JPH11346477A - Inverter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance noise resistance by improving the impedance frequency characteristics of a filter capacitor plus a pattern and eliminating the adverse effects of the pattern. SOLUTION: A filter capacitor 8, disposed between the output terminal of a rectifier circuit 1 and a frame ground, is mounted in the vicinity of the output terminal of the rectifying circuit 1. The filter capacitor 8 has one terminal wired, through the shortest route, to the output of the rectifying circuit 1 and the other terminal wired, through a shortest route, to a land 14 on a printed board 4 arranged in the vicinity of the output terminal of the rectifier circuit 1. A conductive stud 10 is provided between the land 14 and a heat sink 3 and screwed to the land 14 on the printed board 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter device for reducing common mode noise and normal mode noise superimposed on a power supply line and improving noise immunity.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to the drawings. FIG.
Is a pattern diagram of a filter capacitor, and FIG. 6 is a circuit diagram of an inverter device. 1 is a rectifier circuit, 2 is an inverter circuit, 3 is a heat sink, 5, 6, 7, and 8 are filter capacitors, and 9 is a smoothing capacitor. 11 is an AC power supply, 12 is a motor, 15 is a pattern, and 16 is a power supply line. As shown in FIG. 5, common mode noise and normal mode noise superimposed on the power supply line 16 are supplied between the power supply input terminal block (or connector) 13 and the frame ground FG, and the filter capacitors 5 and 6 and the rectifier circuit 1 The filter capacitors 7 and 8 provided between the output and the frame ground FG respectively bypass the frame ground FG. In FIG. 6, the heat sink 3 also serves as the frame ground FG.

[0003]

However, according to the prior art, one terminal of the filter capacitor is connected to the output of the rectifying element in a pattern of a printed circuit board, and the other terminal is also connected to the pattern 15. Connected to frame ground FG. When the pattern 15 is long, the inductance of the pattern 15 connected to the filter capacitor becomes large, and (filter capacitor + pattern) (that is, the filter capacitor provided between the power input terminal block 13 and the frame ground FG + one terminal of the filter capacitor) From the pattern connected to the power input terminal block 13 + the pattern connected from the other terminal of the filter capacitor to the frame ground, or from the output of the rectifier circuit 1 and the filter capacitor provided between the frame ground FG and one terminal of the filter capacitor The impedance frequency characteristic of the pattern connected to the output of the rectifier circuit 1 + the pattern connected from the other terminal of the filter capacitor to the frame ground FG) is deteriorated. When a noise current flows through the pattern, radiation noise is generated. However, when the pattern is long, the control board facing the pattern connected to the filter capacitor is adversely affected. That is, malfunction of the IC on the control board is caused, and when approaching the signal line on the same printed board, malfunction of the IC connected to the signal line is caused by interference. The same applies to the case where the pattern routing is poor. As described above, depending on the mounting position of the filter capacitor, there is a problem that the effect of the filter capacitor is not obtained and the noise immunity is not improved. Therefore, the present invention improves the impedance frequency characteristic of (filter capacitor + pattern) and eliminates the adverse effect of the pattern.
An object is to improve noise immunity.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a rectifier circuit for converting an AC power supply voltage to a DC voltage, a smoothing capacitor for smoothing the rectified pulsating voltage, and a DC voltage converter for converting the DC voltage to an AC voltage. An inverter circuit for converting the
A printed circuit board on which the rectifier circuit, the smoothing capacitor, and the inverter circuit are mounted, a heat sink that is installed to face the printed circuit board and cools the power elements of the rectifier circuit and the inverter circuit, and a frame ground for grounding the heat sink. In the inverter device, a filter capacitor provided between the output terminal of the rectifier circuit and the frame ground is mounted near the output terminal of the rectifier circuit, and one terminal of the filter capacitor is formed by a pattern on the printed circuit board. The other end of the filter capacitor is shortest-wired to a land on the printed circuit board provided near the output terminal of the rectifier circuit, and a conductive wire is provided between the land and the heat sink. Studs, and the studs are And a filter capacitor provided between the input terminal of the rectifier circuit and the frame ground is mounted near a power supply input terminal, and One terminal is shortest-wired to the power input terminal in a pattern of a printed circuit board, and the other terminal of the filter capacitor is shortest-wired to a land on the printed circuit board provided in the vicinity thereof, between the land and the heat sink. A conductive stud is provided, and the stud is screwed to a land on the heat sink and the printed circuit board.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing a mounting state of a filter capacitor provided between an output of a rectifier circuit and a frame ground, and FIG. 2 is a pattern diagram showing a mounting state of a filter capacitor provided between an output of the rectifier circuit and a frame ground. The description of the same reference numerals as in FIGS. 5 and 6 for describing the conventional apparatus is omitted. 4 is a printed circuit board, 10 is a stud, and 14 is a land. Filter capacitor 7,
8 is mounted near the rectifier circuit 1 mounted on the printed circuit board 4, one of the terminals of the filter capacitors 7 and 8 is shortest-wired to the output terminal of the rectifier circuit 1 in the pattern of the printed circuit board 4, and The other terminals 7 and 8 are connected to the lands 14 on the printed circuit board 4 in the shortest route in the vicinity of the output terminal of the rectifier circuit 1. By performing the shortest wiring (connecting the terminals with a straight line), the wiring inductance is reduced, and the characteristics of the filter capacitors 7 and 8 are improved. A conductive stud 10 is provided between the land 14 and the heat sink 3, and the stud 10 is screwed (not shown) to the heat sink 3 and the land 14 of the printed circuit board 4. By providing the land 14 and screwing it to the stud 10 with a screw, attachment to the printed circuit board is simplified. In addition, since the land 14 is in surface contact with the screw, the impedance at the contact surface is reduced, and the noise current is easily circulated to the stud 10. Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a side sectional view showing a mounting state of a filter capacitor provided between the power input terminal block and the frame ground, and FIG. 4 is a pattern diagram showing a mounting state of a filter capacitor provided between the power input terminal block and the frame ground. . 3 and 4, the filter capacitors 5 and 6 are mounted near the power input terminal block 13 mounted on the printed circuit board 4, and the filter capacitors 5 and 6 are mounted.
6 is shortest-wired to the power input terminals R and S of the power input terminal block 13 in the pattern of the printed circuit board 4;
The other terminals of the filter capacitors 5 and 6 are located near the power input terminal block 13 and on the land 1 on the printed circuit board 4.
4 shortest wiring. The shortest wiring reduces the wiring inductance and improves the characteristics of the filter capacitors 5 and 6. The effects of the lands 14 and the studs 10 are the same as those of the first embodiment of the present invention.

[0006]

As described above, according to the present invention, it is possible to provide an inverter device capable of effectively bypassing noise, improving noise immunity, and improving reliability.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a mounted state of a filter capacitor provided between an output of a rectifier circuit and a frame ground.

FIG. 2 is a pattern diagram showing a mounting state of a filter capacitor provided between an output of a rectifier circuit and a frame ground.

FIG. 3 is a side sectional view showing a mounted state of a filter capacitor provided between a power input terminal block and a frame ground.

FIG. 4 is a pattern diagram showing a mounting state of a filter capacitor provided between a power input terminal block and a frame ground.

FIG. 5 is a pattern diagram of a filter capacitor.

FIG. 6 is a circuit diagram of an inverter device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 rectifier circuit 2 inverter circuit 3 heat sink 4 printed circuit board 5, 6 filter capacitor provided between power input terminal block and frame ground 7, 8 filter capacitor provided between rectifier circuit output and frame ground 9 smoothing capacitor 10 stud 11 AC power supply 12 Motor 13 Power input terminal block 14 Land 15 Pattern 16 Power line

Claims (2)

[Claims] A rectifier circuit for converting an AC power supply voltage to a DC voltage; a smoothing capacitor for smoothing the rectified pulsating voltage; an inverter circuit for converting the DC voltage to an AC voltage;
A printed circuit board on which the rectifier circuit, the smoothing capacitor, and the inverter circuit are mounted, a heat sink that is installed to face the printed circuit board and cools the power elements of the rectifier circuit and the inverter circuit, and a frame ground for grounding the heat sink. In the inverter device, a filter capacitor provided between the output terminal of the rectifier circuit and the frame ground is mounted near the output terminal of the rectifier circuit, and one terminal of the filter capacitor is formed by a pattern on the printed circuit board. The other end of the filter capacitor is shortest-wired to a land on the printed circuit board provided near the output terminal of the rectifier circuit, and a conductive wire is provided between the land and the heat sink. Studs, and the studs are Inverter apparatus characterized by being screwed to click and lands on the printed circuit board. 2. A rectifier circuit for converting an AC power supply voltage to a DC voltage, a smoothing capacitor for smoothing the rectified pulsating voltage, an inverter circuit for converting the DC voltage to an AC voltage,
A printed circuit board on which the rectifier circuit, the smoothing capacitor, and the inverter circuit are mounted, a heat sink that is installed to face the printed circuit board and cools the power elements of the rectifier circuit and the inverter circuit, and a frame ground for grounding the heat sink. In the inverter device, a filter capacitor provided between the input terminal of the rectifier circuit and the frame ground is mounted near a power input terminal, and one terminal of the filter capacitor is connected to the power input terminal in a printed circuit board pattern. The other terminal of the filter capacitor is shortest wired to a land on the printed circuit board provided in the vicinity thereof, and a conductive stud is provided between the land and the heat sink. Land on the printed circuit board Inverter apparatus characterized by being screwed.