JP2017027901A - LED lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that power supply stops entirely upon occurrence of power failure when power failure is detected using a comparator, and since the reference voltage itself disappears, power of a backup power supply must be used for creating the reference voltage, but the time for lighting an LED is shortened, when the power charging the backup power supply is used for creating the reference voltage.SOLUTION: An LED lighting device includes a power supply unit receiving power from a commercial power supply regardless of on/off of a lighting and unlighting switch, and outputting a DC power of primary voltage from the commercial power, while charging a backup power supply, a constant current control unit for lighting the LED by boosting the DC power of primary voltage, and a power failure detector for continuing the lighting of the LED, by turning a switching element ON when the DC power of primary voltage, outputted from the power supply unit is lost, and supplying the DC power charging the backup power supply to the constant current control unit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an LED lighting device that uses an LED as a light emission source, lights the LED with power from an external commercial power source, and lights the LED continuously during a power failure.

  In the conventional LED lighting device of this type, since the power supply from the outside is stopped at the time of a power failure, a backup power source that charges while the power from the outside is supplied is provided. And if the power failure detection part which detects generation | occurrence | production of a power failure is detected and the power failure detection part detects generation | occurrence | production of a power failure, lighting of LED will be continued with the electric power currently charged by backup power supply.

  In this way, it is necessary to detect the occurrence of a power failure. For this detection, for example, a comparator is used to determine that a power failure has occurred when the voltage on the power supply side drops below a certain value. (For example, refer to Patent Document 1).

JP 2012-226886 A (paragraph 0025)

  The comparator used for the power failure detection inputs a reference voltage and a monitored voltage, and inverts the output by comparing both voltages. Therefore, the conventional LED lighting device also compares the reference voltage with the voltage from the power source, and determines that a power failure has occurred when the voltage from the power source drops below the reference voltage. Yes.

  However, since all power supply stops when a power failure occurs, the reference voltage itself disappears. Therefore, the power of the backup power source must be used to create the reference voltage. However, although the backup power supply is for lighting the LED at the time of a power failure, if the charged power is used for generating the reference voltage, there is a problem that the time for lighting the LED is shortened. .

  Therefore, in view of the above problems, the present invention provides an LED lighting device that can detect the occurrence of a power failure without using a comparator and can use all of the power charged in the backup power source for lighting the LEDs. Is an issue.

  In order to solve the above problems, an LED lighting device according to the present invention is an LED lighting device that turns on an LED with electric power from an external commercial power source, and an on / off switch for turning on and off provided between the commercial power source and the LED lighting device is provided. Regardless of the power supplied from the commercial power source, the primary voltage DC power is output from the commercial power and the backup power source is charged, and the primary voltage DC power is boosted to turn on the LED. When the DC power of the primary voltage output from the current control unit and the power supply unit disappears, the switching element is turned on to supply the DC power charged in the backup power source to the constant current control unit, and the LED is lit And a power failure detection unit that continues the operation.

  Using a switching element such as an FET (field effect transistor), the backup power source is normally shut off from the constant current control unit by this switching element, but triggered by the disappearance of the DC power of the primary voltage, The power of the backup power supply is supplied to the constant current control unit by turning on the switching element with the trigger.

  The above configuration is suitable for the case where the backup power source is an electric double layer capacitor.

  As is clear from the above description, the present invention turns on the switching element using the disappearance of the DC power of the primary voltage as a trigger, so that the reference voltage for comparison is set as in the conventional configuration using a comparator. There is no need to generate. Therefore, since it is not necessary to use the power of the backup power source to detect the occurrence of a power failure, all of the power charged in the backup power source can be used for lighting the LEDs.

The block diagram which shows the structure of the LED lighting apparatus by this invention Circuit diagram showing specific configuration of power failure detection unit

  Referring to FIG. 1, reference numeral 1 denotes an external commercial power supply that supplies 100 volt AC power. AC power is input to the switch detection circuit 2 from the commercial power supply 1 through the wall switch 11 for turning on and off. Since AC power from the commercial power source 1 is input to the switch detection circuit 2 when the wall switch 11 is in the on state, the switch detection circuit 2 can detect that the wall switch 11 is turned on. When the supply of AC power to the switch detection circuit 2 is stopped, it is determined that the wall switch 11 is turned off.

  Reference numeral 3 denotes a power supply unit, which is wired so that AC power from the commercial power supply 1 is supplied regardless of whether the wall switch 11 is on or off. The power supply unit 3 rectifies 100 volt AC power from the commercial power source 1 and converts it into DC power of the primary voltage (VA). The primary voltage VA is 12 volts, for example. The power supply unit 3 charges a backup power supply 31 composed of an electrolytic double layer capacitor. Note that the voltage charged in the backup power supply 31 is VE.

  The DC power of the primary voltage VA is input to the constant current control unit 4. The constant current control unit 4 boosts the input DC power of about 12 volts to about 18 volts and supplies the LED 5 with a constant current for lighting the LED 5 with a predetermined illuminance. In addition, in the state where the commercial power source 1 is operated and the supply of AC power is continued, the LED 5 is turned on / off by turning on / off the wall switch 11.

  When the supply of AC power from the commercial power supply 1 is stopped, that is, when a power failure occurs, the LED 5 is turned on with the power charged in the backup power supply 31 regardless of whether the wall switch 11 is on or off. The occurrence of a power failure is detected by the power failure detection unit 6. When a power failure occurs, the power failure detection unit 6 supplies power charged in the backup power source 31 to the constant current control unit 4. A specific configuration of the power failure detection unit 6 is shown in FIG.

  In the state where the DC power source of the primary voltage VA is generated, the FET 62 is turned on, so that the transistor 63 is turned off. When the transistor 63 is off, the switching element FET 61 is turned off, and the backup power supply 31 (VE) is isolated from the constant current control unit 4.

When a power failure occurs, the supply of DC power of the primary voltage is stopped, so VA becomes zero. Then, the FET 62 is turned off. At this time, since the voltage VE of the backup power supply 31 is alive, the transistor 63 is turned on, and as a result, the FET 61 that is the switching element is turned on. Then, since the backup power supply 31 is connected to the constant current control unit 4, the power charged in the backup power supply 31 flows to the constant current control unit 4 to light the LED 5.
In the above embodiment, an electrolytic double layer capacitor is used for the backup power supply 31. However, since the electrolytic double layer capacitor has a relatively low withstand voltage, the electric power of about 18 volts necessary for lighting the LED 5 cannot be charged. Therefore, the DC power of the primary voltage (VA) close to the charging voltage of the backup power supply 31 is generated, and the constant current control unit 4 is configured to boost the voltage to about 18 volts.

  In addition, this invention is not limited to an above-described form, You may add a various change in the range which does not deviate from the summary of this invention.

DESCRIPTION OF SYMBOLS 1 Commercial power supply 2 Switch detection circuit 3 Power supply part 4 Constant current control part 5 LED
6 Power failure detection unit 11 Wall switch 31 Backup power supply 63 Transistor

Claims (2)

  An LED lighting device that turns on an LED with power from an external commercial power source, and the commercial power is input regardless of whether the on / off switch provided between the commercial power source is turned on or off. A power supply unit that outputs DC power of a primary voltage and charges a backup power source, a constant current control unit that boosts the DC power of the primary voltage to light an LED, and a primary voltage output from the power supply unit. And a power failure detection unit that turns on the switching element when DC power is lost and supplies the DC power charged in the backup power source to the constant current control unit to keep the LED on. LED lighting device.   The LED lighting device according to claim 1, wherein the backup power source is an electric double layer capacitor.

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