JP2013132198A - Lighting control device and lighting apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting control device capable of controlling an output current and improving a power factor with a further simple configuration, and to provide a lighting apparatus using the same.SOLUTION: A lighting control device includes: a full-wave rectification element 2 full-wave rectifying a sinusoidal AC voltage and generating a full-wave rectification voltage; a switching circuit 5 including a switching element SW1, a capacitor C2, and an inductor L1, and converting the full-wave rectification voltage into a predetermined DC voltage V2; a first detection section R3 detecting a peak current of an output current of the switching circuit 5 by current-voltage conversion; a second detection section R4 detecting a bottom current of an output current of the switching circuit 5 by current-voltage conversion; a threshold-value creation section 3 creating a threshold value that increases and decreases according to increase and decrease of the amplitude of the full-wave rectification voltage; and a control section 4 controlling on and off of the switching element SW1. The control section 4 turns off the switching element SW1 when a detection voltage by the first detection section reaches the threshold value, and turns on the switching element SW1 when a detection voltage by the second detection section reaches zero.

Description

  The present invention relates to a lighting control device that controls lighting of a plurality of light emitting elements, and a lighting fixture using the same.

  In recent years, light-emitting elements composed of light-emitting diodes (LEDs) have been widely used in lighting fixtures as light sources. This luminaire includes a plurality of light emitting elements and a lighting control device that controls lighting of the plurality of light emitting elements in order to obtain predetermined brightness (illuminance).

  The plurality of light emitting elements are generally electrically connected by series connection or series-parallel connection. The lighting control device can control light output from the plurality of light emitting elements by performing constant voltage control or constant current control on the plurality of light emitting elements. However, the forward voltage of each light emitting element varies. Therefore, the lighting control device can control the light output from the plurality of light emitting elements by performing constant current control on the plurality of light emitting elements when the plurality of light emitting elements are electrically connected in series. It becomes possible.

  Also, since the input voltage of the above-mentioned lighting fixture is often an AC voltage from a commercial power supply, the power factor is improved by synchronizing the waveform of the input current with the waveform of the input voltage, and the transmitted energy is maximized. Is desirable. In addition, for lighting fixtures that use an AC voltage from a commercial power supply as an input voltage, harmonic regulations (for example, JIS C 61000-3-2) are prescribed for waveform distortion of the input current. Need to be satisfied.

  Therefore, the lighting control device is required to have a function of controlling light output from the plurality of light emitting elements and a function of improving the power factor.

  Conventionally, there has been proposed a digital power converter that can simultaneously control both the current flowing through the LED and correct the power factor of the input power (Patent Document 1).

  As shown in FIG. 10, the digital power converter disclosed in Patent Document 1 is a single-stage power converter, and includes an EMI filter 44, a rectifier 46, and a power block 48. An AC power supply is connected to the input end of the EMI filter 44. In the power block 48, a plurality of LEDs 42 are connected between the pair of output terminals 49a and 49b.

  The power block 48 includes a power switch 41 made of a MOSFET, a gate driver 43 that drives the gate of the power switch 41, and a controller 45 that controls the driving of the power switch 41 by the gate driver 43.

  As shown in FIG. 11, the controller 45 includes a sine table module 50, a multiplication module 51, an addition module 52, an A / D converter 53, a clock generation module 54, a PID module 55, a PWM control module 56, a delay counter 57, and a comparator. 58.

Special table 2008-537459 gazette

  In the digital power converter disclosed in Patent Document 1, both control of the current flowing in the LED and power factor correction (power factor improvement) of the input power can be obtained simultaneously. In addition, this digital power converter is a single-stage power converter, and can be reduced in cost compared to a two-stage power converter including a power factor correction circuit at the front stage and a constant current drive circuit at the rear stage. Is possible.

  However, in the digital power converter disclosed in Patent Document 1, the configuration of the controller 45 is complicated.

  The present invention has been made in view of the above reasons, and an object thereof is to provide a lighting control device capable of controlling the output current with a simpler configuration and improving the power factor, and a lighting fixture using the same. There is to do.

  The lighting control device of the present invention includes a full-wave rectifying element that generates a full-wave rectified voltage by full-wave rectifying a sinusoidal AC voltage, a switching element, a capacitor, and an inductor. A switching circuit that converts a full-wave rectified voltage into a predetermined DC voltage; and a first detection unit that detects a peak current of an output current that is output from the switching circuit and flows through a series circuit of a plurality of light-emitting elements by current-voltage conversion; A second detection unit that detects the bottom current of the output current from the switching circuit by current-voltage conversion, and a threshold that increases or decreases according to an increase or decrease in the amplitude of the full-wave rectified voltage generated by the full-wave rectifier element. A threshold generation unit for generating, and a control unit for controlling on / off of the switching element, wherein the control unit detects the voltage detected by the first detection unit. When it reaches the value, turns off the switching element, voltage detected by the second detection unit when it reaches zero, characterized in that on the switching element.

  In this lighting control device, the threshold generation unit is a resistance voltage dividing circuit configured by a series circuit of a first resistor and a second resistor, and the full-wave rectified voltage generated by the full-wave rectifying element is a resistor. The threshold value is generated by dividing the voltage, and the amplitude corresponding to the increase in the vibration of the full-wave rectified voltage is suppressed in order to suppress fluctuation of the threshold value when the amplitude of the full-wave rectified voltage is larger than a predetermined value. It is preferable to have a suppressing portion that draws a part of the current flowing through one resistor.

  The lighting control device includes a plurality of charging capacitors that are charged during a period when the full-wave rectified voltage is high in the voltage waveform of the full-wave rectified voltage generated by the full-wave rectifier element, It is preferable to have a valley filling circuit that discharges the charging voltages charged in the plurality of charging capacitors to the high potential side of the full-wave rectifying element during a period when the full-wave rectified voltage is low in the voltage waveform.

  In this lighting control device, the output voltage of the switching circuit is preferably a voltage lower than the effective value of the AC voltage.

  In this lighting control device, it is preferable that the output voltage of the switching circuit is equal to or less than half of the effective value of the AC voltage.

  In this lighting control device, the output voltage of the switching circuit is preferably 50 V or less when the effective value of the AC voltage is 100 V.

  In this lighting control device, it is preferable that the switching frequency of the switching element does not include 20 kHz or less.

  The lighting fixture of the present invention includes the plurality of light emitting elements, the lighting control device that controls the lighting of the plurality of light emitting elements, and a fixture main body.

  In the lighting control device of the present invention, the output current can be controlled with a simpler configuration, and the power factor can be improved.

  In the lighting fixture of the present invention, the output current can be controlled with a simpler configuration, and the power factor can be improved.

1 is a schematic circuit diagram illustrating a lighting control device according to a first embodiment. It is explanatory drawing which shows the voltage waveform of a full wave rectification voltage and a threshold voltage regarding the lighting control apparatus same as the above. It is explanatory drawing which shows the current waveform of an output electric current and a threshold current regarding the lighting control apparatus same as the above. It is explanatory drawing which shows the envelope which connected the peak current of the electric current which flows through a 1st detection part regarding the lighting control apparatus same as the above. It is a schematic sectional drawing which shows the structural example of the lighting fixture of Embodiment 1. FIG. It is a schematic circuit diagram which shows the lighting control apparatus of Embodiment 2. It is a schematic circuit diagram which shows the lighting control apparatus of Embodiment 3. It is explanatory drawing which shows the voltage waveform of a full wave rectification voltage and a threshold voltage regarding the lighting control apparatus same as the above. It is a schematic circuit diagram which shows the lighting control apparatus of Embodiment 4. It is a schematic circuit diagram which shows the digital power converter of a prior art example. It is a schematic circuit diagram which shows the electric power block of a digital power converter same as the above.

(Embodiment 1)
Hereinafter, the lighting control device of the present embodiment will be described with reference to FIGS.

  The lighting control device 10 of the present embodiment controls lighting of a plurality of light emitting elements 7.

  The lighting control device 10 includes a full-wave rectifying element 2 that generates a full-wave rectified voltage V1 by full-wave rectifying the sinusoidal AC voltage V0, a switching element SW1, a capacitor C2, and a primary winding L1 of the transformer T1. And a switching circuit 5 that converts the full-wave rectified voltage V1 generated by the full-wave rectifying element 2 into a predetermined DC voltage V2. In the lighting control device 10 of the present embodiment, for example, an n-channel MOSFET is used as the switching element SW1. In the present embodiment, the primary winding L1 of the transformer T1 constitutes an inductor.

  Further, the lighting control device 10 includes a resistor R3 that detects the peak current of the output current I2 that is output from the switching circuit 5 and flows through the series circuit of the plurality of light emitting elements 7 by current-voltage conversion, and the output current I2 from the switching circuit 5. And a resistor R4 for detecting the bottom current by current-voltage conversion. In the lighting control device 10 according to the present embodiment, the resistor R3 constitutes a first detection unit, and the resistor R4 constitutes a second detection unit.

  In addition, the lighting control device 10 includes a threshold value creating unit 3 that creates a threshold value Vth that increases and decreases according to an increase and decrease of the amplitude of the full wave rectified voltage V1 generated by the full wave rectifying device 2, and a control unit that controls on / off of the switching device SW1. 4 is provided.

  The full-wave rectifying element 2 can use a diode bridge constituted by four diodes D5 to D8. Here, between the input terminals 11 a and 11 b of the full-wave rectifying element 2, an AC power source 1 that is a commercial power source is electrically connected. Further, a capacitor C1 for removing a high frequency component of the full wave rectified voltage V1 generated by the full wave rectifying element 2 is connected between the output terminals 12a and 12b of the full wave rectifying element 2.

  The switching circuit 5 is formed by, for example, a step-down chopper circuit that generates a predetermined DC voltage V2 from the full-wave rectified voltage V1 generated by the full-wave rectifying element 2. This step-down chopper circuit can be composed of a switching element SW1, a diode D1, a primary winding L1 of a transformer T1, and a capacitor C2.

  The cathode side of the diode D1 is connected to the high potential side of the capacitor C1. The anode side of the diode D1 is connected to one end of the primary winding L1 of the transformer T1. A capacitor C2 is connected between the cathode side of the diode D1 and the other end of the primary winding L1 of the transformer T1.

  A series circuit of a plurality of light emitting elements 7 is connected between both ends of the capacitor C2. In the lighting control device 10 of the present embodiment, for example, an LED is used as the light emitting element 7. As the LED, for example, a phosphor (not shown) composed of an LED chip (not shown) that emits blue light and a yellow phosphor that emits broad yellow light excited by the blue light emitted from the LED chip. ) Can be used to obtain white light.

  The anode side of the diode D2 for preventing reverse current from flowing through the switching element SW1 is connected to a connection point P1 between the anode side of the diode D1 and one end of the primary winding L1 of the transformer T1. The cathode side of the diode D2 is connected to one main terminal (in this embodiment, the drain terminal) of the pair of main terminals of the switching element SW1.

  One end of the resistor R3 is connected to the other main terminal (in this embodiment, the source terminal) of the pair of main terminals of the switching element SW1.

  A resistor R4 is connected between both ends of the secondary winding L2 of the transformer T1. One end of the resistor R4 is connected to the other end of the resistor R3. A connection point P3 between one end of the resistor R4 and the other end of the resistor R3 is connected to the low potential side of the capacitor C1. Further, the connection point P3 is grounded.

  By the way, the above-described threshold value creating unit 3 is connected between both ends of the capacitor C1. The threshold value creating unit 3 is a resistance voltage dividing circuit configured by a series circuit of a resistor R1 and a resistor R2, and the voltage across the resistor R2 becomes the threshold value Vth. In short, the threshold value creating unit 3 creates a threshold value Vth by resistance-dividing the full-wave rectified voltage V1 generated by the full-wave rectifying element 2. Moreover, the threshold value creation unit 3 creates a threshold value Vth (hereinafter referred to as a threshold voltage Vth) that increases or decreases according to an increase or decrease in the amplitude of the full-wave rectified voltage V1 generated by the full-wave rectifying element 2 (see FIG. 2). In the lighting control device 10 of the present embodiment, the resistor R1 constitutes a first resistor, and the resistor R2 constitutes a second resistor.

  The control unit 4 includes a first comparator CP1, a second comparator CP2, and a logic circuit 17 that controls the switching element SW1 based on the outputs of the first comparator CP1 and the second comparator CP2. ing. In the present embodiment, the logic circuit 17 is configured by the RS flip-flop 13 and the NOT circuit 14, but the configuration is not limited thereto, and other configurations are possible as long as the switching element SW1 can be controlled at the same timing. Also good.

  The non-inverting input terminal of the first comparator CP1 is connected to a connection point P5 between the resistor R1 and the resistor R2. Therefore, the input voltage at the non-inverting input terminal of the first comparator CP1 is the threshold voltage Vth created by the threshold creation unit 3.

The inverting input terminal of the first comparator CP1 is connected to a connection point P2 between the source terminal of the switching element SW1 and the resistor R3. The output terminal of the first comparator CP1 is connected to the input terminal of the NOT circuit 14. The output terminal of the NOT circuit 14 is connected to the reset terminal R of the flip-flop 13. Note that the signal line between the output terminal of the first comparator CP1 and the input terminal of the NOT circuit 14 is pulled up to the power supply V _CC via the resistor R7. The power supply V _CC supplies the power supply voltage of the control unit 4. For example, the full-wave rectified voltage V 1 generated by the full-wave rectifying element 2 is converted into the power supply voltage of the control unit 4 to control the control unit 4. A conversion unit (not shown) for supplying to 4 is employed.

The non-inverting input terminal of the second comparator CP2 is connected to a connection point P4 between the secondary winding L2 of the transformer T1 and the other end of the resistor R4. The inverting input terminal of the second comparator CP2 is connected to a connection point P3 between the resistor R4 and the resistor R3. The output terminal of the second comparator CP2 is connected to the set terminal S of the flip-flop 13. Note that the signal line between the output terminal of the second comparator CP2 and the set terminal S of the flip-flop 13 is pulled up to the power supply V _CC via the resistor R8.

  The output terminal Q of the flip-flop 13 is connected to the control terminal (in this embodiment, a gate terminal) of the switching element SW1.

Hereinafter, the lighting control device 10 of the present embodiment will be described using specific numerical values. Here, in the present embodiment, the effective value V0 _eff of the AC voltage V0 from the AC power supply 1 is 100 [V], the frequency of the AC voltage V0 is 50 [Hz], the number of the light emitting elements 7 is 10 [pieces], and light emission. Although it is assumed that the voltage value of the forward voltage per element 7 is 3 [V] and the voltage value of the output voltage V2 of the switching circuit 5 is 30 [V], these numerical values are examples and are particularly limited. It is not a thing.

  The full-wave rectifying element 2 performs full-wave rectification on the AC voltage V0 from the AC power source 1 and applies the full-wave rectified voltage V1 across the capacitor C1. In FIG. 2, the voltage waveform of the full-wave rectified voltage V1 applied across the capacitor C1 is indicated by a solid line.

  The threshold creating unit 3 divides the full-wave rectified voltage V1 generated by the full-wave rectifying element 2 by the resistor R1 and the resistor R2, and a threshold voltage that is an input voltage of the non-inverting input terminal in the first comparator CP1. Create Vth. In FIG. 2, the voltage waveform of the threshold voltage Vth is indicated by a dotted line. As shown in FIG. 2, the voltage waveform of the threshold voltage Vth is a voltage waveform having the same cycle as that of the full-wave rectified voltage V1, that is, a voltage waveform having a cycle of 10 [ms]. The threshold voltage Vth is a value obtained by multiplying the full-wave rectified voltage V1 by a fixed ratio {R2 / (R1 + R2)}.

Here, the peak value Vth _peak of the threshold voltage Vth is obtained by the following equation when the resistance value of the resistor R1 is 1 [MΩ] and the resistance value of the resistor R2 is 300 [kΩ].

  In the lighting control device 10 of the present embodiment, when the switching element SW1 is in the ON state, the output current I2 from the switching circuit 5 is a series circuit of the plurality of light emitting elements 7, the primary winding L1 of the transformer T1, the diode D2, The current flows to the ground through the switching element SW1 and the path of the resistor R3 in order. In the present embodiment, when the switching element SW1 changes from the on state to the off state, a counter electromotive voltage is generated in the primary winding L1 of the transformer T1, and the path of the primary winding L1 and the diode D1. Thus, the output current I2 from the switching circuit 5 flows through the series circuit of the plurality of light emitting elements 7.

  By the way, in the lighting control device 10 of the present embodiment, when the switching element SW1 is in the ON state, the resistor R3 uses the peak current of the current I3 flowing through the resistor R3 (the peak current of the output current I2 from the switching circuit 5) as the current. Voltage conversion is performed to detect the first detection voltage V3.

  The first comparator CP1 compares the threshold voltage Vth, which is the input voltage of the non-inverting input terminal, with the first detection voltage V3 detected by the resistor R3.

  Here, in the lighting control device 10 of the present embodiment, assuming that the peak current of the output current I2 from the switching circuit 5 is, for example, 1 [A], the peak current of the output current I2 is converted into current and voltage. The resistance value of the resistor R3 that detects the detection voltage V3 of 1 is obtained by the following equation.

  In addition, the current I3 flowing through the resistor R3 has an inductance of the primary winding L1 of the transformer T1 of 600 [μH], an instantaneous value of the full-wave rectified voltage V1 is V1, and an instantaneous value of the output voltage V2 of the switching circuit 5 is 30 [ V], the bottom current of the output current I2 is 0 [A], and the elapsed time after the switching element SW1 is turned on is t.

  That is, the current I3 flowing through the resistor R3 increases in proportion to the elapsed time t. Further, the first detection voltage V3 detected by the resistor R3 increases as the current I3 flowing through the resistor R3 increases. In the lighting control device 10 of the present embodiment, when the first detection voltage V3 detected by the resistor R3 reaches the threshold voltage Vth, the output of the first comparator CP1 changes from the high level to the low level. Further, in the lighting control device 10 of the present embodiment, the flip-flop 13 is reset when the output of the first comparator CP1 changes from the high level to the low level. In the lighting control device 10 of the present embodiment, when the flip-flop 13 is reset, the switching element SW1 is changed from the on state to the off state.

  Further, in the lighting control device 10 of the present embodiment, when the switching element SW1 changes from the on state to the off state, a counter electromotive voltage is generated in the primary winding L1 of the transformer T1, so that the resistor R4 is connected to the transformer T1. The second detection voltage V4 is detected by current-voltage conversion of the bottom current of the output current I2 from the switching circuit 5 through the secondary winding L2. Here, the input voltage of the non-inverting input terminal of the second comparator CP2 is the second detection voltage V4.

  In the lighting control device 10 of the present embodiment, when the switching element SW1 is in the OFF state, the current IL1 flowing through the primary winding L1 of the transformer T1 is 600 [μH] in the inductance of the primary winding L1 of the transformer T1, and switching is performed. If the elapsed time since the element SW1 is turned off is t, it can be obtained by the following equation.

  That is, the current IL1 flowing through the primary winding L1 of the transformer T1 decreases in proportion to the elapsed time t. The second detection voltage V4 detected by the resistor R4 decreases as the current IL1 flowing through the primary winding L1 of the transformer T1 decreases. In the lighting control device 10 of the present embodiment, when the second detection voltage V4 detected by the resistor R4 reaches zero, the output of the second comparator CP2 changes from the low level to the high level. In the lighting control device 10 of the present embodiment, the flip-flop 13 is set when the output of the second comparator CP2 changes from low level to high level. In the lighting control device 10 of the present embodiment, when the flip-flop 13 is set, the switching element SW1 is turned on from the off state.

  The flip-flop 13 turns off the switching element SW1 when the output of the first comparator CP1 changes from the high level to the low level. The flip-flop 13 turns on the switching element SW1 when the output of the second comparator CP2 changes from low level to high level. Therefore, the control unit 4 can control on / off of the switching element SW1 at a switching frequency higher than the frequency of the AC voltage V0.

  In the lighting control device 10 of the present embodiment, the current IL1 flowing through the primary winding L1 of the transformer T1 increases as time passes after the switching element SW1 is turned on, as shown in FIG. In the present embodiment, as shown in FIG. 3, when the current IL1 reaches the threshold current Ith, the switching element SW1 is turned off and decreases with time. Further, in the present embodiment, as shown in FIG. 3, when the above-described current IL1 reaches zero, the switching element SW1 is turned on, and again increases with time. Thereby, in the lighting control device 10 of the present embodiment, it is possible to control the current IL1 flowing through the primary winding L1 of the transformer T1. In other words, the lighting control device 10 of the present embodiment can control the output current I2 from the switching circuit 5. FIG. 3 shows an enlarged current waveform of the current IL1 flowing through the primary winding L1 of the transformer T1.

  Incidentally, FIG. 4 represents an envelope connecting the peak current of the current I3 flowing through the resistor R3. In FIG. 4, a period T2 during which the switching element SW1 is turned on / off indicates a period during which the full-wave rectified voltage V1 is larger than the output voltage V2 of the switching circuit 5, and a period during which the switching element SW1 is turned off / off (T0-T2). Represents a period in which the full-wave rectified voltage V1 is equal to or lower than the output voltage V2 of the switching circuit 5.

  In the lighting control device 10 of the present embodiment, the envelope connecting the peak current of the current I3 flowing through the resistor R3 is substantially in phase with the voltage waveform (see FIG. 2) of the full-wave rectified voltage V1, as shown in FIG. Match. Here, in the lighting control device 10 of the present embodiment, the envelope connecting the peak current of the current I3 flowing through the resistor R3 has a shape that is full-wave rectified from a sinusoidal AC voltage as shown in FIG. Become. Thereby, in the lighting control device 10 of the present embodiment, the input current of the switching circuit 5 becomes a substantially sine wave whose phase substantially matches the voltage waveform of the full-wave rectified voltage V1 (input voltage of the switching circuit 5). A high power factor can be obtained.

  Further, in the lighting control device 10 of the present embodiment, since the above-described diode D2 is provided between the drain terminal of the switching element SW1 and the connection point P1, the full-wave rectified voltage V1 is equal to or lower than the output voltage V2 of the switching circuit 5. In the case of (when the on / off of the switching element SW1 is stopped), it is possible to prevent a reverse current from flowing through the switching element SW1 and to prevent the switching element SW1 from being destroyed.

  In the lighting control device 10 of the present embodiment described above, the full-wave rectifying element 2 that generates the full-wave rectified voltage V1 by full-wave rectifying the sinusoidal AC voltage V0, the switching element SW1, the capacitor C2, and the transformer T1. A switching circuit 5 that includes a primary winding (inductor) L1 and converts a full-wave rectified voltage V1 generated by the full-wave rectifier 2 into a predetermined DC voltage V2. Further, in the lighting control device 10 of the present embodiment, a resistor (first detection unit) that detects the peak current of the output current I2 that is output from the switching circuit 5 and flows through the series circuit of the plurality of light emitting elements 7 by current-voltage conversion. R3, and a resistor (second detection unit) R4 that detects the bottom current of the output current I2 from the switching circuit 5 by current-voltage conversion. Further, in the lighting control device 10 of the present embodiment, the threshold value creating unit 3 that creates the threshold value Vth that increases and decreases according to the increase and decrease of the amplitude of the full wave rectified voltage V1 generated by the full wave rectifying element 2, and the switching element SW1 is turned on and off. And a control unit 4 for controlling. Further, in the lighting control device 10 of the present embodiment, the control unit 4 turns off the switching element SW1 when the first detection voltage V3 by the resistor (first detection unit) R3 reaches the threshold value Vth, and the resistance (Second detection unit) Since the switching element SW1 is turned on when the second detection voltage V4 by the R4 reaches zero, compared to the conventional digital power converter shown in FIG. 10 and FIG. The output current can be controlled with a simple configuration, and the power factor can be improved.

Further, the lighting control apparatus 10 of the present embodiment, the output voltage V2 of the switching circuit 5 is preferably a voltage lower than the effective value V0 _eff of the AC voltage V0. Specifically, the output voltage V2 of the switching circuit 5 is preferably less than or equal to one half of the effective value _V0eff of the AC voltage V0. Thereby, in the lighting control device 10 of the present embodiment, it is possible to prevent the full-wave rectified voltage V1 generated by the full-wave rectifying element 2 from being equal to or lower than the output voltage V2 of the switching circuit 5 (ON / OFF of the switching element SW1). Therefore, it is possible to make the input current of the switching circuit 5 a sine wave whose phase coincides with the voltage waveform of the full-wave rectified voltage V1 (input voltage of the switching circuit 5). The power factor can be 0.85 or more.

In the lighting control device 10 of the present embodiment, when the effective value V0 _eff of the AC voltage V0 is 100 [V], the output voltage V2 of the switching circuit 5 is preferably 50 [V] or less. Thereby, in the lighting control device 10 of the present embodiment, when the effective value V0 _eff of the AC voltage V0 is 100 [V], the full-wave rectified voltage V1 generated by the full-wave rectifying element 2 is Since the output voltage V2 can be prevented from becoming lower (the switching element SW1 can be prevented from being turned on / off), the input current of the switching circuit 5 is changed to the voltage waveform of the full-wave rectified voltage V1 (switching circuit 5). It is possible to make a sine wave whose phase coincides with the input voltage), and to make the power factor 0.85 or more.

  Hereinafter, an example of a lighting fixture using the lighting control device 10 of the present embodiment will be described with reference to FIG.

  The lighting fixture 30 of the present embodiment includes a light source unit 6, a lighting control device 10 that controls lighting of the light source unit 6, and a fixture body 20 that holds the light source unit 6 and the lighting control device 10. For example, the lighting fixture 30 is embedded in a construction material (for example, a ceiling material) 17. In the lighting fixture 30 of the present embodiment, the light source unit 6 has a plurality of light emitting elements 7. Moreover, the instrument main body 20 is comprised so that the light source part 6 can be attached detachably.

  Although the instrument main body 20 can be comprised by metals, such as aluminum, for example, the material of the instrument main body 20 is not restricted to this, For example, materials other than a metal may be sufficient.

  Moreover, the instrument main body 20 has a main body 20a having an opening in which the light source unit 6 is accommodated and arranged, and an outer flange 20b extending outward from the opening of the main body 20a. The instrument body 20 is constructed in such a manner that the main body portion 20 a is embedded in an embedding hole 17 a penetrating the construction material 17, and the outer flange portion 20 b is in contact with the peripheral portion of the embedding hole 17 a on the lower surface of the construction material 17. It is attached to the material 17.

  On the upper side of the bottom portion 20c of the main body portion 20a, a storage portion 20d for storing the lighting control device 10 is provided, and the lighting control device 10 is arranged away from the appliance main body 20. Further, a lead-out hole (not shown) through which the electric wire 18 and the connector 18a led out from the light source unit 6 are led out into the storage unit 20d is provided in the bottom 20c of the main body 20a. Here, the connector 18a can be detachably connected to the connector 19a on the lighting control device 10 side provided at the distal end portion of the electric wire 19 electrically connected to the lighting control device 10.

  The lighting fixture 30 of the present embodiment described above includes a plurality of light emitting elements 7, a lighting control device 10 that controls the lighting of the plurality of light emitting elements 7, and the fixture body 20, so that the configuration is simpler. The output current can be controlled and the power factor can be improved.

(Embodiment 2)
The basic configuration of the lighting control device 10 of the present embodiment is the same as that of the first embodiment. As shown in FIG. 6, the amplitude of the full-wave rectified voltage V1 generated by the full-wave rectifying element 2 is larger than a specified value. In this case, the second embodiment is different from the first embodiment in that it includes a suppression unit 8 that draws a part of the current flowing through the resistor R1 corresponding to the increase in the amplitude of the full-wave rectified voltage V1 in order to suppress the fluctuation of the threshold Vth. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted suitably.

  The suppression unit 8 includes three resistors R4 to R6, a capacitor C3, and a switching element SW2 formed of an npn bipolar transistor.

  In the lighting control device 10 of the present embodiment, a resistance voltage dividing circuit configured by a series circuit of a resistor R4 and a resistor R5 is connected between both ends of the capacitor C1. A capacitor C3 is connected between a connection point P6 between the resistors R4 and R5 and the low potential side of the capacitor C1. Further, a connection point P7 between the connection point P6 and the high potential side of the capacitor C3 is connected to the base terminal of the switching element SW2. The emitter terminal of the switching element SW2 is connected to the low potential side of the capacitor C1. The collector terminal of the switching element SW2 is connected to a connection point P5 between the resistors R1 and R2 via the resistor R6.

  By the way, in the lighting control device 10 according to the first embodiment, for example, the amplitude of the full-wave rectified voltage V1 generated by the full-wave rectifying element 2 due to the fluctuation of the AC voltage V0 from the AC power supply 1 is increased by 10%. Then, the amplitude of the threshold voltage Vth increases by 10 [%], similarly to the amplitude of the full-wave rectified voltage V1.

  On the other hand, in the lighting control device 10 of the present embodiment, the full-wave rectified voltage V1 generated by the full-wave rectifying element 2 is divided by the resistors R4 and R5 between the base and the emitter of the switching element SW2. The voltage V5 smoothed by the capacitor C3 is applied. Here, the resistance value of each of the resistor R4 and the resistor R5 is a sinusoidal AC voltage V0 in which the amplitude of the full-wave rectified voltage V1 generated by the full-wave rectifying element 2 is a specified value (effective value is 100 [V]). The switching element SW2 is set to be turned on when the amplitude is larger than the amplitude of the full-wave rectified voltage V1 obtained by full-wave rectification. The resistance value of the resistor R6 is a part of the current flowing through the resistor R1 (resistor R1) corresponding to the increase in the amplitude of the full-wave rectified voltage V1 generated by the full-wave rectifier voltage 2 when the switching element SW2 is turned on. Current minus the current flowing through the resistor R2).

  In the lighting control device 10 of the present embodiment, when the amplitude of the full-wave rectified voltage V1 generated by the full-wave rectifier element 2 increases due to the increase in the amplitude of the AC voltage V0, the base current of the switching element SW2 increases. Since the switching element SW2 is turned on and a part of the current flowing through the resistor R1 corresponding to the increase in the amplitude of the full-wave rectified voltage V1 is extracted, fluctuations in the threshold voltage Vth can be suppressed. In short, the suppression unit 8 increases the amplitude of the full-wave rectified voltage V1 in order to suppress the fluctuation of the threshold value Vth when the amplitude of the full-wave rectified voltage V1 generated by the full-wave rectifying element 2 is larger than a specified value. It is possible to draw a part of the current flowing through the resistor R1 corresponding to (current flowing through the resistor R1−current flowing through the resistor R2).

  Therefore, in the lighting control device 10 of the present embodiment, when the amplitude of the full-wave rectified voltage V1 generated by the full-wave rectifying element 2 is larger than the specified value, the full-wave rectified voltage is used to suppress the fluctuation of the threshold value Vth. By having the suppression unit 8 that draws a part of the current flowing through the resistor (first resistor) R1 corresponding to the increase in the amplitude of V1, it is possible to suppress the variation in the threshold value Vth caused by the increase in the amplitude of the AC voltage V0. It becomes possible. Further, in the lighting control device 10 of the present embodiment, it is possible to suppress the fluctuation of the threshold value Vth due to the increase in the amplitude of the AC voltage V0, and therefore the peak current of the output current I2 from the switching circuit 5 fluctuates. Can be suppressed. Further, in the lighting control device 10 of the present embodiment, it is possible to suppress the fluctuation of the threshold value Vth due to the increase in the amplitude of the AC voltage V0, and therefore the output current I2 flowing through the series circuit of the plurality of light emitting elements 7 is reduced. The fluctuation can be suppressed, and the flickering of the light emitted from the light source unit 6 can be suppressed.

  In addition, you may use the lighting control apparatus 10 of this embodiment for the lighting fixture 30 demonstrated in Embodiment 1. FIG.

(Embodiment 3)
The basic configuration of the lighting control device 10 of the present embodiment is the same as that of the first embodiment. As shown in FIG. 7, the full-wave rectified voltage in the voltage waveform of the full-wave rectified voltage V1 generated by the full-wave rectifier element 2 is used. Charging including a plurality of charging capacitors C4 and C5 charged during a period when V1 is high, and charging a plurality of charging capacitors C4 and C5 during a period when the full-wave rectified voltage V1 is low in the voltage waveform of the full-wave rectified voltage V1 The point of having a valley filling circuit 9 that discharges the voltage V6 to the high potential side of the full-wave rectifying element 2 is different from the first embodiment. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted suitably.

  The valley filling circuit 9 includes two capacitors C4 and C5 and three diodes D3 to D5. In the lighting control device 10 of the present embodiment, the two capacitors C4 and C5 constitute a plurality of charging capacitors.

  In the lighting control device 10 of the present embodiment, a series circuit composed of a condenser C4 and a diode D3 is connected between the output terminals 12a and 12b of the full-wave rectifying element 2. The high potential side of the capacitor C4 is connected to one output terminal 12a of the full-wave rectifying device 2. The low potential side of the capacitor C4 is connected to the cathode side of the diode D3. The anode side of the diode D3 is connected to the other output terminal 12b of the full-wave rectifying element 2.

  Further, the lighting control device 10 of the present embodiment includes a connection point P8 between the high potential side of the capacitor C4 and the output terminal 12a of the full-wave rectifying element 2, an anode side of the diode D3, and an output terminal 12b of the full-wave rectifying element 2. A series circuit composed of a diode D4 and a capacitor C5 is connected to the connection point P9. The cathode side of the diode D4 is connected to the connection point P8. The anode side of the diode D4 is connected to the high potential side of the capacitor C5. The low potential side of the capacitor C5 is connected to the connection point P9.

  Further, the lighting control device 10 of the present embodiment includes a connection point P10 between the low potential side of the capacitor C4 and the cathode side of the diode D3, and a connection point P11 between the anode side of the diode D4 and the high potential side of the capacitor C5. A diode D5 is connected between them. The anode side of the diode D5 is connected to the connection point P10. The cathode side of the diode D5 is connected to the connection point P11.

  In the lighting control device 10 of the present embodiment, the output current I1 from the output terminal 12a of the full-wave rectifying element 2 flows to the output terminal 12b of the full-wave rectifying terminal 2 through the path of the capacitor C4, the diode D5, and the capacitor C5. . Here, in the lighting control device 10 of the present embodiment, the capacitances of the capacitor C4 and the capacitor C5 are set to be the same capacitance. In the present embodiment, each of the capacitor C4 and the capacitor C5 is charged when the full-wave rectified voltage V1 is high in the voltage waveform of the full-wave rectified voltage V1.

Hereinafter, the lighting control device 10 of the present embodiment will be described using specific numerical values. Here, in the present embodiment, the effective value V0 _eff of the AC voltage V0 from the AC power supply 1 is 100 [V], the number of the light emitting elements 7 is 20 [pieces], and the forward voltage per light emitting element 7 is Although it is assumed that the voltage value is 3 [V] and the voltage value of the output voltage V2 of the switching circuit 5 is 60 [V], these numerical values are examples and are not particularly limited.

  The voltage value of the charging voltage V6 charged in each of the capacitor C4 and the capacitor C5 is obtained by the following equation.

  Further, each of the capacitor C4 and the capacitor C5 discharges the charged charging voltage V6 to the high potential side of the full-wave rectifying element 2 when the full-wave rectified voltage V1 is low in the voltage waveform of the full-wave rectified voltage V1. To do. That is, the valley filling circuit 9 supplies the charging voltage V6 charged in the two capacitors C4 and C5 to the high potential side of the full-wave rectifying element 2 during the period when the full-wave rectified voltage V1 is low in the voltage waveform of the full-wave rectified voltage V1. Since discharging is performed, the voltage value of the valley in the voltage waveform of the full-wave rectified voltage V1 becomes approximately 71 [V], and the valley in the voltage waveform of the full-wave rectified voltage V1 can be smoothed (see FIG. 8). .

  By the way, conventionally, in the step-down chopper circuit, when the input voltage is equal to or lower than the output voltage, the on / off of the switching element is stopped.

  In response to this problem, in the lighting control device 10 of the present embodiment, the instantaneous value of the full-wave rectified voltage V1 is V1, the instantaneous value of the output voltage V2 of the switching circuit 5 is 60 [V], and the primary winding of the transformer T1. When the inductance of L1 is 600 [μH] and the elapsed time after the switching element SW1 is turned on is t, the current I3 flowing through the resistor R3 is obtained by the following equation.

  That is, in the lighting control device 10 of the present embodiment, the voltage value at the valley portion in the voltage waveform of the full-wave rectified voltage V1 is approximately 71 [V], so the current I3 flowing through the resistor R3 is always positive and the switching element SW1. It becomes possible to prevent the on / off of the power supply from stopping. In other words, in the lighting control device 10 of the present embodiment, the output current I2 flowing through the series circuit of the plurality of light emitting elements 7 is always positive, and it is possible to prevent the switching element SW1 from turning on and off. Thereby, in the lighting control device 10 of the present embodiment, even when the full-wave rectified voltage V1 is equal to or lower than the output voltage V2 of the switching circuit 5, the switching element SW1 can be turned on / off, so that a higher power factor is achieved. Can be obtained. Here, in the lighting control device 10 of the present embodiment, since the on / off of the switching element SW1 can be prevented from stopping, a reverse current flows through the switching element SW1 between the switching element SW1 and the connection point P1. There is no need to provide a diode D2 (see FIG. 1) for preventing the above. Further, in the present embodiment, since the on / off of the switching element SW1 can be prevented from being stopped, the plurality of light emitting elements 7 are turned on by a pulsating current having a frequency of, for example, 100 [Hz] or 120 [Hz]. In the case of control, the difference between the peak current and the bottom current of the output current I2 from the switching circuit 5 can be reduced, and flickering of light emitted from the light source unit 6 can be suppressed.

  Therefore, in the lighting control device 10 of the present embodiment, a plurality of capacitors (charging capacitors) that are charged in a period in which the full-wave rectified voltage V1 is high in the voltage waveform of the full-wave rectified voltage V1 generated by the full-wave rectifier element 2. The charging voltage V6 charged to the plurality of capacitors (charging capacitors) C4 and C5 during the period when the full-wave rectified voltage V1 is low in the voltage waveform of the full-wave rectified voltage V1 By having the valley filling circuit 9 that discharges to the potential side, a higher power factor can be obtained.

  In the lighting control device 10 of the present embodiment, the number of charging capacitors in the valley filling circuit 9 is two. However, the voltage at the valley in the voltage waveform of the full-wave rectified voltage V1 is the output voltage V2 of the switching circuit 5. The number of charging capacitors may be set so as to be larger than that. In the present embodiment, it is desirable to set the number of charging capacitors so that the valley voltage in the voltage waveform of the full-wave rectified voltage V1 is close to the output voltage V2 of the switching circuit 5. Thereby, in the lighting control apparatus 10 of this embodiment, it becomes possible to obtain a higher power factor.

  Moreover, you may use the lighting control apparatus 10 of this embodiment for the lighting fixture 30 demonstrated in Embodiment 1. FIG.

(Embodiment 4)
The basic configuration of the lighting control device 10 of the present embodiment is the same as that of the first embodiment, and as shown in FIG. 9, a control unit 16 having a configuration different from the control unit 4 of the first embodiment is provided. This is different from the first embodiment. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted suitably.

  The control unit 16 includes a first comparator CP 1, a second comparator CP 2, and a logic circuit 17 including a flip-flop 13 and a NOT circuit 14. The control unit 16 includes a third comparator CP3, a 2-input 1-output AND circuit 15, four resistors R7 to R10, a Zener diode ZD1, and a capacitor C6.

The output terminal of the second comparator CP2 is connected to one input terminal of the AND circuit 15. A signal line between the output terminal of the second comparator CP2 and one input terminal of the AND circuit 15 is pulled up to the power supply V _CC via the resistor R8.

  In the lighting control device 10 of the present embodiment, the series circuit of the resistor R10 and the Zener diode ZD1 is connected in parallel to the series circuit of the resistor R1 and the resistor R2 in the threshold value creating unit 3. The cathode side of the Zener diode ZD1 is connected to the resistor R10. The anode side of the Zener diode ZD1 is connected to the opposite side to the connection point P5 side of the resistor R2 with the resistor R1.

  The high potential side of the capacitor C6 is connected to the cathode side of the Zener diode ZD1. The low potential side of the capacitor C6 is connected to the anode side of the Zener diode ZD1. In the present embodiment, the Zener voltage of the Zener diode ZD1 is applied to the capacitor C6. That is, in this embodiment, the voltage across the capacitor C6 becomes the Zener voltage of the Zener diode ZD1.

  The non-inverting input terminal of the third comparator CP3 is connected to a connection point P5 between the resistor R1 and the resistor R2. Therefore, the input voltage at the non-inverting input terminal of the third comparator CP3 is the threshold voltage Vth created by the threshold creation unit 3.

  The inverting input terminal of the third comparator CP3 is connected to the high potential side of the capacitor C6. Therefore, the input voltage at the inverting input terminal of the third comparator CP3 is the voltage across the capacitor C6 (specifically, the Zener voltage of the Zener diode ZD1).

The output terminal of the third comparator CP3 is connected to the other input terminal of the AND circuit 15. Note that the signal line between the output terminal of the third comparator CP3 and the other input terminal of the AND circuit 15 is pulled up to the power source V _CC via the resistor R9.

  The third comparator CP3 compares the threshold voltage Vth, which is the input voltage of the non-inverting input terminal, with the input voltage of the inverting input terminal (specifically, the Zener voltage of the Zener diode ZD1). In the present embodiment, when the threshold voltage Vth, which is the input voltage of the non-inverting input terminal, reaches the Zener voltage of the Zener diode ZD1, the output of the third comparator CP3 changes from the low level to the high level.

  The output terminal of the AND circuit 15 is connected to the set terminal S of the flip-flop 13. In the lighting control device 10 of the present embodiment, the flip-flop 13 is set when the outputs of the second comparator CP2 and the third comparator CP3 are at a high level. In the lighting control device 10 of the present embodiment, when the flip-flop 13 is set, the switching element SW1 is turned on from the off state.

  Therefore, in the lighting control device 10 of the present embodiment, the switching element SW1 can be maintained in the off state until the threshold voltage Vth created by the threshold creating unit 3 reaches the Zener voltage of the Zener diode ZD1.

  By the way, the current I3 flowing through the resistor R3 is such that the inductance of the primary winding L1 of the transformer T1 is 600 [μH], the instantaneous value of the full-wave rectified voltage V1 is V1, and the instantaneous value of the output voltage V2 of the switching circuit 5 is 30 [ V], the bottom current of the output current I2 is 0 [A], and the elapsed time after the switching element SW1 is turned on is t.

  In the lighting control device 10 of the first embodiment, when the difference between the full-wave rectified voltage V1 and the output voltage V2 of the switching circuit 5 is small when the switching element SW1 is on, the current I3 increases in proportion to the elapsed time t. The ratio of becomes smaller.

  When the ratio of the current I3 that increases in proportion to the elapsed time t decreases in the lighting control device 10 of the first embodiment, the inventors of the present application change the current IL1 flowing through the primary winding L1 of the transformer T1 to the threshold current Ith. It has been considered that the time required to reach the switching time becomes longer, and the switching frequency for controlling on / off of the switching element SW1 becomes lower. Further, the inventors of the present application considered that, in the lighting control device 10 according to the first embodiment, when the switching frequency of the switching element SW1 is 20 [kHz] or less, the sounding is generated.

  In the lighting control device 10 of the present embodiment, the Zener voltage of the Zener diode ZD1 is set so that the switching frequency of the switching element SW1 does not become 20 [kHz] or less.

  Accordingly, in the lighting control device 10 according to the present embodiment, the switching element SW1 can be maintained in the off state until the threshold voltage Vth created by the threshold creating unit 3 reaches the Zener voltage of the Zener diode ZD1, so that the switching element It is possible to suppress the sound produced by the on / off operation of SW1.

  The lighting control device 10 of the present embodiment described above includes the control unit 16 described above, and sets the Zener voltage of the Zener diode ZD1 so that the switching frequency of the switching element SW1 does not become 20 [kHz] or less. It is. Thereby, in the lighting control device 10 of the present embodiment, it is possible to suppress the noise caused by the on / off operation of the switching element SW1.

2 Full-wave rectifier 3 Threshold creation unit 4 Control unit 5 Switching circuit 7 Light emitting element 8 Suppression unit 9 Valley filling circuit 10 Lighting control device 20 Appliance body 30 Lighting fixture C2 capacitor C4 capacitor (charging capacitor)
C5 capacitor (charging capacitor)
I2 Output current L1 Primary winding (inductor)
R1 resistance (first resistance)
R2 resistance (second resistance)
R3 resistance (first detection unit)
R4 resistance (second detection unit)
SW1 Switching element V0 AC voltage V1 Full-wave rectified voltage V2 Output voltage (DC voltage)
V3 First detection voltage V4 Second detection voltage V6 Charging voltage Vth threshold

Claims (8)

  A full-wave rectifying element that generates a full-wave rectified voltage by full-wave rectifying a sinusoidal AC voltage, and includes a switching element, a capacitor, and an inductor. The full-wave rectified voltage generated by the full-wave rectifying element is a predetermined direct current. A switching circuit for converting to a voltage; a first detector for detecting a peak current of an output current output from the switching circuit and flowing in a series circuit of a plurality of light emitting elements by current-voltage conversion; and the output from the switching circuit A second detector for detecting a bottom current of the current by converting the current to a voltage; a threshold creating unit for creating a threshold that increases or decreases according to an increase or decrease in the amplitude of the full-wave rectified voltage generated by the full-wave rectifier; A control unit that controls on / off of a switching element, and the control unit, when the detection voltage by the first detection unit reaches the threshold value, Off the switching element, when the voltage detected by the second detection unit has reached zero, the lighting control device, characterized in that on the switching element.   The threshold value creating unit is a resistance voltage dividing circuit configured by a series circuit of a first resistor and a second resistor, and the threshold value is obtained by resistance-dividing the full-wave rectified voltage generated by the full-wave rectifying element. And when the amplitude of the full-wave rectified voltage is larger than a specified value, the current flowing through the first resistor corresponding to the increase in the vibration of the full-wave rectified voltage to suppress the fluctuation of the threshold The lighting control device according to claim 1, further comprising a suppression unit that pulls out a part thereof.   In the voltage waveform of the full-wave rectified voltage generated in the full-wave rectified voltage, the full-wave rectified voltage includes a plurality of charging capacitors that are charged in a high period. 2. The lighting control device according to claim 1, further comprising a valley filling circuit that discharges charging voltages charged in the plurality of charging capacitors to a high potential side of the full-wave rectifying element during a period in which the rectified voltage is low.   4. The lighting control device according to claim 1, wherein an output voltage of the switching circuit is a voltage lower than an effective value of the AC voltage. 5.   4. The lighting control device according to claim 1, wherein an output voltage of the switching circuit is equal to or less than a half of an effective value of the AC voltage. 5.   4. The lighting control device according to claim 1, wherein an output voltage of the switching circuit is 50 V or less when an effective value of the AC voltage is 100 V. 5.   The lighting control device according to any one of claims 1 to 6, wherein a switching frequency of the switching element does not include 20 kHz or less.   The illumination comprising: the plurality of light emitting elements; and the lighting control device according to any one of claims 1 to 7 that controls lighting of the plurality of light emitting elements. Instruments.

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