JP2009266696A - Light emitting diode lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting diode lighting system usable by being mounted to an existing luminaire for a fluorescent tube, and capable of preventing increase of the number of circuits. <P>SOLUTION: This light emitting diode lighting system is provided with: a light emitting circuit 10 including light emitting diodes 11-1n; an illumination cover 200 arranged inside the light emitting circuit 10, and permeable by light emitted from the light emitting diodes 11-1n; a first electrode pin 41 and a second electrode pin 42 arranged at one-side end in the longitudinal direction of the illumination cover 200 and short-circuited to each other, and a third electrode pin 43 and a fourth electrode pin 44 arranged at the other-side end in the longitudinal direction of the illumination cover 200 and short-circuited to each other; and a rectifier circuit 20 rectifying AC power applied between the first electrode pin 41 and the third electrode pin 43 and AC power applied between the second electrode pin 42 and the fourth electrode pin 44 to DC power, and supplying the DC power to the light emitting diodes 11-11n. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light emitting diode illumination device using a light emitting diode as a light source.

  In recent years, an illuminating device using a light emitting diode (LED) as a light source instead of a fluorescent lamp or the like has been put into practical use. By using a light emitting diode as a light source, effects such as long life and energy saving can be obtained as compared with the case of using a fluorescent lamp.

In particular, if a light-emitting diode illuminating device using a light-emitting diode can be attached to an existing fluorescent tube luminaire instead of a fluorescent tube, it is not necessary to modify the fluorescent tube luminaire and the existing equipment can be used as it is. (For example, refer to Patent Document 1). Here, the fluorescent tube lighting fixture is a fixture that supports the fluorescent tube and functions as a power source for supplying power to the fluorescent tube.
JP 2004-192833 A

  However, the light-emitting diode illuminating device having the configuration described in Patent Document 1 requires a large number of circuits such as requiring a plurality of rectifying bridge diodes. For this reason, there existed a problem that the circuit arrangement area | regions other than a light emission area increased, and the manufacturing cost raised.

  In view of the above problems, an object of the present invention is to provide a light-emitting diode illuminating device that can be used by being attached to an existing fluorescent tube lighting fixture and can suppress an increase in the number of circuits.

  According to one aspect of the present invention, (a) a light emitting circuit including a light emitting diode, (b) an illumination cover in which the light emitting circuit is disposed inside, and light emitted from the light emitting diode is transmitted; A first electrode pin and a second electrode pin arranged at one end in the direction and short-circuited with each other, and a third electrode pin and a fourth electrode arranged at the other end in the longitudinal direction of the lighting cover and short-circuited from each other An electrode pin; and (d) rectifying AC power applied between the first electrode pin and the third electrode pin and AC power applied between the second electrode pin and the fourth electrode pin into DC power, and converting the DC power to a light emitting diode. There is provided a light-emitting diode illuminating device including a rectifier circuit for supplying to a rectifier.

  ADVANTAGE OF THE INVENTION According to this invention, the light emitting diode illuminating device which can be mounted | worn and used for the existing lighting fixture for fluorescent tubes, and can suppress the increase in the number of circuits can be provided.

  Next, first and second embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the lengths of the respective parts, and the like are different from the actual ones. Therefore, specific dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  Further, the first and second embodiments shown below exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is the shape of component parts. The structure, arrangement, etc. are not specified below. The technical idea of the present invention can be variously modified within the scope of the claims.

(First embodiment)
The light-emitting diode illuminating device 1 according to the first embodiment of the present invention includes a light-emitting circuit 10 including light-emitting diodes 11 to 1n, and an illumination in which the light-emitting circuit 10 is disposed on the inner side and light emitted from the light-emitting diodes 11 to 1n is transmitted. The cover 200, the first electrode pin 41 and the second electrode pin 42 disposed at one end in the longitudinal direction of the lighting cover 200 and short-circuited with each other, and the other end in the longitudinal direction of the lighting cover 200 are disposed. The third electrode pin 43 and the fourth electrode pin 44 short-circuited with each other, the AC power applied between the first electrode pin 41 and the third electrode pin 43, and between the second electrode pin 42 and the fourth electrode pin 44. And a rectifier circuit 20 that rectifies the applied AC power to DC power and supplies the DC power to the light emitting diodes 11 to 1n (n: an integer of 2 or more). The light emitting circuit 10 has a structure in which the light emitting diodes 11 to 1n are connected in series. The anode of the light emitting diode 11 is connected to the input terminal P101 of the light emitting circuit 10, and the cathode of the light emitting diode 1n is connected to the output terminal P102 of the light emitting circuit 10. To do.

  In the example illustrated in FIG. 1, the light emitting circuit 10 and the rectifier circuit 20 are disposed on the substrate 100, and the substrate 100 is accommodated in a lighting cover 200 that is a hollow casing. The first electrode pin 41 and the second electrode pin 42 are disposed on the first terminal portion 210 that constitutes one end portion of the lighting cover 200 in the longitudinal direction. In addition, the third electrode pin 43 and the fourth electrode pin 44 are arranged on the second terminal portion 220 constituting the other end portion in the longitudinal direction of the lighting cover 200.

  As shown in FIG. 1, the first electrode pins 41 to the fourth electrode pins 44 are disposed through the end surfaces of the first terminal portion 210 and the second terminal portion 220 in the longitudinal direction of the lighting cover 200. That is, one end of the first electrode pin 41 to the fourth electrode pin 44 is disposed so as to be exposed to the outside of the lighting cover 200. On the other hand, the other ends of the first electrode pins 41 to the fourth electrode pins 44 are exposed to the inside of the illumination cover 200 and are electrically connected to the light emitting circuit 10 and the rectifier circuit 20 disposed on the substrate 100. 1 shows an example in which the first terminal portion 210 and the second terminal portion 220 are wider in the direction perpendicular to the longitudinal direction than the central portion of the lighting cover 200. May be wider than the end, or may be the same width throughout the illumination cover 200.

  Further, at least one of the end portions of the first electrode pin 41 or the second electrode pin 42 exposed on the inner side of the lighting cover 200 and at least one of the end portions of the third electrode pin 43 or the fourth electrode pin 44, Each may be fixed to the substrate 100, thereby supporting the substrate 100 in the lighting cover 200. Or you may make it support the board | substrate 100 in the illumination cover 200 by the method of joining the periphery of the board | substrate 100 inside the illumination cover 200, etc. by another method.

  As shown in FIG. 2, the external dimensions of the light-emitting diode illuminating device 1, that is, the light-emitting diode illuminating device 1 can be attached to the existing fluorescent tube lighting device 300 by the first electrode pins 41 to the fourth electrode pins 44, that is, The length W and width D in the longitudinal direction, the arrangement of the first electrode pins 41 to the fourth electrode pins 44, and the like are the same as those of the conventional fluorescent tube. For example, the external dimensions of the light-emitting diode illuminating device 1 are set in accordance with the external dimensions of the fluorescent tube defined by the Japanese Industrial Standard (JIS). In particular, the shapes and structures of the first terminal portion 210 and the second terminal portion 220 corresponding to the fittings that are the attachment parts to the fluorescent tube lighting fixture 300 are compatible with the fittings of conventional fluorescent tubes. . Details of the fluorescent tube lighting apparatus 300 will be described later.

  FIG. 3 shows an example of the structure of the light-emitting diode illuminating device 1 as seen from a plane that passes through the first terminal portion 210 and is perpendicular to the longitudinal direction. Here, in the light-emitting diode illuminating device 1, for example, the first terminal portion 210 and the second terminal portion 220 corresponding to the fitting are G13 type, and the illumination cover 200 has a tube shape with a diameter φ26. In order to release heat generated from the light emitting diodes 11 to 1n and the like disposed on the surface of the substrate 100, as shown in FIG. 3, heat dissipation made of aluminum (Al) or the like on the back surface of the substrate 100 facing the surface. A plate 110 may be disposed.

  The illumination cover 200 of the light-emitting diode illuminating device 1 can employ a material that allows the emitted light from the light-emitting diodes 11 to 1n to pass therethrough. For example, the illumination cover 200 is formed of silicon resin, acrylic resin, polycarbonate resin, or the like. The illumination cover 200 protects the light emitting diodes 11 to 1 n and the like disposed on the substrate 100 and diffuses the light emitted from the light emitting diodes 11 to 1 n and outputs the diffused light to the outside of the light emitting diode illumination device 1. For this reason, light with high directivity emitted from each of the light emitting diodes 11 to 1n can be uniformly irradiated over a wide area from the light emitting diode illumination device 1. Moreover, the light emitted from the light emitting diode illumination device 1 can be adjusted to a desired color by applying a phosphor to the illumination cover 200. Various shapes can be adopted as the outer shape of the illumination cover 200, and for example, it may be a prismatic shape or a cylindrical shape.

  For the substrate 100, for example, a printed circuit board such as an aluminum plate can be employed. The first electrode pins 41 to the fourth electrode pins 44, the light emitting circuit 10, and the rectifying circuit 20 are electrically connected to each other by a wiring pattern, a wire wiring, or the like formed on the substrate 100.

  As shown in FIG. 1, the rectifier circuit 20 is a rectifier bridge diode having diodes D21 to D24. The rectifier circuit 20 receives and outputs an alternating current terminal ac1 that is a connection point between the cathode of the diode D21 and the anode of the diode D23, and an alternating current terminal ac2 that is a connection point between the anode of the diode D22 and the diode D24. Is full-wave rectified and output. The rectified output is supplied from a DC terminal dc1 which is a connection point between the cathode of the diode D21 and the cathode of the diode D22, and a DC terminal dc2 which is a connection point between the anode of the diode D23 and the anode of the diode D24. Note that the DC terminal dc1 has a positive potential and the DC terminal dc2 has a negative potential.

  As shown in FIG. 1, the AC terminal ac <b> 1 of the rectifier circuit 20 is connected to the first electrode pin 41 and the second electrode pin 42, and the AC terminal ac <b> 2 is connected to the third electrode pin 43 and the fourth electrode pin 44. The DC terminal dc1 is connected to the input terminal P101 of the light emitting circuit 10, and the DC terminal dc2 is connected to the output terminal P102 of the light emitting circuit 10.

  Here, the fluorescent tube lighting apparatus 300 will be described. The fluorescent tube lighting fixture 300 is an inverter type fluorescent tube lighting fixture as shown in FIG. 2, for example. A fluorescent tube lighting apparatus 300 shown in FIG. 2 includes a power source 310, an electronic circuit 320, and a resonant capacitor 330. The electronic circuit 320 rectifies and smoothes, for example, 50 Hz or 60 Hz AC power supplied from the power supply 310, and then converts it to high frequency AC power of, for example, about 20000 to 50000 Hz. Supply. The resonance capacitor 330 is a resonance capacitor for configuring a resonance circuit to realize an inverter operation, and further, by providing the resonance capacitor 330, an effect of noise removal is also achieved. The frequency of the high frequency AC power is determined by the value of the resonance capacitor 330.

  When the light-emitting diode illuminating device 1 shown in FIG. 1 is attached to the fluorescent tube lighting fixture 300 as shown in FIG. 2, for example, the first electrode pin 41 and the third electrode pin 43 are connected to the electronic circuit 320. At the same time, the second electrode pin 42 is connected to one electrode of the resonance capacitor 330, and the fourth electrode pin 44 is connected to the other electrode of the resonance capacitor 330. The first electrode pin 41 and the third electrode pin 43 may be connected to the resonance capacitor 330, and the second electrode pin 42 and the fourth electrode pin 44 may be connected to the electronic circuit 320. However, the light emitting diode illumination device 1 is mounted on the fluorescent tube lighting device 300 so that the light emitted from the light emitting diodes 11 to 1n is emitted from the light emitting diode illumination device 1 in a desired direction.

  An example of the operation of the light-emitting diode illuminating device 1 attached to the fluorescent tube illumination fixture 300 will be described below.

  When current flows from the first electrode pin 41 or the second electrode pin 42, the current flows to the light emitting circuit 10 via the DC terminal dc1 and the input terminal P101 via the diode D21. Then, the current flowing out from the light emitting circuit 10 flows through the output terminal P102 and the DC terminal dc2, and then flows to the third electrode pin 43 and the fourth electrode pin 44 through the diode D24.

  On the other hand, when a current flows from the third electrode pin 43 or the fourth electrode pin 44, the current flows to the light emitting circuit 10 via the DC terminal dc1 and the input terminal P101 via the diode D22. The current flowing out of the light emitting circuit 10 flows through the output terminal P102 and the DC terminal dc2, and then flows to the first electrode pin 41 and the second electrode pin 42 through the diode D23.

  As described above, even when AC power is applied between the first electrode pin 41 and the third electrode pin 43, AC power is applied between the second electrode pin 42 and the fourth electrode pin 44. Even so, the AC power output from the fluorescent tube lighting fixture 300 is full-wave rectified by the rectifier circuit 20, and a direct current is supplied to the light emitting circuit 10. For this reason, the light emitting diodes 11 to 1n can emit light. That is, the light-emitting diode illuminating device 1 attached to the fluorescent tube lighting fixture 300 is supported by the fluorescent tube lighting fixture 300 and emits light by the electric power supplied from the fluorescent tube lighting fixture 300.

  In addition, it is preferable that the number of light emitting diodes connected in series of the light emitting diodes 11 to 1n included in the light emitting circuit 10 is set according to the AC voltage Vf supplied by the fluorescent tube lighting apparatus 300. For example, when an AC voltage Vf is applied between the first electrode pin 41 and the third electrode pin 43, a voltage generated between the input terminal P101 and the output terminal P102 is used as a desired anode-cathode voltage of the light emitting diodes 11 to 1n. The number of the light emitting diodes 11 to 1n included in the light emitting circuit 10 connected in series is set so as to be substantially equal to the value divided by. Of course, a plurality of light emitting diode arrays in which the set number is connected in series may be connected in parallel between the input terminal P101 and the output terminal P102.

  In the above, the case where the fluorescent tube lighting apparatus 300 is an inverter type has been exemplarily described. However, in the case where the fluorescent lamp lighting apparatus 300 supplies AC power between the first electrode pin 41 and the third electrode pin 43, between the second electrode pin 42 and the fourth electrode pin 44, etc. by a method other than the inverter method. Even if it exists, the light-emitting-diode illuminating device 1 can be mounted | worn with and used for the lighting fixture 300 for fluorescent tubes. For example, even when the fluorescent lamp lighting device 300 is a glow lamp lighting method or a rapid start method, the light-emitting diode illuminating device 1 attached to the fluorescent tube lighting device 300 can emit light.

  As described above, according to the light-emitting diode illuminating device 1 according to the first embodiment of the present invention, the light-emitting diode illuminating device 1 is attached to the existing fluorescent tube lighting fixture 300 instead of the conventional fluorescent tube, The light emitting diodes 11 to 1n can emit light. That is, there is provided the light-emitting diode illuminating device 1 that can be used by being mounted on the existing fluorescent tube lighting device 300 without modifying the fluorescent tube lighting device 300 and the increase in the number of circuits is suppressed.

(Second Embodiment)
As shown in FIG. 4, the light-emitting diode illuminating device 1 according to the second embodiment of the present invention further includes a smoothing capacitor 50 connected between the input terminal P101 and the output terminal P102 of the light-emitting circuit 10. 1 is different from the light-emitting diode illuminating device 1 shown in FIG. One electrode of the smoothing capacitor 50 is connected to the anode of the light emitting diode 11, and the other electrode is connected to the cathode of the light emitting diode 1n. That is, the light emitting diodes 11 to 1n and the smoothing capacitor 50 are connected in parallel. Other configurations are the same as those of the first embodiment shown in FIG.

  Usually, the current IF flowing through the light emitting diode is proportional to the luminance Iv of the light emitted from the light emitting diode. However, in general, the ratio of the luminance Iv to the current IF (hereinafter referred to as “light emission efficiency”) decreases as the current IF increases due to the influence of heat generation of the light emitting diode.

  FIG. 5 shows a comparative example of the theoretical IF-Iv characteristic (hereinafter referred to as “theoretical characteristic”) G1 of the light emitting diode and the actually measured IF-Iv characteristic (hereinafter referred to as “measured characteristic”) G2. Indicates. As shown in FIG. 5, as the current IF increases, the increase rate of the luminance Iv with respect to the increase rate of the current IF of the actual measurement characteristic G2 decreases, and the difference between the theoretical characteristic G1 and the actual measurement characteristic G2 increases. Therefore, the actual current IF for obtaining the desired luminance Iv becomes larger than the theoretical value, and power consumption is wasted.

  However, the light emission efficiency can be improved by causing the light emitting diode to emit light with the current IF1 in which the theoretical characteristic G1 and the measured characteristic G2 match. At this time, the luminance Iv1 at the current IF1 is lower than the luminance Iv2 at the current IF2. However, by increasing the number of light emitting diodes through which the current IF1 flows, the luminance of the entire light emitting diode illumination device can be set to a desired luminance.

  That is, the number of the light emitting diodes 11 to 1n included in the light emitting circuit 10 by adopting a current value with higher light emission efficiency than the case where the number of the light emitting diodes 11 to 1n included in the light emitting circuit 10 is decreased by increasing the current value. The power consumption of the light-emitting diode illuminating device 1 for realizing the same luminance can be reduced when the number is increased.

  However, the current waveform rectified by the rectifier circuit 20 is usually a triangular waveform shown in FIG. For this reason, it is necessary to convert the triangular waveform into, for example, a rectangular waveform as shown in FIG. 6 in order to always pass a current with high luminous efficiency to the light emitting diodes 11 to 1n. At this time, in order to make the average current value the same before and after the waveform conversion, for example, the current IF may be integrated by a capacitor or the like.

  The light-emitting diode illuminating device 1 shown in FIG. 4 includes the smoothing capacitor 50 connected between the input terminal P101 and the output terminal P102. Therefore, the triangular waveform current output from the rectifier circuit 20 is smoothed and the light-emitting diode It flows to 11-1n. For this reason, the optimal electric current with high light emission efficiency can always be sent through the light emitting diodes 11-1n. It is preferable that the current value passed through the light emitting diodes 11 to 1n be the largest current value in a range where the theoretical characteristic G1 and the actual measurement characteristic G2 coincide. The capacitance value of the smoothing capacitor 50 is set according to a desired current value flowing through the light emitting diodes 11 to 1n, an AC voltage supplied from the fluorescent tube lighting device 300, and the like. For example, when the fluorescent tube lighting apparatus 300 supplies an AC voltage of 100V, the rectified DC voltage is about 250V. At this time, for example, a film capacitor of about 0.47 μF can be used as the smoothing capacitor 50.

  FIG. 7 shows an example in which the waveform of the current flowing through the light emitting diodes 11 to 1n in the light emitting diode illumination device 1 that does not use the smoothing capacitor 50 is measured. Here, it is assumed that the light emitting circuit 10 has a structure in which six light emitting diode rows in which the light emitting diodes 11 to 1n are connected in series are connected in parallel. At this time, the current value of the entire light emitting circuit 10 was 1.06 A at the peak, and the illuminance was 350 lux. That is, each peak current of the light emitting diodes 11 to 1n is about 177 mA which is 1/6 of 1.06 A, and the average current is about 33 mA. The power consumption is 74W. The number of light emitting diodes constituting the light emitting diode array is about 44 to 88 for one light emitting diode array, and about 150 to 450 for the entire light emitting circuit 10.

  FIG. 8 shows an example in which the waveform of the current flowing through the light emitting diodes 11 to 1n is measured when the 0.22 μF smoothing capacitor 50 is connected to the light emitting diode illumination device 1 in which the triangular waveform current IF shown in FIG. 7 is measured. Indicates. As shown in FIG. 8, the current waveform flowing through the light emitting diodes 11 to 1n is smoothed. At this time, the current value of the entire light emitting circuit 10 was 0.28 A at the peak, and the illuminance was 390 lux. Each peak current of the light emitting diodes 11 to 1n is about 47 mA, and the average current is about 28 mA. The power consumption is 58W.

  As shown in FIGS. 7 and 8, the smoothing capacitor 50 is connected between the input terminal P101 and the output terminal P102 of the light emitting circuit 10, thereby suppressing the decrease in the illuminance of the light emitting diode illumination device 1 and the power consumption. Was reduced from 74W to 58W.

  As described above, in the light-emitting diode illuminating device 1 according to the second embodiment of the present invention, the current waveform flowing through the light-emitting diodes 11 to 1n is smoothed by the smoothing capacitor 50. By setting the capacitance value of the smoothing capacitor 50 so that the smoothed current value becomes a current value with high light emission efficiency of the light emitting diodes 11 to 1n, the decrease in illuminance of the light emitting diode lighting device 1 is suppressed and the consumption is reduced. Power can be reduced. Others are substantially the same as those in the first embodiment, and redundant description is omitted.

(Other embodiments)
As described above, the present invention has been described according to the first and second embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In the description of the first and second embodiments already described, the case where the outer shape of the light-emitting diode illuminating device 1 is the same as that of the straight tube fluorescent tube is shown. However, the outer shape of the light-emitting diode illuminating device 1 is a flat spiral. It may be a shape or a bulb shape.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

It is a schematic diagram which shows the structure of the light-emitting-diode illuminating device which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows the example which mounted | wore the inverter type fluorescent tube lighting fixture with the light-emitting-diode illuminating device which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows the structure seen from the end surface of the light emitting diode illuminating device which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows the structure of the light emitting diode illuminating device which concerns on the 2nd Embodiment of this invention. It is a graph which shows the relationship between the electric current of the light emitting diode of the light emitting diode illuminating device which concerns on the 2nd Embodiment of this invention, and a brightness | luminance. It is a graph which shows the example of a waveform before and behind the rectification of the electric current which flows into a light emitting diode. It is a graph which shows the example of a measurement of the waveform before the rectification of the current which flows into a light emitting diode. It is a graph which shows the measurement example of the waveform of the electric current which flows into the light emitting diode of the light emitting diode illuminating device which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Light emitting diode illuminating device 10 ... Light emitting circuit 11-1n ... Light emitting diode 20 ... Rectifier circuit 41 ... 1st electrode pin 42 ... 2nd electrode pin 43 ... 3rd electrode pin 44 ... 4th electrode pin 50 ... Smoothing capacitor 100 ... Substrate 110 ... Heat sink 200 ... Lighting cover 210 ... First terminal portion 220 ... Second terminal portion 300 ... Fluorescent tube lighting device 310 ... Power source 320 ... Electronic circuit 330 ... Resonance capacitor D21-D24 ... Diode

Claims (5)

A light emitting circuit including a light emitting diode;
An illumination cover in which the light emitting circuit is disposed inside and the light emitted from the light emitting diode is transmitted;
A first electrode pin and a second electrode pin arranged at one end in the longitudinal direction of the lighting cover and short-circuited to each other, and a first electrode pin and a second electrode pin arranged at the other end in the longitudinal direction of the lighting cover and short-circuited from each other. A three-electrode pin and a fourth electrode pin;
The AC power applied between the first electrode pin and the third electrode pin and the AC power applied between the second electrode pin and the fourth electrode pin are rectified to DC power, and the DC power is supplied to the light emitting diode. A light-emitting diode illuminating device comprising: a rectifying circuit to be supplied. The rectifier circuit is
A first AC terminal connected to the first electrode pin and the second electrode pin;
A second AC terminal connected to the third electrode pin and the fourth electrode pin;
A first DC terminal connected to the anode of the light emitting diode;
The light-emitting diode illuminating device according to claim 1, wherein the light-emitting diode illuminating device is a rectifier bridge diode including a second DC terminal connected to a cathode of the light-emitting diode. The rectifier circuit is
A first diode having an anode connected to the first AC terminal and a cathode connected to the first DC terminal;
A second diode having an anode connected to the second AC terminal and a cathode connected to the first DC terminal;
A third diode having an anode connected to the second DC terminal and a cathode connected to the first AC terminal;
The light emitting diode illuminating device according to claim 2, further comprising: a fourth diode having an anode connected to the second DC terminal and a cathode connected to the second AC terminal.   The light-emitting diode illuminating device according to any one of claims 1 to 3, wherein the light-emitting circuit includes a plurality of light-emitting diodes connected in series.   The light emitting diode illumination device according to claim 1, further comprising a smoothing capacitor disposed between an anode and a cathode of the light emitting diode.

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