JP2014220062A - Led illuminating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that when trying to lower an output voltage of a power storage section to an operating voltage of a microcomputer by means of a step-down converter, the step-down converter cannot operate as an input voltage lowers and approaches the output voltage, and the function of which stops, and since power cannot be supplied to the microcomputer, an LED unlights even if charges are still held in the power storage section.SOLUTION: Driving power of a microcomputer is generated by boosting a voltage of charges accumulated in a power storage section thereby continuing emission of light from an LED, and furthermore, by stepping down a power boosted for emitting light from the LED by means of a step-down converter.

Description

  The present invention relates to an LED lighting device that normally receives power from an external commercial power source to cause an LED to emit light, and that in the event of a power failure, continues to emit the LED with electric power from a built-in power storage unit.

  As an LED lighting apparatus as described above, a secondary battery is built in as a power storage unit, and in the state where power is supplied from an external commercial power source, the LED is caused to emit light by the power from the commercial power source. There has been proposed an LED lighting device in which a secondary battery is charged and LED emission is automatically continued by power stored in the secondary battery in the event of a power failure (for example, Patent Document 1 and Patent Document 1). 2).

  In these conventional LED lighting fixtures, the number of cells of the secondary battery is reduced in order to reduce the size of the secondary battery. However, if the number of cells of the secondary battery is reduced, the output voltage of the secondary battery decreases, and if the power from the secondary battery is supplied as it is to the built-in microcomputer, the microcomputer may not operate normally. Therefore, at the time of a power failure, the output voltage of the secondary battery is boosted for light emission of the LED, and boosted for operation of the microcomputer.

JP 2011-34977 A (Claim 1, paragraph 0028) JP 2009-54509 A (Claim 1, paragraph 0011)

  In the above-mentioned conventional one, the output voltage of the secondary battery is lower than the voltage necessary for operating the microcomputer, so that the voltage is boosted by a circuit such as a boost converter. When a double layer capacitor is used as a power storage unit, the charged voltage becomes higher than the operating voltage of the microcomputer. Then, in that case, it is necessary to lower the output voltage of the power storage unit to the operating voltage of the microcomputer by a step-down converter.

  However, in the step-down converter, when the input voltage decreases and approaches the output voltage, the operation becomes impossible and the function of the step-down converter stops. Then, although the electric charge is still held in the power storage unit, power cannot be supplied to the microcomputer, and the LED is also turned off.

  Therefore, in view of the above problems, the present invention provides an LED lighting apparatus that can effectively use the power stored in the power storage unit when supplying the output power of the step-down converter to the microcomputer. Let it be an issue.

  In order to solve the above-described problems, an LED lighting apparatus according to the present invention is an LED lighting apparatus that emits an LED using electric power supplied from an external commercial power source, and has a power storage unit that is charged by electric power from the commercial power source. In the case of a power failure, the voltage of the electric charge stored in the power storage unit is increased to continue the light emission of the LED, and the microcomputer has a microcomputer for controlling the light emission of the LED, and the power increased for the LED light emission at the time of the power failure Is further reduced by a step-down converter to generate power for driving the microcomputer.

  The step-down converter stops operating when the input voltage decreases and approaches the output voltage. On the other hand, in the case of a boost converter, if the input voltage decreases, the difference from the output voltage increases, so the operation does not stop halfway and the power stored in the power storage unit is output until it is used up with holon. Can continue. Accordingly, it is possible to continue supplying power to the microcomputer until the power stored in the power storage unit becomes almost zero.

  The above configuration is particularly effective when the power storage unit is an electric double layer capacitor.

  As is clear from the above description, the present invention once boosts the power of the power storage unit and then reduces the voltage by the step-down converter to operate the microcomputer, so that the power stored in the power storage unit can be used effectively. After the power failure, the time that the LED can continue to emit light can be extended.

The figure which shows the state of the LED lighting fixture embed | buried under the ceiling The perspective view which shows the shape of the whole LED lighting fixture Exploded perspective view of LED lighting fixture Block diagram of the circuit that operates during a power failure

  With reference to FIG. 1, 1 is the LED lighting fixture (henceforth a fixture) by this invention. The appliance 1 is embedded in the ceiling CL of the bathroom, and a plurality of LEDs (light emitting diodes) are attached to the lighting plate 2 facing the bathroom. And the inside of a bathroom is illuminated with the light emitted from each LED.

  With reference to FIG. 2, a terminal plate 12 is attached to the upper surface of the main body case 11 of the instrument 1, and a lamp line 13 for supplying power from an external commercial power source is connected to the terminal plate 12.

  Referring to FIG. 3, power supply unit 3 is housed in main body case 11 below terminal plate 12. This power supply unit 3 steps down the voltage of 100 volts supplied from an external commercial power supply and supplies it to the LED, and also includes a microcomputer for controlling the lighting of the LED, and also generates electric power for driving the microcomputer. doing.

  When an external illumination switch (not shown) is turned on, electric power is supplied from an external commercial power supply via the lamp line 13, and the LED mounted on the lower surface of the illumination plate 2 is turned on. If the power supply from the outside is stopped due to a power failure or the like when this light switch is on, if the LED turns off, especially if you are bathing at night, you can go out of the bathroom to the dressing room and wear clothes. It becomes difficult.

  Therefore, in the present invention, a power storage unit is provided in the appliance 1, and when a power failure or the like occurs, lighting is continued for a predetermined time with the power stored in the power storage unit. In this embodiment, an example in which an electric double layer capacitor is used as a power storage unit will be described.

  FIG. 4 shows an emergency circuit in which the LED 8 is turned on at the time of a power failure or the like by the electric power stored in the electric double layer capacitor 4 during normal energization. Therefore, a normal lighting circuit for lighting the LED 8 with power from an external commercial power supply is omitted.

  When a power failure detection circuit (not shown) detects that there is a power failure, the microcomputer 5 switches the lighting power source from the external power source to the electric double layer capacitor 4. As shown in the drawing, since the plurality of LEDs 8 are connected in series, it is necessary to apply a voltage obtained by multiplying the number of lighting voltages of one LED to both ends of the series circuit of the LEDs 8. Therefore, the voltage of the electric double layer capacitor 4 is boosted by the boost converter 6 and supplied to the LED 8. Then, the operation power of the microcomputer 5 is generated by the step-down converter 7 from the high voltage boosted by the step-up converter 6. In this way, once the voltage is raised by the boost converter 6 and then lowered by the step-down converter 7, the microcomputer 5 can continue to operate until the electric charge stored in the electric double layer capacitor 4 becomes almost zero. .

  The microcomputer 5 constantly monitors the voltage of the electric double layer capacitor 4 by the voltage detection circuit 41. When the stored electric power gradually decreases, the voltage across the electric double layer capacitor 4 decreases, so the microcomputer 5 can monitor the remaining amount of electric power stored in the electric double layer capacitor 4.

  All the LEDs 8 are turned on in a state where the amount of electricity stored in the electric double layer capacitor 4 is sufficient. However, the illuminance is lowered and the rate of reduction in the amount of electricity stored in the electric double layer capacitor 4 is suppressed compared to the case where it is turned on by external power. Specifically, in the case of emitting light with power from an external power source, if the current of the LED 8 is 300 mA, the power is reduced to 50 mA at the time of a power failure or the like. This reduction in current is performed by the transistor 51 connected in series with the LED 8, and the operation of the transistor 51 is controlled by the microcomputer 5.

  When the amount of electricity stored in the electric double capacitor 4 decreases, all LEDs 8 cannot be lit continuously. If left as it is, all the LEDs 8 are turned off at the same time. Therefore, when the voltage across the electric double layer capacitor 4 is lowered to the preset first reference voltage, the microcomputer 5 turns on the transistor 91 to turn on a part (this embodiment). In the embodiment, two LEDs) are short-circuited and turned off, and the remaining LEDs 8 are turned on to suppress power consumption.

  When the voltage across the electric double layer capacitor 4 further decreases to the second reference voltage in this state, the number of LEDs 8 that are turned off is increased by turning on the transistor 92, that is, the number of LEDs 8 that are turned on is reduced, thereby further reducing power consumption. It was decided. When the voltage across the terminals further decreases to the third reference voltage, the transistor 93 is turned on to finally turn on only one LED 8.

  Thus, when power supply from the outside stops like a power failure, the current of the LED 8 is suppressed and the number of the LEDs 8 that are lit in stages is reduced, so that even if the illuminance is small, it takes a long time. LED8 can be kept on.

  In addition, although the said embodiment demonstrated the case where the instrument 1 was attached to the bathroom, an installation place is not limited to a bathroom, For example, it is clear that it may install in other places, such as a corridor of a building. .

  As described above, the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 LED lighting fixture 2 Illumination board 3 Power supply part 4 Electric double layer capacitor 8 LED

Claims (2)

  An LED luminaire that emits LEDs with electric power supplied from an external commercial power source, and has a power storage unit that is charged with power from the commercial power source, and boosts the voltage of the electric charge stored in the power storage unit in the event of a power failure In order to continue LED light emission, it has a microcomputer that controls LED light emission, and in the event of a power failure, the power raised for LED light emission is further stepped down by a step-down converter to generate driving power for the microcomputer LED lighting fixture characterized by doing. 2. The LED lighting apparatus according to claim 1, wherein the power storage unit is an electric double layer capacitor.

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