JPH09147994A - Power supply plug for electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce influence of magnetic leakage noise on an electronic apparatus main body by arranging a higher harmonic current suppressing reactor part, which electrically connects a plug member arranged in a resin casing and a power supply wire terminal together, between the plug member and the power supply wire terminal. SOLUTION: A casing of a power supply plug for an electronic apparatus is composed of a case 1 made of resin such as phenol resin and a lid 3. In the lid 3, mounting holes 301 for a reactor part 2, power supply wire terminals 302 to which a power supply code 5 from the electronic apparatus is connected, and metallic plug members 4 to be inserted into insertion holes in a plug socket and the like are installed. In the reactor part 2, mounting metal fittings 204 stuck on the reactor part 2 are mounted to the mounting holes 301 in the lid 3 by means of screws 6, and a lead-out wire 206 is connected to one plug members 4, while a lead-out wire 205 is connected to one power supply wire terminals 302. The other power source wire terminals 302 is directly connected to the other plug parts 4. In this way, influence of magnetic noise, which may be generated from the reactor part 2 suppressing higher harmonics, on the electronic apparatus main body can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power plug for supplying commercial AC power to electronic devices such as personal computers and television receivers.

[0002]

2. Description of the Related Art In recent years, in electronic equipment such as personal computers and television receivers, commercial AC power supplies (10
0V, 50 / 60Hz, etc.) is used as input power, and a DC voltage is obtained by smoothing with a rectifying element or a capacitor inside the main body of the electronic device, and further, by performing pulse width control, etc. And the method of obtaining electric current is the mainstream. Generally, a method of converting an AC voltage into a DC voltage with a rectifying element or a capacitor is called a capacitor input method, and then a method of performing a pulse width control on the rectified DC voltage to obtain a predetermined DC voltage is called a PWM converter method. .

With the widespread use of such electronic devices, problems such as distortion of the power supply voltage and damage to the power devices have recently been increasing. One of the causes is the electronic device adopting the above-mentioned capacitor input method.

In the capacitor input method, when the AC voltage is converted into the DC voltage, the capacitor performs a rapid charging / discharging operation, so that a current having a steep peak as shown in FIG. 7 flows in the AC input line. When the electric current as shown in FIG. 7 flows to many electronic devices all at once, the load on the power devices of the power manufacturers supplying the power with a sine wave voltage increases, and it becomes impossible to maintain the voltage in the sine wave, There was a case where a power device was burned due to a current that exceeded the performance of the.

Therefore, in order to prevent such a problem, electronic devices adopting the capacitor input method are being regulated to suppress the input current peak. This regulation is called harmonic current suppression because the current as shown in FIG. 7 is regarded as a harmonic current having an n-th order when viewed in the frequency domain.

In response to this regulation, as a measure on the electronic equipment side, two methods are roughly proposed and implemented.

One is a so-called active filter system, which is a system in which a semiconductor element is used to actively suppress a harmonic current so as to approximate a sinusoidal waveform.

The other is called a reactor system, in which a reactor component is inserted in a part of an AC input circuit, and the impedance component of the reactor component causes a peak to flow to a capacitor. This is a method of suppressing current.

The former active filter method has an advantage that the harmonic current can be suppressed very effectively, but it requires a semiconductor element and a control circuit for controlling the same, which causes a problem that the countermeasure cost becomes high. there were.

On the other hand, in the latter reactor system,
Since it is possible to take countermeasures with only one part called a reactor in which a magnetic material is wound, there is an advantage that the countermeasure cost is low.

[0011]

However, when a countermeasure is taken with the reactor part, the magnetic noise radiated from the reactor part now becomes a problem. For example, if you try to mount a reactor component on the power supply circuit inside the housing of the television receiver, the leakage magnetic noise radiated from the reactor component may cause the screen of the television receiver to shake or distort. Had significantly reduced the quality of. The problems of screen shake and screen distortion are the same in the case of other CRT devices. Furthermore,
In general electronic equipment, magnetic noise may induce a voltage of a commercial frequency in an electronic circuit, causing malfunction of the circuit.

In order to solve these problems, it has been conventionally necessary to provide some kind of magnetic shield measure for suppressing leakage magnetic noise in the reactor parts. That is, it is necessary to provide a magnetic shield cover made of a magnetic material around the reactor parts or in the body of the reactor parts, and the original advantage of low countermeasure cost is lost.

Further, conventionally, the weight and volume of reactor parts have also been a problem. That is, in order to obtain the required harmonic current suppression effect with reactor parts, several mH to several tens m
An inductance of H is required, and a design that does not burn out even when a current of several hundred mA to several A is applied is required. Under such conditions, the weight of the reactor component alone becomes 100 g or more, and when it is mounted on the circuit board, the substrate is cracked or broken due to the weight of the reactor component during transportation. Further, it is necessary to provide a mounting space for mounting the reactor parts inside the electronic device body, which is a heavy burden particularly in the design of electronic devices which are becoming smaller.

Therefore, an object of the present invention is to reduce the influence of leakage magnetic noise generated from a reactor component on the electronic equipment body when suppressing a harmonic current using the reactor component, and to use the electronic equipment with the reactor component. An object of the present invention is to provide a power plug for electronic equipment that does not hinder the downsizing of the main body.

[0015]

In order to solve the above-mentioned problems, a power plug for electronic equipment of the present invention is attached to a casing made of resin and to the casing so as to project outward from the casing. A plug member made of a conductive material, a power supply line terminal provided in a part of the casing for connecting a power supply line of an electronic device, a plug member and the power supply line terminal arranged inside the casing. And at least one reactor part that is electrically connected to suppress the harmonic current.

[0016] In one aspect of the present invention, the reactor component is an iron core formed by stacking punched electromagnetic steel sheets and winding the winding.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in accordance with preferred embodiments with reference to the drawings.

As shown in FIGS. 1 to 6, in the present invention, a reactor component is used to suppress the harmonic current. However, the reactor component is not mounted in the electronic equipment main body as in the prior art, but A reactor part is provided in the power plug that is distant from the electronic equipment body.

As shown in FIGS. 1 and 2, the power plug of this embodiment has a resin casing consisting of a case 1 and a lid 3, and the lid 3 also serves as a mounting board for various components. There is. As the resin that constitutes this casing,
A resin such as phenol resin, styrene resin, vinyl chloride resin, etc., which has an electric insulating property for preventing electric shock and is easily molded is used.

The lid 3, which is a mounting board, has a mounting hole 301 for mounting the reactor component 2 and a power line terminal 30 for connecting the power cord 5 from an electronic device.
2 are provided respectively, and a metallic plug member 4 inserted into an insertion hole of an outlet or the like is attached through the lid 3.

The reactor part 2 is, as shown in FIG.
It is composed of iron cores 201 and 202 formed by stacking a plurality of E-shaped punched electromagnetic steel sheets having a thickness of 0.5 mm and containing Fe and Si as main components, and a winding frame 203 for winding. After winding the winding frame 203 with a copper wire, the iron cores 201 and 202 are combined through the winding frame 203 and impregnated with varnish to form the integral reactor component 2.

At this time, it is preferable to insert a vinyl film into the joint between the iron cores 201 and 202. This film plays a role of providing a gap in the magnetic circuit in the iron core and has a function of suppressing magnetic saturation of the iron core. Further, even if the dimension of the middle leg of the E-shaped iron core is made shorter than that of the outer leg and a space is provided in the magnetic circuit, the function of suppressing magnetic saturation is equivalent to the above-mentioned film insertion. . Therefore, in this case, it is not necessary to insert the film.

Further, the shapes of the iron cores 201 and 202 are not limited to the E-shape, but may be various shapes such as a U-shape or a combination of E-shape and I-shape. Further, the thickness of the electromagnetic steel sheet used is not limited to 0.5 mm, but the thinner the thickness, the more effectively the iron loss is suppressed by eddy currents. Is preferred.

Reactor component 2 constructed as described above
Then, the mounting bracket 204 shown in FIG. 4 is adhered, and as shown in FIG. 1, it is mounted in the mounting hole 301 of the lid 3 using the screw 6. In addition, as shown in FIG.
The through hole 208 is provided in the iron core 207 itself of the
The reactor component 2 may be attached through 08. Alternatively, the iron core may be previously welded to an iron chassis or the like and then attached to the lid 3 via the iron chassis.

A wiring diagram in the power plug is shown in FIG. 6 (a). The plug member 4 is connected to an AC power source via an outlet or the like. In this example, a 100V single-phase two-wire AC power source is connected. In the power plug, the lead wire 20 of the reactor component 2 is attached to one of the pair of plug members 4.
6 (see FIG. 1) is connected, and the lead wire 205 (see FIG. 1) of the reactor component 2 is connected to one of the power supply line terminals 302. The other power supply line terminal 302 is directly connected to the other plug member 4. As a result, the reactor component 2 is inserted in series into one of the two wires that connect the plug member 4 and the power supply wire terminal 302. When the input power source is a three-wire type, the ground wire may be insulated with a rubber tube or the like and passed through the power plug, and the remaining two wires are connected by the above method.

Although one reactor part is used in the embodiment described above, two small reactor parts each having an inductance value of half can be connected in series and used as an electric circuit. Since the total inductance value is the same as the case of one, the harmonic suppression effect does not change. When two pieces are used, they may be connected to both of the two wires as shown in FIG. 6 (b). As described above, the form using a plurality of reactor parts is suitable for fine adjustment of the number of reactor parts to be connected to electronic devices having different input current capacities and target harmonic suppression values.

According to the embodiment described above, even if magnetic noise is generated from the reactor component for suppressing harmonics, a maximum of the length of the power cord can be provided between the electronic device body and the outlet or the like. Since the distance can be secured, the electronic device body is less likely to be affected by the magnetic noise. Further, since it is not necessary to mount the reactor component inside the electronic device main body, there is no problem of substrate cracking due to the weight of the reactor component or securing of mounting space for the reactor component.

In the embodiment described above, F
Electromagnetic steel sheet mainly composed of e and Si and reactor parts 2
In the commercial frequency (50/60 Hz) region, an electromagnetic steel sheet containing Fe and Si as main components is inexpensive and has a saturation magnetic flux density of 1.6 among various magnetic materials.
Since the iron loss is lower than T, the iron core can be downsized, and a lightweight and inexpensive reactor part can be configured. As a result, the power plug, for example,
It is possible to prevent the power plug from falling off due to its own weight when it is connected to a wall outlet, and it is possible to reduce the size of the power plug itself.

[0029]

EXAMPLE An electromagnetic steel sheet 50A800 (JIS standard, sheet thickness 0.5 mm) was punched into an E shape and a plurality of sheets were laminated to form iron cores 201 and 202 as shown in FIG. The size of the iron core is a = 40 mm and b = 20 m in FIG.
m and c = 20 mm, and 40 electromagnetic steel plates were laminated. Next, a copper wire having a wire diameter of 0.6 mm was wound around the winding frame 203 150 times, and thereafter, the copper wire was combined with the iron cores 201 and 202. At this time, a 0.25 mm-thick vinyl film was inserted into the abutting portions of the iron cores 201 and 202. Then, using this reactor part 2, a power plug was prepared as shown in FIG. In addition, case 1 of FIG.
1mm thick phenolic resin, d = 67mm, e = 4
It was 0 mm and f = 80 mm. The wiring inside the power plug was as shown in FIG.

Using the power plug configured as described above,
The harmonic current was evaluated by the measurement system shown in FIG. As the measuring device 801, kikusui LIN40M-PCR-
L system, the power plug 802 according to the present invention,
The variable resistor 803, the rectifying diode 804, and the electrolytic capacitor (470 μF) 805 were connected as illustrated. The electric power at the time of measurement was adjusted by the variable resistor 803 so that the active electric power consumed was 150 W. Power supply is 100V / 50H
It was z.

The measurement results of the harmonic currents before and after connecting the power plug 802 according to the present invention are shown in [Table 1].

[0032]

[Table 1]

As can be seen from this [Table 1], by connecting the power plug 802 according to the present invention, the harmonic component of the current is effectively suppressed.

In addition, the same power plug as used above is
The power cord of a 25-inch size color television for consumer use was replaced and attached, and the effect of the leakage magnetic noise was measured by visually observing the television screen, but no problem occurred on the screen. This is because it is mainly the cathode ray tube electron gun that is affected by magnetic noise in the TV built-in parts, and even if the power plug with the built-in reactor parts is intentionally brought close to the TV outside the TV housing, the electron gun and the reactor are This is because the minimum distance to the component is 20 cm. Further, since the reactor parts are not built in the TV casing, there is no fear of cracking the board at all.

[0035]

EFFECTS OF THE INVENTION By using the power plug of the present invention, harmonic current can be suppressed, and at the same time, it becomes unnecessary to mount reactor parts in the electronic equipment body. Therefore, special leakage magnetic noise countermeasures are applied to the reactor parts. There is no need, and the cost can be reduced accordingly. In addition, there is no problem of substrate cracking or mounting space securing problem caused by mounting the reactor component inside the electronic device body.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a power plug according to an exemplary embodiment of the present invention.

FIG. 2 is an exploded perspective view of the power plug of FIG. 1 seen from another angle.

FIG. 3 is an exploded perspective view of a reactor part according to an embodiment of the present invention.

FIG. 4 is an exploded perspective view showing a method of attaching the reactor component according to the embodiment of the present invention.

FIG. 5 is a perspective view showing a method for mounting a reactor part according to another embodiment of the present invention.

FIG. 6 is a wiring diagram of a power plug according to one embodiment and another embodiment of the present invention.

FIG. 7 is a waveform diagram showing a waveform of a harmonic current.

FIG. 8 is a schematic diagram showing a measurement system for measuring a harmonic current.

[Explanation of symbols]

 1 Case 2 Reactor Parts 3 Lid 4 Plug Member 5 Power Cord 6 Screws 201, 202 Iron Core 203 Winding Frame 204 Mounting Hardware 301 Mounting Hole 302 Power Line Terminal 801 Measuring Device 802 Power Plug 803 Variable Resistor 804 Rectifying Diode 805 Electrolytic Capacitor

Claims (2)

[Claims] 1. A casing made of resin, a plug member made of a conductive material attached to the casing so as to project outward from the casing, and a part of the casing for connecting a power line of an electronic device. A power supply line terminal, and at least one reactor part arranged inside the casing and electrically connected between the plug member and the power supply line terminal to suppress a harmonic current. A power plug for electronic equipment, characterized by being provided with. 2. The power plug for electronic equipment according to claim 1, wherein the reactor part is an iron core formed by stacking punched electromagnetic steel sheets and winding the iron core.