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 having 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 first diode 113, a capacitor 114, and a second diode 115. The first diode 113 is connected in series with the secondary winding 112. The capacitor 114 is connected between the two ends of the series circuit between the secondary winding 112 and the first diode 113. The second diode 115 is connected in parallel with the capacitor 114. The anode of the first diode 113 is connected to one end of the secondary winding 112. The cathode of the first diode 113 is connected to the cathode of the second diode 115.

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 direct current power to a light source. The power supply device includes an isolation type 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 withstand voltage in order to ensure the tolerance for the above applied voltage. However, a diode with a high withstand voltage has a large loss during steady state, and there is a problem that it is difficult to secure 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 secure 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 up a light source by applying an applied voltage to the light source. The lighting device includes a converter circuit. The converter circuit converts a supply voltage supplied from an external power source into the applied voltage. 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 first diode, a capacitor, and a second diode. The secondary winding is magnetically coupled to the primary winding. The first diode is connected in series with the secondary winding. The capacitor is connected between the two ends of the series circuit of the secondary winding and the first diode. The second diode is connected in parallel with the capacitor. The anode of the first diode is connected to one end of the secondary winding. The cathode of the first diode is connected to the cathode of the second 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. [Figure 2] Figure 2 is a schematic diagram of the lighting device and lighting fixture according to the first modified example described above. [Figure 3] Figure 3 is a schematic diagram of the lighting device and lighting fixture according to the second modified example described above. [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. The lighting device 1 of this embodiment includes an isolated converter circuit 11. The converter circuit 11 converts the supply voltage supplied from the external power supply 3 into an applied voltage.

[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 first diode 113, a capacitor 114, and a second diode 115. The secondary winding 112 is magnetically coupled to the primary winding 111. The first diode 113 is connected in series with the secondary winding 112. The capacitor 114 is connected across the series circuit of the secondary winding 112 and the first diode 113. The second diode 115 is connected in parallel with the capacitor 114. The anode of the first diode 113 is connected to one end (start of winding) of the secondary winding 112. The cathode of the first diode 113 is connected to the cathode of the second diode 115.

[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 first 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 first diodes 113 to the above applied voltage can be ensured without using high-voltage diodes for each of the multiple first diodes 113. Therefore, by using high-voltage diodes for each of the multiple first diodes 113, the steady-state losses in each of the multiple first 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] Furthermore, 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 an applied voltage applied from the lighting device 1.

[0016] The lighting fixture 10 of this embodiment has the advantage of being able to easily secure the applied voltage required by the light source 2, since it is equipped with the lighting device 1 of this embodiment.

[0017] (2) Detailed configuration Next, the components of the lighting device 1 and lighting fixture 10 according to this embodiment will be described with reference to Figure 1.

[0018] As shown in Figure 1, the lighting fixture 10 of this embodiment comprises a lighting device 1 and a light source 2. The lighting fixture 10 is, for example, a tunnel light, but is not limited to a tunnel light; for example, it may be a street light or a floodlight. Furthermore, the lighting fixture 10 is not limited to outdoor lighting fixtures such as tunnel lights, street lights and floodlights; for example, it may be an indoor lighting fixture such as a base light, spotlight or downlight installed on the ceiling of a room.

[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 that allows the light source 2 to be lit. 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 rectifier circuit 13, and a switch circuit 14.

[0021] When a supply voltage is supplied from the external power source 3 to the lighting device 1, the applied voltage is applied to the light source 2 to light the light source 2. The external power source 3 is, for example, an AC power source of 350 V or more (for example, AC 415 V, AC 460 V). 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] [[ID=~4]](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 the 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 the 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. When the switch element 141, which will be described later, of the switch circuit 14 is in the on state, the rectified DC voltage is output to the converter circuit 11. Note that the rectifier circuit 13 may be a full-wave rectifier circuit having a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor).

[0023] Note that the rectifier circuit 13 is not limited to a full-wave rectifier circuit; for example, it may be a half-wave rectifier circuit composed of a single diode.

[0024] (2.2.2) Switch Circuits 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 of each of the multiple divider circuits X1 is the connection point between the cathode of the first diode 113 (described later), the first terminal of the capacitor 114 (described later), and the cathode of the second diode 115 (described later). Similarly, in this embodiment, the second terminal of 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), the second terminal of the capacitor 114, and the anode of the second diode 115.

[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 first diode 113, a capacitor 114, and a second diode 115.

[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] The first 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 the first diode 113 are connected in series. The anode of the first diode 113 is connected to the first end (start of winding) of the secondary winding 112.

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

[0040] The capacitor 114 in this embodiment is a polarized capacitor. In this disclosure, a "polarized capacitor" refers to a capacitor that has polarity. More specifically, the capacitor 114 in this embodiment is a polarized electrolytic capacitor. The capacitance of the polarized capacitor 114 is, for example, 100 to 1000 μF. The above configuration has the advantage of being able to more smoothly smooth the pulsating component of the applied voltage applied to the light source 2.

[0041] The capacitances of the 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 being exactly the same, and an error is permissible. The permissible error range is, for example, about 20%. With the above configuration, the voltage applied to each of the multiple first 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 first diodes 113 that would result from an increased voltage being applied to one of the multiple first diodes 113. In other words, there is an advantage in improving the durability of the multiple first diodes 113.

[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 first diodes 113 in order to apply the voltage to the light source 2 can be made more equal. As a result, it is possible to further suppress the decrease in the durability of one of the multiple first diodes 113 that would result from an increased voltage being applied to one of the multiple first diodes 113. In other words, there is an advantage in that the durability of the multiple first diodes 113 is further improved.

[0043] The second diode 115 is connected in parallel with the capacitor 114. More specifically, the second diode 115 is connected in parallel with both the capacitor 114 and the series circuit of the secondary winding 112 and the first diode 113. The cathode of the second diode 115 is connected to both the cathode of the first diode 113 and the first terminal of the capacitor 114. The anode of the second diode 115 is connected to both the second terminal of the secondary winding 112 and the second terminal of the capacitor 114.

[0044] For example, in a comparative example lighting device where the second diode is not connected in parallel with the capacitor, if a reverse voltage is applied to the 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 2. However, in the lighting device 1 of this embodiment, since the second diode 115 is connected in parallel with the capacitor 114, even if a reverse voltage is applied to the capacitor 114, the operation of the lighting device 1 to apply the applied voltage to the light source 2 can be made unstable, thus providing the effect of suppressing instability. 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.

[0045] (3) Effects The lighting device 1 according to this embodiment includes an isolated converter circuit 11. The converter circuit 11 converts a supply voltage supplied from an external power source 3 into an applied voltage. 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 first diode 113, a capacitor 114, and a second diode 115. The secondary winding 112 is magnetically coupled to the primary winding 111. The first diode 113 is connected in series with the secondary winding 112. The capacitor 114 is connected between the ends of the series circuit of the secondary winding 112 and the first diode 113. The second diode 115 is connected in parallel with the capacitor 114. The anode of the first diode 113 is connected to one end (start of winding) of the secondary winding 112. The cathode of the first diode 113 is connected to the cathode of the second diode 115. As a result, in the lighting device 1 of this embodiment, when an applied voltage is applied to the light source 2, the voltage applied to each of the multiple first diodes 113 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 first diodes 113 to the above applied voltage can be ensured without using high-voltage diodes for each of the multiple first diodes 113. Therefore, by using high-voltage diodes for each of the multiple first diodes 113, the steady-state losses in each of the multiple first 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.

[0046] In the lighting device 1 according to this embodiment, the capacitor 114 is a polarized capacitor. This has the advantage of being able to smooth out the pulsating component of the applied voltage applied to the light source 2.

[0047] In the lighting device 1 according to this embodiment, the capacitance of the 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 first 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 first diodes 113, which would result from an increased voltage being applied to one of the multiple first diodes 113. In other words, there is an advantage in improving the durability of the multiple first diodes 113.

[0048] 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 first 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 first diodes 113 that is affected by an increased voltage. In other words, there is an advantage in that the durability of the multiple first diodes 113 is further improved.

[0049] 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.

[0050] (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.

[0051] (4.1) First variation In the lighting device 1 of the above-described embodiment, capacitor 114 is a polarized capacitor. However, as shown in Figure 2, in the lighting device 1A of the first modified example, capacitor 114A is a non-polarized capacitor. In this disclosure, "non-polarized capacitor" refers to a capacitor that does not have polarity (for example, a film capacitor, etc.).

[0052] In the first modified lighting device 1A, since the capacitor 114A is a non-polarized capacitor, even when a reverse voltage is applied to the capacitor 114A, the lighting device 1 can more effectively suppress instability in its operation of applying 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.

[0053] (4.2) Second variation As shown in Figure 3, the second modified lighting device 1B further includes a second capacitor 12, which is different from the first capacitor 114 in the above-described embodiment, and is connected in parallel to the light source 2 on the light source 2 side of the converter circuit 11. The second capacitor 12 is a smoothing capacitor, similar to the first capacitor 114 in each of the multiple divider circuits X1. The second modified lighting device 1B has the advantage that the second capacitor 12 can further smooth the pulsating component of the applied voltage applied to the light source 2.

[0054] The second capacitor 12 has a first terminal and a second terminal. The first terminal of the second capacitor 12 is connected to the circuit L1 that connects the first terminal in the first split circuit X1 to the anode of the light-emitting element of the light source 2. The second terminal of the second capacitor 12 is connected to the circuit L2 that connects the second terminal in the last split circuit X1 to the cathode of the light-emitting element of the light source 2. In the second modified example, the first terminal of the second capacitor 12 is connected to the circuit L1 that connects the first terminal in the split circuit X1a to the anode of the light-emitting element of the light source 2. In the second modified example, the second terminal of the second capacitor 12 is connected to the circuit L2 that connects the second terminal in the split circuit X1b to the cathode of the light-emitting element of the light source 2.

[0055] In the second modification, the second capacitor 12 is an electrolytic capacitor. The capacitance of the second electrolytic capacitor 12 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 even further. Although it is assumed that the second capacitor 12 is a polarized electrolytic capacitor, it may also be a non-polarized electrolytic capacitor.

[0056] In the second modified example, the capacitance of the second capacitor 12 is greater than the capacitance of the first capacitor 114 in each of the multiple divider circuits X1. In other words, the capacitance of the first capacitor 114 in each of the multiple divider circuits X1 is less than or equal to the capacitance of the second capacitor 12. With this configuration, the first capacitor 114 in each of the multiple divider circuits X1 can be a capacitor with a capacitance equal to or smaller than that of the second capacitor 12. As a result, there is the advantage that the applied voltage required by the light source 2 can be easily secured.

[0057] (4.3) Other variations The following are some variations of the above-described embodiment. These variations may be implemented in combination as appropriate.

[0058] In the above embodiment, the capacitances of the capacitors 114 in each of the multiple divider circuits X1 are equal. However, the capacitances of the capacitors 114 in each of the multiple divider circuits X1 may be different. With this configuration, the voltages applied to each of the multiple first 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 the first diodes 113 in each of the multiple divider circuits X1, the withstand voltage of the first diodes 113 can be ensured.

[0059] 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 first 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 the first diodes 113 in each of the multiple divider circuits X1, it becomes easier to ensure the withstand voltage of the first diodes 113 to the above-mentioned applied voltage.

[0060] (summary) The first embodiment of the lighting device (1, 1A, 1B) is a lighting device that lights up a light source (2) by applying an applied voltage to the light source (2). The first embodiment of the lighting device (1, 1A, 1B) includes a converter circuit (11). The converter circuit (11) converts a supply voltage supplied from an external power source (3) into an applied voltage. 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 first diode (113), a capacitor (114, 114A), and a second diode (115). The secondary winding (112) is magnetically coupled to the primary winding (111). The first diode (113) is connected in series with the secondary winding (112). The capacitors (114, 114A) are connected across the series circuit between the secondary winding (112) and the first diode (113). The second diode (115) is connected in parallel with the capacitors (114, 114A). The anode of the first diode (113) is connected to one end of the secondary winding (112). The cathode of the first diode (113) is connected to the cathode of the second diode (115).

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

[0062] In the second embodiment of the lighting device (1, 1B), the capacitor (114) is a polarized capacitor, as in the first embodiment.

[0063] This embodiment has the advantage of being able to smooth out the pulsating component of the applied voltage applied to the light source (2).

[0064] In the third embodiment of the lighting device (1A), the capacitor (114A) is a non-polarized capacitor, as in the first embodiment.

[0065] This embodiment has the advantage that the applied voltage can be applied to the light source (2) in a stable manner.

[0066] In the lighting device of the fourth embodiment (1, 1A, 1B), in any one of the first to third embodiments, the capacitances of the capacitors (114, 114A) in each of the plurality of divider circuits (X1) are equal to each other.

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

[0068] In the fifth embodiment of the lighting device (1, 1A, 1B), in the fourth embodiment, the number of turns of the secondary winding (112) in each of the multiple divided circuits (X1) is equal to one another.

[0069] This embodiment has the advantage of further improving the durability of the multiple first diodes (113).

[0070] In the sixth embodiment of the lighting device (1, 1A, 1B), in any one of the first to third embodiments, the capacitances of the capacitors (114, 114A) in each of the multiple divider circuits (X1) are different from each other.

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

[0072] In the lighting device of the seventh embodiment (1, 1A, 1B), in the sixth embodiment, the number of turns of the secondary winding (112) in each of the multiple divided circuits (X1) is different from one another.

[0073] According to this embodiment, there is an advantage in that by using diodes with different withstand voltages as the first diode (113) in each of the multiple divider circuits (X1), it becomes easier to ensure the withstand voltage of the first diode (113) to the applied voltage.

[0074] The lighting device (1B) of the eighth embodiment further comprises a second capacitor (12) in any one of the first to seventh embodiments. The second capacitor (12) is a capacitor (114, 114A) different from the first capacitor (114, 114A), and is connected in parallel to the light source (2) on the light source (2) side of the converter circuit (11).

[0075] This embodiment has the advantage of further smoothing the pulsating component of the applied voltage applied to the light source (2).

[0076] In the ninth embodiment of the lighting device (1B), in the eighth embodiment, the capacitance of the first capacitor (114, 114A) in each of the plurality of divider circuits (X1) is less than or equal to the capacitance of the second capacitor (12).

[0077] This embodiment has the advantage that the applied voltage required by the light source (2) can be easily secured.

[0078] In the lighting device (1B) of the tenth embodiment, the second capacitor (12) is an electrolytic capacitor, as in the eighth or ninth embodiment.

[0079] This embodiment has the advantage of further smoothing the pulsating component of the applied voltage applied to the light source (2).

[0080] The 11th embodiment of the lighting fixture (10) comprises a lighting device (1, 1A, 1B) according to any one of the 1st to 10th embodiments, and a light source (2).

[0081] This embodiment has the advantage of making it easier to secure the applied voltage required by the light source (2). [Explanation of Symbols]

[0082] 10 Lighting fixtures 1, 1A, 1B lighting device 2 light source 3 External power supply 11. Converter Circuit 12. Second Capacitor 111 Primary winding 112 Secondary winding 113 First Diode 114, 114A First capacitor (capacitor) 115 Second Diode X1 split circuit

Claims

1. A lighting device that lights up a light source by applying an applied voltage to the light source, It includes a converter circuit that converts the supply voltage supplied from an external power source into the applied voltage, 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 first diode connected in series with the secondary winding, A capacitor connected between the two ends of the series circuit between the secondary winding and the first diode, The capacitor is connected in parallel with a second diode, The anode of the first diode is connected to one end of the secondary winding. The cathode of the first diode is connected to the cathode of the second diode. Lighting device.

2. The aforementioned capacitor is a polarized capacitor. The lighting device according to claim 1.

3. The aforementioned capacitor is a non-polarized capacitor. The lighting device according to claim 1.

4. The capacitances of the capacitors in each of the plurality of divider circuits are equal to each other. A lighting device according to any one of claims 1 to 3.

5. 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 4.

6. The capacitances of the capacitors in each of the plurality of divider circuits are different from each other. A lighting device according to any one of claims 1 to 3.

7. 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 6.

8. The system further comprises a second capacitor, which is different from the first capacitor and is connected in parallel to the light source on the light source side of the converter circuit. A lighting device according to any one of claims 1 to 3.

9. The capacitance of the first capacitor in each of the plurality of divider circuits is less than or equal to the capacitance of the second capacitor. The lighting device according to claim 8.

10. The second capacitor is an electrolytic capacitor. The lighting device according to claim 8.

11. A lighting device according to any one of claims 1 to 3, The light source comprises, Lighting fixtures.

Images