Lighting devices and lighting fixtures

Abstract

To provide a lighting device and lighting fixture that make it easy to secure the applied voltage required by the light source. [Solution] The lighting device 1 comprises a converter circuit 11 and a first capacitor 12. The first capacitor 12 is connected in parallel to the light source 2 on the light source 2 side of the converter circuit 11. The converter circuit 11 has a primary winding 111 and a plurality of divider circuits X1. The plurality of divider circuits X1 are connected in series with each other. Each of the plurality of divider circuits X1 includes a secondary winding 112, a diode 113, and a second capacitor 114. The diode 113 is connected in series with the secondary winding 112. The second capacitor 114 is connected between the two ends of the series circuit between the secondary winding 112 and the diode 113.

Description

Technical Field

[0001] The present disclosure generally relates to a lighting device and a lighting fixture. More specifically, the present disclosure relates to a lighting device that lights a light source and a lighting fixture including the same.

Background Art

[0002] Patent Document 1 discloses a power supply device that supplies DC power to a light source. The power supply device includes an isolation transformer, a diode, and a capacitor. The transformer has a primary winding and a secondary winding. The capacitor is connected to the high potential side of the secondary winding via a diode.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the power supply device (lighting device) described in Patent Document 1, when the applied voltage required by the light source is large, it is necessary to use a diode with a high breakdown voltage in order to ensure the tolerance for the above applied voltage. However, a diode with a high breakdown voltage has a large loss during steady state, and there is a problem that it is difficult to ensure the applied voltage required by the light source.

[0005] An object of the present disclosure is to provide a lighting device and a lighting fixture that can easily ensure the applied voltage required by a light source.

Means for Solving the Problems

[0006] A lighting device according to one aspect of the present disclosure is a lighting device that lights a light source by applying an applied voltage to the light source. The lighting device comprises a converter circuit that converts a supply voltage supplied from an external power source into the applied voltage, and a first capacitor. The first capacitor is connected in parallel to the light source on the light source side of the converter circuit. The converter circuit has a primary winding and a plurality of divider circuits. The plurality of divider circuits are connected in series with each other. Each of the plurality of divider circuits includes a secondary winding, a diode, and a second capacitor. The secondary winding is magnetically coupled to the primary winding. The diode is connected in series with the secondary winding. The second capacitor is connected between the two ends of the series circuit between the secondary winding and the diode.

[0007] A lighting fixture according to one aspect of this disclosure comprises the lighting device and the light source. [Effects of the Invention]

[0008] According to this disclosure, there is an advantage in that it is easy to secure the applied voltage required by the light source. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram of the lighting device and lighting fixture according to this embodiment. [Modes for carrying out the invention]

[0010] The embodiments and modifications described below are merely examples of the present disclosure. This disclosure is not limited to these embodiments and modifications, and various modifications are possible depending on the design, etc., as long as they do not depart from the technical idea of ​​the present disclosure. The figures described in the embodiments and modifications below are schematic diagrams, and the ratios of the size and thickness of each component in the figures do not necessarily reflect the actual dimensional ratios.

[0011] (Embodiment) (1) Overview The following describes the outline of the lighting device 1 and lighting fixture 10 according to this embodiment with reference to Figure 1.

[0012] The lighting device 1 according to this embodiment lights up the light source 2 by applying an applied voltage to the light source 2. As shown in Figure 1, the lighting device 1 of this embodiment comprises an isolated converter circuit 11 and a first capacitor 12. The converter circuit 11 converts the supply voltage supplied from the external power supply 3 into an applied voltage. The first capacitor 12 is connected in parallel to the light source 2 on the light source 2 side of the converter circuit 11.

[0013] The converter circuit 11 has a primary winding 111 and a plurality of divider circuits X1 connected in series with each other. Each of the plurality of divider circuits X1 includes a secondary winding 112, a diode 113, and a second capacitor 114. The secondary winding 112 is magnetically coupled to the primary winding 111. The diode 113 is connected in series with the secondary winding 112. The second capacitor 114 is connected across the series circuit of the secondary winding 112 and the diode 113.

[0014] In the lighting device 1 of this embodiment, multiple divider circuits X1 are connected in series. Therefore, in the lighting device 1 of this embodiment, when an applied voltage is applied to the light source 2, the voltage applied to the diode 113 in each of the multiple divider circuits X1 becomes small. In other words, in the lighting device 1 of this embodiment, when the applied voltage required by the light source 2 is large, the withstand capability of each of the multiple diodes 113 to the above applied voltage can be ensured without using high-voltage diodes for each of the multiple diodes 113. Therefore, by using high-voltage diodes for each of the multiple diodes 113, the steady-state losses in each of the multiple diodes 113 can be suppressed. In short, the lighting device 1 of this embodiment has the advantage of making it easy to secure the applied voltage required by the light source 2.

[0015] In addition, the lighting fixture 10 according to the present embodiment includes a lighting device 1 according to the present embodiment and a light source 2 that is lit by an applied voltage applied from the lighting device 1.

[0016] Since the lighting fixture 10 of the present embodiment includes the lighting device 1 of the present embodiment, there is an advantage that it is easy to secure the applied voltage required by the light source 2.

[0017] (2) Detailed Configuration Next, each component of the lighting device 1 and the lighting fixture 10 according to the present embodiment will be described with reference to FIG. 1.

[0018] As shown in FIG. 1, the lighting fixture 10 of the present embodiment includes a lighting device 1 and a light source 2. The lighting fixture 10 is, for example, a tunnel lamp, but is not limited to a tunnel lamp, and may be, for example, a road lamp or a projector. Further, the lighting fixture 10 is not limited to outdoor lighting fixtures such as tunnel lamps, road lamps, and projectors, and may be, for example, an indoor lighting fixture such as a base light, a spotlight, or a downlight attached to an indoor ceiling or the like.

[0019] (2.1) Light Source The light source 2 is lit by an applied voltage applied from the lighting device 1. The applied voltage is, for example, a DC voltage of a magnitude capable of lighting the light source 2. The light source 2 has one or more light-emitting elements. The light-emitting element is, for example, an LED (Light-Emitting Diode).

[0020] (2.2) Lighting Device As shown in FIG. 1, the lighting device 1 includes a converter circuit 11, a first capacitor 12, a rectifier circuit 13, and a switch circuit 14. <病気の名前>

[0021] The lighting device 1 applies an applied voltage to the light source 2 to light the light source 2 by supplying a supply voltage from an external power source 3. The external power source 3 is, for example, an AC power source of 350 V or more (for example, AC415V, AC460V). Note that the external power source 3 is not limited to an AC power source of 350 V or more, and may be, for example, an AC power source of 200 V or an AC power source of 100 V. That is, the supply voltage supplied to the lighting device 1 from the external power source 3 is an AC voltage.

[0022] (2.2.1) Rectifier circuit The rectifier circuit 13 is, for example, a full-wave rectifier circuit configured by connecting four diodes in a bridge shape. The rectifier circuit 13 has a first input terminal, a second input terminal, a first output terminal, and a second output terminal. The first input terminal of the rectifier circuit 13 is connected to the first output terminal of the external power source 3. The second input terminal of the rectifier circuit 13 is connected to the second output terminal of the external power source 3. The first output terminal of the rectifier circuit 13 is connected to the first end of a primary winding 111, which will be described later, of the converter circuit 11. The second output terminal of the rectifier circuit 13 is connected to the source terminal of a switch element 141, which will be described later, of the switch circuit 14. The rectifier circuit 13 rectifies the supply voltage (AC voltage) supplied from the external power source 3 into a DC voltage. The rectifier circuit 13 outputs the rectified DC voltage to the converter circuit 11 when the switch element 141, which will be described later, of the switch circuit 14 is in an on state. Note that the rectifier circuit 13 may be a full-wave rectifier circuit having a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor).

[0023] Further, the rectifier circuit 13 is not limited to a full-wave rectifier circuit, and may be, for example, a half-wave rectifier circuit configured by one diode.

[0024] (2.2.2) Switch circuit As shown in Figure 1, the switch circuit 14 includes a switch element 141, which is, for example, an N-channel field-effect transistor. The switch element 141 has a drain terminal, a source terminal, and a gate terminal. The drain terminal of the switch element 141 is connected to the second end of the primary winding 111 of the converter circuit 11. The source terminal of the switch element 141 is connected to the second output terminal of the rectifier circuit 13. The gate terminal of the switch element 141 is connected to a switch switching unit (not shown). Note that the switch element 141 may also be an insulated-gate bipolar transistor (IGBT). In this case, the collector terminal of the switch element 141 is connected to the second end of the primary winding 111 of the converter circuit 11. The emitter terminal of the switch element 141 is connected to the second output terminal of the rectifier circuit 13. The gate terminal of the switch element 141 is connected to a switch switching unit.

[0025] The switch switching unit switches the conductivity state of the switch element 141. That is, the switch switching unit switches the switch element 141 from the off state (not conductive) to the on state (conductive), or switches the switch element 141 from the on state to the off state. The switch switching unit is composed of, for example, an integrated circuit. However, the switch switching unit and the switch circuit 14 may be composed of a single integrated circuit.

[0026] When the switch element 141 is in the ON state, it connects the second terminal of the primary winding 111 of the converter circuit 11 to the second output terminal of the rectifier circuit 13. That is, when the switch element 141 is in the ON state, the DC voltage rectified by the rectifier circuit 13 is output to the primary winding 111 of the converter circuit 11. On the other hand, when the switch element 141 is in the OFF state, it does not connect the second terminal of the primary winding 111 of the converter circuit 11 to the second output terminal of the rectifier circuit 13. That is, when the switch element 141 is in the OFF state, the DC voltage rectified by the rectifier circuit 13 is not output to the primary winding 111 of the converter circuit 11.

[0027] The switch circuit 14 further includes, for example, a capacitor 142, as shown in Figure 1. The capacitor 142 is connected in parallel with the switch element 141. More specifically, the capacitor 142 is connected between the drain terminal and the source terminal of the switch element 141. The capacitor 142 is a non-polarized capacitor.

[0028] (2.2.3) Converter Circuit The converter circuit 11 converts the supply voltage from the external power supply 3 into an applied voltage. In this embodiment, the converter circuit 11 converts the DC voltage rectified by the rectifier circuit 13 into an applied voltage of the voltage value required by the light source 2. The converter circuit 11 is, for example, an isolated flyback converter, which is a type of isolated DC / DC converter.

[0029] The converter circuit 11 includes a primary winding 111 and a plurality (two in this disclosure) of splitter circuits X1.

[0030] The first end (start of winding) of the primary winding 111 is connected to the first output terminal of the rectifier circuit 13. The second end (end of winding) of the primary winding 111 is connected to the drain terminal of the switch element 141.

[0031] Multiple divider circuits X1 are connected in series with each other. Each of the multiple divider circuits X1 has a first terminal and a second terminal. In this embodiment, the first terminal in each of the multiple divider circuits X1 is the connection point between the cathode of the diode 113 (described later) and the first terminal of the second capacitor 114 (described later). Similarly, in this embodiment, the second terminal in each of the multiple divider circuits X1 is the connection point between the second end (end of winding) of the secondary winding 112 (described later) and the second terminal of the second capacitor 114.

[0032] The first terminal of the first of the multiple divider circuits X1 is connected to the anode of the light-emitting element of the light source 2 via the circuit L1. The second terminal of the first divider circuit X1 is connected to the first terminal of the next divider circuit X1 connected to the first divider circuit X1. Here, "first divider circuit X1" refers to the first divider circuit X1 connected among multiple divider circuits X1 that are connected in series with each other.

[0033] The first terminal of the last of the multiple divider circuits X1 is connected to the second terminal of the divider circuit X1 that is connected before the last divider circuit X1. The second terminal of the last divider circuit X1 is connected to the cathode of the light-emitting element of the light source 2 via the circuit L2. The "last divider circuit X1" referred to here is the last of the multiple divider circuits X1 that are connected in series with each other.

[0034] The first terminal of the remaining divider circuit X1 among the multiple divider circuits X1 is connected to the second terminal of the divider circuit X1 that is connected before the aforementioned remaining divider circuit X1. The second terminal of the aforementioned remaining divider circuit X1 is connected to the first terminal of the divider circuit X1 that is connected after the aforementioned remaining divider circuit X1. Here, "remaining divider circuit X1" refers to the divider circuits X1 other than the first and last divider circuits X1 among the multiple divider circuits X1 that are connected in series with each other.

[0035] In this embodiment, the converter circuit 11 has two split circuits X1a and X1b. That is, there are two split circuits X1. Therefore, the first terminal of split circuit X1a is connected to the anode of the light-emitting element of the light source 2 via the circuit L1. The second terminal of split circuit X1a is connected to the first terminal of split circuit X1b. The second terminal of split circuit X1b is connected to the cathode of the light-emitting element of the light source 2 via the circuit L2.

[0036] Each of the multiple divider circuits X1 has a secondary winding 112, a diode 113, and a second capacitor 114.

[0037] The secondary winding 112 is magnetically coupled to the primary winding 111. That is, in the converter circuit 11, the primary winding 111 and the secondary windings 112 in each of the multiple divider circuits X1 are magnetically coupled to each other. As a result, when the switch switching unit is switched from the off state to the on state, the DC voltage rectified by the rectifier circuit 13 is output to the primary winding 111 of the converter circuit 11, causing an inductor current to flow in the secondary winding 112. At this time, an induced voltage due to the inductor current is generated across the ends of the secondary winding 112 as the applied voltage applied to the light source 2.

[0038] Diode 113 is connected in series with the secondary winding 112. That is, each of the multiple divider circuits X1 has a series circuit in which the secondary winding 112 and diode 113 are connected in series. The anode of diode 113 is connected to the first end (start of winding) of the secondary winding 112.

[0039] The second capacitor 114 is connected between the ends of the series circuit of the secondary winding 112 and the diode 113. That is, the second capacitor 114 is connected in parallel to the series circuit of the secondary winding 112 and the diode 113. The second capacitor 114 has a first terminal and a second terminal. The first terminal of the second capacitor 114 is connected to the cathode of the diode 113. The second terminal of the second capacitor 114 is connected to the second end (end of winding) of the secondary winding 112. In short, the second capacitor 114 is connected between the cathode of the diode 113 and the second end of the secondary winding 112. The second capacitor 114 is a smoothing capacitor.

[0040] The second capacitor 114 in this embodiment is a non-polar capacitor. In this disclosure, a "non-polar capacitor" is a capacitor that does not have polarity (for example, a film capacitor). For example, in a comparative example lighting device in which the second capacitor is a polarized capacitor, if a reverse voltage is applied to the second capacitor, the operation of the lighting device to apply the applied voltage to the light source may become unstable, and it may become impossible to apply the applied voltage to the light source. However, in the lighting device 1 of this embodiment, since the second capacitor 114 is a non-polar capacitor, even if a reverse voltage is applied to the second capacitor 114, it is possible to suppress the instability of the operation of the lighting device 1 to apply the applied voltage to the light source 2. In other words, the lighting device 1 of this embodiment has the advantage of being able to stably apply the applied voltage to the light source 2.

[0041] The capacitances of the second capacitors 114 in each of the multiple divider circuits X1 are equal to each other. In this disclosure, "capacitance" refers to a physical quantity that indicates the ability to store electric charge, and is also called electrostatic capacitance. Furthermore, in this disclosure, "equal" is not limited to strictly matching, and an error is permissible. The permissible error range is, for example, about 5%. With the above configuration, the voltage applied to each of the multiple diodes 113 in order to apply the voltage to the light source 2 can be made equal. Therefore, it is possible to suppress the decrease in the durability of one of the multiple diodes 113, which would result from an increase in the voltage applied to one of the multiple diodes 113. In other words, there is an advantage in improving the durability of the multiple diodes 113. In this embodiment, since the second capacitors 114 in each of the multiple divider circuits X1 are nonpolar capacitors, the capacitance of the second capacitors 114 is, for example, 0.1 to 1.0 μF.

[0042] The number of turns of the secondary winding 112 in each of the multiple divider circuits X1 is equal to each other. With this configuration, the voltage applied to each of the multiple diodes 113 in order to apply the voltage to the light source 2 can be made more equal. As a result, the voltage applied to one of the multiple diodes 113 becomes larger, which can reduce the durability of that one diode 113. In other words, there is an advantage in that the durability of the multiple diodes 113 is improved.

[0043] (2.2.4) First Capacitor The first capacitor 12 is connected in parallel to the light source 2 on the light source 2 side of the converter circuit 11. The first capacitor 12 is a smoothing capacitor, similar to the second capacitor 114 in each of the multiple divider circuits X1.

[0044] The first capacitor 12 has a first terminal and a second terminal. The first terminal of the first capacitor 12 is connected to the circuit L1 that connects the first terminal in the first division circuit X1 to the anode of the light-emitting element of the light source 2. The second terminal of the first capacitor 12 is connected to the circuit L2 that connects the second terminal in the last division circuit X1 to the cathode of the light-emitting element of the light source 2. In this embodiment, the first terminal of the first capacitor 12 is connected to the circuit L1 that connects the first terminal in the division circuit X1a to the anode of the light-emitting element of the light source 2. In this embodiment, the second terminal of the first capacitor 12 is connected to the circuit L2 that connects the second terminal in the division circuit X1b to the cathode of the light-emitting element of the light source 2.

[0045] The first capacitor 12 in this embodiment is an electrolytic capacitor. The capacitance of the first capacitor 12, which is an electrolytic capacitor, is, for example, 100 to 1000 μF. The above configuration has the advantage that the pulsating component of the applied voltage applied to the light source 2 can be smoothed out more effectively. In this disclosure, the term "electrolytic capacitor" is assumed to refer to an electrolytic capacitor with polarity, but an electrolytic capacitor without polarity may also be used.

[0046] In this embodiment, the capacitance of the first capacitor 12 is greater than the capacitance of the second capacitor 114 in each of the multiple divider circuits X1. In other words, the capacitance of the second capacitor 114 in each of the multiple divider circuits X1 is less than or equal to the capacitance of the first capacitor 12. With this configuration, the second capacitor 114 in each of the multiple divider circuits X1 can be a capacitor having a capacitance equal to or smaller than that of the first capacitor 12. As a result, there is the advantage that the applied voltage required by the light source 2 can be easily secured.

[0047] The lighting device 1 may include a plurality of first capacitors 12, and each of the plurality of first capacitors 12 may be connected in parallel to the light source 2 on the side of the converter circuit 11 to the light source 2. In other words, multiple first capacitors 12 may be connected in parallel to the light source 2 on the side of the converter circuit 11 to the light source 2.

[0048] (3) Effects The lighting device 1 according to this embodiment comprises an isolated converter circuit 11 and a first capacitor 12. The converter circuit 11 converts the supply voltage supplied from an external power source 3 into an applied voltage. The first capacitor 12 is connected in parallel to the light source 2 on the light source 2 side of the converter circuit 11. The converter circuit 11 has a primary winding 111 and a plurality of divider circuits X1 connected in series with each other. Each of the plurality of divider circuits X1 includes a secondary winding 112, a diode 113, and a second capacitor 114. The secondary winding 112 is magnetically coupled to the primary winding 111. The diode 113 is connected in series with the secondary winding 112. The second capacitor 114 is connected between the ends of the series circuit of the secondary winding 112 and the diode 113. As a result, in the lighting device 1 of this embodiment, the voltage applied to each of the plurality of diodes 113 in order to apply the applied voltage to the light source 2 is reduced. In other words, in the lighting device 1 of this embodiment, when the applied voltage required by the light source 2 is large, the withstand capability of each of the multiple diodes 113 to the applied voltage can be ensured without using high-voltage diodes for each of the multiple diodes 113. Therefore, by using high-voltage diodes for each of the multiple diodes 113, the steady-state losses in each of the multiple diodes 113 can be suppressed. In short, the lighting device 1 of this embodiment has the advantage of making it easy to secure the applied voltage required by the light source 2.

[0049] In the lighting device 1 according to this embodiment, the capacitance of the second capacitor 114 in each of the multiple divider circuits X1 is less than or equal to the capacitance of the first capacitor 12. This allows the use of a capacitor with a capacitance less than or equal to that of the first capacitor 12 in the second capacitor 114 of each of the multiple divider circuits X1. As a result, there is an advantage in that the applied voltage required by the light source 2 can be easily secured.

[0050] In the lighting device 1 according to this embodiment, the capacitance of the second capacitor 114 in each of the multiple divider circuits X1 is equal to that of the others. This makes it possible to equalize the voltage applied to each of the multiple diodes 113 in order to apply the voltage to the light source 2. As a result, it is possible to suppress the decrease in the durability of one of the multiple diodes 113, which would result from an increased voltage being applied to one of the multiple diodes 113. In other words, there is an advantage in improving the durability of the multiple diodes 113.

[0051] In the lighting device 1 according to this embodiment, the number of turns of the secondary winding 112 in each of the multiple divided circuits X1 is equal to each other. This makes it possible to make the voltage applied to each of the multiple diodes 113 more equal in order to apply the voltage to the light source 2. As a result, it is possible to further suppress the decrease in the durability of one of the multiple diodes 113 that is affected by an increased voltage applied to that one diode 113. In other words, there is an advantage in that the durability of the multiple diodes 113 is further improved.

[0052] In the lighting device 1 according to this embodiment, the first capacitor 12 is an electrolytic capacitor. This has the advantage of being able to smooth out the pulsating component of the applied voltage applied to the light source 2.

[0053] In the lighting device 1 according to this embodiment, the second capacitor 114 is a non-polarized capacitor. This has the effect of suppressing instability in the operation of the lighting device 1 to apply the applied voltage to the light source 2, even when a reverse voltage is applied to the second capacitor. In other words, the lighting device 1 of this embodiment has the advantage of being able to stably apply the applied voltage to the light source 2.

[0054] The lighting fixture 10 according to this embodiment comprises a lighting device 1 according to this embodiment and a light source 2 that lights up by the applied voltage applied from the lighting device 1. The lighting fixture 10 of this embodiment has the advantage that it is easy to secure the applied voltage required by the light source 2 because it is equipped with the lighting device 1 of this embodiment.

[0055] (4) Variations The embodiments described above are merely one of many embodiments of this disclosure. The embodiments described above can be modified in various ways depending on the design, etc., as long as the objectives of this disclosure are achieved. The following modifications may be implemented by combining them as appropriate. Components similar to those in the embodiments described above are denoted by the same reference numerals and their description is omitted.

[0056] In the embodiment described above, the capacitances of the second capacitor 114 in each of the multiple divider circuits X1 are equal. However, the capacitances of the second capacitor 114 in each of the multiple divider circuits X1 may be different. With this configuration, the voltages applied to each of the multiple diodes 113 for applying the voltage to the light source 2 can be made different from each other. This has the advantage that by using diodes with different withstand voltages as diodes 113 in each of the multiple divider circuits X1, the withstand voltage of the diodes 113 can be ensured.

[0057] In the above embodiment, the number of turns of the secondary winding 112 in each of the multiple divider circuits X1 is equal to each other. However, the number of turns of the secondary winding 112 in each of the multiple divider circuits X1 may be different to each other. With this configuration, it is possible to more reliably ensure that the voltages applied to each of the multiple diodes 113 in order to apply the voltage to the light source 2 are different to each other. For this reason, there is an advantage in that by using diodes with different withstand voltages as diodes 113 in each of the multiple divider circuits X1, it becomes easier to ensure the withstand voltage of the diodes 113 to the above-mentioned applied voltage.

[0058] In the embodiment described above, the second capacitor 114 is a non-polarized capacitor, but it may be a polarized capacitor. In this disclosure, a "polarized capacitor" is a capacitor that has polarity.

[0059] In the embodiment described above, the first capacitor 12 of this embodiment is a polarized electrolytic capacitor, but it may also be a non-polarized capacitor.

[0060] (summary) The lighting device (1) of the first embodiment is a lighting device that lights up a light source (2) by applying an applied voltage to the light source (2). The lighting device (1) of the first embodiment comprises a converter circuit (11) that converts a supply voltage supplied from an external power source (3) into an applied voltage, and a first capacitor (12). The first capacitor (12) is connected in parallel to the light source (2) on the light source (2) side of the converter circuit (11). The converter circuit (11) has a primary winding (111) and a plurality of divider circuits (X1). The plurality of divider circuits (X1) are connected in series with each other. Each of the plurality of divider circuits (X1) includes a secondary winding (112), a diode (113), and a second capacitor (114). The secondary winding (112) is magnetically coupled to the primary winding (111). The diode (113) is connected in series with the secondary winding (112). The second capacitor (114) is connected across the series circuit between the secondary winding (112) and the diode (113).

[0061] This embodiment has the advantage of making it easier to secure the applied voltage required by the light source (2).

[0062] In the lighting device (1) of the second embodiment, in the first embodiment, the capacitance of the second capacitor (114) in each of the plurality of divider circuits (X1) is less than or equal to the capacitance of the first capacitor (12).

[0063] This embodiment has the advantage that the applied voltage required by the light source (2) can be easily secured.

[0064] In the lighting device (1) of the third embodiment, in the first or second embodiment, the capacitances of the second capacitor (114) in each of the plurality of divider circuits (X1) are equal to each other.

[0065] This embodiment has the advantage of improving the durability of multiple diodes (113).

[0066] In the lighting device (1) of the fourth embodiment, in the third embodiment, the number of turns of the secondary winding (112) in each of the plurality of divided circuits (X1) is equal to one another.

[0067] This embodiment has the advantage of further improving the durability of the multiple diodes (113).

[0068] In the lighting device (1) of the fifth embodiment, in the first or second embodiment, the capacitances of the second capacitor (114) in each of the plurality of divider circuits (X1) are different from each other.

[0069] According to this embodiment, there is an advantage in that by using diodes (113) with different withstand voltages in each of the multiple divider circuits (X1), the withstand voltage of the diodes (113) can be ensured.

[0070] In the sixth embodiment of the lighting device (1), in the fifth embodiment, the number of turns of the secondary winding (112) in each of the multiple divided circuits (X1) is different from one another.

[0071] According to this embodiment, there is an advantage in that by using diodes (113) with different withstand voltages in each of the multiple divider circuits (X1), the withstand voltage of the diodes (113) against the applied voltage can be more reliably ensured.

[0072] In the lighting device (1) of the seventh embodiment, in any one of the first to sixth embodiments, the first capacitor (12) is an electrolytic capacitor.

[0073] This embodiment has the advantage of being able to smooth out the pulsating component of the applied voltage applied to the light source (2).

[0074] In the lighting device (1) of the eighth embodiment, in any one of the first to seventh embodiments, the second capacitor (114) is a non-polarized capacitor.

[0075] This embodiment has the advantage that the applied voltage can be stably applied to the light source (2).

[0076] The 9th embodiment of the lighting fixture (10) comprises a lighting device (1) according to any one of the 1st to 8th embodiments and a light source (2).

[0077] This embodiment has the advantage of making it easier to secure the applied voltage required by the light source (2). [Explanation of Symbols]

[0078] 10 Lighting fixtures 1. Lighting device 2 light source 3 External power supply 11. Converter Circuit 12. First Capacitor 111 Primary winding 112 Secondary winding 113 Diode 114 Second Capacitor X1 split circuit

Claims

1. A lighting device that lights up a light source by applying an applied voltage to the light source, A converter circuit that converts the supply voltage supplied from an external power source into the applied voltage, The converter circuit is located on the light source side and includes a first capacitor connected in parallel to the light source, The aforementioned converter circuit is Primary winding and, It has multiple divider circuits connected in series with each other, Each of the above-mentioned plurality of divider circuits is The secondary winding is magnetically coupled to the primary winding, A diode connected in series with the secondary winding, A second capacitor connected between the two ends of the series circuit between the secondary winding and the diode, Lighting device.

2. The capacitance of the second capacitor in each of the plurality of divider circuits is less than or equal to the capacitance of the first capacitor. The lighting device according to claim 1.

3. The capacitances of the second capacitors in each of the plurality of divider circuits are equal to each other. The lighting device according to claim 1 or 2.

4. The number of turns of the secondary winding in each of the plurality of divided circuits is equal to each other. The lighting device according to claim 3.

5. The capacitances of the second capacitors in each of the plurality of divider circuits are different from each other. The lighting device according to claim 1 or 2.

6. The number of turns of the secondary winding in each of the plurality of divided circuits is different from one another. The lighting device according to claim 5.

7. The first capacitor is an electrolytic capacitor. The lighting device according to claim 1 or 2.

8. The second capacitor mentioned above is a non-polarized capacitor. The lighting device according to claim 1 or 2.

9. A lighting device according to claim 1 or 2, The light source comprises, Lighting fixtures.

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