JPH035675B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of the Invention The present invention relates to a charging/discharging power supply device that improves the stability of discharging by efficiently and accurately charging even when the number of stages in a charging/discharging section changes.

(2) Conventional technology In general, devices for easily obtaining pulses include:
It consists of a power supply section and a charging/discharging capacitor, and pulses are obtained by charging and discharging the charging/discharging capacitor. In particular, this type of device is widely used as a device for optical excitation when obtaining laser light. By the way, lasers have recently been widely used in processing fields such as welding, cutting, and grooving. Therefore, a laser beam with irradiation energy and irradiation time suitable for each processing application is required, and as a means of achieving this, conventionally, the charging voltage and number of stages used in the charging/discharging capacitor described above are changed, and the laser beam is adjusted according to each application. It has gained. In other words, in order to obtain a laser beam with a long irradiation time, the number of stages of charge/discharge capacitors used is increased and the discharge time is lengthened, and the photoexcitation time is lengthened.To shorten the irradiation time, the number of stages of charge/discharge capacitors used is reduced. ,
All that is needed is to shorten the photoexcitation time. In this case, when the charging/discharging capacitor is discharging, charging to the charging/discharging capacitor from the power supply section is stopped.

Also, when charging, if a 50/60Hz commercial frequency is used as a charging power source, there are some that use an AC phase control circuit to feed back the charging current and charging voltage, and others that convert the commercial power source to DC. , this is a high frequency DC-DC
Some converters can perform DC charging.

(3) Problems with the conventional technology In the conventional technology described above, when the number of stages of charging/discharging capacitors used changes significantly, the charging time from the power supply section changes significantly, and charging control to deal with this changes significantly. It was extremely difficult. Therefore, the accuracy of charging deteriorates, and the stability of discharging also deteriorates, resulting in a fundamental drawback that the desired laser light cannot be obtained.

In addition, although the above-mentioned fundamental drawbacks are taken into consideration, overcurrent and overcharging are inevitable when the discharge capacitor has a large capacity or a small capacity due to the instability of the control circuit due to the feedback time delay. , it is difficult to improve charging accuracy. Furthermore, when using a DC-DC converter, the circuit becomes complicated, which is not desirable in terms of manufacturing.

(4) Purpose of the Invention The object of the present invention is to provide a charging/discharging power supply device that is easy to manufacture and can perform charging uniformly and with high precision even when the capacitance of the charging/discharging section changes, thereby obtaining a stable discharging state. be.

(5) Key Points of the Invention The present invention, when charging the charging/discharging section, performs charging in a predetermined charging cycle, sequentially detects the charging voltage in each charging cycle, compares it with a reference voltage in a comparison amplifier section, and calculates the charging voltage. The phase of energization to the charging/discharging unit in each charging cycle is controlled in accordance with the comparison signal to charge to a predetermined charging voltage. Further, when the capacity of the charging/discharging section is changed, the above object is achieved by setting the initial energization phase of the energization phase to a value corresponding to the capacity.

(6) Embodiment of the Invention Next, an embodiment of the present invention will be described with reference to FIGS. 1, 2, and 3. Note that FIG. 1 shows a configuration diagram, and FIGS. 2 and 3 show characteristic diagrams. Terminal U
and terminal V, and terminals U and W are AC power supply terminals, and between terminals U and W there is a lash current prevention coil 1, and control rectifying elements 2 and 3 (such as a thyristor) connected in parallel with reversed polarity. The primary side of the power transformer 4 is connected in series. Further, the primary side of a phase shift transformer 5 is connected between the terminals U to V. The charging cycle is determined based on the AC frequency between the terminals U to V. A rectifier circuit 6 is connected to the secondary side of the power transformer 4, and a charging/discharging capacitor 7,
8, a series circuit of resistors 9 and 10, and a discharge tube 11 for emitting discharge light are connected in parallel with each other. The charging/discharging capacitor 7 is connected to a rectifier circuit 6 via a switch _S1 . Further, near the discharge tube 11, a laser material 12 that is optically excited by receiving pulsed light from the discharge tube 11 is installed, and one half of the laser material 12 reflects the light on the optical axis of the laser material 12. A pair of resonant mirrors 13, one with a mirror surface and the other with a mirror surface, are installed so as to face each other with the laser material 12 interposed therebetween. Reference numeral 14 denotes a comparison amplifier circuit that compares a predetermined reference voltage with a charging voltage.The common connection portion of the resistors 9 and 10 is connected to the negative side input terminal of this comparison amplifier circuit 14, and to the positive side terminal. A sliding portion of a reference voltage adjusting resistor 17 applied from a DC power supply 15 via a resistor 16 is connected. Further, an adjusting resistor 17 is connected to both ends of this reference voltage adjusting resistor 17.
A switch S ₂ is connected which short-circuits the applied voltage of. The output side of the comparison amplifier circuit 14 is connected to the base side of a transistor 18 that controls current according to the signal of the comparison amplifier circuit 14.

On the other hand, a phase shifting capacitor 19 is connected to one end of the secondary side of the phase shifting transformer 5, and diodes 20, 21, 22, 23 are connected between this output side and the other end of the secondary side of the phase shifting transformer 5. The input terminal of a bridge rectifier circuit formed by is connected.

Furthermore, one end of the output side of this bridge rectifier circuit is connected to the collector side of the transistor 18 via a resistor 24, and the other end is connected to the emitter side. Note that a resistor 25 is connected in parallel to the resistor 24 via a switch _S3 , and the switch _S3 and the switch _S1 are interlocked. Further, a gate pulse generation circuit 26 that outputs a gate pulse based on a voltage difference between the middle point of the secondary side of the phase shifting transformer 5 and the output side of the phase shifting capacitor 19 is connected to the secondary side of the phase shifting transformer 5. It is connected to the middle point of the side and the output side of the phase shifting capacitor 19. The control rectifying elements 2 and 3 are operated by the output of the gate pulse generating circuit 26.

Reference numeral 27 denotes a clock oscillation circuit for starting discharge of the flash lamp 11. A switching circuit 28 for opening and closing the switch _S2 is connected to this clock oscillation circuit 27. A trigger circuit 30 for providing a starting trigger to the flash lamp 11 is connected via a trigger electrode 29 wound externally to the flash lamp 11 .

Next, the apparatus configured as above will be explained. First, when generating a pulse waveform with a wide pulse width, the switches _S1 and _S2 are closed. When charging is performed in this state, no clock signal is output from the clock oscillation circuit 27,
Switch _S2 is therefore in the open state. And when alternating current is applied between terminal UV and terminal UW,
A reference voltage set by the DC power supply 15 is input to the positive side end of the comparison amplifier circuit 14 .
Therefore, a positive signal is outputted from the comparison amplifier circuit 14, and the transistor 18 is completely turned on. That is, a closed circuit is formed in the secondary side circuit of the phase shift transformer 5 through the transistor 18, and a signal based mainly on the time constant of the capacitance of the phase shift capacitor 19 and the parallel resistance of the resistors 24 and 25 is generated. This occurs between the middle point of the secondary side of the phase shift transformer 5 and the output side of the phase shift capacitor 19. A signal between these two points is input to the gate pulse generation circuit 26. This gate pulse generation circuit 26 is connected to the second
The control rectifying elements 2 and 3 are controlled at a conduction angle of θ ₁ shown in the figure. As described above, in one cycle, the primary side or the secondary side of the power transformer 4 is connected to the secondary side.
A voltage waveform like a in the figure or a current shaping like b in the figure can be obtained. Note that the sine wave UW is a power waveform between terminals U and W. The voltage or current thus obtained is full-wave rectified by the rectifier circuit 6 on the secondary side of the phase shift transformer 4, and charged into the charging/discharging capacitors 7, 8. The voltage charged in the above manner is fed back to the negative end of the comparison amplifier circuit 14 from the connection point between the resistors 9 and 10, and is compared with the reference voltage at the positive end in the same manner as described above. At this time, the difference between the negative end voltage and the positive end voltage is smaller than that during the charging cycle. Therefore, comparison amplifier circuit 1
The output of 4 decreases and the transistor 18 decreases its collector current. Therefore, the time constant on the secondary side of the phase shift transformer 5 is mainly determined by the phase shift capacitor 9, the parallel resistance of the resistors 24 and 25, and the resistance caused by the decrease in the collector current of the transistor 18. , the input to the gate pulse generation circuit 26 is delayed. The conduction angle of the controlled rectifying elements 2, 3 therefore decreases. In other words, the amount of charge to the charge/discharge capacitors 7, 8 decreases. Charging to a predetermined voltage is performed by repeating the above-described actions. Note that this repetition period is caused by the AC power frequency between the terminals U to V. The charging voltage and charging current of this repeated process are shown by the solid line V ₁ and the solid lines I _1-1 to I _1-4 in FIG. 3. Incidentally _{, Vc} represents _a predetermined _voltage , and _{t1 to t6} represent time, and _the control rectifying element ₂ , This corresponds to one cycle time of conduction of 3. Further, the vertical axis I indicates the charging current, and P indicates the discharging current. The reason why the peak values of the currents I _1-1 to _{I 1-4} in each charging cycle are different is because the current of the transistor 18 decreases as charging progresses. This is because the amount of charge in the charging and discharging capacitors 7 and 8 increases successively in each cycle, and the conduction angle θ ₁ becomes smaller.

When the charging and discharging capacitors 7 and 8 reach the predetermined charging voltage V _c as described above, the resistors 9 and
A voltage corresponding to the reference voltage set by the DC power supply 15 is inputted to the negative end of the comparison amplifier circuit 14 from the connection point 10 . The output of the comparison amplifier circuit 14 becomes 0 or negative, turning off the transistor 18. Therefore, the secondary side circuit of the phase shift transformer 5 is opened, and the gate pulse generating circuit 26 does not output a gate pulse at the forward bias timing of the control rectifiers 2, 3, does not ignite, and charging to the charging/discharging capacitors 7 and 8 is stopped.
When irradiating the laser beam, the clock oscillation circuit 27 outputs a clock, the switching circuit 28 closes the switch _S2 , the trigger circuit 30 issues a starting trigger, and the charging/discharging capacitor 7 , 8 is discharged to the flash lamp 11. Solid line in Figure 3
P ₁ indicates the discharge current waveform, and T ₁ indicates the time.
The discharge of the flash lamp 11 generates pulsed light with a wide pulse width, and the laser substance 12 is excited by this pulsed light to emit laser light with a long irradiation time.

Next, when generating a pulse waveform with a narrow pulse width, the switches _S1 and _S3 are opened. Therefore, the charging/discharging capacitor 7 and the resistor 25
is separated from the circuit system. In this state, the same effect as in the case of generating the wide pulse waveform described above is performed. As a result, first, a positive signal is output to the output of the comparison amplifier circuit 14. This signal is a signal that turns transistor 18 completely on. Therefore, the secondary side circuit of the phase shift transformer 5 is closed and mainly consists of the capacitance of the phase shift capacitor 19 and the resistor 2.
A signal based on the time constant of 4 is transmitted to the phase shift transformer 5.
occurs between the midpoint of the secondary side of and the output side of the phase shift capacitor 19. The signal between these two points is then input to the gate pulse generation circuit 26. Therefore, this gate pulse generating circuit 26 controls the control rectifying elements 2 and 3 at a conduction angle of θ ₂ shown in FIG. Here, θ ₁
>θ ₂ because the time constant of the secondary circuit of the phase shift transformer 5 can be changed depending on the value of the resistor 24 alone with respect to the value of the parallel connection of the resistors 24 and 25. When 24 is used alone, the time constant is longer, the rise of the input signal to the gate pulse generation circuit 26 is delayed, and the gate pulse signal from the gate pulse generation circuit 26 makes the control rectifiers 2 and 3 conductive. This is because the sending of the data is delayed. However, in this one cycle action, a voltage waveform as shown in c or a current waveform as shown in d in FIG. 2 is obtained on the primary or secondary side of the power transformer 4. These voltages or currents are full-wave rectified by the rectifier circuit 6 and charged to the charge/discharge capacitor 8. Then, in the next charging cycle, this charging voltage is fed back from the connection point of the resistors 9 and 10 to the negative end of the comparison amplifier circuit 14, and compared with the reference voltage at the positive end, and a positive output is generated according to the difference. input to the transistor 18; As a result, the current flowing through transistor 18 is reduced compared to the previous charging cycle. In other words, the resistance of transistor 18 increases. Therefore, the time constant of the secondary circuit of the phase shift transformer 5 becomes longer, and as a result, the conduction angle θ ₂ of the controlled rectifying elements 2 and 3 is reduced. By repeating the above charging cycle, the charging/discharging capacitor 7 is charged. The charging voltage waveform and charging current are shown by the dotted lines in Figure 3.
V ₂ and dotted lines I _2-1 to _{I 2-4} . As described above, the charging and discharging capacitor 8 is charged to a predetermined charging voltage.
When V _c is reached, charging is stopped in the same way as when obtaining the wide pulse described above. Laser light with a short pulse width is generated by the same action as the laser light irradiation described above. At this time, the current waveform discharged to the flash lamp 11 is shown by the dotted line in FIG.
Shown on P ₂ .

As described above, each charging voltage is sequentially fed back in each cycle, and the charging phase in each cycle is changed.
By controlling the charging current, accurate charging can be performed within a predetermined time even if the capacitance of the charging/discharging capacitor changes. In the above embodiment, the charging cycle is determined based on the AC power frequency, but a charging cycle may be set separately depending on the situation.

Further, the present invention is not limited to the above-described embodiments, and unless it deviates from the gist, the present invention can be applied to a single-phase power supply,
It goes without saying that either a three-phase or multi-phase power source may be used, and it can also be applied to devices that require various pulse outputs.

(7) Effects of the Invention According to the present invention, in a pulse output generation device composed of a power source section and a charging/discharging section, the charging cycle can be made uniform in response to changes in charging/discharging capacity that are performed to obtain a desired pulse output. Any capacity can be handled by controlling the amount of charge in each cycle. In other words, there is no need to consider overcharging to a specified voltage or higher in a short period of time when the capacity is small, or long-term charging or excessive current in the charging circuit when the capacity is large. Charging voltage accuracy can be maintained regardless of capacitance changes using a normal commercial power source without using a special power source. Therefore, in devices that require various pulse outputs, it is possible to obtain the optimum pulse output, and the pulse output can also be easily obtained with good quality. Particularly in processing using laser light (for example, welding, etc.), it is possible to provide the optimum laser light and easily improve the processing accuracy. In other words, it is possible to provide a charging/discharging power supply device that can easily realize a device that fully satisfies the accuracy required for various pulses.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of an embodiment related to the present invention;
The figure shows the charging current waveform, charging voltage waveform, and conduction angle of the control rectifier in one cycle in Figure 1, and Figure 3 shows the charging process waveform of the charging current and charging voltage up to a predetermined voltage in Figure 1. FIG. 3 is a diagram showing current waveforms of discharge and discharge, respectively. 2, 3... Control rectifier, 5... Phase shift transformer, 7, 8... Charge/discharge capacitor, 19... Phase shift capacitor, 26... Gate pulse generation circuit.

Claims (1)

[Claims] 1 A means for determining a charging cycle, a control rectifier that energizes and outputs an AC power signal in a controlled energization phase within one cycle of the charge cycle determined by the means, and a energization output of the control rectifier. A plurality of charging/discharging sections each having a means for varying the number of stages used, and charging voltages of these charging/discharging sections are sequentially compared with a predetermined reference voltage in each charging cycle, and a signal corresponding to the difference is output. a comparison section, a phase control section that controls the energization phase of the control rectification section in response to a signal from the comparison section, and an initial phase control output of the phase control section that is determined in response to a means for varying the number of stages used in the charging/discharging section. and a means for starting charging of the charging/discharging section at an initial energization phase determined by the means, and charging according to a phase control output of each charging cycle of the phase control section to reach a predetermined charging voltage. Then, the charging/discharging power supply device stops charging and discharges to the discharge body.