KR20130109744A - Dc dimmable ballst and dimmer switch for dc distribution systems - Google Patents

Abstract

PURPOSE: A DC dimming stabilizer for DC distribution and a DC dimming switch easily control the on, off, and dimming of multiple lamps by only with one DC diming switch. CONSTITUTION: A DC dimming stabilizer (3) includes an input voltage dimming control unit (33), a stabilizer unit (32), and an auxiliary power unit (31). The input voltage dimming control unit generates a signal to control the illuminance of a lamp according to input voltages. The stabilizer unit drives a lighting device by receiving a DC variable voltage. The auxiliary power unit provides a specific voltage corresponding to a wide input voltage range as auxiliary power of the stabilizer unit. A DC dimming switch (2) receives a DC distribution voltage (1) and outputs the DC variable voltage. [Reference numerals] (1) DC distribution voltage; (2) DC dimming switch; (26) Control unit; (27) Dimming setting unit; (28) External device; (29) DC converter unit; (3,EE) DC dimming stabilizer; (31) Auxiliary power unit; (32) Stabilizer unit; (33) Input voltage dimming control unit; (AA) Voltage feedback; (BB) DC adjustable voltage; (CC) Lamp #1; (DD) Feed back; (FF) Lamp #2

Description

DC dimmable ballst and dimmer switch for DC distribution systems}

The present invention converts the DC distribution voltage of at least 100V or more generated by the DC distribution voltage or the AC / DC rectifier of the pre-installed DC distribution system to a variable DC voltage through a DC dimming switch, to adjust the illuminance of the lamp according to the DC input voltage The present invention relates to a lighting control system capable of adjusting illuminance by supplying a DC dimming ballast having a light intensity.

Conventionally, an AC distribution system centered on a commercial power source has been generally used to supply power to various electric appliances. In recent years, DC distributed power supplies using solar cells (photovoltaic power generation), fuel cells, storage batteries, and the like have become popular. In addition, in order to reduce the power loss at the time of converting AC power in each electric device into DC power, introduction of the DC power distribution system is also proposed. In particular, the lighting ballast has a double conversion process of converting the AC input into DC power, and converts it back into DC power or AC power required for the lamp. The introduction of a DC power distribution system enables the conversion of direct current to the voltage required for a lamp without the conversion process of alternating current to direct current, thereby improving the efficiency and size of the ballast. In addition, since power fluctuations having twice the frequency of the AC input voltage frequency (for example, 120 Hz) do not occur, it is possible to configure such that the low frequency electrolytic capacitor for filtering the 120 Hz power fluctuations is not used in the ballast. It can extend the life.

In addition, the dimming ballast used in the conventional lighting control system is analog type (0 ~ 10V) or digital type (wired communication method-DALI, RS485, etc.). Use the way. Accordingly, additional signal lines need to be additionally installed, which makes the construction and installation complicated. Especially, it is very difficult to replace the centralized dimming system in an existing building. Recently, a dimming method using a wireless communication module (ZIGBEE, WIFI, PLC, etc.) has been proposed, but even in this method, since the communication module must be installed in each ballast, the price increases, and the standby power supplied to the communication module is generated. There is a disadvantage that the system efficiency is reduced.

In order to overcome the above disadvantages, in the present invention, by configuring the premises lighting distribution as a DC distribution system, the flicker due to the ripple corresponding to twice the AC input voltage frequency without using an electrolytic capacitor which is a low-life component in the lighting ballast located in the luminaire. The ballast can be removed, and the ballast can be configured by only one-step power conversion, so that the power conversion efficiency of the ballast can be increased, thereby reducing the size of the ballast embedded in the luminaire.

 In addition, since the distribution voltage of the premises is DC, a variable DC voltage can be obtained simply through the DC dimming switch proposed in the present invention, and this voltage is supplied to the DC dimming ballast, and in the DC dimming ballast, a variable input voltage level is used as a dimming signal. It is possible. Therefore, it is possible to remove signal lines for separate dimming, which simplifies the installation of the entire lighting control system and the replacement of the existing lighting system. Conventionally, a dimming ballast of a PLC method or a wireless communication method using a power line as a control signal line exists in order not to use a signal line. However, since the communication module must be installed in each ballast, the price increases and the size of the ballast increases. In other words, there is a disadvantage that standby power is generated for communication even when it is off.

In the existing AC system, there is a case that the illuminance is controlled by varying the effective value of the input voltage through the existing triac dimmer without a separate dimming line. In addition, a method of dimming by using a triac dimmer in an existing AC distribution using a special circuit is also proposed for bulb type fluorescent lamps, LED bulbs, and LED fluorescent lamp ballasts. In order to cope with the triac dimmer, additionally, a damping circuit that blocks the inrush current at the time the triac turns on, and a face decoder circuit and a bleeder circuit must be added to maintain the proper holding current during the triac off section. This rises and the power conversion efficiency is lowered compared to the general ballast. Therefore, it is only applicable to individual bulb type lamps of less than 10W, and is difficult to apply to large-scale lighting control systems.

An object of the present invention is to supply the lighting wiring by the DC distribution system in order to solve the problems such as low life and low efficiency of the lighting ballast in the conventional AC distribution system, to eliminate the separate communication line used in the conventional dimming control method DC lighting control system with a dimming function to adjust the illuminance of the lamp by installing a DC dimming ballast with a function of varying the magnitude of the DC output voltage with a DC dimming switch and dimming according to the magnitude of the input voltage. To provide.

Still another object of the present invention is to control the DC voltage of one DC dimming switch supplied to a plurality of lamps to turn on / off or dimming the plurality of lamps, thereby eliminating the need for a separate dimming signal line. The present invention provides a lighting control system that can be easily modified.

In addition, the output voltage of the DC dimming switch proposed in the present invention is variably controlled by the lighting voltage and the dimming voltage, and the DC variable voltage, which is the output of the DC dimming switch, is supplied to a general fluorescent ballast and a discharge lamp electronic ballast used in an existing AC distribution system. By doing so, it is possible to control the illuminance of the fluorescent lamp and the discharge lamp through the DC voltage control of the ballast without changing the shape of the lighting system network even in the place where the existing fluorescent lamp is used. In addition, according to the allowable capacity of the apparatus according to the present invention, power can be simultaneously supplied to a plurality of ballasts without changing the existing system configuration, thereby enabling batch on / off control, batch dimming, and the like.

The DC dimming ballast according to the present invention is a DC dimming ballast for generating a driving power for driving while receiving the DC variable voltage supplied from the outside to adjust the brightness of the lamp, the drive for driving the lamp by receiving the DC variable voltage An electronic ballast that outputs power but controls the output using an output feedback loop; An input voltage dimming control unit for detecting a DC variable voltage and generating a dimming control signal dependent on the detected voltage to perform a dimming function of adjusting the output of the lamp according to the detected voltage; And an auxiliary power supply unit configured to receive a DC variable voltage and generate an auxiliary power having a predetermined size, and supply the auxiliary power supply to the electronic ballast to be used as a control power supply of the electronic ballast.

The input voltage dimming controller may include: a detector configured to detect a DC variable voltage and generate an input voltage which is a detected voltage; And a dimming control signal generator configured to generate a control signal for dimming so as to vary an output of the electronic ballast according to a difference between the detected input voltage and the dimming start voltage, which is a reference voltage for dimming.

The electronic ballast includes a digital lamp power control unit for digitally controlling the lamp power, and the dimming control signal generator adjusts the current command value of the digital lamp power control unit according to the detected input voltage to vary the output of the ballast. Can be digital.

The auxiliary power supply may use a switching type converter to generate a voltage having a constant magnitude in response to the voltage variation of the DC variable voltage.

The direct current dimming ballast does not include an electrolytic capacitor but may use a film or ceramic capacitor.

The DC dimming switch according to the present invention is a DC dimming switch used in a DC distribution system to receive a DC distribution voltage and output a DC variable voltage to provide a power source for driving a lighting device. A dimming setting unit for changing a signal to an output voltage command value; A DC converter that receives the DC distribution voltage and outputs a DC variable voltage, and outputs a variable output voltage according to an output voltage command value of the dimming setting unit; And a control unit which receives a DC variable voltage, which is an output voltage of the DC converter unit, and compares the DC variable voltage with a voltage command value of the dimming setting unit to control the DC converter unit so that the DC variable voltage becomes a desired value.

The control unit may include a function of blocking an output of the DC converter unit according to an on / off signal and a function of blocking an overcurrent by detecting a current of the DC converter unit.

The lighting control system according to the present invention is a lighting control system including the DC dimming switch and an electronic ballast for fluorescent lamps, wherein the electronic ballast for fluorescent lamps receives a DC variable voltage which is an output of the DC dimming switch to drive a lamp. Instead of including a loop, the dimming function is performed by varying the DC variable voltage of the DC dimming switch.

The DC dimming switch maintains the magnitude of the DC variable voltage to be a lighting voltage of sufficient magnitude for a certain time when the lighting is lit, and can be adjusted by lowering the DC variable voltage to the desired illuminance during the illumination control period after lighting.

Lighting control system according to the present invention is a DC dimming lighting control system for controlling the lighting including the DC dimming ballast and the DC dimming switch, the DC dimming ballast receives the DC variable voltage which is the output of the DC dimming switch It characterized in that to drive.

The lighting control system may perform a dimming function using the magnitude of the DC variable voltage instead of using a separate communication means for transmitting a signal for dimming received from the outside to the DC dimming ballast.

As described above, in the present invention, a plurality of lamps may be easily turned on and off by one DC dimming switch. In addition, in the present invention, by using a DC distribution voltage, it is possible to replace a long life film or ceramic capacitor instead of using a low life electrolytic capacitor that prevents 120 Hz flicker in the ballast regardless of the type of the ballast. Long life ballast is possible. In addition, by removing the AC direct current conversion part in the ballast, and performing only one-step power conversion, the efficiency of the ballast mounted in the luminaire increases, it is possible to reduce the size compared to the existing ballast.

The DC dimming switch and DC dimming ballast proposed in the present invention can be used by making a DC distribution voltage by installing a separate unidirectional AC / DC rectifier in the AC distribution system as well as a place equipped with a DC distribution system.

In particular, in a system equipped with renewable energy sources such as solar light and fuel cell, if the DC dimming switch and DC dimming ballast of the present invention are used, the DC power generated from the renewable energy source is used in direct DC form without changing to AC power. This makes it possible to increase the efficiency of the overall system. In this case, when the energy of the renewable energy source is greater than the lighting energy, the AC / DC bidirectional rectifier and the energy storage device may be used in parallel.

DC dimming ballast of the present invention can be implemented in any of the analog method of adding the input voltage dimming control unit to the conventional analog feedback type ballast and the digital method of varying the output current by adding the input voltage detector to the digital controller. As a result, dimming is possible without attaching a dimming signal line to the ballasts such as LED and high-pressure discharge lamps, and it is easy to install new and easily replace and install existing lighting wiring system. In addition, if the output characteristics of the DC dimming switch is set to match the existing fluorescent ballast, dimming of the existing fluorescent lamp is possible.

1 is a configuration diagram of a lighting control system composed of a DC dimming switch 2 and a DC dimming ballast 3 according to the present invention.
2 is a detailed embodiment of the DC dimming switch 2 proposed in the present invention.
FIG. 3 shows a specific embodiment of a DC dimming ballast 3 in which an input voltage dimming control part 33 and a switching type auxiliary power supply 31 are added to a flyback LED ballast part 32 which is generally used.
4 illustrates the principle that the dimming operation is implemented by the operation of the input voltage dimming control unit 33 proposed in the present invention.
5 is an embodiment of implementing a DC dimming ballast (3) according to the present invention in a high-pressure discharge lamp that is commonly used.
Figure 6 is an embodiment used in combination with a conventional DC dimming switch 2 according to the present invention and a fluorescent electronic ballast for alternating current widely used.
7 is an embodiment of a control method for using the DC dimming switch 2 of the present invention in the conventional electronic ballast for high pressure lamp.

A direct current dimming switch, a direct current dimming ballast, and a lighting control system including the same according to an embodiment of the present invention will be described with reference to the drawings.

1 is a configuration diagram of a lighting control system composed of a DC dimming switch 2 and a DC dimming ballast 3 according to the present invention.

The DC distribution voltage 1 uses the DC distribution voltage of the DC distribution system, the output voltage of renewable energy, or the output of the AC / DC rectifier installed in the AC distribution system, and usually constitutes at least DC 100V or more. When the output of renewable energy such as sunlight is connected to the DC distribution voltage (1) it may be controlled by using a bidirectional AC / DC rectifier (DC).

The DC dimming switch 2 receives a DC distribution voltage 1 and outputs a DC variable voltage. This DC variable voltage is input to the DC dimming ballast 3 at the rear stage and used as a power source for lighting equipment such as lamps.

To this end, the DC dimming switch 2 receives the dimming signal of the external device 28 and generates a command value of the DC variable voltage. The dimming setting unit 27 compares the voltage command value and the voltage feedback value to control the output voltage. The control unit 26 may include a DC converter 29 that provides a DC variable voltage by varying the DC distribution voltage 1 to a voltage according to the command of the control unit 26.

The DC dimming switch 2 may be connected to an external device to receive a signal for dimming, and may also be connected to a central lighting control system using general wired or wireless communication means to exchange dimming control signals.

The DC dimming switch 2 can be used as a part of the DC lighting control device in the DC distribution panel in the central control type, and can be connected to the illumination sensor in the sensor input method to perform local dimming. It is also connected to the program switch and program dimmer for manual adjustment. In small systems, installing a dimming switch (2) on an existing wall switch for lighting can also utilize the lighting equipment for an AC distribution system.

The DC dimming switch 2 may be connected to an external device 28 such as a sensor for dimming and a dimming indicating means, and the external device may be an illuminance sensor, a far infrared sensor, a program switch, a program dimmer, a remote control switch, a remote control dimmer, a manual dimmer And one or more of the like.

The control unit 26 of the DC dimming switch 2 may perform a function of blocking the output of the DC converter unit according to the on / off signal, and the magnitude of the current detected through the current detection resistor 25 exceeds a normal value. In this case, the overcurrent blocking function may be performed by stopping the operation of the converter.

The DC dimming ballast 3 receives a DC variable voltage that is an output of the DC dimming switch 2 and drives a lighting device such as a lamp.

The DC dimming ballast 3 includes an input voltage dimming control unit 33 for generating a signal for adjusting the illuminance of the lamp according to the input voltage, a ballast unit 32 for driving the luminaire by receiving a DC variable voltage, and a wide input. Auxiliary power supply unit 31 of a linear or switching method for providing a constant voltage to the auxiliary power supply of the ballast 32 in response to the voltage range may be included.

The ballast 32 may use an existing ballast control method. When the luminaire is an LED lamp, the ballast 32 controls the current of the lamp according to the current feedback. When the luminaire is a high-pressure discharge lamp, the ballast 32 may control the power of the lamp according to the power feedback.

At least one DC dimming ballast 3 may be connected to the DC variable voltage, and the DC dimming ballast 3 may be applied to a method of controlling the feedback by controlling an output such as an LED lamp and a high voltage discharge lamp. In addition, if the proper DC variable voltage is adopted, it can be applied to the fluorescent ballast which does not have the output feedback control used in the existing AC distribution. In this case, the fluorescent ballast can act as the DC dimming ballast and can be dimmed to a certain range. .

2 is a detailed embodiment of the DC dimming switch 2 proposed in the present invention.

The DC converter unit 29 of the DC dimming switch 2 may include a switching element 21 such as a MOSFET, a diode 22, an inductor 23, and a capacitor 24. The DC converter 29 converts the DC distribution voltage 1 into a DC variable voltage having a desired size by a switching method of turning on / off the switching element 21 under the control of the controller 26.

The control unit 26 detects the direct current variable voltage which is the output voltage of the direct current dimming switch 2, and controls the switching element 21 of the direct current converter so that the direct current variable voltage becomes a desired value according to the command value of the dimming setting unit 27. To control. The control unit 26 may use a conventional analog IC or may perform digital control.

The dimming setting unit 27 changes the dimming command coming from the external device 28 to the voltage command value of the controller. The dimming setting unit 27 may receive an analog dimming signal (0 to 10V) or a PWM dimming signal and the like, and can cope with wired digital communication (RS485, DALI, etc.) and wireless communication.

FIG. 3 shows a specific embodiment of a DC dimming ballast 3 in which an input voltage dimming control part 33 and a switching type auxiliary power supply 31 are added to a flyback LED ballast part 32 which is generally used.

The ballast section 32 may include an input high frequency filter capacitor C1, a switching element Q1 (such as a MOSFET), an insulation transformer TR1, a diode D1, an output side filter capacitor C2, and a current detection resistor Rs.

Capacitors C1 and C2 generally require very large capacitance electrolytic capacitors to compensate for 120 Hz ripple in AC distribution systems, but in the present invention, small capacity film capacitors or ceramic capacitors may be used.

The current / voltage control IC (U3) detects the current of the LED lamp and controls the constant current or the primary PWM control IC through the photocoupler (U2) to detect and control the voltage applied to the LED lamp. The control signal is transmitted to U1 to enable the PWM control IC U1 to perform the feedback control function.

The input voltage dimming controller 33 includes an input voltage detector and a dimming control signal generator for generating a control signal for dimming. The detector may generate an input detection voltage obtained by dividing the DC variable voltage through a voltage dividing circuit that reduces the size so that the input voltage may be used as a control signal. As the voltage dividing circuit, a resistor voltage dividing circuit such as resistors Ra and Rb of FIG. 3 or a voltage dividing circuit using a capacitor may be used.

The dimming control signal generator of the input voltage dimming control unit 33 functions to generate a control signal for dimming by calculating a difference between the input detection voltage and the reference voltage (for setting the dimming start voltage). For example, as shown in FIG. 3, a dimming control signal that is dependent on a difference between an input detection voltage and a dimming start voltage is generated by using an amplifier U4 and a subtractor including resistors R1, R2, R3, and R4. By using the dimming control signal, the dimming function can be performed by adjusting the control voltage of the control terminal of the general PWM control IC U1. As an example, the output terminal of the subtractor U4 is connected to the base terminal of the PNP transistor Q2, and the editor terminal of the PNP transistor Q2 is connected to the control terminal of the PWM control IC U1. The LED lamp can be dimmed by adjusting the voltage at the control terminal.

The DC dimming ballast 3 can start dimming from a desired voltage by adjusting a reference voltage for setting the dimming start voltage, and dimming start voltage by adjusting the resistance values R1, R2, R3, and R4 of the subtractor. The dimming gain can also be adjusted to determine how sensitive the dimming degree is to vary with the difference between the over and dc variable voltages.

The auxiliary power unit 31 may be a linear method which is generally used as a control power supply for the PWM control IC U1. However, in the present invention, the auxiliary power supply unit of the switching method is used to maintain a constant control power even in a wide range of DC variable voltages. Preference is given to using 31).

4 illustrates the principle that the dimming operation is implemented by the operation of the input voltage dimming control unit 33 proposed in the present invention. The horizontal axis represents the input voltage (the voltage of which the DC variable voltage is detected by a detection circuit such as voltage divider Ra, Rb, etc.), and the vertical axis represents the lamp output, and how the lamp output changes according to the magnitude of the input voltage that detects the DC variable voltage. It is a figure explaining. When the input voltage detecting the DC variable voltage is higher than the dimming start voltage, the input voltage dimming control unit 33 does not affect the lamp output, and the lamp ballast unit 32 controls the lamp at the constant output in the same manner as the existing ballast. . Once the input voltage is lower than the dimming start voltage, the subtractor of the input voltage dimming control unit 33 and the transistor Q2 adjust the control voltage of the PWM control IC U1 as described above, thereby reducing the lamp power and dimming operation is performed. Is implemented. When the input voltage is lowered below the cutoff voltage, the output of the subtractor goes low and the driving of the lamp is blocked because the voltage of the control terminal of the PWM control IC U1 is made low through the transistor Q2. Applying such a method to a commonly used straight-type LED lamp (20W ~ 24W) can drive the lamp to have a wide dimming range of about 100: 1 (20W ~ 0.2W). In this embodiment, the embodiment in which the input voltage dimming control unit 33 is implemented using an analog circuit has been described. However, a configuration that operates on the same principle may be implemented in a digital manner.

5 is an embodiment of implementing a DC dimming ballast (3) according to the present invention in a high-pressure discharge lamp that is commonly used.

In the AC distribution system, the AC input voltage is converted into a DC voltage through a power factor control converter, and the DC voltage is supplied to the DC dimming ballast (3). In this case, a large electrolytic capacitor must be used for the input capacitor (C) to suppress 120Hz ripple. Since the power factor control converter is unnecessary in the DC power distribution system, it is not necessary to use a large capacity electrolytic capacitor, and a small film or ceramic capacitor can be used for the input capacitor C.

The function of the input voltage dimming controller 33 according to the present invention described in FIG. 4 may be implemented in the digital lamp power controller 35 included in the ballast for a general high voltage discharge lamp. A part for detecting an input voltage is added to the digital lamp power controller 35 and the algorithm is modified to control lamp power according to the input voltage of FIG. 4 to the lamp power control algorithm (having the same function as the input voltage dimming controller 33). Can be implemented.

In general, an electronic ballast of a high voltage discharge lamp detects a lamp voltage in a digital lamp power controller, generates a current command value for constant power control, and controls a current of the high voltage discharge lamp by controlling a current of a buck converter. In the present invention, the input voltage detection is added to the digital lamp power control unit of the normal high-voltage discharge lamp, and the constant output control is performed in a predetermined voltage range as shown in FIG. 4, and the current command value of the current control unit is adjusted when the input voltage falls below the dimming start voltage. Begin dimming the high-pressure discharge lamp, and then dimming to the lowest arc holding power (typically 50%) of the high-voltage discharge lamp. It can be programmed to stop driving the lamp when the input voltage falls below the breaking voltage. The dimming start voltage and cutoff voltage can be adjusted using parameter values in the program.

Figure 6 is an embodiment used in combination with a conventional DC dimming switch 2 according to the present invention and a fluorescent electronic ballast for alternating current widely used. In general, a fluorescent electronic ballast without a constant current feedback control loop inside operates in a manner that the amount of light in the lamp decreases when the input voltage decreases. By using this advantage, if the direct current dimming switch (2) according to the present invention to make a DC variable voltage and supply to the existing alternating current fluorescent electronic ballast is possible fluorescent dimming. In the case of ordinary fluorescent lamps, dimming is possible in the range of about 10: 1.

7 is an embodiment of a control method for using the DC dimming switch 2 of the present invention in the conventional electronic ballast for high pressure lamp. In order to surely turn on the high voltage lamp, it is desirable to apply a high voltage higher than the normal sustain voltage or the voltage at dimming at the beginning of the lighting. To this end, during the constant lighting time when the light switch is turned on, the DC dimming switch 2 supplies a lighting voltage greater than the dimming voltage to ensure reliable lighting, and to change the dimming voltage for dimming after a predetermined time. desirable. In the case of high-pressure discharge lamps, dimming is possible in the range of about 5: 1.

Although preferred embodiments of the present invention have been described above, these are just examples, and the present invention is not limited thereto, and may be modified and implemented in various ways. Further, additional technical features may be added based on the disclosed technical idea. It will be obvious that it can be implemented.

1: DC distribution voltage
2: DC dimming switch
3: DC dimming ballast
26:
27: dimming setting section
28: external device
29: DC converter section
31: auxiliary power unit
32: ballast part
33: input voltage dimming control unit

Claims (11)

DC dimming ballast which generates driving power to drive the lamp while adjusting the brightness by receiving the DC variable voltage supplied from the outside,
An electronic ballast configured to receive a DC variable voltage and output driving power for driving the lamp, and to control the output by using an output feedback loop;
An input voltage dimming control unit for detecting a DC variable voltage and generating a dimming control signal dependent on the detected voltage to perform a dimming function of adjusting the output of the lamp according to the detected voltage; And
An auxiliary power supply unit configured to receive a DC variable voltage and generate an auxiliary power having a predetermined size and supply the electronic ballast to be used as a power source of the electronic ballast;
DC dimming ballast, characterized in that it comprises a.
The method of claim 1,
The input voltage dimming control unit,
A detector for detecting a DC variable voltage and generating an input voltage which is a detected voltage; And
A dimming control signal generator configured to generate a control signal for dimming to vary an output of the electronic ballast according to a difference between the detected input voltage and the dimming start voltage, which is a reference voltage for dimming;
DC dimming ballast, characterized in that it further comprises.
3. The method of claim 2,
The electronic ballast includes a digital lamp power control unit for digitally controlling the lamp power,
The dimming control signal generator is a digital dimming ballast, characterized in that the digital method for varying the output of the ballast by adjusting the current command value of the digital lamp power control unit in accordance with the detected input voltage.
4. The method according to any one of claims 1 to 3,
The auxiliary power supply unit DC dimming ballast, characterized in that for using a switching type converter to generate a voltage of a constant magnitude in response to the voltage variation of the DC variable voltage.
4. The method according to any one of claims 1 to 3,
The DC dimming ballast does not include an electrolytic capacitor, DC dimming ballast, characterized in that using a film or ceramic capacitor.
DC dimming switch which is used in DC distribution system and receives DC distribution voltage and outputs DC variable voltage to provide power for driving lighting device.
A dimming setting unit for changing a signal for dimming provided from an external device into an output voltage command value;
A DC converter that receives the DC distribution voltage and outputs a DC variable voltage, and outputs a variable output voltage according to an output voltage command value of the dimming setting unit; And
A control unit which receives a DC variable voltage, which is an output voltage of the DC converter unit, and compares the DC variable voltage with a voltage command value of the dimming setting unit to control the DC converter unit such that the DC variable voltage becomes a desired value;
DC dimming switch comprising a.
The method according to claim 6,
And the control unit includes a function of blocking an output of the DC converter unit in response to an on / off signal and a function of detecting an overcurrent by detecting a current of the DC converter unit.
An illumination control system comprising the DC dimming switch of claim 6 and an electronic ballast for fluorescent lamps,
The electronic ballast for the fluorescent lamp receives a DC variable voltage, which is an output of the DC dimming switch, and drives a lamp, but does not include a feedback loop, but performs a dimming function by varying the DC variable voltage of the DC dimming switch. Lighting control system.
The method of claim 8,
The DC dimming switch maintains the magnitude of the DC variable voltage to be a lighting voltage of sufficient magnitude for a predetermined time when the lighting is lit, and lowers and adjusts the DC variable voltage to the desired illuminance during the illumination control period after the lighting. Lighting control system.
A direct current dimming lighting control system comprising a direct current dimming ballast of claim 1 and a direct current dimming switch of claim 6 to control illumination.
The DC dimming ballast is DC dimming lighting control system, characterized in that for driving the illumination by receiving a DC variable voltage that is the output of the DC dimming switch.
The method of claim 10,
The lighting control system does not use a separate communication means to transfer a signal for dimming received from the outside to the DC dimming ballast, instead of performing a dimming function using the magnitude of the DC variable voltage. Lighting control system.

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