JP7121922B2 - Power supply circuit and lighting device - Google Patents

Description

TECHNICAL FIELD Embodiments of the present invention relate to power supply circuits and lighting devices.

2. Description of the Related Art A lighting device including a light source such as an LED (Light Emitting Diode) and a power supply circuit that supplies power to the light source to light the light source is known (for example, Patent Document 1).

The power supply circuit includes, for example, a main circuit section and a control section (see Patent Document 2, for example). The main circuit section has a switching element, and converts input power into power corresponding to the light source by switching the switching element. The control unit controls power conversion by the main circuit unit by controlling switching of the switching element. Also, the control section has a control element (control IC) in which various functional parts are housed in one package, and the control element controls the operation of the main circuit section.

In such a control element, a terminal for the ground of the power source of the control element itself (hereinafter referred to as control ground) and a terminal for the ground of the circuit that controls the operation of the main circuit section in the control element (hereinafter referred to as main circuit ground) are used. , are provided, and each terminal is individually wired.

The main circuit ground may fluctuate due to, for example, switching of switching elements. Therefore, if the main circuit ground and the control ground are used as a common terminal, and the ground of the main circuit section and the ground terminal of the control element are connected with one wiring, the control ground will also be affected by fluctuations in the main circuit ground. There is a possibility that it will fluctuate and cause the control element to malfunction.

Therefore, as described above, separate terminals are provided for the control ground and the main circuit ground, and these are wired separately. As a result, it is possible to suppress the fluctuation of the control ground and the associated malfunction of the control element.

However, in the configuration in which the control element is provided with two terminals and each of which is individually wired, the wiring pattern of the substrate becomes complicated and the size of the substrate increases. For example, additional tin-plated jumper wires, ceramic chip jumper wires, etc. are required, making it difficult to reduce the size of the board.

Therefore, in the power supply circuit and the lighting device, it is desired to suppress the malfunction of the control element while suppressing the complication and enlargement of the substrate.

JP 2016-181404 A JP 2016-63618 A

Embodiments of the present invention provide a power supply circuit and a lighting device that can suppress malfunction of a control element while suppressing complication and enlargement of a substrate.

According to an embodiment of the present invention, in a power supply circuit for lighting the light source by supplying power to the light source, a wiring substrate having a base material portion and a wiring pattern provided on the base material portion; a main circuit unit mounted on the wiring board, having a switching element, converting input power into power corresponding to the light source by switching the switching element, and supplying the converted power to the light source; a control unit that has a control element mounted on the wiring board and is packaged, and controls the conversion of power by the main circuit unit by controlling switching of the switching element by the control element; The control element includes an element body, a power supply terminal exposed outside the element body for receiving power supply, a power supply ground of the control element itself exposed outside the element body, and the control element. A ground terminal electrically connected to the ground of the main circuit portion, and the power supply terminal and the ground inside the element body are used as a common terminal, and the ground of the circuit controlling the operation of the main circuit portion in the element body is used as a common terminal. a capacitive element provided between a terminal and a power supply circuit.

According to the embodiments of the present invention, it is possible to provide a power supply circuit and a lighting device capable of suppressing malfunction of a control element while suppressing complication and enlargement of a substrate.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which represents typically the illuminating device which concerns on embodiment. BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which represents typically a part of illuminating device which concerns on embodiment. 3(a) and 3(b) are perspective views schematically showing part of the lighting fixture according to the embodiment. It is an exploded perspective view which expresses typically a part of lighting installation concerning an embodiment. It is a block diagram showing typically the lighting installation concerning an embodiment. 6A and 6B are plan views schematically showing the wiring substrate according to the embodiment. FIG. It is a block diagram which represents typically the lighting installation of reference. It is a block diagram which represents typically the modification of the illuminating device which concerns on embodiment.

Each embodiment will be described below with reference to the drawings.
Note that the drawings are schematic or conceptual, and the relationship between the thickness and width of each portion, the size ratio between portions, and the like are not necessarily the same as the actual ones. Moreover, even when the same parts are shown, the dimensions and ratios may be different depending on the drawing.
In addition, in the present specification and each figure, the same reference numerals are given to the same elements as those described above with respect to the already-appearing figures, and detailed description thereof will be omitted as appropriate.

FIG. 1 is a perspective view schematically showing a lighting device according to an embodiment.
FIG. 2 is a perspective view schematically showing part of the lighting device according to the embodiment.
3(a) and 3(b) are perspective views schematically showing part of the lighting fixture according to the embodiment.
FIG. 4 is an exploded perspective view schematically showing part of the lighting device according to the embodiment.

As shown in FIG. 1 , the lighting device 2 includes a fixture body 10 and a light source module 20 . The lighting device 2 is attached to the indoor ceiling surface with the light source module 20 directed downward. Thereby, the lighting device 2 emits light into the room to illuminate the room. The illumination device 2 has, for example, a long shape extending in one direction. The fixture body 10 and the light source module 20 are similarly elongated. Here, the long shape is, for example, a state in which the length in the longitudinal direction is three times or more as long as the length in the lateral direction (horizontal width).

The fixture body 10 is attached to the ceiling with screws or the like. The fixture main body 10 detachably holds the light source module 20 while being attached to the ceiling. As described above, the fixture main body 10 is used to attach the lighting device 2 to an attachment target such as a ceiling, and is used to hold the light source module 20 . However, the illumination device 2 is not limited to the ceiling, and may be attached to, for example, a wall surface.

Note that FIG. 2 schematically shows the fixture main body 10 with the light source module 20 removed. 3A and 3B schematically show the light source module 20. FIG. FIG. 4 schematically shows an exploded perspective view of the light source module 20. As shown in FIG.

As shown in FIG. 2 , the fixture body 10 includes a housing 11 , a mounting bracket 14 , a power supply circuit 15 and a terminal block 16 . The housing 11 also includes a reflector 12 and an end plate 13 .

The housing 11 has a recess 11a for accommodating part of the light source module 20 . In addition, the housing 11 is provided with a plurality of openings for passing metal fittings (for example, screws) for attaching the lighting device 2 to the ceiling or the like, power cables for supplying power to the power supply circuit 15, and the like.

A metal material such as iron, aluminum, or stainless steel is used for the housing 11 . By using a metal material for the housing 11, the durability of the instrument body 10 can be enhanced. A resin material may be used for the housing 11 .

The reflector 12 reflects the light emitted from the light source 25 inside the light source module 20 . The light reflected by the reflecting plate 12 travels downward of the illumination device 2 . The end plates 13 are provided at both longitudinal ends of the reflector 12 . A concave portion 11 a of the housing 11 is a portion surrounded by the reflector 12 and the end plate 13 .

The mounting bracket 14 is mounted in the recess 11a of the housing 11 by screwing or the like. The mounting bracket 14 is used for holding the light source module 20 . A metal material similar to that of the housing 11 is used for the mounting bracket 14 . A plurality of mounting brackets 14 are provided on the instrument main body 10 in correspondence with the holding members 22 . In this example, two mounting brackets 14 are provided. The number of mounting brackets 14 may be arbitrary. The number of mounting brackets 14 may be one, or three or more.

The power supply circuit 15 converts power supplied from the outside into power corresponding to the light source module 20 and supplies the converted power to the light source module 20 . The light source module 20 turns on the light source 25 according to the power supply from the power supply circuit 15, and emits light. The power supply circuit 15 may be provided separately from the lighting device 2 .

The terminal block 16 is used for electrical connection between an external power source and the power circuit 15 and electrical connection between the power circuit 15 and each light source 25 . The power supply circuit 15 and the terminal block 16 are attached in the concave portion 11a of the housing 11 by screwing or the like. Therefore, the power supply circuit 15 also has an elongated shape extending along the longitudinal direction of the fixture body 10, like the fixture body 10 and the light source module 20. As shown in FIG.

As shown in FIGS. 3 and 4, the light source module 20 includes a cover 21, a holding member 22, side plates 23, a substrate 24, and a light source 25. As shown in FIG. The substrate 24 has a first surface 24a and a second surface 24b opposite the first surface 24a.

The cover 21 covers the light source 25 so that the light from the light source 25 provided on the substrate 24 is emitted. The cover 21 protects the light source 25 from external force, dust, and the like. The cover 21 has optical transparency. The cover 21 is optically transparent to the light emitted by the light source 25 . The cover 21 is, for example, opalescent and light diffusive. Cover 21 may be transparent. A light-transmitting resin material, for example, is used for the cover 21 .

Further, the cover 21 has an insertion hole 21? into which the board 24 is inserted and accommodated. The insertion hole 21 о can be provided based on the shape of the substrate 24 . For example, when the substrate 24 has a rectangular shape, the cover 21 has an insertion hole 21? formed in a rectangular shape. Since the cover 21 accommodates the substrate 24 through the insertion hole 21 о , the substrate 24 having the light source 25 can be provided in the light source module 20 without providing a chassis made of metal or the like for supporting and fixing the substrate 24 . can. Thus, cover 21 directly supports substrate 24 and covers light source 25 . Cover 21 may cover light source 25, for example, by covering substrate 24 attached to another member.

The holding member 22 is attached to the cover 21 . The holding member 22 may be attached to the cover 21 by engagement or the like, or may be attached to the cover 21 by screwing or the like. The holding member 22 is provided corresponding to the mounting bracket 14 of the instrument main body 10 . Therefore, in this example, two holding members 22 corresponding to the two mounting brackets 14 are attached to the cover 21 .

Retaining member 22 engages fitting 14 . The light source module 20 is detachably held in the fixture body 10 by engagement between the mounting bracket 14 and the holding member 22 . Note that the method of holding the light source module 20 is not limited to this, and any method that can be detachably held with respect to the fixture body 10 may be used.

A metal material such as iron, aluminum, or stainless steel is used for the holding member 22, for example. For example, a resin material or the like may be used for the holding member 22 . However, it is preferable to use the metal material as described above for the holding member 22 . Thereby, for example, the durability of the holding member 22 can be improved. Moreover, the holding member 22 is formed from, for example, one sheet of plate material. Thereby, for example, the number of parts can be reduced. For example, the cost of the light source module 20 can be suppressed. For example, when a resin material is used for the holding member 22, the holding member 22 is preferably a single component formed by injection molding or the like.

The side plates 23 are provided at both longitudinal ends of the cover 21 . The shape of the side plate 23 is substantially fan-shaped. The side plate 23 covers and closes the insertion hole 21', for example, and prevents the substrate 24 from coming off from the insertion hole 21'.

A light source 25 is provided on the substrate 24 . A plurality of light sources 25 are provided on the substrate 24, for example. Each light source 25 is arranged side by side on the first surface 24 a of the substrate 24 . The number of light sources 25 may be arbitrary. The number of light sources 25 may be, for example, one.

A light emitting diode (LED) is used for the light source 25, for example. The light source 25 may be an organic light emitting diode (OLED), an inorganic electroluminescence light emitting element, an organic electroluminescence light emitting element, or another electroluminescent light emitting element. The light source 25 may be a light bulb or the like.

FIG. 5 is a block diagram schematically showing the lighting device according to the embodiment.
As shown in FIG. 5 , the power supply circuit 15 of the lighting device 2 includes a wiring board 100 , a main circuit section 102 and a control section 104 .

6A and 6B are plan views schematically showing the wiring substrate according to the embodiment. FIG. As shown in FIGS. 6A and 6B , the wiring board 100 has a base portion 110 and wiring patterns 112 provided on the base portion 110 . The base material portion 110 has a flat plate shape. Moreover, the base material part 110 is elongated. The base material part 110 has, for example, an elongated rectangular shape. The base portion 110 has a first surface 110a and a second surface 110b. The second surface 110b is the surface opposite to the first surface 110a. An insulating material such as glass epoxy is used for the base member 110 . However, the shape of the base portion 110 is not limited to the above, and may be any shape that allows the electronic components of the main circuit portion 102 and the control portion 104 to be mounted.

The wiring pattern 112 is composed of, for example, a plurality of wirings for electrically connecting electronic components mounted on the wiring board 100, pads for surface-mounting the electronic components, and the like. The wiring pattern 112 is provided only on the first surface 110 a of the base material portion 110 . As described above, the wiring board 100 is a single-sided board in which the wiring pattern 112 is provided only on one side of the flat plate-shaped base portion 110 . More specifically, the wiring board 100 is a single-layer single-sided board. However, the wiring board 100 is not limited to a single-sided board. etc.

Also, the wiring board 100 may be a surface mount type board in which electronic components are mounted on the pad portions of the wiring pattern 112, or the leads of the electronic components are inserted into through holes provided in the base material portion 110 and mounted. A through-hole mounting type substrate or a combination of these substrates may be used.

The main circuit section 102 and the control section 104 are mounted on the wiring board 100 . The main circuit section 102 and the control section 104 have a plurality of electronic components. The main circuit unit 102 and the control unit 104 are configured by mounting electronic components on the wiring board 100 and wiring the electronic components with wiring patterns 112 .

The power supply circuit 15 is electrically connected to, for example, an AC power supply PS. The power supply circuit 15 is detachably connected to the AC power supply PS via an outlet or the like, for example. AC power is supplied to the power supply circuit 15 from an AC power supply PS. AC power supply PS is, for example, a commercial power supply. The AC power supply PS may be, for example, a private power generator. The power supplied to the power supply circuit 15 is not limited to AC power, and may be DC power or the like.

Also, the power supply circuit 15 is electrically connected to the light source module 20 . The power supply circuit 15 is detachably connected to the light source module 20 via a connector or the like, for example. In the specification of the present application, "electrically connected" includes not only direct contact connection but also connection via another conductive member or the like.

The main circuit section 102 is electrically connected to the AC power supply PS and the light source module 20 . The main circuit unit 102 converts AC power supplied from the AC power supply PS into DC power corresponding to the light source 25 of the light source module 20 and supplies the DC power to the light source 25 . Thereby, the main circuit section 102 turns on the light source 25 . The control unit 104 controls power conversion by the main circuit unit 102 . In other words, the control unit 104 controls lighting and extinguishing of the light source 25 .

The main circuit section 102 has, for example, a rectifier circuit 120, a power factor correction circuit 122, and a constant current circuit 124. The rectifier circuit 120 rectifies the AC voltage input from the AC power supply PS and converts it into a rectified voltage. A diode bridge in which four rectifying elements are combined is used for the rectifying circuit 120, for example. That is, the rectifier circuit 120 is a full wave rectifier. The rectified voltage is, for example, pulsating voltage.

The rectifier circuit 120 has a pair of input terminals 120a and 120b, a high potential output terminal 120c, and a low potential output terminal 120d. The rectifier circuit 120 converts an AC voltage input through the input terminals 120a and 120b into a rectified voltage, and outputs the rectified voltage from a high potential output terminal 120c and a low potential output terminal 120d. The potential of the low potential output terminal 120d is set to a reference potential (eg ground potential). The potential of the high potential output terminal 120c is set to a potential higher than the potential of the low potential output terminal 120d.

Rectifier circuit 120 may be a half-wave rectifier or the like. The rectified voltage may be full-wave rectified pulsating current or half-wave rectified pulsating current. A Schottky barrier diode, for example, is used for the rectifier circuit 120 . Thereby, for example, good responsiveness can be obtained.

Power factor correction circuit 122 is electrically connected to the output side of rectifier circuit 120 . The power factor correction circuit 122 suppresses the generation of harmonics of integral multiples of the power supply frequency in the rectified voltage. Thereby, the power factor correction circuit 122 improves the power factor of the rectified voltage.

Power factor correction circuit 122 includes, for example, switching element 130 , inductor 131 , diode 132 , and smoothing capacitor 133 . The switching element 130 has electrodes 130a to 130c. One end of the inductor 131 is electrically connected to the high potential output terminal 120c. The other end of inductor 131 is electrically connected to electrode 130a. The electrode 130b is electrically connected to the low potential output terminal 120d.

The anode of diode 132 is electrically connected to electrode 130a. A cathode of the diode 132 is electrically connected to one end of the smoothing capacitor 133 . The other end of the smoothing capacitor 133 is electrically connected to the low potential output terminal 120d. That is, in this example, power factor correction circuit 122 is a boost chopper circuit. The power factor correction circuit 122 is not limited to this, and may be any circuit capable of improving the power factor of the rectified voltage.

Electrode 130 c is electrically connected to control unit 104 . The electrode 130c is a so-called control electrode. The switching element 130 switches according to a signal from the control section 104 . The power factor correction circuit 122 improves the power factor by, for example, switching the switching element 130 to bring the input current closer to a sine wave.

The switching element 130 is, for example, an n-channel FET. For example, electrode 130a is the drain, electrode 130b is the source, and electrode 130c is the gate. The switching element 130 may be, for example, a p-channel FET or a bipolar transistor.

The smoothing capacitor 133 converts the pulsating voltage into a DC voltage by smoothing the pulsating voltage after the power factor improvement.

Power factor correction circuit 122 further includes inductor 134 . Inductor 134 is magnetically coupled with inductor 131 . Inductor 134 is electrically connected to control unit 104 . Inductor 134 detects the rectified voltage input to power factor correction circuit 122 and inputs the detection result to control section 104 .

For example, if the power supplied to the power supply circuit 15 is DC power, the rectifier circuit 120 and the power factor correction circuit 122 may be omitted. Thus, the rectifier circuit 120 and the power factor correction circuit 122 are provided as required and can be omitted.

The constant current circuit 124 controls the output current so that the direct current supplied to the connected light source module 20 is constant. The constant current circuit 124 has a switching element 140, an inductor 141, and a diode 142, for example. The switching element 140 has electrodes 140a-140c. The electrode 140a is electrically connected to one end of the smoothing capacitor 133 on the high potential side. Electrode 140 b is connected to one end of inductor 141 . The other end of the inductor 141 is electrically connected to the high potential side terminal of the light source module 20 .

A cathode of the diode 142 is electrically connected to the electrode 140 b of the switching element 140 . The anode of the diode 142 is electrically connected to the low potential terminal of the light source module 20 and the low potential output terminal 120d.

Electrode 140 c is electrically connected to control unit 104 . The switching element 140 switches according to a signal from the control section 104 . Switching element 140 controls the current flowing through inductor 141 . The constant current circuit 124 controls the direct current supplied to the light source module 20 to be constant by switching the switching element 140 .

In this example, constant current circuit 124 is a so-called step-down chopper circuit. The constant current circuit 124 reduces the voltage value of the DC voltage boosted by the power factor correction circuit 122 to a voltage value corresponding to the light source module 20 . Note that the configuration of the constant current circuit 124 is not limited to the above, and may be any configuration that can supply a substantially constant current to the light source module 20 .

In this way, the main circuit section 102 has switching elements 130 and 140, and by switching the switching elements 130 and 140, the input power is converted into power corresponding to the light source 25 of the light source module 20, and the converted power is Power is supplied to the light source 25 of the light source module 20 . However, the configuration of the main circuit section 102 is not limited to the above, and may be any configuration that can supply appropriate power to the light source 25 by switching the switching elements.

The constant current circuit 124 further has a detector 143, for example. The detection unit 143 is provided on the downstream side of the light source module 20 and detects the current value of the direct current flowing through the light source module 20 . The detection unit 143 is electrically connected to the control unit 104 and inputs detection results to the control unit 104 .

The detection unit 143 is provided, for example, between the low voltage side terminal of the light source module 20 and the low potential output terminal 120d. The detection unit 143 is, for example, a detection resistor for detecting the current value of direct current. The detector 143 may be, for example, a clamp-type ammeter that measures changes in magnetic flux. Note that the detection unit 143 may be configured to detect the voltage of the light source module 20 . The detection unit 143 may be configured to detect both current and voltage.

The controller 104 has a packaged control element 150 . The control element 150 is, for example, a control IC (Integrated Circuit). Control element 150 controls the operation of power factor correction circuit 122 and constant current circuit 124 .

Control element 150 is electrically connected to electrode 130 c of switching element 130 and inductor 134 . For example, the control element 150 detects a zero crossing of the rectified voltage based on the detection result of the inductor 134, and switches the switching element 130 based on the zero crossing detection result, thereby controlling the operation of the power factor correction circuit 122. .

The control element 150 is electrically connected to the electrode 140 c of the switching element 140 and the detection section 143 . For example, the control element 150 brings the switching element 140 into a conducting state when the current flowing through the light source module 20 is less than a predetermined value, and brings the switching element 140 into a non-conducting state when the current flowing through the light source module 20 is greater than or equal to a predetermined value. and Thereby, the control element 150 causes the current flowing through the light source module 20 to be substantially constant.

Thus, the control unit 104 controls the conversion of power by the main circuit unit 102 by controlling the switching of the switching elements 130 and 140 by the control element 150 .

The control element 150 has an element body 151 , a power terminal 152 , a ground terminal 153 and a capacitive element 154 . The element body 151 is, for example, a portion obtained by molding a semiconductor chip with resin, ceramics, or the like.

The power terminal 152 and the ground terminal 153 are exposed outside the element body 151 . The power terminal 152 and the ground terminal 153 are so-called leads, pads, and the like. The power terminal 152 is a terminal for receiving power supply of the control element 150 itself. The ground terminal 153 is electrically connected to the ground of the main circuit section 102 . In this example, the ground of the main circuit section 102 is, for example, the portion electrically connected to the electrode 130b of the switching element 130 or the low potential output terminal 120d. That is, the ground terminal 153 is electrically connected to the electrode 130b of the switching element 130 or the low potential output terminal 120d.

The power supply circuit 15 further comprises, for example, a power supply section 106 that supplies power to the control element 150 . The power supply section 106 has, for example, an inductor 160 and a charge storage element 162 . Inductor 160 is magnetically coupled with inductor 141 . Inductor 160 is also electrically connected to charge storage element 162 . As a result, inductor 160 generates an electromotive force according to the current flowing through inductor 141, and charge storage element 162 is charged by this electromotive force.

The wiring pattern 112 has a power supply line 112a and a ground line 112b. The power line 112 a is electrically connected to the power terminal 152 . The power line 112a electrically connects the power terminal 152 and the charge storage element 162, for example. Thereby, the voltage of the charge storage element 162 is supplied to the power supply terminal 152 as the power supply voltage of the control element 150 .

Ground line 112 b is electrically connected to ground terminal 153 . The ground line 112b electrically connects the ground terminal 153 and the electrode 130b (low potential output terminal 120d) of the switching element 130, for example. One end of the charge storage element 162 is electrically connected to the power supply line 112a, and the other end of the charge storage element 162 is electrically connected to the ground line 112b. Thereby, power is supplied from the power supply unit 106 to the control element 150 via the power supply line 112a and the ground line 112b.

The capacitive element 154 is provided inside the element body 151 . The capacitive element 154 is manufactured at the same time as an internal circuit, for example, in a semiconductor process of a semiconductor chip (not shown). For example, the capacitive element 154 may be provided separately from the semiconductor chip and may be provided inside the element main body 151 by being molded with resin or the like together with the semiconductor chip.

The capacitive element 154 is provided between the power terminal 152 and the ground terminal 153 inside the element body 151 . That is, one end of the capacitive element 154 is electrically connected to the power supply terminal 152 and the other end of the capacitive element 154 is electrically connected to the ground terminal 153 . Capacitive element 154 is, for example, a capacitor. Capacitive element 154 is a so-called bypass capacitor.

The capacitance of the capacitive element 154 is, for example, 0.01 μF or more and 0.2 μF or less. Providing the capacitive element 154 between the power supply terminal 152 and the ground terminal 153 inside the element main body 151, in other words, sets the capacitance between the power supply terminal 152 and the ground terminal 153 to 0.01 μF or more. It is to be. Therefore, for example, when the capacitance between the power supply terminal 152 and the ground terminal 153 is measured and the capacitance is 0.01 μF or more, the power supply terminal 152 and the ground terminal 153 inside the element main body 151 It can be determined that the capacitive element 154 is provided between.

FIG. 7 is a block diagram schematically showing a reference lighting device.
It should be noted that the same reference numerals are given to the elements that are substantially the same in terms of function and configuration as those of the above-described embodiment, and detailed description thereof will be omitted.
As shown in FIG. 7, in the power supply circuit 15x of the reference lighting device 2x, the control element 150x has a control ground terminal 153a and a main circuit ground terminal 153b. is electrically connected to the ground of the main circuit section 102 . The wiring pattern 112x further has a ground line 112c that electrically connects the terminal 153b and the ground of the main circuit section 102 .

Also, in the power supply circuit 15 x , the control element 150 does not have the capacitive element 154 . A capacitive element 155 is provided outside the element body 151 between the power supply line 112a and the ground line 112b. One end of the capacitor 155 is electrically connected to the power supply line 112a, and the other end of the capacitor 155 is electrically connected to the ground line 112b. Capacitive element 155 is a so-called external bypass capacitor.

Thus, separate terminals 153a and 153b are provided for the control ground and the main circuit ground, and an external capacitive element 155 is provided. As a result, it is possible to suppress the fluctuation of the control ground and the associated malfunction of the control element.

On the other hand, in the configuration in which two terminals 153a and 153b are provided in the control element 150 and each is wired separately, the wiring pattern 112x of the wiring board 100x becomes complicated and the wiring board 100x becomes large. For example, a tin-plated jumper wire, a ceramic chip jumper wire, and the like are additionally required, which makes it difficult to miniaturize the wiring board 100x.

In contrast, in the power supply circuit 15 according to the present embodiment, only one ground terminal 153 is provided, and only one ground line 112b is used to connect the ground of the main circuit section 102 and the control element 150 . That is, the control element 150 has a common terminal for the control ground and the main circuit ground.

As a result, it is possible to prevent the wiring pattern 112 of the wiring board 100 from becoming more complicated and the wiring board 100 from becoming larger than the reference power supply circuit 15x. For example, in a long single-sided substrate as shown in FIG. 6, the number of wirings can be reduced, and the degree of freedom in designing the wiring pattern 112 can be increased. For example, the width in the width direction of the wiring board 100, which is a long single-sided board, can be made smaller.

In the power supply circuit 15 according to this embodiment, a capacitive element 154 is provided between the power supply terminal 152 and the ground terminal 153 inside the element body 151 . As a result, even when the control ground and the main circuit ground are used as a common terminal, fluctuations in the control ground can be suppressed, and malfunction of the control element 150 can be suppressed. Therefore, in the power supply circuit 15 and the lighting device 2 according to the present embodiment, it is possible to suppress the malfunction of the control element 150 while suppressing the wiring board 100 from becoming complicated and increasing in size.

FIG. 8 is a block diagram schematically showing a modification of the lighting device according to the embodiment;
As shown in FIG. 8, in the power supply circuit 15a of the lighting device 2a, the control unit 104a further includes another capacitive element 155 provided outside the element body 151 between the power supply line 112a and the ground line 112b. is doing.

Thus, the power supply circuit 15a may further have an external capacitive element 155 . This makes it possible to more appropriately suppress fluctuations in the control ground. On the other hand, when the capacitive element 155 is omitted, complication of the wiring pattern 112 can be further suppressed. The complication and enlargement of the wiring board 100 can be suppressed more reliably.

While several embodiments and examples of the invention have been described, these embodiments or examples are provided by way of example and are not intended to limit the scope of the invention. These novel embodiments or examples can be embodied in various other forms, and various omissions, replacements, and modifications can be made without departing from the spirit of the invention. These embodiments, examples, and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 2, 2a, 2x... Lighting apparatus 10... Fixture main body 11... Housing 12... Reflector 13... End plate 14... Mounting bracket 15, 15a, 15x... Power supply circuit 16... Terminal block 20... Light source module 21 Cover 22 Holding member 23 Side plate 24 Board 25 Light source 100, 100x Wiring board 102 Main circuit section 104, 104a Control section 106 Power supply section 110 Base material portion 112 Wiring pattern 112a Power supply line 112b, 112c Ground line 112x Wiring pattern 120 Rectifier circuit 122 Power factor improvement circuit 124 Constant current circuit 130 Switching element DESCRIPTION OF SYMBOLS 131... Inductor 132... Diode 133... Smoothing capacitor 134... Inductor 140... Switching element 141... Inductor 142... Diode 143... Detection part 150... Control element 150x... Control element 151... Element body, 152 power supply terminal 153 ground terminal 154 capacitive element 155 capacitive element 160 inductor 162 charge storage element

Claims (4)

In a power supply circuit for lighting the light source by supplying power to the light source,
a wiring board having a base material portion and a wiring pattern provided on the base material portion;
a main circuit unit mounted on the wiring board, having a switching element, converting input power into power corresponding to the light source by switching the switching element, and supplying the converted power to the light source;
a control unit having a control element mounted on the wiring board and packaged, and controlling the conversion of power by the main circuit unit by controlling switching of the switching element by the control element;
with
The control element is
an element body;
a power terminal exposed to the outside of the element body for receiving power supply;
The power supply ground of the control element itself and the circuit ground for controlling the operation of the main circuit section in the control element are exposed to the outside of the element body, and the ground of the main circuit section is used as a common terminal. an electrically connected ground terminal;
a capacitive element provided between the power supply terminal and the ground terminal inside the element body;
A power supply circuit having The wiring pattern has a power line electrically connected to the power terminal and a ground line electrically connected to the ground terminal,
2. The power supply circuit according to claim 1, wherein said control section further includes another capacitive element provided between said power supply line and said ground line outside said element body. 3. The power supply circuit according to claim 1, wherein the wiring board is a single-sided board in which the wiring pattern is provided only on one side of the flat base material portion. a light source;
The power supply circuit according to any one of claims 1 to 3, which turns on the light source by supplying power to the light source;
A lighting device with

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