JP2015162388A - Power supply device and lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device and a lighting device that can reduce high frequency noise radiated from a board.SOLUTION: A power supply device 19 has a board 12, a first power supply circuit 13 which is provided on the board 12 and converts AC voltage to DC voltage, and three or more second power supply circuits 20 each of which is provided on the board 12 in connection with each of plural light sources 30, converts the DC voltage converted by the first power supply circuit 13 to a predetermined voltage, and supplies the converted voltage to the corresponding light source 30. The respective second power supply circuits 20 are connected to different connection positions on a power supply wire 120 extending from the first power supply circuit 13 on the board 12 in parallel. When the respective second power supply circuits 20 are assigned in the length-increasing order along the power supply wire from the first power supply circuit 13 to the connection position of each second power supply circuit 20, at least one capacitor 40 is provided between a ground wire 121 on the board 12 and a position on the power supply wire 120 which is farther away from the first power supply circuit 13 than the connection position of the second second power supply circuit 20.

Description

  Embodiments described herein relate generally to a power supply device and a lighting device.

  2. Description of the Related Art A power supply device having a rectifier circuit that converts an AC voltage into a DC voltage and a voltage conversion circuit that converts the converted DC voltage into a predetermined voltage and supplies the voltage to a load such as an LED (Light Emitting Diode) is known. . In such a power supply device, when there are a plurality of loads that are individually controlled, a voltage conversion circuit is provided for each load that is individually controlled.

  By the way, there are cases where the shape of the board on which the electrical components that make up the rectifier circuit, voltage conversion circuit, etc. are placed is limited due to design restrictions, which restricts the placement of the electrical parts on the board. May be. For example, in the case of a long and narrow substrate, there are cases where electrical components have to be arranged in the longitudinal direction of the substrate. If the electrical components are arranged in a predetermined direction, the wiring on the substrate connecting the electrical components may be long. As the wiring becomes longer, the inductance component of the wiring increases, and the high frequency noise generated by resonance with the capacitance component of the electrical component increases.

JP 2013-229234 A

  The problem to be solved by the present invention is to reduce high frequency noise.

  The power supply device according to the embodiment is provided on the substrate corresponding to each of a substrate, a first power supply circuit that is provided on the substrate and converts an AC voltage into a DC voltage, and a plurality of loads. Three or more second power supply circuits that convert the DC voltage converted by the first power supply circuit into a predetermined voltage and supply it to a corresponding load, each of the second power supply circuits comprising: The power supplies connected in parallel to different connection positions on the power supply wiring extending on the substrate from the first power supply circuit, and from the first power supply circuit to the connection positions of the respective second power supply circuits. When an order is assigned to each of the second power supply circuits in order of decreasing length along the wiring, the length from the first power supply circuit reaches the connection position of the second second power supply circuit. Position on the power supply wiring longer than the length of , Between the ground wiring on the substrate, at least one capacitor is provided.

  According to the present invention, it can be expected to reduce radiated noise.

FIG. 1 is a perspective view illustrating an example of a lighting device according to the embodiment. FIG. 2 is a diagram illustrating an example of a power supply device. FIG. 3 is a diagram illustrating an example of a circuit configuration of the illumination device according to the first embodiment. FIG. 4 is a diagram illustrating an example of the configuration of each second power supply circuit. FIG. 5 is a diagram illustrating an example of a circuit configuration of the illumination device according to the second embodiment. FIG. 6 is a diagram for explaining an example of the position of the capacitor when n = 3. FIG. 7 is a diagram for explaining an example of the position of the capacitor when n = 6.

  A power supply device according to an embodiment described below is provided on a substrate, a first power supply circuit that is provided on the substrate, converts an AC voltage into a DC voltage, and a plurality of loads. Three or more second power supply circuits that convert the DC voltage converted by the first power supply circuit into a predetermined voltage and supply it to a corresponding load. Each of the second power supply circuits is connected in parallel to different connection positions on the power supply wiring extending on the substrate from the first power supply circuit, and from the first power supply circuit to the connection position of each of the second power supply circuits. When the order is assigned to each of the second power supply circuits in the order of the shortest length along the power supply wiring, the length from the first power supply circuit reaches the connection position of the second second power supply circuit. At least one capacitor is provided between a position on the power supply wiring longer than the length of the power supply wiring and the ground wiring on the substrate. According to such a power supply device, the path of the high frequency noise generated by the second power supply circuit disposed on the substrate away from the capacitor from the first power supply circuit is more than the path to the first power supply circuit. Can also be shortened to a short capacitor path. Thereby, the inductance component of the wiring which comprises the path | route of a high frequency noise can be made small, and it can anticipate reducing a high frequency noise.

  Further, in the power supply device according to the embodiment described below, in each of the second power supply circuits, the capacitor is along the wiring from the second power supply circuit to the first power supply circuit via the power supply wiring. Of the length and the length along the wiring to the capacitor via the power wiring, the shorter one is preferably provided between the position on the power wiring where the length is equal to or less than a predetermined length and the ground wiring. Thereby, the length of the wiring which comprises the path | route of a high frequency noise can be made into below predetermined length, and the inductance component contained in wiring can be made small. Thereby, it can be expected that high frequency noise is reduced to a predetermined value or less.

  In the power supply device according to the embodiment described below, the capacitor has a k-th second power supply line on the power supply wiring when the number of second power supply circuits is n (n is an integer of 3 or more). When at least one is provided between the position on the power supply wiring between the connection position of the power supply circuit and the connection position of the (k + 1) th second power supply circuit and the ground wiring, and n is an even number, The value of k is n / 2, and when n is an odd number, the value of k may be (n + 1) / 2. Thereby, in the plurality of second power supply circuits, the maximum value of the length of the power supply wiring and the ground wiring to the first power supply circuit or the capacitor can be suppressed low. This can be expected to reduce high frequency noise.

  In the power supply device according to the embodiment described below, six second power supply circuits are provided on the substrate, and the capacitor is connected to the connection position of the third second power supply circuit on the power supply wiring. At least one may be provided between a position on the power supply wiring between the connection position of the fourth second power supply circuit and the ground wiring. Thereby, in the six second power supply circuits, the maximum value of the wiring on the substrate up to the first power supply circuit or the capacitor can be kept low. This can be expected to reduce high frequency noise.

  Further, in the power supply device according to the embodiment described below, each second power supply circuit supplies the energy from the first power supply circuit to the inductor by turning on the inductor and the diode, and turns off the inductor. And a switching element that cuts off the supply of energy from the first power supply circuit to the inductor and releases the energy stored in the inductor via the diode, and the power supply device turns the switching element on and off A control circuit that supplies a control signal to be supplied to the switching element included in each second power supply circuit may be further included.

  Further, in the power supply device according to the embodiment described below, the load may be a semiconductor light emitting element. Moreover, the illuminating device which concerns on embodiment described below may comprise said power supply device and the light emitting element as load.

  Hereinafter, a power supply device and an illumination device according to an embodiment will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the structure which has the same function in embodiment, and the overlapping description is abbreviate | omitted. Moreover, the power supply device and the illumination device described in the following embodiments are merely examples, and do not limit the present invention. Further, the following embodiments may be appropriately combined within a consistent range.

(First embodiment)
[Configuration of Lighting Device 1]
FIG. 1 is a perspective view illustrating an example of a lighting device 1 according to the embodiment. The illumination device 1 is, for example, a ceiling light, and includes a device main body 10 and a globe 11 that covers the entire lower surface of the device main body 10. A substrate on which a light source is arranged is provided on the lower surface of the apparatus body 10. The light sources are divided into a plurality of (for example, six) groups, and lighting, extinguishing, and dimming can be controlled independently for each group.

  A power supply device for supplying power to the light source is provided on the back side of the substrate on which the light source is provided, and is connected to the substrate on which the light source is arranged by a cable or the like. The light source emits light according to the power supplied via the cable. The globe 11 is formed of a light-transmitting resin material or the like, and transmits light emitted from the light source. The globe 11 may be transparent, for example, and may have light diffusibility.

  The lighting device 1 has a connector provided on the ceiling and electrically connected to, for example, a substantially cylindrical hook ceiling. The lighting device 1 is fixed to the ceiling with the globe 11 facing downward by the connector being hooked and fitted into the ceiling. The hook ceiling is connected to a power line of a commercial AC power source drawn from behind the ceiling.

  FIG. 2 is a diagram illustrating an example of the power supply device 19. The power supply device 19 includes a substrate 12, a first power supply circuit 13, a control circuit 14, and three or more second power supply circuits 20-1 to 20-n. In the present embodiment, the power supply device 19 includes, for example, six second power supply circuits 20. In the center of the substrate 12, an opening is provided for placing a connector that fits into the hook ceiling. The board | substrate 12 is provided in the illuminating device 1 so that the circumference | surroundings of the connector fitted in hooking sealing may be enclosed.

  On the substrate 12, for example, as shown in FIG. 2, the first power supply circuit 13 that converts the voltage of the commercial AC power supply into a DC voltage, and the DC voltage converted by the first power supply circuit 13 is converted into a desired voltage. A plurality of second power supply circuits 20-1 to 20-n supplied to the light source and a control circuit 14 for controlling each of the second power supply circuits 20-1 to 20-n are provided. Hereinafter, the second power supply circuits 20-1 to 20-n are collectively referred to as “second power supply circuit 20” without being distinguished from each other.

  The first power supply circuit 13 receives the AC voltage of the commercial AC power supply from the hook ceiling through the connector, and converts the received AC voltage into a DC voltage. Each second power supply circuit 20 converts the voltage converted into direct current by the first power supply circuit 13 into a direct current voltage having a desired voltage, and supplies the converted direct current voltage to a corresponding light source via a cable. . The light emitting elements included in each light source emit light according to a current based on the supplied DC voltage.

[Circuit Configuration of Lighting Device 1]
FIG. 3 is a diagram illustrating an example of a circuit configuration of the illumination device 1 according to the first embodiment. The input terminal of the first power supply circuit 13 is connected to the commercial AC power supply 15 via the connector, the hook ceiling, and the switch 16 in a state where the lighting device 1 is fixed to the ceiling. The output terminal P ₀ of the first power supply circuit 13 is connected to each of the second power supply circuits 20-1 to 20 -n via the power supply wiring 120. The first power supply circuit 13 and each of the second power supply circuits 20-1 to 20-n are grounded via a ground wiring 121.

  Each of the second power supply circuits 20-1 to 20-n is provided in correspondence with each of the light sources 30-1 to 30-n. Hereinafter, the light sources 30-1 to 30-n are collectively referred to as “light source 30” without being distinguished from each other.

Each of the second power supply circuits 20 is connected in parallel to different positions on the power supply wiring 120 extending from the first power supply circuit 13 on the substrate 12. In the example shown in FIG. 3, the second power supply circuit 20-1, for example, in the connecting position P ₁ is connected to the power supply line 120, the second power supply circuit 20-2, for example different from the connecting position P ₁ It is connected to the power supply wiring 120 at the connection position P ₂ that is a position on the power supply wiring 120.

  FIG. 4 is a diagram illustrating an example of the configuration of each second power supply circuit 20. Each second power supply circuit 20 includes a diode 21, a capacitor 22, an inductor 23, a switching element 24, and a resistor 25, for example, as shown in FIG. 4. In the present embodiment, the switching element 24 is, for example, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor). As another example, the switching element 24 may be a bipolar transistor, a junction FET, or the like.

  The cathode of the diode 21 is connected to the power supply wiring 120. The anode of the diode 21 is connected to a node between the inductor 23 and the switching element 24. One end of the capacitor 22 is connected to the power supply wiring 120, and the other end is connected to a node between the inductor 23 and the light source 30.

  The inductor 23 has one end connected to the light source 30 and the other end connected to the drain terminal of the switching element 24. The switching element 24 has a drain terminal connected to the other end of the inductor 23, a gate terminal connected to the control circuit 14, and a source terminal grounded via a resistor 25.

  Each light source 30 has a plurality of light emitting elements 31 connected in series. One end of each light source 30 is connected to the power supply wiring 120. The other end of each light source 30 is connected to one end of an inductor 23.

  The light emitting element 31 in the present embodiment is an example of a load that operates based on the voltage and current supplied from the second power supply circuit 20. In the present embodiment, the light emitting element 31 is a semiconductor light emitting element such as an LED. As another example, the light emitting element 31 may be an organic light emitting diode, an inorganic electro-luminescence light emitting element, or other electroluminescent light emitting element. .

  When the switch 16 is closed, the first power supply circuit 13 converts the voltage of the commercial AC power received via the switch 16 into a DC voltage and supplies the DC voltage to each second power supply circuit 20. Each second power supply circuit 20 steps down the DC voltage supplied from the first power supply circuit 13 to a desired voltage and supplies it to the corresponding light source 30.

  The control circuit 14 supplies a control signal for controlling the on / off operation of the switching element 24 to each second power supply circuit 20. Specifically, the control circuit 14 controls the switching element 24 to be turned on by supplying a control signal for controlling the gate-source voltage to a high level to the switching element 24 of each second power supply circuit 20. Then, the current from the first power supply circuit 13 is passed through the light source 30 and the inductor 23. By controlling the switching element 24 from OFF to ON, the current flowing through the inductor 23 increases and energy is stored in the inductor 23.

  Then, the control circuit 14 supplies the control signal for controlling the voltage between the gate and the source to the low level to the switching element 24 of each second power supply circuit 20, thereby controlling the switching element 24 to be turned off. Current supply from the power supply circuit 13 to the light source 30 and the inductor 23 is cut off. By controlling the switching element 24 from on to off, the current flowing through the inductor 23 is supplied to the light source 30 via the diode 21, the current flowing through the inductor 23 is reduced, and the energy stored in the inductor 23 is released. The

  Thus, each second power supply circuit 20 operates as a step-down chopper circuit by turning on and off the switching element 24 by the control signal from the control circuit 14. The control circuit 14 operates each second power supply circuit 20 in, for example, a current discontinuous mode.

Here, the order is assigned to each of the second power supply circuits 20 in order of decreasing length along the power supply wiring 120 from the first power supply circuit 13 to the connection position of each of the second power supply circuits 20. In the example shown in FIG. 3, the length along the power supply wiring 120 from the output terminal P _{0 of} the first power supply circuit 13 to the connection positions P _{1 to} Pn of the respective second power supply circuits 20-1 to 20 _-n is set. Considering this, the second power supply circuit 20-1 is the first, the second power supply circuit 20-2 is the second, and the second power supply circuit 20-n is the nth.

In the power supply device 19 according to the present embodiment, the length along the power supply wiring 120 from the first power supply circuit 13 is longer than the length to the connection position P ₂ of the second second power supply circuit 20. At least one capacitor 40 is provided between the upper position and the ground wiring 121.

In the example shown in FIG. 3, the second second and the connecting position P ₂ of the power supply circuit 20-2, the third power supply wiring 120 on between the connecting position P ₃ of the second power supply circuit 20-3 One capacitor 40 is provided at the position _Pc . One end of the capacitor 40 is connected to the position P _c on the power supply wiring 120, and the other end is connected to the ground wiring 121.

In the power supply device 19 in the present embodiment, the length along the power supply wiring 120 from the first power supply circuit 13 is longer than the length to the connection position P2 of the _{second second} power supply circuit 20-2. Since the capacitor 40 only needs to be provided at a position on the long power supply wiring 120, for example, the connection position P _n− of the (n−1) th second power supply circuit 20-(n−1) for n of 4 or more. _The capacitor 40 may be provided at a position on the power supply wiring 120 between ₁ and the connection position P _n of the _n -th second power supply circuit 20-n.

Thus, the length along the power supply wiring 120 from the first power supply circuit 13, the position of the long power wiring 120 than the length of the connection to the position P ₂ of the second of the second power supply circuit 20-2 By providing at least one capacitor 40 between P _c and the ground wiring 121, the second power supply circuit 20 arranged on the substrate 12 away from the capacitor 40 from the first power supply circuit 13. It is possible to shorten the path of high-frequency noise generated by −3 to n.

For example, when the capacitor 40 is not provided, as shown in FIG. 3, the path of high-frequency noise is the second power supply circuit 20-n generates becomes R _1. In contrast, by the capacitor 40 is provided, the path of high-frequency noise is the second power supply circuit 20-n generates is shortened to a short R ₂ than R _1. Also in the second power supply circuits 20-1 to n-1, the length along the wiring to the capacitor 40 through the power supply wiring 120 is the wiring to the first power supply circuit 13 through the power supply wiring 120. If the length of the second power supply circuit 20 is shorter, the path of the high-frequency noise generated by the second power supply circuit 20 is shortened by providing the capacitor 40.

  As a result, the inductance components of the power supply wiring 120 and the ground wiring 121 included in the high-frequency noise path can be reduced. For example, the inductance components of the power supply wiring 120 and the ground wiring 121 and the parasitic capacitance of the second power supply circuit 20 can be reduced. It can be expected that high frequency noise generated due to resonance with (for example, parasitic capacitance of the diode 21) is reduced.

A position P _c on the power supply wiring 120 having a length along the power supply wiring 120 from the first power supply circuit 13 longer than the length to the connection position P ₂ of the second second power supply circuit 20; A plurality of capacitors may be provided between the ground wiring 121. In this case, if the frequency band of the high frequency noise to be reduced is wide, a plurality of different constant capacitors 40 having capacitive characteristics in the frequency band may be provided.

  In addition, the capacitor 40 has, for each second power supply circuit 20, a length along the wiring from the second power supply circuit 20 to the first power supply circuit 13 via the power supply wiring 120, and the power supply wiring 120. Among the lengths along the wiring to the capacitor 40, the shorter one is preferably provided between the position on the power supply wiring 120 where the predetermined length is equal to or shorter than the predetermined length and the ground wiring 121.

  Here, the predetermined length is, for example, a high frequency generated by resonance between an inductance component included in the wiring of that length and a parasitic capacitance (eg, parasitic capacitance of the diode 21) included in the second power supply circuit 20. The length of the wiring where the noise is less than or equal to a predetermined magnitude. Thereby, it can be expected that high-frequency noise generated from the lighting device 1 is reduced to a predetermined value or less.

  The first embodiment has been described above.

  As is clear from the above description, according to the illumination device 1 of the present embodiment, it can be expected to reduce high-frequency noise.

(Second Embodiment)
FIG. 5 is a diagram illustrating an example of a circuit configuration of the illumination device 1 according to the second embodiment. For example, as illustrated in FIG. 5, the lighting device 1 according to the present embodiment includes the kth second power supply circuit 20 in n (n is an integer of 3 or more) second power supply circuits 20-1 to 20-n. a connection position P _k of -k, (k + 1) th to the position P _c on the power supply lines 120 between the connecting position P _{k + 1} of the second power supply circuit 20- (k + 1), at least one capacitor 40 Is provided. One end of the capacitor 40 is connected to the position P _c on the power supply wiring 120, and the other end is connected to the ground wiring 121. Here, when n is an even number, the value of k is, for example, n / 2. When n is an odd number, the value of k is (n + 1) / 2, for example.

  Thereby, in the plurality of second power supply circuits 20, the maximum values of the lengths of the power supply wiring 120 and the ground wiring 121 with respect to the high-frequency signal to the first power supply circuit 13 or the capacitor 40 can be kept low. As a result, the maximum value of the parasitic inductance included in the wiring can be reduced, and high frequency noise generated from the lighting device 1 can be expected to be reduced.

FIG. 6 is a diagram for explaining an example of the position of the capacitor 40 when n = 3. When n = 3, since n is an odd number, the value of k is (3 + 1) / 2 = 2. Thus, in the example of FIG. 6, the second second and the connecting position P ₂ of the power supply circuit 20-2, the third power supply wiring 120 on between the connecting position P ₃ of the second power supply circuit 20-3 At least one capacitor 40 is provided between the position P _c and the ground wiring 121.

FIG. 7 is a diagram for explaining an example of the position of the capacitor 40 when n = 6. When n = 6, since n is an even number, the value of k is 6/2 = 3. Thus, in the example of FIG. 7, the third second and the connecting position P ₃ of the power supply circuit 20-3, the fourth of the second power supply wiring 120 on between the connecting position P ₄ of the power supply circuit 20-4 At least one capacitor 40 is provided between the position P _c and the ground wiring 121.

  The second embodiment has been described above.

[Modification]
In addition, this invention is not limited to above-described embodiment, Many deformation | transformation are possible within the range of the summary.

For example, in the first and second embodiments described above, the length from the first power supply circuit 13, the second second long power line than the length of the connection to the position P ₂ of the power supply circuit 20-2 the position P _c on 120, between the ground wire 121, at least one capacitor 40 is provided, the position P _c where the capacitor 40 is provided is not limited to the above power supply line 120. For example, in the second and second second power supply circuits 20, the connection position P of the second power supply circuit 20, the position on the wiring from the connection position P to the second power supply circuit 20, and the ground wiring 121. Between the two, at least one capacitor 40 may be provided. Alternatively, at least one capacitor 40 is provided between the high potential side in the second power supply circuit 20 (for example, a wiring connecting the cathode of the diode 21 and the capacitor 22) and the ground wiring 121. Also good.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

12 substrate 120 power wiring 121 ground wiring 13 first power circuit 14 control circuit 19 power supply device 20 second power circuit 30 light source 40 capacitor

Claims (6)

A substrate;
A first power supply circuit provided on the substrate for converting an alternating voltage into a direct voltage;
The DC voltage provided on the substrate corresponding to each of a plurality of loads and converted by the first power supply circuit is converted into a predetermined voltage and supplied to the corresponding loads. Power supply circuit;
Comprising
Each of the second power supply circuits is
Are connected in parallel to different connection positions on a power supply wiring extending on the substrate from the first power supply circuit,
When an order is assigned to each of the second power supply circuits in order of decreasing length along the power supply wiring from the first power supply circuit to the connection position of each of the second power supply circuits, At least one between the position on the power supply wiring and the ground wiring on the substrate, the length from the first power supply circuit being longer than the length to the connection position of the second second power supply circuit A power supply device provided with a capacitor. The capacitor is
In each of the second power supply circuits, the length along the wiring from the second power supply circuit to the first power supply circuit via the power supply wiring and the wiring to the capacitor via the power supply wiring 2. The power supply device according to claim 1, wherein the power supply device is provided between a position on the power supply wiring in which the shorter one is not longer than a predetermined length and the ground wiring. The capacitor is
When the number of the second power supply circuits is n (n is an integer of 3 or more), the connection position of the kth second power supply circuit and the (k + 1) th of the second power supply circuit on the power supply wiring. At least one between the position on the power supply wiring between the connection position of the two power supply circuits and the ground wiring;
If n is an even number, the value of k is n / 2,
The power supply apparatus according to claim 1, wherein when n is an odd number, a value of k is (n + 1) / 2. Six second power supply circuits are provided on the substrate,
The capacitor is
On the power supply wiring, between the position on the power supply wiring between the connection position of the third second power supply circuit and the connection position of the fourth second power supply circuit, and the ground wiring 4. The power supply device according to claim 1, wherein at least one power supply device is provided. Each of the second power supply circuits is
An inductor;
A diode;
By turning on, energy from the first power supply circuit is supplied to the inductor, and by turning off, supply of energy from the first power supply circuit to the inductor is cut off and energy stored in the inductor is stored. A switching element that emits through the diode;
Having at least
The power supply device
5. The power supply device according to claim 1, further comprising a control circuit that supplies a control signal for turning on and off the switching element to the switching element included in each of the second power supply circuits. 6. A power supply device according to any one of claims 1 to 5;
A light source as the load;
A lighting device comprising:

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