JP6087981B2 - Lighting device - Google Patents

Description

  The present invention relates to a lighting device. The present invention particularly relates to an LED lighting device.

  By turning off the lights, the room becomes completely dark and the safety of the user cannot be ensured. Therefore, there is a delayed turn-off technique in which a lighting device that can be operated with a remote control is turned on for a predetermined time only when turned off with the remote control. On the other hand, when the lighting device is turned off by a wall switch or when a power failure occurs, the lighting device suddenly becomes dark and there is a risk that the safety of the user is not ensured and a dangerous state is brought about.

  For this reason, there is a technique for continuing lighting of the lighting device for a certain time even when the power is shut off (see, for example, Patent Document 1).

JP 2009-245638 A JP 2010-056314 A JP 2009-205850 A JP 2008-126958 A International Publication No. 2011/024102

  In Patent Literature 1, an auxiliary power supply unit is used, and the lighting device is configured to charge the auxiliary power supply unit separately from the LED as a load while commercial power is supplied.

  For this reason, there has been a problem that, for a certain period (until the capacitor of the auxiliary power supply unit is charged), it is necessary to supply power to the auxiliary power supply unit in addition to supplying power to the LED as a load. In addition, the auxiliary power supply section gradually consumes the stored power by variable resistance or PWM (pulse width modulation) control so that the LED is delayed and extinguished after the external power supply (AC (alternating current) power supply, etc.) stops. However, there is a problem that a dedicated circuit for that purpose becomes large and the lighting device becomes expensive.

  An object of the present invention is to light an LED for a certain period of time using an existing capacitor after an external power source is turned off, for example.

A lighting device according to one embodiment of the present invention includes:
An LED that emits light;
A circuit for rectifying and smoothing an input voltage from an external power source that is an AC power source;
The power supply unit having a capacitor connected in parallel with the LED, and when the power is supplied from the external power supply to the circuit, the capacitor is charged by the input voltage from the external power supply rectified and smoothed by the circuit, When power supply from the external power supply to the circuit is stopped, a power supply unit that outputs the current charged in the capacitor to the LED;
A power supply monitoring unit that is connected to a connection portion between the external power supply and the circuit and monitors a power supply state from the external power supply to the circuit;
And a control unit that controls the current output from the power supply unit to flow to the LED when the power supply monitoring unit detects that the power supply from the external power supply to the circuit is stopped.

  According to one aspect of the present invention, an LED can be lit for a certain period of time using an existing capacitor after the external power supply is turned off.

FIG. 3 is a circuit diagram illustrating a configuration of the LED lighting device according to the first embodiment. FIG. 6 is a circuit diagram showing a configuration of an LED lighting device according to Embodiment 2.

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

Embodiment 1 FIG.
FIG. 1 is a circuit diagram showing a configuration of an LED lighting device 10 (an example of a lighting device) according to the present embodiment.

  In FIG. 1, the LED lighting device 10 includes an LED module 35 on which a plurality of LEDs that emit light are mounted, and an LED lighting device 11 to which the LED module 35 is connected.

  The LED lighting device 11 includes an AC power supply detection circuit 14 (an example of a power supply monitoring unit) that detects an on / off state of an AC power supply 17 (an example of an external power supply), and a power factor improvement circuit that improves the power factor of an input current. 12, a lighting circuit 13 (an example of a power supply unit) that outputs a constant current or a constant voltage to the LED module 35 to light the LED, a control circuit 22 that controls the power factor correction circuit 12, and a lighting circuit 13. And a delay control device 36 (an example of a control unit).

  The AC power supply detection circuit 14 monitors the state of power supply from the AC power supply 17. When the AC power supply detection circuit 14 detects that the power supply from the AC power supply 17 is stopped, the AC power supply detection circuit 14 sends a signal indicating that the power supply from the AC power supply 17 is stopped (the AC power supply 17 is off) to the delay control device 36. Output.

  The power factor correction circuit 12 includes a diode bridge 18 that generates a pulsating voltage by full-wave rectifying the input voltage from the AC power supply 17, a capacitor 19 that smoothes the pulsating voltage, and an inductor that boosts the voltage of the capacitor 19. 20 and MOSFET 21, a diode 24 connected to the inductor 20 and MOSFET 21, an electrolytic capacitor 27 connected to the diode 24, and series-connected resistors 25 and 26 connected in parallel to the electrolytic capacitor 27. And a feedback unit 23 that is connected to the midpoint of the resistors 25 and 26 and outputs a feedback signal to the control circuit 22.

  The MOSFET 21 is controlled by the control circuit 22 to perform an on / off switching operation. When MOSFET 21 is on, a current flows through inductor 20 to store energy. When the MOSFET 21 is turned off, the energy stored in the inductor 20 is released to the electrolytic capacitor 27 through the diode 24, and the voltage of the electrolytic capacitor 27 is boosted to a voltage higher than that of the capacitor 19. The voltage generated in the electrolytic capacitor 27 is divided by the resistor 25 and the resistor 26 and input to the control circuit 22 through the feedback unit 23. Based on this voltage, the control circuit 22 controls the on / off of the MOSFET 21 so that the voltage of the electrolytic capacitor 27 becomes constant (about 400 V).

  The lighting circuit 13 includes a MOSFET 28 connected in parallel to the electrolytic capacitor 27, a diode 31 connected in series to the MOSFET 28, an inductor 32 connected in parallel to the diode 31, and a series connection to the inductor 32. An electrolytic capacitor 33 (an example of a capacitor), a resistor 34 connected in series to the electrolytic capacitor 33, a feedback unit 30 connected to the middle point of the resistor 34 and the electrolytic capacitor 33, and outputting a feedback signal to the control circuit 29 Is provided.

  The MOSFET 28 is on / off controlled by a control circuit 29. When the MOSFET 28 is turned on, a current flows through the path of the inductor 32, the electrolytic capacitor 33, and the resistor 34, and the electrolytic capacitor 33 is charged. At this time, energy is stored in the inductor 32. When MOSFET 28 is turned off, the energy stored in inductor 32 is released, current flows in the order of electrolytic capacitor 33, resistor 34, and diode 31, and electrolytic capacitor 33 is charged. When the voltage of the charged electrolytic capacitor 33 exceeds the forward voltage of the LED module 35, a current flows through the LED module 35. When a current flows through the resistor 34, a voltage is generated at the resistor 34 and is input to the control circuit 29 via the feedback unit 30. Based on this voltage, the control circuit 29 performs on / off control of the MOSFET 28 so that the current flowing through the LED becomes constant.

  As described above, the lighting circuit 13 includes the electrolytic capacitor 33 connected in parallel with the plurality of LEDs mounted on the LED module 35. When the lighting circuit 13 is supplied with power from the AC power supply 17 (when the AC power supply 17 is turned on), the lighting circuit 13 charges the electrolytic capacitor 33 and a plurality of LEDs mounted on the LED module 35 with a current smoothed by the electrolytic capacitor 33. Output to. When the power supply from the AC power supply 17 is stopped (when the AC power supply 17 is turned off), the lighting circuit 13 outputs the current charged in the electrolytic capacitor 33 to the plurality of LEDs mounted on the LED module 35. The output of current to the LED module 35 is stopped.

  The LED module 35 includes five LEDs connected in series, and is connected to the electrolytic capacitor 33 in parallel.

  The delay control device 36 is connected to the transistor 37 connected in parallel to the three LEDs on the low potential side among the five LEDs connected in series, and to the AC power supply detection circuit 14, and the transistor 37 is turned on. And a control circuit 38 for controlling OFF.

  When the control circuit 38 is notified by the AC power supply detection circuit 14 that the AC power supply 17 has been cut off, the control circuit 38 controls the transistor 37 to be turned on, and a part of the LEDs of the LED module 35 (in this embodiment, in series). Among the five connected LEDs, three LEDs on the low potential side are short-circuited.

  As described above, when the signal indicating that the power supply from the AC power supply 17 is stopped by the AC power supply detection circuit 14 is input to the delay control device 36, the current output from the lighting circuit 13 is supplied to the LED module 35. It controls so that it may flow into some LED (2 LED) among some mounted LED (5 LED). As a result, some of the LEDs (two LEDs) are turned on for a while after the AC power supply 17 is shut off and then turned off. That is, some of the LEDs (two LEDs) are turned off with delay. On the other hand, LEDs (three LEDs) other than the some LEDs (an example of at least two LEDs) are turned off immediately after the AC power supply 17 is shut off. That is, the LEDs other than the part of the LEDs (three LEDs) are immediately turned off.

  Specifically, when a signal indicating that power supply from the AC power supply 17 is stopped by the AC power supply detection circuit 14 is input to the delay control device 36, two or more LEDs (5 pieces connected in series) are connected. Among the LEDs), the LEDs that are immediately turned off (three LEDs) are short-circuited. For this purpose, in the present embodiment, the delay control device 36 includes a transistor 37 connected in parallel with the LEDs that are immediately turned off (three LEDs). When a signal indicating that the power supply from the AC power supply 17 is stopped is input from the AC power supply detection circuit 14, the delay control device 36 operates the transistor 37 in the active region for a certain period of time and then turns on the transistor 37. As a result, the LEDs that are immediately turned off (three LEDs) can be turned off after gradually darkening.

  As the plurality of LEDs (five LEDs) mounted on the LED module 35, those that emit light having the same color temperature may be used, but those that emit light having different color temperatures may be used. For example, an LED that emits light having a color temperature lower than that of an LED that is immediately turned off (three LEDs) may be used as the LED that is turned off late (two LEDs). In this case, even when the power is shut off, the room where the LED lighting device 10 is installed can be kept brighter than when all LEDs emit light having the same color temperature. Therefore, the safety of the user can be ensured more reliably.

  In the present embodiment, the LED module 35 is composed of five LEDs connected in series. However, the LED module 35 is connected in series with 4 or less (but 2 or more) or 6 or more. You may be comprised with LED. Moreover, in this Embodiment, when AC power supply 17 is interrupted | blocked, 3 LEDs are short-circuited among 5 LEDs, However, 2 or less or 4 LEDs may be short-circuited.

  Next, operation | movement of the LED lighting apparatus 10 in this Embodiment is demonstrated.

  When the AC power supply 17 is turned off, the AC power supply detection circuit 14 detects the off state of the AC power supply 17 and outputs a signal to the delay control device 36. The control circuit 38 in the delay control device 36 reads the signal from the AC power supply detection circuit 14 and outputs the signal to the transistor 37. The transistor 37 is actively turned on from off (open) and gradually turned on (that is, operates as a variable resistor). That is, the control circuit 38 controls the transistor 37 in the active region.

  In the present embodiment, among the five LEDs mounted on the LED module 35, the three LEDs on the low potential side are short-circuited by the transistor 37 almost simultaneously with the interruption of the AC power supply 17, and the remaining two LEDs Only lights up.

  Since the load on the electrolytic capacitor 33 becomes 2/5, consumption of the charging energy of the electrolytic capacitor 33 is suppressed, and the two LEDs continue to be lit for a certain period of time after the AC power supply 17 is shut off (that is, delayed extinction). To do).

  As described above, in this embodiment, when detecting that the AC power supply 17 is turned off, the number of LEDs to be turned on is reduced (for example, to 1/2 or 1/3), so that the special power supply or power supply side is reduced. Even without this control, the LED can be lit for a predetermined time. In other words, according to the present embodiment, as a device for reducing the power consumption of the LED as a load when the AC power supply 17 is shut off, the number of LEDs is limited so that the electrolytic capacitor 33 included in the existing power supply can be used for a predetermined time. The LED can be turned on. Further, since the electric charge of the electrolytic capacitor 33 can be used up when the AC power supply 17 is shut off, there is no possibility of subsequent electric shock and the safety is improved.

  As described above, in the present embodiment, the LED lighting device 10 includes the LED lighting device 11 that turns on the plurality of LEDs, the electrolytic capacitor 33 that is connected in parallel with the plurality of LEDs and rectifies the pulsating current, and the AC. An AC power source detection circuit 14 that detects the power source 17 and a delay control device 36 that causes the LED to emit light for a predetermined period when the AC power source 17 supplied to the LED lighting device 11 is cut off are provided. For this reason, according to the present embodiment, it is possible to turn on some of the plurality of LEDs for a certain period of time using the existing electrolytic capacitor 33 after the AC power supply 17 is turned off.

Embodiment 2. FIG.
In the present embodiment, differences from the first embodiment will be mainly described.

  FIG. 2 is a circuit diagram showing a configuration of the LED lighting device 10 according to the present embodiment.

  In FIG. 2, the LED module 35 includes three LED groups 35a to 35c connected in parallel. Each LED group is composed of five LEDs (an example of two or more LEDs) connected in series.

  The delay control device 36 includes transistors 40 and 41 connected between the cathodes of the two LED groups 35a and 35b and the GND (ground) among the three LED groups 35a to 35c of the LED module 35, respectively. . A compensation diode 39 is connected to the LED group 35c to which the transistors 40 and 41 are not connected.

  Other basic circuit configurations are the same as those in the first embodiment.

  When a signal indicating that the power supply from the AC power supply 17 is stopped by the AC power supply detection circuit 14 is input to the delay control device 36, the current output from the lighting circuit 13 is supplied to the plurality of LEDs mounted on the LED module 35. It controls so that it may flow into LED groups (one LED group 35c) other than some LED groups (two LED groups 35a and 35b) among LED groups (three LED groups 35a-35c). As a result, the partial LED groups (two LED groups 35a and 35b) (an example of at least two LED groups) are turned off immediately after the AC power supply 17 is shut off. That is, the partial LED group (two LED groups 35a and 35b) is immediately turned off. On the other hand, the LED groups (one LED group 35c) other than the part of the LED groups are turned on for a while after the AC power supply 17 is shut off and then turned off. That is, LED groups other than the part of the LED groups (one LED group 35c) are turned off with delay.

  Specifically, when a signal indicating that the power supply from the AC power supply 17 is stopped is input by the AC power supply detection circuit 14, the delay control device 36 includes a plurality of LED groups (three LEDs) mounted on the LED module 35. LED groups (two LED groups 35a and 35b) that are immediately turned off among the LED groups 35a to 35c) are opened. Therefore, in the present embodiment, the delay control device 36 includes transistors 40 and 41 connected in series with an LED group (two LED groups 35a and 35b) to be immediately turned off. When a signal indicating that the power supply from the AC power supply 17 is stopped is input by the AC power supply detection circuit 14, the delay control device 36 operates the transistors 40 and 41 in the active region for a certain period of time and then turns the transistors 40 and 41 on. Turn off. Thereby, the LED group (two LED groups 35a and 35b) to be immediately turned off can be turned off after gradually darkening.

  When the signal indicating that the power supply from the AC power supply 17 is stopped is input by the AC power supply detection circuit 14, the delay control device 36 opens all the LED groups (two LED groups 35 a and 35 b) that are immediately turned off simultaneously. However, it may be opened at different timings. For example, the delay control device 36 may open the LED groups (two LED groups 35a and 35b) that are immediately turned off in a predetermined order. In this case, the LED groups to be immediately turned off (two LED groups 35a and 35b) can be turned off one by one in order. At this time, the LED groups may be turned off one by one in order according to the discharge speed of the electrolytic capacitor 33. That is, each time the forward voltage of one LED group is discharged from the electrolytic capacitor 33, the delay control device 36 is connected to one of the LED groups (one of the LED groups 35a and 35b) (transistor 40, 41) may be controlled to be turned off to open the one LED group. At this time, for example, an elapsed time from when a signal indicating that power supply from the AC power supply 17 is stopped by the AC power supply detection circuit 14 is input to the microcomputer or the like (control circuit 38) built in the delay control device 36. Measure. Then, the transistor is turned off when the discharge time of the electrolytic capacitor 33 previously stored in the memory or the like (the time during which the forward voltage of one LED group is discharged) has elapsed. The discharge time of the electrolytic capacitor 33 may be different for each LED group. In this case, the discharge time for each LED group is stored in a memory or the like.

  As a plurality of LED groups (three LED groups 35a to 35c) mounted on the LED module 35, those that emit light having the same color temperature may be used, but those that emit light having different color temperatures may be used. May be. For example, an LED group that emits light with a delayed color temperature (one LED group 35c) that emits light whose color temperature is lower than that of the LED group that is immediately extinguished (two LED groups 35a and 35b) may be used. In this case, even when the power is shut off, the room in which the LED lighting device 10 is installed can be kept brighter than the case where all the LED groups emit light having the same color temperature. Therefore, the safety of the user can be ensured more reliably.

  In this embodiment, the LED module 35 includes three LED groups 35a to 35c connected in parallel. The LED module 35 includes two or four or more LED groups connected in parallel. It may be configured. In the present embodiment, when the AC power supply 17 is cut off, the two LED groups 35a and 35b are opened out of the three LED groups 35a to 35c, but only one LED group is opened. You may let them.

  Next, operation | movement of the LED lighting apparatus 10 in this Embodiment is demonstrated.

  When the AC power supply 17 is turned off, the AC power supply detection circuit 14 detects the off state of the AC power supply 17 and outputs a signal to the delay control device 36. The control circuit 38 in the delay control device 36 reads the signal from the AC power supply detection circuit 14 and outputs the signal to the transistors 40 and 41. The transistors 40 and 41 are actively turned on (shorted) and gradually turned off (that is, operate as variable resistors). That is, the control circuit 38 controls the transistors 40 and 41 in the active region.

  In the present embodiment, of the three LED groups 35 a to 35 c mounted on the LED module 35, two LED groups 35 a and 35 b are separated by the transistors 40 and 41 almost simultaneously with the interruption of the AC power supply 17. The LED group 35c connected to the compensation diode 39 is turned off with a delay.

  As mentioned above, although embodiment of this invention was described, you may implement combining 2 or more embodiment among these. Alternatively, one of these embodiments may be partially implemented. Or you may implement combining two or more embodiment among these partially.

  DESCRIPTION OF SYMBOLS 10 LED lighting device, 11 LED lighting device, 12 Power factor improvement circuit, 13 Lighting circuit, 14 AC power supply detection circuit, 17 AC power supply, 18 Diode bridge, 19 Capacitor, 20, 32 Inductor, 21,28 MOSFET, 22, 29 , 38 control circuit, 23, 30 feedback unit, 24, 31 diode, 25, 26, 34 resistance, 27, 33 electrolytic capacitor, 35 LED module, 35a, 35b, 35c LED group, 36 delay control device, 37, 40, 41 Transistor, 39 Compensation diode.

Claims (5)

An LED that emits light;
A circuit for rectifying and smoothing an input voltage from an external power source that is an AC power source;
A power supply unit having a capacitor Ru Tei is connected in parallel with the LED, charge the capacitor by the case where the external power source is supplying power to the circuit, the input voltage from the external power source which is rectified and smoothed by the circuit And outputting the current smoothed by the capacitor to the LED, and when the power supply from the external power supply to the circuit is stopped, the power supply unit that outputs the current charged in the capacitor to the LED;
A power supply monitoring unit that is connected to a connection portion between the external power supply and the circuit and monitors a power supply state from the external power supply to the circuit;
A control unit that controls to turn off the LED that is turned on by the current output from the power supply unit when the power supply monitoring unit detects that the power supply from the external power supply to the circuit is stopped; A lighting device comprising: The LEDs are a plurality of LED groups connected in parallel, and each LED group is a plurality of LED groups composed of two or more LEDs connected in series,
2. The lighting device according to claim 1, wherein when the power supply monitoring unit detects that power supply from the external power supply is stopped, the control unit opens a part of the plurality of LED groups. .   The control unit includes a transistor connected in series with the partial LED group, and when the power supply monitoring unit detects that power supply from the external power supply is stopped, the transistor is fixed in an active region. The lighting device according to claim 2, wherein the transistor is turned off after operating for a period of time. The some LED groups are at least two LED groups;
4. The lighting device according to claim 2, wherein when the power supply monitoring unit detects that power supply from the external power supply is stopped, the control unit opens the at least two LED groups in a predetermined order. 5. .   5. The lighting device according to claim 2, wherein the partial LED group emits light having a higher color temperature than an LED group other than the partial LED group.

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