Lighting system

Abstract

Reduces overall power loss in the system. [Solution] The lighting system 10 comprises a power supply unit 1 and a plurality of light source units 2 connected to each other via a power line PL1. The power supply unit 1 has a conversion unit 12 and a control unit 13. The conversion unit 12 converts the AC voltage supplied from an external power supply PS1 into a DC voltage. The control unit 13 controls the conversion unit 12. Each of the plurality of light source units 2 has a light source 21 and a constant current circuit 22. The light source 21 is supplied with a DC voltage from the conversion unit 12 via the power line PL1. The constant current circuit 22 controls the current flowing through the light source 21.

Description

Technical Field

[0005]

[0001] The present disclosure relates to a lighting system, and more particularly to a lighting system including a power supply device and a plurality of light source units connected to each other via a power line.

Background Art

[0002] Patent Document 1 describes a lighting device including a lighting device and an LED module. The LED module includes a plurality of LEDs connected in series. The lighting device includes a power factor improvement circuit and a buck converter circuit. The power factor improvement circuit is, for example, a boost chopper circuit that boosts an input voltage by a switching operation and applies it to an electrolytic capacitor. The buck converter circuit steps down a DC voltage output from the electrolytic capacitor by a switching operation to generate a predetermined DC current, outputs the DC current, and lights the LEDs of the LED module.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When constructing a system including a plurality of lighting devices described in Patent Document 1, since both the power factor improvement circuit and the buck converter circuit constituting the lighting device are provided in each lighting device, there is a problem that the power loss of the entire system increases.

[0005] An object of the present disclosure is to provide a lighting system capable of reducing the power loss of the entire system.

Means for Solving the Problems

[0006] A lighting system according to one aspect of the present disclosure comprises a power supply unit and a plurality of light source units connected to each other via a power line. The power supply unit has a conversion unit and a control unit. The conversion unit converts an AC voltage supplied from an external power source into a DC voltage. The control unit controls the conversion unit. Each of the plurality of light source units has a light source and a constant current circuit. The DC voltage supplied from the conversion unit via the power line is applied to the light source. The constant current circuit controls the current flowing through the light source. [Effects of the Invention]

[0007] According to one aspect of the present disclosure, a lighting system can be used to reduce the overall power loss of the system. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram of the lighting system according to the embodiment. [Figure 2] Figure 2 is a schematic diagram of the lighting device and light source unit in the same lighting system. [Modes for carrying out the invention]

[0009] (Embodiment) Hereinafter, a lighting system according to the embodiments will be described with reference to the drawings. However, the configuration described in the following embodiments is merely one example of the disclosure. The disclosure is not limited to the following embodiments, and various modifications are possible depending on the design, etc., as long as the effects of the disclosure can be achieved.

[0010] (Embodiment) (1) Overview First, an overview of the lighting system 10 according to this embodiment will be described with reference to Figures 1 and 2.

[0011] As shown in Figure 1, the lighting system 10 according to the embodiment comprises a power supply unit 1 and a plurality of light source units 2. The power supply unit 1 and the plurality of light source units 2 are connected to each other via a power line PL1. The power supply unit 1 has a conversion unit 12 and a control unit 13. The conversion unit 12 converts the AC voltage supplied from the external power supply PS1 into a DC voltage. The control unit 13 controls the conversion unit 12. Each of the plurality of light source units 2 has a light source 21 and a constant current circuit 22. The light source 21 is supplied with a DC voltage from the conversion unit 12 via the power line PL1. The constant current circuit 22 controls the current flowing through the light source 21.

[0012] In the lighting system 10 according to this embodiment, the power supply unit 1 has a conversion unit 12, and each of the multiple light source units 2 has a constant current circuit 22. This makes it possible to reduce the overall power loss of the system compared to the case where each light source unit has both a conversion unit and a constant current circuit.

[0013] (2) Details Next, each component of the lighting system 10 according to the embodiment will be described with reference to Figures 1 and 2.

[0014] As shown in Figures 1 and 2, the lighting system 10 according to this embodiment comprises a power supply unit 1, a plurality of light source units 2, and a dimmer 3. The power supply unit 1 and the plurality of light source units 2 are connected to each other via a power line PL1.

[0015] (2.1) Power supply device As shown in Figure 2, the power supply unit 1 includes a rectifier unit 11, a converter unit 12, a control unit 13, a power supply unit 14, and a dimming unit 15.

[0016] The rectification unit 11 includes, for example, a full-wave rectification circuit in which four diodes are bridge-connected. The rectification unit 11 full-wave rectifies the alternating voltage supplied from the external power supply PS1 and outputs a pulsating direct current voltage. A capacitor that smoothes the pulsating direct current voltage output from the rectification unit 11 and outputs a direct current voltage is connected to the output terminal of the rectification unit 11. Note that the rectification unit 11 may include a half-wave rectification circuit composed of one diode instead of the full-wave rectification circuit.

[0017] The conversion unit 12 converts the alternating voltage supplied from the external power supply PS1 into a direct current voltage. The conversion unit 12 includes, for example, a boost chopper circuit. More specifically, the conversion unit 12 includes a MOSFET and an electrolytic capacitor, and boosts the direct current voltage (input voltage) output from the capacitor connected to the output terminal of the rectification unit 11 by the switching operation of the MOSFET and applies it to the electrolytic capacitor. The external power supply PS1 is, for example, a commercial power supply.

[0018] As shown in FIG. 2, the conversion unit 12 includes a detection unit 121. The detection unit 121 has a resistance element connected in series with the MOSFET and detects the current flowing through the resistance element. The detection unit 121 also has a wireless communication circuit and transmits a wireless signal including the detection result to the dimming unit 15. In the present embodiment, the medium of the wireless signal is radio waves, but it may be, for example, infrared rays or visible light.

[0019] The control unit 13 controls the conversion unit 12. More specifically, the control unit 13 controls the on / off of the MOSFET included in the conversion unit 12. Specifically, the control unit 13 adjusts the frequency and duty ratio of the on / off of the MOSFET so that the voltage across the electrolytic capacitor included in the conversion unit 12 becomes a desired voltage.

[0020] The control unit 13 can be realized by, for example, a computer system having one or more processors and one or more memories. That is, the control unit 13 functions by one or more processors executing a program recorded in one or more memories of the computer system. Here, the program is pre-recorded in the memory of the computer system, but it may be provided through a telecommunication line such as the Internet, or it may be provided by being recorded on a non-temporary recording medium such as a memory card.

[0021] The power supply unit 14 supplies an operating power supply to the control unit 13 and the dimming unit 15. More specifically, the power supply unit 14 supplies a direct current voltage (for example, DC5V) to the control unit 13 and the dimming unit 15 as the operating power supply.

[0022] The dimming unit 15 receives a dimming signal from a dimmer 3 provided outside, and outputs a dimming command for instructing the dimming rate of the light source 21 to the control unit 13 based on the dimming signal. Here, as described above, the detection result of the detection unit 121 provided in the conversion unit 12 of the power supply device 1 is transmitted to the dimming unit 15. The dimming unit 15 calculates (estimates) the number of light source units 2 connected to the power supply device 1 based on the detection result of the detection unit 121. Then, the dimming unit controls the dimming rate of each light source unit 2 so that the power consumption of the plurality of light source units 2 connected to the power supply device 1 does not exceed the power supplyable power of the power supply device 1.

[0023] For example, consider a scenario where five light source units 2 are connected to a power supply unit 1, and the power supply unit 1 is capable of supplying enough power to fully illuminate (100% illumination) all five light source units 2. In this case, if, for example, ten light source units 2 are connected to the power supply unit 1 and all ten light source units 2 are fully illuminated, the power consumption of the ten light source units 2 will exceed the power supply capacity of the power supply unit 1. Therefore, the dimming unit 15 of the power supply unit 1 controls the dimming rate of the light source 21 of each light source unit 2 to 50% or less so that the power consumption of the ten light source units 2 does not exceed the power supply capacity of the power supply unit 1. In other words, in this case, the dimming rate of each light source 21 is capped at 50%. In this way, the dimming unit 15 of the power supply unit 1 controls the dimming rate of each light source 21 so that the power consumption of multiple light sources 21 exceeds the power supply capacity of the power supply unit 1, when the power consumption of multiple light sources 21 exceeds the power supply capacity of the power supply unit 1. As a result, the power consumption of multiple light sources 21 in multiple light source units 2 remains below the power supply capacity of the power supply unit 1.

[0024] Specifically, for example, in the range of 50% or more and 100% or less for the dimming rate due to the dimming signal from the dimmer 3, the dimming unit 15 of the power supply unit 1 controls the dimming rate of each light source 21 to 50% so that the power consumption of the multiple light sources 21 does not exceed the power supply capacity of the power supply unit 1. On the other hand, in the range of less than 50% for the dimming rate due to the dimming signal from the dimmer 3, the dimming unit 15 of the power supply unit 1 controls the dimming rate of each light source 21 to the dimming rate due to the dimming signal, since the power consumption of the multiple light sources 21 does not exceed the power supply capacity of the power supply unit 1.

[0025] Here, the upper limit of the number of light source units 2 that can be connected to the power supply unit 1 is set, for example, based on the dimming lower limit of the light source 21 of each light source unit 2. For example, if the dimming lower limit of the light source 21 is 5%, the number of connectable light source units 2 will be the upper limit when each light source 21 is lit at its dimming lower limit.

[0026] (2.2) Light source unit Each of the multiple light source units 2 has a light source 21 and a constant current circuit 22, as shown in Figure 2.

[0027] The light source 21 is supplied with a DC voltage from the conversion unit 12 of the power supply unit 1 via the power line PL1. The light source 21 includes, for example, a plurality of LEDs (Light-Emitting Diodes) connected in series with each other. Each LED in the light source 21 is lit by a predetermined DC current output from the conversion unit 12 of the power supply unit 1. Note that the light source 21 may also include, for example, organic electro-luminescence (OLED) instead of LEDs.

[0028] The constant current circuit 22 controls the current flowing through the light source 21. The constant current circuit 22 includes, for example, a transistor connected in series with the light source 21, a resistor connected in series with the light source 21 and the transistor, and an operational amplifier. The operational amplifier generates a gate signal corresponding to the difference between the voltage corresponding to the current flowing through the light source 21 and a reference voltage, and outputs it to the transistor. The transistor has a resistance value corresponding to the voltage of the gate signal, thereby controlling the current flowing through the light source 21 to a constant value.

[0029] (3) Power loss of the entire system Next, the power loss of the lighting system 10 according to this embodiment will be explained in comparison with a conventional structure.

[0030] In conventional structures, each light source unit has both a conversion unit and a constant current circuit. On the other hand, in the lighting system 10 according to this embodiment, the power supply unit 1 has a conversion unit 12, and the light source unit 2 has a constant current circuit 22.

[0031] In a conventional structure, let's assume there are 5 light source units and the conversion efficiency of the converter and constant current circuit is 90%. In this case, in order to make the output power of each light source unit 18W, the input power to each light source unit will be 20W (= 18W × 1 / 0.9). Therefore, in this case, 100W of input power is required for the 5 light source units.

[0032] On the other hand, in the lighting system 10 according to the embodiment, the power supply unit 1 has only a conversion unit 12. Therefore, the conversion efficiency of the power supply unit 1 is, for example, 94%. In this case, in order to set the output power from the power supply unit 1 to each light source unit 2 to 18W, the input power to the power supply unit 1 will be 95.7W (= 18W × 5 units × 1 / 0.94). In other words, according to the lighting system 10 according to the embodiment, the difference between input power and output power is smaller compared to the conventional structure, and as a result, power loss can be reduced.

[0033] (4) Effects In the lighting system 10 according to this embodiment, the power supply unit 1 has a conversion unit 12, and each of the multiple light source units 2 has a constant current circuit 22. This makes it possible to reduce the overall power loss of the system compared to the case where each light source unit has both a conversion unit and a constant current circuit.

[0034] Furthermore, in the lighting system 10 according to this embodiment, the power supply unit 1 further includes a dimming unit 15 that receives a dimming signal from the dimmer 3 and outputs a dimming command to the control unit 13 that instructs the dimming rate of the light source 21 based on the dimming signal. This makes it possible to dim the light source 21 in response to the dimming signal from the dimmer 3.

[0035] Furthermore, in the lighting system 10 according to this embodiment, the power consumption of the multiple light sources 21 in the multiple light source units 2 is less than or equal to the power supply capacity of the power supply device 1. This makes it possible to light up the multiple light sources 21 within a range that does not exceed the power supply capacity of the power supply device 1. In particular, as in this embodiment, when the power supply device 1 has a dimming unit 15, it is possible to dim the multiple light sources 21 within a range that does not exceed the power supply capacity of the power supply device 1.

[0036] (5) Variant The embodiments described above are merely one of many embodiments of this disclosure. The embodiments described above can be modified in various ways depending on the design, etc., as long as the objectives of this disclosure are achieved. The following lists some modifications of the embodiments described above. The modifications described below can be combined and applied as appropriate.

[0037] The lighting system 10 in this disclosure includes a computer system. The computer system mainly consists of a processor and memory as hardware. The functionality of the lighting system 10 in this disclosure is realized by the processor executing a program recorded in the memory of the computer system. The program may be pre-recorded in the memory of the computer system, provided via a telecommunications line, or provided on a non-temporary recording medium such as a memory card, optical disk, or hard disk drive that can be read by the computer system. The processor of the computer system consists of one or more electronic circuits including semiconductor integrated circuits (ICs) or large-scale integrated circuits (LSIs). The integrated circuits such as ICs and LSIs referred to here are named differently depending on the degree of integration, and include integrated circuits called system LSIs, VLSIs (Very Large Scale Integration), or ULSIs (Ultra Large Scale Integration). Furthermore, FPGAs (Field-Programmable Gate Arrays) that are programmed after the manufacture of the LSI, or logic devices that allow for the reconfiguration of junction relationships or circuit compartments within the LSI, can also be used as processors. Multiple electronic circuits may be integrated onto a single chip or distributed across multiple chips. Multiple chips may be integrated onto a single device or distributed across multiple devices. The computer system referred to here includes a microcontroller having one or more processors and one or more memories. Therefore, the microcontroller also consists of one or more electronic circuits, including semiconductor integrated circuits or large-scale integrated circuits.

[0038] Furthermore, it is not essential for the lighting system 10 to have multiple functions integrated into a single housing; the components of the lighting system 10 may be distributed across multiple housings. In addition, at least some of the functions of the lighting system 10, for example, the functions of the control unit 13 of the power supply unit 1, may be realized by the cloud (cloud computing) or the like.

[0039] In the above embodiment, the detection result of the detection unit 121 of the conversion unit 12 is transmitted to the dimming unit 15 by a wireless signal. Alternatively, for example, the detection unit 121 of the conversion unit 12 and the dimming unit 15 may be connected by a communication line, and the detection result of the detection unit 121 may be transmitted to the dimming unit 15 via the communication line.

[0040] In the above embodiment, the conversion unit 12 includes a boost chopper circuit, but the conversion unit 12 may include a buck-boost chopper circuit or a buck chopper circuit instead of a boost chopper circuit.

[0041] In the embodiment described above, the constant current circuit 22 includes a transistor, a resistor, and an operational amplifier, but it may also include, for example, a shunt regulator, in which case it is also possible to control the current flowing to the light source 21 to a constant value.

[0042] (Appearance) This specification discloses the following aspects:

[0043] The lighting system (10) according to the first embodiment comprises a power supply unit (1) and a plurality of light source units (2) connected to each other via a power line (PL1). The power supply unit (1) has a conversion unit (12) and a control unit (13). The conversion unit (12) converts an AC voltage supplied from an external power supply (PS1) into a DC voltage. The control unit (13) controls the conversion unit (12). Each of the plurality of light source units (2) has a light source (21) and a constant current circuit (22). The light source (21) has a DC voltage supplied from the conversion unit (12) via the power line (PL1) applied to it. The constant current circuit (22) controls the current flowing through the light source (21).

[0044] This embodiment makes it possible to reduce the overall power loss of the system.

[0045] In the lighting system (10) according to the second embodiment, the power supply unit (1) further includes a dimming unit (15). The dimming unit (15) receives a dimming signal from an externally provided dimmer (3) and outputs a dimming command to the control unit (13) that specifies the dimming rate of the light source (21) based on the dimming signal.

[0046] According to this embodiment, it is possible to dim the light source (21) in response to a dimming signal from the dimmer (3).

[0047] In the lighting system (10) according to the third embodiment, in the second embodiment, the dimming unit (15) of the power supply device (1) controls the dimming rate so that the power consumption of the multiple light sources (21) exceeds the power supply capacity of the power supply device (1) and the power consumption of the multiple light sources (21) is less than or equal to the power supply capacity.

[0048] According to this embodiment, it is possible to dim and light up multiple light sources (21) within a range that does not exceed the power supply capacity of the power supply device (1).

[0049] In the lighting system (10) according to the fourth embodiment, in any one of the first to third embodiments, the power consumption of the multiple light sources (21) in the multiple light source units (2) is less than or equal to the power supplyable by the power supply device (1).

[0050] According to this embodiment, it is possible to light up multiple light sources (21) within a range that does not exceed the power supply capacity of the power supply device (1).

[0051] The configurations relating to the second to fourth aspects are not essential to the lighting system (10) and can be omitted as appropriate. [Explanation of Symbols]

[0052] 1 Power supply 2 Light source units 3 dimmer 10 Lighting Systems 12 Conversion section 13 Control Unit 15 Dimming section 21 Light source 22 Constant current circuit PL1 power line PS1 external power supply

Claims

1. It comprises power supply units and multiple light source units connected to each other via power lines, The aforementioned power supply device is A conversion unit that converts AC voltage supplied from an external power source into DC voltage, It includes a control unit that controls the conversion unit, Each of the aforementioned plurality of light source units is A light source to which the DC voltage supplied from the conversion unit via the power line is applied, The system includes a constant current circuit that controls the current flowing through the light source, Lighting system.

2. The aforementioned power supply device is The system further includes a dimming unit that receives a dimming signal from an externally installed dimmer and outputs a dimming command to the control unit that instructs the dimming rate of the multiple light sources in the multiple light source units based on the dimming signal. The lighting system according to claim 1.

3. The dimming unit of the power supply device controls the dimming rate so that the power consumption of the plurality of light sources is less than or equal to the supplyable power when the power consumption of the plurality of light sources exceeds the supplyable power of the power supply device. The lighting system according to claim 2.

4. The power consumption of the multiple light sources in the multiple light source units is less than or equal to the power supply capacity of the power supply device. A lighting system according to any one of claims 1 to 3.

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