Lighting devices and lighting fixtures

Abstract

To provide a lighting device capable of reducing the effect of static electricity.SOLUTION: A lighting device 1 includes a circuit part 2. The circuit part 2 has a rectifier circuit 3, a power conversion circuit 4, an inductance element L1, and a bypass circuit 5. The rectifier circuit 3 rectifies AC voltage supplied from an AC power source and generates pulsating voltage. The power conversion circuit 4 converts the pulsating voltage generated by the rectifier circuit 3 into a DC voltage to be supplied to a light source 6. The inductance element L1 is electrically connected to the rectifier circuit 3 and the power conversion circuit 4 therebetween. The bypass circuit 5 bypasses the surge voltage generated in the inductance element L1.SELECTED DRAWING: Figure 1

Description

Technical Field

[0006]

[0001] The present disclosure generally relates to a lighting device and a lighting fixture, and more particularly to a lighting device having a rectifying circuit and a lighting fixture including the lighting device.

Background Art

[0002] The lighting device described in Patent Document 1 includes a pair of input terminals, an input circuit, a power conversion circuit, and a pair of output terminals. The pair of input terminals are connected to a power source and receive power supply from the power source. The input circuit has a rectifying element. The input circuit is connected to the pair of input terminals and transmits power from the pair of input terminals to the power conversion circuit. An LED module is connected to the pair of output terminals.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the lighting device described in Patent Document 1, when static electricity is applied, the voltage applied to the rectifying element increases, and the rectifying element may fail.

[0005] An object of the present disclosure is to provide a lighting device and a lighting fixture in which the influence of static electricity is reduced.

Means for Solving the Problems

[0006] The lighting device according to one aspect of the present disclosure includes a circuit unit. The circuit unit includes a rectifying circuit, a power conversion circuit, an inductance element, and a bypass circuit. Surge absorber andThe rectifier circuit rectifies the AC voltage supplied from the AC power source and generates a pulsating voltage. The power conversion circuit converts the pulsating voltage generated by the rectifier circuit into a DC voltage to be supplied to the light source. The inductance element is electrically connected between the rectifier circuit and the power conversion circuit. The bypass circuit bypasses the surge voltage generated in the inductance element. The power conversion circuit includes a voltage conversion circuit and a smoothing capacitor. The voltage conversion circuit includes a positive input terminal and a negative input terminal. The smoothing capacitor is connected between the positive input terminal and the negative input terminal of the voltage conversion circuit. The surge absorber is connected in parallel with the smoothing capacitor, downstream of the inductance element and the bypass circuit, and upstream of the smoothing capacitor.

[0007] A lighting fixture according to one aspect of the present disclosure comprises the lighting device and an outer casing. The outer casing has a conductive portion at the same potential as the housing. The outer casing houses the housing. [Effects of the Invention]

[0008] This disclosure has the advantage of being able to reduce the effects of static electricity. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a circuit block diagram of a lighting device according to Embodiment 1. [Figure 2] Figure 2 is a perspective view of a lighting fixture equipped with the same lighting device. [Figure 3] Figure 3 is a circuit block diagram of a lighting device for reference purposes. [Figure 4] Figure 4 is a circuit block diagram of the lighting device according to Embodiment 2. [Figure 5] Figure 5 is a circuit block diagram of the lighting device according to Embodiment 3. [Figure 6] Figure 6 is a circuit block diagram of the lighting device according to Embodiment 4. [Modes for carrying out the invention]

[0010] In each of the embodiments described below, the lighting devices and luminaires of this disclosure will be explained with reference to the drawings. However, each of the embodiments described below is only a part of the various embodiments of this disclosure. Each of the embodiments described below can be modified in various ways depending on the design, etc., as long as the objectives of this disclosure are achieved. In addition, each of the figures described in each of the embodiments described below is a schematic diagram, 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) (1) Overview The lighting device 1 is a device that converts an AC voltage to a DC voltage and supplies this DC voltage to a light source 6. As shown in Figure 1, the lighting device 1 of this embodiment includes a circuit section 2. The circuit section 2 includes a rectifier circuit 3, a power conversion circuit 4, an inductance element L1, and a bypass circuit 5. The rectifier circuit 3 rectifies the AC voltage supplied from the AC power source and generates a pulsating voltage. The power conversion circuit 4 converts the pulsating voltage generated by the rectifier circuit 3 into a DC voltage to be supplied to the light source 6. The inductance element L1 is electrically connected between the rectifier circuit 3 and the power conversion circuit 4. The bypass circuit 5 bypasses the surge voltage generated in the inductance element L1.

[0012] According to this embodiment, when static electricity is applied to the lighting device 1, the surge voltage caused by the static electricity can be bypassed by the bypass circuit 5. This reduces the surge voltage. Therefore, the possibility of the rectifier circuit 3 failing due to the application of the surge voltage can be reduced.

[0013] Furthermore, the inductance element L1 can suppress normal mode noise.

[0014] Since the inductance element L1 is provided at the subsequent stage of the rectifier circuit 3, the required insulation distance between the first end 101 and the second end 102 of the inductance element L1, and the required insulation distance between the winding of the inductance element L1 and the surrounding circuits are shortened. Therefore, the lighting device 1 can be miniaturized. The surrounding circuits are, for example, the rectifier circuit 3, the varistor Z2 and the capacitor 42 described later, etc.

[0015] Also, since the inductance element L1 is provided at the subsequent stage of the rectifier circuit 3, a pulsating current output from the rectifier circuit 3, rather than an alternating current, flows through the inductance element L1. Therefore, compared with the case where an alternating current flows through the inductance element L1, the peak-to-peak value of the current becomes smaller and the hysteresis loss becomes smaller.

[0016] (2) Details of the lighting device Hereinafter, the lighting device 1 of the present embodiment will be described in more detail. As shown in FIG. 1, the lighting device 1 includes a circuit unit 2 and a housing 8. In the present embodiment, the light source 6 will be described as not being a component of the lighting device 1, but the light source 6 may be a component of the lighting device 1. That is, the lighting device 1 may include the light source 6.

[0017] In addition, in FIG. 1, the stray capacitance FC1 generated between the circuit unit 2 and the housing 8 is illustrated by a circuit symbol representing a capacitor. In FIG. 1, the position where the circuit symbol corresponding to each stray capacitance FC1 is illustrated represents the position where the stray capacitance FC1 is generated, but the position where the stray capacitance FC1 is generated is not limited to the example of FIG. 1.

[0018] The housing 8 is made of, for example, metal. The housing 8 has conductivity. The housing 8 houses the circuit unit 2. For example, the circuit unit 2 is mounted on a substrate, and the housing 8 houses the substrate and the circuit unit 2. Note that the light source 6 may be housed in the housing 8 or may be disposed outside the housing 8.

[0019] The circuit unit 2 includes at least a rectifier circuit 3, a power conversion circuit 4, an inductance element L1, and a bypass circuit 5. Also, in this embodiment, as shown in FIG. 1, the circuit unit 2 further includes a fuse F1, a varistor Z1, a capacitor C1, a low-pass filter circuit LF1, and a varistor Z2. The low-pass filter circuit LF1 includes, for example, two inductance elements L11 and L12. The low-pass filter circuit LF1 is, for example, a common-mode line filter including two inductance elements L11 and L12 that are magnetically coupled to each other.

[0020] The circuit unit 2 further includes two input terminals 21 and 22, and two output terminals 23 and 24. The input terminals 21 and 22 and the output terminals 23 and 24 may each be terminals to which an electric wire is connected, or may be a part of a conductor (wiring) constituting the circuit unit 2.

[0021] The input terminals 21 and 22 are electrically connected to an AC power supply. Also, the input terminal 21 is on the non-grounded side, and the input terminal 22 is on the grounded side.

[0022] The first end of the fuse F1 is electrically connected to the input terminal 21. The second end of the fuse F1 is electrically connected to the first end of the inductance element L11. The second end of the inductance element L11 is electrically connected to the first input terminal 31 of the rectifier circuit 3.

[0023] The first end of the inductance element L12 is electrically connected to the input terminal 22. The second end of the inductance element L12 is electrically connected to the second input terminal 32 of the rectifier circuit 3.

[0024] The varistor Z1 is used as a surge absorber. Capacitor C1 is a filter capacitor. The first terminal of varistor Z1 and the first terminal of capacitor C1 are electrically connected to a conductor that electrically connects the second terminal of fuse F1 and the first terminal of inductance element L11. The second terminal of varistor Z1 and the second terminal of capacitor C1 are electrically connected to a conductor that electrically connects the input terminal 22 and the first terminal of inductance element L12.

[0025] The rectifier circuit 3 is a diode bridge containing four diodes D1 to D4. The anode of diode D1 is electrically connected to the first input terminal 31 of the rectifier circuit 3. The cathode of diode D1 is electrically connected to the positive terminal 33 (first output terminal) of the rectifier circuit 3.

[0026] The anode of diode D2 is electrically connected to the second input terminal 32 of the rectifier circuit 3. The cathode of diode D2 is electrically connected to the positive terminal 33 of the rectifier circuit 3.

[0027] The anode of diode D3 is electrically connected to the negative terminal 34 (second output terminal) of the rectifier circuit 3. The cathode of diode D3 is electrically connected to the first input terminal 31 of the rectifier circuit 3.

[0028] The anode of diode D4 is electrically connected to the negative terminal 34 of the rectifier circuit 3. The cathode of diode D4 is electrically connected to the second input terminal 32 of the rectifier circuit 3.

[0029] The rectifier circuit 3 outputs a pulsating voltage. The positive terminal 33 is a terminal that is at a higher potential than the negative terminal 34.

[0030] Thus, the rectifier circuit 3 is a diode bridge that full-wave rectifies an AC voltage. The rectifier circuit 3 has a positive terminal 33 and a negative terminal 34, and the pulsating voltage output by the rectifier circuit 3 is the voltage between the positive terminal 33 and the negative terminal 34.

[0031] A parallel circuit of an inductance element L1 and a bypass circuit 5 (resistor R1) is provided downstream of the rectifier circuit 3. That is, the bypass circuit 5 is connected in parallel with the inductance element L1. The bypass circuit 5 also includes a resistor R1. In this embodiment, the bypass circuit 5 consists only of the resistor R1.

[0032] The first end 101 of the inductance element L1 is electrically connected to the first end of the bypass circuit 5. The second end 102 of the inductance element L1 is electrically connected to the second end of the bypass circuit 5.

[0033] Furthermore, the first terminal 101 of the inductance element L1 is electrically connected to the positive terminal 33 of the rectifier circuit 3. The second terminal 102 of the inductance element L1 is electrically connected to the positive input terminal 411 of the voltage conversion circuit 41 (described later). The negative terminal 34 of the rectifier circuit 3 is electrically connected to the negative input terminal 412 of the voltage conversion circuit 41.

[0034] The first terminal of varistor Z2 and the first terminal of capacitor 42 (described later) are electrically connected to a conductor that electrically connects the second terminal 102 of inductance element L1 and the positive side input terminal 411. The second terminal of varistor Z2 and the second terminal of capacitor 42 are electrically connected to a conductor that electrically connects the negative terminal 34 of rectifier circuit 3 and the negative side input terminal 412.

[0035] The power conversion circuit 4 converts the pulsating voltage supplied from the rectifier circuit 3 into a DC voltage. The power conversion circuit 4 includes a voltage conversion circuit 41 and a capacitor 42. The capacitor 42 converts the pulsating voltage supplied from the rectifier circuit 3 into a DC voltage by smoothing it. The voltage conversion circuit 41 is located downstream of the capacitor 42. The voltage conversion circuit 41 converts the input DC voltage into a DC voltage of a predetermined magnitude. The voltage conversion circuit 41 is, for example, a linear regulator or a switching regulator.

[0036] The voltage conversion circuit 41 outputs a DC voltage to output terminals 23 and 24. The DC voltage output from the voltage conversion circuit 41 is applied to the light source 6 via output terminals 23 and 24. As a result, the light source 6 lights up.

[0037] The light source 6 includes, for example, one or more light-emitting diode elements, organic electroluminescent elements, or laser diode elements.

[0038] (3) Lighting fixtures Next, we will describe the lighting fixture 9 with reference to Figure 2.

[0039] The lighting fixture 9 comprises a lighting device 1 (see Figure 1) and an outer casing 90. The outer casing 90 has a conductive part 91. The conductive part 91 is conductive. The potential of the conductive part 91 is the same as that of the housing 8 (see Figure 1). The outer casing 90 houses the housing 8.

[0040] The conductive part 91 is made of, for example, metal. The conductive part 91 is formed in a box shape with an opening on one side.

[0041] As shown in Figure 2, the outer casing 90 has a cover 92 in addition to the conductive part 91. The cover 92 covers the opening of the conductive part 91. The cover 92 is translucent. The cover 92 is made of, for example, synthetic resin.

[0042] The lighting device 1 and the light source 6 are housed in the conductive part 91. Light emitted from the light source 6 is emitted through the cover 92.

[0043] The conductive part 91 is grounded. Furthermore, the conductive part 91 is electrically connected to the housing 8. That is, the housing 8 is grounded via the conductive part 91.

[0044] In this embodiment, the light source 6 is described as not being a component of the lighting fixture 9, but the light source 6 may be a component of the lighting fixture 9. In other words, the lighting fixture 9 may include a light source 6.

[0045] (4) Comparison with reference examples Figure 3 shows a lighting device 1P related to a reference example.

[0046] The lighting device 1P differs from the lighting device 1 of Embodiment 1 in that it does not have a bypass circuit 5.

[0047] In lighting devices 1 and 1P, when static electricity is applied to the housing 8, the inductance element L1 and the stray capacitance FC1 may resonate, potentially applying a high voltage to the inductance element L1. As a result, a high voltage equivalent to the voltage across the inductance element L1 may be applied to the diodes D1 to D4 of the rectifier circuit 3.

[0048] Furthermore, a voltage even greater than the voltage corresponding to the voltage across inductance element L1 may be applied to diodes D1 to D4 of the rectifier circuit 3. More specifically, when static electricity is applied to the housing 8, the inductance element L11 or L12 and the stray capacitance FC1 may resonate, potentially applying a high voltage to inductance element L11 or L12. As a result, a high voltage corresponding to the difference between the voltage across inductance element L1 and the voltage across inductance element L11 or L12 may be applied to diodes D1 to D4 of the rectifier circuit 3.

[0049] Diodes D1 to D4 are each susceptible to failure due to the application of high voltage. Therefore, as shown in Figure 3 of the reference example, a series circuit of two capacitors C3 is provided in the lighting device 1P, the first end of the series circuit is electrically connected to the negative terminal 34 of the rectifier circuit 3, and the second end is grounded, thereby mitigating the voltage applied to diodes D1 to D4. In Figure 3, the second end of the series circuit is grounded by being electrically connected to the housing 8.

[0050] In contrast, the lighting device 1 of Embodiment 1 does not include one or more capacitors C3 electrically connected between the housing 8 and the negative electrode circuit between the rectifier circuit 3 and the power conversion circuit 4. Here, capacitor C3 refers to a capacitor as an electronic component, and stray capacitance FC1 does not correspond to capacitor C3.

[0051] In the lighting device 1 of Embodiment 1, the bypass circuit 5 reduces the voltage applied to diodes D1 to D4.

[0052] Furthermore, in the reference example, instead of a series circuit of two capacitors C3, a varistor can be placed in the same position as this series circuit to mitigate the voltage applied to diodes D1 to D4. In the lighting device 1 of Embodiment 1, the voltage applied to diodes D1 to D4 can be mitigated without providing a varistor. That is, the lighting device 1 of Embodiment 1 does not include a varistor electrically connected between the housing 8 and the negative electrode circuit between the rectifier circuit 3 and the power conversion circuit 4.

[0053] Furthermore, in the reference example, the voltage applied to diodes D1 to D4 can be mitigated not only by providing a series circuit of two capacitors C3 or a varistor, but also by providing a surge absorber having a similar function. The series circuit of two capacitors C3 and the varistor are examples of surge absorbers. In the lighting device 1 of Embodiment 1, the voltage applied to diodes D1 to D4 can be mitigated without providing a surge absorber. That is, the lighting device 1 of Embodiment 1 does not have a surge absorber electrically connected between the housing 8 and the negative electrode circuit between the rectifier circuit 3 and the power conversion circuit 4.

[0054] In the lighting device 1 of Embodiment 1, the negative-side circuit between the rectifier circuit 3 and the power conversion circuit 4 is a conductor that electrically connects the negative terminal 34 to the negative-side input terminal 412 of the power conversion circuit 4. Even in a lighting device 1 that does not have a surge absorber in such a location, the voltage applied to diodes D1 to D4 can be mitigated by providing a bypass circuit 5. Examples of surge absorbers mentioned here include gap arresters, gas arresters, Zener diodes, and varistors.

[0055] (5) Variant The following are examples of modifications of Embodiment 1. These modifications may be implemented by combining them as appropriate. Furthermore, these modifications may be applied to Embodiments 2 to 4 as appropriate.

[0056] The rectifier circuit 3 in Embodiment 1 is a diode bridge that full-wave rectifies an AC voltage, but the rectifier circuit 3 may also be a circuit that half-wave rectifies an AC voltage.

[0057] Varistors Z1 and Z2 are examples of surge absorbers. Instead of varistors Z1 and Z2, other surge absorbers such as Zener diodes may be used.

[0058] At least one of the varistors Z1 and Z2, capacitor C1, and low-pass filter circuit LF1 may be omitted.

[0059] As shown in the reference example (see Figure 3), the lighting device 1 may further include one or more capacitors C3 or surge absorbers other than capacitor C3, electrically connected between the housing 8 and the negative electrode circuit between the rectifier circuit 3 and the power conversion circuit 4. The number of capacitors C3 may be one, or there may be two or more to prevent the circuit section 2 and the housing 8 from being electrically connected when one capacitor C3 fails. In addition, common-mode noise is effectively suppressed by forming an LC filter with one or more capacitors C3 and the inductance of the low-pass filter circuit LF1. In particular, when a switching regulator is used in the voltage conversion circuit 41, there is a concern that noise generated by switching may flow into the commercial power system, causing interference with other equipment connected to the commercial power system. Therefore, it is necessary to suppress the flowing noise.

[0060] (Embodiment 2) The lighting device 1A according to Embodiment 2 will be described below with reference to Figure 4. Components similar to those in Embodiment 1 are denoted by the same reference numerals and their descriptions are omitted.

[0061] In this embodiment, the configuration of the bypass circuit 5 differs from that of Embodiment 1. The bypass circuit 5 in this embodiment includes a resistor R1 and a capacitor C4. The capacitor C4 is connected in series with the resistor R1. The series circuit of the resistor R1 and the capacitor C4 is connected in parallel with the inductance element L1.

[0062] In this embodiment, as in Embodiment 1, the surge voltage due to electrostatic discharge can be bypassed by the bypass circuit 5. Furthermore, the presence of capacitor C4 suppresses the flow of the DC component and low-frequency component of the current into the bypass circuit 5. As a result, noise in the low-frequency band is suppressed.

[0063] As a variation of Embodiment 2, the bypass circuit 5 may be configured to include at least a capacitor C4. For example, the bypass circuit 5 may consist only of a capacitor C4. In this case as well, the capacitor C4 suppresses low-frequency noise, and the bypass circuit 5 can bypass surge voltages caused by static electricity.

[0064] (Embodiment 3) The lighting device 1B according to Embodiment 3 will be described below with reference to Figure 5. Components similar to those in Embodiment 1 are denoted by the same reference numerals and their description is omitted.

[0065] In this embodiment, the configuration of the bypass circuit 5 differs from that of Embodiment 1. The bypass circuit 5 of this embodiment includes a nonlinear resistive element 50 instead of the resistor R1. The bypass circuit 5 of this embodiment consists only of the nonlinear resistive element 50. The nonlinear resistive element 50 is connected in parallel with the inductance element L1.

[0066] The nonlinear resistive element 50 has the characteristic that its impedance decreases as the applied voltage increases. Examples of the nonlinear resistive element 50 in the bypass circuit 5 are Zener diodes such as TVS diodes and varistors.

[0067] By including a nonlinear resistive element 50 in the bypass circuit 5, surge voltages caused by electrostatic discharge can be bypassed by the bypass circuit 5. Furthermore, noise is suppressed by the nonlinear resistive element 50. By selecting a nonlinear resistive element 50 with a relatively small capacitance between its terminals, noise can be suppressed even further.

[0068] (Embodiment 4) The lighting device 1C according to Embodiment 4 will be described below with reference to Figure 6. Components similar to those in Embodiment 1 are denoted by the same reference numerals and their description is omitted.

[0069] In this embodiment, the configuration and arrangement of the bypass circuit 5 differ from those of Embodiment 1. The bypass circuit 5 in this embodiment includes a capacitor C5. The capacitor C5 is electrically connected between the positive terminal 33 and the negative terminal 34 in the preceding stage of the inductance element L1. More specifically, the first end of the capacitor C5 is electrically connected to a conductor that electrically connects the positive terminal 33 and the first end of the inductance element L1. The second end of the capacitor C5 is electrically connected to a conductor that electrically connects the negative terminal 34 and the negative side input terminal 412 of the voltage conversion circuit 41.

[0070] In this embodiment, the surge voltage caused by static electricity can be bypassed by the bypass circuit 5, thereby reducing the surge voltage.

[0071] (summary) Based on the embodiments described above, the following aspects are disclosed.

[0072] The lighting device (1, 1A~1C) according to the first embodiment includes a circuit section (2). The circuit section (2) includes a rectifier circuit (3), a power conversion circuit (4), an inductance element (L1), and a bypass circuit (5). The rectifier circuit (3) rectifies the AC voltage supplied from the AC power source and generates a pulsating voltage. The power conversion circuit (4) converts the pulsating voltage generated by the rectifier circuit (3) into a DC voltage to be supplied to the light source (6). The inductance element (L1) is electrically connected between the rectifier circuit (3) and the power conversion circuit (4). The bypass circuit (5) bypasses the surge voltage generated in the inductance element (L1).

[0073] With the above configuration, when static electricity is applied to the lighting device (1, 1A~1C), the surge voltage due to the static electricity can be bypassed by the bypass circuit (5). In other words, the effect of static electricity on the lighting device (1, 1A~1C) can be reduced.

[0074] Furthermore, the lighting device (1, 1A~1C) according to the second embodiment further comprises a housing (8) in the first embodiment. The housing (8) is conductive. The housing (8) houses the circuit section (2).

[0075] With the above configuration, noise can be suppressed in the lighting device (1, 1A~1C).

[0076] Furthermore, in the lighting device according to the third embodiment (1, 1A~1C), a surge absorber is not provided that is electrically connected between the housing (8) and the negative electrode circuit between the rectifier circuit (3) and the power conversion circuit (4) as in the second embodiment.

[0077] The above configuration allows for a reduction in the number of components in the lighting device (1, 1A~1C).

[0078] Furthermore, in the lighting device according to the fourth embodiment (1, 1A~1C), the capacitor (C3) electrically connected between the housing (8) and the negative electrode circuit between the rectifier circuit (3) and the power conversion circuit (4) is not provided as in the second or third embodiment.

[0079] The above configuration allows for a reduction in the number of components in the lighting device (1, 1A~1C).

[0080] Furthermore, in the lighting device according to the fifth embodiment (1, 1A~1C), in any one of the second to fourth embodiments, a varistor is not provided that is electrically connected between the housing (8) and the negative electrode circuit between the rectifier circuit (3) and the power conversion circuit (4).

[0081] The above configuration allows for a reduction in the number of components in the lighting device (1, 1A~1C).

[0082] Furthermore, in the lighting device (1, 1A, 1B) according to the sixth embodiment, in any one of the first to fifth embodiments, the bypass circuit (5) is connected in parallel with the inductance element (L1).

[0083] The above configuration makes it possible to suppress surge voltages caused by static electricity.

[0084] Furthermore, in the lighting device (1, 1A) according to the seventh embodiment, the bypass circuit (5) includes a resistor (R1) in the sixth embodiment.

[0085] With the above configuration, the surge voltage can be reduced by the resistor (R1).

[0086] Furthermore, in the lighting device (1A) according to the eighth embodiment, the bypass circuit (5) further includes a capacitor (C4) connected in series with the resistor (R1) in the seventh embodiment.

[0087] With the above configuration, low-frequency noise is suppressed.

[0088] Furthermore, in the lighting device (1B) according to the ninth embodiment, in any one of the sixth to eighth embodiments, the bypass circuit (5) includes a nonlinear resistive element (50). The nonlinear resistive element (50) has the characteristic that its impedance decreases as the applied voltage increases.

[0089] According to the above configuration, noise is suppressed.

[0090] Furthermore, in the lighting device (1C) according to the tenth embodiment, in any one of the first to ninth embodiments, the rectifier circuit (3) is a diode bridge that full-wave rectifies the AC voltage. The rectifier circuit (3) has a positive terminal (33) and a negative terminal (34). The pulsating voltage is the voltage between the positive terminal (33) and the negative terminal (34). The bypass circuit (5) includes a capacitor (C5) electrically connected between the positive terminal (33) and the negative terminal (34) in front of the inductance element (L1).

[0091] The above configuration makes it possible to suppress surge voltages caused by static electricity.

[0092] Configurations other than those in the first embodiment are not essential to the lighting device (1, 1A~1C) and can be omitted as appropriate.

[0093] Furthermore, the lighting fixture (9) according to the 11th embodiment comprises a lighting device (1, 1A to 1C) according to any one of the 1st to 10th embodiments, and an outer casing (90). The lighting device (1, 1A to 1C) comprises a housing (8). The housing (8) is conductive and houses the circuit section (2). The outer casing (90) has a conductive part (91) at the same potential as the housing (8). The outer casing (90) houses the housing (8).

[0094] With the above configuration, noise can be suppressed in the lighting device (1, 1A~1C). [Explanation of Symbols]

[0095] 1. 1A~1C lighting device 2 Circuit section 3 Rectifier circuit 4 Power Conversion Circuit 5 Bypass Circuit 6 light source 8 cabinets 9 Lighting fixtures 33 Positive terminal 34 Negative terminal 50 Nonlinear Resistors 90 Outer shell 91 Conductive part C3 Capacitor C4 Capacitor C5 Capacitor L1 Inductance element R1 resistor

Claims

1. A rectifier circuit that rectifies the AC voltage supplied from an AC power source and generates a pulsating voltage, A power conversion circuit that converts the pulsating voltage generated by the rectifier circuit into a DC voltage to be supplied to the light source, An inductance element electrically connected between the rectifier circuit and the power conversion circuit, A bypass circuit that bypasses the surge voltage generated in the inductance element, It comprises a circuit section having a surge absorber, The aforementioned power conversion circuit is A voltage conversion circuit including a positive input terminal and a negative input terminal, The voltage conversion circuit includes a smoothing capacitor connected between the positive input terminal and the negative input terminal, The surge absorber is connected in parallel with the smoothing capacitor, downstream of the inductance element and the bypass circuit, and upstream of the smoothing capacitor. Lighting device.

2. It further comprises a housing that is conductive and houses the circuit section. The lighting device according to claim 1.

3. The housing does not include a surge absorber electrically connected between the housing and the negative electrode circuit between the rectifier circuit and the power conversion circuit. The lighting device according to claim 2.

4. The housing does not include a capacitor electrically connected between the rectifier circuit and the negative electrode circuit between the rectifier circuit and the power conversion circuit. The lighting device according to claim 2.

5. The enclosure does not include a varistor electrically connected between the rectifier circuit and the negative electrode circuit between the rectifier circuit and the power conversion circuit. The lighting device according to claim 2.

6. The bypass circuit is connected in parallel with the inductance element. The lighting device according to claim 1.

7. The bypass circuit includes a resistor, The lighting device according to claim 6.

8. The bypass circuit further includes a capacitor connected in series with the resistor. The lighting device according to claim 7.

9. The bypass circuit includes a nonlinear resistive element having the characteristic that its impedance decreases as the applied voltage increases. The lighting device according to claim 6.

10. The rectifier circuit is a diode bridge that full-wave rectifies the AC voltage, The rectifier circuit has a positive terminal and a negative terminal, and the pulsating voltage is the voltage between the positive terminal and the negative terminal. The bypass circuit includes a capacitor electrically connected between the positive terminal and the negative terminal in the preceding stage of the inductance element. The lighting device according to claim 1.

11. The lighting device according to claim 2, The system comprises an outer casing that houses the housing and has a conductive part at the same potential as the housing. Lighting fixtures.

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