JP2023043571A - Power supply unit and light emitting device - Google Patents

Abstract

To achieve a power supply unit with reduced radiation noise.SOLUTION: A power supply unit (2) for lighting an LED light source (3) includes: an input unit (21); a noise filter (22); an output unit (25); an impedance element (26) and a first capacitor (27) connected in series; and a second capacitor (28) whose one end is connected to the output unit (25) and whose other end is connected to a ground terminal. One end of either impedance element (26) or first capacitor (27) is connected to the noise filter (22) and the other end is connected to the ground terminal.SELECTED DRAWING: Figure 1

Description

The present invention relates to a power supply unit for lighting light emitting diode elements.

Patent Literature 1 discloses an LED lighting device comprising a power supply unit that receives an input from an AC power supply and an LED (Light Emitting Diode) element connected to the power supply unit via wiring. The power supply unit of the cited example solves problems such as common mode noise from the input power supply and prevents malfunction due to radiation noise from LED elements or cables. and an inductor on the line.

JP 2013-143807 A

However, the regulatory standards for noise are becoming stricter year by year, and in addition to preventing malfunction, emission of radiation noise is also regulated. Specifically, the PSE noise regulation standards are scheduled to be revised to CISPRJ15, and CISPRJ15 defines the frequency band of noise electric field strength as 30 MHz to 300 MHz. Therefore, reducing the frequency band of radiation noise is necessary for PSE adaptation.

Further, when both the AC section and the DC section of the power supply unit are provided with a Y capacitor connected to the ground terminal, most of the common mode noise can be removed through the ground terminal by the Y capacitor on the AC section side. However, if noise removal from the ground terminal is not ideal, the noise that cannot be removed by the Y capacitor on the AC section side propagates to the DC section as noise through the Y capacitor on the DC section side. Therefore, radiation noise is emitted from the LED element, the cable, or the like.

In particular, if the total length of the connection path including all cables, substrates, etc. connecting the Y capacitor on the AC section side and the LED element is as long as 1200 mm, the total connection path will function as an antenna. It becomes a noise source. As a result, the LED element emits radiation noise between 100 MHz and 300 MHz, depending on the antenna length.

Accordingly, an object of one embodiment of the present invention is to realize a power supply unit with reduced radiation noise.

In order to solve the above problems, a power supply unit according to one aspect of the present invention is a power supply unit for lighting a light-emitting diode element, comprising: an input unit to which AC power is input; a noise filter arranged between the input unit and the conversion unit; an output unit for outputting the DC power to the light emitting diode element; an impedance element connected in series with the first and a second capacitor having one end connected to the output section and the other end connected to a ground terminal, wherein one end of either the impedance element or the first capacitor is connected to the noise filter. and the other end is connected to the ground terminal.

According to one aspect of the present invention, it is possible to realize a power supply unit with reduced radiation noise.

1 is a diagram showing a circuit diagram of an LED lighting device according to Embodiment 1. FIG. FIG. 10 is a diagram showing a circuit diagram of an LED lighting device according to Embodiment 2; FIG. 10 is a diagram showing a circuit diagram of an LED lighting device according to Embodiment 3; FIG. 10 is a diagram showing a circuit diagram of an LED lighting device according to Embodiment 4;

[Embodiment 1]
An embodiment of the present invention will be described in detail below.

(Configuration of LED lighting device)
FIG. 1 is a diagram showing a circuit diagram of an LED lighting device 1 (light emitting device) according to Embodiment 1. FIG. As shown in this figure, the LED lighting device 1 includes a power supply unit 2 and an LED light source 3 .

The power supply unit 2 includes an input section 21 , a noise filter 22 , a conversion section 23 , a line filter 24 , an output section 25 , an impedance element 26 , a first capacitor 27 and a second capacitor 28 .

The input unit 21 inputs AC power from the AC power supply 41 . The input unit 21 outputs the input AC power to the noise filter 22 .

The noise filter 22 removes AC component noise from the input AC power by filtering noise contained in the input AC power. Furthermore, the noise filter 22 removes noise from the converter 23 so that the noise does not leak to the AC power supply 41 . The noise filter 22 outputs the filtered AC power to the converter 23 .

The noise filter 22 may be composed of a single-phase two-stage filter circuit or a single-phase one-stage filter circuit using a common mode choke coil. Specifically, as noise filter 22 , a first common mode choke coil and a second common mode choke coil are connected in order between AC power supply 41 and converter 23 . Furthermore, the first X capacitor is connected between the connection points of the AC power supply 41 and the first common mode choke coil, the second X capacitor is connected between the connection points of the first common mode choke coil and the second common mode choke coil, and the second A 3X capacitor is connected between the connection points of the second common mode choke coil and the conversion section 23 . Here, the secondary side of the first common mode choke coil, one pole of the second X capacitor, and the primary side of the second common mode choke coil are connected to the first capacitor 27 .

The conversion unit 23 converts the input AC power into DC power. The conversion unit 23 may be a switching power supply that includes a transformer and switching elements. The converter 23 outputs the converted DC power to the line filter 24 .

The line filter 24 is arranged between the conversion section 23 and the output section 25 . The line filter 24 removes the switching noise contained in the input DC power by filtering the switching noise contained in the DC power. The line filter 24 outputs the filtered DC power to the output section 25 .

The line filter 24 may be a common mode choke coil. As the line filter 24 , a third common mode choke coil is connected between the conversion section 23 and the output section 25 . A third capacitor may be connected between the connection points of the conversion section 23 and the third common mode choke coil, and a fourth capacitor may be connected between the connection points of the third common mode choke coil and the output section 25 . Furthermore, a second capacitor 28 is connected to the secondary side of the third common mode choke coil and one pole of the fourth capacitor.

The output unit 25 outputs the input DC power to the LED light source 3 .

The impedance element 26 and the first capacitor 27 are connected in series. Impedance element 26 may be composed of at least one of a coil and a resistor. In this embodiment, the impedance element 26 shall be comprised by the coil. Also, the first capacitor 27 may be a Y capacitor.

In the power supply unit 2, one end of either the impedance element 26 or the first capacitor 27 is connected to the noise filter 22, and the other end is connected to the ground terminal. In the example shown in FIG. 1 , one end of the impedance element 26 is connected to the noise filter 22 and the other end of the impedance element 26 is connected to one end of the first capacitor 27 . The other end of the first capacitor 27 is connected to the ground terminal.

Alternatively, the positions of the impedance element 26 and the first capacitor 27 may be interchanged. That is, one end of the first capacitor 27 may be connected to the noise filter 22 and the other end of the first capacitor 27 may be connected to one end of the impedance element 26 . In this configuration, the other end of impedance element 26 is connected to the ground terminal. Even if the connection order of the impedance element 26 and the first capacitor 27 is changed, the impedance element 26 and the first capacitor 27 can play the same role as before the connection order is changed.

A second capacitor 28 is connected between the output section 25 and the ground terminal. That is, one end of the second capacitor 28 is connected to the output section, and the other end is connected to the ground terminal. Also, the second capacitor 28 may be a Y capacitor.

The ground terminal may be the metal housing of the power supply unit 2 . The ground terminal is also connected to the ground terminal of the AC power supply 41 input by the input section 21 .

The LED light source 3 has a light-emitting diode element (LED element) inside, and emits light with the DC power input from the power supply unit 2 . That is, the power supply unit 2 is a unit for lighting the LED elements of the LED light source 3 .

(Operation of LED lighting device)
When the first capacitor 27 and the second capacitor 28 are Y capacitors, the Y capacitor is generally effective against noise of 1 MHz or higher and has the effect of reducing common mode noise.

However, as described above, in general, common mode noise mixed from the conversion unit 23 is emitted from the light emitting device as radiation noise from the capacitor connected to the AC section side through the capacitor connected to the DC section side. There is something.

In the power supply unit 2 shown in FIG. 1, the impedance element 26 inhibits the propagation of the noise from the AC section side to the DC section side or reduces the noise energy. Therefore, by connecting the impedance element 26 and the first capacitor 27 in series, the generation of radiation noise can be suppressed.

[Embodiment 2]
Other embodiments of the invention are described below. For convenience of description, members having the same functions as those of the members described in the above embodiments are denoted by the same reference numerals, and description thereof will not be repeated.

FIG. 2 shows a circuit diagram of an LED lighting device 1a according to Embodiment 2. As shown in FIG. Unlike the LED lighting device 1, the LED lighting device 1a includes a coil 26a and a resistor 26b connected in parallel instead of the impedance element 26. FIG.

When low-frequency noise (30 MHz to 100 MHz) of 100 MHz or less is mixed, the coil 26a can release the noise to the ground terminal without suppressing the current change due to the low frequency. Also, when high-frequency noise (100 MHz to 300 MHz) higher than 100 MHz is mixed, the coil 26a blocks the noise because of the high frequency, and the resistor 26b reduces the noise current while allowing the noise to escape to the ground terminal. Become.

Here, if a structure is adopted in which noise is completely prevented from escaping to the ground terminal, the noise will flow to the AC power supply 41 in a device in which noise is mixed or generated. Therefore, it is necessary to release the mixed noise or generated noise to the ground terminal.

Therefore, by forming the impedance element 26 into a parallel structure of a coil 26a and a resistor 26b, low-frequency noise (30 MHz to 100 MHz) can be released to the ground terminal. Therefore, the function of reducing the noise current flowing to the AC power supply line can be obtained without impeding the noise reduction function of the first capacitor. In addition, this effect does not hinder the noise reduction function of the first capacitor. Note that the coil referred to here includes not only general coils but also chip inductors, ferrite beads, and chip ferrite beads, as long as they have the function of allowing the low-frequency current to pass through without suppressing changes.

[Embodiment 3]
Other embodiments of the invention are described below. For convenience of description, members having the same functions as those of the members described in the above embodiments are denoted by the same reference numerals, and description thereof will not be repeated.

FIG. 3 shows a circuit diagram of an LED lighting device 1b according to Embodiment 3. As shown in FIG. The LED lighting device 1 b is different from the LED lighting device 1 in that the power supply unit 2 is provided with the first dummy wiring 29 .

The first dummy wiring 29 is a wiring having one end connected to the output section 25 and the other end electrically floating. The electrically floating wiring may be a copper foil pattern or wire on the substrate. Therefore, since an antenna separate from the antenna of the LED light source 3 is formed inside the power supply unit 2, noise energy that causes radiation noise can be reduced. By reducing the noise energy, it is possible to suppress the generation of radiation noise.

Therefore, by providing the power supply unit 2 with the first dummy wiring 29, the radiation noise can be reduced.

[Embodiment 4]
Other embodiments of the invention are described below. For convenience of description, members having the same functions as those of the members described in the above embodiments are denoted by the same reference numerals, and description thereof will not be repeated.

FIG. 4 shows a circuit diagram of an LED lighting device 1c according to Embodiment 4. As shown in FIG. The LED lighting device 1 c differs from the LED lighting device 1 in that the LED light source 3 is provided with a second dummy wiring 31 . That is, the LED lighting device 1 c further includes a substrate (not shown) on which the LED elements of the LED light source 3 are arranged, and a second dummy wiring 31 wired on the substrate of the LED light source 3 .

The second dummy wiring 31 is a wiring having one end connected to the substrate of the LED light source 3 and the other end electrically floating. The electrically floating wiring may be a copper foil pattern or wire on the substrate. Therefore, since the second dummy wiring forms an antenna separate from the antenna of the LED light source 3 inside the power supply unit 2, the noise energy that causes the radiation noise can be reduced by distributing it. By reducing the noise energy, it is possible to suppress the generation of radiation noise.

Therefore, by providing the LED light source 3 with the second dummy wiring 31, the radiation noise can be reduced.

〔summary〕
A power supply unit according to aspect 1 of the present invention is a power supply unit for lighting a light-emitting diode element, comprising: an input unit to which AC power is input; a conversion unit that converts the AC power into DC power; a noise filter disposed between the unit and the conversion unit; an output unit that outputs the DC power to the light emitting diode element; an impedance element and a first capacitor that are connected in series; a second capacitor connected to the noise filter and having the other end connected to a ground terminal, wherein one end of one of the impedance element and the first capacitor is connected to the noise filter, and the other end of the other is grounded connected to the terminal.

According to the above configuration, radiation noise emitted by the power supply unit can be reduced.

In the power supply unit according to aspect 2 of the present invention, in the above aspect 1, the impedance element may be composed of at least one of a coil and a resistor.

According to the above configuration, noise energy can be reduced by configuring the impedance element with at least one of the coil and the resistor.

In the power supply unit according to aspect 3 of the present invention, in aspect 2 above, the impedance element may be configured by the coil and the resistor connected in parallel to each other.

According to the above configuration, the impedance element is composed of a coil and a resistor that are connected in parallel with each other, so that noise energy can be reduced in a frequency band in which radiation noise occurs.

A power supply unit according to aspect 4 of the present invention may further include a first dummy wiring having one end connected to the output section and the other end electrically floating in the above aspects 1 to 3.

According to the above configuration, the first dummy wiring can reduce the noise energy that causes the radiation noise emitted by the power supply unit.

A power supply unit according to aspect 5 of the present invention may further include a line filter arranged between the conversion unit and the output unit in the above aspects 1 to 4.

According to the above configuration, noise mixed in the DC power converted by the converter can be filtered. Therefore, it leads to reduction of radiation noise.

A light-emitting device according to aspect 6 of the present invention includes the power supply unit according to aspects 1 to 5 and the light-emitting diode element.

According to the above configuration, by connecting the light-emitting device to the power supply unit in which radiation noise is reduced, the light-emitting device can be used with reduced emission of radiation noise.

A light-emitting device according to aspect 7 of the present invention is the light-emitting device according to aspect 6, further comprising: a substrate on which the light-emitting diode element is arranged; and a second dummy wiring that is connected and whose other end is electrically floating.

According to the above configuration, the second dummy wiring can reduce the noise energy that causes the radiation noise emitted by the light emitting device.

The present invention is not limited to the above-described embodiments, but can be modified in various ways within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. is also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

1, 1a, 1b, 1c LED lighting device (light emitting device)
2 power supply unit 3 LED light source 21 input section 22 noise filter 23 conversion section 24 line filter 25 output section 26 impedance element 26a coil 26b resistor 27 first capacitor 28 second capacitor 29 first dummy wiring 31 second dummy wiring 41 AC power supply

Claims (7)

A power supply unit for lighting a light-emitting diode element,
an input unit into which AC power is input;
a conversion unit that converts the AC power to DC power;
a noise filter arranged between the input unit and the conversion unit;
an output unit that outputs the DC power to the light emitting diode element;
an impedance element and a first capacitor connected in series;
a second capacitor having one end connected to the output section and the other end connected to a ground terminal;
A power supply unit, wherein one end of one of the impedance element and the first capacitor is connected to the noise filter, and the other end of the other is connected to a ground terminal. 2. A power supply unit according to claim 1, wherein said impedance element comprises at least one of a coil and a resistor. 3. A power supply unit according to claim 2, wherein said impedance element comprises said coil and said resistor which are connected in parallel with each other. 4. The power supply unit according to any one of claims 1 to 3, further comprising a first dummy wiring having one end connected to the output section and the other end electrically floating. . 5. The power supply unit according to any one of claims 1 to 4, further comprising a line filter arranged between said conversion section and said output section. A power supply unit according to any one of claims 1 to 5;
A light-emitting device comprising: the light-emitting diode element. a substrate on which the light emitting diode element is arranged;
a second dummy wiring that is wired on the substrate, one end of which is connected to the output section and the other end of which is electrically floating; 7. A light emitting device according to claim 6.

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