JP2011030310A - Power supply device and luminaire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharging lamp lighting device capable of more efficiently suppressing noise generated due to switching a field-effect transistor while reducing a mounting area. <P>SOLUTION: A chip capacitor C4 for suppressing noise generated due to switching of the field-effect transistor Q1 is disposed on the output side of a power factor improving circuit 12. With this configuration, the chip capacitor C4 is disposed more closely to the field-effect transistor Q1 or the like as compared to a film capacitor or the like, so that a mounting area can be reduced. A section in which a high-frequency current generated by switching the field-effect transistor Q1 can be reduced to the shortest, and thus, the noise generated by the switching of the field-effect transistor Q1 can be more efficiently suppressed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power supply device including at least one switching element, and having a conversion circuit that converts an AC input power source into a DC power source and outputs the DC power source to a load side, and a lighting fixture including the power source device.

  2. Description of the Related Art Conventionally, for example, a power supply device connected to a discharge lamp as a load has a power factor improvement circuit that has a switching element and converts an input voltage from a power supply unit into a boosted DC voltage, and is output from the power factor improvement circuit. Power conversion having an inverter circuit for lighting a discharge lamp by converting a DC voltage into a high frequency voltage, and an LC resonance circuit for controlling power supplied from the inverter circuit that is electrically connected between the inverter circuit and the discharge lamp A circuit or the like (see, for example, Patent Document 1).

JP2009-152168A (page 7-10, FIG. 7)

  In the above-described configuration, for example, a film capacitor is used in order to suppress high-frequency noise associated with switching of the switching element of the power factor correction circuit, and this film capacitor is disposed close to the switching element.

  However, since the shape of the film capacitor is large, there is a limitation in arrangement, and not only the film capacitor cannot be arranged close to the switching element that becomes a noise source, but also an inductance component is generated by the lead wire, and noise is reduced. There is a problem that it may not be sufficient.

  The present invention has been made in view of such a point, and an object thereof is to provide a power supply device that can more effectively suppress noise generated by switching of a switching element while suppressing a mounting area, and a lighting fixture including the same. And

  A power supply device according to claim 1, comprising at least one switching element, a conversion circuit for converting an AC input power source to a DC power source and outputting it to a load side; and a switching circuit disposed on the output side of the conversion circuit, And a chip capacitor that suppresses noise generated by switching.

  The conversion circuit is, for example, a power factor correction circuit such as a boost chopper circuit.

  For example, a field effect transistor is preferably used as the switching element.

  For example, a discharge lamp is preferably used as the load.

  As the chip capacitor, for example, a ceramic chip capacitor having C0G characteristics or U2J characteristics is used.

  A power supply device according to a second aspect is the power supply device according to the first aspect, wherein the chip capacitor is disposed close to the switching element of the conversion circuit.

  A power supply device according to claim 3 is the power supply device according to claim 1, further comprising: a power conversion circuit that includes at least one switching element, converts a DC power output from the conversion circuit, and supplies the DC power to a load. The capacitor is disposed close to the switching element of the power conversion circuit.

  The power conversion circuit includes, for example, an inverter circuit and a resonance circuit.

  A power supply device according to a fourth aspect is the power supply device according to the first aspect, wherein the conversion circuit includes a smoothing capacitor on the output side, and the chip capacitor is disposed close to the smoothing capacitor.

  As the smoothing capacitor, for example, an electrolytic capacitor is used.

  According to a fifth aspect of the present invention, there is provided a lighting fixture comprising: the power supply device according to any one of the first to fourth aspects; and a fixture main body to which a discharge lamp as a load is attached.

  According to the power supply device of the first aspect, the chip capacitor can be disposed close to the switching element or the like by disposing the chip capacitor for suppressing noise generated by switching of the switching element on the output side of the conversion circuit. The area can be suppressed, and a portion where a high-frequency current generated by switching of the switching element flows can be shortened, and noise generated by switching of the switching element can be more effectively suppressed.

  According to the power supply device according to claim 2, in addition to the effect of the power supply device according to claim 1, the chip capacitor is arranged in the vicinity of the switching element of the conversion circuit, so that Noise generated by switching of the switching elements of the conversion circuit can be more effectively suppressed while effectively using space to suppress the mounting area.

  According to the power supply device according to claim 3, in addition to the effect of the power supply device according to claim 1, the chip capacitor is disposed in the vicinity of the switching element of the power conversion circuit, thereby The noise generated by switching of the switching element of the conversion circuit can be suppressed more effectively while suppressing the mounting area while effectively using the surrounding space.

  According to the power supply device according to claim 4, in addition to the effect of the power supply device according to claim 1, the chip capacitor is arranged in the vicinity of the smoothing capacitor on the output side of the conversion circuit, so that It is possible to more effectively suppress noise generated by switching of the switching elements of the conversion circuit while suppressing the mounting area while effectively using the space.

  According to the lighting fixture of Claim 5, each effect can be show | played by providing the power supply device as described in any one of Claim 1 thru | or 4.

1 is a circuit diagram of a power supply device showing a first embodiment of the present invention. It is a perspective view which shows typically the one main surface side of the board | substrate of a power supply device same as the above. It is a top view which shows typically the back surface side of a board | substrate same as the above. It is a perspective view of the lighting fixture provided with the power supply device same as the above. It is a circuit diagram of the power supply device which shows the 2nd Embodiment of this invention. It is a circuit diagram of the power supply device which shows the 3rd Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  1 to 4 show a first embodiment, FIG. 1 is a circuit diagram of a power supply device, FIG. 2 is a perspective view schematically showing one main surface side of a substrate of the power supply device, and FIG. 3 is a back surface of the substrate. FIG. 4 is a perspective view of a luminaire provided with a power supply device.

  As shown in FIG. 1, a discharge lamp lighting device 10 which is a hot cathode discharge lamp lighting device as a power supply device, that is, an electronic ballast, has a DC output (DC voltage) from the power supply portion 11 on the output side of the power supply portion 11. ) Is converted to a power factor correction (PFC) circuit 12 as a conversion circuit for boosting the voltage, and a DC output (DC voltage) from the power factor improvement circuit 12 is connected to the output side of the power factor improvement circuit 12 at a high frequency. An inverter circuit 13 that converts and outputs an alternating voltage is electrically connected, and a resonant circuit 14 that outputs a voltage corresponding to the output frequency of the inverter circuit 13 is electrically connected to the output side of the inverter circuit 13. A discharge lamp FL such as a hot cathode fluorescent lamp as a load is detachably mounted on the output side of the resonance circuit 14. The discharge lamp lighting device 10 includes a control element 16 that controls the power factor correction circuit 12, the inverter circuit 13, and the resonance circuit 14. The control element 16 is a driver unit for driving the inverter circuit 13. The drive element 17 is electrically connected. The discharge lamp lighting device 10 is mounted on a long board B shown in FIGS.

  The power supply unit 11 shown in FIG. 1 has an overcurrent protection fuse FU and a noise filter circuit 18 connected to an AC power supply e such as 100 V to 242 V, and a bridge on the output side of the noise filter circuit 18. A full-wave rectifying element REC for rectification such as a diode is connected.

  The noise filter circuit 18 is a line filter composed of a capacitor C1, a common mode choke L1, and a capacitor C2. The noise filter circuit 18 prevents high-frequency noise generated from the power factor correction circuit 12 and the inverter circuit 13 from being output to the power source e side.

  Capacitors C1 and C2 and common mode choke L1 are each mounted near one end in the longitudinal direction of substrate B on surface Ba, which is one main surface of substrate B, as shown in FIG.

  The full-wave rectifying element REC shown in FIG. 1 is a bridge circuit including four diodes D1 to D4 that are rectifying elements, for example. As shown in FIG. It is surface-mounted on the surface, that is, the back surface Bb.

  The power factor correction circuit 12 shown in FIG. 1 is, for example, a boost chopper circuit. This power factor improvement circuit 12 is a boosting transformer between the inverter circuit 13 and the output side of the full-wave rectifying element REC. A series circuit of a chopper choke L2 and reverse blocking diode D5 is electrically connected, and a capacitor C3 is electrically connected in parallel to the connection point between the chopper choke L2 and the full-wave rectifier element REC. A first switching element as a switching element, that is, a field effect transistor (FET) Q1, which is a chopping switching element, is electrically connected in parallel to a connection point between the chopper choke L2 and the anode of the diode D5. Further, a parallel circuit of a noise suppressing chip capacitor C4 and an electrolytic capacitor C5 which is a smoothing capacitor is electrically connected to the cathode side of the diode D5 which is the output side of the power factor correction circuit 12.

  In the chopper choke L2, the primary winding is electrically connected between the output side of the full-wave rectifying element REC and the anode of the diode D5, and one end side of the secondary winding is electrically connected to the ground potential. The other end side is electrically connected to the control element 16. Therefore, a choke voltage is input to the control element 16. The chopper choke L2 is mounted at a position closer to one end of the surface Ba of the substrate B as shown in FIG.

  In the field effect transistor Q1 shown in FIG. 1, the drain terminal is electrically connected to the connection point between the chopper choke L2 and the anode of the diode D5, and the source terminal on the output side is electrically connected to the ground potential. In addition, a gate terminal which is a control terminal is electrically connected to the control element 16. Further, as shown in FIG. 2, the field effect transistor Q1 is thermally connected to the heat radiating plate HS at a position closer to one end than the center in the longitudinal direction of the substrate B on the surface Ba of the substrate B. It is implemented in the state.

  The chip capacitor C4 shown in FIG. 1 is a ceramic chip capacitor, for example, and is mounted at a position close to the field effect transistor Q1. When mounting the chip capacitor C4, as close as possible to the cathode terminal of the diode D5 and the drain terminal on the output side of the field effect transistor Q1, that is, the wiring leading out from these terminals to the chip capacitor C4 was shortened. It is preferable to connect in a state.

  As the chip capacitor C4, for example, a capacitor having C0G characteristics or U2J characteristics defined in the EIA standard is preferably used. Here, the C0G characteristic refers to a characteristic in which the compensation range of the change rate of capacitance in the temperature range of −55 ° C. to 125 ° C. is 0 ± 30 ppm / ° C., and the U2J characteristic refers to the temperature range of −25 ° C. to 85 ° C. A characteristic in which the compensation range of the rate of change in capacitance at ° C. is −750 ± 120 ppm / ° C.

  Further, the inverter circuit 13 is a so-called half-bridge type in which field effect transistors Q2 and Q3 which are second switching elements as switching elements, that is, inverter switching elements, are electrically connected in series.

  In the field effect transistors Q2 and Q3, the gate terminal as a control terminal is electrically connected to the drive element 17, and on / off is controlled by a signal supplied from the drive element 17.

  The resonance circuit 14 includes a series circuit of a DC cut capacitor C6 electrically connected to both ends of the field effect transistor Q3 and a primary winding of a resonance inductance L3 which is a ballast choke as an inductor. A resonant capacitor C7, which is a capacitor in parallel with the discharge lamp FL, is electrically connected to the output side of the primary winding of the resonant inductance L3. The resonance circuit 14 and the inverter circuit 13 constitute a power conversion circuit 21.

  As shown in FIG. 2, the resonant inductance L3 is mounted on the surface Ba of the substrate B at a position near the other end in the longitudinal direction of the substrate B.

  In the discharge lamp FL shown in FIG. 1, a preheating circuit (not shown) is electrically connected to the filaments FLa and FLb. This preheating circuit is electrically connected to the secondary winding of the resonant inductance L3, for example.

  The control element 16 is, for example, a so-called IC (integrated circuit) of a surface mount type, a power factor improvement control unit 23 electrically connected to the power factor improvement circuit 12, and a discharge lamp that is a load voltage (load current) Based on the state detection unit 24 that detects the operation state of the power conversion circuit 21 such as the inverter circuit 13 and the resonance circuit 14 by detecting the voltage (discharge lamp current), and the operation state detected by the state detection unit 24 An oscillation control unit 25 that generates a frequency signal P for controlling the operation of the field effect transistors Q2 and Q3 of the inverter circuit 13 and outputs the frequency signal P to the drive element 17 is integrally provided.

  Note that the fact that the control element 16 is integrally provided with the parts 23, 24, 25 and the like means that these are integrated in the control element 16.

  The power factor correction control unit 23 is a chopping that is a switching pulse of the field effect transistor Q1, based on a predetermined signal such as an input voltage, a DC output voltage, a choke voltage, and a switching current flowing in the field effect transistor Q1 on the power supply unit 11 side. It has a function to generate and output a commercial frequency signal PC.

  The state detection unit 24 is configured to control the drive element 17 via the oscillation control unit 25 in accordance with the state of the discharge lamp FL (the state of the power conversion circuit 21) based on the detected discharge lamp current (discharge lamp voltage). Has been.

  The oscillation controller 25 has a function of generating a frequency signal P having a predetermined frequency based on the lighting state of the discharge lamp FL detected by the state detector 24.

  The state detection unit 24, the oscillation control unit 25, and the like constitute a conversion control unit 27 that controls the operation of the power conversion circuit 21. That is, the conversion control unit 27 can control the entire power conversion circuit 21 such as control of the inverter circuit 13, start sequence of the discharge lamp FL, and circuit protection.

  Further, the drive element 17 sets the field effect transistors Q2 and Q3 at a frequency of about several tens of kHz to 200 kHz, for example, 50 kHz or more, according to the frequency signal P for dimming supplied from the oscillation control unit 25 of the control element 16. By alternately turning on / off (switching driving), a predetermined high-frequency alternating current is generated between the drain and source of the field effect transistor Q3.

  And as shown in FIG. 4, the discharge lamp lighting device 10 comprised in this way is applicable to the lighting fixture as an electric equipment. This lighting fixture includes a fixture main body 31 in which the discharge lamp lighting device 10 is arranged, sockets 32 to which straight tube-type discharge lamps FL are attached at both ends of the fixture main body 31, and the like.

  Next, the operation of the first embodiment will be described.

  When the discharge lamp lighting device 10 shown in FIG. 1 is activated, power is supplied from the high voltage side of the electrolytic capacitor C5 of the power factor correction circuit 12 to the control element 16, and the control element 16 is activated.

  Then, the control element 16 generates the chopping frequency signal PC by the power factor improvement control unit 23 and performs the switching operation of the field effect transistor Q1, thereby changing the phase of the input voltage rectified by the power source unit 11 to the power factor improvement circuit. 12 improves the power factor to match the phase of the input current.

  Specifically, when the field effect transistor Q1 is turned on, a linearly increasing current flows through the chopper choke L2 (diode D5), so that a choke current flows through the secondary winding of the chopper choke L2, and the chopper choke Electromagnetic energy is stored in L2. When the detected switching current reaches a predetermined value, the power factor correction control unit 23 outputs an off chopping frequency signal PC to the gate terminal of the field effect transistor Q1 to turn off the field effect transistor Q1. As a result, the electromagnetic energy accumulated in the chopper choke L2 is released, and a linearly decreasing current flows through the chopper choke L2 (diode D5). The output current from the power factor correction circuit 12 flows to the chip capacitor C4, and this chip capacitor C4 acts as a bypass capacitor, and the switching noise of the field effect transistor Q1 superimposed on the output current is bypassed to the ground potential.

  The output voltage output from the power factor correction circuit 12 is smoothed by the electrolytic capacitor C5 to become a DC voltage, and is input to the inverter circuit 13 of the power conversion circuit 21. In this inverter circuit 13, the drive element 17 is driven by the frequency signal P generated by the oscillation control unit 25 of the control element 16, so that the field effect transistors Q2 and Q3 are turned on and off at a predetermined frequency such as 50 kHz. Therefore, the input DC voltage is converted into a high frequency AC voltage.

  Due to this high frequency AC voltage, the resonance circuit 14 resonates and a resonance current flows, and the filaments FLa and FLb of the discharge lamp FL are preheated by the preheating circuit.

  Then, a predetermined starting voltage is applied between the filaments FLa and FLb by preheating the filaments FLa and FLb, the discharge lamp FL is turned on (started), and this discharge lamp FL is steadily lit.

  At this time, the power conversion circuit 21 generates a frequency signal P supplied from the oscillation control unit 25 to the drive element 17 based on the discharge lamp current (discharge lamp voltage) detected by the state detection unit 24. Then, the drive frequency of the inverter circuit 13 is varied, and feedback control is performed so that the discharge lamp current (discharge lamp voltage, discharge lamp power) becomes a predetermined target value.

  As described above, according to the first embodiment, the chip capacitor C4 for suppressing noise generated by the switching of the field effect transistor Q1 is arranged on the output side of the power factor correction circuit 12, for example, a film capacitor. The chip capacitor C4 can be placed closer to the field effect transistor Q1 etc. compared to the case of using the The noise generated by switching the field effect transistor Q1 can be more effectively suppressed.

  In particular, since the chip capacitor C4 does not have a lead like a film capacitor or the like, the inductance component generated by this lead can be extremely reduced, so that the high frequency noise generated by the switching of the field effect transistor Q1 can be reduced. On the other hand, an increase in impedance due to the inductance component can be suppressed, and noise generated by switching of the field effect transistor Q1 can be more effectively suppressed.

  In addition, by arranging the chip capacitor C4 close to the field effect transistor Q1, the space around the field effect transistor Q1 is effectively used to reduce the mounting area, and is generated by switching the field effect transistor Q1. Noise can be suppressed more effectively.

  Further, by using a chip capacitor C4 having a C0G characteristic or U2J characteristic, for example, a chip capacitor having an X7R characteristic (with a compensation range of ± 15% for the rate of change in capacitance at a temperature range of −55 ° C. to 125 ° C. Compared with the case of using a characteristic), the temperature dependency is not only small, the dielectric loss tangent (tan δ) is small, the high frequency impedance component can be suppressed, and noise can be reduced.

  Next, FIG. 5 shows a second embodiment, and FIG. 5 is a circuit diagram showing a power supply device. In addition, about the structure and effect | action similar to the said 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the second embodiment, the chip capacitor C4 of the first embodiment is mounted at a position close to the field effect transistors Q2 and Q3 of the power conversion circuit 21.

  That is, the chip capacitor C4 is electrically connected in parallel to the series circuit of the field effect transistors Q2 and Q3. When mounting the chip capacitor C4, the source terminal on the input side of the field effect transistor Q2 and the drain terminal on the output side of the field effect transistor Q3 are as close as possible, that is, from these terminals to the chip capacitor C4. It is preferable to connect in a state where the wiring to be drawn out is shortened.

  Then, the chip capacitor C4 that suppresses noise generated by the switching of the field effect transistor Q1 is arranged on the output side of the power factor correction circuit 12, and thus has the same configuration as that of the first embodiment, so that the first The same effects as those of the first embodiment can be achieved.

  Further, by disposing the chip capacitor C4 close to the field effect transistors Q2 and Q3, the space around the field effect transistors Q2 and Q3 is effectively used to reduce the mounting area, and the power factor improvement circuit 12 Noise generated by switching of the field effect transistor Q1 can be more effectively suppressed.

  Next, FIG. 6 shows a third embodiment, and FIG. 6 is a circuit diagram showing a power supply device. In addition, about the structure and effect | action similar to said each embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the third embodiment, the chip capacitor C4 of the first embodiment is mounted close to the electrolytic capacitor C5.

  That is, the chip capacitor C4 is electrically connected between both leads of the electrolytic capacitor C5. When mounting the chip capacitor C4, it is preferable to connect as close as possible to both terminals of the electrolytic capacitor C5, that is, in a state in which the wiring drawn from these terminals to the chip capacitor C4 is short.

  Then, the chip capacitor C4 that suppresses noise generated by the switching of the field effect transistor Q1 is arranged on the output side of the power factor correction circuit 12, and thus has the same configuration as that of the first embodiment, so that the first The same effects as those of the first embodiment can be obtained.

  In addition, by placing the chip capacitor C4 close to the electrolytic capacitor C5, the space around the electrolytic capacitor C5 is effectively used to reduce the mounting area, and the field effect transistor Q1 of the power factor correction circuit 12 is switched. The noise generated by can be more effectively suppressed.

  In each of the above embodiments, the detailed configuration of the power supply unit 11, the inverter circuit 13, the resonance circuit 14, and the like is not limited to the above configuration and control.

  Further, as the load, not only a discharge lamp but also various other loads can be used.

10 Discharge lamp lighting device as a power supply
12 Power factor correction circuit as a conversion circuit
21 Power conversion circuit
31 Instrument body
C4 chip capacitor
C5 Electrolytic capacitor as a smoothing capacitor
Discharge lamp as FL load
Q1, Q2, Q3 Field effect transistors as switching elements

Claims (5)

A conversion circuit comprising at least one switching element and converting an AC input power source to a DC power source and outputting the DC power source to the load side;
A chip capacitor disposed on the output side of the conversion circuit and suppressing noise generated by switching of the switching element;
A power supply device comprising: The power supply device according to claim 1, wherein the chip capacitor is disposed in proximity to the switching element of the conversion circuit. A power conversion circuit including at least one switching element, converting a DC power output from the conversion circuit and supplying the converted power to a load;
The power supply device according to claim 1, wherein the chip capacitor is disposed in proximity to the switching element of the power conversion circuit. The conversion circuit has a smoothing capacitor on the output side,
The power supply device according to claim 1, wherein the chip capacitor is disposed close to the smoothing capacitor. A power supply device according to any one of claims 1 to 4;
An appliance body to which a discharge lamp as a load is attached;
The lighting fixture characterized by comprising.

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