JP2009158114A - Light source lighting device, illumination fixture, and illumination system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source lighting device, an illumination fixture, and an illumination system capable of lighting a light source by preventing further reduction of an input voltage when the input voltage from a direct current supply line is reduced. <P>SOLUTION: The light source lighting device 1 is connected to a direct current power supply E via the direct current supply line Wdc, and lights on the light source 1 by receiving electric power supply from the direct current power supply E. A voltage input into the light source lighting device 1 from the direct current supply line Wdc is detected as the input voltage Vin by a voltage detecting means, a current input into the light source lighting device 1 from the direct current supply line Wdc is detected as the input current Iin by the electric current detecting means. A control means maintains light output of the light source 2 at a prescribed value regardless of fluctuations of the input voltage Vin when the input voltage Vin is a first voltage V<SB>1</SB>or more, and limits the input current Iin at a limit value I<SB>1</SB>, which is the input current Iin when the input voltage Vin is the first voltage V<SB>1</SB>, or lower, if the input voltage Vin becomes lower than the first voltage V<SB>1</SB>. <P>COPYRIGHT: (C)2009,JPO&INPIT

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 a load connected to the same DC supply line as the light source lighting device does not operate normally due to a decrease in the input voltage. there is a possibility.

  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 is a light source lighting device that is connected to a DC power source via a pair of DC supply lines and that receives power supply from the DC power source to light the light source, and is a voltage input from the DC supply line Voltage detecting means for detecting the input voltage as input voltage, current detecting means for detecting current input from the DC supply line as input current, and when the input voltage is equal to or higher than the first voltage, the light source Control means for limiting the input current below a limit value that is an input current when the input voltage is the first voltage when the optical output is maintained at a specified value and the input voltage falls below the first voltage. Features.

  According to this configuration, when the input voltage is equal to or higher than the first voltage, the control means maintains the light output of the light source at the specified value regardless of the fluctuation of the input voltage, and when the input voltage falls below the first voltage. Since the input current is limited below the limit value that is the input current when the input voltage is the first voltage, the light output of the light source is set to the specified value regardless of the fluctuation of the input voltage when the input voltage is equal to or higher than the first voltage. While maintaining, if the input voltage falls below the first voltage due to a decrease in the input voltage, an increase in the input current from the DC supply line due to the decrease in the input voltage can be suppressed. 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.

  According to a second aspect of the present invention, in the first aspect of the invention, the magnitude of the current flowing through the light source is reflected in the magnitude of the optical output, and the control means is configured such that the input voltage is the first voltage. If the voltage is lower than the voltage, the current flowing to the light source is reduced.

  According to this configuration, the control unit lowers the current flowing through the light source to lower the light output of the light source from a specified value. The invention of claim 1 can be realized by using a light source that reflects the magnitude of the output.

  According to a third aspect of the present invention, in the first aspect of the present invention, the amount of electric power supplied to the light source is reflected in the amount of light output, and the control means is configured so that the input voltage is the input voltage. When the voltage falls below the first voltage, the power supplied to the light source is reduced.

  According to this configuration, the control unit lowers the power supplied to the light source to lower the light output of the light source below a specified value. Therefore, for example, the power supplied to itself such as a high-intensity discharge lamp or a fluorescent lamp. The invention of claim 1 can be realized by using a light source that reflects the size of the light output in the light output.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the control means maintains the input current at the limit value when the input voltage falls below the first voltage. Features.

  According to this configuration, since the input current is fixed when the input voltage from the DC supply line is lower than the first voltage, when the input voltage fluctuates within the range lower than the first voltage, the input voltage is reduced. Along with this, it is possible to minimize fluctuations in the light output of the light source while preventing an increase in the current flowing through the DC supply line.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the control unit turns off the light source when the input voltage falls below a second voltage lower 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 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 sixth aspect of the present invention, in any one of the first to fifth 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 seventh aspect of the present invention, in any one of the first to sixth aspects, the output voltage of the DC power supply 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 8 is characterized in that the fixture body is provided with the light source lighting device according to any one of claims 1 to 7.

  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 ninth aspect of the invention is characterized in that a plurality of lighting fixtures according to the eighth 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, K105, an intercom system K103 including a DC device 102 for handling visitors and monitoring intruders, a residential alarm system K104 including a DC device 102 for an alarm system such as a fire detector, and the like. 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 on 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 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 cooperation control unit 113 performs charge / discharge of the secondary battery 162 and cooperation 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 supply and the distributed power supply constituting the DC power supply unit 101 to the DC devices 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, the cooperative control unit 113 is provided with a DC / DC converter to convert the DC voltage obtained from the main power source and the distributed power source into the 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 for controlling a current flowing through the light source 2 between a pair of DC input terminals T1 and T2 connected to the DC power source E via the DC supply line Wdc, and a DC supply line Wdc. A voltage detector (voltage detector) 4 that detects a voltage applied between the DC input terminals T1 and T2 as an input voltage Vin, and a current that detects a current flowing from the DC supply line Wdc to the current control circuit 3 as an input current Iin. And a detection unit (current detection means) 10.

  The current control circuit 3 includes a series circuit of a switching element Q1, an inductor L1, and a capacitor C1 connected between the DC input terminals T1 and T2 via the current detection unit 10, and a connection point side of the switching element Q1 and the inductor L1. A diode D1 connected between both ends of the series circuit of the inductor L1 and the capacitor C1 so as to connect the cathode to the drive circuit 5, 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 to be described later A step-down chopper circuit having 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 voltage detection unit 4 includes a series circuit of resistors R1 and R2 connected between a pair of DC input terminals T1 and T2, and the control unit 6 determines a DC voltage based on the voltage across the resistor R2 constituting the voltage detection unit 4. The input voltage Vin input to the light source lighting device 1 from the supply line Wdc is monitored.

  The current detection unit 10 includes a resistor R0 connected between one DC input terminal T2 and the anode of the diode D1 of the current control circuit 3, and the control unit 6 determines the DC supply line based on the voltage across the resistor R0. The input current Iin input to the light source lighting device 1 from Wdc is monitored. Here, when the power supplied from the DC supply line Wdc to the light source lighting device 1 is the input power Win, the input power Win is represented by the product of the input voltage Vin and the input current Iin (Win = Vin × Iin).

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 light output of the light source 2 to the specified value regardless of the input voltage Vin is the first input voltage Vin the magnitude of the input current Iin and below the voltages V ₁ a first value when the voltages V ₁ (hereinafter, the limit value referred to) so as to limit the input current Iin to the limit value or less I ₁ by maintaining the I _1, performs on-off control of the switching element Q1 by a drive signal. 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 input voltage Vin detected by the voltage 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 The switching element Q1 of the current control circuit 3 is on / off controlled 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 ( (Specified value). At this time, the input power Win = Vin × Iin (the circuit efficiency is constant) represented by the product of the input voltage Vin and the input current Iin is kept constant. Therefore, the input current is determined by the relationship of Iin = Win / Vin. Iin increases as the input voltage Vin decreases.

On the other hand, when the input voltage Vin detected by the voltage 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 causes the light source 2 to for turning on and off the switching element Q1 of the current control circuit 3 so as to maintain the lamp current Ila to flow magnitude of the input current Iin by less than the predetermined value to limit value I _1. At this time, the input current Iin is kept at the limit value I _1, with an input power Win represented by the product of the input voltage Vin input current Iin is decreased with the decrease of the input voltage Vin, the source 2 The light output is lower than the specified value.

  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 to the light source lighting device 1 from the pair of DC supply lines Wdc is equal to or higher than the _first voltage V1, the light output of the light source 2 regardless of the fluctuation of the input voltage Vin. Can be maintained at a specified value. 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,} limit the input current Iin value (input current Iin when the input voltage Vin is of the first voltage _{V 1)} by keeping the _{I 1,} the DC supply line with decreasing input voltage Vin An increase in the input current Iin from Wdc 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) to reduce the, it is possible to maintain the input current Iin to the limit value I _1, that the input current Iin with the decrease of the input voltage Vin rises as in the case to keep the input power Win constant Can be prevented. 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 decreases when the input voltage Vin falls below the _first voltage V1, the light output indicates that the user is in an abnormal state (the input voltage Vin is decreasing). There is also an advantage that it can be notified by the decrease of

Incidentally, in the present embodiment, as shown in FIG. 1 (b), when the input voltage Vin is within the range from the voltage V ₁ to a second voltage V _2, the input current Iin to the limit value I ₁ since fixed, when the input voltage Vin varies within a range below the first voltage V _1, while preventing the current flowing increases the DC supply line Wdc with a decrease in the input voltage Vin, Variations in the light output of the light source 2 can be minimized. However, the control unit 6, as long as the input voltage Vin is limited to the limit value I ₁ below the input current Iin when below the voltage V ₁ of the said first input voltage Vin as in the present embodiment not limited to the example to maintain the input current Iin to a certain limiting value I ₁ to the extent that the first below the voltages V _1, for example, the input current Iin with a decrease amount from the first voltage V ₁ at the input voltage Vin it may be to lower the limit value I _1.

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 voltage detection unit 4, a resistor R 0 as a current detection unit 10, and a power control circuit 7 that controls the amount of power supplied to the light source 2 between the DC input terminals T 1 and T 2. And a power conversion circuit 8 that converts the DC power output from the power control circuit 7 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. is doing.

  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 when the switching elements Q3 and Q4 are on and a period when the switching elements Q2 and Q5 are off, thereby connecting the connection point between the switching elements Q2 and Q4 and the connection point between the 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 controlled to be turned on and off 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 the present embodiment, the input voltage Vin detected by the voltage detector 4 is not less than the first voltage V _{1 and not} more than the third voltage V ₃ (V ₁ ≦ Vin ≦ V ₃ ). At this time, the control unit 6 performs on / off control of 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). 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. The light output is maintained constant (specified value). At this time, since the input power Win represented by the product of the input voltage Vin and the input current Iin is kept constant, the input current Iin increases with a decrease in the input voltage Vin due to the relationship of Iin = Win / Vin.

On the other hand, when the input voltage Vin detected by the voltage 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 moves to the light source 2. power control to maintain the lamp power Wla supplied to the input current Iin is limiting value I ₁ when the input current Iin by less than a predetermined value the magnitude of the input voltage Vin is first voltages V ₁ The switching element Q1 of the circuit 7 is on / off controlled. At this time, the input current Iin is kept at the limit value I _1, with an input power Win represented by the product of the input voltage Vin input current Iin is decreased with the decrease of the input voltage Vin, the source 2 The light output is lower than the specified value.

  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 a schematic circuit diagram which shows the structure of Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source lighting device 2 Light source 4 Voltage detection part (voltage detection means)
6 Control unit (control means)
10 Current detector (current detection means)
102 DC equipment (lighting equipment)
E DC power source Iin Input current I ₁ Limit value Ila Lamp current K102, K105 Lighting system R0 Resistance V ₁ First voltage V ₂ Second voltage V ₃ Third voltage Vin Input voltage Wdc DC supply line Wla Lamp power

Claims (9)

  A light source lighting device that is connected to a DC power source via a pair of DC supply lines and that receives power supplied from the DC power source to light a light source, and detects a voltage input from the DC supply line as an input voltage Detection means, current detection means for detecting the current input from the DC supply line as an input current, and maintaining the light output of the light source at a specified value regardless of fluctuations in the input voltage when the input voltage is equal to or higher than the first voltage And a control means for limiting the input current to a limit value that is an input current when the input voltage is the first voltage when the input voltage falls below the first voltage.   The light source reflects the magnitude of the current flowing through the light source in the magnitude of the light output, and the control means reduces the current passed through the light source when the input voltage falls below the first voltage. The light source lighting device according to claim 1.   The light source reflects the magnitude of power supplied to itself in the magnitude of light output, and the control means reduces the power supplied to the light source when the input voltage falls below the first voltage. The light source lighting device according to claim 1, wherein:   4. The light source lighting device according to claim 1, wherein the control unit maintains the input current at the limit value when the input voltage falls below the first voltage. 5. .   5. The control unit according to claim 1, wherein the light source is turned off when the input voltage falls below a second voltage lower than the first voltage. 6. Light source lighting device.   6. The control unit according to claim 1, wherein the control unit turns off the light source when the input voltage exceeds a third voltage that is higher than the first voltage. 7. Light source lighting device.   The light source lighting device according to any one of claims 1 to 6, wherein an output voltage of the DC power supply is 50 V or less.   A lighting fixture comprising the light source lighting device according to any one of claims 1 to 7 in a fixture main body.   A lighting system comprising a plurality of lighting fixtures according to claim 8.

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