JP2009189184A - Power supply device and lighting fixture - Google Patents

Abstract

A power supply device and a lighting fixture capable of reliably turning off a semiconductor light emitting element in an energized state are provided.
A power supply device for converting energy released through a secondary winding 16b of a switching transformer 16 into a DC output by a rectifying and smoothing circuit 23 by turning on and off a switching transistor 17 and lighting light emitting diodes 24 to 27 by the DC output. When the light emitting diodes 24 to 27 are turned on, the current flowing through the light emitting diodes 24 to 27 is controlled to be constant according to the detection signal of the current detection unit 29, and when the light emitting diodes 24 to 27 are turned off, the reference value is used. The voltage applied to the light emitting diodes 24 to 27 is controlled to a constant voltage lower than the lighting start voltage based on the comparison result between the voltage value lower than the preset lighting start voltage of the light emitting diodes 24 to 27 and the detection signal of the voltage detector 28. To do.
[Selection] Figure 3

Description

  The present invention relates to a power supply device and a lighting fixture that are optimal for driving a semiconductor light emitting element such as a light emitting diode.

  Recently, as a power source for a semiconductor light emitting element such as a light emitting diode, a DC power source device using a switching means is often used.

As this type of power supply device, as disclosed in Patent Document 1, a voltage detection circuit for detecting an output voltage of a DC-DC converter and an output current supplied from the DC-DC converter to a light source such as a light emitting diode are detected. It is known to have a current detection circuit and adjust the output of the DC-DC converter based on the voltage detection circuit, the detection voltage of the current detection circuit, and the detection current.
JP 2006-210835 A

  By the way, such a power supply device is applied to, for example, a lighting fixture that turns on and off a light source by detecting the presence or absence of a person or the like, or a lighting fixture that turns on and off a lighting light source used for stage production. There is. A power supply device used for such a lighting fixture needs to promptly start up the operation when the light source is turned on and off. Therefore, the light-emitting diode as the light source can be turned on and off while being energized. desired.

  However, for example, when the current flowing through the light emitting diode is detected by a current detection circuit and the light emitting diode is turned on with a substantially constant current based on the detection signal of the current detection circuit, the light emitting diode is turned off to turn off the light emitting diode. Even if the current flowing through the diode is controlled to be as small as possible, for example, about 100 μA, the light emitting diode continues to be lit and it becomes difficult to turn off the light. On the other hand, when the voltage applied to the light emitting diode is detected by the voltage detection circuit and the light emitting diode is turned on with a substantially constant voltage based on the detection signal of the voltage detection circuit, the light emitting diode is caused by variations in characteristics of the light emitting diode. Since the currents flowing through are different from each other, the desired bright and dark ones are generated, resulting in a problem that the merchantability as a lighting fixture is impaired.

  This invention is made | formed in view of the said situation, and it aims at providing the power supply device and lighting fixture which can light-off a semiconductor light-emitting element reliably in an electricity supply state.

  The invention according to claim 1 is driven by the switching means and generates a direct current output from the alternating current power of the alternating current power supply through the rectifying and smoothing means; and lighting by the direct current output generated by the direct current output generation means And a voltage control means for controlling a voltage applied to the semiconductor light emitting element by turning off the semiconductor light emitting element to be equal to or lower than a lighting start voltage of the semiconductor light emitting element. .

  According to a second aspect of the present invention, in the first aspect of the invention, the voltage control means is configured such that the semiconductor light emitting element is based on a comparison result between a preset voltage reference value and a voltage applied to the semiconductor light emitting element. The voltage applied to is controlled to a constant voltage equal to or lower than the lighting start voltage of the semiconductor light emitting element.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, based on a comparison result between a preset current reference value and a current supplied to the semiconductor light emitting element by a lighting operation of the semiconductor light emitting element. And a current control means for controlling the current supplied to the semiconductor light emitting element to be constant.

  According to a fourth aspect of the present invention, there is provided a lighting fixture comprising the power supply device according to any one of the first to third aspects and a fixture main body having the power supply device.

  According to the first aspect of the present invention, it is possible to provide a power supply device capable of reliably turning off the semiconductor light emitting element in an energized state.

  According to the second aspect of the present invention, the voltage applied to the semiconductor light emitting element can be controlled to a constant voltage equal to or lower than the lighting start voltage of the semiconductor light emitting element, and the semiconductor light emitting element can be turned off while being energized.

  According to the third aspect of the invention, even if the characteristics of the semiconductor light emitting device are further varied, substantially the same brightness can be obtained in the semiconductor light emitting device.

  According to invention of Claim 4, the lighting fixture which can light-extinguish a semiconductor light emitting element reliably in an electricity supply state can be provided.

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

(First embodiment)
First, the lighting fixture to which the power supply device of the present invention is applied will be briefly described. 1 and 2, reference numeral 1 denotes an instrument body, and the instrument body 1 is made of aluminum die-casting and has a cylindrical shape with both ends opened. The appliance body 1 is internally divided into three in the vertical direction by partition members 1 a and 1 b, and a space between the lower opening and the partition member 1 a is formed in the light source unit 2. The light source unit 2 is provided with a plurality of LEDs 2a and reflectors 2b as semiconductor light emitting elements. The plurality of LEDs 2a are arranged and mounted at equal intervals along the circumferential direction of a disk-shaped wiring board 2c provided on the lower surface of the partition member 1a.

  A space between the partition members 1 a and 1 b of the instrument body 1 is formed in the power supply chamber 3. In the power supply chamber 3, a wiring board 3a is disposed on the partition member 1a. The wiring board 3a is provided with each electronic component constituting the power supply device of the present invention for driving the plurality of LEDs 2a. The DC power supply device and the plurality of LEDs 2 a are connected by lead wires 4.

  A space between the partition plate 1 b of the instrument body 1 and the upper opening is formed in the power supply terminal chamber 5. In the power terminal room 5, a power terminal block 6 is provided on the partition plate 1b. This power supply terminal block 6 is a terminal block for supplying AC power of commercial power to the power supply device in the power supply chamber 3, and serves as a power cable terminal portion on both sides of the box 6a made of electrically insulating synthetic resin. It has an insertion port 6b, an insertion port 6c serving as a feed cable terminal, a release button 6d for separating the power line and the feed line, and the like.

  FIG. 3 shows a schematic configuration of the power supply device of the present invention incorporated in the power supply chamber 3 of the lighting fixture configured as described above.

  In FIG. 3, 11 is an AC power source, and this AC power source 11 is a commercial power source (not shown). The AC power supply 11 is connected to an input terminal of a full-wave rectifier circuit 13 via a power switch 12. The full-wave rectifier circuit 13 generates an output obtained by full-wave rectifying the AC power from the AC power supply 11.

  A ripple current smoothing capacitor 14 is connected between the positive and negative output terminals of the full-wave rectifier circuit 13. A series circuit of a primary winding 16a of a switching transformer 16 as a flyback transformer and a switching transistor 17 as a switching means is connected to both ends of the capacitor 14. The switching transformer 16 has a secondary winding 16b magnetically coupled to the primary winding 16a.

  Connected to both ends of the primary winding 16a of the switching transformer 16 is a snubber circuit 211 composed of a parallel circuit of a capacitor 18 and a resistor 19 and a series-parallel circuit of a diode 20 of the polarity shown. This snubber circuit 211 absorbs the flyback voltage generated in the primary winding 16 a of the switching transformer 16 by charging by the capacitor 18 and discharging of the resistor 19, and absorbs the ringing voltage generated by the leakage inductance of the switching transformer 16 by the capacitor 18. To do.

  The secondary winding 16b of the switching transformer 16 is connected to a rectifying / smoothing circuit 23 including a diode 21 having a polarity shown and a smoothing capacitor 22 as rectifying / smoothing means. This rectifying / smoothing circuit 23 constitutes a DC output generating means together with the switching transistor 17 and the switching transformer 16, rectifies the AC output generated from the secondary winding 16b of the switching transformer 16 by the diode 21, and this rectified output is smoothed by the smoothing capacitor. 22 is smoothed and generated as a DC output.

  At both ends of the smoothing capacitor 22 of the rectifying and smoothing circuit 23, a plurality of (four in the illustrated example) semiconductor light-emitting elements connected in series correspond to the light-emitting diodes 24-27 (LED 2a described in FIG. 2). ) Is connected.

  A voltage detection unit 28 is connected in parallel to the series circuit of the light emitting diodes 24 to 27. The voltage detection unit 28 detects a voltage applied to the light emitting diodes 24 to 27 and outputs a detection signal corresponding to the detection voltage.

  A current detection unit 29 is connected in series to the series circuit of the light emitting diodes 24 to 27. The current detection unit 29 detects the current supplied to the light emitting diodes 24 to 27 and outputs a detection signal corresponding to the detection current.

  A control circuit 30 composed of a microcomputer or the like is connected to the voltage detection unit 28 and the current detection unit 29 as control means. The control circuit 30 is connected to a turn-on / off instruction unit 31 and a dimming operation unit 32 as dimming means. The turn-on / off instruction unit 31 outputs a turn-on instruction signal or a turn-off instruction signal in response to turning on or off of the light emitting diodes 24 to 27 by a user's turn-on / off operation, and inputs it to the control circuit 30. The dimming operation unit 32 inputs a dimming signal for adjusting the light amount of the light emitting diodes 24 to 27 to the control circuit 30 including a microcomputer.

  The control circuit 30 is driven by a power supply unit (not shown), and the switching transistor 17 is switched on and off by its operation to drive the switching transformer 16. The control circuit 30 includes a current control unit 301 and a voltage control unit 302.

  When a lighting instruction signal is input from the lighting / light-off instruction unit 31, the current control unit 301 compares a preset reference value (current value) with the detection signal of the current detection unit 29, and based on the comparison result. Thus, the on / off operation of the switching transistor 17 is controlled, and the current supplied to the light emitting diodes 24 to 27 is controlled to be constant. Further, the current control unit 301 changes the reference value in accordance with the dimming signal from the dimming operation unit 32, and the switching transistor 17 is turned on / off based on the changed reference value, and the light amounts of the light emitting diodes 24-27. Can be adjusted within a range of 0 to 100% of the rating, for example.

  When the turn-off instruction signal is input from the turn-on / off instruction unit 31, the voltage control unit 302 detects a preset reference value (voltage value lower than the lighting start voltage of the light emitting diodes 24 to 27) and the voltage detection unit 28. The switching transistor 17 is turned on and off based on the comparison result, and the voltage applied to the light emitting diodes 24 to 27 is controlled to a constant voltage lower than the lighting start voltage of the light emitting diodes 24 to 27. In this case, the constant voltage lower than the lighting start voltage of the light emitting diodes 24 to 27 is equal to or higher than the operating voltage of the control circuit 30 such as a microcomputer, and the constant voltage is not shown in the control circuit 30 even when the light emitting diodes 24 to 27 are turned off. Is supplied to the power supply unit.

  Next, the operation of the embodiment configured as described above will be described.

  The AC power of the AC power supply 11 is full-wave rectified by the full-wave rectifier circuit 13, smoothed by the ripple current smoothing capacitor 14, and supplied to the switching transformer 16 and the switching transistor 17.

  When the light emitting diodes 24 to 27 are turned on from this state, a lighting instruction signal is output from the lighting / extinguishing instruction unit 31 by a lighting operation of the user. This lighting instruction signal is input to the control circuit 30.

  The control circuit 30 causes the switching transistor 17 to be turned on and off by the current control unit 301 to drive the switching transformer 16. In this case, when the switching transistor 17 is turned on, a current is passed through the primary winding 16a of the switching transformer 16 to accumulate energy, and when the switching transistor 17 is turned off, the energy accumulated in the primary winding 16a is discharged through the secondary winding 16b. To do. As a result, a direct current output is generated via the rectifying and smoothing circuit 23, and the light emitting diodes 24 to 27 are turned on by the direct current output.

  The current flowing through the light emitting diodes 24 to 27 is detected by the current detection unit 29, and a detection signal corresponding to the detected current is input to the current control unit 301. The current control unit 301 compares a preset reference value (current value) with the detection signal of the current detection unit 29, controls the on / off operation of the switching transistor 17 based on the comparison result, and causes the light emitting diodes 24 to 27 to operate. The supplied current is controlled to be constant.

  Further, when a dimming signal is output from the dimming operation unit 32, the reference value is changed according to the dimming signal. The current control unit 301 turns on / off the switching transistor 17 based on the changed reference value. Thereby, the electric current which flows into the light emitting diodes 24-27 is changed, and the light quantity of the light emitting diodes 24-27 is adjusted in the range of 0-100% of ratings, for example.

  In this case, the light emitting diodes 24 to 27 are turned on at, for example, operating points A, B, and C on the VI characteristic curve of the light emitting diode shown in FIG. The Here, the current I1 is supplied to the light emitting diodes 24 to 27 at the operating point A, the current I2 at the operating point B, and the current I3 at the operating point C.

  When the light emitting diodes 24 to 27 are turned off from this state, a turn-off instruction signal is output from the turn-on / off instruction unit 31 by a user's turn-off operation. This turn-off instruction signal is input to the control circuit 30.

  The control circuit 30 compares the reference value preset by the voltage control means 302 (voltage value lower than the lighting start voltage of the light emitting diodes 24 to 27) with the detection signal of the voltage detection unit 28, and based on the comparison result. The switching transistor 17 is turned on and off, and the voltage applied to the light emitting diodes 24 to 27 is controlled to a constant voltage lower than the lighting start voltage of the light emitting diodes 24 to 27. In this case, in the VI characteristic curve of the light emitting diode shown in FIG. 4A, for example, the operating point A (or B, C) is moved to the operating point D, and the voltage applied to the light emitting diodes 24 to 27 emits light. The voltage is lowered to a constant voltage (V5 in the drawing) lower than the lighting start voltage of the diodes 24 to 27 (see FIG. 4B). As a result, the light emitting diodes 24 to 27 are extinguished in an energized state to which a constant voltage lower than the lighting start voltage is applied. In this case, even after the light emitting diodes 24 to 27 are turned off, a constant voltage lower than the lighting start voltage of the light emitting diodes 24 to 27 is supplied to a power supply unit (not shown) of the control circuit 30, and the control circuit 30 enters a standby state. Yes.

  Therefore, if this is done, the energy released through the secondary winding 16b of the switching transformer 16 when the switching transistor 17 is turned on and off is converted into a DC output by the rectifying and smoothing circuit 23, and the light emitting diodes 24 to 27 are converted by this DC output. It is a power supply device to be turned on, and when the light emitting diodes 24 to 27 are turned on, the current supplied to the light emitting diodes 24 to 27 is controlled to be constant according to the detection signal of the current detection unit 29, and the light emitting diodes 24 to 27 are turned off. In this case, the voltage applied to the light emitting diodes 24 to 27 by comparing the voltage value lower than the lighting start voltage of the light emitting diodes 24 to 27 set in advance as a reference value with the detection signal of the voltage detection unit 28 is determined. It is controlled to a constant voltage lower than the lighting start voltage of 24-27, and from this lighting start voltage There constant voltage so as to turn off the left light emitting diodes 24 to 27 energized applied. In this case, even if the light emitting diodes 24 to 27 are turned off, the power supply is not completely turned off, and the control system using the microcomputer such as the control circuit 30 continues to flow a small amount of current due to the operating voltage and is in a standby state. Therefore, after that, when a lighting instruction signal is output from the lighting / extinguishing instruction unit 31 by a user operation, the control circuit 30 immediately responds to the lighting instruction signal, and can quickly relight the light emitting diodes 24 to 27. it can. As a result, when the lighting diodes 24 to 27 of the light source are turned on and off, such as lighting fixtures that turn on and off the light source by detecting the presence or absence of a person, etc. Even when it is necessary to quickly start up the operation, it can be used as an optimal power supply device. Of course, it can be used not only for these lighting fixtures but also for a wide range of uses other than these.

  In addition, when the light emitting diodes 24 to 27 are turned on, the current flowing through the light emitting diodes 24 to 27 is controlled to be constant, so that even if the characteristics of the light emitting diodes vary, the light emitting diodes are substantially the same. Since brightness can be obtained, for example, even when a plurality of lighting fixtures are arranged, it is possible to suppress variations in brightness among the lighting fixtures, and there is a problem of impairing commerciality as a lighting fixture. can be solved.

  In addition, this invention is not limited to the said embodiment, In the implementation stage, it can change variously in the range which does not change the summary. For example, in the above-described embodiment, the voltage applied to the light emitting diodes 24 to 27 to turn off the light emitting diodes 24 to 27 is a constant voltage lower than the lighting start voltage of the light emitting diodes 24 to 27, and the control circuit 30 or the like. However, it may be less than the operating voltage of the microcomputer. Even in this case, since a slight preliminary current continues to flow through the control circuit 30, the subsequent operation can be quickly started up. In the above-described embodiment, the example of the light emitting diode is described as the semiconductor light emitting element. However, the present invention can be applied to the case where another semiconductor light emitting element such as a laser diode is used. In the above-described embodiment, the AC power supply 11 is described. However, the AC power supply 11 may be provided outside the apparatus.

  Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and is described in the column of the effect of the invention. If the above effect is obtained, a configuration from which this configuration requirement is deleted can be extracted as an invention.

The perspective view which shows the lighting fixture with which the power supply device concerning the 1st Embodiment of this invention is applied. Sectional drawing of the lighting fixture to which the power supply device concerning 1st Embodiment is applied. The figure which shows schematic structure of the power supply device concerning 1st Embodiment. The figure which shows the VI characteristic of the light emitting diode for demonstrating operation | movement of 1st Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Instrument body, 2 ... Light source part, 2a ... LED
DESCRIPTION OF SYMBOLS 3 ... Power supply room, 5 ... Power supply terminal room 11 ... AC power supply, 13 ... Full wave rectification circuit, 14 ... Capacitor 16 ... Switching transformer 17 ... Switching transistor, 23 ... Rectification smoothing circuit 24-27 ... Light emitting diode, 28 ... Voltage detection Unit 29 ... current detection unit, 30 ... control circuit 301 ... current detection unit, 302 ... voltage detection unit,
31: On / off instruction unit, 32 ... Dimming operation unit

Claims (4)

DC output generating means driven by the switching means and generating DC output from the AC power of the AC power source through the rectifying and smoothing means;
A semiconductor light emitting element which is turned on by a direct current output generated by the direct current output generation means;
Voltage control means for controlling a voltage applied to the semiconductor light emitting element by turning off the semiconductor light emitting element to be equal to or lower than a lighting start voltage of the semiconductor light emitting element;
A power supply device comprising: The voltage control unit is configured to reduce a voltage applied to the semiconductor light emitting element based on a comparison result between a preset voltage reference value and a voltage applied to the semiconductor light emitting element to a lighting start voltage of the semiconductor light emitting element or less. The power supply apparatus according to claim 1, wherein the power supply apparatus is controlled to a constant voltage. Current control means for controlling a current supplied to the semiconductor light emitting element to be constant based on a comparison result between a preset current reference value and a current supplied to the semiconductor light emitting element by turning on the semiconductor light emitting element The power supply device according to claim 1, further comprising: An illumination fixture comprising: the power supply device according to any one of claims 1 to 3; and an appliance main body having the power supply device.

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