JP5611174B2 - Power supply device and lighting device - Google Patents

Description

  The present invention relates to a power supply device that supplies power to a load circuit such as a light source circuit.

2. Description of the Related Art A two-stage power supply device including a power factor correction circuit and a power conversion circuit is known.
The power factor correction circuit is a circuit that improves the power factor of the input of the power supply device, and for example, a boost converter circuit or the like is used.
The power conversion circuit is a circuit for adjusting the power output from the power supply device, and performs, for example, a constant current driving operation that keeps the current flowing through the load circuit constant. As the power conversion circuit, for example, a buck converter circuit, a flyback converter circuit, other DC / DC conversion circuits (DC / DC converter circuits), and the like are used.

JP-A-9-55296 JP 2010-40400 A

For example, in a lighting device in which a load circuit is a light source circuit having a light source such as a light emitting diode (hereinafter referred to as “LED”) or organic electroluminescence (hereinafter referred to as “organic EL”), the brightness of the light source is adjusted. When the power supplied from the power supply device to the load circuit is varied over a wide range, such as when the power supply device has a dimming function, the power factor correction circuit reduces the power supplied from the power supply device to the load circuit. In some cases, the power factor improvement effect due to the power supply is reduced, and the power factor of the power supply device is reduced.
Moreover, in order to save energy, it is necessary to suppress power loss in the power supply device as much as possible.
Further, when a boost type circuit is used as the power factor correction circuit, the operation of the power factor correction circuit may become unstable if the target value of the output of the power factor correction circuit is rapidly changed.
The present invention has been made to solve the above-described problems, for example, and prevents a decrease in power factor even when the power supplied to the load circuit is small, such as during dimming, and reduces power loss in the power supply device. The purpose is to stabilize the operation of the power factor correction circuit while suppressing it.

A power supply apparatus according to the present invention is a DC power supply apparatus that inputs an AC voltage and outputs a DC current of a predetermined current value,
The range of the voltage peak value of the AC voltage is a first voltage that is not less than a minimum value and not more than a maximum value of the voltage peak value range of the AC voltage, a second voltage higher than the first voltage, and the first voltage. A third voltage lower than one voltage,
The DC power supply device includes a power factor correction circuit and a control circuit,
The power factor correction circuit receives an AC voltage within the range of the voltage peak value as input, converts the input AC voltage into a DC voltage, outputs the converted DC voltage, and inputs the converted DC voltage to the power factor improvement circuit. Increase the power factor of the alternating current
The control circuit controls the voltage target value of the DC voltage output from the power factor correction circuit, and the higher the voltage value of the AC voltage input to the power factor correction circuit, the higher the voltage target value, When the voltage peak value of the AC voltage is not less than the minimum value of the voltage peak value range of the AC voltage input to the power factor correction circuit and not more than the third voltage, and not less than the first voltage and not less than the second voltage. The voltage peak value of the AC voltage is not less than the minimum value in the range of the voltage peak value of the AC voltage input to the power factor correction circuit and not more than the third voltage and the first voltage. The rate of change of the voltage target value with respect to the change of the voltage value of the AC voltage is made smaller than in the case where the voltage is within another voltage range different from the second voltage or less.

  According to the power supply device of the present invention, when the voltage value of the AC voltage input to the power factor correction circuit changes within a predetermined voltage range, the change rate of the target value is small, thereby preventing the power factor from being lowered. The stability of the power factor correction circuit can be enhanced while suppressing power loss in the power supply device.

FIG. 3 is a schematic diagram illustrating an example of an overall configuration of a lighting device 800 according to Embodiment 1. FIG. 2 is a circuit diagram illustrating an example of a detailed configuration of the power supply circuit 100 and the like in Embodiment 1. FIG. 6 is a characteristic diagram illustrating an example of characteristics of the power factor correction circuit 110 according to the first embodiment. FIG. 6 is a characteristic diagram illustrating an example of characteristics of the power factor correction circuit 110 according to the first embodiment. The characteristic view which shows an example of the characteristic of the power factor improvement circuit in a comparative example. FIG. 10 is a characteristic diagram illustrating an example of characteristics of the power factor correction circuit 110 according to the second embodiment. FIG. 10 is a characteristic diagram illustrating an example of characteristics of the power factor correction circuit 110 according to the third embodiment. FIG. 10 is a characteristic diagram illustrating an example of characteristics of the power factor correction circuit 110 according to the fourth embodiment. FIG. 10 is a characteristic diagram illustrating an example of characteristics of the power factor correction circuit 110 according to the fifth embodiment. The figure which shows the relationship between the nominal voltage of a commercial power source, and the number of the country or area which uses the commercial power source. FIG. 20 is a characteristic diagram illustrating an example of characteristics of the power factor correction circuit 110 according to the sixth embodiment. FIG. 18 is a characteristic diagram illustrating an example of characteristics of the power factor correction circuit 110 according to the seventh embodiment. FIG. 20 is a flowchart showing an example of a flow of set voltage calculation processing S610 in the seventh embodiment. FIG. 20 is a characteristic diagram illustrating an example of characteristics of the power factor correction circuit 110 according to the eighth embodiment. FIG. 20 is a timing chart illustrating an example of operation of the power supply circuit 100 according to Embodiment 8. FIG. 20 is a timing chart illustrating another example of the operation of the power supply circuit 100 according to the eighth embodiment.

Embodiment 1 FIG.
The first embodiment will be described with reference to FIGS.

  FIG. 1 is a schematic diagram showing an example of the overall configuration of lighting apparatus 800 in this embodiment.

  The lighting device 800 is supplied with AC power from an AC power source AC such as a commercial power source and lights a light source such as an LED or an organic EL. The AC voltage input to the lighting device 800 has a frequency of 50 Hz to 60 Hz and a voltage effective value of 85 V to 265 V, for example. In addition, a dimming signal output from the dimmer 820 is input to the lighting device 800. The dimming signal (supplied power instruction signal) is a signal for instructing the dimming degree for turning on the light source of the lighting device 800. The dimming signal is, for example, a pulse wave-modulated rectangular wave signal, and the pulse width represents the dimming degree. The lighting device 800 turns on the light source according to the dimming degree indicated by the dimming signal. The illumination device 800 includes, for example, a power supply circuit 100 (power supply device) and a light source circuit 810 (load circuit).

  The light source circuit 810 includes a light source (light emitting element) that is turned on by a direct current. The light source circuit 810 receives the direct current output from the power supply circuit 100 and turns on the light source by the input direct current.

  The power supply circuit 100 receives an AC voltage supplied from the AC power supply AC, converts the input AC voltage into a DC current supplied to the light source circuit 810, and outputs the converted DC current. The power supply circuit 100 includes, for example, a power factor correction circuit 110, a power conversion circuit 130, a control circuit 140, and a dimming signal input circuit 180.

The power factor correction circuit 110 converts an AC voltage supplied from the AC power supply AC into a DC voltage, and outputs the converted DC voltage. The power factor correction circuit 110 adjusts the voltage value (generated voltage) of the DC voltage to be converted in accordance with an instruction from the control circuit 140 and increases the power factor of the input of the power supply circuit 100 to approach 1.
The control circuit 140 (generated voltage setting circuit) is configured such that the power factor correction circuit 110 is based on the voltage value of the alternating voltage input to the power factor correction circuit 110, the current value of the direct current output from the power factor correction circuit 110, and the like. The voltage target value of the DC voltage to be converted is determined, and the power factor correction circuit 110 is controlled so that the voltage value of the DC voltage generated by the power factor correction circuit 110 matches the determined voltage target value.
The power conversion circuit 130 receives the DC voltage output from the power factor correction circuit 110, steps down the input DC voltage, converts it to a DC voltage having a different voltage value, and converts the converted DC voltage to the output voltage of the power supply circuit 100. Output as. In accordance with an instruction from the dimming signal input circuit 180, the power conversion circuit 130 adjusts so that the current value of the direct current output from the power conversion circuit 130 matches the current target value.
The dimming signal input circuit 180 (dimming circuit) receives the dimming signal output from the dimmer 820 and flows it to the light source of the light source circuit 810 to turn on the light source at the dimming degree indicated by the input dimming signal. A target value of the power current is determined, and a signal representing the determined current target value is output. As the dimming degree is higher, the current value of the direct current flowing through the light source circuit 810 increases, and the luminous flux of light emitted from the light source of the light source circuit 810 increases. The signal output from the dimming signal input circuit 180 is input to the power conversion circuit 130, and the current value of the DC current to be converted is matched with the current target value represented by the input signal.
As a result, the power supply circuit 100 drives the light source circuit 810 with a constant current.

The control circuit 140 receives the signal output from the dimming signal input circuit 180 instead of the current value of the direct current output from the power factor correction circuit 110, and based on the current target value represented by the input signal, The configuration may be such that the voltage target value of the DC voltage to be converted by the power factor correction circuit 110 is determined. This is because if the current target value is large, the current value of the direct current output from the power factor correction circuit 110 is large, and if the current target value is small, the current value of the direct current output from the power factor correction circuit 110 is small. .
Alternatively, the control circuit 140 inputs the dimming signal output from the dimmer 820 instead of the current value of the direct current output from the power factor correction circuit 110, and based on the dimming degree represented by the input signal, The configuration may be such that the voltage target value of the DC voltage to be converted by the rate improvement circuit 110 is determined. If the dimming degree is high, the current target value increases, and the current value of the direct current output from the power factor correction circuit 110 increases. This is because if the dimming degree is low, the current target value becomes small, and the current value of the direct current output from the power factor correction circuit 110 becomes small.

  FIG. 2 is a circuit diagram showing an example of a detailed configuration of the power supply circuit 100 and the like in this embodiment.

  The light source circuit 810 includes, for example, a plurality of LEDs as a light source. The plurality of LEDs are electrically connected to each other in series, for example. For this reason, the same current flows through the plurality of LEDs. When a current of a current target value determined by the dimming signal input circuit 180 flows through the plurality of LEDs, the plurality of LEDs are lit at the dimming degree indicated by the dimming signal.

The power factor correction circuit 110 includes, for example, a full-wave rectifier circuit DB11, an across the line capacitor C12, and a booster circuit 120.
The full wave rectifier circuit DB11 (rectifier circuit) receives an AC voltage from the AC power supply AC, performs full wave rectification on the input AC voltage, converts the voltage waveform into a pulsating current, and outputs the converted pulsating voltage. The full-wave rectifier circuit DB11 has, for example, four rectifier elements. The four rectifying elements are, for example, semiconductor diodes and are bridge-connected.
The across-the-line capacitor C12 is a capacitor having a relatively small capacitance (for example, 0.1 μF), and is connected to the output of the full-wave rectifier circuit DB11. The across-the-line capacitor C12 cuts high frequency noise.

  The booster circuit 120 receives the pulsating voltage output from the full-wave rectifier circuit DB11, boosts the input pulsating voltage, converts it to a DC voltage, and converts the converted DC voltage to the output voltage of the power factor improving circuit 110. Output as. Further, the booster circuit 120 increases the input power factor of the power supply circuit 100 by approximating the waveform of the envelope of the current value of the input pulsating current to the waveform of the voltage value of the input pulsating voltage. The input of the booster circuit 120 is electrically connected to the full-wave rectifier circuit DB11 in parallel with the across-the-line capacitor C12. The booster circuit 120 is, for example, a boost converter circuit, and includes a choke coil L21 (transformer), a switch Q22 (switching element), a rectifier element D23, a smoothing capacitor C24, a voltage detection circuit 125, and a current detection circuit 126. And a control IC 127 and a ground wiring GND. The ground wiring GND has a reference potential in the power supply circuit 100. The switch Q22 includes, for example, a semiconductor switch such as a MOSFET or a bipolar transistor, another electrical switch, a mechanical switch such as a relay, a switch based on another mechanism, and the like, and is turned on / off according to a control signal. The rectifying element D23 is, for example, a semiconductor diode. The smoothing capacitor C24 is a capacitor having a relatively large capacitance, for example, a capacitor having a polarity such as an electrolytic capacitor or a capacitor having no polarity.

The voltage detection circuit 125 detects an instantaneous value of a potential difference between the pair of input terminals of the booster circuit 120 (input voltage of the booster circuit 120), and outputs a signal (voltage detection signal) representing the detected instantaneous value of the voltage. To do. The voltage detection circuit 125 includes, for example, two resistors (voltage dividing resistors) that are electrically connected in series with each other and have a relatively large resistance value, and the voltage detection circuit 125 has a voltage dividing ratio determined by the ratio of the resistance values of the two resistors. A voltage obtained by dividing the input voltage is generated and output as a voltage detection signal.
The current detection circuit 126 detects an instantaneous value of the current flowing through the choke coil L21 (input current of the booster circuit 120) and outputs a signal (current detection signal) representing the detected instantaneous value of the current. The current detection circuit 126 has, for example, a winding that is magnetically coupled by being wound around the same core as the choke coil L21. The current detection circuit 126 is proportional to the current flowing through the choke coil L21 depending on the turn ratio between the choke coil L21 and the winding. A voltage is generated and output as a current detection signal.
The control IC 127 is, for example, an integrated circuit or a microcomputer (hereinafter referred to as “microcomputer”), and generates a control signal for controlling on / off of the switch Q22.

  One of the input terminals of the booster circuit 120 and one end of the choke coil L21 are electrically connected. Another input terminal of the booster circuit 120, one end of the switch Q22, the ground wiring GND, one end of the smoothing capacitor C24, and one of the output terminals of the booster circuit 120 are electrically connected. Another output terminal of the booster circuit 120, one end of the rectifying element D23, and the other end of the smoothing capacitor C24 are electrically connected. The other end of the choke coil L21, the other end of the switch Q22, and the other end of the rectifying element D23 are electrically connected. The switch Q22 is turned on / off according to the control signal generated by the control IC 127. The direction of the rectifying element D23 is forward with respect to the output of the full-wave rectifying circuit DB11. When the smoothing capacitor C24 is a capacitor having polarity, the direction of the smoothing capacitor C24 is forward with respect to the output of the full-wave rectifier circuit DB11.

  The control IC 127 controls on / off of the switch Q22 based on the voltage detection signal output from the voltage detection circuit 125 and the current detection signal output from the current detection circuit 126 according to control by the control circuit 140. For example, the control IC 127 adjusts the reference value of the current flowing through the choke coil L21 based on an instruction from the control circuit 140. When the voltage value of the DC voltage generated by the power factor correction circuit 110 is higher than the target voltage value, the control IC 127 decreases the reference value. Conversely, when the voltage value of the DC voltage generated by the power factor correction circuit 110 is lower than the target voltage value, the control IC 127 increases the reference value. The control IC 127 calculates the product of the adjusted reference value and a coefficient proportional to the instantaneous value of the input voltage of the booster circuit 120, and sets it as the threshold value. When the control IC 127 turns on the switch Q22, the current flowing through the choke coil L21 increases. The control IC 127 turns off the switch Q22 when the current flowing through the choke coil L21 reaches the calculated threshold value. The control IC 127 turns on the switch Q22 again when the current flowing through the choke coil L21 becomes zero. When the control IC 127 repeats this, the current flowing through the choke coil L21 becomes a triangular wave having a relatively high frequency (for example, several tens of kHz to several hundreds of kHz), and its envelope approximates the waveform of the input voltage of the booster circuit 120. It becomes the waveform. The smoothing capacitor C24 is charged by the current flowing through the choke coil L21, and a voltage higher than the peak value of the input voltage of the booster circuit 120 is generated at both ends of the smoothing capacitor C24.

  The power conversion circuit 130 (step-down converter circuit) is, for example, a buck converter circuit, and includes a switch Q31, a rectifying element D32 (freewheeling diode), a choke coil L33, a smoothing capacitor C34, a current detection circuit 135, and a comparator. 137 and a control IC 139. The pair of input terminals of the power conversion circuit 130 is electrically connected to the pair of output terminals of the power factor correction circuit 110 (boost circuit 120). The switch Q31 includes, for example, a semiconductor switch such as a MOSFET or a bipolar transistor, another electrical switch, a mechanical switch such as a relay, a switch based on another mechanism, and the like, and is turned on / off according to a control signal. Note that the switch Q31 may have a configuration including an insulating transmission circuit such as a pulse transformer or a photocoupler in order to convert the reference potential of the control signal. The rectifying element D32 is, for example, a semiconductor diode. The smoothing capacitor C34 is a capacitor having a relatively large capacitance, and is, for example, a capacitor having a polarity such as an electrolytic capacitor or a capacitor having no polarity.

The current detection circuit 135 detects the current value of the direct current output from the power conversion circuit 130 and outputs a signal (current detection signal) representing the detected current value. The current detection circuit 135 has, for example, a resistor (current detection resistor) that is electrically connected in series with the light source circuit 810 and has a relatively small resistance value, generates a voltage proportional to the current flowing through the resistor, and serves as a current detection signal. Output.
The comparator 137 is an error amplifier (error amplifier) or a microcomputer, for example, and receives the current detection signal output from the current detection circuit 135 and the signal output from the dimming signal input circuit 180, and the current detection circuit 135 The detected current value is compared with the current target value determined by the dimming signal input circuit 180, and a signal indicating which is greater is generated and output.
The control IC 139 is an integrated circuit or a microcomputer, for example, and generates a control signal for controlling on / off of the switch Q31.

  One of the input terminals of the power conversion circuit 130 and one end of the switch Q31 are electrically connected. Another input terminal of the power conversion circuit 130, one end of the rectifying element D32, one end of the smoothing capacitor C34, and one of the output terminals of the power conversion circuit 130 are electrically connected. Another output terminal of the power conversion circuit 130, one end of the choke coil L33, and the other end of the smoothing capacitor C34 are electrically connected. The other end of the switch Q31, the other end of the rectifying element D32, and the other end of the choke coil L33 are electrically connected. The direction of the rectifying element D32 is opposite to the output of the power factor correction circuit 110. When the smoothing capacitor C34 is a capacitor having polarity, the direction of the smoothing capacitor C34 is forward with respect to the output of the power factor correction circuit 110.

The control IC 139 adjusts the ON time for turning on the switch Q31 based on the signal output from the comparator 137. For example, when the current value of the direct current output from the power conversion circuit 130 is larger than the target current value, the control IC 139 shortens the on-time. Conversely, when the current value of the direct current output from the power conversion circuit 130 is smaller than the target current value, the control IC 139 increases the on-time. When the control IC 139 turns on the switch Q31, the current flowing through the choke coil L33 increases. The control IC 139 turns off the switch Q31 when the elapsed time from turning on the switch Q31 reaches the adjusted on time. The control IC 139 turns on the switch Q31 again when the elapsed time from turning on the switch Q31 reaches a predetermined time. The control IC 139 repeats this at a relatively high frequency (for example, several tens of kHz to several hundreds of kHz). The smoothing capacitor C34 is charged by the current flowing through the choke coil L33, and a voltage lower than the input voltage of the power conversion circuit 130 is generated at both ends of the smoothing capacitor C34. The voltage across the smoothing capacitor C34 (that is, the voltage value of the DC voltage output from the power conversion circuit 130) is adjusted so that the current value of the DC current output from the power conversion circuit 130 matches the current target value. As a result, the current value of the current flowing through the light source circuit 810 matches the current target value, so that the power supply circuit 100 operates as a constant current drive circuit.
For example, since the forward voltage drop of the light source varies depending on conditions such as the ambient temperature of the light source, the voltage (load voltage) generated across the light source circuit 810 varies. The power conversion circuit 130 feeds back the current flowing through the light source circuit 810 and adjusts the voltage (load voltage) generated at both ends of the light source circuit 810, so that the current of the current target value flows through the light source circuit 810.

The dimming signal input circuit 180 includes, for example, a control IC 181, an insulated transmission circuit 182, and a full-wave rectifier circuit DB 83.
The full wave rectification circuit DB83 receives the dimming signal output from the dimmer 820 and performs full wave rectification. This is because the polarity of the dimming signal may be reversed due to the wiring between the dimmer 820 and the power supply circuit 100, so that this can be corrected. The full-wave rectifier circuit DB83 has, for example, four rectifier elements. The four rectifying elements are, for example, semiconductor diodes and are bridge-connected.
The insulated transmission circuit 182 receives the dimming signal that has been full-wave rectified by the full-wave rectification circuit DB83, and transmits the dimming signal while being electrically insulated. This is because the reference potential in the dimmer 820 and the reference potential in the power supply circuit 100 may be different. The insulated transmission circuit 182 is, for example, a photocoupler or a pulse transformer.
The control IC 181 is, for example, an integrated circuit or a microcomputer. The control IC 181 receives the dimming signal transmitted by the insulated transmission circuit 182, calculates a current target value based on the input dimming signal, and outputs a signal representing the calculated current target value. The signal output from the control IC 181 represents the calculated current target value by, for example, a voltage value (average value, effective value, etc.), a duty ratio, or the like. For example, the higher the voltage average value of the signal output from the control IC 181, the larger the current target value.

  The control circuit 140 is, for example, a circuit configured by analog parts or digital parts, an integrated circuit, a microcomputer, or the like. The control circuit 140 determines the voltage target value of the DC voltage generated by the power factor correction circuit 110 as low as possible within a range that satisfies the following conditions. This is because the conversion efficiency of the power factor correction circuit 110 and the power conversion circuit 130 is higher when the voltage value of the DC voltage generated by the power factor improvement circuit 110 is lower.

  The first condition is that the voltage target value is higher than the voltage (load voltage) generated at both ends of the light source circuit 810 when the current of the current target value flows through the light source circuit 810. This is because the voltage value of the DC voltage output by the power conversion circuit 130 does not become higher than the voltage value of the DC voltage input by the power conversion circuit 130. For example, when the light source circuit 810 is a circuit in which an LED having a forward drop voltage of 3 V is used as a light source and 50 light sources are electrically connected in series, the load voltage is 150 V (= 3 V × 50). If there is a voltage drop in the current detection circuit 135, it is necessary to further increase the voltage target value in consideration of the voltage drop. For example, if the voltage drop in the current detection circuit 135 is 0.5 V, the voltage target value needs to be higher than 150.5 V (= 150 V + 0.5 V).

  The second condition is that the voltage target value is higher than the voltage peak value of the AC voltage input by the power factor correction circuit 110. This is because if the voltage value of the DC voltage output by the booster circuit 120 is made lower than the voltage value of the pulsating voltage input by the booster circuit 120, the booster circuit 120 will not operate well and the power factor will deteriorate. The voltage value of the AC voltage supplied from the commercial power supply is, for example, 100V (nominal effective value; the same applies hereinafter) and 200V in Japan, and ranges from 100V to 254V including overseas. . Since an error of about ± 10% is expected in the actual voltage value, the power supply circuit 100 needs to be able to cope with an AC voltage having a voltage effective value of 85V to 280V.

  The third condition is to increase the voltage target value as the current value of the direct current output from the power factor correction circuit 110 is smaller. When the voltage value of the DC voltage output by the power factor correction circuit 110 is high, the conversion efficiency of the power factor correction circuit 110 is lowered, but the power factor is improved. This is because the power factor becomes worse when the current value of the direct current output from the power factor correction circuit 110 is small, such as during dimming, to compensate for this.

  The fourth condition is that the voltage target value of the DC voltage output from the power factor correction circuit 110 is not changed abruptly. Since the booster circuit 120 included in the power factor correction circuit 110 is a boost converter circuit, a transfer function having the change amount of the on-duty of the switch Q22 as an input and the change amount of the voltage value of the DC voltage output from the booster circuit 120 as an output. Has a zero. Depending on the on-duty value of the switch Q22, the transfer function that receives the change amount of the on-duty of the switch Q22 and outputs the change amount of the voltage value of the DC voltage output from the booster circuit 120 has an unstable zero point. . Therefore, when the on-duty of the switch Q22 changes suddenly, the DC voltage output from the booster circuit 120 becomes unstable, and the voltage value of the DC voltage output from the booster circuit 120 swings in the direction opposite to the direction in which it is desired to increase or decrease (reverse swing). ) May occur. Since the voltage value of the DC voltage output by the power factor correction circuit 110 is determined by the on-duty of the switch Q22, the switch Q22 is turned on by not changing the voltage target value of the DC voltage output by the power factor correction circuit 110 abruptly. Since the sudden change of the duty can be prevented, the stability of the DC voltage output from the power factor correction circuit 110 is increased.

Control circuit 140 generates a signal indicating which is greater between the voltage value of the DC voltage output from power factor correction circuit 110 and the determined voltage target value, and outputs the generated signal. For example, the signal generated by the control circuit 140 indicates whether the voltage value of the DC voltage output from the power factor correction circuit 110 is larger or smaller than the voltage target value depending on whether the voltage value is higher or lower than a predetermined voltage reference value. . When the voltage value of the signal generated by the control circuit 140 is higher than the predetermined voltage reference value, it indicates that the voltage value of the DC voltage output from the power factor correction circuit 110 is larger than the voltage target value, and the control circuit 140 generates the voltage value. When the voltage value of the signal is lower than the predetermined voltage reference value, it indicates that the voltage value of the DC voltage output from the power factor correction circuit 110 is smaller than the voltage target value.
The control IC 127 operates according to the signal output from the control circuit 140. The control IC 127 determines whether the voltage value of the signal generated by the control circuit 140 is higher or lower than a predetermined voltage reference value, and operates based on the determination result.

  When the control IC 127, the control circuit 140, the comparator 137, the control IC 139, and the control IC 181 are configured by a microcomputer, they do not need to be independent and may be configured by one microcomputer.

  FIG. 3 is a characteristic diagram showing an example of characteristics of the power factor correction circuit 110 in this embodiment.

The horizontal axis represents the voltage peak value (hereinafter referred to as “input peak value”) of the AC voltage input to the power factor correction circuit 110. The vertical axis indicates the voltage target value of the DC voltage output by the power factor correction circuit 110 and determined by the control circuit 140.
A broken line 571 represents the minimum value of the input peak value, and is, for example, about 120 V (= 85 V × √2). A broken line 572 represents the maximum value of the input peak value, and is about 396 V (= 280 V × √2), for example. A broken line 573 represents the maximum value of the voltage generated at both ends of the light source circuit 810 when the current flowing through the light source circuit 810 matches the current target value, and is about 150V, for example. A broken line 574 represents a case where the input peak value is equal to the voltage target value determined by the control circuit 140 and is shown for reference.
Dashed line 580 represents set voltage V _tg . The set voltage V _tg is set in advance to the input peak value of the AC voltage that is used most frequently among the AC voltages input to the power factor correction circuit 110. For example, when the power supply circuit 100 is most frequently connected to a commercial power supply having a nominal voltage of 200 V (effective value), the set voltage V _tg is set to about 283 V (= 200 V × √2).
Dashed line 581 represents the first voltage. The first voltage is a voltage value lower than the set voltage V _tg, and is set in advance to an input peak value at an AC voltage that is used with a relatively low frequency among the AC voltages input to the power factor correction circuit 110.
Dashed line 582 represents the second voltage. The second voltage is a voltage value higher than the set voltage V _tg, and is set in advance to an input peak value in an AC voltage that is used with a relatively low frequency among the AC voltages input to the power factor correction circuit 110.
A solid line 511 and a broken line 541 represent the relationship between the input peak value and the voltage target value determined by the control circuit 140. A solid line 511 represents a case where the current value of the direct current output from the power factor correction circuit 110 is large, and a broken line 541 represents a case where the current value of the direct current output from the power factor improvement circuit 110 is small, such as during dimming. .

  For example, in Japan, in accordance with Article 44 of the Enforcement Regulations of the Electricity Business Law (Ministry of International Trade and Industry Ordinance No. 77 of October 18, 1995), when the standard voltage is 200V, the entrance voltage of the indoor wiring is maintained at 202V ± 20V. What to do is stipulated. Moreover, the voltage drop in the indoor wiring is about 4% or less. For this reason, when the nominal voltage of the AC power supply AC is 200 V (effective value), the input peak value is about 247 V (= (202 V−20 V) × 0.96 × √2) or more and about 314 V (= (202 V + 20 V) × 1 × √2) or less. Therefore, the first voltage is set to a value of about 247V or lower, for example, and the second voltage is set to a value of about 314V or higher, for example.

When the input peak value is between the first voltage and the second voltage, the control circuit 140 indicates the rate of change of the target voltage value with respect to the change of the input peak value, and the input peak value is the first voltage and the second voltage. The voltage should be smaller than when not between. Alternatively, as long as the input peak value is between the first voltage and the second voltage, the control circuit 140 may be configured to keep the target voltage value substantially constant.
When the input peak value is near the first voltage or the second voltage, the control circuit 140 indicates the rate of change of the target voltage value with respect to the change of the input peak value, and the input peak value is the first voltage and the second voltage. Make it larger than if it is between voltages. Alternatively, the control circuit 140 may be configured to change the target voltage value discontinuously at the point where the input peak value matches the first voltage or the second voltage.
When the input peak value is lower than the first voltage or higher than the second voltage, it is the same as when the input peak value is between the first voltage and the second voltage. That is, the control circuit 140 makes the rate of change of the target voltage value relative to the change of the input peak value smaller than when the input peak value is not between the first voltage and the second voltage, or sets the target voltage value to Keep almost constant.
Note that the set voltage is not limited to one, and a plurality of set voltages such as about 141 V and about 283 V may be provided.

In any case of the input peak value, the control circuit 140 makes the target voltage value larger than the input peak value. That is, the solid line 511 and the broken line 541 are located above the broken line 574 without intersecting with the broken line 574.
Similarly, regardless of the input peak value, the control circuit 140 makes the target voltage value larger than the maximum voltage across the light source circuit 810. That is, the solid line 511 and the broken line 541 are located above the broken line 573 without intersecting with the broken line 573.
Further, regardless of the input peak value, the control circuit 140 increases the target voltage value as the output current of the power factor correction circuit 110 decreases. That is, the broken line 541 is positioned above the solid line 511.

  An error of about ± 10% is expected in the voltage value of the AC voltage supplied from the commercial power supply, and the voltage value varies depending on the load condition. Setting is made by making the voltage target value of the DC voltage output by the power factor correction circuit 110 substantially constant in the vicinity of the most frequently used voltage value of the AC voltage input to the power factor correction circuit 110. Since it is possible to prevent a steep fluctuation in the DC voltage output from the power factor correction circuit 110 when the voltage value fluctuates during use with voltage, a sudden change in the on-duty of the switch Q22 can be prevented, and the power factor The stability of the output voltage of the improvement circuit 110 can be increased.

  FIG. 4 is a characteristic diagram showing an example of the characteristic of the power factor correction circuit 110 in this embodiment.

The horizontal axis represents the dimming degree represented by the dimming signal input to the dimming signal input circuit 180. The vertical axis indicates the voltage target value of the DC voltage output by the power factor correction circuit 110 and determined by the control circuit 140. Note that the higher the dimming degree, the larger the direct current output from the power supply circuit 100. Therefore, even if the horizontal axis indicates the direct current output from the power supply circuit 100, the same characteristic diagram is obtained.
It is assumed that the input peak value is constant.
A broken line 593 represents the minimum value (at the input peak value) of the voltage target value of the DC voltage output from the power factor correction circuit 110. A broken line 594 represents the maximum value (at the input peak value) of the voltage target value of the DC voltage output from the power factor correction circuit 110. A broken line 591 represents the minimum value of the dimming level represented by the dimming signal input to the dimming signal input circuit 180. A broken line 592 represents the maximum value of the dimming level represented by the dimming signal input to the dimming signal input circuit 180. A solid line 595 represents the relationship between the dimming degree and the voltage target value.

The control circuit 140 minimizes the voltage target value when the dimming degree is maximum, and maximizes the voltage target value when the dimming degree is minimum. The control circuit 140 changes the voltage target value at a substantially constant rate as the dimming degree changes, and continuously decreases the voltage target value as the dimming degree increases.
When the input peak value changes, the control circuit 140 changes the minimum value and the maximum value of the voltage target value, and accordingly, the solid line 595 translates vertically.

  FIG. 5 is a characteristic diagram showing an example of characteristics of the power factor correction circuit in the comparative example.

The circuit configuration of the power supply circuit in the comparative example is the same as that of the power supply circuit 100 in this embodiment. The power supply circuit in the comparative example is different from the power supply circuit 100 in this embodiment in the relationship between the dimming degree and the voltage target value calculated by the control circuit 140.
That is, the control circuit in the comparative example changes the voltage target value discontinuously at the point where the dimming degree matches the predetermined threshold value. For example, the control circuit in the comparative example maximizes the voltage target value when the dimming degree is smaller than the threshold value, and minimizes the voltage target value when the dimming degree is larger than the threshold value.

When the voltage target value of the DC voltage output from the power factor correction circuit changes stepwise as in the comparative example, the DC voltage output from the power factor correction circuit is steep due to the change in the dimming degree indicated by the dimmer. As a result, the stability of the output voltage of the power factor correction circuit decreases.
As shown in FIG. 4, if the voltage target value of the DC voltage output from the power factor correction circuit 110 changes linearly, the power factor correction circuit 110 caused by the change in the dimming degree indicated by the dimmer 820 A sudden change in the output DC voltage can be suppressed. For this reason, the stability of the output voltage of the power factor correction circuit 110 can be improved.

  According to this embodiment, even when there is a change in the voltage value of the AC voltage input to the power factor correction circuit 110 and the dimming degree indicated by the dimmer 820, the power factor correction circuit 110 outputs the change. Since the rapid change of the voltage target value of the DC voltage to be suppressed is suppressed, the stability of the output voltage of the power factor correction circuit 110 can be improved.

According to this embodiment, when the dimming degree represented by the dimming signal input to dimming signal input circuit 180 is high and the current value of the direct current output from power supply circuit 100 is large, power factor correction circuit 110 is The current value of the output direct current increases. In that case, since the control circuit 140 decreases the voltage target value of the DC voltage output from the power factor correction circuit 110, the efficiency of the power supply circuit 100 is increased.
Further, when the dimming degree represented by the dimming signal input to the dimming signal input circuit 180 is low and the current value of the direct current output from the power supply circuit 100 is small, the current of the direct current output from the power factor correction circuit 110 The value becomes smaller. In that case, since the control circuit 140 increases the voltage target value, the power factor of the power supply circuit 100 can be prevented from being lowered.

  As described above, the control circuit 140 changes the voltage target value of the DC voltage output from the power factor correction circuit 110, thereby reducing the power loss in the power supply circuit 100 while suppressing the decrease in the power factor of the power supply circuit 100. it can.

Since the power supply circuit 100 sets the voltage target value of the DC voltage output from the power factor correction circuit 110 to a value higher than the voltage peak value of the AC voltage input to the power factor correction circuit 110, the AC power supply AC having a different voltage value is used. Can be widely supported.
The power supply circuit 100 sets the voltage target value of the DC voltage output from the power factor correction circuit 110 to a value higher than the voltage across the light source circuit 810 when the current flowing through the light source circuit 810 is the current target value. 810 can be driven with a constant current.
The power supply circuit 100 sets the voltage target value of the DC voltage output from the power factor correction circuit 110 to a higher value as the current value of the DC current output from the power factor correction circuit 110 is smaller. It is possible to prevent an increase in harmonics and flickering of the light source due to abnormal control operation.
Since the power supply circuit 100 sets the voltage target value of the DC voltage output from the power factor correction circuit 110 as low as possible within the range satisfying the above conditions, the step-up ratio of the power factor correction circuit 110 becomes low and power loss is reduced. Can be suppressed.

The power loss in the booster circuit 120 includes, for example, power consumption of the control IC 127, switching loss of the switch Q22, loss in the choke coil L21, and the like. As the boost ratio of the booster circuit 120 (ratio of the effective voltage value of the output voltage to the effective voltage value of the input voltage) increases, the power handled by the choke coil L21 increases and the switching loss of the switch Q22 and the loss in the choke coil L21 increase. Thus, the power loss of the booster circuit 120 increases.
Further, since the voltage (load voltage) generated at both ends of the light source circuit 810 is substantially determined by the light output of the light source constituting the light source circuit 810, the step-down ratio (output) of the power conversion circuit 130 increases as the output voltage of the booster circuit 120 increases. The ratio of the effective voltage value of the input voltage to the effective voltage value of the voltage) increases. Therefore, as the output voltage of the booster circuit 120 increases, the power handled by the choke coil L33 increases, the loss in the switch Q31 and the choke coil L33 increases, and the power loss of the power conversion circuit 130 increases.
Therefore, by reducing the output voltage of the booster circuit 120 as much as possible within a range in which the power factor does not decrease and the light source flickers, the booster ratio of the booster circuit 120 and the step-down ratio of the power conversion circuit 130 are reduced. Loss can be reduced.

  Further, when the light output is decreased by dimming, the output voltage of the booster circuit 120 is increased, so that the current flowing through the power factor correction circuit 110 during dimming can be increased. Thereby, abnormal operation such as intermittent oscillation of the booster circuit 120 can be prevented, and flickering of the light source can be prevented.

In addition, for example, when a light source such as an LED breaks down and the current stops flowing through the light source circuit 810, the power conversion circuit 130 tries to pass a current through the light source circuit 810, and the DC voltage output from the power conversion circuit 130 May be the maximum voltage that can be generated by the power conversion circuit 130. Since the power conversion circuit 130 is a step-down circuit, a voltage higher than the voltage value of the input DC voltage cannot be generated. For this reason, the voltage value of the DC voltage output from the power conversion circuit 130 does not exceed the voltage value of the DC voltage output from the booster circuit 120.
Since the power supply circuit 100 reduces the output voltage of the booster circuit 120 as much as possible within a range in which the power factor does not decrease and the light source flickers, the light source circuit 810 that is the part closest to the user and the luminaire installer is used. It is possible to prevent the voltage at both ends from increasing, and safety is increased.

  The control circuit 140 changes the target voltage value of the DC voltage output from the power factor correction circuit 110 to change the target voltage value of the DC voltage output from the power factor correction circuit 110 as compared with the case where the target voltage value of the boost circuit 120 is fixed. Since the step-up ratio can be kept low, the choke coil L21 can be reduced in size, and the component cost can be reduced, and the power supply circuit board can be reduced in size by reducing the mounting area.

The power supply device (100) in this embodiment includes a power factor correction circuit (110), a control circuit (140), and a dimming signal input circuit (180).
The power factor correction circuit receives an AC voltage, converts the input AC voltage into a DC voltage, outputs the converted DC voltage, and increases the power factor of the input AC current.
The control circuit increases the voltage value of the DC voltage output from the power factor correction circuit as the voltage peak value of the AC voltage input to the power factor correction circuit increases.
The control circuit increases the voltage value of the DC voltage output from the power factor correction circuit as the dimming degree represented by the dimming signal input to the dimming signal input circuit is lower.

  Thereby, even when the range of the input AC voltage is wide and when dimming is performed, the power loss in the power supply device can be suppressed while preventing the power factor from being lowered.

A range of the AC voltage input to the power factor correction circuit (110) obtained by adding the voltage drop of the indoor wiring to the standard voltage is referred to as an AC voltage value fluctuation range.
The slope of the DC voltage output by the power factor correction circuit with respect to the AC voltage input to the power factor correction circuit within the range of the AC voltage value fluctuation range is expressed by the maximum value and the minimum value of the AC voltage value fluctuation range. The slope of the DC voltage output by the power factor correction circuit with respect to the AC voltage input to the power factor correction circuit is made smaller.

  Thereby, the stability of the DC voltage output from the power factor correction circuit can be enhanced.

  The lighting device (800) in this embodiment includes the power supply device (100) and a load circuit (light source circuit 810) having a light source that is turned on by power supplied from the power supply device.

  As a result, even when the input AC voltage range of the lighting device is wide and when dimming, the power loss in the power supply device can be suppressed while preventing the power factor from decreasing, and the output of the power factor correction circuit Voltage stability can be increased.

Embodiment 2. FIG.
The second embodiment will be described with reference to FIG.
In addition, about the part which is common in Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In this embodiment, another example of the characteristics of the power factor correction circuit 110 will be described.

  FIG. 6 is a characteristic diagram showing an example of the characteristics of the power factor correction circuit 110 in this embodiment.

The horizontal axis represents the dimming degree represented by the dimming signal input to the dimming signal input circuit 180. The vertical axis indicates the voltage target value of the DC voltage output by the power factor correction circuit 110 and determined by the control circuit 140. Note that the higher the dimming degree, the larger the direct current output from the power supply circuit 100. Therefore, even if the horizontal axis indicates the direct current output from the power supply circuit 100, the same characteristic diagram is obtained.
A broken line 597 represents the second set dimming degree. The second set dimming degree is a dimming degree that is not more than the maximum dimming degree and not less than the minimum dimming degree, and is set in advance to a dimming degree that is relatively low in use frequency.

  For example, in facility lighting equipment such as grid lighting, power consumption of lighting equipment is reduced by using daylight. When daylight from the window is available, such as during the daytime, the illuminance of the entire room is made constant by making the dimming degree of the lighting fixture near the window lower than the dimming degree of the lighting fixture in the center of the room and This technology reduces the power consumption of lighting fixtures. Here, the dimming degree of the lighting fixture near the window varies depending on the amount of daylight. Therefore, the dimming degree of the lighting fixture near the window varies depending on time, weather, sunshine conditions, and the like. For example, when the dimming degree of the lighting fixture in the center of the room is set to 100%, the dimming degree of the lighting fixture near the window is assumed to vary within a range of 80% to 100%. In this case, it can be said that the dimming degree of 80% to 100% is frequently used. Therefore, the second set dimming degree is set to, for example, 80% or smaller dimming degree. The lower limit value of the dimming level due to daylight use varies depending on the type of appliance and the manufacturing company, but the lower limit value of the lighting level near the window is 30% to 90% of the dimming level of the lighting fixture in the center of the room There are many. Therefore, the second set dimming degree is set to a value of 90% or less of the maximum dimming degree, for example.

When the dimming degree is the maximum dimming degree, the control circuit 140 sets the voltage target value to the minimum value.
When the dimming degree is between the second set dimming degree and the maximum dimming degree, the control circuit 140 makes the voltage target value substantially constant, for example, a minimum value. As a result, even when the dimming degree of the lighting fixture changes due to a change in daylight, it is possible to suppress a steep change in the voltage target value of the DC voltage output from the power factor correction circuit 110, thereby improving the power factor. The stability of the output voltage of the circuit 110 can be improved.
When the dimming degree is the minimum dimming degree, the control circuit 140 sets the voltage target value to the maximum value.
When the dimming level is between the minimum dimming level and the second set dimming level, the control circuit 140 decreases the voltage target value as the dimming level increases. The control circuit 140 changes the voltage target value at a substantially constant rate with respect to the change in the dimming degree.
When the dimming degree is in the vicinity of the second set dimming degree, the control circuit 140 gradually changes the amount of change in the voltage target value with respect to the change in the dimming degree so that the solid line 595 becomes a smooth curve. The control circuit 140 decreases the amount of change in the voltage target value as the dimming degree increases. Thereby, a sharp change in the voltage target value of the DC voltage output from the power factor correction circuit 110 can be suppressed.

  In the power supply device (100) in this embodiment, the control circuit (140) increases the voltage target value of the DC voltage output by the power factor correction circuit with a dimming degree of 90% or less.

  As a result, even when the dimming degree of the luminaire changes due to the daylight quantity, it is possible to suppress a steep change in the DC voltage output from the power factor correction circuit (110), so that the output voltage of the power factor correction circuit can be stabilized. Can increase the sex.

Embodiment 3 FIG.
The third embodiment will be described with reference to FIG.
Note that portions common to Embodiment 1 or Embodiment 2 are denoted by the same reference numerals and description thereof is omitted.

  In this embodiment, another example of the characteristics of the power factor correction circuit 110 will be described.

  FIG. 7 is a characteristic diagram showing an example of the characteristic of the power factor correction circuit 110 in this embodiment.

The horizontal axis represents the dimming degree represented by the dimming signal input to the dimming signal input circuit 180. The vertical axis indicates the voltage target value of the DC voltage output by the power factor correction circuit 110 and determined by the control circuit 140. Note that the higher the dimming degree, the larger the direct current output from the power supply circuit 100. Therefore, even if the horizontal axis indicates the direct current output from the power supply circuit 100, the same characteristic diagram is obtained.
Dashed line 596 represents the first set dimming degree.

  For example, if the dimmer 820 is a dial type and represents the dimming degree indicated by the user according to the rotation angle of the dial, and if the dial is further turned than the minimum dimming degree, the dimming degree represents an instruction to turn off the power. When turning on / off, the dimming level changes in a short time between the minimum dimming level and the target dimming level specified by the user. Therefore, it can be said that the lower the dimming degree, the higher the use frequency. Therefore, the first set dimming degree is set to, for example, a dimming degree of 20% or larger.

When the dimming degree is the minimum dimming degree, the control circuit 140 sets the voltage target value to the maximum value.
When the dimming degree is between the minimum dimming degree and the first set dimming degree, the control circuit 140 makes the voltage target value substantially constant, for example, the maximum value. As a result, it is possible to suppress a steep change in the voltage target value of the DC voltage output from the power factor correction circuit 110 in the vicinity of the minimum dimming level when the power is turned on and off, so that the power factor is improved when the power is turned on and off. The stability of the output voltage of the circuit 110 can be improved.
When the dimming degree is the maximum dimming degree, the control circuit 140 sets the voltage target value to the minimum value.
When the dimming degree is between the first set dimming degree and the maximum dimming degree, the control circuit 140 decreases the voltage target value as the dimming degree increases. The control circuit 140 changes the voltage target value at a substantially constant rate with respect to the change in the dimming degree.
When the dimming degree is in the vicinity of the first set dimming degree, the control circuit 140 gradually changes the amount of change in the voltage target value with respect to the change in dimming degree so that the solid line 595 becomes a smooth curve. The control circuit 140 increases the amount of change in the voltage target value as the dimming degree increases. Thereby, a sharp change in the voltage target value of the DC voltage output from the power factor correction circuit 110 can be suppressed.

Embodiment 4 FIG.
The fourth embodiment will be described with reference to FIG.
In addition, about the part which is common in Embodiment 1- Embodiment 3, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In this embodiment, yet another example of the characteristics of the power factor correction circuit 110 will be described.

  FIG. 8 is a characteristic diagram showing an example of characteristics of the power factor correction circuit 110 in this embodiment.

The horizontal axis represents the dimming degree represented by the dimming signal input to the dimming signal input circuit 180. The vertical axis indicates the voltage target value of the DC voltage output by the power factor correction circuit 110 and determined by the control circuit 140. Note that the higher the dimming degree, the larger the direct current output from the power supply circuit 100. Therefore, even if the horizontal axis indicates the direct current output from the power supply circuit 100, the same characteristic diagram is obtained.
Dashed line 596 represents the first set dimming degree. A broken line 597 represents the second set dimming degree.

The characteristic of the power factor correction circuit 110 is a combination of the second embodiment and the third embodiment.
That is, when the dimming degree is the minimum dimming degree, the control circuit 140 sets the voltage target value to the maximum value.
When the dimming degree is between the minimum dimming degree and the first set dimming degree, the control circuit 140 makes the voltage target value substantially constant, for example, the maximum value.
When the dimming degree is the maximum dimming degree, the control circuit 140 sets the voltage target value to the minimum value.
When the dimming degree is between the second set dimming degree and the maximum dimming degree, the control circuit 140 makes the voltage target value substantially constant, for example, a minimum value.
When the dimming level is between the first set dimming level and the second set dimming level, the control circuit 140 decreases the voltage target value as the dimming level increases. The control circuit 140 changes the voltage target value at a substantially constant rate with respect to the change in the dimming degree.
When the dimming degree is in the vicinity of the first set dimming degree, the control circuit 140 gradually changes the amount of change in the voltage target value with respect to the change in the dimming degree. The control circuit 140 increases the amount of change in the voltage target value as the dimming degree increases.
When the dimming degree is in the vicinity of the second set dimming degree, the control circuit 140 gradually changes the amount of change in the voltage target value with respect to the change in the dimming degree. The control circuit 140 decreases the amount of change in the voltage target value as the dimming degree increases.

According to this embodiment, the stability of the output voltage of the power factor correction circuit 110 can be increased even when the dimming degree changes due to fluctuations in daylight and the illuminance of the lighting fixture changes.
Further, according to this embodiment, the stability of the output voltage of the power factor correction circuit 110 can be enhanced even when the dimming degree changes sharply when the power is turned on and off.

The voltage target value of the DC voltage output by the power factor correction circuit (110) is the first interval in which the voltage target value becomes a substantially constant maximum value regardless of the dimming degree, regardless of the dimming degree. It consists of a third section having a substantially constant minimum value and a second section in which the voltage target value changes according to the dimming degree.
The power supply device (100) increases the voltage target value of the DC voltage output from the power factor correction circuit as the dimming degree is lower.
The control circuit (140) sets the voltage target value at the minimum dimming degree in the second section equal to the voltage target value in the first section, and sets the voltage target value at the maximum dimming degree in the second section as the voltage target value in the third section. The relationship between the dimming degree and the voltage target value in the second section is a straight line connecting the voltage target value at the minimum dimming degree and the voltage target value at the maximum dimming degree.

As a result, a steep change in the DC voltage output from the power factor correction circuit due to a change in the dimming degree can be suppressed, so that the stability of the output voltage of the power factor correction circuit can be enhanced.
In addition, the DC voltage output from the power factor correction circuit even when the dimming degree of the luminaire changes due to the daylight amount and the power is turned on / off by making the voltage target value constant in the first section and the third section. Therefore, the stability of the output voltage of the power factor correction circuit can be improved.

Embodiment 5 FIG.
The fifth embodiment will be described with reference to FIGS.
In addition, about the part which is common in Embodiment 1- Embodiment 4, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In this embodiment, another example of the characteristics of the power factor correction circuit 110 will be described.

  FIG. 9 is a characteristic diagram showing an example of the characteristics of the power factor correction circuit 110 in this embodiment.

  The horizontal axis indicates the voltage peak value of the AC voltage input to the power factor correction circuit 110. The vertical axis indicates the voltage target value of the DC voltage output by the power factor correction circuit 110 and determined by the control circuit 140.

  When the input peak value is lower than the first voltage and when the input peak value is higher than the second voltage, the control circuit 140 increases the voltage target value as the input peak value increases. The control circuit 140 makes the change amount of the voltage target value with respect to the change of the input peak value substantially constant, and changes the voltage target value in a substantially linear shape. The rate of change of the voltage target value with respect to the change of the input peak value is approximately 1, for example.

For example, in the case of facility lighting such as grid lighting, in most cases in Japan, the lighting device 800 is used by being connected to an AC power source AC having an AC voltage effective value of 200V.
However, in the case of overseas, the voltage effective value of the AC voltage of the AC power supply AC is used with various AC voltages such as 110V, 120V, 220V, 230V, 240V, and 250V.

FIG. 10 is a diagram illustrating the relationship between the nominal voltage of the commercial power source and the number of countries and regions using the commercial power source.
The horizontal axis indicates the nominal voltage (effective value) of the commercial power source. The vertical axis shows the number of countries and regions using the commercial power supply. When there are two or more types of commercial power sources used in one country or region, they may be counted in duplicate.

When the lighting device 800 is exported overseas, it is assumed that the lighting device 800 is used with various AC voltages.
Therefore, as shown in FIG. 9, the set voltage V _tg is set to, for example, about 283 V (= 200 V × √2), the voltage target value in the vicinity thereof is made substantially constant, and the voltage target values for the other input peak values are made substantially linear. To change. As a result, in a country where use is mainly assumed (for example, Japan), the stability of the output voltage of the power factor correction circuit 110 is enhanced, and the output of the power factor correction circuit 110 is also obtained at the voltage peak value of other AC voltages. Suppresses steep changes in voltage.

According to this embodiment, a steep change in the DC voltage output from the power factor correction circuit 110 can be suppressed even at an AC voltage value other than the voltage peak value V _tg of the set voltage. The output voltage stability can be improved.

Embodiment 6 FIG.
A sixth embodiment will be described with reference to FIG.
In addition, about the part which is common in Embodiment 1- Embodiment 5, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In this embodiment, another example of the characteristics of the power factor correction circuit 110 will be described.

  FIG. 11 is a characteristic diagram showing an example of the characteristic of the power factor correction circuit 110 in this embodiment.

The horizontal axis indicates the voltage peak value of the AC voltage input to the power factor correction circuit 110. The vertical axis indicates the voltage target value of the DC voltage output by the power factor correction circuit 110 and determined by the control circuit 140.
Dashed line 583 represents the third voltage. The third voltage is lower than the first voltage and is set in advance.

When the input peak value is lower than the third voltage, and when the input peak value is between the first voltage and the second voltage, the control circuit 140 determines the voltage with respect to the change of the input peak value. Keep the target value almost constant without changing it.
When the input peak value is between the third voltage and the first voltage, and when the input peak value is higher than the second voltage, the control circuit 140 increases the voltage target value as the input peak value increases. Increase The control circuit 140 sets the change rate of the voltage target value with respect to the change of the input peak value to, for example, approximately 1.
With the first voltage as a boundary, the control circuit 140 changes the voltage target value discontinuously. Before and after the second voltage and the third voltage, the control circuit 140 changes the rate of change of the voltage target value, but the voltage target value is continuous.

  As shown in FIG. 10, there are various commercial power supply nominal voltages (effective values) from 100 V to 277 V, but broadly divided into a low voltage group of 100 V to 150 V and a high voltage of 200 V to 277 V. Divided into groups. Therefore, the first voltage is set to a voltage (for example, about 236 V = 167 V × √2) corresponding to the vicinity of the middle of the blank zone between the two groups. Looking at the + 10% margin for 150V, the highest voltage in the low voltage group, it is 165V. When a margin of -15% is seen with respect to 200 V having the lowest voltage in the high voltage group, it is 170 V. That is, the effective voltage value of the AC voltage input to the power factor correction circuit 110 is not between 165V and 170V. Therefore, if the first voltage is set to the input peak voltage corresponding to the effective voltage value (that is, between about 233 V and about 240 V), the voltage target value changes discontinuously with the first voltage as a boundary. Even so, the output voltage of the power factor correction circuit 110 does not become unstable.

  The high voltage group has a large number in the range of 220V to 240V, and there are few countries using a commercial power supply with a higher nominal voltage. Therefore, the second voltage is set to, for example, an input peak value corresponding to the voltage effective value 264V with a margin of + 10% with respect to the voltage effective value 240V, or a value higher than that. Thereby, when the nominal voltage of the commercial power supply is 220V to 240V, the output voltage of the power factor correction circuit 110 is most stable, and even when the nominal voltage of the commercial power supply is higher than 240V, the output voltage of the power factor improvement circuit 110 is Stabilize.

  Similarly, the low voltage group has a large number in the range of 100V to 127V, and few countries use a commercial power supply having a higher nominal voltage. Therefore, the third voltage is set to, for example, an input peak value corresponding to the voltage effective value 140V with a margin of + 10% with respect to the voltage effective value 127V, or a value higher than about 198V. As a result, when the nominal voltage of the commercial power supply is 100V to 127V, the output voltage of the power factor correction circuit 110 is most stable, and even when the nominal voltage of the commercial power supply is higher than 127V, the output voltage of the power factor improvement circuit 110 is Stabilize.

  Thereby, the power efficiency of the power supply circuit 100 can be increased, and the stability of the output voltage of the power factor correction circuit 110 can be increased.

Embodiment 7 FIG.
A seventh embodiment will be described with reference to FIGS.
In addition, about the part which is common in Embodiment 1- Embodiment 6, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In this embodiment, a configuration in which the setting voltage is adaptively changed according to the input peak value, instead of setting the setting voltage in advance, will be described.

  FIG. 12 is a characteristic diagram showing an example of the characteristics of the power factor correction circuit 110 in this embodiment.

  The horizontal axis indicates the voltage peak value of the AC voltage input to the power factor correction circuit 110. The vertical axis indicates the voltage target value of the DC voltage output by the power factor correction circuit 110 and determined by the control circuit 140.

The control circuit 140 calculates a voltage target value based on the set voltage, the dimming degree, and the input peak value.
For example, the control circuit 140 calculates a product obtained by multiplying the set voltage by a predetermined coefficient (for example, 1.1) to obtain the second voltage. Here, the coefficient by which the set voltage is multiplied means a margin for fluctuations in the AC voltage of the commercial power supply. For example, multiplying by a factor of 1.1 means to see a margin for + 10% voltage fluctuation.
The control circuit 140 calculates a sum obtained by adding a predetermined bias (for example, 5 V) to the calculated second voltage and sets it as the minimum value of the voltage target value. The bias applied to the second voltage means the minimum value of the difference between the voltage target value and the input peak value. For example, applying a bias of 5 V means setting the voltage target value so that the voltage target value is 5 V or more higher than the input peak value.
The control circuit 140 calculates the voltage target value based on the calculated minimum value of the voltage target value and the dimming degree.
For example, the control circuit 140 adjusts the dimming degree based on the relationship between the predetermined dimming degree and the difference between the voltage target value and the minimum value of the voltage target value (for example, the relationship shown in FIG. 4, etc.). From this, the difference between the voltage target value and the minimum value of the voltage target value is calculated. The control circuit 140 calculates the voltage target value by adding the calculated difference to the minimum value of the voltage target value.
As a result, if the input peak value is lower than the second voltage, the voltage target value is higher than the input peak value by a bias or more.
Finally, the control circuit 140 corrects the calculated voltage target value based on the input peak value.
For example, the control circuit 140 calculates the sum of the bias applied to the second voltage and the input peak value. When the voltage target value is lower than the calculated sum, the control circuit 140 corrects the voltage target value and sets the calculated sum to the voltage target value.
Thereby, even when the input peak value is higher than the second voltage, the voltage target value becomes higher than the input peak value by the bias.

  Next, a process in which the control circuit 140 calculates the set voltage will be described.

  As described above, the nominal voltage value of the AC power supply AC connected to the power supply circuit 100 varies depending on the country or region where the lighting device 800 is installed, and two or more types of nominal voltage values are used in the same country. May exist. However, after the lighting device 800 is installed, the nominal voltage value of the AC power supply AC connected to the power supply circuit 100 does not frequently change.

  Therefore, for example, the control circuit 140 calculates a weighted average of past input peak values and sets it as the set voltage. The control circuit 140 calculates the average value by weighting the new input peak value observed at a time close to the current time and reducing the weight of the old input peak value observed at a time far from the current time. This is because the nominal voltage value of the AC power supply AC connected to the power supply circuit 100 may change due to a change in the installation location of the lighting device 800 or the like.

  FIG. 13 is a flowchart showing an example of the flow of the set voltage calculation process S610 in this embodiment.

For example, the control circuit 140 stores an initial value of the set voltage in advance. The control circuit 140 updates the stored set voltage every time the set voltage calculation process S610 is executed. The set voltage calculation process S610 does not need to be performed so frequently. For example, when the lighting device 800 is turned on, or the difference between the input peak values with respect to the set voltage exceeds a predetermined range (for example, ± 5%). The control circuit 140 executes a set voltage calculation process S610.
The set voltage calculation process S610 includes, for example, an input peak value measurement step S611, a first coefficient multiplication step S612, a second coefficient multiplication step S613, and a set voltage update step S614. The control circuit 140 starts the set voltage calculation process S610 from the input peak value measurement step S611.

The input peak value measuring step S611, the control circuit 140 measures the input peak value _{V p.}
In the first coefficient multiplication step S612, the control circuit 140 calculates a product αV _p obtained by multiplying the measured input peak value by a predetermined coefficient α. The coefficient α is a real number larger than 0 and smaller than 1, for example, a value of about 0.01. The smaller the value of the coefficient α, the greater the weighting of the old input peak value, and the set voltage is less likely to fluctuate with respect to the short-term fluctuation of the input peak value.
In the second coefficient multiplication step S613, the control circuit 140 calculates a product (1-α) V _tg obtained by multiplying the stored setting voltage V _tg by the coefficient (1-α).
In the set voltage update step S614, the control circuit 140 _adds the sum αV _p + () of the product αV _p calculated in the first coefficient multiplication step S612 and the product (1-α) V _tg calculated in the second coefficient multiplication step S613. 1-α) V _tg is calculated. The control circuit 140 stores the calculated sum αV _p + (1−α) V _tg as a new set voltage V _tg .

  The control circuit 140 calculates a voltage target value from the input peak value using the set voltage calculated in this way.

In the following example, it is assumed that the initial value of the set voltage stored in advance by the control circuit 140 is 286V. Further, it is assumed that the control circuit 140 calculates the voltage target value using the coefficient (1.1) and the bias (5 V) described above. In addition, the dimming degree is assumed to be 100%.
The nominal voltage (effective value) of the AC power supply AC to which the lighting device 800 is connected is 200V, and the effective voltage value of the AC voltage input by the power factor correction circuit 110 actually varies between 175V and 222V. If possible, the input peak value varies between about 247V and about 314V. When the set voltage is an initial value, the voltage target value calculated by the control circuit 140 is constant at about 320V. Even if the control circuit 140 updates the set voltage, the set voltage hardly changes. Therefore, the stability of the power factor correction circuit 110 is high and the power efficiency of the power supply circuit 100 is high.
The nominal voltage (effective value) of the AC power supply AC to which the lighting device 800 is connected is 100V, and the effective voltage value of the AC voltage input by the power factor correction circuit 110 actually varies between 91V and 107V. If possible, the input peak value varies between about 129V and about 151V. When the set voltage is an initial value, the voltage target value calculated by the control circuit 140 is constant at about 316V. Therefore, although the power factor correction circuit 110 has high stability, the power efficiency of the power supply circuit 100 is not necessarily high because the voltage target value is unnecessarily high. However, every time the control circuit 140 updates the set voltage, the set voltage decreases and converges to, for example, about 142V. Then, the voltage target value calculated by the control circuit 140 becomes constant at about 161V. For this reason, when the set voltage converges, the power efficiency of the power supply circuit 100 also increases.
Conversely, the nominal voltage (effective value) of the AC power supply AC to which the lighting device 800 is connected is 277 V, and the effective voltage value of the AC voltage input by the power factor correction circuit 110 is actually between 249 V and 305 V. The input peak value varies between about 353V and about 431V. When the set voltage is an initial value, the voltage target value calculated by the control circuit 140 is the input peak value + 5V. Therefore, although the power efficiency of the power supply circuit 100 is high, the stability of the power factor correction circuit 110 is not necessarily high. However, every time the control circuit 140 updates the set voltage, the set voltage increases and converges to, for example, about 392V. Then, the voltage target value calculated by the control circuit 140 becomes constant at about 436V. For this reason, when the set voltage converges, the stability of the power factor correction circuit 110 also increases.

  In order to prevent the set voltage updated by the control circuit 140 from becoming an abnormal value, an upper limit value and a lower limit value of the set voltage are provided, and the control circuit 140 updates the set voltage to be higher than the upper limit value, When the value is lower than the value, the configuration may be such that the set voltage is not updated. Alternatively, an upper limit value and a lower limit value of the input peak value are provided, and the control circuit 140 may be configured not to update the set voltage when the input peak value is higher than the upper limit value or lower than the lower limit value. .

Embodiment 8 FIG.
An eighth embodiment will be described with reference to FIGS.
In addition, about the part which is common in Embodiment 1- Embodiment 7, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In this embodiment, a configuration will be described in which a delay is provided in the fluctuation of the voltage target value to reduce the temporal fluctuation of the voltage target value.

  FIG. 14 is a characteristic diagram showing an example of the characteristic of the power factor correction circuit 110 in this embodiment.

The horizontal axis indicates the voltage peak value of the AC voltage input to the power factor correction circuit 110. The vertical axis indicates the voltage target value of the DC voltage output by the power factor correction circuit 110 and determined by the control circuit 140.
A solid line 511 and a broken line 541 represent the convergence value of the voltage target value. The convergence value of the voltage target value is a voltage target value after a sufficient time has elapsed since the input peak value or the dimming degree has changed. When the voltage target value calculated by the control circuit 140 does not match the convergence value in order to prevent the voltage target value from changing abruptly before a sufficient time has elapsed since the input peak value or dimming level has changed. There is.
A dotted line 521 represents the lower limit value of the voltage target value. Even when the voltage target value calculated by the control circuit 140 does not match the convergence value, the control circuit 140 always calculates a voltage target value larger than the lower limit value.

For example, the control circuit 140 calculates a new voltage target value based on the dimming degree, the input peak value, and the current voltage target value.
The control circuit 140 calculates a sum obtained by adding a predetermined first bias (for example, 10 V) to the larger of the input peak value and the maximum value of the voltage across the light source circuit 810 to obtain the minimum convergence value. The minimum convergence value is a value at which the minimum value of the voltage target value should converge. Based on the relationship between the predetermined dimming degree and the difference between the voltage target value and the minimum value of the voltage target value, the control circuit 140 calculates the minimum value of the voltage target value and the voltage target value from the dimming degree. The difference between is calculated. The control circuit 140 calculates the convergence value of the voltage target value by adding the calculated difference to the minimum convergence value.
The control circuit 140 calculates the difference between the calculated convergence value and the current voltage target value. The control circuit 140 compares the calculated absolute value of the difference with a predetermined maximum change amount. The maximum change amount is a maximum value at which the voltage target value may change in one calculation of the voltage target value.
When the absolute value of the calculated difference is smaller than the maximum change amount, the control circuit 140 sets the calculated convergence value as a new voltage target value.
When the absolute value of the calculated difference is larger than the maximum change amount, if the calculated difference is positive, the control circuit 140 adds the maximum change amount to the current voltage target value to obtain a new voltage target value. If negative, subtract the maximum amount of change from the current voltage target value to obtain a new voltage target value.
The control circuit 140 calculates a sum obtained by adding a predetermined second bias (for example, 5 V. The second bias is equal to or smaller than the first bias) to the input peak value. The control circuit 140 compares the calculated sum with the calculated new voltage target value. When the new voltage target value is smaller than the calculated sum, the control circuit 140 sets the calculated sum as the new voltage target value. This ensures that the voltage target value is higher than the input peak value by a second bias or more even when the input peak value suddenly increases.

  FIG. 15 is a timing chart showing an example of the operation of the power supply circuit 100 in this embodiment.

  The horizontal axis indicates time. The vertical axis represents voltage. A solid line 512 represents a voltage target value calculated by the control circuit 140. A dotted line 522 represents the convergence value of the voltage target value calculated by the control circuit 140. Dashed line 542 represents the input peak value.

For example, assume that the input peak value suddenly decreases at the time indicated by the broken line 551.
The control circuit 140 immediately changes the convergence value of the voltage target value following the change of the input peak value, but the voltage target value is changed only within a range not exceeding the maximum change amount. Since the voltage target value changes slowly, the stability of the power factor correction circuit 110 increases. After the time represented by the broken line 552, the voltage target value matches the convergence value, so that the power efficiency of the power supply circuit 100 also increases.

  FIG. 16 is a timing chart showing another example of the operation of the power supply circuit 100 according to this embodiment.

For example, assume that the input peak value suddenly increases at the time indicated by the broken line 553.
The control circuit 140 immediately changes the convergence value of the voltage target value following the change in the input peak value. Further, if the voltage target value is changed only within a range not exceeding the maximum change amount, the voltage target value falls below the input peak value, so the control circuit 140 inevitably changes the voltage target value rapidly, Set a value larger than the input peak value. Thereafter, the control circuit 140 changes the voltage target value within a range not exceeding the maximum change amount, and the voltage target value matches the convergence value at the time indicated by the broken line 554. For this reason, the stability of the power factor correction circuit 110 is increased, and the power efficiency of the power supply circuit 100 is also increased.

  The same applies when the dimming degree changes. That is, when the dimming degree changes rapidly, the control circuit 140 immediately changes the convergence value of the voltage target value, but changes the voltage target value only within a range not exceeding the maximum change amount. Unlike the case where the input peak value changes, when the dimming degree changes, the lower limit value of the voltage target value does not change, so the control circuit 140 always keeps the voltage target value within a range not exceeding the maximum change amount. To change.

Further, when the input peak value increases rapidly, if the increase amount is smaller than the difference between the first bias and the second bias, it is not necessary to increase the voltage target value rapidly. Therefore, if the difference between the first bias and the second bias is set large, a rapid increase in the voltage target value can be prevented and the stability of the power factor correction circuit 110 can be improved.
On the other hand, if the first bias is set to the same small value as the second bias, the voltage target value calculated by the control circuit 140 is lowered accordingly, so that the power efficiency of the power supply circuit 100 is increased.

  As described above, the configuration described in each embodiment is an example, and another configuration may be used. For example, the structure which combined the structure demonstrated in different embodiment may be sufficient, and the structure which replaced the structure of the non-essential part with the other structure may be sufficient.

The power supply apparatus (power supply circuit 100) described above includes a power factor correction circuit (110) and a control circuit (140).
The power factor correction circuit receives an AC voltage, converts the input AC voltage into a DC voltage, outputs the converted DC voltage, and increases the power factor of the input AC current.
The control circuit controls the voltage value of the DC voltage output by the power factor correction circuit. The smaller the current value of the DC current output by the power factor correction circuit, the lower the DC voltage output by the power factor correction circuit. Increase the voltage value.
Thereby, it is possible to prevent the power factor of the power supply device from being lowered when the current value of the direct current output from the power factor correction circuit is small.

The control circuit (140) increases the voltage value of the DC voltage output from the power factor correction circuit as the voltage value of the AC voltage input to the power factor correction circuit (110) increases.
Thereby, a power factor improvement circuit can be operated normally, and the fall of the power factor of a power supply device can be prevented.
In addition, as a result, the boost ratio of the booster circuit (120) can be kept low compared with the case where the voltage target value of the DC voltage output from the power factor correction circuit is fixed, so the choke coil (L21) can be downsized. Therefore, it is possible to reduce the component cost and the size of the power circuit board by reducing the mounting area.

The power supply device (100) further includes a power conversion circuit (130).
The power conversion circuit receives the DC voltage output from the power factor correction circuit (110), converts the input DC voltage to a voltage supplied to the load circuit, outputs the converted voltage, and outputs the converted voltage. A power supply instruction signal (a signal representing a current target value output from the dimming signal input circuit 180) for instructing the power supplied to the circuit is input, and the output current is adjusted based on the input power supply instruction signal To do.
Thereby, the electric power which a power supply device outputs can be adjusted.

The control circuit (140) increases the voltage value of the DC voltage output from the power factor correction circuit (110) as the power indicated by the supply power instruction signal input to the power conversion circuit (130) is smaller. .
Thereby, it is possible to prevent the power factor of the power supply device from being lowered when the power supplied from the power supply device to the load circuit is small and the current value of the direct current output from the power factor correction circuit is small.

The power factor correction circuit (110) includes a full-wave rectifier circuit (DB11), a capacitor (across the line capacitor C12), and a booster circuit (120).
The full-wave rectifier circuit performs full-wave rectification on the AC voltage and converts the voltage waveform into a pulsating voltage.
The capacitor is electrically connected to the output of the full-wave rectifier circuit to remove noise.
The booster circuit boosts the voltage converted by the full-wave rectifier circuit and converts it into a DC voltage.
The control circuit (140) controls the voltage value of the DC voltage output from the power factor correction circuit based on the voltage across the capacitor.
As a result, it is possible to prevent the power factor of the power supply device from being lowered when the current value of the direct current output from the power factor correction circuit is small and the voltage waveform across the capacitor changes.

The control circuit (140) makes the voltage target value of the DC voltage output from the power factor correction circuit (110) substantially constant between the lower limit and the upper limit of the fluctuation amount of the voltage peak value V _tg of the set voltage.
As a result, it is possible to prevent sudden fluctuations in the DC voltage output by the power factor correction circuit when there are fluctuations in the voltage value during use at the set voltage, so that sudden changes in the on-duty of the switch (Q22) can be prevented. And the stability of the output voltage of the power factor correction circuit can be increased.

The control circuit (140) changes the voltage target value of the DC voltage output from the power factor correction circuit (110) to a substantially linear shape with respect to the dimming degree.
As a result, a steep change in the DC voltage output from the power factor correction circuit due to a change in the dimming degree can be suppressed, so that the stability of the output voltage of the power factor correction circuit can be enhanced.

The control circuit (140) controls the voltage target of the DC voltage output by the power factor correction circuit (110) when the dimming degree is not less than the second set dimming degree (dashed line 597) and not more than the maximum dimming degree (dashed line 592). The value is a substantially constant minimum value.
As a result, even if the dimming level of the lighting fixture changes due to daylight, it is possible to suppress a steep change in the DC voltage output by the power factor correction circuit. Can be increased.

When the dimming degree is not less than the minimum dimming degree (dashed line 591) and not more than the first set dimming degree (dashed line 596), the control circuit (140) is a voltage target for the DC voltage output by the power factor correction circuit (110). The value is a substantially constant maximum value.
As a result, it is possible to suppress a steep change in the DC voltage output by the power factor correction circuit in the vicinity of the minimum dimming value when the power is turned on and off, so that the output voltage of the power factor correction circuit when the power is turned on and off is reduced. Stability can be increased.

When the voltage peak value of the AC voltage input to the power factor correction circuit (110) is not less than the minimum peak voltage (broken line 571) and not more than the first voltage (broken line 581), When the second voltage (broken line 582) is equal to or greater than the maximum peak voltage (broken line 572), the voltage target value of the DC voltage output by the power factor correction circuit is changed substantially linearly with respect to the voltage peak value of the AC voltage.
Thereby, even when it is assumed that the voltage peak value is used in various AC voltages whose voltage peak value is not less than the minimum peak voltage and not more than the maximum peak voltage, a steep change in the DC voltage output by the power factor correction circuit can be suppressed. Therefore, the stability of the output voltage of the power factor correction circuit can be improved.

The power supply device (100) includes a power factor correction circuit (110) and a control circuit (140).
The power factor correction circuit receives an AC voltage, converts the input AC voltage into a DC voltage, outputs the converted DC voltage, and increases the power factor of the input AC current.
The control circuit controls the target value (voltage target value) of the DC voltage output from the power factor correction circuit, and the higher the voltage value (input peak value) of the AC voltage input to the power factor correction circuit, The target value is increased, and the voltage value of the AC voltage is within a predetermined voltage range (from the first voltage to the second voltage, and when the third voltage is present, the second value is greater than the minimum value of the input peak value). The change rate of the target value with respect to the change in the voltage value of the AC voltage, compared to the case where the voltage value of the AC voltage is in another voltage range different from the predetermined voltage range. Make it smaller.
As a result, the change in the target value of the DC voltage output from the power factor correction circuit becomes small with respect to the change in the voltage value of the AC voltage input to the power factor correction circuit, so that the operation of the power factor correction circuit is stabilized. be able to.

The control circuit (140) makes the target value substantially constant regardless of the voltage value of the AC voltage when the voltage value of the AC voltage is within the predetermined voltage range.
As a result, even if the voltage value of the AC voltage input to the power factor correction circuit changes within a predetermined voltage range, the target value of the DC voltage output by the power factor correction circuit does not change. Can be stabilized.

The control circuit (140) increases the target value as the current value of the direct current output from the power factor correction circuit (110) decreases.
Thereby, the fall of a power factor can be prevented.

When the current value of the direct current output from the power factor correction circuit (110) is larger than a predetermined threshold (the dimming degree is higher than the second set dimming degree), the control circuit (140) The rate of change of the target value with respect to the change of the current value of the direct current is made smaller than when the current value is smaller than the predetermined threshold value.
Thus, even when the current value of the direct current output from the power factor correction circuit frequently fluctuates in a range larger than the threshold, such as when the power supply device is used in a daylighting lighting system, the change in the target value is small. Thus, the operation of the power factor correction circuit can be stabilized.

The control circuit (140), when the current value of the direct current output from the power factor correction circuit (110) is smaller than a predetermined threshold, than when the current value of the direct current is larger than the predetermined threshold. The rate of change of the target value with respect to the change of the current value of the direct current is reduced.
Thereby, even when the current value of the direct current output from the power factor correction circuit frequently fluctuates within a range smaller than the threshold value, the change of the target value is reduced, and the operation of the power factor correction circuit can be stabilized.

The said power supply device (100) is a power supply device used for the illuminating device (800) which has a light control function.
The predetermined threshold is a current value of a direct current output from the power factor correction circuit when dimming to a predetermined dimming degree (second set dimming degree) with a dimming degree of 90% or less.
Thereby, even when the direct current output from the power factor correction circuit changes with the change of the dimming degree, the operation of the power factor correction circuit can be stabilized.

The predetermined voltage range is a range of AC voltage input to the power factor correction circuit when the power factor correction circuit (110) inputs AC voltage from an AC power source having a predetermined nominal voltage (set voltage). It includes a range in which the voltage value can vary.
Thereby, when a power supply device is connected to the AC power source having the predetermined nominal voltage, the operation of the power factor correction circuit can be most stabilized.

The control circuit (140) calculates a voltage range for reducing the change rate of the target value based on the voltage value of the AC voltage input to the power factor correction circuit (110).
Thereby, it is possible to optimize the AC power supply to which the power supply device is connected, and the operation of the power factor correction circuit can be stabilized.

The control circuit (140) calculates the target value such that the absolute value of the change amount per unit time of the target value is equal to or less than a predetermined maximum change amount.
Thereby, the operation of the power factor correction circuit can be stabilized.

The illumination device (800) includes the power supply device (100) and a load circuit (810) having a light source that is turned on by the power supplied from the power supply device.
Thereby, it is possible to stabilize the operation while increasing the power factor of the lighting device and increasing the power efficiency.

  100 power supply circuit, 110 power factor correction circuit, 120 booster circuit, 125 voltage detection circuit, 126,135 current detection circuit, 127, 139, 181 control IC, 130 power conversion circuit, 137 comparator, 140 control circuit, 180 dimming Signal input circuit, 182 Insulated transmission circuit, 511, 512, 595 Solid line, 521, 522 Dotted line, 541, 542, 551, 552, 553, 554, 571, 572, 573, 574, 580, 581, 582, 583, 591 , 592,593,594,596,597 broken line, 800 illumination device, 810 light source circuit, 820 dimmer, AC AC power supply, C12 across the line capacitor, C24, C34 smoothing capacitor, D23, D32 rectifier, DB11, DB83 Full-wave rectifier circuit, GND ground wiring , L21, L33 Choke coil, Q22, Q31 switch, S610 set voltage calculation process, S611 input peak value measurement step, S612 first coefficient multiplication step, S613 second coefficient multiplication step, S614 set voltage update step.

Claims (15)

A power factor correction circuit and a control circuit;
The power factor correction circuit receives an AC voltage, converts the input AC voltage into a DC voltage, outputs the converted DC voltage, and increases the power factor of the input AC current.
The control circuit controls a target value of the DC voltage output from the power factor correction circuit. The higher the voltage peak value of the AC voltage input to the power factor correction circuit, the higher the target value, and the AC When the voltage peak value of the voltage is in a voltage range larger than the first voltage and smaller than the second voltage, the voltage of the AC voltage is higher than when the voltage peak value of the AC voltage is larger than the second voltage. to reduce the rate of change of the target value for the change in peak value,
The control circuit is further configured such that when the voltage peak value of the AC voltage is within a voltage range smaller than the third voltage smaller than the first voltage, the voltage peak value of the AC voltage is smaller than the third voltage. The rate of change of the target value relative to the change in the voltage peak value of the AC voltage is smaller than when the voltage voltage is greater than the first voltage and when the voltage peak value of the AC voltage is greater than the second voltage. A power supply device characterized by that. The control circuit sets the target value to be substantially constant regardless of the voltage value of the AC voltage when the voltage value of the AC voltage is within a voltage range that reduces the rate of change of the target value. The power supply device according to claim 1 . The power supply device further includes a dimming signal input circuit,
The dimming signal input circuit inputs a dimming signal that indicates the dimming degree of the light source that is turned on by the power supplied from the power supply device,
The power supply apparatus according to claim 1, wherein the control circuit increases the target value as the dimming degree indicated by the dimming signal input by the dimming signal input circuit is small.   A power factor correction circuit and a control circuit;
  The power factor correction circuit receives an AC voltage, converts the input AC voltage into a DC voltage, outputs the converted DC voltage, and increases the power factor of the input AC current.
  The control circuit controls a target value of the DC voltage output from the power factor correction circuit. The higher the voltage peak value of the AC voltage input to the power factor correction circuit, the higher the target value, and the AC When the voltage peak value of the voltage is in a voltage range larger than the first voltage and smaller than the second voltage, the voltage of the AC voltage is higher than when the voltage peak value of the AC voltage is larger than the second voltage. Reduce the rate of change of the target value relative to the peak value change,
  The control circuit is further configured such that when the voltage peak value of the AC voltage is within a voltage range that is greater than the first voltage and less than the second voltage, the voltage peak value of the AC voltage is the first voltage. The power supply apparatus characterized by making the rate of change of the target value with respect to the change of the voltage peak value of the AC voltage smaller than when it is smaller.   The control circuit sets the target value to be substantially constant regardless of the voltage value of the AC voltage when the voltage value of the AC voltage is within a voltage range that reduces the rate of change of the target value. The power supply device according to claim 4, wherein   The power supply device further includes a dimming signal input circuit,
  The dimming signal input circuit inputs a dimming signal that indicates the dimming degree of the light source that is turned on by the power supplied from the power supply device,
  6. The power supply apparatus according to claim 4, wherein the control circuit increases the target value as the dimming degree indicated by the dimming signal input by the dimming signal input circuit is small.   In a power supply device that supplies power to a light source,
  A power factor correction circuit and a control circuit;
  The power factor correction circuit receives an AC voltage, converts the input AC voltage into a DC voltage, outputs the converted DC voltage, and increases the power factor of the input AC current.
  The control circuit controls a target value of the DC voltage output from the power factor correction circuit. The higher the voltage peak value of the AC voltage input to the power factor correction circuit, the higher the target value, and the AC When the voltage peak value of the voltage is in a voltage range larger than the first voltage and smaller than the second voltage, the voltage of the AC voltage is higher than when the voltage peak value of the AC voltage is larger than the second voltage. Reduce the rate of change of the target value relative to the peak value change,
  The power supply device further includes a dimming signal input circuit,
  The dimming signal input circuit inputs a dimming signal that indicates the dimming degree of the light source,
  The power supply apparatus according to claim 1, wherein the control circuit increases the target value as the dimming degree indicated by the dimming signal input by the dimming signal input circuit is small.   The control circuit is instructed by the dimming signal inputted by the dimming signal input circuit when the dimming degree instructed by the dimming signal inputted by the dimming signal input circuit is larger than the second dimming degree. The power supply device according to claim 7, wherein a change rate of the target value with respect to a change in the dimming degree is made smaller than that in a case where the dimming degree is smaller than the second dimming degree.   The control circuit is instructed by the dimming signal inputted by the dimming signal input circuit when the dimming degree instructed by the dimming signal inputted by the dimming signal input circuit is smaller than the first dimming degree. The power supply device according to claim 7, wherein a change rate of the target value with respect to a change in the dimming degree is made smaller than that in a case where the dimming degree is larger than the first dimming degree.   The control circuit is instructed by the dimming signal input by the dimming signal input circuit when the dimming level indicated by the dimming signal input is smaller than the first dimming level and by the dimming signal input by the dimming signal input circuit. When the dimming degree is larger than the second dimming degree larger than the first dimming degree, the dimming degree indicated by the dimming signal input by the dimming signal input circuit is larger than the first dimming degree. The power supply device according to claim 7, wherein a change rate of the target value with respect to a change in the dimming degree is made smaller than a case where the dimming degree is smaller than the second dimming degree.   11. The power supply device according to claim 8, wherein the second dimming degree is a predetermined dimming degree with a dimming degree of 90% or less. The voltage range in which the control circuit decreases the rate of change of the target value is a range in which the voltage value of the AC voltage output by the AC power supply can vary in the AC power supply that outputs the AC voltage input by the power factor correction circuit. the power supply device according to any one of claims 1 to 11, which comprises a. The said control circuit calculates the voltage range which makes the rate of change of the said target value small based on the voltage value of the alternating voltage input into the said power factor improvement circuit, The any one of Claims 1-11 characterized by the above-mentioned. The power supply device described in 1. The said control circuit calculates the said target value so that the absolute value of the variation | change_quantity per unit time of the said target value may become below a predetermined maximum variation | change_quantity. The power supply described. A power supply device according to any one of claims 1 to 14 ,
A lighting device comprising: a load circuit having a light source that is turned on by power supplied from the power supply device.

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