JP2015185378A - Illumination system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination system capable of suppressing all of a plurality of illumination devices from turning off in the event of some failure and suppressing variations in the brightness of each of the illumination devices even when the plurality of illumination devices are connected with a controller.SOLUTION: The illumination system includes a controller and a plurality of illumination devices. The controller converts AC power into DC power to output DC power. The plurality of illumination devices are connected in series to the controller. Each of the plurality of illumination devices includes a light-emitting element and a resistive element connected in parallel to the light-emitting element.

Description

  Embodiments described herein relate generally to a lighting system.

  There is an illumination system that includes an illumination device and a control device that supplies electric power to the illumination device. For example, there is a low voltage halogen lamp that is lit at a voltage of about 12V as one of the lighting devices. The low voltage halogen lamp is connected to a control device called an electronic transformer. The electronic transformer converts AC100V commercial power to AC12V and supplies it to the low voltage halogen lamp.

  In the lighting device, for example, there is a movement to replace a low-voltage halogen lamp with a lamp using a light emitting element such as an LED for the purpose of reducing power consumption. When a lighting device using a light emitting element is connected to an electronic transformer, the operation of the electronic transformer becomes unstable, and for example, flickering or abnormal noise may occur. For this reason, it is considered to replace the electronic transformer with a control device corresponding to the light emitting element in accordance with the replacement of the lighting device.

  In such a lighting system, it is desired to connect a plurality of lighting devices to a control device. However, when a plurality of lighting devices are connected in series to the control device, all of the lighting devices are turned off when one of the lighting devices fails to open. In addition, when a plurality of lighting devices are connected in parallel to the control device, it is possible to suppress turning off at the time of failure, but it is difficult to control the current flowing through each lighting device. For example, the brightness varies among the lighting devices.

  For this reason, in a lighting system, even when a plurality of lighting devices are connected to a control device, it is desirable to suppress turning off of all lighting devices at the time of failure and to suppress variation in brightness of each lighting device. It is.

Japanese Utility Model Publication No. 5-78190

  The embodiment of the present invention provides an illumination system that can suppress the turn-off of all the illumination devices at the time of failure and suppress the variation in the brightness of each illumination device even when a plurality of illumination devices are connected to the control device. provide.

  According to the embodiment of the present invention, an illumination system including a control device and a plurality of illumination devices is provided. The control device converts AC power into DC power and outputs the DC power. The plurality of lighting devices are connected in series to the control device. Each of the plurality of lighting devices includes a light emitting element and a resistance element connected in parallel to the light emitting element.

  Even when a plurality of lighting devices are connected to the control device, it is possible to provide a lighting system that can suppress the turn-off of all the lighting devices at the time of failure and can suppress variations in brightness of each lighting device.

1 is a block diagram schematically illustrating an illumination system according to a first embodiment. It is a block diagram showing typically the lighting installation concerning a 1st embodiment. Fig.3 (a)-FIG.3 (c) are the schematic diagrams showing the illuminating device which concerns on 1st Embodiment. It is a block diagram showing typically an example of a control device concerning a 1st embodiment. FIG. 5A and FIG. 5B are schematic views showing a part of another illumination device according to the first embodiment. It is a block diagram showing typically another illuminating device concerning a 1st embodiment. It is a block diagram which represents typically the illumination system which concerns on 2nd Embodiment. It is a block diagram which represents typically the illuminating device which concerns on 2nd Embodiment. It is a block diagram showing typically an example of a control device concerning a 2nd embodiment.

Each embodiment will be described below with reference to the drawings.
The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between the parts, and the like are not necessarily the same as actual ones. Further, even when the same part is represented, the dimensions and ratios may be represented differently depending on the drawings.
Note that, in the present specification and each drawing, the same elements as those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

(First embodiment)
FIG. 1 is a block diagram schematically illustrating an illumination system according to the first embodiment.
As illustrated in FIG. 1, the lighting system 10 includes a plurality of lighting devices 12 and a control device 14. The control device 14 is electrically connected to each of the lighting devices 12. In this example, each of the lighting devices 12 is connected in series to the control device 14.

  The control device 14 is electrically connected to the AC power supply 4. The AC power supply 4 supplies, for example, 100 V (effective value) AC power to the control device 14. The AC power source 4 is, for example, a commercial power source or a private generator. The control device 14 converts AC power supplied from the AC power supply 4 into DC power. The control device 14 converts AC power into DC power corresponding to each lighting device 12. Then, the control device 14 outputs the converted DC power to each lighting device 12. Each lighting device 12 is lit in response to the supply of DC power from the control device 14.

  The lighting device 12 includes a light emitting element 20 and a resistance element 22. For example, a light emitting diode (LED) is used for the light emitting element 20. The illumination device 12 is, for example, an LED lamp. The light emitting element 20 is not limited to an LED, and may be, for example, an organic light emitting diode (OLED) or a laser diode.

  The resistance element 22 is connected to the light emitting element 20 in parallel. The resistance value of the resistance element 22 is higher than the resistance value of the light emitting element 20 in the forward direction. More specifically, the resistance value of the resistance element 22 is higher than the forward resistance value of the light emitting element 20 in the extinguished state. The resistance value of the resistance element 22 is higher than the resistance value in the forward direction of the light emitting element 20 when no voltage is applied.

FIG. 2 is a block diagram schematically illustrating the lighting device according to the first embodiment.
As illustrated in FIG. 2, the lighting system 10 further includes a socket 16, for example. The socket 16 is electrically connected to the control device 14. The lighting device 12 is electrically connected to the control device 14 via the socket 16. Therefore, in this example, a plurality of sockets 16 corresponding to each of the plurality of lighting devices 12 are provided in the lighting system 10. The lighting device 12 is detachably connected to the control device 14 via a socket 16. The lighting device 12 may be directly connected to the control device 14 via, for example, wiring. That is, the electrical connection between the lighting device 12 and the control device 14 is not limited to the socket 16. The socket 16 is provided as necessary and can be omitted.

  The illumination device 12 includes a base 30 (connection unit) and a light emitting unit 32. The base 30 is used for electrical connection with the control device 14. The lighting device 12 is electrically connected to the control device 14 via the base 30. The base 30 has a pair of pins 30a and 30b (first and second fitting portions). The pair of pins 30a and 30b have substantially the same size such as length and diameter.

  The base 30 is detachably held in the socket 16. The socket 16 has a pair of holes 16a and 16b (first and second fitted portions). The shape of each hole 16a, 16b corresponds to the shape of each pin 30a, 30b. Each pin 30a, 30b is inserted into each hole 16a, 16b. Thereby, the illumination device 12 is electrically connected to the control device 14.

  Each pin 30a, 30b can be reversibly connected to the holes 16a, 16b. That is, the pin 30a can be connected to one of the holes 16a and 16b, and the pin 30b can be connected to the other of the holes 16a and 16b in a state where the pin 30a is connected. As described above, the lighting device 12 is mechanically held in the socket 16 by the base 30 and is electrically connected to the socket 16 by the base 30.

  In addition, the 1st, 2nd fitting part and the 1st, 2nd to-be-fitted part are not restricted to the above-mentioned example. However, the first and second fitting portions have shapes that can be reversibly connected to the first and second fitted portions. Thereby, for example, the lighting device 12 can be easily attached to the socket 16. For example, the first and second fitted parts may be concave parts.

  The light emitting unit 32 includes the light emitting element 20. The light emitting unit 32 causes the light emitting element 20 to emit light by DC power input via the base 30. For example, the light emitting unit 32 includes a plurality of light emitting elements 20. In this example, eight light emitting elements 20 are provided. In this example, four light emitting elements 20 are connected in series. And four light emitting elements 20 connected in series are connected in parallel. The connection of each light emitting element 20 may be arbitrary. For example, each light emitting element 20 may be connected in series, or each light emitting element 20 may be connected in parallel. Moreover, the number of each light emitting element 20 may be arbitrary. For example, the number of the light emitting elements 20 may be one.

  The light emitting unit 32 includes a first terminal 32a and a second terminal 32b. For example, of the four light emitting elements 20 connected in series, the anode of the first light emitting element 20 is electrically connected to the first terminal 32a, and the cathode of the last light emitting element 20 is electrically connected to the second terminal 32b. Connected. Thereby, when a current flows in one direction from the first terminal 32a to the second terminal 32b, each light emitting element 20 is turned on. In addition, the 1st terminal 32a and the 2nd terminal 32b may be the arbitrary electrical connection points which can send an electric current to each light emitting element 20 connected in series or in parallel. For example, of the four light emitting elements 20 connected in series, the anode of the first light emitting element 20 may be the first terminal 32a, and the cathode of the last light emitting element 20 may be the second terminal 32b.

  The resistance element 22 is connected to the light emitting unit 32 in parallel. That is, the resistance element 22 is connected in parallel to each of the plurality of light emitting elements 20. In this case, the resistance value of the resistance element 22 is higher than the combined resistance value in the forward direction of the plurality of light emitting elements 20.

  The lighting device 12 further includes a rectifier 24. The rectifier 24 is electrically connected between the base 30 and the light emitting unit 32. The rectifier 24 rectifies the current flowing through the light emitting unit 32 in one direction from the first terminal 32a toward the second terminal 32b. That is, the rectifier 24 rectifies the current flowing through the light emitting unit 32 in the forward direction of each light emitting element 20. The rectifier 24 rectifies the current flowing through each light emitting element 20 in one direction in which each light emitting element 20 is lit. Thereby, even when each pin 30a, 30b can be reversibly connected to each hole 16a, 16b, it is possible to suppress the voltage from being applied to each light emitting element 20 in the opposite direction. For example, failure of each light emitting element 20 can be suppressed. The rectifier 24 is provided as necessary and can be omitted.

  The rectifier 24 is a bridge circuit including four diodes 24d (rectifier elements), for example. As the rectifier 24, for example, a diode in which four diodes 24d are contained in one package may be used, or four diodes 24d may be combined. The rectifier 24 is not limited to a bridge circuit using the four diodes 24d, and may be any circuit that can rectify the current flowing through each light emitting element 20.

  The first terminal 32a is at least electrically connected to one of the pins 30a and 30b. The second terminal 32b is at least electrically connected to the other of the pins 30a and 30b. In this example, each of the first terminals 32 a and 32 b is electrically connected to each of the pins 30 a and 30 b via the rectifier 24. When the rectifier 24 is omitted, for example, the first terminal 32a is electrically connected to the pin 30a, and the second terminal 32b is electrically connected to the pin 30b.

  The lighting device 12 does not include a power supply circuit (power conversion circuit) such as a chopper circuit. For this reason, in the illuminating device 12, the DC power supplied from the control device 14 is directly input to the light emitting unit 32. In other words, a voltage that is substantially the same as the voltage of the DC power output from the control device 14 is applied between the first terminal 32a and the second terminal 32b, excluding losses due to wiring and the like.

Fig.3 (a)-FIG.3 (c) are the schematic diagrams showing the illuminating device which concerns on 1st Embodiment.
FIG. 3A is a perspective view schematically showing the appearance of the lighting device 12. FIG. 3B is a side view schematically showing the appearance of the illumination device 12. FIG. 3C is a schematic cross-sectional view illustrating a part of the lighting device 12 in an enlarged manner.
As illustrated in FIG. 3A to FIG. 3C, the lighting device 12 includes a case 34 and a substrate 35. FIG. 3C schematically shows a cross section of the case 34. The case 34 has, for example, a bowl shape. The case 34 has, for example, a paraboloid inner surface 34a and an opening 34b. In other words, the opening 34b is an open end of the inner surface 34a. The base 30 is provided, for example, on the outer surface opposite to the opening 34 b of the case 34.

  Each light emitting element 20 is provided on the substrate 35. The substrate 35 has a wiring pattern (not shown). Each light emitting element 20 is mounted on the substrate 35 by being disposed so as to be in contact with the wiring pattern.

  The substrate 35 is provided inside the case 34. The board | substrate 35 is disk shape, for example. The substrate 35 has a front surface 35a and a back surface 35b opposite to the front surface 35a. The substrate 35 is attached to the inside of the case 34 with the surface 35a facing the opening 34b, for example. Each light emitting element 20 is provided on the surface 35a. For example, the light emitting elements 20 are arranged in a ring on the surface 35a. Arrangement of each light emitting element 20 may be arbitrary.

  The rectifier 24 is provided on the back surface 35 b of the substrate 35. The substrate 35 is a so-called double-sided mounting substrate. Thereby, it can suppress that the rectifier 24 is visible from the outside. For example, the design of the lighting device 12 can be improved.

  The case 34 is further provided with a cover 36 and a lens 38. The cover 36 closes the opening 34 b of the case 34. The cover 36 has a plate shape, for example. In this example, the cover 36 has a disk shape. The cover 36 has optical transparency with respect to light emitted from each light emitting element 20 (hereinafter referred to as emitted light). The cover 36 is transparent, for example. For the cover 36, for example, plastic or glass is used.

  A plurality of lenses 38 are provided corresponding to each of the light emitting elements 20. That is, in this example, eight lenses 38 are provided. Each lens 38 has optical transparency with respect to the light emitted from each light emitting element 20. Each lens 38 is transparent, for example. For each lens 38, for example, plastic or glass is used. Each lens 38 is provided between the substrate 35 and the cover 36, for example. Each lens 38 may be formed integrally with the cover 36, for example.

  Each lens 38 has a first end 38 a that faces the light emitting element 20, and a second end 38 b opposite to the first end 38 a. Each of the lenses 38 is disposed to face each of the light emitting elements 20. The light emitted from the light emitting element 20 is incident on the first end 38 a of the lens 38. For example, the lens 38 controls the light distribution angle of the emitted light by emitting the emitted light incident from the first end portion 38a from the second end portion 38b. For example, the lens 38 collects the emitted light. For example, the lens 38 sets the light distribution angle of the emitted light to a predetermined value or less. The lens 38 may be, for example, a lens that diverges emitted light.

  The first end portion 38 a of each lens 38 is provided with a recess 38 c that covers the light emitting element 20. Thereby, the incident efficiency of the emitted light to the lens 38 can be improved, for example. More specifically, the first end portion 38a faces the light emitting element 20 on the inner bottom surface of the recess 38c. The cover 36 and each lens 38 are provided as necessary and can be omitted.

  The case 34 is, for example, an MR16 type. The base 30 is, for example, a GU5.3 type. That is, the illumination device 12 is a so-called low voltage halogen lamp type LED lamp. The case 34 may be, for example, an AR111 type. The base 30 may be, for example, a G53 type. The shape of the case 34 and the shape of the base 30 may be any shape that complies with a low voltage halogen lamp type standard, for example.

FIG. 4 is a block diagram schematically illustrating an example of the control device according to the first embodiment.
As illustrated in FIG. 4, the control device 14 includes a conversion unit 14 a and a control unit 14 b. The conversion unit 14 a converts the AC power of the AC power supply 4 into DC power corresponding to the lighting device 12. The control unit 14b controls power conversion by the conversion unit 14a. The control unit 14b detects at least one of a current and a voltage of DC power. That is, the control unit 14b detects at least one of the output current and the output voltage of the conversion unit 14a. The control unit 14b controls the conversion of the conversion unit 14a based on at least one of the output current and the output voltage. That is, the control unit 14b performs feedback control on the conversion unit 14a based on the output of the conversion unit 14a.

  The conversion unit 14a includes, for example, a rectifier 50, a smoothing capacitor 51, a transformer 52, a switching element 53, a diode 54, an output capacitor 55, and a resistance element 56.

  The rectifier 50 is electrically connected to the AC power supply 4. The rectifier 50 converts the AC power of the AC power supply 4 into pulsating power. The rectifier 50 is, for example, a diode bridge. For example, the rectifier 50 rectifies all the AC power of the AC power supply 4. The rectifier 50 may be a half-wave rectifier or the like. The smoothing capacitor 51 smoothes the pulsating power output from the rectifier 50 and converts the pulsating power into DC power.

  The transformer 52 has a primary winding 52a and a secondary winding 52b. The switching element 53 includes a pair of main electrodes 53a and 53b and a control electrode 53c. For example, a power MOSFET is used for the switching element 53.

  One end of the primary winding 52 a of the transformer 52 is electrically connected to a high potential side terminal of the smoothing capacitor 51. The other end of the primary winding 52a is electrically connected to the main electrode 53a of the switching element 53. The main electrode 53 b of the switching element 53 is electrically connected to the low potential side terminal of the smoothing capacitor 51. The control electrode 53c of the switching element 53 is electrically connected to the control unit 14b. The controller 14b controls switching of the switching element 53. Thereby, the control part 14b controls the conversion of the electric power by the conversion part 14a.

  One end of the secondary winding 52 b of the transformer 52 is electrically connected to the anode of the diode 54. The cathode of the diode 54 is electrically connected to an electrode provided in the hole 16 a of the socket 16. That is, the cathode of the diode 54 is electrically connected to the pin 30 a of the base 30. The other end of the secondary winding 52 b is electrically connected to an electrode provided in the hole 16 b of the socket 16. That is, the other end of the secondary winding 52 b is electrically connected to the pin 30 b of the base 30. The output capacitor 55 is connected in parallel to the diode 54. The output capacitor 55 smoothes the power output from the secondary winding 52b and converts it into DC power.

  The resistance element 56 is connected to a terminal on the low potential side of the output capacitor 55. The resistance element 56 is provided between, for example, the low potential side terminal of the output capacitor 55 and the socket 16. The control unit 14 b is connected to one end of the resistance element 56. The control unit 14 b detects the current value of the DC power supplied to each lighting device 12 based on the voltage of the resistance element 56.

  The control unit 14 b converts the AC power of the AC power supply 4 into DC power corresponding to each lighting device 12 by switching of the switching element 53. Further, the control unit 14b performs feedback control of switching of the switching element 53 so that the current flowing through each lighting device 12 becomes substantially constant based on the detected current value. Thereby, the variation in the brightness of each illuminating device 12 can be suppressed. That is, in this example, the control device 14 is a so-called constant current circuit.

  When performing constant current control as described above, the output voltage of the conversion unit 14a varies depending on the number of lighting devices 12 connected in series. The output voltage of the conversion part 14a becomes high, so that the number of the illuminating devices 12 connected in series increases. For this reason, the control unit 14b determines the voltage value of the DC power to be output based on the detected current value, the switching frequency of the switching element 53, and the like, and when the voltage value of the DC power becomes 120V or higher, Stop power output. For example, the control unit 14b stops switching of the switching element 53 when the voltage value of the DC power becomes 120V or more.

  For example, the control unit 14b sets the voltage per one lighting device 12 to about 12V. In this case, the control unit 14b stops the output of DC power when ten or more lighting devices 12 are connected in series.

  In this example, the converter 14a is a so-called isolated flyback DC-DC converter. The configuration of the conversion unit 14a is not limited to the above, and may be any configuration that can convert AC power into DC power. The current value of the DC power is not limited to the above, and may be detected from the primary side of the transformer 52, for example.

  As described above, the control device 14 is designed to be suitable for the lighting device as in the present embodiment, and does not include an electronic transformer. The illuminating device 12 is mainly designed as a light source that is electrically connected to the control device 14 that outputs DC power without including an electronic transformer by fitting the base 30 to the socket 16. For example, the control device 14 sets the pin 30b to a common potential (for example, ground potential), and sets the pin 30a to a potential higher than the common potential. Thereby, a forward voltage is applied to each light emitting element 20, and each light emitting element 20 lights up.

  In the field of lighting, there is a movement to replace low-voltage halogen lamps and the like with lighting devices using light emitting elements such as LEDs. An electronic transformer used for a low-voltage halogen lamp has a characteristic that its operation is not stable unless a certain amount of current flows. An illumination device using a light emitting element such as an LED consumes less power than a low-voltage halogen lamp. Moreover, the illumination device as in the present embodiment does not include a power supply circuit or the like. For this reason, in the lighting device, a necessary current cannot be passed, and the operation of the electronic transformer may become unstable. For example, the output of the electronic transformer becomes intermittent, and flicker and noise occur. For this reason, when the low voltage halogen lamp is replaced with a lighting device, it is necessary to replace the electronic transformer for the low voltage halogen lamp with a control device for the lighting device.

  In such a lighting system, a plurality of lighting devices may be connected in series. When a plurality of lighting devices are connected in series, variation in brightness of each lighting device can be suppressed by performing constant current control. On the other hand, when one of the light emitting elements of each lighting device has an open failure, all the lighting devices are turned off.

  On the other hand, in the illumination system 10 according to the present embodiment, the resistance element 22 is connected in parallel to the light emitting element 20 in each of the illumination devices 12. Thereby, even when the light emitting element 20 has an open failure, it is possible to suppress the current from flowing through the resistance element 22 and turning off all the lighting devices 12. Therefore, in the lighting system 10 according to the present embodiment, even when a plurality of lighting devices 12 are connected in series to the control device 14, the lighting devices 12 are prevented from being turned off at the time of failure, and each lighting device 12. Variation in brightness can be suppressed.

  In the illumination system 10, the resistance value of the resistance element 22 is set higher than the resistance value of the light emitting element 20 in the forward direction. Thereby, for example, a current can be appropriately passed through the light emitting element 20 at normal times. For example, abnormal heating of the light emitting element 20 can be suppressed.

  In the lighting system 10, when the voltage value of the DC power becomes 120 V or more, the control unit 14 b of the control device 14 stops the output of the DC power. That is, in the lighting system 10, the voltage value of the DC power is prevented from exceeding the special low voltage defined by IEC60598-1. Thereby, for example, even when an electric shock occurs due to replacement of the lighting device 12, the influence of the voltage on the human body can be suppressed.

FIG. 5A and FIG. 5B are schematic views showing a part of another illumination device according to the first embodiment.
FIG. 5A is a cross-sectional view schematically showing a part of the lighting device 12, and FIG. 5B is a plan view schematically showing the substrate 35.
As shown in FIG. 5A and FIG. 5B, in this example, each diode 24 d of the rectifier 24 is provided on the surface 35 a of the same substrate 35 as each light emitting element 20.

  Each diode 24d is disposed at a position that does not face the first end portion 38a of each lens 38 in a direction perpendicular to the surface 35a. Thereby, each diode 24d can be made difficult to see in, for example, a light-off state. Thereby, the designability of the illuminating device 12 can be improved, for example.

  Each lens 38 has an optical axis OA. The optical axis OA is, for example, a direction from the first end 38a toward the second end 38b. In this example, the optical axis OA is substantially the same as the direction perpendicular to the surface 35a. In each lens 38, the width of the second end portion 38b is wider than the width of the first end portion 38a. Here, the “width” is a length in a direction perpendicular to the optical axis OA. In other words, it is the length in the direction parallel to the surface 35a. For example, the width of the lens 38 increases in the direction from the first end 38a toward the second end 38b. That is, the width of the lens 38 increases in the direction in which the emitted light is irradiated.

  Each diode 24d is arranged at a position that does not overlap the first end portion 38a of the lens 38 and at least a portion thereof overlaps the second end portion 38b in a direction perpendicular to the surface 35a. That is, at least a part of the diode 24d is covered with the lens 38 in the direction perpendicular to the surface 35a. Thereby, each diode 24d can be made harder to see from the outside. Thus, the position of the rectifier 24 is not limited to the back surface 35b side of the substrate 35, and may be an arbitrary position that does not face the first end portion 38a of each lens 38.

FIG. 6 is a block diagram schematically illustrating another illumination device according to the first embodiment.
As illustrated in FIG. 6, in this example, the lighting device 12 includes a current limiting element 26. The current limiting element 26 limits the current flowing through each light emitting element 20. In other words, the current limiting element 26 suppresses an overcurrent from flowing through each light emitting element 20. Thereby, for example, each light emitting element 20 can be protected from overcurrent or the like.

  The current limiting element 26 is connected in series to the light emitting unit 32, for example, and opens a path through which a current flows to each light emitting element 20. The current limiting element 26 is, for example, a current fuse. The current limiting element 26 is not limited to this, and may be a circuit using a switching element, for example.

  The resistance element 22 is connected in parallel to the current limiting element 26 and the light emitting unit 32. Thereby, for example, in one lighting device 12, even after the current limiting element 26 opens a path through which a current flows to each light emitting element 20, the other lighting devices 12 connected in series are connected via the resistance element 22. Current flows. Thereby, it can suppress that all the illuminating devices 12 turn off after the current limiting element 26 operate | moves. For example, even after the current limiting element 26, which is a current fuse, is blown, it is possible to prevent all the lighting devices 12 from being turned off.

(Second Embodiment)
FIG. 7 is a block diagram schematically illustrating an illumination system according to the second embodiment.
As illustrated in FIG. 7, the lighting system 100 includes a plurality of lighting devices 112 and a control device 114. In the lighting system 100, a plurality of lighting devices 112 are connected in parallel to the control device 114. Note that in the present embodiment, components that are substantially the same in function and configuration as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the lighting system 100, each of the lighting devices 112 includes a light emitting element 20 and a current control circuit 120. The current control circuit 120 controls the current flowing through the light emitting element 20. For example, the current control circuit 120 makes the current flowing through the light emitting element 20 substantially constant.

FIG. 8 is a block diagram schematically illustrating a lighting device according to the second embodiment.
As illustrated in FIG. 8, the current control circuit 120 includes, for example, a transistor 121 and resistance elements 122 to 124. In this example, the transistor 121 is an NPN transistor. The transistor 121 is not limited to this, and may be, for example, an FET.

  The resistance elements 122 and 123 are connected in series between the output terminals of the rectifier 24. The base of the transistor 121 is connected between the resistance elements 122 and 123. The collector of the transistor 121 is connected to the second terminal 32 b of the light emitting unit 32. The emitter of the transistor 121 is connected to one end of the resistance element 124. The other end of the resistance element 124 is connected to the low potential output terminal of the rectifier 24.

  Accordingly, a substantially constant current corresponding to the base voltage of the transistor 121 flows through each light emitting element 20. The configuration of the current control circuit 120 is not limited to the above, and may be any configuration that allows a substantially constant current to flow through each light emitting element 20.

FIG. 9 is a block diagram schematically illustrating an example of a control device according to the second embodiment.
As illustrated in FIG. 9, the control device 114 includes a conversion unit 114a and a control unit 114b, as in the first embodiment. The conversion unit 114a includes resistance elements 57 and 58 instead of the resistance element 56 of the conversion unit 14a of the first embodiment.

  The resistance elements 57 and 58 are connected in parallel to the output capacitor 55 while being connected in series with each other. The control unit 114b is connected between the resistance elements 57 and 58. As a result, a voltage obtained by dividing the voltage of the DC power by the resistance elements 57 and 58 is input to the control unit 114b. The control unit 114b detects the voltage value of the DC power supplied to each lighting device 12 based on the divided voltage of the resistance elements 57 and 58.

  Based on the detected voltage value, the control unit 114b performs feedback control of switching of the switching element 53 so that the voltage supplied to each lighting device 12 is substantially constant. That is, in this example, the control device 114 is a so-called constant voltage circuit. At this time, the control unit 114b sets the voltage value of the DC power to 120V or less. Thereby, as mentioned above, the influence of the voltage on the human body at the time of electric shock can be suppressed.

  In an illumination system, a plurality of illumination devices may be connected in parallel. When a plurality of lighting devices are connected in parallel, even when any of the light emitting elements of each lighting device has an open failure, it is possible to prevent all the lighting devices from being turned off. On the other hand, when the lighting devices are connected in parallel, it becomes difficult to control the current flowing through the lighting devices. For example, the brightness of each lighting device varies.

  On the other hand, in the illumination system 100 according to the present embodiment, the current control circuit 120 is provided in each illumination device 112. Thereby, for example, the current flowing through each light emitting element 20 of each lighting device 112 can be made substantially constant. For example, variation in brightness of each lighting device 112 can be suppressed. Therefore, in the lighting system 100 according to the present embodiment, even when a plurality of lighting devices 112 are connected to the control device 114 in parallel, turning off of all the lighting devices 112 at the time of failure is suppressed, and each lighting device 112 is controlled. Variation in brightness can be suppressed.

  In each of the above-described embodiments, a lighting device that has a base 30 and receives power supply from the outside through the base 30 is shown. That is, in each of the above embodiments, a so-called illumination lamp is shown as the illumination device. The lighting device is not limited to a lamp, and may be, for example, a lighting module that receives external power supply via wiring. That is, the connection part for electrically connecting to the control devices 14 and 114 may be wiring. When the lighting device is a lighting module, the electrical connection between the lighting device and the control devices 14 and 114 may be performed, for example, via a terminal block. The lighting system may include, for example, a lighting device (lighting module), a control device, and a terminal block.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  4 ... AC power supply 10, 100 ... Illumination system 12, 112 ... Illumination device 14, 114 ... Control device, 14a, 114a ... Conversion unit, 14b, 114b ... Control unit, 16 ... Socket, 20 ... Light emitting element, 22 DESCRIPTION OF SYMBOLS ... Resistance element, 24 ... Rectifier, 24d ... Diode, 26 ... Current limiting element, 30 ... Base, 32 ... Light emitting part, 34 ... Case, 35 ... Substrate, 36 ... Cover, 38 ... Lens, 50 ... Rectifier, 51 ... Smooth Capacitor 52 ... Transformer 53 ... Switching element 54 ... Diode 55 ... Output capacitor 56-58 ... Resistance element 120 ... Current control circuit 121 ... Transistor 122-124 ... Resistance element

Claims (7)

A control device that converts AC power into DC power and outputs the DC power;
A plurality of lighting devices connected in series to the control device;
With
Each of the plurality of lighting devices includes a light emitting element and a resistance element connected in parallel to the light emitting element.   The illumination system according to claim 1, wherein a resistance value of the resistance element is higher than a resistance value in a forward direction of the light emitting element.   The lighting system according to claim 1, wherein the plurality of lighting devices further include a rectifier that rectifies a current flowing through the light emitting element in a forward direction of the light emitting element.   The illumination system according to any one of claims 1 to 3, wherein the plurality of illumination devices further include a current limiting element that limits a current flowing through the light emitting element. The controller is
A converter for converting the AC power into the DC power;
A control unit that controls the conversion of the conversion unit based on at least one of the current and voltage of the DC power;
Including
The said control part is an illumination system as described in any one of Claims 1-4 which stops the output of the said DC power, when the voltage value of the said DC power becomes 120V or more. A control device that converts AC power into DC power and outputs the DC power;
A plurality of lighting devices connected in parallel to the control device;
With
Each of the plurality of lighting devices includes a light emitting element and a current control circuit that controls a current flowing through the light emitting element. The controller is
A converter for converting the AC power into the DC power;
Based on at least one of the current and voltage of the DC power, a control unit that controls the conversion of the conversion unit so that the voltage of the DC power becomes constant;
The lighting system according to claim 6.

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