JP2001245473A - Power source device and optical fiber fusion connection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power source device high in quality. SOLUTION: In the power source device wherein a multi-stage voltage doubler rectifying circuit connected to the secondary winding of a step-up transformer stepping up alternating voltage by switching semiconductor element connected to the primary winding side of the step-up transformer and switching of the switching semiconductor element is mounted on one face of a printed circuit board and a current detection circuit is mounted on the other face, a conductive film is provided between the multi-stage voltage doubler rectifying circuit and the current detection circuit, and connected to the connection point of the multi- stage voltage doubler rectifying circuit and the current detection circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high voltage generator suitable for use as an optical fiber fusion splicing power supply for supplying electric power for fusion splicing optical fibers by heat generated by arc discharge.

[0002]

2. Description of the Related Art As a conventional power supply for optical fiber fusion splicing, a voltage waveform proportional to an average value of a load current is disclosed as disclosed in Japanese Patent Publication No. 3-32305, in particular, FIG. Some include a detection circuit that can detect accurately. Regardless of the conventional example and the level of the voltage, in order to accurately control the load power in proportion to the current flowing through the main circuit of the power supply, it is necessary to accurately perform the current detection. The circuit design that can be done is done.

[0003]

[Problems to be solved by the invention]
In the power supply device as disclosed in Japanese Patent No. 32305, since high-density is strongly required, mounting of a high-density electronic component is performed while including a high-voltage generation device. A stray capacitance that cannot be ignored is formed between the low-voltage main circuit line and the current detecting circuit located on the low-voltage side, and even a current flowing through the stray capacitance is detected. Therefore, the current detection value often becomes larger than the load current or the input current flowing through the actual main circuit line and the actual current detection line, and accurate power control is sometimes difficult.

In the case of a power supply for generating a high voltage such as a normal Cockcroft-Walton circuit, if the current detecting circuit is at a low potential, the high voltage generating section, the low voltage main circuit line and the low voltage side There is a case where a stray capacitance that cannot be ignored is formed between the current detection circuit and the current detection circuit located in the area. In this case, the current flowing through the stray capacitance is also detected. The current cannot be ignored.

Accordingly, an object of the present invention is to provide a high-quality power supply device that can be reduced in size.

[0006]

[Means for Solving the Problems]

According to a first aspect of the present invention, there is provided a switching semiconductor device connected to a primary winding of a step-up transformer and a multi-stage voltage doubler connected to a secondary winding of the step-up transformer. A power supply device having a rectifier circuit mounted on one surface of a printed circuit board and a current detection circuit mounted on the other surface, wherein a conductive film is provided between the multi-stage voltage doubler rectifier circuit and the current detection circuit. Wherein the conductive film is connected to a connection point between one input terminal of the multi-stage voltage doubler rectifier circuit and the current detection circuit.

According to a second aspect of the present invention, there is provided a power supply device according to the first aspect, wherein the conductive film is formed on any one surface or inside the printed circuit board. I will provide a.

According to a third aspect of the present invention, in order to solve the above-mentioned problem, in the first or second aspect, the multi-stage voltage doubler rectifier is embedded in an electrically insulating resin, and the conductive film is A power supply, wherein a terminal pin connected to a connection point between a multi-stage voltage doubler rectifier circuit and the current detection circuit protrudes from the electrical insulating resin, and a hole through which the terminal pin is inserted is formed in the conductive film. Provide equipment.

According to a fourth aspect of the present invention, in order to solve the above-mentioned problems, a multi-stage voltage doubler rectifying unit including a step-up transformer for stepping up an AC voltage, a plurality of capacitors and a plurality of diodes, and a high-voltage capacitor are provided on a circuit board. In a high-voltage power supply device mounted on one surface, a relatively large cut is provided in a surface area of the circuit board corresponding to the position of the step-up transformer, and the plurality of multi-stage voltage doubler rectifier circuits are provided. Provided is a power supply device, wherein an elongated slit is formed in a surface area between the circuit board on which a capacitor and the high-voltage capacitor are mounted.

According to a fifth aspect of the present invention, in order to solve the above problem, in the fourth aspect, the circuit board is disposed so as to cover the open surface of a case having an open surface made of an electrically insulating material. The circuit board is provided with a notch forming a gap between the circuit board and the side wall of the case in addition to the relatively large cut.

According to a sixth aspect of the present invention, there is provided an optical fiber fusion apparatus including a discharge electrode supplied from the power supply device according to any one of the first to fifth aspects. An incoming connection device is provided.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a circuit example according to a power supply device of the present invention will be described with reference to FIG. 1 is a DC power supply circuit having a voltage adjusting function, 2 is a control circuit 2A, switching semiconductor elements 2B and 2C such as transistors operated at a high frequency by the control circuit 2A, and a primary winding 2Da.
A high frequency inverter comprising a step-up transformer 2D having a secondary winding 2Db and the like; and 3, a normal multi-stage voltage doubler such as a Cockcroft-Walton circuit or a Schunkel circuit in which a plurality of circuits each comprising a capacitor and a diode are connected in cascade. A rectifier circuit 5 is charged to a DC high voltage through a high voltage resistor 4 connected to an output terminal of the multistage voltage doubler rectifier circuit, and a high voltage capacitor for passing an AC voltage, 6 is a current limiting resistor, and 7 is a current limiting resistor. A pair of discharge electrodes 9 of the optical fiber fusion splicer, a current detection circuit which is connected in the middle of the main circuit line 8 which is always at a low potential and detects a current flowing through the discharge electrode 7, and 10 is an important component of the present invention The multi-stage voltage rectifier is disposed between the multi-stage voltage doubler rectifier circuit 3 and a part of the main circuit line 8 which is always at a low potential and the current detection circuit 9. It is connected to a connection point X between the one input terminal 3A and the current detection circuit 9 of the road 3.

Next, the arrangement and configuration of the power supply device according to the present invention will be described with reference to FIGS. As shown in FIG. 2, this power supply device has a single printed circuit board 20.
And a booster transformer 2D of the high-frequency inverter 2, a multi-stage voltage doubler rectifier circuit 3, a high voltage resistor 4, a high voltage capacitor 5, and a current limiting resistor 6 on one surface of the printed circuit board 20. Are mounted in an electrical insulating resin such as an epoxy resin, and various electronic components such as the DC power supply circuit 1 are mounted.

As shown in FIG. 3, a wiring pattern 8 A and a wiring pattern 8 which constitute a main circuit line 8 which is always at a low potential
A current detection circuit 9 composed of a surface mount component mounted on A and the like and a control circuit of a primary circuit are formed or mounted on the other surface of the printed circuit board 20. An output terminal 21A is electrically connected to one of the discharge electrodes. A voltage that increases toward a predetermined high voltage value until a spark discharge occurs between the discharge electrodes 7 is output to the output terminal 21A. After the occurrence of the spark discharge, a low-frequency high-frequency AC voltage appears.

Next, FIG. 4 shows a state of the upper surface of the printed circuit board 20 before the high-voltage module 21 is mounted. When the high-voltage module 21 is mounted, a relatively high voltage portion of the multistage voltage doubler rectifier circuit 3 is provided. The conductive film 10 is formed on the mounting surface of the high-voltage module 21 on the printed circuit board 20 so as to cover the surface area where is located or a wider area. The thickness of the conductive film 10 may be arbitrary. The conductive film 10 may be formed in an inner layer of the printed circuit board 20. A hole 10A is formed in the conductive film 10, and the hole 10A allows a terminal pin corresponding to one input terminal of the multi-stage voltage doubler rectifier circuit 3 extending from the high voltage module 21 to pass therethrough. Wiring pattern 8A constituting main circuit line 8 always at a low potential
And soldered.

Therefore, according to this arrangement and configuration, the printed circuit board 20 is formed on the surface area of the printed circuit board 20 corresponding to at least the high voltage portion of the high voltage module 21, in other words, at least the high voltage portion of the multistage voltage doubler rectifier circuit 3, and on the opposite surface. A conductive film 10 exists between the wiring pattern 8A constituting the main circuit line 8 and the current detecting circuit 9, and the conductive film 10 is connected to one input terminal 3A of the multi-stage voltage doubler rectifier circuit 3 and the current detecting circuit 9. 9, the stray capacitance is formed between the high voltage portion of the multi-stage voltage doubler rectifier circuit 3 and the conductive film 10 unlike the conventional device. The current flowing through the stray capacitance flows to the connection point X and the secondary winding 2Db of the step-up transformer 2D via the conductive film 10, and does not flow to the current detection circuit 9. Therefore, the current detection circuit 9 can accurately detect the load current, which enables accurate control of the inverter 2 and the DC power supply circuit 1,
A highly reliable power supply device can be provided without reducing the mounting density of electronic components.

Next, the high voltage module 21 will be described with reference to FIGS. On one surface of the circuit board 30, a step-up transformer 2D, a plurality of diodes and a plurality of capacitors constituting a multi-stage voltage doubler rectifier circuit 3, a high voltage resistor 4, a high voltage capacitor 5, and a current limiting resistor 6 are mounted. ing. The circuit board 30 has a relatively large notch 31 at a place where the step-up transformer 2D is mounted, and a plurality of T at a place located between the capacitor on the smoothing column side and the capacitor on the push-up column of the multi-stage voltage doubler rectifier circuit 3. A first slit 32 having a shape in which the characters are reversed and connected in series is formed, and a second slit 33 is formed at a position located between the multi-stage voltage doubler rectifier circuit 3 and the high-voltage capacitor 5.

Further, the circuit board 30 has elongated notches 34 and 35 along the longitudinal direction on both sides thereof, and an elongated notch 36 extending at right angles from the longitudinal direction near both lead terminals of the current limiting resistor 6. , 37, 38
And a relatively large cut 39 extending to form a gap between both lead terminals of the current limiting resistor 6.

Here, the relatively large cut 31 is used when the case 21B made of an electrically insulating material is combined with the circuit board 30 and then the electric insulating resin 43 is poured into the case 21B as shown in FIG. Notch 31
, The electric insulating resin 43 is poured. In the high-voltage module 21, the step-up transformer 2 has the most complicated shape, and the injection of the electric insulating resin 43 into the case 21B from the position where the step-up transformer 2 is located occurs due to the step-up transformer 2 shape. The number of voids can be minimized. The first slit 32 is provided in the multi-stage voltage doubler rectifier circuit 3.
The purpose of this is to increase the electrical insulation between adjacent ones of the capacitor and the diode that constitute the above. Second
The slits 33 are for increasing the electrical insulation between the high-voltage capacitor 5 and the capacitors and diodes constituting the multi-stage voltage doubler rectifier circuit 3.

Next, when the circuit board 30 is combined with the case 21B with the component mounting surface inside the case as shown in FIGS. 6 and 7, the elongated cutouts 34 and 35 along the longitudinal direction are formed in the case 21B. An elongate gap is formed between the side wall and the side wall to serve to discharge air from the case 21B when pouring the electrically insulating resin into the case 21B. The elongated notch 36 is used to increase electrical insulation between the high voltage terminal of the high voltage resistor 4 and the terminal of the current limiting resistor 6 on the discharge electrode 7 side. The elongated slit 37 is a terminal of the current limiting resistor 6 on the discharge electrode 7 side and the fixing pin 4 connected to the ground potential.
This is for increasing the electrical insulation between 0. Also,
The elongated notch 38 is for increasing the electrical insulation between the other terminal of the current limiting resistor 6 and the fixing pin 41 connected to the ground potential. Further, the cut 39 not only enhances the electrical insulation between both the lead wires of the current limiting resistor 6, but also the electric insulating resin 43 may be poured from the cut 39 as needed.

The cuts and slits described above in addition to the elongated cutouts 34 and 35 serve to discharge air from the case 21B when an electric insulating resin 43 described later is poured into the case 21B. Air can be prevented from remaining between the circuit board 30 and
A small and high-quality high-voltage module can be obtained in addition to the function of enhancing their electrical insulation.
The electric insulating resin 43 is connected to the circuit board 3 as shown in FIG.
The wiring pattern and the solder film formed on the back surface of the case 21 are buried and injected until the opening surface of the case 21B becomes almost the same level as or slightly lower than the end of the case opening.

The terminal pins 42 are inserted into the through holes 10 A of the conductive film 10 when the high-voltage module 21 is mounted on the printed circuit board 20 as shown in FIG. Connected to point X in FIG. 1 and soldered.

Such a power supply is small and of high quality, so that it can be used in various devices. In particular, when the power supply is used as a power supply of an optical fiber fusion splicing apparatus using a storage battery as a DC power supply, the effect is small. Is big. The circuit on the primary side of the step-up transformer is not limited to the embodiment, and various circuits such as a chopper circuit may be employed depending on the load, instead of the high frequency inverter.

[0025]

As described above, according to the present invention, even in a power supply device employing a high-voltage module having a relatively high mounting density, a high-voltage portion of the multistage voltage doubler rectifier circuit and another Since the current flowing through the load can be accurately detected without substantially detecting the current flowing through the stray capacitance formed between the low-voltage circuit portion, power control can be performed accurately, and a high-quality power supply can be performed. A device can be obtained.
In addition, various cuts in the circuit board of the high-voltage module,
The provision of the slits and the notches makes it possible to provide a power supply device of higher quality, which ensures electrical insulation without lowering the mounting density.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining one embodiment of a power supply device of the present invention.

FIG. 2 is a diagram for explaining an embodiment of the power supply device of the present invention.

FIG. 3 is a partial cross-sectional view for explaining an embodiment of the power supply device of the present invention.

FIG. 4 is a diagram for explaining an embodiment of the power supply device of the present invention.

FIG. 5 is a diagram for explaining another embodiment of the power supply device of the present invention.

FIG. 6 is a diagram for explaining another embodiment of the power supply device of the present invention.

FIG. 7 is a diagram for explaining another embodiment of the power supply device of the present invention.

FIG. 8 is a diagram for explaining another embodiment of the power supply device of the present invention.

[Explanation of symbols]

1. DC power supply circuit 2. High frequency inverter 3. Multistage voltage doubler rectifier circuit 4. High voltage resistor 5. High voltage capacitor 6. Current limiting resistor 7. Discharge electrode 8. Constant low potential Main circuit line 9, Current detection circuit 10, Conductive film 20, Printed circuit board 21, High voltage module 30, Circuit board 31, Relatively large cut 32, 33, Slit 34, 35
・ Cut 36,37,38,39 ・ ・ Cut 40,41 ・ ・ Fixing pin 42 ・ ・ Terminal pin 43 ・ ・ Electrical insulating resin

Claims (6)

[Claims] A switching semiconductor element connected to a primary winding side of the step-up transformer;
A power supply device having a multi-stage voltage doubler rectifier circuit connected to the next winding mounted on one surface of a printed circuit board and a current detection circuit mounted on the other surface, wherein the multi-stage voltage doubler rectifier circuit and A power supply device, comprising: a conductive film between the current detection circuit and the conductive film connected to a connection point between one input terminal of the multi-stage voltage doubler rectifier circuit and the current detection circuit. 2. The power supply device according to claim 1, wherein the conductive film is formed on one surface or inside the printed circuit board. 3. The multi-stage voltage doubler rectifier circuit according to claim 1, wherein the multistage voltage doubler rectifier circuit is embedded in an electrically insulating resin, and the conductive film is connected to the multistage voltage doubler rectifier circuit and the current detection circuit. A power supply device, wherein a terminal pin connected to a connection point protrudes from the electric insulating resin, and a hole through which the terminal pin is inserted is formed in the conductive film. 4. A multi-stage voltage doubler rectifier circuit comprising a step-up transformer for boosting an AC voltage, a plurality of capacitors and a plurality of diodes, and a high voltage capacitor mounted on one surface of a circuit board. In the power supply device, a relatively large cut is provided in a surface area of the circuit board corresponding to a position of the step-up transformer, and the plurality of capacitors of the multi-stage voltage doubler rectifier circuit and the high voltage capacitor are mounted. A power supply device, wherein an elongated slit is formed in a surface area between circuit boards. 5. The circuit board according to claim 4, wherein the circuit board is arranged so as to cover the open face of a case having an open face made of an electrically insulating material. A power supply unit provided with a notch that forms a gap between the case and the side wall of the case. 6. An optical fiber fusion splicing device comprising a discharge electrode supplied from the power supply device according to claim 1. Description: