JP5058778B2 - Light source lighting device, lighting fixture, lighting system - Google Patents

Description

  The present invention relates to a light source lighting device, a lighting fixture, and a lighting system that are connected to a DC power source via a pair of DC supply lines and that turn on a light source by receiving power supply from the DC power source.

  2. Description of the Related Art Conventionally, in a lighting device to which DC power is supplied or a lighting system including a plurality of lighting devices, a DC power source (for example, an automobile battery) is connected via a pair of DC supply lines. Various light source lighting devices configured to light a light source such as (LED) are used.

This type of light source lighting device is generally a lighting means for lighting a light source so that the light output of the light source is maintained at a specified value even if a voltage Vin (hereinafter referred to as input voltage) Vin input from a DC supply line fluctuates. (When the light source is a light emitting diode, a constant current circuit for supplying a constant current to the light source) is provided (see, for example, Patent Document 1). Therefore, the input power Vin = Vin × Iin (the circuit efficiency is constant) represented by the product of the input voltage Vin and a current (hereinafter referred to as input current) Iin input from the DC supply line is equal to the input voltage Vin. It remains constant regardless of fluctuations.
JP 2006-210836 A (page 3)

  By the way, when this type of light source lighting device is used, for example, the current flowing through the other DC load supply line connected to the same DC supply line as the light source lighting device increases the current flowing through the DC supply line, or the DC supply. A voltage drop generated between the DC power source and the light source lighting device may be increased due to the large impedance of the DC supply line determined according to the length and diameter of the line. When the voltage drop between the DC power source and the light source lighting device increases in this way, the input voltage Vin input from the DC supply line to the light source lighting device decreases even if the output voltage of the DC power source is constant.

  Here, as described above, since the light source lighting device includes lighting means (for example, a constant current circuit) that maintains the light output of the light source at a specified value, the input power Win is kept constant, and the DC supply line When the input voltage Vin from the input voltage decreases, the input current Iin increases due to the relationship of Iin = Win / Vin. At this time, the voltage drop caused by the impedance Z of the DC supply line increases as the current flowing in the DC supply line increases, and even if the output voltage Vo of the DC power supply is constant, Vin = Vo−Iin × Z. The input voltage Vin further decreases, and as a result, for example, the light source cannot be turned on, or all loads connected to the same DC supply line as the light source lighting device do not operate normally due to a decrease in the input voltage. May occur.

  The present invention has been made in view of the above circumstances, and is a light source lighting device and a lighting fixture that can turn on a light source while preventing a further decrease in the input voltage when the input voltage from the DC supply line decreases. An object is to provide a lighting system.

The invention of claim 1, supplied with electric power from this direct current power supply is connected to the DC power source via a pair of DC supply line, the magnitude of the current flowing through the self is reflected in the size of the light output A light source lighting device for lighting a light source, a step-down chopper circuit for controlling a current flowing through the light source, a detection means for detecting a voltage input from a DC supply line to the step-down chopper circuit as an input voltage, and an input voltage being a first The step-down chopper so that the current flowing through the light source is maintained at a predetermined value regardless of the fluctuation of the input voltage when the voltage is equal to or higher than the predetermined voltage, and the current flowing through the light source becomes smaller than the predetermined value when the input voltage falls below the first voltage. And a control means for controlling the circuit .

According to this configuration, the control means, the input voltage the current flowing through the light source regardless of variations in the input voltage when the above first voltage is maintained at a predetermined value, the input voltage is below the first voltage Since the step-down chopper circuit is controlled so that the current flowing through the light source becomes smaller than the predetermined value , when the input voltage is equal to or higher than the first voltage, the light output of the light source is maintained at the specified value regardless of the fluctuation of the input voltage. When the input voltage falls below the first voltage due to a decrease in the input voltage, the light output of the light source is made lower than the specified value, thereby suppressing an increase in the input current from the DC supply line due to the decrease in the input voltage. Can do. In short, it is possible to suppress an increase in the current flowing through the DC supply line as the input voltage from the DC supply line decreases, and thus it is possible to prevent an increase in voltage drop that occurs between the DC power supply and the light source lighting device. . That is, when the input voltage from the DC supply line to the light source lighting device decreases, the input voltage can be prevented from further decreasing. As a result, for example, the light source cannot be turned on or the same DC as the light source lighting device. It is possible to avoid problems such as that other loads connected to the supply line do not operate normally due to a decrease in input voltage.

In addition, according to this configuration, the control unit lowers the current flowing through the light source to lower the light output of the light source below a specified value. You can have use a light source to reflect the size of the light output.

According to a second aspect of the present invention, in the first aspect of the invention, the control means determines a reduction amount from the predetermined value of the current flowing through the light source in accordance with a reduction amount from the first voltage in the input voltage. It is characterized by doing.

According to this configuration, even if the input voltage from the DC supply line is greatly reduced, the increase in the input current from the DC supply line is ensured by increasing the amount of decrease from the predetermined value of the current flowing through the light source. Can be suppressed. Therefore, when the input voltage from the DC supply line to the light source lighting device decreases, it is possible to reliably prevent further decrease in the input voltage.

According to a third aspect of the present invention, in the first or second aspect of the invention, the control means turns off the light source when the input voltage falls below a second voltage lower than the first voltage. Features.

  According to this configuration, when the input voltage from the DC supply line to the light source lighting device is abnormally lowered and falls below the second voltage, the light source and the circuit can be protected by stopping the power supply to the light source. .

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the control unit turns off the light source when the input voltage exceeds a third voltage higher than the first voltage. It is characterized by making it.

  According to this configuration, when the input voltage from the DC supply line to the light source lighting device rises abnormally and exceeds the third voltage, the light source and the circuit can be protected by stopping the power supply to the light source. .

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the output voltage of the DC power source is 50 V or less.

  According to this configuration, in a relatively narrow range where the input voltage from the DC supply line is 50 V or less, compared to the case where the input voltage exceeds 50 V, the influence of the decrease in the input voltage is greater, and the load may not operate normally. Therefore, when the input voltage from the DC supply line to the light source lighting device decreases, it is particularly useful to prevent further decrease in the input voltage.

The invention according to claim 6 is characterized in that the fixture body is provided with the light source lighting device according to any one of claims 1 to 5 .

  According to this configuration, it is possible to suppress an increase in the current flowing through the DC supply line as the input voltage from the DC supply line decreases, and accordingly, a voltage drop generated between the DC power supply and the light source lighting device increases. Can be prevented. That is, when the input voltage from the DC supply line to the light source lighting device decreases, the input voltage can be prevented from further decreasing.

A seventh aspect of the invention is characterized in that a plurality of lighting fixtures according to the sixth aspect are provided.

  According to this configuration, it is possible to suppress an increase in the current flowing through the DC supply line as the input voltage from the DC supply line decreases, and accordingly, a voltage drop generated between the DC power supply and the light source lighting device increases. Can be prevented. That is, when the input voltage from the DC supply line to the light source lighting device decreases, the input voltage can be prevented from further decreasing.

  The present invention has an effect that when the input voltage from the DC supply line to the light source lighting device decreases, the light source can be lit by preventing further decrease in the input voltage.

  As shown in FIG. 2, the light source lighting device described in each of the following embodiments uses an AC power source AC such as a commercial power source as a DC power source by an AC / DC converter 112 disposed in a distribution board 110 such as a house. It is used in a DC distribution system that converts and distributes DC power from the distribution board 110 to a DC outlet such as a DC outlet 131 that is installed in each room and has a pair of positive and negative power feeding units.

  Here, the DC power distribution system will be briefly described below with reference to FIG.

  In the following description, a description will be given assuming a detached house as a building to which the DC power distribution system is applied, but this does not preclude the application of the technical concept of the DC power distribution system to an apartment house. As shown in FIG. 2, the house H is provided with a DC power supply unit 101 that outputs DC power and a DC device 102 as a load driven by the DC power, and an output end of the DC power supply unit 101. DC power is supplied to the DC device 102 through the DC supply line Wdc connected to the. A current flowing through the DC supply line Wdc is monitored between the DC power supply unit 101 and the DC device 102. When an abnormality is detected, power is supplied from the DC power supply unit 101 to the DC device 102 on the DC power supply line Wdc. A DC breaker 114 is provided for limiting or blocking the current.

  The DC supply line Wdc is used as both a DC power supply path and a communication path, and is connected to the DC supply line Wdc by superimposing a communication signal for transmitting data on a DC voltage using a high-frequency carrier wave. Enables communication between devices. This technique is similar to a power line carrier technique in which a communication signal is superimposed on an AC voltage in a power line that supplies AC power.

  The DC supply line Wdc is connected to the home server 116 via the DC power supply unit 101. The in-home server 116 is a main device for constructing a home communication network (hereinafter referred to as “home network”), and communicates with a subsystem constructed by the DC device 102 in the home network.

  In the example shown in the drawing, as an subsystem, an illumination system comprising an information equipment system K101 comprising an information-system DC device 102 such as a personal computer, a wireless access point, a router, and an IP telephone, and an illumination system DC equipment 102 such as a lighting fixture. K102 and K105, an intercom system K103 including a DC device 102 that handles visitor correspondence and intruder monitoring, and a residential alarm system K104 including a warning DC device 102 such as a fire detector. Each subsystem constitutes a self-supporting distributed system, and can operate even with the subsystem alone.

  The above-described DC breaker 114 is provided in association with a subsystem. In the illustrated example, four DCs are associated with the information equipment system K101, the lighting system K102 and the intercom system K103, the house alarm system K104, and the lighting system K105. A breaker 114 is provided. When a plurality of subsystems are associated with one DC breaker 114, a connection box 121 for dividing the system of the DC supply line Wdc is provided for each subsystem. In the illustrated example, a connection box 121 is provided between the illumination system K102 and the intercom system K103.

  As the information equipment system K101, there is provided an information equipment system K101 composed of a DC equipment 102 connected to a DC outlet 131 arranged in advance in the house H (constructed when the house H is constructed) in the form of a wall outlet or a floor outlet.

  The lighting systems K102 and K105 include a lighting system K102 composed of a lighting device (DC device 102) arranged in advance in the house H and a lighting device (DC device 102) connected to a hook ceiling 132 arranged in advance on the ceiling. An illumination system K105 is provided. At the time of interior construction of the house H, the contractor attaches the lighting fixture to the hook ceiling 132, or the householder himself attaches the lighting fixture.

  In addition to using an infrared remote control device, a control instruction for the lighting apparatus that is the DC device 102 constituting the lighting system K102 can be given using a communication signal from the switch 141 connected to the DC supply line Wdc. That is, the switch 141 has a communication function together with the DC device 102. In addition, a control instruction may be given by a communication signal from another DC device 102 in the home network or the home server 116 regardless of the operation of the switch 141. The instructions to the lighting fixture include lighting, extinguishing, dimming, and blinking lighting.

  Since any DC device 102 can be connected to the DC outlet 131 and the hooking ceiling 132 described above and DC power is output to the connected DC device 102, the DC outlet 131 and the hooking ceiling 132 are distinguished below. When it is not necessary, it is called “DC outlet”.

  These DC outlets are provided with plug-in connection ports (power feeding portions) into which contacts (not shown) provided directly on the DC device 102 or contacts (not shown) provided via connecting wires are inserted. It has a structure in which a contact receiver that opens to the body and directly contacts the contact inserted into the connection port is held by the container. That is, the direct current outlet supplies power in a contact manner. When the DC device 102 connected to the DC outlet has a communication function, a communication signal can be transmitted through the DC supply line Wdc. A communication function is provided not only in the DC device 102 but also in the DC outlet.

  The home server 116 not only is connected to the home network, but also has a connection port connected to the wide area network NT that constructs the Internet. When the in-home server 116 is connected to the wide area network NT, it is possible to receive services from the center server 200 that is a computer server connected to the wide area network NT.

  The service provided by the center server 200 includes a service that enables monitoring and control of equipment (including mainly the DC equipment 102 but also other equipment having a communication function) connected to the home network through the wide area network NT. is there. This service makes it possible to monitor and control devices connected to the home network using a communication terminal (not shown) having a browser function such as a personal computer, Internet TV, or mobile phone.

  The in-home server 116 has both functions of communication with the center server 200 connected to the wide area network NT and communication with equipment connected to the home network, and identification information about equipment in the home network ( Here, it is assumed that an IP address is used).

  The home server 116 enables monitoring and control of home devices through the center server 200 from a communication terminal connected to the wide area network NT by using a communication function with the center server 200. The center server 200 mediates between home devices and communication terminals on the wide area network NT.

  When monitoring and controlling home devices from a communication terminal, monitoring and control requests are stored in the center server 200, and the home device periodically performs one-way polling communication to monitor from the communication terminal. And receive control requests. With this operation, it is possible to monitor and control devices in the house from the communication terminal.

  Further, when an event that should be notified to the communication terminal, such as a fire detection, occurs in the home device, the home device notifies the center server 200, and the center server 200 notifies the communication terminal by e-mail.

  An important function among the communication functions with the home network in the home server 116 is the detection and management of the devices constituting the home network. The home server 116 automatically detects devices connected to the home network by applying UPnP (Universal Plug and Play). The home server 116 includes a display device 117 having a browser function, and displays a list of detected devices on the display device 117. The display device 117 has a configuration with a touch panel type or an operation unit, and can perform an operation of selecting desired contents from options displayed on the screen of the display device 117. Therefore, the user (contractor or householder) of the home server 116 can monitor or control the device on the screen of the display device 117. The display device 117 may be provided separately from the home server 116.

  The in-home server 116 manages information related to device connection, and grasps the type, function, and address of the device connected to the home network. Accordingly, the devices in the home network can be operated in conjunction with each other. Information on the connection of the device is automatically detected as described above. In order to operate the device in an interlocking manner, the device itself is automatically associated with the attribute held by the device itself, and the home server 116 is configured as a personal computer. It is also possible to connect various information terminals and use the browser function of the information terminals to associate devices.

  Each device holds the relationship of the interlocking operation of the devices. Therefore, the device can operate in an interlocked manner without passing through the home server 116. By associating the linked operations for each device, for example, by operating a switch that is a device, it is possible to turn on or off the lighting fixture that is the device. In many cases, the association of the interlocking operations is performed within the subsystem, but the association beyond the subsystem is also possible.

  By the way, the DC power supply unit 101 basically generates DC power by power conversion of an AC power supply AC supplied from outside the house like a commercial power supply. In the configuration shown in the figure, the AC power source AC is input to an AC / DC converter 112 including a switching power source through a main circuit breaker 111 attached to the distribution board 110 as an internal unit. The DC power output from the AC / DC converter 112 is connected to each DC breaker 114 through the cooperative control unit 113.

  The DC power supply unit 101 is provided with a secondary battery 162 in preparation for a period in which power is not supplied from the AC power supply AC (for example, a power failure period of the commercial power supply AC). It is also possible to use a solar cell 161 or a fuel cell 163 that generates DC power. The solar battery 161, the secondary battery 162, and the fuel battery 163 are distributed power supplies with respect to the main power supply including the AC / DC converter 112 that generates DC power from the AC power supply AC. In the illustrated example, the solar cell 161, the secondary battery 162, and the fuel cell 163 include a circuit unit that controls the output voltage, and the secondary battery 162 includes a circuit unit that controls charging as well as discharging.

  Of the distributed power sources, the solar cell 161 and the fuel cell 163 are not necessarily provided, but the secondary battery 162 is preferably provided. The secondary battery 162 is charged in a timely manner by a main power source or other distributed power source, and the secondary battery 162 is discharged not only in a period in which power is not supplied from the AC power source AC but also in a timely manner as necessary. The coordination control unit 113 performs charge / discharge of the secondary battery 162 and coordination between the main power source and the distributed power source. That is, the cooperative control unit 113 functions as a DC power control unit that controls the distribution of power from the main power source and the distributed power source constituting the DC power supply unit 101 to the DC device 102. Note that a configuration may be adopted in which the outputs of the solar cell 161, the secondary battery 162, and the fuel cell 163 are converted into AC power and used as input power of the AC / DC converter 112.

  Since the driving voltage of the DC device 102 is selected from a plurality of types of voltages depending on the device, a DC / DC converter is provided in the cooperative control unit 113 to convert the DC voltage obtained from the main power source and the distributed power source into a necessary voltage. Is desirable. Normally, one type of voltage is supplied to one subsystem (or DC device 102 connected to one DC breaker 114), but three or more wires are used for one subsystem. A plurality of types of voltages may be supplied. Alternatively, it is possible to adopt a configuration in which the DC supply line Wdc is of a two-wire type and the voltage applied between the lines is changed with time. The DC / DC converter may be provided in a plurality of dispersed manners like the DC breaker.

  In the above configuration example, only one AC / DC converter 112 is illustrated, but a plurality of AC / DC converters 112 can be arranged in parallel, and when a plurality of AC / DC converters 112 are provided. It is desirable to increase or decrease the number of AC / DC converters 112 that are operated according to the magnitude of the load.

  The AC / DC converter 112, the cooperative control unit 113, the DC breaker 114, the solar cell 161, the secondary battery 162, and the fuel cell 163 described above are provided with a communication function, and include a main power source, a distributed power source, and a DC device 102. It is possible to perform cooperative operations that deal with the load status. The communication signal used for this communication is transmitted in the form of being superimposed on the DC voltage in the same manner as the communication signal used for the DC device 2.

  In the above example, the AC / DC converter 112 is arranged in the distribution board 110 in order to convert the AC power output from the main breaker 111 into DC power by the AC / DC converter 112. On the output side, a branch breaker (not shown) provided in the distribution board 110 branches the AC supply line into a plurality of systems, and an AC / DC converter is provided on the AC supply line of each system to convert it into DC power for each system. You may employ | adopt the structure to do.

  In this case, since the DC power supply unit 101 can be provided for each floor or room of the house H, the DC power supply unit 101 can be managed for each system, and the DC device 102 that uses DC power and Since the distance of the DC supply line Wdc between the two is reduced, the power loss due to the voltage drop in the DC supply line Wdc can be reduced. Also, the main breaker 111 and the branch breaker are housed in the distribution board 110, and the AC / DC converter 112, the cooperative control unit 113, the DC breaker 114, and the home server 116 are housed in a separate board from the distribution board 110. Also good.

  Below, the example which applied this invention to the light source lighting device with which the lighting fixture (DC apparatus 102) which comprises the lighting system K102 in the DC distribution system mentioned above is demonstrated is demonstrated, but this invention is other than this kind of lighting fixture. The present invention can also be applied to a light source lighting device provided in the apparatus. Here, the magnitude of the DC voltage applied to the DC device 102 from the DC outlet is set to be lower (for example, 24V, 50V, etc.) than the AC commercial power supply.

(Embodiment 1)
The light source lighting device 1 of the present embodiment is connected to a DC power source E (DC power supply unit 101) via a pair of DC supply lines Wdc as shown in FIG. To light the light source 2. Here, a light emitting diode (LED) that reflects the magnitude of the current Ila flowing through the light source 2 in the magnitude of the light output is employed as the light source 2.

  A specific configuration of the light source lighting device 1 will be described with reference to FIG. The light source lighting device 1 includes a current control circuit 3 that controls a current flowing through the light source 2 between a pair of DC input terminals T1 and T2 connected to a DC power source E via a DC supply line Wdc, and a DC supply line Wdc. A detection unit (detection means) 4 that detects a voltage applied between the DC input terminals T1 and T2 as an input voltage Vin is provided.

  The current control circuit 3 is configured so that the cathode is connected to the series circuit of the switching element Q1, the inductor L1, and the capacitor C1 connected between the DC input terminals T1 and T2, and the connection point side of the switching element Q1 and the inductor L1. A step-down chopper circuit including a diode D1 connected between both ends of a series circuit of an inductor L1 and a capacitor C1, and a drive circuit 5 for turning on and off the switching element Q1 according to a drive signal from a control unit (control means) 6 described later. Have. Furthermore, one end of the capacitor C1 is connected to one of a pair of output ends T3 and T4 connected to the light source 2, and the other end of the capacitor C1 is connected to the other end of the output ends T3 and T4 via a resistor R3. The As a result, a current corresponding to the voltage generated at both ends of the capacitor C1 flows through the series circuit of the light source 2 and the resistor R3. In addition, an output voltage detection unit formed by connecting a pair of resistors R4 and R5 in series is provided between both ends of the capacitor C1. A MOSFET is used as the switching element Q1.

  Here, the magnitude of the voltage generated across the capacitor C <b> 1 is controlled by the switching element Q <b> 1 being on / off controlled by the drive signal output from the control unit 6 to the drive circuit 5. The controller 6 monitors the magnitude of the lamp voltage Vla generated across the capacitor C1 based on the voltage across the resistor R5, and further monitors the lamp current Ila flowing through the light source 2 based on the voltage across the resistor R3. The lamp voltage Vla is used to detect an abnormal operation or the like of the current control circuit 3, and the control unit 6 turns off the switching element Q1 and stops the output of the current control circuit 3 when the current control circuit 3 operates abnormally.

  The detection unit 4 includes a series circuit of resistors R1 and R2 connected between a pair of DC input terminals T1 and T2. The control unit 6 determines a DC supply line based on the voltage across the resistor R2 constituting the detection unit 4. The input voltage Vin input to the light source lighting device 1 from Wdc is monitored.

Incidentally, the light source lighting device 1 of the present embodiment, the control unit 6, as shown in FIG. 1 (b), variation in the input voltage Vin when the first voltage V ₁ or the input voltage Vin is a predetermined maintaining the specified value phi ₀ light output of the light source 2 regardless of the input voltage Vin falls below the voltage V ₁ of the first light source 2 a light output to less than the specified value phi _0, the drive signal To turn on / off the switching element Q1. Here, the lower limit value of the input voltage Vin in the range in which the light source lighting device 1 can operate normally is the second voltage V ₂ , the upper limit value is the third voltage V _3, and the first voltage V ₁ is the second voltage V ₁ . Is set to a value larger than the voltage V _{2 and} smaller than the third voltage (V ₂ <V ₁ <V ₃ ). Here, the third voltage _{V 3} and 50V or less.

That is, in the present embodiment, the input voltage Vin is lower than the first voltage V ₁ when the input voltage Vin is equal to or higher than the _first voltage V ₁ within the normal operation range (the range of V _{2 to} V ₃ ) of the light source lighting device 1. The output control of the current control circuit 3 by the control unit 6 differs depending on the case.

Specifically, when the 4 to the input voltage Vin detected by the detecting section 4 as indicated and the third voltage _{V 3} or less at the voltage _{V 1} or more _{(V 1 ≦ Vin ≦ V 3} ) The control unit 6 performs on / off control of the switching element Q1 of the current control circuit 3 so that the lamp current Ila flowing through the light source 2 becomes a constant current maintained at a predetermined value (for example, a rated lamp current). Here, since the light source 2 is a light emitting diode that reflects the magnitude of the current flowing through the light source 2 in the magnitude of the light output, the light output of the light source 2 is constant by controlling the light source 2 to flow a constant current ( The specified value φ ₀ ) is maintained. On the other hand, when the input voltage Vin detected by the detection unit 4 is less than the first voltage V ₁ and is equal to or higher than the second voltage V ₂ (V ₂ ≦ Vin <V ₁ ), the control unit 6 flows to the light source 2. The switching element Q1 of the current control circuit 3 is on / off controlled so that the lamp current Ila is smaller than the predetermined value. By reducing the current flowing in this way to the light source 2, the light output of the light source 2 becomes lower than the prescribed value phi _0.

  Here, a method of reducing the magnitude (absolute value) of the lamp current Ila by PWM control that changes the on-duty of the switching element Q1 is adopted to reduce the lamp current Ila flowing through the light source 2. The lamp current Ila may be decreased by periodically outputting the current Ila and adjusting the length of time for which the lamp current Ila is allowed to flow per unit time.

According to the configuration described above, when the input voltage Vin input from the pair of DC supply lines Wdc to the light source lighting device 1 is equal to or higher than the _first voltage V1, a constant current is supplied to the light source 2 regardless of fluctuations in the input voltage Vin. it is possible to maintain the size of the light output of the light source 2 to the specified value phi ₀ by flowing. On the other hand, for example, when a current flows through another load (DC device 102) connected to the same DC supply line Wdc as that of the light source lighting device 1, the current flowing through the DC supply line Wdc increases, or the DC supply line Wdc. A voltage drop occurs between the DC power source E and the light source lighting device 1 due to the large impedance Z of the DC supply line Wdc determined according to the length, the wire diameter, etc., and the input voltage Vin decreases. below 1 of voltage V _1, and lower than the prescribed value phi ₀ light output of the light source 2 by reducing the lamp current Ila to flow to the light source 2, thereby, the DC supply line Wdc with decreasing input voltage Vin From the input current Iin can be suppressed.

  That is, when the input voltage Vin to the light source lighting device 1 decreases, the input power Win (= Vin ×) of the light source lighting device 1 is reduced by reducing the output of the light source lighting device 1 (here, the lamp current Ila flowing through the light source 2). Iin) can be reduced, so that it is possible to prevent the input current Iin from increasing as the input voltage Vin decreases as in the case where the input power Win is kept constant. As a result, it is possible to suppress an increase in the current flowing through the DC supply line Wdc with a decrease in the input voltage Vin, and it is possible to prevent a voltage drop that occurs between the DC power source E and the light source lighting device 1 from increasing. When the input voltage Vin to the light source lighting device 1 decreases, the input voltage Vin can be prevented from further decreasing. Therefore, for example, the light source 2 cannot be turned on, or another load connected to the same DC supply line Wdc as the light source lighting device 1 does not operate normally due to a decrease in the voltage input from the DC supply line Wdc. It is possible to avoid problems such as.

Since the light output of the light source 2 is reduced when the input voltage Vin is lower than the _first voltage V1, it is indicated that the user is in an abnormal state (the input voltage Vin is reduced). There is also an advantage that it is possible to make a notification by lowering.

Incidentally, in the present embodiment, as shown in FIG. 1 (b) and FIG. 4, the control unit 6, when the input voltage Vin is within the range from the voltage V ₁ to a second voltage V _2, the input depending on the amount of reduction from the first voltages V ₁ of the voltage Vin, the decrease from the specified value phi ₀ in the light output of the light source 2 (i.e., the amount of decrease from the predetermined value of the lamp current Ila to flow to the light source 2 ). Here, the amount of decrease in the input voltage Vin and the amount of decrease in the light output of the light source 2 (that is, the amount of decrease in the lamp current Iin) are proportional to each other. However, the present invention is not limited to this example. The amount of decrease in the light output of the light source 2 only needs to increase as it increases.

According to this configuration, since the amount of decrease in the output of the light source lighting device 1 is determined according to the amount of decrease in the input voltage Vin of the light source lighting device 1 from the _first voltage V 1, the input voltage of the light source lighting device 1 is determined. Even if Vin decreases significantly, in that case, the output of the light source lighting device 1 is significantly decreased, so that the increase of the input current Iin from the DC supply line Wdc to the light source lighting device 1 is reliably suppressed. It becomes possible to do. Therefore, when the input voltage Vin of the light source lighting device 1 decreases, the input voltage Vin can be reliably prevented from further decreasing.

Further, in the present embodiment, when the input voltage Vin of the light source lighting device 1 is abnormally lowered and falls below the second voltage V ₂ , the control unit 6 stops the power supply from the current control circuit 3 to the light source 2. Then, the light source 2 is operated to be turned off. Further, even when the input voltage Vin of the light source lighting device 1 rises abnormally and exceeds the _third voltage V ₃ , the control unit 6 stops the power supply from the current control circuit 3 to the light source 2 and turns on the light source. 2 is turned off. Thereby, when the input voltage Vin deviates from the normal operating range (the range of V _{2 to} V ₃ ) of the light source lighting device 1, the power supply from the light source lighting device 1 to the light source 2 is stopped. Each circuit component of the lighting device 1 can be protected.

  In the above embodiment, a light emitting diode is used as the light source 2. However, the light source 2 is not limited to the light emitting diode, and the light source 2 that reflects the magnitude of the current flowing through the light source is used. In such a case, a circuit similar to the above embodiment can be employed.

(Embodiment 2)
The light source lighting device 1 of the present embodiment employs, as the light source 2, a high-intensity discharge lamp (HID lamp) that reflects the magnitude of power supplied to itself in the magnitude of light output. This is different from the light source lighting device 1 of FIG.

  A specific configuration of the light source lighting device 1 of the present embodiment will be described with reference to FIG. The light source lighting device 1 includes a detection unit 4 and a power control circuit 7 that controls the amount of power supplied to the light source 2 between the DC input terminals T1 and T2, and further outputs the power control circuit 7. A power conversion circuit 8 that converts DC power into AC power and a resonance circuit 9 that is inserted between the power conversion circuit 8 and the pair of output terminals T3 and T4 are provided.

  The power control circuit 7 is a step-down chopper circuit similar to the current control circuit 3 of the first embodiment, and one end of the capacitor C1 is connected to one input end of the power conversion circuit 8, and the other end of the capacitor C1 is connected to the resistor R3. To the other input terminal of the power conversion circuit 8.

  The power conversion circuit 8 is configured by a full bridge circuit of switching elements Q2 to Q5 connected between both ends of the capacitor C1 of the power control circuit 7. That is, between the both ends of the capacitor C1, the series circuit of the switching elements Q2 and Q4 and the series circuit of the switching elements Q3 and Q5 are connected in parallel, and the switching elements Q2 and Q5 are turned on and the switching elements Q3 and Q4 are turned on. Are alternately switched between a period in which switching elements Q3 and Q4 are on and a period in which switching elements Q2 and Q5 are off, thereby connecting the connection point between switching elements Q2 and Q4 and the connection point between switching elements Q3 and Q5. AC power is generated between them. Here, each of the switching elements Q2 to Q5 is composed of a MOSFET, and is on / off controlled by the control unit 6.

  A connection point between the switching element Q2 and the switching element Q4 is connected to one output terminal T3 via the inductor L2, and a connection point between the switching element Q3 and the switching element Q5 is connected to the other output terminal T4. The resonance circuit 9 includes the inductor L2 and a capacitor C2 inserted between the output terminals T3 and T4.

  The controller 6 monitors the magnitude of the lamp voltage Vla generated across the capacitor C1 based on the voltage across the resistor R5, and further monitors the lamp current Ila flowing through the light source 2 based on the voltage across the resistor R3. Here, if the power supplied to the light source 2 is the lamp power Wla, the lamp power Wla is represented by the product of the lamp voltage Vla and the lamp current Ila (Wla = Vla × Ila). The lamp voltage Vla is used for detecting abnormal operation of the power control circuit 7, lamp out, and the like. The control unit 6 turns off the switching element Q1 when the power control circuit 7 operates abnormally or when the lamp is out of power. 7 output is stopped.

By the way, in the light source lighting device 1 of this embodiment, as shown in FIG. 6, the input voltage Vin detected by the detection unit 4 is not less than the first voltage V _{1 and not} more than the third voltage V ₃ (V ₁ ≦ Vin ≦ V ₃ ), the control unit 6 switches the switching element Q1 of the power control circuit 7 so that the lamp power Wla supplied to the light source 2 becomes a constant power maintained at a predetermined value (for example, rated lamp power). ON / OFF control. Here, since the light source 2 is a high-intensity discharge lamp that reflects the magnitude of power supplied to itself in the magnitude of light output, the light source 2 can be controlled by supplying constant power to the light source 2. Is maintained constant (specified value φ ₀ ). On the other hand, when the input voltage Vin detected by the detection unit 4 is less than the first voltage V ₁ and is equal to or higher than the second voltage V ₂ (V ₂ ≦ Vin <V ₁ ), the control unit 6 supplies the light source 2. The switching element Q1 of the power control circuit 7 is on / off controlled so that the lamp power Wla to be reduced is smaller than the predetermined value. By thus reducing the power supplied to the light source 2, the light output of the light source 2 becomes lower than the prescribed value phi _0.

  In the above-described embodiment, an example in which a high-intensity discharge lamp is used as the light source 2 has been described. However, the present invention is not limited to a high-intensity discharge lamp, and the magnitude of electric power supplied to itself, such as a fluorescent lamp, When the reflected light source 2 is used, a circuit similar to that in the above embodiment can be employed.

  Other configurations and functions are the same as those of the first embodiment.

  By the way, by providing the light source lighting device 1 in each of the above-described embodiments in a fixture main body (not shown) of a lighting fixture (DC device 102), for example, indoor lighting that is attached to a ceiling or a wall or the like to illuminate the interior, The light source lighting device 1 of the present invention can be used in various lighting fixtures such as a foot lamp that is attached to the lower part of the floor and irradiates light on a part of the floor surface. Furthermore, if a plurality of the lighting fixtures are connected to the DC supply line Wdc, an illumination system K102 capable of illuminating a wide range can be constructed. In this case, when a plurality of luminaires are connected to the same DC supply line Wdc, the input voltage Vin from the DC supply line Vin to the other luminaires decreases when a certain luminaire is turned on. However, by adopting the light source lighting device 1 described above, when the input voltage Vin decreases, the input voltage Vin can be prevented from further decreasing.

1 shows Embodiment 1 of the present invention, (a) is a schematic configuration diagram, and (b) is an operation explanatory diagram. FIG. It is a system configuration diagram showing a DC power distribution system in which the light source lighting device is used. It is a schematic circuit diagram which shows a structure same as the above. It is operation | movement explanatory drawing same as the above. It is a schematic circuit diagram which shows the structure of Embodiment 2 of this invention. It is operation | movement explanatory drawing same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source lighting device 2 Light source 4 Detection part (detection means)
6 Control unit (control means)
102 DC equipment (lighting equipment)
E DC power supply Ila Lamp current K102, K105 Lighting system V ₁ First voltage V ₂ Second voltage V ₃ Third voltage Vin Input voltage Wdc DC supply line Wla Lamp power φ ₀ Specified value

Claims (7)

Supplied with electric power from this direct current power supply is connected to the DC power source via a pair of DC supply line, a light source lighting device for lighting a light source the magnitude of the current flowing through the self is reflected in the size of the light output A step-down chopper circuit for controlling a current flowing to the light source, a detecting means for detecting a voltage input from the DC supply line to the step-down chopper circuit as an input voltage, and an input when the input voltage is equal to or higher than the first voltage. Control means for controlling the step-down chopper circuit so that the current flowing through the light source is maintained at a predetermined value regardless of voltage fluctuations, and the current flowing through the light source becomes smaller than the predetermined value when the input voltage falls below the first voltage. A light source lighting device comprising: The light source lighting device according to claim 1 , wherein the control unit determines a reduction amount from the predetermined value of a current flowing through the light source in accordance with a reduction amount of the input voltage from the first voltage. . 3. The light source lighting device according to claim 1 , wherein the control unit turns off the light source when the input voltage falls below a second voltage lower than the first voltage . 4. 4. The control unit according to claim 1 , wherein the light source is turned off when the input voltage exceeds a third voltage that is higher than the first voltage . 5. Light source lighting device. The light source lighting device according to any one of claims 1 to 4, wherein an output voltage of the DC power supply is 50 V or less . An illumination fixture comprising: a light source lighting device according to the instrument body in any one of claims 1 to 5. A lighting system comprising a plurality of lighting fixtures according to claim 6 .

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