliary I
This is to short-circuit the GBT.

That is, reference numerals 2A and 2B denote DC power supply devices, which are generally formed by rectifying a commercial AC power supply with a thyristor or the like. In some cases, a rectified DC from an AC power supply is converted to a high frequency by a built-in inverter and then rectified again by a diode to form the AC power supply. 4A, 4
B is an output of one of the DC power supplies 2A and 2B, for example, the first and second reactors 6A and 6B connected to the positive outputs 2A1 and 2B1 are anodes of the outputs of the first and second reactors 4A and 4B, respectively. Are connected to the cathodes of the backflow prevention diodes 6A and 6B, respectively. The first and second main IGBTs 8A and 8B have the collectors connected to the cathodes of the backflow prevention diodes 6A and 6B, respectively.
B have respective DC power supplies 2B,
It is connected to the other output of 2A, for example, negative outputs 2B2 and 2A2.

10A is the first reactor 4A and one of the first reactors 4A.
The collector is connected to a connection point C of the backflow prevention diode 6A with the anode, and the emitter is a first auxiliary IGBT for short-circuiting whose emitter is connected to another output 2A2 of the first DC power supply 2A. 10B is the second reactor 4B and the other second reactor 4B.
The collector is connected to a connection point D with the anode of the backflow prevention diode 6B, and the emitter is a second auxiliary IGBT for short-circuiting whose emitter is connected to another output 2B2 of the second DC power supply 2B. 12 is an output of the first main IGBT 8A and a second main IGBT 8A.
This is the load of the plating object connected between the output of the BT 8B. 22 is the main IGBT 8A, 8B, auxiliary IGBT 10
A, a control device that outputs a control signal to 10B.

Further, the main IGBTs 8A and 8B and the auxiliary I
Snubber circuits 16A, 16B and 18A, 18B are provided between collectors and emitters of GBTs 10A, 10B, respectively.
Is connected. These snubber circuits 16A, 16B,
18A and 18B are, for example, diodes 16A, respectively.
c, 16Bc, 18Ac, 18Bc and a snubber capacitor, for example, film capacitors 16Aa, 16Ba, 1
8Aa and 18Ba and a snubber capacitor 1
Snubber resistors 16Ab, 16Bb, 18Ab, 18Bb are provided in parallel with 6Aa, 16Ba, 18Aa, 18Ba.

Further, the first and second auxiliary IGBTs 10A, 1
First and second clamp circuits 28A and 28B are connected to both ends of 0B, that is, between the collector and the emitter, respectively. These clamp circuits 28A and 28B are composed of a series circuit of, for example, clamp diodes 28Ac and 28Bc, and clamp capacitors 28Aa and 28Ba of electrolytic capacitors having a capacity sufficiently larger than the capacity of the film capacitor of the snubber circuit, for example, 2000 μF. Clamping resistors 28Ab and 28Bb are provided in parallel with the clamp capacitors 28Aa and 28Ba, respectively. At the same time, the first and second auxiliary IGBTs 10A,
10B, first and second voltage detectors 24A and 24B are provided at both ends to detect the respective voltages, and the detection signals detected by the first and second voltage detectors 24A and 24B are respectively compared with the first and second comparison signals. The signals are input to the devices 26A and 26B. First
The second comparators 26A and 26B compare the detection signal with a built-in reference value, and when the detection signal becomes higher than the reference value, the control device 2
2 to output an output signal.

FIG. 2 is a waveform diagram of each part. FIG. 2A shows a waveform of a current flowing through the load 12, and FIGS. 2B to 2E.
Are the first main IGBT 8A and the first auxiliary IGBT 10 respectively.
A, gate signal waveforms of the second main IGBT 8B and the second auxiliary IGBT 10B are shown. Now, before the time t1 shown in FIG. 2, the gate signal shown in FIG. 2D is input to the second main IGBT 8B, and the second DC power supply 2B, the second reactor 4B, the second diode 6B, the second main IGBT 8B A current shown in FIG. 2A, for example, a positive current flows through the load via the IGBT 8B and the load 12. From these, the plating is interrupted or dissolved.

Before the time t1, the first auxiliary IG
The gate signal is input to the BT 10A as shown in FIG. 2C, and the first DC power supply 2A, the first reactor 4A,
A current flows through the first auxiliary IGBT 10A and the first DC power supply 2A, and energy is stored in the first reactor 4A.

Then, at time t1, the second main IGB
At T8B, the gate signal of the first auxiliary IGBT 10A is turned off, and the gate signal is input to the first main IGBT 8A as shown in FIG. When a gate signal is input to the first main IGBT 8A, the first DC power supply 2A, the first reactor 4A, the first diode 6A, the first main IGBT 8A, the load 12, and the first DC power supply 2A are transmitted to the first DC power supply 2A as shown in FIG. )). At this time, the first DC power supply 2A
The output current of the first reactor 4A and the energy accumulated in the first reactor 4A are released, and the added current flows to the load 12. Then, the current flowing through the load 12 rises sharply. Thereby, the object to be plated of the load 12 is plated.

On the other hand, at time t1, the second auxiliary IGBT 10B
Also, a gate signal is input as shown in FIG.
A current flows through the second DC power supply 2B, the second reactor 4B, the second auxiliary IGBT 10B, and the second DC power supply 2B.
Energy is stored in second reactor 4B.

Next, at time t2, the first main IGBT 8
A, the gate signal of the second auxiliary IGBT 10B is turned off, and the gate signal is input to the second main IGBT 8B as shown in FIG. When the gate signal is input to the main IGBT 8B, the second DC power supply 2B, the second reactor 4B, the second diode 6B, the second main IGBT 8B, the load 12, and the second DC power supply 2B are shown in FIG. Positive current flows. At this time, the output current of the second DC power supply device 2B and the current obtained by releasing the energy stored in the second reactor 4B and flowing to the load 12 flow. For this reason,
The current flowing through the load 12 is rapidly discharged. As a result, the plating is interrupted or dissolved.

On the other hand, at time t2, the first auxiliary IGBT 10A
As shown in FIG. 2C, a gate signal is also input to the first DC power supply 2A, the first reactor 4A, and the first auxiliary I
A current flows through the GBT 10A and the first DC power supply 2A, and energy is stored in the reactor 4A.

The above operation is sequentially repeated. First main IGBT8A
By switching between the second main IGBT 8B and the second auxiliary IGBT 10B at a high speed, and switching between the second auxiliary IGBT 10B and the first auxiliary IGBT 10A at a high speed, it is possible to obtain a plating power supply device capable of reversing the current at a high speed.

If the time during which the negative current for plating flows is T1 and the period during which the positive current for interrupting or melting the plating flows is T2, the reversal ratio of T2 / (T1 + T2) controls the controller 22. This is done by: , Lord I
This can be performed by changing the periods of the gate signals of the GBTs 8A and 8B and the auxiliary IGBTs 10A and 10B. Further, although not shown, the magnitude of the current flowing through the load 12 can be detected by detecting the current flowing through the load 12 and controlling the control device 22 according to the detection signal.

Next, the second DC power supply 2B, the second reactor 4B, the second reactor 6B, the second main IGBT 8B,
At time t5 in FIG. 2 in which current flows through the load 12, a case where contact between the plating object of the load 12 and a power supply unit such as a hanger becomes impossible will be described.

Until immediately before time t5, the second auxiliary IGBT 10B
Current flows through the second DC power supply 2B, the second reactor 4B, the diode 28Bc, the clamp capacitor 28Ba, and the second DC power supply 2B, and the second auxiliary IGBT 10
The battery is charged up to the voltage including the surge voltage due to the switching in the normal state of B, that is, the voltage E in FIG.

At time t5, when contact between the object to be plated of the load 12 and a power supply unit such as a hanger becomes impossible, the current flowing through the second reactor 4B is cut off, and the voltage indicated by E in FIG. A larger overvoltage occurs. At this time, the energy stored in the second reactor 4B is absorbed by the clamping capacitor 28Ba, the rate of increase in the voltage applied to the second auxiliary IGBT 10B per unit time is small, and the second auxiliary IGBT 10B is not damaged at this rise. When the excessive voltage rises as shown in FIG. 3 due to the second reactor 4B and the wiring inductance, the second voltage detector 24B detects this voltage. The detection signal is compared with the reference value by the second comparator 26B, and when the voltage of the second IGBT 10B reaches the voltage at the point F, an output signal is output from the comparator 26B to the control device 22, as shown in FIG. Then, the gate signal of the second main IGBT 8B is instructed to be turned off, and as shown in FIG. 2E, the gate signal of the second auxiliary IGBT 10B is instructed to be turned on. With this command signal, the second main IGBT 8B is turned off, and the second auxiliary IGBT 8B is turned off.
The BT element 10B turns on. Thereby, the energy stored in second reactor 4B is transferred to second auxiliary IGBT 10B.
B is collected by the DC power supply 2B. Second auxiliary I
No high voltage is applied to the GBT 10B, and the second
The auxiliary IGBT 10B is protected.

FIG. 2 shows the first auxiliary IGBT 10A.
The gate signal is continuously turned on as shown in FIG.
Further, the energy of the second reactor 4B is changed to the second auxiliary I
After being collected by the second DC power supply 2B via the GBT 10B, the control device 22 outputs an off command signal to the DC power supplies 2B and 2A, and turns off both the DC power supplies 2B and 2A. Thereby, the first and second reactors 4
A, 4B and the first and second auxiliary IGBTs 10A, 10B no longer flow current, and the first and second auxiliary IGBTs 10A, 10B
Both A and 10B are protected. Further, the display device 30 indicates that the load 12 has been released. As a result, the operator checks the contact state of the load and shifts the load to a normal state. A reset switch 32 is used at the time of restart.

In the above embodiment, when the load 12 is released, the auxiliary IGBT 10B is turned on, and the energy of the second reactor 4B is recovered by the second DC power supply 2B via the second auxiliary IGBT 10B. Although the device is shut off, after the auxiliary IGBT is short-circuited, it can be opened again after a predetermined time to allow current to flow through the load. Then, when the load returns from the open state to the short circuit state, the high-speed current reversal plating power supply device can be normally operated. Also, when the voltage detector operates again, a command is issued from the control device 24 to turn on the auxiliary IGBT, so that the DC power supply device can be shut off.

FIG. 4 shows first and second clamp circuits 28A and 28B connected in parallel with the first and second auxiliary switching elements 10A and 10B shown in FIG.
Alternatively, a first or second voltage detector 24A, which detects a voltage between both ends of the second auxiliary switching elements 10A, 10B,
24B and the voltage applied to the load 12 by the diode 35
A rectifier circuit 35 for rectification by A to D, a third clamp capacitor 36 connected to the output of the rectifier circuit and charged with a peak voltage in a steady state, and a third voltage for detecting both ends of the third clamp capacitor 35. A detector 38, a third comparator 39 for comparing a detection signal detected by the third voltage detector 38 with a built-in reference value, and the first signal when the detection signal of the third voltage detector is equal to or higher than a predetermined voltage. Alternatively, it is replaced with a control device for turning on the second auxiliary switching element. The operation of the device of FIG. 4 operates similarly to that of FIG.

In the above embodiment, the second main IGBT
While the ON operation of the second auxiliary IGBT during the period when is turned on is described, the first auxiliary IGBT can be turned on when the load is released during the period when the first main IGBT is on. Further, another switching element such as an FET or a bipolar transistor can be used instead of the IGBT.

[0044]

According to the present invention, when the load is released, an excessive voltage tends to be generated in the first or second auxiliary switching element which is turned off by the stored energy of the reactor. And the first or second auxiliary switching element is protected. The excessive voltage is detected by the first or second voltage detector, and when the detected voltage exceeds a predetermined voltage, the first or second auxiliary switching element is turned on, and the first or second auxiliary switching element is supplied with a high voltage. Is not applied. For this reason, it is not necessary to adopt a snubber circuit provided in parallel with the first or second auxiliary switching having a capacity corresponding to a high voltage due to the energy stored in the reactor as in the related art.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a power supply device for high-speed current reversal plating of the present invention.

FIG. 2 is a waveform chart of each unit in FIG. 1;

FIG. 3 is a voltage waveform diagram applied to an auxiliary switching element of FIG. 1;

FIG. 4 is a block diagram showing another embodiment of the present invention.

FIG. 5 is a block diagram of a conventional power supply device for high-speed current reversal plating.

FIG. 6 is a waveform chart of each part in FIG. 5;

[Explanation of symbols]

 2A (first) DC power supply 2B (second) DC power supply 4A (first) reactor 4B (second) reactor 6A, 6B diode 8A (first) main switching element (IGBT) 8B (second) main switching Element (IGBT) 10A (First) Auxiliary switching element (IGBT) 10B (Second) Auxiliary switching element (IGBT) 12 Load (plated object) 16A, 16B, 18A, 18B Snubber circuit 22 Controller 24A, 24B Voltage detection 26A, 26B Comparator 28A, 28B Clamp circuit 28Aa, 28Ba Clamp condenser

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H730 AA20 AS00 BB14 BB82 CC01 DD03 DD41 XX04 XX12 XX23 XX26 XX32 XX42 XX50

Claims (3)

[Claims] A first DC power supply; a second DC power supply; one output terminal of the first DC power supply;
A first reactor provided between the other output terminal of the DC power supply device and one end of the load;
A series circuit with a main switching element, a second reactor provided between one output terminal of the second DC power supply, the other output terminal of the first DC power supply, and the other end of the load; A series circuit of a second main switching element that turns off and on complementarily in response to the on and off of the first main switching element, an output of the first reactor, and the other output terminal of the first DC power supply device; A first auxiliary switching element that turns off and on complementarily in response to the on and off of the first main switching element during the time between the output of the second reactor and the other output terminal of the second DC power supply device In the meantime, a second auxiliary switching element that turns off and on complementarily in response to the on and off of the second main switching element is connected in parallel with the first and second auxiliary switching elements, respectively. Clamp A first and a second clamp circuit comprising a first and a second clamp capacitor connected in series to the diode and the first and the second clamp diodes, respectively, and charged at a peak voltage in a steady state; A first or second voltage detector for detecting both ends of the second auxiliary switching element, and the first or second auxiliary switching element when a detection signal of the first or second voltage detector is equal to or higher than a predetermined voltage. A power device for high-speed current reversal plating, comprising a control device to be turned on. 2. The high-speed current reversal plating according to claim 1, wherein said first and second clamping capacitors are electrolytic capacitors having a capacity sufficiently larger than a snubber capacitor connected to said first and second auxiliary switching elements. Power supply. 3. A first DC power supply, a second DC power supply, one output terminal of the first DC power supply, and the second DC power supply.
A first reactor provided between the other output terminal of the DC power supply device and one end of the load;
A series circuit with a main switching element, a second reactor provided between one output terminal of the second DC power supply, the other output terminal of the first DC power supply, and the other end of the load; A series circuit of a second main switching element that turns off and on complementarily in response to the on and off of the first main switching element, an output of the first reactor, and the other output terminal of the first DC power supply device; A first auxiliary switching element that turns off and on complementarily in response to the on and off of the first main switching element during the time between the output of the second reactor and the other output terminal of the second DC power supply device In the meantime, a second auxiliary switching element that turns off and on complementarily in response to the on and off of the second main switching element, a rectifier circuit that rectifies a voltage applied to the load, and an output of the rectifier circuit Settled A third clamping capacitor charged at the peak voltage, a third voltage detector for detecting both ends of the third clamping capacitor, and the third voltage detector when the detection signal of the third voltage detector is equal to or higher than a predetermined voltage. A power supply device for high-speed current reversal plating, comprising: a control device for turning on the first or second auxiliary switching element.