KR101692584B1 - A lighting device - Google Patents

Abstract

The illumination device of the embodiment includes an input power source connected to an external power source, a current output unit for converting a current outputted from the input power source unit into a high frequency current and outputting the current, Wherein the LED light source includes a first channel light source including at least one or more LED elements, and a second channel light source including a first channel light source and a second channel light source, And a second channel light source supplied with a current different from the current supplied to the light source, wherein the low band pass filter comprises: a first signal line connected to the first channel light source; A first return line through which a current is returned to the current output section, a second signal line connected with the second channel light source, And a second feedback line through which a current having passed through the current output section is returned to the current output section.

Description

[0001] The present invention relates to a lighting device,

The present invention relates to a lighting apparatus using LED elements as a light source, and more particularly, to a lighting apparatus provided with a circuit capable of effectively eliminating low frequencies while reducing the number of filters for eliminating noise included in currents supplied to LED elements It is about.

With the development of the semiconductor industry, the use of various electronic devices has increased, and it is now possible to easily access electronic devices in the vicinity, and the electronic devices have been helped. However, electromagnetic waves generated from such electronic devices are directly or indirectly influenced by other devices or the human body, and damage caused by such electromagnetic waves is known.

Such electromagnetic disturbance can be divided into a conductive fault occurring in the power source of the electronic apparatus and a radioactive fault generated directly in the electronic apparatus. Particularly, many attempts have been made to remove the radioactive fault generated directly from the electronic apparatus by using a filter or the like have.

In order to solve such a radioactive disturbance, a method of shielding a transformer in a low frequency band and improving a radio noise by using a ferrite (Mn / Zn) filter in a high frequency band is generally used.

Conventional lighting converters have a long output wire, which makes it difficult to solve the radio noise in the SMPS circuit. To do this, a low-pass filter is used at both ends of the output to pass only the low-frequency signal and the high-frequency noise signal is cut off. However, when designing a multi-output converter, it is necessary to design a separate low-pass filter for each output stage, which increases the manufacturing cost of the converter for lighting due to the number of filters. Further, since the space of the internal circuit of the converter for lighting is occupied by a large number of filters, circuit design is also difficult.

The present invention proposes a method of effectively removing noise included in a current supplied to an LED device in an illumination device using an LED device as a light source.

Also, it is proposed to reduce the ripple phenomenon by removing the noise included in the current supplied to the LED element, and to reduce the number of filters required for noise reduction by half compared to the conventional art.

The illumination device of the embodiment includes an input power source connected to an external power source, a current output unit for converting a current outputted from the input power source unit into a high frequency current and outputting the current, Wherein the LED light source includes a first channel light source including at least one or more LED elements, and a second channel light source including a first channel light source and a second channel light source, And a second channel light source that is supplied with a current different from a current supplied to the light source, wherein the low band pass filter includes: a first signal line connected to the first channel light source; A first return line through which a current is returned to the current output section, a second signal line connected with the second channel light source, And a second feedback line through which a current having passed through the current output section is returned to the current output section.

The illumination device as proposed has the advantage that noise such as ripple included in the current flowing through the light source made of the LED element can be effectively removed.

Further, since a filter for removing noise can be provided for each of the pair of light sources, it is possible to reduce the circuit area for controlling the lighting device, thereby making it possible to perform the circuit design more effectively have.

In the circuit provided with the noise elimination filter according to the present embodiment, the design for changing the stray capacitance is easy, and radiation noise can be suppressed through bypassing noise.

1 is a view showing a circuit of a lighting apparatus of this embodiment.
FIG. 2 is a diagram illustrating an example of a low-pass filter for noise reduction for a plurality of channels according to an embodiment.
3 is a diagram showing the configuration of the lighting apparatus of this embodiment in more detail.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing a circuit of a lighting apparatus of this embodiment.

Referring to FIG. 1, a description will be given of a structure for reducing noise using one low-pass filter for LED elements formed of separate channels according to the present embodiment.

In designing a multi-channel power supply circuit, it is common to form a low-pass filter for each channel, but in the proposed embodiment, the core of the low-pass filter has a first coil winding And a second coil winding for winding the coil in a direction opposite to the first coil winding to serve as a filter for the second channel.

With this configuration, the two channels can be filtered at the same time, and a bypass filter can be constructed by adding a capacitor connected to the low-pass filter. Such a bypass filter can be used for both outputs, and can achieve the same noise reduction effect as in the case of a low-pass filter design for each channel.

In the following description, for at least one or more LED elements, at least one or more LED elements disposed on the same path of current for driving the LED elements is referred to as one channel. That is, one channel may include an illumination device in which only one LED element is disposed, or an illumination device in which a plurality of LED elements are arranged, and in a case where currents supplied to the LED elements have the same path, It can be seen that the devices constitute one channel.

In addition, a low-pass filter is proposed as a filter for eliminating noise and ripple included in the current supplied to the LED elements, and it is also possible to call this low-pass filter as a line filter or a noise canceling filter.

1, the lighting apparatus of this embodiment includes an input power source 30, a drive IC 10 for controlling the inverter to supply a current of a dimming target of the LED light source to an input power source, And a single low pass filter (100) for removing noise against current supplied to the channel.

For convenience of explanation of this embodiment, only LED light sources of two channels are shown for an LED light source. The current flowing through the LED light source is referred to as an LED current. As previously defined, LEDs (light sources) operated by the same LED current can be referred to as one channel.

The low pass filter 100 of the embodiment is designed to pass a first LED current and a second LED current, the first LED current operating the LED light source of the first channel, To operate the LED light source.

In particular, the low pass filter 100 may be a common mode filter for attenuating common mode noise, and the low pass filter 100 may include a pair of smoothing units 200 for canceling high frequency noises, Lt; / RTI > Here, the smoothing unit 200 may be formed of a ceramic capacitor. In order to remove the high frequency noise included in the LED current supplied to the LED light source, the low-pass filter 100 may be bypassed Filter.

In detail, the smoothing unit 200 composed of a pair of capacitors serves to suppress unnecessary RF noise coupling to a region where the common mode noise of the element or cable is highly susceptible. There is always a capacitance between the power supply and the ground due to the thickness of the inner core material and the dielectric constant of the material, which is a potential RF emitter and is a factor that determines the total self-resonant frequency, which can directly affect the electromagnetic noise .

Therefore, by connecting the smoothing part 200 to the front end of the low-pass filter 100, it is possible for the circuit designer to change the self-resonance frequency by adjusting the capacitance of the smoothing part 200. That is, the optimization design for suppressing the radiation noise for each pair of LED channels is facilitated.

The low-pass filter 100 of the embodiment will be described in detail.

The low pass filter 100 of the embodiment is a common mode filter for attenuating common mode noise and is connected between the smoothing part 200 and the LED light source.

The low pass filter 100 includes a first coil 110 and a second coil 120. The LED light sources constituting each channel are provided with input signal lines and output signal lines, respectively.

The first signal line from the first connecting point 111 to the third connecting point 113 and the first return line from the seventh connecting point 123 to the fifth connecting point 121 are connected to the first signal line .

For the LED light source of the second channel, the second signal line from the second connection point 112 to the fourth connection point 114 and the second signal line from the eighth connection point 124 to the sixth connection point 122 Lines are formed.

More specifically, the first signal line of the first LED current supplied to the LED light source of the first channel is connected to the first connection point 111 of the low-pass filter 100, the first coil portion 110, (113).

The first return line which is output from the LED light source of the first channel and returns to the drive IC 10 is the wiring leading to the seventh connection point 123, the second coil portion 120 and the fifth connection point 121 .

On the other hand, the second signal line of the second LED current supplied to the LED light source of the second channel is connected to the second connection point 112, the first coil part 110 and the fourth connection point 114 of the low pass filter 100 ).

The second return line which is output from the LED light source of the second channel and returns to the drive IC 10 is a wiring leading to the eighth connection point 124, the second coil portion 120 and the sixth connection point 122 .

The first coil part 110 constitutes part of the signal lines for the LED light sources of different channels and the second coil part 120 constitutes part of the return line for the different channels. According to another expression, the first coil portion 110 is provided between the first and second signal lines, and the second coil portion 120 is provided between the first and second return lines.

The low-pass filter thus configured can be implemented with the configuration as shown in Fig. FIG. 2 is a diagram illustrating an example of a low-pass filter for noise reduction for a plurality of channels according to an embodiment.

Referring to FIG. 2, the low-pass filter of the embodiment shares a single core and can pass LED currents supplied to the LED light sources of different channels, eliminating the high frequency noise included in the LED currents can do.

The first signal lines 111 and 113 of the first LED current and the first feedback lines 121 and 123 of the first LED current transmitted to the LED light source of the first channel are wound on a part of the core. The second signal lines 112 and 114 of the second LED current and the second feedback lines 122 and 124 of the second LED current, which are transmitted to the LED light source of the second channel, are wound in the opposite direction to the rest of the core.

By the low-pass filter having such a configuration, a pair of coils are wound around a part of one core, and a pair of coils are wound in the other part of the core in the opposite direction, so that high frequency components Can be removed.

In such a low-pass filter 100, the first coil part 110 and the second coil part 120 are paired to attenuate the common mode noise moving along the signal lines and the feedback lines. That is, the first signal lines 111 and 113 connected to the LED light source of the first channel and the coils of the first feedback lines 121 and 123 are wound in the same direction, and signals in the same direction, that is, common mode noise, When the magnetic flux generated in the core is strong, the action of blocking the signals flowing through the first signal line and the first feedback line becomes strong. As a result, the common mode noise passing through the low pass filter is attenuated. This phenomenon is also applied to the second signal line connected to the LED light source of the second channel and the coil of the second signal line.

This low-pass filter 100 is connected between the smoothing unit 200 and a plurality of LED light sources in accordance with the present embodiment. That is, the low-pass filter 100 maintains a connected state just before the LED light source. With this configuration, the current immediately after the common mode noise is reduced by the low-pass filter 100 can be supplied to the LED light source, and it is possible to supply current to the LED light source before the new common mode noise is added It becomes.

On the other hand, the smoothing portion 200 of the embodiment is disposed between the drive IC 10 and the low-pass filter 100. In detail, the smoothing unit 200 is connected between the inverter and the low-pass filter 100. [

The smoothing unit 200 is composed of a pair of first and second smoothing capacitors 210 and 220, the first smoothing capacitor 210 is connected to the first signal line of the first channel, (220) is connected to the second signal line of the second channel.

The other ends of the first and second smoothing capacitors 210 and 220 are grounded. In operation, a filter-like action can be referred to as a shield against noise transmitted through a circuit, and such a shield can operate only when a third electrode is formed between those coupled with a stray capacitance. If there is no potential difference between the capacitors coupled between different power supplies, no stray capacitance is formed between the two ends of the capacitor. By designing the third electrode between the two poles, a stray capacitance is generated between both ends. Thereby generating a bypass path.

Such a circuit configuration may be referred to as an electrostatic shield. The smoothing unit 200 including the first and second smoothing capacitors 210 and 220 of the embodiment can be designed by changing the stray capacitance for each channel, Thereby suppressing the radiation noise.

A more detailed embodiment will be attached to the illumination device having the filter configuration as described above.

3 is a diagram showing the configuration of the lighting apparatus of this embodiment in more detail.

3, the inverter unit 40, the resonant circuit 50, the rectifying unit 60, the low-pass filter 60, and the low-pass filter 60 are connected to each other, A filter 100, a drive IC 10, and a smoothing portion 200.

Here, the inverter unit 40, the resonant circuit 50, and the rectifier unit 60 serve as a current output unit.

The input power supply unit 30 includes a power supply rectifying circuit 31 and a phase adjusting unit 32. The input power source unit 30 is connected to a commercial power source, and the commercial power source is an AC power source such as an outlet.

The power supply rectifying circuit 31 may be composed of a noise filter and a diode bridge. The power supply rectifying circuit 31 is supplied with an alternating current from a commercial power supply, and performs rectification by reducing the noise of the supplied alternating current.

The phase adjusting unit 32 performs switching according to a change in the output voltage output by the power rectifying circuit 31. The phase adjusting unit 32 adjusts the phase of the current output by the power rectifying circuit 31 to improve the power factor , Suppressing harmonics. Then, the phase adjusting unit 32 outputs a voltage whose power factor is improved and whose harmonics are suppressed, to the inverter unit 40.

The inverter unit 40 includes a first switching device 41 and a second switching device 42. The inverter unit 40 converts a current supplied from the input power source unit 30 into a high frequency current , AC power) and outputs it.

In other words, the inverter unit 40 is under the control of the drive IC 10 in order to supply the LED light source with the current of the dimming target value. Here, the drive IC 10 generates a square wave voltage having a predetermined frequency and a predetermined duty ratio for the purpose of controlling the inverter section 40.

The first switching device 41 and the second switching device 42 are operated such that the square wave voltage generated by the drive IC 10 is reverse polarity between the switching devices. The first switching device 41 and the second switching device 42 are alternately switched in accordance with the rectangular-wave voltage generated by the drive IC 10, thereby generating a high-frequency current corresponding to the square-wave voltage.

The resonance circuit 50 has a resonance characteristic (frequency characteristic of impedance) determined by the resonance capacitor 51 and the resonance inductor 52. The resonance frequency of the resonance capacitor 51 and resonance inductor 52 Causing resonance to occur. A current outputted from the inverter section 40 is applied to the resonance circuit 50 and a current corresponding to the impedance of the resonance circuit 50 flows to the frequency of the applied output current.

The rectifying unit 60 may be a full wave rectifying circuit or a diode bridge circuit composed of four diodes. The rectifying unit 60 is a circuit that rectifies the high frequency current output from the inverter unit 40 and that is changed in size by the resonance circuit 50 and converts the rectified current into a rectified current.

Although not shown, a current detection resistor for measuring the LED current value can be further constituted by constituting a resistor on a line output from the LED light source and returning.

Meanwhile, as described above, the smoothing unit 200 is further provided together with the low-pass filter 100 as a means for removing the noise included in the LED current. The smoothing unit 200 includes a first smoothing capacitor 210 and a second smoothing capacitor 220 connected in parallel and the first smoothing capacitor 210 is connected to a first signal line of the first channel, The second smoothing capacitor 220 is connected to the second signal line of the second channel. The other ends of the first and second smoothing capacitors 210 and 220 are grounded.

Due to the configuration of the smoothing unit 200, the noise of the high-frequency component can be removed while passing through the low-pass filter 100 of the LED current with the primary noise removed.

The power supply circuit of the lighting apparatus configured as described above makes it unnecessary to form a line filter for each LED light source for each channel, and as a result, the number of filters can be reduced to half, Of course, there is an advantage in that space can be easily secured when designing a power supply circuit.

Claims (5)

An input power unit connected to an external power source,
A current output unit for converting a current outputted from the input power supply unit into a high frequency current and outputting the converted high frequency current,
A low-pass filter for removing noise from the current outputted from the current output unit,
And an LED light source operated by supplying a current output from the low-pass filter,
Wherein the LED light source includes a first channel light source including at least one LED element and a second channel light source supplied with a current different from a current supplied to the first channel light source,
Wherein the low-
A first signal line connected to the anode of the first channel light source, a first feedback line connected to the cathode of the first channel light source and through which the current passed through the first channel light source returns to the current output unit,
A second signal line connected to the anode of the second channel light source and a second feedback line connected to the cathode of the second channel light source and through which the current having passed through the second channel light source returns to the current output unit,
Wherein the first signal line and the first feedback line form a pair of first coils, the pair of first coils are wound on a part of the core in a first direction,
The second signal line and the second feedback line constitute a pair of second coils and the pair of second coils are wound on the remainder of the core in a second direction opposite to the first direction,
Wherein the pair of first coils wound in the first direction attenuates common mode noise for the first channel light source,
And the pair of second coils wound in the second direction attenuates common mode noise for the second channel light source
Lighting device. delete delete The method according to claim 1,
Further comprising a smoothing unit, provided between the current output unit and the low-pass filter, for removing noise of a high-frequency component of a current,
Wherein the smoothing portion includes a first smoothing capacitor coupled to the first signal line and a second smoothing capacitor coupled to the second signal line. 5. The method of claim 4,
And both ends of the first and second smoothing capacitors are connected to ground.

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