JP4199201B2 - Power supply device and lighting device - Google Patents

Power supply device and lighting device Download PDF

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JP4199201B2
JP4199201B2 JP2005036271A JP2005036271A JP4199201B2 JP 4199201 B2 JP4199201 B2 JP 4199201B2 JP 2005036271 A JP2005036271 A JP 2005036271A JP 2005036271 A JP2005036271 A JP 2005036271A JP 4199201 B2 JP4199201 B2 JP 4199201B2
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current
voltage
output
led
resistor
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JP2006222376A (en
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雅弘 小川
安夫 川野
武彦 斉藤
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星和電機株式会社
株式会社共進電機製作所
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02BCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00Energy efficient lighting technologies
    • Y02B20/40Control techniques providing energy savings
    • Y02B20/46Control techniques providing energy savings based on detection of the illumination level

Description

  The present invention relates to a power supply device that supplies current to an LED and a lighting device including the power supply device.

  Compared to fluorescent lamps that have been used as light sources, LEDs (Light Emitting Diodes) are attracting attention as light sources because of their low power consumption and long life. Comparisons of tens to hundreds of mA LEDs capable of flowing a large current have been widely used not only for indoor lighting equipment but also for road lighting equipment, industrial lighting equipment, and the like.

  When such an LED is used as a light source for a lighting device, a plurality of LEDs are connected as an aggregate and arranged in the device in order to ensure the amount of light emitted from the lighting device (for example, a plurality of LEDs are connected in series). Connect a constant voltage power supply to the LED as an assembly, apply a constant voltage to the LED, and connect a limiting resistor in series with the LED to set the current flowing through the LED to a predetermined value. Therefore, a power supply device that limits current is used.

  FIG. 4 is a block diagram showing the configuration of a conventional LED power supply device. In the figure, reference numeral 1 denotes a commercial power source for inputting an AC voltage to the power supply device. The filter circuit 2 removes noise flowing from the commercial power source 1. The rectifier circuit 3 performs full-wave rectification on the input AC voltage. Capacitor 4 smoothes the voltage waveform that has been full-wave rectified by rectifier circuit 3, and outputs a substantially constant DC voltage to converter circuit 10. The converter circuit 10 includes a constant voltage control unit and outputs a predetermined constant voltage. The LEDs 9, 9,... Connected in series are connected to the output side of the converter circuit 10 through a current limiting resistor 20.

  As a result, a current obtained by dividing a voltage obtained by subtracting a voltage corresponding to a forward voltage drop of each LED from the output voltage of the converter circuit 10 by each LED flows through each LED, and each LED has a predetermined brightness. It lights up.

  However, in the conventional power supply apparatus, the output voltage of the converter circuit 10 is controlled so as to be always constant. On the other hand, the forward voltage of the LED varies depending on the elapsed lighting time of the LED, the ambient temperature, and the like. For this reason, for example, when the ambient temperature of the LED rises, a drop in the forward voltage of each of the LEDs connected in series is superimposed, so the voltage applied to the limiting resistor rises and the current flowing through the LED To increase. For this reason, when the ambient temperature changes, the brightness of the LED changes, the power consumed by the limiting resistor increases, the heat generated by the power supply increases, and the efficiency of the power supply decreases. was there. Such a problem becomes more prominent as the number of LEDs connected in series increases.

The present invention has been made in view of such circumstances, and by providing a comparison unit that detects a current supplied to the LED and compares a current corresponding to the detected current with a threshold current, the comparison result is obtained. Based on changing the output voltage and making the current supplied to the LEDs substantially constant, regardless of the number of LEDs connected in series, even if the lighting time or ambient temperature has changed, An object of the present invention is to provide a power supply device that can suppress variations in brightness of LEDs and prevent an increase in heat generation and a decrease in efficiency, and a lighting device including the power supply device.

  Another object of the present invention is to provide a power supply apparatus capable of preventing an output voltage from rising abnormally in a no-load state in which an LED is not connected by providing a voltage detection unit that detects an output voltage. It is providing the illuminating device provided with this power supply device.

A power supply apparatus according to a first aspect of the present invention is a power supply apparatus for supplying current to an LED, wherein the output voltage variable voltage supply section for supplying current to the LED, and a first resistance element connected in series to the LED A current output unit that outputs a current according to a current supplied to the LED based on a voltage obtained by conversion by the first resistance element, a cathode terminal, an anode terminal, and a reference voltage One end of each of the second resistor element and the third resistor element is connected to a reference voltage terminal of a reference voltage setting element having a terminal, and a threshold value setting unit for setting a threshold current is provided. A fourth resistor element and a light emitting diode, each having an output end connected to the other end of the second resistor element, and connected in series between the cathode terminal of the reference voltage setting element and the output end of the current output unit And the reference voltage setting A series circuit of a child, the second Yes connected between the resistance element and the third resistive element each of the other end, further a comparison unit for comparing the current and the threshold current the current output section has an output The voltage supply unit includes a phototransistor that receives light emitted from the light emitting diode of the series circuit, and the control unit changes an output voltage according to a current flowing through the phototransistor so that a current flowing through the LED is substantially constant. It is characterized by being made.

Power supply according to the second invention, when Oite the first shot bright, includes a voltage detector for detecting the output voltage, the voltage detecting section the voltage detected, which exceeds a predetermined threshold voltage, the The output voltage of the voltage supply unit is lowered.

Lighting device according to a third invention is characterized by comprising a LED, a power supply device according to the first or second aspect of the present invention.

In the first invention and the third invention, a current that outputs a current corresponding to the current supplied to the LED based on the voltage obtained by converting the current supplied to the LED by the first resistance element. The output end of the output unit is connected to the other end of the second resistance element. Since one end of the second resistance element is connected to one end of the third resistance element and to the reference voltage terminal of the reference voltage setting element, the second resistance element and the third resistance The current flowing through the element is set to a value obtained by dividing the reference voltage of the reference voltage setting element by the resistance value of the third resistance element (threshold current corresponding to the target value of the current flowing through the LED). Between the other ends of the second resistor element and the third resistor element, the reference voltage setting element and a fourth resistor element having one end connected to the anode terminal or the cathode terminal of the reference voltage setting element And a series circuit of light emitting diodes are connected.

When the current supplied to the LED increases, the current output from the current output unit increases. Since the current exceeding the threshold current does not flow through the second resistance element and the third resistance element, the threshold current is exceeded in the series circuit of the reference voltage setting element, the fourth resistance element, and the light emitting diode . Current flows. Due to the current flowing through the series circuit, the output voltage of the voltage supply unit is lowered by the current flowing through the phototransistor that receives light emitted from the light emitting diode, and the current supplied to the LED is reduced.

On the other hand, when the current supplied to the LED decreases, the current output from the current output unit decreases, and when the current falls below the threshold current, the series circuit of the reference voltage setting element, the fourth resistance element, and the light emitting diode There is no current flowing through. Since no current flows through the series circuit, no current flows through the phototransistor , so that the output voltage of the voltage supply unit is increased and the current supplied to the LED is increased. Thereby, the current supplied to the LED is set to a value substantially equal to the target value.

In the second invention, when the output voltage detected by the voltage detection unit exceeds a predetermined threshold voltage, the output voltage of the voltage supply unit is lowered to the predetermined threshold voltage.

In the first and third inventions, one end of the second resistance element is connected to one end of the third resistance element with the other end grounded, and the reference voltage terminal of the reference voltage setting element is connected to the one end. A threshold value setting unit; and a comparison unit having a series circuit of a light emitting diode and a fourth resistance element having one end connected to the anode end or the cathode end of the reference voltage setting element and the reference voltage setting element. By controlling the output voltage of the voltage supply unit according to the current flowing in the phototransistor that receives the light emitted from the light emitting diode according to the presence or absence of the current flowing in the circuit, current control can be performed with a relatively simple configuration. Thus, it is possible to always supply a substantially constant current to the LEDs, and to suppress fluctuations in the brightness of the LEDs caused by time changes, temperature changes, etc., regardless of the number of LEDs connected in series. It can be. Further, even when a short circuit breakage occurs in the LED and the load greatly fluctuates, it is possible to always supply a substantially constant current to the LED, prevent an excessive current from flowing through the LED, and improve reliability. . Further, since it is not necessary to use a limiting resistor, heat generation and power consumption caused by the limiting resistor can be eliminated, and wasteful power consumption can be reduced to increase efficiency.

In the second aspect of the invention, when the output voltage detected by the voltage detector exceeds a predetermined threshold voltage, the output voltage is abnormally increased when there is no load by reducing the output voltage of the voltage supply unit. Can be prevented.

  Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof. FIG. 1 is a block diagram showing a configuration of a lighting device according to the present invention, and FIG. 2 is a circuit diagram showing a configuration of a power supply device according to the present invention. The lighting device includes a power supply device and a plurality of LEDs 9, 9,... Connected in series on the output side of the power supply device. A commercial power source 1 is connected to the input side of the power supply device.

  In the figure, 2 is a filter circuit. The filter circuit 2 blocks noise flowing from the commercial power source 1. The rectifier circuit 3 is a full-wave rectifier circuit composed of a diode bridge, and full-wave rectifies the input AC voltage, and outputs the full-wave rectified DC voltage to the capacitor 4. The capacitor 4 smoothes the DC voltage input from the rectifier circuit 3 and outputs a substantially constant DC voltage to the converter circuit 5.

  The converter circuit 5 includes a primary winding and a secondary winding, and a drain is connected to one end of the primary winding of the transformer 52 and a transformer 52 for stepping down the input DC voltage to a predetermined DC voltage. The FET 53 that performs a switching operation at a predetermined oscillation frequency (for example, 40 kHz) and the PWM control unit 51 that outputs a drive signal to the gate of the FET 53 via the output terminal DR in order to control the switching operation of the FET 53. The current flowing between the drain and the source of the FET 53 is detected, the detected current is converted into a voltage and output to the sense terminal IS of the PWM controller 51, and the current of each period of the PWM controller 51 is controlled. And a resistor 54 having one end connected to the source of the FET 53 and the other end grounded, and a control for stopping the oscillation of the FET 53 and shifting to the intermittent oscillation mode. Comprising Nos a phototransistor 55a to be outputted to the PWM control unit 51 via the feedback end FB, and 55b. That is, the PWM control unit 51 stops outputting the drive signal that drives the switching operation of the FET 53 while either the phototransistor 55a or the phototransistor 55b is on.

  The current detection circuit 6 includes a resistor 61. The resistor 61 is connected in series to the LEDs 9, 9,..., One end of the resistor 61 is connected to the constant current control circuit 7, and the other end is a converter. It is connected to one end of the secondary winding of the circuit 5. The one end of the secondary winding is grounded. As a result, a voltage obtained by integrating the resistance value of the resistor 61 to the current If flowing through the LEDs 9, 9... Is output to the constant current control circuit 7.

  The constant current control circuit 7 includes an operational amplifier 71, and the one end of the resistor 61 of the current detection circuit 6 is connected to the non-inverting input terminal of the operational amplifier 71 through a resistor 79. A resistor 72 is connected between the inverting input terminal and the output terminal of the operational amplifier 71, and a resistor 73 is connected between the inverting input terminal of the operational amplifier 71 and the ground. As a result, the current If detected by the resistor 61 is converted into a voltage, input to the non-inverting input terminal of the operational amplifier 71, and the operational amplifier 71 according to the amplification degree determined by the resistance values of the resistors 72 and 73. Operates as a positive phase amplifier and outputs a voltage Vo to the output terminal.

The constant current control circuit 7 has a resistor 74 and a resistor 75 connected in series between the output terminal of the operational amplifier 71 and the ground, and a reference voltage terminal connected to a connection point between the resistor 74 and the resistor 75, and an anode terminal. A ground shunt regulator 78 (reference voltage setting element), and a resistor 77 and a light emitting diode 76b connected in series between the output terminal of the operational amplifier 71 and the cathode terminal of the shunt regulator 78. As a result, the resistors 74 and 75 can be set so that a set current Ir (threshold current) having a value obtained by dividing the voltage Vr of the reference voltage terminal of the shunt regulator 78 by the resistance value of the resistor 75 is always supplied.

When the voltage Vo at the output terminal of the operational amplifier 71 rises and the current Io output from the output terminal exceeds the set current Ir, the surplus current Ie (Io−Ir) that exceeds the set current Ir 77, the light-emitting diode 76b and the shunt regulator 78 flow in series. When a current flows through the light-emitting diode 76b, the phototransistor 55b is turned on. On the other hand, when the voltage Vo at the output terminal of the operational amplifier 71 decreases and the current Io output from the output terminal becomes equal to or lower than the set current Ir, the surplus current Ie is present in the series circuit of the resistor 77 and the shunt regulator 78. Since the current does not flow and the current does not flow to the light emitting diode 76b, the phototransistor 55b is turned off.

Between the output terminals of the converter circuit 5, a resistor 81, a light emitting diode 82a, and a Zener diode 83 are connected in series. When the output voltage of the converter circuit 5 exceeds the threshold voltage set by the Zener diode 83, a current flows through the light emitting diode 82a, turning on the phototransistor 55a. Further, when the output voltage of the converter circuit 5 becomes equal to or lower than the threshold voltage, no current flows through the light emitting diode 82a, and the phototransistor 55a is turned off. Thereby, when the output voltage of the converter circuit 5 rises abnormally in a no-load state or the like, the oscillation operation of the FET 53 can be stopped and the output voltage of the converter circuit can be lowered.

  Next, the operation of the power supply device of the present invention will be described. By applying an AC voltage to the input terminal of the power supply device, the PWM control unit 51 causes a drive signal having a predetermined oscillation frequency (for example, 40 kHz) and pulse width (for example, a duty ratio of 50%) to be output from the output terminal DR to the FET 53. The FET 53 performs a switching operation. As a result, the converter circuit 5 outputs a predetermined output voltage and supplies a direct current to the LEDs 9, 9,... Connected in series.

  The PWM control unit 51 converts the current flowing between the drain and source of the FET 53 into a voltage by the resistor 54, acquires the converted voltage at the sense terminal IS, and performs current control according to the acquired voltage. Thereby, an overcurrent protection circuit can be set for each period.

  The resistor 61 of the current detection circuit 6 detects the current If flowing through the LEDs 9, 9,..., Converts the detected current If into a voltage, and outputs the voltage to the non-inverting input terminal of the operational amplifier 71. The operational amplifier 71 outputs a voltage Vo obtained by amplifying the input voltage with a predetermined amplification factor from the output terminal.

  When the ambient voltage of the LEDs 9, 9,... Rises, the forward voltage Vf of each of the LEDs 9, 9,... Decreases, for example, from 3.5V to 3.0V, the output voltage of the converter circuit 5 is constant. Therefore, the current If flowing through the LEDs 9, 9,... Increases. When the current If increases, the voltage input to the non-inverting input terminal of the operational amplifier 71 also increases, and the voltage Vo at the output terminal of the operational amplifier 71 increases.

When the voltage Vo at the output terminal rises, the current Io output from the output terminal also increases. When the current Io exceeds the set current Ir, the surplus current Ie (Io-Ir) becomes the resistor 77, the light emitting diode 76b, the shunt regulator. The phototransistor 55b is turned on by a current Ie flowing through 78 and flowing through the light emitting diode 76b. As a result, the feedback terminal FB of the PWM control unit 51 becomes the LOW level, the drive signal output to the gate of the FET 53 is stopped, and the mode is shifted to the intermittent oscillation mode in which the oscillation operation of the FET 53 is temporarily stopped.

  When the oscillation operation of the FET 53 is stopped, the output voltage of the converter circuit 5 is lowered, and the current If flowing through the LEDs 9, 9,. Thereby, even if it is a case where forward voltage Vf of LED9, ... is reduced by change of ambient temperature etc., the increase in the current If can be suppressed.

On the other hand, when the current If decreases, the voltage input to the non-inverting input terminal of the operational amplifier 71 also decreases, and the voltage Vo at the output terminal of the operational amplifier 71 decreases. When the voltage Vo at the output terminal decreases, the current Io output from the output terminal decreases, and when the current Io becomes equal to or less than the set current Ir, the surplus current Ie becomes zero and the current Ie does not flow through the light emitting diode 76b. . For this reason, the phototransistor 55b is turned off. As a result, the feedback terminal FB of the PWM control unit 51 becomes HIGH level, and the stopped drive signal is output to the gate of the FET 53, and the converter circuit 5 shifts from the intermittent oscillation mode to the normal oscillation mode.

  When the oscillation operation of the FET 53 is performed, the output voltage of the converter circuit 5 increases, and the current If flowing through the LEDs 9, 9,. Thereby, it is possible to suppress a decrease in the current If and to supply a substantially constant current If to the LEDs 9, 9,.

  FIG. 3 is a time chart showing changes in the current If flowing in the LEDs 9, 9,. As shown in the figure, it is assumed that the current If, which was the target value at the beginning, starts to increase at a time point t1 due to a temperature change, a load change, and the like. Until the time t1, the FET 53 operates in the normal oscillation mode.

The current detection circuit 6 that has detected an increase in the current If at time t1 outputs a voltage converted from the detected current to the operational amplifier 71 of the constant current control circuit 7. The operational amplifier 71 outputs a voltage Vo corresponding to the input voltage. When the surplus current Ie flows to the light emitting diode 76b by the voltage Vo, the FET 53 temporarily stops the oscillation operation and shifts to the intermittent oscillation mode.

By stopping the oscillating operation of the FET 53, the output voltage of the converter circuit 5 decreases, and the current If that has increased starts to decrease. The current detection circuit 6 that detects the decrease in the current If outputs a voltage converted from the detected current to the operational amplifier 71 of the constant current control circuit 7. The operational amplifier 71 outputs a voltage Vo corresponding to the input voltage. When the voltage Vo decreases and the surplus current Ie does not flow to the light emitting diode 76b (time t2), the FET 53 starts an oscillation operation and shifts to the normal oscillation mode. The output voltage of the converter circuit 5 rises, the current If starts to increase, and reaches a predetermined target value.

  As described above, even when forward voltage fluctuations or load fluctuations of the LEDs 9, 9,... Occur due to changes in the ambient temperature, the current If flowing through the LEDs 9, 9,. be able to.

As described above, in the present invention, the current flowing through the LEDs 9, 9,... Is detected by the resistor 61, the detected current is converted into a voltage and output to the operational amplifier 71 according to the input voltage. The voltage Vo is output by the operational amplifier 71, and the current Io output from the operational amplifier 71 according to the voltage Vo is compared with the set current Ir flowing through the resistors 74 and 75. When the current Io exceeds the set current Ir, the surplus current Ie (Io−Ir) is passed through the series circuit of the resistor 77, the light emitting diode 76b, and the shunt regulator 78, and the drive signal that the PWM control unit 51 outputs to the gate of the FET 53 Is stopped, the output voltage of the converter circuit 5 is lowered and the current If is reduced.

On the other hand, when the current Io is equal to or less than the set current Ir, the surplus current Ie does not flow through the light emitting diode 76b, and the PWM control unit 51 outputs a drive signal output to the gate of the FET 53, whereby the output of the converter circuit 5 is output. Increase the voltage and increase the current If. This maintains the current If flowing in the LEDs 9, 9, etc. at a substantially constant target value even when forward voltage fluctuations or load fluctuations of the LEDs 9, 9, etc. occur due to changes in the ambient temperature. Can do.

  As a result, it is possible to pass a substantially constant current to the LED regardless of the number of LEDs connected in series with a relatively simple configuration. Therefore, the brightness and brightness of the LED generated based on time change and temperature change can be reduced. Variations can be suppressed. Further, even when a short circuit breakage occurs in the LED and the load greatly fluctuates, a substantially constant current can always flow through the LED, and an excessive current can be prevented from flowing through the LED, improving reliability. Further, since it is not necessary to use a limiting resistor as in the prior art, heat generation and power consumption caused by the limiting resistor can be eliminated, and wasteful power consumption can be reduced to increase efficiency.

In the present invention, when the output voltage of the converter circuit 5 exceeds the threshold voltage set by the Zener diode 83, a current flows through the light emitting diode 82a, and the phototransistor 55a is turned on. Thereby, when the output voltage of the converter circuit 5 rises abnormally in a no-load state or the like, the oscillation operation of the FET 53 can be stopped and the output voltage of the converter circuit 5 can be lowered.

  In the above-described embodiment, the power supply device is configured to include the rectifier circuit 3. However, the power supply device is not limited to this, and a DC voltage supplied by a battery is input instead of an AC voltage as an input voltage. It may be configured to. In this case, the rectifier circuit 3 and the capacitor 4 are not necessary. The converter circuit 5 is not limited to the step-down type, and may be a step-up type or a step-up / down type.

  In the above-described embodiment, the converter circuit 5 is configured to change the output voltage by changing the pulse width of the PWM method. However, the present invention is not limited to this. For example, the converter circuit 5 is a VCO (Voltage Controlled Oscillator). As long as the output voltage can be varied, such as a voltage-controlled oscillator), any configuration may be used.

  In the above embodiment, a plurality of LEDs are connected in series. However, the number of LEDs is not particularly limited, and may be one. In addition, since the fluctuation | variation of the forward voltage of each LED is added, so that there are many LED, it can be said that the effect by this invention appears more notably. In addition, a current driving element such as an organic EL element can be used as a load instead of the LED.

  In the above-described embodiment, the voltage converted from the current If by the resistor 61 is output to the operational amplifier 71 that operates as a positive phase amplifier. However, the operational amplifier 71 operates as a negative phase amplifier. May be. In this case, a signal obtained by inverting the output of the phototransistor 55 b can be output to the PWM control unit 51.

  In the above-described embodiment, the resistors 61, 72, 73, 74, 75, and 77 are configured as one resistor. However, each resistor is not limited to one resistor, and a plurality of resistors are connected in series. Or it may be a group of resistors connected in parallel. Moreover, the structure using a variable resistance may be sufficient. The resistor 77 may be connected to the anode side instead of the cathode side of the shunt regulator 78.

It is a block diagram which shows the structure of the illuminating device which concerns on this invention. It is a circuit diagram which shows the structure of the power supply device which concerns on this invention. It is a time chart which shows the change of the electric current which flows into LED. It is a block diagram which shows the structure of the power supply device for conventional LED.

Explanation of symbols

5 Converter circuit 6 Current detection circuit 7 Constant current control circuit 8 Voltage detection circuit 9 LED
51 PWM controller 53 FET
55a, 55b Phototransistor 61 Resistor 71 Operational amplifier 72, 73, 74, 75, 77 Resistor 76b Light emitting diode 78 Shunt regulator 81 Resistor 82a Light emitting diode 83 Zener diode

Claims (3)

  1. In a power supply for supplying current to an LED,
    An output voltage variable voltage supply unit for supplying current to the LED;
    A first resistor element connected in series to the LED, and a current that outputs a current corresponding to the current supplied to the LED based on the voltage obtained by conversion by the first resistor element An output section;
    One end of each of the second resistance element and the third resistance element is connected to a reference voltage terminal of a reference voltage setting element having a cathode terminal, an anode terminal, and a reference voltage terminal, and sets a threshold current. And
    An output end of the current output unit is connected to the other end of the second resistance element;
    A series circuit of a fourth resistor element and a light emitting diode connected in series between the cathode terminal of the reference voltage setting element and the output terminal of the current output unit, and the reference voltage setting element includes the second resistor. A comparison unit that is connected between the other end of each of the element and the third resistance element, and that compares the current output from the current output unit with the threshold current;
    The voltage supply unit
    A phototransistor that receives light emitted by the light emitting diode of the series circuit;
    A power supply apparatus, wherein a control unit changes an output voltage by a current flowing through the phototransistor so that a current flowing through the LED is substantially constant.
  2. A voltage detection unit for detecting the output voltage;
    The power supply apparatus according to claim 1, wherein when the voltage detected by the voltage detection unit exceeds a predetermined threshold voltage, the output voltage of the voltage supply unit is lowered.
  3.   An illumination device comprising: an LED; and the power supply device according to claim 1 for supplying an electric current to the LED.
JP2005036271A 2005-02-14 2005-02-14 Power supply device and lighting device Active JP4199201B2 (en)

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JP2006288945A (en) * 2005-04-14 2006-10-26 Pentax Corp Voltage control circuit of endoscope device
JP3981698B1 (en) * 2006-12-18 2007-09-26 株式会社モモ・アライアンス Lighting device
KR100862507B1 (en) * 2007-06-20 2008-10-08 삼성전기주식회사 Device for driving led
KR100897819B1 (en) 2007-06-21 2009-05-18 주식회사 동부하이텍 Circuit for driving Light Emitted Diode
WO2009028863A2 (en) * 2007-08-27 2009-03-05 Inix Co., Ltd. Method and apparatus for thermal control of led device
JP4881275B2 (en) * 2007-10-17 2012-02-22 株式会社エーダブリュ・ジャパン LED lighting drive device
JP5138424B2 (en) * 2008-03-04 2013-02-06 シャープ株式会社 Control method and control apparatus for organic EL device
JP5324817B2 (en) * 2008-05-09 2013-10-23 パナソニック株式会社 LED drive device, vehicle lighting device
US7936132B2 (en) * 2008-07-16 2011-05-03 Iwatt Inc. LED lamp
JP2010050336A (en) * 2008-08-22 2010-03-04 Nec Lighting Ltd Power supply apparatus for light-emitting element
WO2010047433A1 (en) * 2008-10-25 2010-04-29 Ki Ho Nam Driving circuit for an ultra-bright led lamp
JP5153578B2 (en) * 2008-11-05 2013-02-27 株式会社エーダブリュ・ジャパン LED lighting device
WO2010106897A1 (en) * 2009-03-18 2010-09-23 Semiconductor Energy Laboratory Co., Ltd. Lighting device
JP5333769B2 (en) * 2009-09-04 2013-11-06 東芝ライテック株式会社 LED lighting device and lighting device
KR101704018B1 (en) * 2009-11-17 2017-02-07 엘지이노텍 주식회사 Apparatus for driving Light Emitting Diode
JP5009357B2 (en) * 2009-12-24 2012-08-22 星和電機株式会社 Power supply device and lighting device
JP5051862B1 (en) * 2011-03-18 2012-10-17 株式会社ソディック Straight tube type light emitting diode lighting
JP2014002867A (en) * 2012-06-15 2014-01-09 Panasonic Corp Lighting device and illuminating fixture
KR101464916B1 (en) * 2014-03-31 2014-11-25 이상범 High-efficiency airfield lighting power supply and light control system.

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