JP2014187872A - Dc power supply unit and illumination apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a DC power supply unit which can connect a plurality of luminous loads so that electric power is variable and achieve cost reduction, and an illumination apparatus which permits lighting of an illumination load to be controlled by the DC power supply unit.SOLUTION: The DC power supply 1 includes: an AC-DC converter circuit 2 with input terminals 5a, 5b connected with an AC power supply Vs and a capacitor C3 provided on the output side; a plurality of step-down chopper circuits 3a, 3b which have a pair of output terminals 6a, 6b, 7a, 7b connected with a load and a switching element Q2 connected between a low potential side of the capacitor C3 in the AC-DC converter circuit 2 and the output terminals 6b, 7b and which are connected in parallel to the capacitor C3 in the AC-DC converter circuit 2; and a control circuit 4 which on-off controls the switching element of at least one step-down chopper circuit.

Description

  The present invention relates to a DC power supply device that converts an AC voltage into a DC voltage and outputs the same, and a lighting device in which a light emitting load is controlled to be turned on by the DC power supply device.

  Light emitting diodes (LEDs) are used as light sources in general lighting equipment. This luminaire is equipped with a large number of light emitting diodes in order to obtain a predetermined illuminance (brightness). The light-emitting diodes are usually connected in series or series-parallel, and are controlled to be turned on by a DC power supply device mounted on the lighting fixture. The DC power supply device outputs a predetermined DC voltage across the light emitting diodes connected in series in order to cause a predetermined current to flow through the light emitting diode.

  In recent years, the light emitting diodes are improving in light emission efficiency, and the forward voltage Vf tends to decrease. Moreover, a small lighting fixture has a small number of light emitting diodes to be mounted. As a result, the total voltage of the forward voltage Vf of the light emitting diodes connected in series is decreasing, and the number of DC power supply devices that output a DC voltage lower than the input voltage is increasing. That is, the number of DC power supply devices using a step-down chopper circuit is increasing.

JP 2009-134945 A (page 5, FIG. 2)

  It is an object of the present invention to provide a DC power supply device capable of connecting a plurality of loads so that the power can be varied, and a lighting device in which a lighting load is controlled to be turned on by the DC power supply device.

  The invention of the DC power supply device according to claim 1 has an input terminal connected to the AC power supply and a capacitor provided on the output side, and converts the input AC voltage into a predetermined DC voltage to convert the capacitor An AC-DC conversion circuit that outputs between both ends; a pair of output terminals to which a load is connected; a switching element that is connected between the low potential side of the capacitor of the AC-DC conversion circuit and the output terminal; The output voltage of the AC-DC conversion circuit is chopped by the on / off operation of the switching element to output a DC voltage between the pair of output terminals, and connected in parallel to the capacitor of the AC-DC conversion circuit A plurality of step-down chopper circuits, and a control circuit for controlling on / off of the switching elements of at least one step-down chopper circuit. And said that you are.

  In the present invention and the following inventions, each configuration is as follows unless otherwise specified.

  The AC-DC conversion circuit converts an AC voltage into a predetermined DC voltage, such as a rectified or rectified AC voltage, or a boost chopper circuit, a step-up / down chopper circuit, or a step-down chopper circuit connected thereto. That's fine.

  A plurality of control circuits may control the switching elements of each step-down chopper circuit, or a single control circuit may be configured to control the switching elements of each step-down chopper circuit.

  According to the present invention, since a plurality of step-down chopper circuits are connected in parallel between the outputs of the AC-DC conversion circuit, the same or different loads can be connected between the outputs of the step-down chopper circuits. Can be controlled individually. In addition, since the switching element of each step-down chopper circuit is connected to the low potential side between the outputs of the AC-DC conversion circuit, it can be turned on / off by the low driving voltage output from the control circuit.

  The invention of the lighting device according to claim 2 comprises: the DC power supply device according to claim 1; and a light-emitting load connected between a pair of output terminals of the DC power supply device and controlled to be lit. It is characterized by.

  The DC power supply device may be disposed in the instrument body or may be provided separately from the instrument body.

  According to the first aspect of the present invention, the same or different loads are connected between the outputs of the respective step-down chopper circuits, and the power of the load can be individually controlled by the control circuit. In addition, the on / off drive of the switching element of each step-down chopper circuit can be performed at a low voltage output from the control circuit, so that a large-sized drive circuit or the like is not required and the DC power supply device can be downsized. Can be formed inexpensively.

  According to the second aspect of the present invention, the emitted light emitted from the light emitting load is radiated light from the light emitting loads connected between the outputs of the step-down chopper circuits of the DC power supply device. It is possible to provide an illuminating device capable of effect lighting by connecting light emitting loads having different emission colors and individually dimming the light emitting loads.

1 is a schematic circuit diagram of a DC power supply device showing Embodiment 1 of the present invention. Similarly, the schematic plan view of a light-emitting body. The schematic perspective view of the LED lighting fixture which shows Example 2 of this invention.

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

  In the present invention, a plurality of step-down chopper circuits are connected in parallel between the outputs of the AC-DC conversion circuit, and the switching element of the step-down chopper circuit is connected to the low potential side between the outputs of the AC-DC conversion circuit. ing. A load is connected between the outputs of the step-down chopper circuits. The power of the load is individually varied by controlling the switching elements of the step-down chopper circuits as desired by the control circuit.

  1 and 2 show a first embodiment of the present invention, FIG. 1 is a schematic circuit diagram of a DC power supply device, and FIG. 2 is a schematic plan view of a light emitter.

  In FIG. 1, a DC power supply device 1 includes an AC-DC conversion circuit 2, a plurality of step-down chopper circuits 3 a and 3 b, and a control circuit 4. The input terminals 5a and 5b are connected to a commercial AC power source Vs, and the output terminals 6a, 6b, 7a and 7b are connected to a light emitting diode (LED) 8 as a light emitting load to light the light emitting diode 8. Is formed. A plurality of the light emitting diodes 8 are connected in series.

  The AC-DC conversion circuit 2 includes a DC power supply circuit 9 and a boost chopper circuit 10. The DC power supply circuit 9 is formed with a full-wave rectifier circuit 11, a noise filter circuit 12 formed with a transformer T1, and a capacitor C1 acting as a noise filter. The input terminal of the full-wave rectifier circuit 11 is connected to the input terminals 5 a and 5 b via the noise filter circuit 12. A capacitor C <b> 1 is connected between the output terminals of the full-wave rectifier circuit 11. The low potential side of the capacitor C1 is connected to the ground E via the capacitor C2. The DC power supply circuit 9 full-wave rectifies an AC voltage of the commercial AC power supply Vs, for example, AC 100V, and outputs the full-wave rectified voltage across the capacitor C1.

  The step-up chopper circuit 10 chops the output voltage of the DC power supply circuit 9 and outputs a predetermined DC voltage, for example, DC 400 V, by an on / off operation of the field effect transistor Q1, which is a switching element, and has a well-known configuration. Yes. That is, a series circuit of an inductor L1 and a field effect transistor Q1 connected between both ends of the capacitor C1 of the DC power supply circuit 9, a backflow prevention diode D1 connected between the drain and source of the field effect transistor Q1, and a smoothing circuit It is formed with a series circuit of a capacitor C3. The field effect transistor Q1 is ON / OFF controlled by the control circuit 4 at a predetermined frequency and on-duty, thereby generating a predetermined DC voltage across the smoothing capacitor C3.

  Thus, the AC-DC conversion circuit 2 is configured to convert the AC voltage of the commercial AC power supply Vs, for example, AC100V, into a predetermined DC voltage, for example, DC400V, and output it.

  The step-down chopper circuits 3 a and 3 b are formed with a known configuration and are connected in parallel between outputs of the AC-DC conversion circuit 2. In the figure, two step-down chopper circuits 3a and 3b are connected. However, the number may be three or more, for example, six are connected. Further, the same reference numerals are assigned to the same parts of the step-down chopper circuits 3a and 3b.

  The step-down chopper circuits 3a and 3b are connected in parallel to a diode D2 connected in parallel to the smoothing capacitor C3 of the AC-DC conversion circuit 2 and a field effect transistor Q2 serving as a switching element, and to the diode D2. The inductor L2 and the series circuit of the smoothing capacitor C4 are connected, and the field effect transistor Q2 is connected to the voltage line A1 on the low potential side between the outputs of the AC-DC conversion circuit 2. Between both ends of the smoothing capacitor C4 is an output between the step-down chopper circuits 3a and 3b, which are connected to the output terminals 6a and 6b and the output terminals 7a and 7b, respectively, and connected in series as light-emitting diodes (LEDs). ) 8 is connected.

  The field effect transistor Q2 has its gate and source connected to the control circuit 4, and is turned on when a control signal (driving voltage) of, for example, DC 3 to 4 V output from the control circuit 4 is applied. That is, the field effect transistor Q <b> 2 is turned on / off by the control signal output from the control circuit 4. As a result, the predetermined DC voltage output from the AC-DC conversion circuit 2 is chopped, and a DC voltage corresponding to the on / off operation of the field effect transistor Q2 is generated across the smoothing capacitor C4.

  The light emitting diodes 8 are of the same type, and when a DC voltage output from the step-down chopper circuits 3a, 3b,... Is applied between both ends thereof, a current flows and lights up, and visible light (for example, used as illumination light) White light). And as shown in FIG. 2, it mounts on each circuit board 13a-13f, and comprises each LED module 14a-14e. The LED modules 14a to 14e are connected to the step-down chopper circuits 3a, 3b,. And each LED module 14a-14e gathers and the light-emitting body 15 is formed.

  In FIG. 1, the control circuit 4 is formed having an integrated circuit (IC). Then, a drive voltage (DC 3 to 4 V) having a predetermined on / off frequency and on-duty is output between the gate and source of the field effect transistor Q2, and the field effect transistor Q2 is on / off controlled. That is, a constant DC voltage is output between both ends of the smoothing capacitor C4 of each step-down chopper circuit 3a, 3b... (Between the output terminals 6a, 6b, 7a, 7b...).

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

  When the commercial AC power supply Vs is turned on, the AC-DC conversion circuit 2 changes the AC voltage of the commercial AC power supply Vs, for example, AC100V, to a predetermined DC voltage, for example, DC400V, according to the on / off control of the field effect transistor Q1 by the control circuit 4. It converts and outputs between both ends of the smoothing capacitor C3.

  The field effect transistor Q2 of each step-down chopper circuit 3a, 3b,... Is controlled to be turned on / off by the control circuit 4 at a predetermined on / off frequency or on duty, whereby a predetermined DC voltage output from the AC-DC conversion circuit 2 is changed. The chopping generates a constant DC voltage across the smoothing capacitor C4 of each step-down chopper circuit 3a, 3b. This DC voltage is applied across the light emitting diodes 8 connected in series between the output terminals 6a, 6b, 7a, 7b. The light emitting diode 8 is lit and emits visible light. That is, visible light is emitted from the light emitter 15.

  For example, when a dimming signal is transmitted from an external dimmer, the control circuit 4 changes the on / off frequency and on-duty of the field effect transistor Q2 in accordance with the dimming signal. As a result, the DC voltage generated across the smoothing capacitor C4 changes, the current flowing through the light emitting diode 8 changes, and the light output of the light emitting diode 8 changes. That is, the light emitting diode 8 is dimmed and the amount of light emitted from the light emitter 15 changes. In this way, by transmitting a dimming signal from the external dimmer and controlling the on / off of the field effect transistor Q2 by the control circuit 4, the current flowing through the light emitting diode 8 can be reduced. Can be dimmed.

  When a disconnection or the like occurs in any of the light emitting diodes 8 connected in series to the output terminals 6a, 6b, 7a, 7b... Of each step-down chopper circuit 3a, 3b. Turns off. That is, no visible light is emitted from one of the LED modules 14 a to 14 f of the light emitter 15. Even in this case, since the visible light is radiated from the remaining LED modules 14a to 14f of the light emitter 15, illumination light can be obtained although it is not perfect.

  Moreover, each LED module 14a-14f may each be mounted in a lighting fixture. Thereby, lighting control of a some lighting fixture can be carried out by the one DC power supply device 1. FIG. Moreover, you may connect the light emitting diode 8 from which luminescent color differs to each output terminal 6a, 6b, 7a, 7b .... The control circuit 4 individually controls the step-down chopper circuits 3a, 3b,... According to the dimming signal, so that radiated light of different emission colors can be emitted from the light emitter 15 and mixed. An illumination effect can be achieved by adjusting the mixing ratio by lighting or the like. Thus, the DC power supply device 1 with improved versatility can be provided.

  The field effect transistor Q2 of each step-down chopper circuit 3a, 3b,... Is connected to the low potential side between the outputs of the AC-DC conversion circuit 2, and is turned on / off by the low drive voltage output from the control circuit 4. Since it operates, a large drive circuit or the like is not required, and thus the DC power supply 1 can be reduced in size and can be formed at low cost.

  In addition, although the direct-current power supply device 1 was formed so as to control the lighting of the light emitting diode 8 as a load, it is not limited thereto, and may be a device that controls a control device, an electric device such as a motor or a heater.

  FIG. 3 is a schematic perspective view of an LED lighting apparatus showing Embodiment 2 of the present invention. 1 and 2 are denoted by the same reference numerals and description thereof is omitted.

  The LED lighting fixture 16 shown in FIG. 3 is a general lighting fixture that is directly attached to or suspended from a ceiling surface, for example, and has a fixture main body 17 formed in a substantially rectangular box shape and a light source disposed in the fixture main body 17. A unit 18 is provided. The light emitting diode 8 is provided on the light source unit 18 side by the light emitter 15.

  The light source unit 18 includes a unit main body 19 and a cover body 20. The unit body 19 is formed in a bottomed frame having a dimension in the longitudinal direction equivalent to that of the instrument body 17 and a dimension in the width direction larger than that of the instrument body 17 and having a relatively shallow depth. Is formed.

  The light emitter 15 is attached with screws or the like (not shown) such that the light emitting diode 8 is positioned on the opening 19a side of the unit body 19.

  The cover body 20 includes a rectangular translucent plate 21 as a translucent member made of, for example, acrylic resin. And it attaches to the instrument main body 17 via the unit main body 19 with screws 22, 22 so as to close the opening 19 a of the unit main body 19. The light emitter 15 is covered with a translucent plate 21.

  And the instrument main body 17 has arrange | positioned the DC power supply device 1 which is not illustrated in the inside. In the DC power supply device 1, the output terminals 6 a, 6 b, 7 a, 7 b... Are connected to the light emitter 15 by lead wires (not shown) and are connected to the light emitting diode 8.

  When the AC voltage of the commercial AC power supply Vs is applied to the DC power supply device 1, the light emitting diode 8 is turned on, and visible light, for example, white light is emitted from the light emitting diode 8. This radiated light passes through the light transmitting plate 21 of the unit main body 19 and illuminates the floor side located on the lower side of the instrument main body 17.

  Since the LED lighting fixture 16 as a lighting device can transmit a dimming signal from an external dimmer to dimm the light emitting diode 8, power saving can be achieved. In addition, since the light emitter 15 includes the light emitting diodes 8 having different emission colors, the light emitting diodes 8 can be dimmed and the like can be illuminated.

  INDUSTRIAL APPLICABILITY The present invention is used for a power supply device that supplies power to a control device or an electric device such as a motor or a heater in addition to a lighting device that lights a surface light source such as a light emitting diode (LED) or an organic electroluminescence (EL) element. be able to.

DESCRIPTION OF SYMBOLS 1 ... DC power supply device 2 ... AC-DC conversion circuit 3a, 3b ... Step-down chopper circuit 4 ... Control circuit 5a, 5b ... Input terminal 6a, 6b, 7a, 7b ... Output terminal 8 ... Light emitting diode 16 as illumination load ... Illumination LED lighting fixture C3 as a device ... smoothing capacitor Q2 as a capacitor ... field effect transistor as a switching element

Claims (2)

An AC-DC conversion circuit that has an input terminal connected to an AC power source and a capacitor provided on the output side, converts the input AC voltage into a predetermined DC voltage, and outputs the DC voltage between both ends of the capacitor;
A pair of output terminals to which a load is connected; and a switching element connected between the low potential side of the capacitor of the AC-DC conversion circuit and the output terminal. A plurality of step-down chopper circuits chopping the output voltage of the AC-DC conversion circuit to output a DC voltage between the pair of output terminals and connected in parallel to a capacitor of the AC-DC conversion circuit;
A control circuit for controlling on / off of the switching element of at least one step-down chopper circuit;
A direct current power supply device comprising: A DC power supply device according to claim 1;
A light emitting load connected between a pair of output terminals of the DC power supply device and controlled to be lit;
An illumination device comprising:

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