JP2014130697A - Light-emitting element lighting device and luminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting element lighting device and a luminaire capable of shortening a time required for start when the light-emitting element is dimmed by performing phase control allowing for the conduction angle of a power supply voltage to vary.SOLUTION: A dimming control unit 3 performs phase control by controlling a phase angle at which a triac Q81 turns on, a phase detection circuit 1c generates a duty signal at a duty ratio corresponding to the conduction angle of an AC voltage, and a dimming circuit 1d includes a first capacitor capable of being switched between charge and discharge according to the level of the duty signal, with which it generates a target signal. A first control power supply circuit PS1 generates a first control voltage for causing a power conversion circuit 1b to operate, by using a phase-controlled AC voltage when the power conversion circuit 1b operates, and a second control power supply circuit PS2 causes the power conversion circuit 1b to operate in a rise period, and generates a second control voltage for charging the first capacitor in at least the rise period, by using phase-controlled AC voltage.

Description

  The present invention relates to a light emitting element lighting device and a lighting fixture.

  Conventionally, as shown in FIG. 13, there is a light emitting element lighting device in which a lighting fixture 101 is connected between both ends of a commercial power source 100 and a dimming circuit 102 dims the lighting fixture 101.

  The dimming circuit 102 receives a binary PWM dimming signal generated at a duty ratio corresponding to the dimming level from the outside. The dimming circuit 102 includes an RC charging / discharging circuit (not shown) using a resistor and a capacitor. The RC charging / discharging circuit charges and discharges the capacitor according to the value of the PWM dimming signal. And the dimming circuit 102 dimmes the lighting fixture 101 to the dimming level according to the DC voltage value which generate | occur | produces between the both ends of a capacitor | condenser by RC charge / discharge circuit.

  As a conventional light emitting element lighting device, there is a light emitting element lighting device in which a series circuit of a lighting fixture 111 and a dimmer 112 is connected between both ends of a commercial power supply 100 as shown in FIG. Reference 1).

  The luminaire 111 includes a light source unit 111a such as an LED (Light Emitting Diode) element or an organic EL (Electroluminescence) element, and a dimming circuit 111b for dimming the light source unit 111a. The dimmer 112 includes a triac Q112 that is a bidirectional switching element having a self-holding function, and a dimming control unit 112a that controls the triac Q112.

  The triac Q112 is connected in series between the commercial power supply 100 and the lighting fixture 111. The dimming control unit 112a controls the phase angle at which the triac Q112 is turned on, and performs phase control that makes the conduction angle of the power supply voltage of the commercial power supply 100 variable.

  The dimming circuit 111b of the luminaire 111 performs full-wave rectification on the phase-controlled power supply voltage, and generates a binary signal (duty signal) set to a duty ratio according to the conduction angle of the power supply voltage. The dimming circuit unit 111b includes an RC charging / discharging circuit (not shown) using a resistor and a capacitor. The RC charging / discharging circuit charges and discharges the capacitor according to the value of the duty signal. Then, the dimming circuit 111b dims the light source unit 111a to a dimming level corresponding to a DC voltage value generated between both ends of the capacitor by the RC charge / discharge circuit.

JP 2012-185998 A

  First, in the conventional light emitting element lighting device shown in FIG. 13, the PWM frequency of the PWM dimming signal is relatively high, around 1 kHz to several tens of kHz, and the capacitance of the capacitor used in the RC charge / discharge circuit of the dimming circuit unit 102 is Can be relatively small.

  On the other hand, when dimming by phase control that makes the conduction angle of the power source voltage of the commercial power source 100 variable as in the conventional light emitting element lighting device shown in FIG.

  The frequency of the duty signal generated by the dimming circuit 111b is 100 Hz / 120 Hz, which is twice the commercial frequency 50 Hz / 60 Hz of the commercial power supply 100, and is lower than the PWM frequency described above. Therefore, a capacitor used for the RC charge / discharge circuit of the dimming circuit 111b needs to have a relatively large capacity of about several μF to several tens of μF. In this case, the time required for charging the capacitor becomes longer during the rising period of the light emitting element lighting device.

  Thus, the conventional light emitting element lighting device shown in FIG. 14 takes a long time to start. In particular, when the dimming level is low and the conduction angle of the power supply voltage is short, the charging current to the capacitor of the RC charging / discharging circuit is low, so that the start delay is noticeable.

  The present invention has been made in view of the above-described reasons, and the object thereof is to shorten the time required for starting when the light emitting element is dimmed by performing phase control that makes the conduction angle of the power supply voltage variable. A light-emitting element lighting device and a lighting fixture are provided.

  The light-emitting element lighting device of the present invention has an electric power supplied from an AC power supply as an input, a power conversion circuit that supplies lighting power to a light source unit configured by the light-emitting elements, and a series of the power conversion circuit and the AC power supply. A bidirectional switching element connected in series with the circuit and having a self-holding function, and a phase control for varying the conduction angle of the AC voltage of the AC power supply by controlling the phase angle at which the bidirectional switching element is turned on. A light control unit; a phase detection circuit that generates a binary duty signal set to a duty ratio corresponding to a conduction angle of the AC voltage; and a first that switches between charging and discharging according to the value of the duty signal A dimming circuit including a capacitor and generating a target signal in which a target value of a load current flowing through the light source unit is set according to the voltage of the first capacitor; and the load current An output feedback circuit that compares the target signal and adjusts the lighting power supplied by the power conversion circuit; and a normal operation period after a predetermined time has elapsed since the start of power supply from the AC power supply. A first control power supply circuit that generates a first control voltage for operating the power conversion circuit; and the power in a rising period from when the power supply from the AC power supply is started until the predetermined time elapses. A second control power supply circuit that starts an operation of the conversion circuit and generates a second control voltage for charging the first capacitor at least during the rising period using an input voltage of the power conversion circuit; It is characterized by providing.

  In the present invention, a second capacitor connected between the output terminals of the power conversion circuit, a third control power supply circuit for generating a third control voltage from the voltage of the second capacitor, and the first capacitor When the power conversion circuit is switched from the operation state to the stop state, the first switching element is preferably turned on by the third control voltage. .

  In the present invention, the power conversion circuit includes a transformer having a primary winding, a secondary winding, and a tertiary winding, and a second switching element that conducts and interrupts a current supplied from the AC power source to the primary winding. The lighting power is supplied from the secondary winding by causing the second switching element to conduct / cut off the current supplied to the primary winding, and the first control power supply circuit includes: The first control voltage higher than the second control voltage by using a voltage induced in the tertiary winding by the second switching element conducting / cutting off the current supplied to the primary winding. And the first capacitor is charged by the second control voltage until the first control voltage exceeds the second control voltage, and the first control voltage is the second control voltage. After exceeding the voltage It is preferably charged by said first control voltage.

  In this invention, until the first control voltage exceeds the second control voltage, the second control voltage is converted into a predetermined voltage to charge the first capacitor, and the first control voltage It is preferable to provide a fourth control power circuit that converts the first control voltage into the predetermined voltage and charges the first capacitor after the voltage exceeds the second control voltage.

  In the present invention, the dimming control unit continuously supplies a trigger signal for turning on the bidirectional switching element for a predetermined period of the period in which the bidirectional switching element is conductive, It is preferable that the dimming curve indicating the relationship with the load current changes along a curve in which the slope for decreasing the load current decreases as the conduction angle decreases.

  In the present invention, the output feedback circuit includes a series circuit of a third switching element and a resistance element connected in series to the light source unit, and when the load current increases relative to the target signal, When the switching element is controlled in a direction in which the resistance between both ends of the third switching element increases and the load current decreases relative to the target signal, the resistance between the both ends of the third switching element is reduced. By controlling the switching element in a direction in which resistance decreases, a ripple component of the output voltage of the power conversion circuit is applied across the switching element, and the third switching element and the resistance element are connected in series. Preferably, the load current is controlled at a constant current by monitoring the voltage across the circuit.

  In the present invention, the light emitting element is preferably an LED element or an organic EL element.

  The lighting apparatus of the present invention is connected in series to an AC power supply and a bidirectional switching element having a self-holding function, and a conduction angle of the AC voltage of the AC power supply is controlled by controlling a phase angle at which the bidirectional switching element is turned on. And a power conversion circuit that supplies lighting power to the light source unit by using power supplied from the AC power source as an input. And a phase detection circuit that generates a binary duty signal set to a duty ratio corresponding to the conduction angle of the AC voltage, and a first capacitor that can be switched between charging and discharging according to the value of the duty signal. A dimming circuit that generates a target signal in which a target value of a load current flowing through the light source unit is set according to the voltage of the first capacitor, the load current, and the target An output feedback circuit for adjusting the lighting power supplied by the power conversion circuit, and the power in a steady operation period after a predetermined time has elapsed since the start of power supply from the AC power supply. A first control power supply circuit for generating a first control voltage for operating the conversion circuit; and the power conversion circuit in a rising period from when power supply from the AC power supply is started until the predetermined time elapses And a second control power supply circuit that generates a second control voltage for charging the first capacitor at least during the rising period by using an input voltage of the power conversion circuit. It is characterized by that.

  As described above, in the present invention, when the light emitting element is dimmed by performing phase control that makes the conduction angle of the power supply voltage variable, the charging current by the second control circuit charges the capacitor of the dimming circuit. Therefore, there is an effect that the time required for starting can be shortened.

It is a block diagram which shows the structure of the light emitting element lighting device of Embodiment 1. It is a block diagram which shows the structure of a lighting fixture same as the above. It is a circuit diagram which shows a part of structure of a lighting fixture same as the above. It is a circuit diagram which shows a part of structure of a lighting fixture same as the above. It is a circuit diagram which shows a part of structure of a lighting fixture same as the above. It is a circuit diagram which shows a part of structure of a lighting fixture same as the above. It is a circuit diagram which shows a part of structure of a lighting fixture same as the above. (A)-(d) It is a wave form diagram which shows operation | movement of each part same as the above. It is a wave form diagram which shows operation | movement of a phase detection circuit same as the above. (A)-(d) It is a wave form diagram of each part explaining a bypass current same as the above. It is a characteristic view which shows the light control curve same as the above. It is a circuit diagram which shows a part of structure of the lighting fixture of Embodiment 2. FIG. It is a block diagram which shows the structure of the conventional light emitting element lighting device. It is a block diagram which shows the structure of another conventional light emitting element lighting device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a configuration of a light emitting element lighting device of the present embodiment. The light emitting element lighting device is configured by connecting a series circuit of a lighting fixture 1 and a dimmer 2 between both ends of a commercial power source 10 (AC power source). The dimmer 2 adjusts the power supplied from the commercial power supply 10 to the lighting fixture 1 by phase-controlling the power supply voltage (AC voltage) of the commercial power supply 10.

  As shown in FIG. 2, the luminaire 1 includes an input filter circuit 1a, a power conversion circuit 1b, a phase detection circuit 1c, a dimming circuit 1d, an output feedback circuit 1e, a bleeder circuit 1f, and a light source unit 1h. With.

  The input filter circuit 1a includes a capacitor, an inductor, and the like, and has a function of suppressing noise propagating to the power supply line and noise radiating to the space.

  As shown in FIG. 3, the power conversion circuit 1b includes a rectifier circuit DB1, capacitors C1 and C2, a transformer T1, a switching element Q1 (second switching element), a control circuit K1, and a diode D1. Thus, a non-insulated flyback converter is configured. The power conversion circuit 1b constitutes a quasi-resonant circuit for reducing loss and noise, and further has a power factor improving function for improving the power factor of the commercial power source 10.

  First, the rectifier circuit DB1 is configured by full-bridge connection of diodes, and full-wave rectifies the power supply voltage of the commercial power supply 10.

  The capacitor C1 is a film capacitor connected between the output terminals of the rectifier circuit DB1, and suppresses a voltage / current spike generated when the switching element Q1 is turned on. The capacitor C1 has a smaller capacity than the smoothing capacitor and does not take into account the smoothing action. That is, the power conversion circuit 1b does not include a smoothing capacitor having a large capacity such as an electrolytic capacitor in the input means, and does not constitute a capacitor input type power supply circuit.

  The transformer T1 includes a primary winding N1, a secondary winding N2, and a tertiary winding N3, and the windings are magnetically coupled to each other. A series circuit of the primary winding N1 and the switching element Q1 is connected between the output ends of the rectifier circuit DB1, and a diode D1 is interposed at one end of the secondary winding N2, and the secondary winding A smoothing capacitor C2 (second capacitor) is connected in parallel to the series circuit of N2 and the diode D1.

  The control circuit K1 conducts / cuts off the current flowing from the commercial power supply 10 to the primary winding N1 by driving the switching element Q1 on and off. When the switching element Q1 is on, a current flows through the series circuit of the primary winding N1 and the switching element Q1, and magnetic energy is accumulated in the primary winding N1. Next, when the switching element Q1 is turned off, an induced voltage is generated in the secondary winding N2 due to the magnetic energy of the primary winding N1, and a voltage is generated across the capacitor C2.

  The control circuit K1 performs switching control of the switching element Q1, thereby controlling the output of the power conversion circuit 1b to a predetermined value and further improving the power factor of the commercial power supply 10. Note that the power factor correction operation by the flyback converter is a well-known technique and will not be described in detail.

  The light source unit 1h includes a plurality of LED elements and organic EL elements connected in series or in parallel, and is connected between both ends of the capacitor C2.

  The phase detection circuit 1c is connected to the cathodes of the diodes Da and Db whose anodes are connected to the respective input terminals of the rectifier circuit DB1, and is a voltage Vd (full-wave rectified from the power supply voltage phase-controlled by the dimmer 2). A full-wave rectified voltage Vd) is input. Then, the phase detection circuit 1c detects the conduction angle of the power supply voltage input to the lighting fixture 1 (conduction angle of the full-wave rectified voltage Vd), and is a binary value set to a duty ratio corresponding to the detected conduction angle. The signal (duty signal S1) is output to the dimming circuit 1d.

  The dimming circuit 1d sets a target value of the load current corresponding to the duty ratio of the duty signal S1, and outputs a voltage signal (target signal S2) corresponding to the target value of the load current to the output feedback circuit 1e.

  The output feedback circuit 1e detects a load current flowing through the light source unit 1h by a resistor or the like connected in series with the light source unit 1h. The output feedback circuit 1e acquires the target value of the load current based on the target signal S2 input from the dimming circuit 1d. Then, the output feedback circuit 1d outputs a feedback signal S3 (for example, an error between the detected value of the load current and the target value) to the control circuit K1 based on the detected value of the load current and the target value. Constant current control is performed to match the target value (see FIG. 3).

  The control circuit K1 performs constant current control so that the load current matches the target value by setting the conduction period (ON period) of the switching element Q1 according to the feedback signal S3.

  FIG. 4 shows a specific circuit configuration of the output feedback circuit 1e. The output feedback circuit 1e includes a series circuit of a FET element Q91 and a resistor R91 connected in series to the light source unit 1h, the drain of the FET element Q91 is connected to the light source unit 1h, and the source of the FET Q91 is connected to the resistor R91. . The output of the operational amplifier OP91 is connected to the gate of the FET element Q91 and further connected to a later-described fourth control voltage Vcc4 via the resistor R93. Furthermore, a resistor R92 is connected between the inverting input and output of the operational amplifier OP91, and the inverting input of the operational amplifier OP91 is connected to the source of the FET element Q91. The non-inverting input of the operational amplifier OP91 is connected to the low-voltage side output of the power conversion circuit 1b via the capacitor C91, and the target signal S2 is further input via the resistor R94.

  The inverting input of the operational amplifier OP92 is connected to the drain of the FET element Q91 via the resistor R95, and the non-inverting input of the operational amplifier OP92 divides a fourth control voltage Vcc4 described later by a series circuit of resistors R96 and R97. The pressed voltage is input. Further, a resistor R98 is connected between the inverting input and the output of the operational amplifier OP92.

  When the light source unit 1h is composed of an LED element or an organic EL element, a large ripple occurs in the load current flowing through the light source unit 1h due to the ripple of the output voltage of the power conversion circuit 1b (the voltage across the capacitor C2), and flicker and flickering occur. Cause.

  Therefore, by configuring the output feedback circuit 1e as shown in FIG. 4, the output voltage of the operational amplifier OP91 decreases when the load current increases relative to the target value (target signal S2), and reaches the target value. On the other hand, it increases when the load current decreases relatively. That is, the operational amplifier OP91 controls the FET element Q91 in the direction in which the drain-source resistance of the FET element Q91 increases when the load current increases relative to the target value. Further, the operational amplifier OP91 controls the FET element Q91 in the direction in which the drain-source resistance of the FET element Q91 decreases when the load current decreases relative to the target value.

  In this configuration, since the ripple of the output voltage of the power conversion circuit 1b is applied between the drain and source of the FET element Q91, a substantially constant voltage with reduced ripple is applied to the voltage across the light source unit 1h. The

  Further, the operational amplifier OP92 has a function of controlling the power supplied to the light source unit 1h, and the drain voltage of the FET element Q91 (the voltage across the series circuit of the FET element Q91 and the resistor R91) becomes the target voltage. Thus, the feedback signal S3 is output to the control circuit K1. That is, the operational amplifier OP91 monitors the voltage across the series circuit of the FET element Q91 and the resistor R91, and outputs the feedback signal S3 to the control circuit K1, thereby controlling the constant current so that the load current matches the target value. I do.

  Next, as shown in FIG. 1, the dimmer 2 includes a capacitor C81 and an inductor L81 that form a noise prevention filter, and a triac Q81 that is a bidirectional switching element having a self-holding function. The capacitor C81 is connected between the input ends of the dimmer 2, and a series circuit of a triac Q81 and an inductor L81 is connected in parallel to the capacitor C81. Then, when the triac Q81 is in a conducting state, AC power is supplied from the commercial power supply 10 to the power conversion circuit 1b.

  The dimmer 2 includes a power supply unit 4. The power source unit 4 generates a control power source for operating each unit (a dimming control unit 3 described later) of the dimmer 2 and is connected in parallel to the triac Q81.

  The power supply unit 4 includes a diode D81, a capacitor C82, a power supply circuit K81, and a capacitor C83.

  The diode D81 is connected to the power supply line from the lighting fixture 1, and the capacitor C82 is connected in parallel to the triac Q81 via the diode D81. The power supply circuit K81 converts the voltage across the capacitor C82 into a control voltage Vs and outputs it. The capacitor C83 is a smoothing capacitor connected between the output terminals of the power supply circuit K81. Here, the low voltage terminal of the capacitor C83 is connected to the circuit ground.

  Furthermore, the dimmer 2 includes a dimming control unit 3. The dimming control unit 3 includes a synchronization signal generation unit K82, a control circuit K83, and an operation unit K84, and performs phase control to change the conduction angle of the power supply voltage of the commercial power supply 10 by turning on the triac Q81. Do.

  First, the synchronization signal generation unit K82 is connected to the power supply line (the anode side of the diode D81) from the luminaire 1 via the diode D82. The synchronization signal generation unit K82 has a ground terminal connected to the circuit ground, generates a synchronization signal shown in FIG. 8A based on the phase of the power supply voltage supplied from the commercial power supply 10, and supplies the synchronization signal to the control circuit K83. Output. Specifically, the synchronization signal generation unit K82 compares the power supply voltage of the commercial power supply 10 with a predetermined threshold Vt1 by detecting the power supply voltage of the commercial power supply 10 via the diode D82, and the power supply voltage sets the threshold Vt1. A synchronization signal is generated with the period exceeding the H level. That is, the synchronization signal rises when the power supply voltage exceeds the threshold value Vt1, and falls when the power supply voltage falls below the threshold value Vt1. 8A to 8C, the broken line indicates the waveform of the power supply voltage of the commercial power supply 10.

  The control circuit K83 generates a trigger signal for turning on the triac Q81 based on the synchronization signal provided from the synchronization signal generation unit K82 and the dimming signal provided from the operation unit K84 (see FIG. 8B). The rise and fall of the trigger signal are both determined with reference to the rise of the synchronization signal. The control circuit K83 outputs a trigger signal to the gate of the triac Q81, whereby a drive current flows through the gate of the triac Q81 and the triac Q81 becomes conductive. Here, the control circuit K83 employs a so-called DC trigger method in which a trigger signal for turning on the triac Q81 is continuously supplied for a predetermined period of time during which the triac Q81 is turned on to be conducted.

  That is, the dimming control unit 3 controls the phase of the power supply voltage applied to the lighting fixture 1 by turning on the triac Q81 using the DC trigger method.

  Hereinafter, the dimming operation of the present embodiment will be described. First, the synchronization signal generation unit K82 generates a synchronization signal and outputs it to the control circuit K83. In addition, the operation unit K84 outputs a dimming signal corresponding to the user operation to the control circuit K83. The control circuit K83 generates a trigger signal based on the synchronization signal and the dimming signal, and outputs it to the gate of the triac Q81. The triac Q81 is turned on when the trigger signal rises and becomes conductive. Therefore, as shown in FIG. 8C, the power supply voltage of the commercial power supply 10 is phase-controlled and applied to the lighting fixture 1. The rising edge of the trigger signal changes in phase angle depending on the voltage signal output from the operation unit K84 operated by the user. Thereby, since the conduction angle of the power supply voltage applied to the lighting fixture 1 changes, light control can be performed.

  Thereafter, when the trigger signal falls, the driving current does not flow to the gate of the triac Q81. Since the triac Q81 maintains a conductive state while the anode current exceeds the holding current, the power supply voltage of the commercial power supply 10 is continuously applied to the lighting fixture 1 for a while after the trigger signal falls (FIG. 8 (c). )reference). When the anode current of the triac Q81 becomes equal to or lower than the holding current, the triac Q81 is switched to a non-conduction state (off state). Thereby, application of the power supply voltage of the commercial power supply 10 to the lighting fixture 1 stops.

  In the lighting fixture 1, the phase detection circuit 1c detects the conduction angle of the power supply voltage input to the lighting fixture 1, and outputs a duty signal S1 corresponding to the detected conduction angle to the dimming circuit 1d. The dimming circuit 1d sets a target value of the load current according to the duty ratio of the duty signal S1, and outputs a target signal S2 corresponding to the target value. The output feedback circuit 1e outputs a feedback signal S3 based on the detected value of the load current and the target value to the control circuit K1. The control circuit K1 sets the conduction period (ON period) of the switching element Q1 according to the feedback signal S3, thereby performing constant current control so that the load current matches the target value, and dimming the light source unit 1h. To do.

  Here, as shown in FIG. 8B, unlike the pulse trigger, the trigger signal is continuously at the H level for a certain period of time during which the lighting fixture 1 is supplied with power for lighting. As a result, the drive current continues to flow through the gate of the triac Q81 until the trigger signal falls. That is, the drive current is continuously applied to the triac Q81 for a certain period (the H level period of the trigger signal) of the period in which the triac Q81 is turned on.

  Moreover, the lighting fixture 1 uses the power conversion circuit 1b which has a power factor improvement function, and as shown in FIG.8 (d), the input current of the lighting fixture 1 becomes a sine wave shape, and the power factor of the commercial power source 10 is the same. It has been improved. That is, the anode current of the triac Q81 can be secured even when the amplitude of the power supply voltage of the commercial power supply 10 decreases past the peak and reaches the vicinity of the zero cross. Therefore, even when noise is superimposed on the power supply line of the commercial power supply 10 near the zero cross of the power supply voltage of the commercial power supply 10, fluctuations in the conduction period of the triac Q81 can be suppressed, and the lighting of the light source unit 1h may be flickering or unexpected. The possibility of turning off the light can be reduced.

  Thus, the light emitting element lighting device of the present embodiment performs stable dimming without unexpectedly turning off the triac Q81 even if noise is superimposed on the power supply line of the commercial power supply 10 near the zero cross of the power supply voltage. It can be carried out.

  Furthermore, in this embodiment, a bleeder circuit 1f is provided in parallel on the input side of the power conversion circuit 1b so that a sufficient anode current exceeding the holding current continuously flows in the triac Q81 even in the off period of the trigger signal. (See FIG. 2). The bleeder circuit 1f also has a function of supplying power to the power supply unit 4 of the dimmer 2 when the triac Q81 is turned off.

  First, as shown in FIG. 5, the bleeder circuit 1f includes diodes Da and Db each having an anode connected to each input terminal of the rectifier circuit DB1, cathodes of the diodes Da and Db, and a low voltage side of the rectified output of the rectifier circuit DB1. And a current drawing portion 1g connected between the two. That is, the bleeder circuit 1 f can be considered equivalent to a bleeder circuit 1 f connected in parallel between the input ends of the lighting fixture 1.

  In the current drawing unit 1g shown in FIG. 5, a series circuit of an FET element Q71, a resistor R71, and a resistor R72 is connected between the cathodes of the diodes Da and Db and the low-voltage side of the rectified output of the rectifier circuit DB1. The drain of the FET element Q71 is connected to the cathodes of the diodes Da and Db, and the source of the FET element Q71 is connected to a series circuit of resistors R71 and R72. Furthermore, the gate of the FET element Q71 is connected to the phase detection circuit 1c. A Zener diode ZD71 is connected between the gate of the FET element Q71 and the low-voltage side of the rectified output of the rectifier circuit DB1.

  The phase detection circuit 1 c detects the conduction angle of the power supply voltage input to the lighting fixture 1. Specifically, the full-wave rectified voltage Vd (see FIG. 9A) obtained by full-wave rectifying the power supply voltage is input to the phase detection circuit 1c via the diodes Da and Db. The full-wave rectified voltage Vd Is compared with the threshold value Vt2 to generate a binary duty signal S1 set to a duty ratio corresponding to the conduction angle. The duty signal S1 is at the L level when the amplitude of the power supply voltage is greater than or equal to the threshold Vt2, and is at the H level when the amplitude of the power supply voltage is less than the threshold Vt2 (see FIG. 9B). The phase detection circuit 1c applies this duty signal S1 to the gate of the FET element Q71 of the current drawing unit 1g.

  The FET element Q71 is turned on when the duty signal S1 is at H level, that is, when the amplitude of the full-wave rectified voltage Vd is less than the threshold value Vt2, via the diode Da or Db, the FET element Q71, and the resistors R71 and R72. A bypass current Ib flows. The bypass current Ib flows through a closed circuit including the commercial power supply 10, the bleeder circuit 1 f, and the dimmer 2 using the commercial power supply 10 as a supply source.

  Hereinafter, the operation of the bleeder circuit 1f will be described with reference to FIGS. In the following description, reference numerals of the bypass currents Ib1 and Ib2 are given depending on the generation period of the bypass current Ib. In FIGS. 10A and 10B, the broken line indicates the waveform of the power supply voltage of the commercial power supply 10.

  First, when the power supply voltage passes through the zero cross, the amplitude of the full-wave rectified voltage Vd is less than the threshold value Vt2 (see FIG. 10B), and the duty signal S1 becomes H level (see FIG. 10C). ), The FET element Q71 is turned on, and the bypass current Ib1 is generated (see FIG. 10D). At this time, the triac Q81 of the dimmer 2 is off, and the bypass current Ib1 charges the capacitor C82 via the diode D81 of the dimmer 2. That is, the power supply unit 4 generates the control voltage Vs using the bypass current Ib1, and can secure the control power supply with a simple configuration.

  Then, when the trigger signal rises (see FIG. 10A) and the triac Q81 becomes conductive, the power supply voltage of the commercial power supply 10 is applied to the lighting fixture 1. When the full-wave rectified voltage Vd becomes equal to or higher than the threshold value Vt2 (see FIG. 10B), the duty signal S1 becomes L level (see FIG. 10C), the FET element Q71 is turned off, and the bypass current Ib1 becomes zero (see FIG. 10D).

  Then, when the amplitude of the power supply voltage increases to the peak value and then decreases and the trigger signal falls (see FIG. 10A), the drive current does not flow to the gate of the triac Q81, but the triac Q81 As long as the current exceeds the holding current, the conduction state is maintained.

  In this embodiment, when the full-wave rectified voltage Vd is less than the threshold value Vt2 (see FIG. 10B), the duty signal S1 becomes H level (see FIG. 10C), and the FET element Q71. Is turned on, and a bypass current Ib2 is generated (see FIG. 10D). The bypass current Ib2 flows through the triac Q81 that maintains the conductive state after the trigger signal falls, so that the anode current is maintained at or above the holding current.

  Therefore, even if noise is superimposed on the power supply line of the commercial power supply 10 near the zero cross of the power supply voltage, stable dimming can be performed without the triac Q81 turning off unexpectedly.

  In the embodiment shown in FIG. 10, by setting the threshold value Vt2 to be relatively high, the duty signal S1 is switched to the H level and the bypass current Ib2 starts to flow before the trigger signal falls, so that noise resistance is improved. Is further improved.

  Note that after the trigger signal falls, the duty signal S1 may be switched to the H level and the bypass current Ib2 may start to flow. In this case, the circuit loss can be further reduced by shortening the period during which the bypass current Ib2 flows.

  Furthermore, in the present embodiment, by using the power conversion circuit 1b having the power factor improvement function, the required bypass current Ib can be suppressed and the circuit loss can be reduced as compared with the case where the capacitor input type power conversion circuit is used. You can plan.

  Further, the power factor improvement by the power conversion circuit 1b eliminates the need for the bypass current Ib to flow in the phase angle region where the load current is high (the region where the power supply voltage is high), thereby further reducing the circuit loss. Can do.

  In addition, the current drawing unit 1g includes the FET element Q71 so that the sum of the gate-source voltage of the FET element Q71 and the voltage across the series circuit of the resistors R71 and R72 matches the Zener voltage of the Zener diode ZD71. The drain current is constant current controlled. That is, the bypass current Ib is controlled at a constant current by the current drawing unit 1g, and the bypass current Ib does not greatly exceed a necessary holding current, and contributes to a reduction in circuit loss.

  The dimming circuit 1d and the current drawing unit 1g operate using the duty signal S1 generated by the phase detection circuit 1c. That is, the lighting fixture 1 can simplify a structure and can reduce parts by using the common duty signal S1 for the dimming circuit 1d and the current drawing unit 1g.

  Next, the luminaire 1 includes first to fourth control power supply circuits PS1 to PS4 in order to supply a control voltage to each unit.

  As shown in FIG. 3, the first control power supply circuit PS1 includes a series circuit of a tertiary winding N3 of a transformer T1 and a diode D2. A capacitor Ca is connected in parallel to the series circuit of the tertiary winding N3 and the diode D2. The voltage Vcc across the capacitor Ca becomes the first control voltage Vcc1 by the power supplied from the tertiary winding N3. Further, a discharging resistor Ra is connected between both ends of the capacitor Ca.

  Specifically, when the power conversion circuit 1b is in operation and the switching element Q1 is on, magnetic energy is accumulated in the primary winding N1, and then when the switching element Q1 is turned off, the magnetism of the primary winding N1 Due to the energy, an induced voltage is generated in the tertiary winding N3. Due to this induced voltage, the capacitor Ca is charged via the diode D2, and the first control voltage Vcc1 is generated across the capacitor Ca. That is, the voltage Vcc across the capacitor Ca becomes the first control voltage Vcc1 by the power supplied from the first control power supply circuit PS1.

  As shown in FIG. 6, the second control power supply circuit PS2 includes a resistor R21, a Zener diode ZD21, a transistor Q21, a capacitor C21, and a diode D21. The full-wave rectified voltage Vd is applied to the series circuit of the resistor R21 and the Zener diode ZD21. The base of the transistor Q21 is connected to the midpoint of connection between the resistor R21 and the Zener diode ZD21, and the full-wave rectified voltage Vd is applied to the collector of the transistor Q21. Further, the emitter of the transistor Q21 is connected to the low voltage side of the rectified output of the rectifier circuit DB1 via the capacitor C21, and further connected to the positive electrode of the capacitor Ca via the diode D21.

  In the second control power supply circuit PS2, the sum of the base-emitter voltage of the transistor Q21 and the voltage across the capacitor C21 matches the Zener voltage of the Zener diode ZD21. The voltage across the capacitor C21 is controlled at a constant voltage, and charges the capacitor Ca via the diode D21. That is, the voltage Vcc across the capacitor Ca becomes the second control voltage Vcc2 by the power supplied from the second control power supply circuit PS2. The second control voltage Vcc2 is lower than the first control voltage Vcc1.

  As shown in FIG. 3, the third control power supply circuit PS3 includes resistors R11 and R12, a Zener diode ZD11, a transistor Q11, and a capacitor C11. A series circuit of the resistor R11 and the Zener diode ZD11 is connected in parallel to the secondary-side capacitor C2 of the power conversion circuit 1b. The base of the transistor Q11 is connected to the midpoint of connection between the resistor R11 and the Zener diode ZD11, and the collector of the transistor Q11 is connected to the positive electrode of the capacitor C2. Further, the emitter of the transistor Q11 is connected to the negative electrode of the capacitor C2 via the capacitor C11, and the resistor R12 is connected in parallel to the capacitor C11.

  In the third control power supply circuit PS3, the sum of the base-emitter voltage of the transistor Q11 and the voltage across the capacitor C11 matches the Zener voltage of the Zener diode ZD11. The voltage across the capacitor C11 is constant voltage controlled and becomes the third control voltage Vcc3. That is, the third control power supply circuit PS3 converts the voltage across the capacitor C2 into the third control voltage Vcc3 and outputs it.

  As shown in FIG. 6, the fourth control power supply circuit PS4 includes capacitors C31 and C32 and a three-terminal regulator REG31. A capacitor C31 is connected in parallel to the input side of the three-terminal regulator REG31, and a capacitor C32 is connected in parallel to the output side of the three-terminal regulator REG31. A voltage Vcc across the capacitor Ca is applied to the capacitor C31, and a voltage controlled to a constant voltage is generated in the capacitor C32. The voltage across the capacitor C32 becomes the fourth control voltage Vcc4. That is, the fourth control power supply circuit PS4 converts the voltage Vcc across the capacitor Ca into the fourth control voltage Vcc4 and outputs it.

  Here, the first control voltage Vcc1> the second control voltage Vcc2> the fourth control voltage Vcc4> the third control voltage Vcc3 is set. For example, the first control voltage Vcc1 = 24V, the second control voltage Vcc2 = 18.6V, the fourth control voltage Vcc4 = 7V, and the third control voltage Vcc3 = 4.5V.

  Next, the operations by the control voltages Vcc1 to Vcc4 generated by the first to fourth control power supply circuits PS1 to PS4 are (1) a rising period of the light emitting element lighting device, (2) a steady operation period of the light emitting element lighting device, (3) Each case when the light emitting element lighting device is stopped will be described.

(1) Rise period of light-emitting element lighting device (period from when power supply from commercial power supply 10 is started to when first control voltage Vcc1 exceeds second control voltage Vcc2)
First, when power supply from the commercial power supply 10 to the lighting fixture 1 and the dimmer 2 is started, the second control power supply circuit PS2 is supplied with the full-wave rectified voltage Vd via the diodes Da and Db, 2 control voltage Vcc2. At this time, the switching element Q1 of the power conversion circuit 1b is in an off state, and the first control power supply circuit PS1 does not generate the first control voltage Vcc1. Thus, the voltage Vcc across the capacitor Ca becomes the second control voltage Vcc2.

  The second control voltage Vcc2 generated at both ends of the capacitor Ca serves as a control power source for the phase detection circuit 1c via the diode Dc.

  As shown in FIG. 7, the phase detection circuit 1c includes a series circuit of a resistor R41 to which a full-wave rectified voltage Vd is applied, a Zener diode ZD41, and a resistor R42, and a capacitor C42 is connected in parallel to the resistor R42. Further, the gate of the transistor Q41 is connected to the midpoint of connection between the Zener diode ZD41 and the resistor R42. The collector of the transistor Q41 is connected to the voltage Vcc across the capacitor Ca (Vcc = Vcc2 in the rising period) via the resistor R43 and the diode Dc, and the emitter of the transistor Q41 is connected to circuit ground. A resistor R44 is connected between the collector and emitter of the transistor Q41. Then, the collector voltage of the transistor Q41 becomes the duty signal S1.

  In the phase detection circuit 1c, when the full-wave rectified voltage Vd is less than the threshold value Vt2 (see FIG. 9), the transistor Q41 is turned off, the collector voltage of the transistor Q41 becomes the second control voltage Vcc2, and the duty signal S1 Becomes H level. When the full-wave rectified voltage Vd is equal to or higher than the threshold value Vt2 (see FIG. 9), the transistor Q41 is turned on, the collector voltage of the transistor Q41 becomes substantially 0V, and the duty signal S1 becomes L level.

  That is, the phase detection circuit 1c generates the duty signal S1 using the second control voltage Vcc2 generated by the second control power supply circuit PS2 during the rising period. The bleeder circuit 1f, to which the duty signal S1 is input, causes the bypass current Ib to flow. The power supply unit 4 of the dimmer 2 generates a control voltage Vs using the bypass current Ib and controls the triac Q81 to start phase control that makes the conduction angle of the power supply voltage of the commercial power supply 10 variable.

  The bleeder circuit 1f originally has a function of causing the triac Q81 to stably operate with the bypass current Ib. And by making this bleeder circuit 1f share the function of generating the control power source of the dimmer 2 during the rising period, the control power source of the dimmer 2 during the rising period can be generated with a simple configuration.

  Further, the second control voltage Vcc2 is input to the fourth control power supply circuit PS4, and the fourth control power supply circuit PS4 generates the fourth control voltage Vcc4 and supplies it to the dimming circuit 1d.

  The light control circuit 1d has the circuit configuration shown in FIG. First, the FET element Q51 (first switching element) is provided in the input stage, and the duty signal S1 is input to the gate of the FET element Q51. The fourth control voltage Vcc4 is applied to the drain of the FET element Q51 via the resistor R51. Furthermore, a series circuit of resistors R52 and R53 is connected between the drain and source of the FET element Q51, and a capacitor C51 (first capacitor) is connected in parallel to the resistor R53. This FET element Q51, resistors R51, R52, R53, and capacitor C51 constitute a first stage RC charge / discharge circuit.

  The dimming circuit 1d also includes an FET element Q52 (first switching element) in the input stage, and the duty signal S1 is input to the gate of the FET element Q52. The voltage across the capacitor C51 is applied to the drain of the FET element Q52 via the resistor R54. Further, a series circuit of resistors R55 and R56 is connected between the drain and source of the FET element Q52, and a capacitor C52 (first capacitor) is connected in parallel to the resistor R56. The FET element Q52, resistors R54, R55, R56, and capacitor C52 constitute a second stage RC charge / discharge circuit. Note that the fourth control voltage is also supplied to the power supplies of the operational amplifiers OP51 and OP52.

  Then, as the conduction angle of the power supply voltage decreases and the on-duty ratio of the duty signal S1 increases (as the dimming level decreases), the voltage across the capacitors C51 and C52 decreases. The change in the voltage across the capacitor C52 with respect to the conduction angle of the power supply voltage becomes a curve represented by a second-order polynomial by the first-stage and second-stage RC charge / discharge circuits described above. In FIG. 7, the RC charge / discharge circuit has a two-stage configuration, but by increasing the number of stages of the RC charge / discharge circuit, the change in the voltage across the capacitor C52 with respect to the conduction angle of the power supply voltage is higher order polynomial. It is represented by

  Next, the voltage between both ends of the capacitor C52 is amplified by an amplifier circuit including an operational amplifier OP51 and resistors R57 to R60. In the operational amplifier OP51, the voltage across the capacitor C52 is connected to the non-inverting input via the resistor R57. Further, in the operational amplifier OP51, a resistor R59 is connected between the inverting input and the circuit ground, and a resistor R58 is connected between the inverting input and the output. That is, the operational amplifier OP51 functions as a non-inverting amplifier, and outputs an amplified signal obtained by amplifying the voltage across the capacitor C52 through the resistor R60. The upper limit of the output voltage of the operational amplifier OP51 is limited by the Zener diode ZD51 provided to the output of the operational amplifier OP51 via the resistor R60. That is, the dimming upper limit is determined by setting the upper limit of the output voltage of the operational amplifier OP51 using the Zener diode ZD51.

  Next, the output voltage of the operational amplifier OP51 is input to a subtraction circuit composed of an operational amplifier OP52 and resistors R61 to R66. The output voltage of the operational amplifier OP51 is divided by a series circuit of resistors R61 and R62 and connected to the non-inverting input of the operational amplifier OP52. The fourth control voltage Vcc4 is applied between both ends of the series circuit of the resistors R63 and R64, and the connection midpoint of the resistors R63 and R64 is connected to the inverting input of the operational amplifier OP52 via the resistor R65. Further, a resistor R66 is connected between the inverting input and the output of the operational amplifier OP52. The lower limit of the output voltage of the operational amplifier OP52 is limited by the operational amplifier OP52 functioning as a subtracting circuit. That is, the light control lower limit is determined by setting the lower limit of the output voltage of the operational amplifier OP52.

  The output of the operational amplifier OP52 is divided by a series circuit of resistors R67 and R68, and the voltage at the connection midpoint of the resistors R67 and R68 becomes the target signal S2.

  Here, the frequency of the duty signal S1 is 100 Hz / 120 Hz, which is twice the commercial frequency 50 Hz / 60 Hz of the commercial power supply 10. Therefore, the capacitors C51 and C52 used in the RC charging / discharging circuit of the dimming circuit 1d are required to have a relatively large capacity of about several μF to several tens of μF.

  However, in the present embodiment, as described above, the capacitor C51 of the first stage RC charge / discharge circuit and the capacitor C52 of the second stage RC charge / discharge circuit are generated from the second control voltage Vcc2 during the rising period. It is charged by the fourth control voltage Vcc4. That is, the second control voltage Vcc2 is converted to the fourth control voltage Vcc4 by the fourth control power supply circuit PS4, and is also used for charging the capacitors C51 and C52 during the rising period. Therefore, in the rising period, the time until the target signal S2 is generated can be shortened, and the time required for starting can be shortened. In particular, even when the dimming level is low and the conduction angle of the power supply voltage is short, the time required for charging the capacitors C51 and C52 can be shortened, which is effective.

  The fourth control voltage Vcc4 is also supplied to the output feedback circuit 1e via the diode Df, and the output feedback circuit 1e uses the fourth control voltage Vcc4 to output the feedback signal S3 corresponding to the target signal S2. Output.

  The voltage Vcc across the capacitor Ca (Vcc = Vcc2 in the rising period) serves as an operation power supply for the control circuit K1, and the control circuit K1 starts to turn on / off the switching element Q1. When the switching element Q1 starts a switching operation, an induced voltage is generated in the tertiary winding N3, and the first control power supply circuit PS1 generates the first control voltage Vcc1. When the switching element Q1 starts a switching operation, an induced voltage is generated in the secondary winding N2, and the third control power supply circuit PS3 generates the third control voltage Vcc3.

  That is, in the rising period, the second control power supply circuit PS2 generates the second control voltage Vcc2 before the first control power supply circuit PS1 generates the first control voltage Vcc1. Therefore, charging of the capacitor Ca during the rising period of the light emitting element lighting device uses the second control voltage Vcc2 of the second control power supply circuit PS2 (Vcc = Vcc2). When the switching operation of the power conversion circuit 1b is started and the first control voltage Vcc1 exceeds the second control voltage Vcc2, the capacitor Ca is charged by the first control voltage Vcc1 (Vcc = Vcc1). Therefore, in the rising period, the charging time of the capacitor Ca can be shortened, and the time required for starting can be shortened.

  Further, the phase detection circuit 1c generates the duty signal S1 from the second control voltage Vcc2 supplied during the rising period, and this configuration can also shorten the time required for starting.

  Further, the dimming circuit 1d is operated by the duty signal S1 generated from the second control voltage Vcc2 supplied during the rising period, and this configuration can also shorten the time required for starting.

(2) Steady operation period of light-emitting element lighting device (period after power supply from commercial power supply 10 is started and first control voltage Vcc1 exceeds second control voltage Vcc2)
The lighting fixture 1 in the steady operation period is operated by the first control voltage Vcc1 generated by the first control power supply circuit PS1. The timing at which the rising period is switched to the steady operation period (the timing at which the first control voltage Vcc1 exceeds the second control voltage Vcc2) may be before or after the light source unit 1h is turned on.

  The first control voltage Vcc1 is generated at a higher voltage value than the second control voltage Vcc2. Therefore, when the switching element Q1 starts the switching operation and the first control voltage Vcc1 exceeds the second control voltage Vcc2, the charging of the capacitor Ca by the second control power supply circuit PS2 is stopped, and the first control power supply The capacitor Ca is charged by the circuit PS1. Thus, the voltage Vcc of the capacitor Ca is Vcc = Vcc1.

  Then, the fourth control power supply circuit PS4 generates the fourth control voltage Vcc4 using the first control voltage Vcc1 supplied via the diode Dc, and the phase detection circuit 1c receives the first control voltage Vcc1. A duty signal S1 is generated using Vcc1. The first control voltage Vcc1 serves as an operation power supply for the control circuit K1, and the control circuit K1 continues to turn on / off the switching element Q1.

  Thus, during the steady operation of the light-emitting element lighting device, the lighting fixture 1 uses the first control voltage Vcc1 higher than the second control voltage Vcc2 as the control power supply. Since the input / output voltage difference (input voltage-output voltage) of the first control power supply circuit PS1 is smaller than the input / output voltage difference of the second control power supply circuit PS2, the first control voltage Vcc1 is used as the control power supply. As a result, the loss at the time of generating the control voltage can be reduced.

  The operations of the other parts are the same as (1) the operation during the rising period of the light-emitting element lighting device, and a description thereof will be omitted.

(3) When the light emitting element lighting device is stopped (when power supply from the commercial power supply 10 is cut off)
When power supply from the commercial power source 10 to the lighting fixture 1 and the dimmer 2 is interrupted, the capacitor Ca is discharged by the resistor Ra, and the control voltage Vcc is instantaneously reduced. Therefore, the discharge time of the control voltage Vcc is short. Further, since the full-wave rectified voltage Vd becomes zero, the transistor Q41 of the phase detection circuit 1c is turned off.

  On the other hand, the third control power supply circuit PS3 generates the third control voltage Vcc3 by the residual charge of the capacitor C2 on the secondary side of the power conversion circuit 1b. The third control voltage Vcc3 is applied to the gates of the FET elements Q51 and Q52 of the dimming circuit 1d via the diode Dd, and the FET elements Q51 and Q52 are turned on. Therefore, the electric charge of the capacitor C51 of the dimming circuit 1d is discharged through the resistor R52 and the FET element Q51. Furthermore, the electric charge of the capacitor C52 of the dimming circuit 1d is discharged through the resistor R55 and the FET element Q52.

  Thus, after the power supply is cut off, the electric charges of the capacitors C51 and C52 are discharged within a short time. Therefore, even when the time interval from turn-off to restart is short, the residual charge of the capacitors C51 and C52 is small, so that the dimming level at the time of restart becomes higher than necessary, and the light output is temporarily reduced. The phenomenon of starting light jumping out is suppressed.

  Note that the charge of the capacitor C51 is also discharged through the resistor R53, and the charge of the capacitor C52 is discharged through the resistor R56. However, since the resistance value of the resistor R53 is larger than the resistance value of the resistor R52, and the resistance value of the resistor R56 is larger than the resistance value of the resistor R55, each discharge amount through the resistors R53 and R56 is a resistance value. It is smaller than each discharge amount via R52 and R55. That is, the generation of the discharge path through the FET elements Q51 and Q52 when the light emitting element lighting device is stopped is an effective configuration for shortening the discharge time of the capacitors C51 and C52. The greater the number of stages of the charge / discharge circuit, the more effective.

  Further, the third control voltage Vcc3 is also supplied to the output feedback circuit 1e via the diode De.

  As described above, the light emitting element lighting device is started, operated, and stopped by the control voltages Vcc1 to Vcc4 generated by the first to fourth control power supply circuits PS1 to PS4.

  Next, FIG. 11 is a dimming curve showing the dimming characteristics of the dimming circuit 1d, and shows the relationship between the conduction angle of the power supply voltage and the load current. In FIG. 11, the load current corresponds to the phase angle α (see FIG. 10) when the trigger signal rises.

  In the region of the phase angle α1 to α2 of the dimming curve, the load current decreases in a curved shape as the phase angle α increases, and this curve is represented by a quadratic polynomial. That is, as the phase angle α increases (as the conduction angle decreases), the slope at which the dimming curve decreases decreases. Therefore, instead of using linear dimming control, the light output changes suddenly in areas where the dimming level is high, and in areas where the dimming level is low, flickering caused by noise cannot be recognized by human eyes. By reducing the change in light output, natural dimming characteristics are realized. In particular, when the dimming level is low (when the phase angle is small), fine dimming control is possible, and the natural dimming change is suppressed by suppressing the discomfort of the human eye against the change in dimming level. Can be realized.

  In FIG. 11, in the region where the phase angle is α1 or more and the phase angle α2 or less, the load current changes along a curve represented by a quadratic polynomial. This curve shows the sensitivity of the human eye. It may be a curve represented by a LOG scale adapted to the above or a curve showing characteristics close to this. If the flicker due to noise is allowed in a region where the light control level is low, the light control characteristic of the region having the phase angle α1 or more and the phase angle α2 or less may be represented by a straight line.

  Further, the dimming circuit 1d sets the upper limit of the output voltage of the operational amplifier OP51 by using the Zener diode ZD51, thereby setting the upper limit of the load current in the region of phase angle 0 ° to α1 (region where the conduction angle is large). The constant maximum value Imax is set.

  Furthermore, the dimming circuit 1d sets the lower limit of the output current of the operational amplifier OP52, thereby setting the lower limit of the load current to a certain minimum value Imin in the region of the phase angle α2 to 180 ° (region where the conduction angle is small). doing.

  In the dimming method of the lighting fixture 1 of the present embodiment, the light source unit 1h is dimmed by turning on and off the switching element Q1, but a circuit that performs dimming by varying the current flowing through the light source unit 1h. It goes without saying that the same effect can be achieved with the configuration.

  The LED element and the organic EL element used for the light source unit 1h are different from the conventional discharge lamp, and particularly require startability and restartability, and shorten the time required for start-up and restart as described above. The configuration is an effective means.

  Moreover, in this embodiment, although the LED element or the organic EL element is used as the light source part 1h, it does not need to be limited to this and you may use another solid light emitting element for the light source part 1h.

(Embodiment 2)
FIG. 12 shows another form in which the capacitors C51 and C52 of the dimming circuit 1d are charged and discharged during the rise period and stop of the light emitting element lighting device.

  First, the second control voltage Vcc2 generated by the second control power supply circuit PS2 is connected to the positive electrodes of the capacitors C51 and C52 via the switch SW1. Further, the positive electrodes of the capacitors C51 and C52 are connected to the circuit ground via the switch SW2. The switch control circuit K90 controls the on / off operation of the switches SW1 and SW2. The switch control circuit K90 is composed of a microcomputer or the like, and monitors the second control voltage Vcc2 and the voltage at the connection point between the cathodes of the diodes Dc and Dd (control power supply for the phase detection circuit 1c). The switch control circuit K90 uses the control voltage Vcc as an operating power supply.

  First, in an initial state where commercial power is not supplied to the light emitting element lighting device, both the switches SW1 and SW2 are turned off.

  In the rising period, the control voltage Vcc (the second control voltage Vcc2 at this time) is supplied via the diode Dc as the control power supply for the phase detection circuit 1c. When the switch control circuit K90 detects the rise of the second control voltage Vcc2, the switch control circuit K90 turns on the switch SW1 to charge the capacitors C51 and C52 with the second control voltage Vcc2. Therefore, in the rising period, not only the fourth control voltage Vcc4 but also the second control voltage Vcc2 is used together to charge the capacitors C51 and C52, so that the starting time can be further shortened.

  When the control voltage Vcc is switched from the second control voltage Vcc2 to the first control voltage Vcc1, the switch control circuit K90 turns off the switch SW1 after the control voltage Vcc exceeds the second control voltage Vcc2, and the switch Both SW1 and SW2 are turned off (during steady operation of the light emitting element lighting device).

  Next, at the time of stop, the control voltage Vcc is lowered, and the third control voltage Vcc3 (Vcc3 <Vcc2 <Vcc1) is supplied via the diode Dd as the control power supply for the phase detection circuit 1c. When the control power supply of the phase detection circuit 1c drops from the first control voltage Vcc1 to the third control voltage Vcc3, the switch control circuit K90 turns on the switch SW2 and discharges the capacitors C51 and C52. Therefore, at the time of stop, not only the FET elements Q51 and Q52 but also the switch SW2 is used together to discharge the capacitors C51 and C52, so that the discharge time of the capacitors C51 and C52 at the time of stop can be further shortened.

  Other configurations are the same as those in the first embodiment, and a description thereof will be omitted.

DESCRIPTION OF SYMBOLS 1 Lighting fixture 2 Dimmer 3 Dimming control part 10 Commercial power supply (AC power supply)
DESCRIPTION OF SYMBOLS 1b Power conversion circuit 1c Phase detection circuit 1d Dimming circuit 1e Output feedback circuit 1h Light source part PS1 1st control power supply circuit PS2 2nd control power supply circuit Q81 Triac (bidirectional switching element)

Claims (8)

A power conversion circuit that supplies power supplied from an AC power source as input and supplies lighting power to a light source unit composed of light emitting elements;
A bidirectional switching element connected in series to a series circuit of the power conversion circuit and the AC power supply and having a self-holding function;
A dimming control unit that performs phase control to vary the conduction angle of the AC voltage of the AC power supply by controlling the phase angle at which the bidirectional switching element is turned on;
A phase detection circuit that generates a binary duty signal set to a duty ratio according to the conduction angle of the AC voltage;
A target signal including a first capacitor that can be switched between charging and discharging according to the value of the duty signal, and setting a target value of the load current flowing through the light source unit according to the voltage of the first capacitor. A dimming circuit for generating
An output feedback circuit for comparing the load current and the target signal and adjusting the lighting power supplied by the power conversion circuit;
A first control power supply circuit that generates a first control voltage for operating the power conversion circuit in a steady operation period after a predetermined time has elapsed since the start of power supply from the AC power supply;
First operation for starting the operation of the power conversion circuit in the rising period from when the power supply from the AC power supply is started until the predetermined time elapses, and charging the first capacitor at least in the rising period And a second control power supply circuit that generates the control voltage of 2 using the input voltage of the power conversion circuit. A second capacitor connected between the output terminals of the power conversion circuit;
A third control power circuit for generating a third control voltage from the voltage of the second capacitor;
A first switching element that forms a discharge path of the first capacitor,
The light-emitting element lighting device according to claim 1, wherein when the power conversion circuit is switched from an operating state to a stopped state, the first switching element is turned on by the third control voltage. The power conversion circuit includes a transformer having a primary winding, a secondary winding, and a tertiary winding, and a second switching element that conducts and cuts off a current supplied from the AC power source to the primary winding, The second switching element conducts and cuts off the current supplied to the primary winding, thereby supplying the lighting power from the secondary winding,
The first control power supply circuit uses the voltage induced in the tertiary winding by the second switching element to conduct / cut off the current supplied to the primary winding, and the second control power circuit Generating the first control voltage higher than the voltage;
The first capacitor is charged by the second control voltage until the first control voltage exceeds the second control voltage, and the first control voltage exceeds the second control voltage. After that, the light emitting element lighting device according to claim 1, wherein the light emitting element lighting device is charged by the first control voltage.   The second control voltage is converted into a predetermined voltage to charge the first capacitor until the first control voltage exceeds the second control voltage, and the first control voltage is the second control voltage. 4. The light emitting device according to claim 3, further comprising: a fourth control power circuit that converts the first control voltage into the predetermined voltage and charges the first capacitor after the control voltage exceeds the control voltage. Element lighting device. The dimming control unit continuously supplies a trigger signal for turning on the bidirectional switching element for a predetermined period of time during which the bidirectional switching element is conducted,
The dimming curve indicating the relationship between the conduction angle of the AC voltage and the load current changes along a curve in which the slope that decreases the load current decreases as the conduction angle decreases. The light emitting element lighting device according to any one of 1 to 4.   The output feedback circuit includes a series circuit of a third switching element and a resistance element connected in series to the light source unit, and when the load current increases relative to the target signal, When the switching element is controlled in a direction in which the resistance between both ends of the switching element increases and the load current decreases relative to the target signal, the resistance between the both ends of the third switching element decreases. By controlling the switching element in the direction, the ripple component of the output voltage of the power conversion circuit is applied across the switching element, and the voltage across the series circuit of the third switching element and the resistance element is applied. The light emitting element lighting device according to claim 1, wherein the load current is controlled by constant current monitoring.   The light-emitting element lighting device according to claim 1, wherein the light-emitting element is an LED element or an organic EL element. By phase control that is connected in series to an AC power source and a bidirectional switching element having a self-holding function, and that controls the phase angle at which the bidirectional switching element is turned on, thereby making the conduction angle of the AC voltage of the AC power source variable. A dimmable lighting fixture,
A light source unit composed of light emitting elements;
A power conversion circuit for supplying lighting power to the light source unit with power supplied from the AC power supply as an input;
A phase detection circuit that generates a binary duty signal set to a duty ratio according to the conduction angle of the AC voltage;
A target signal including a first capacitor that can be switched between charging and discharging according to the value of the duty signal, and setting a target value of the load current flowing through the light source unit according to the voltage of the first capacitor. A dimming circuit for generating
An output feedback circuit for comparing the load current and the target signal and adjusting the lighting power supplied by the power conversion circuit;
A first control power supply circuit that generates a first control voltage for operating the power conversion circuit in a steady operation period after a predetermined time has elapsed since the start of power supply from the AC power supply;
First operation for starting the operation of the power conversion circuit in the rising period from when the power supply from the AC power supply is started until the predetermined time elapses, and charging the first capacitor at least in the rising period And a second control power supply circuit that generates the control voltage of 2 using the input voltage of the power conversion circuit.

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