JP5725736B2 - LED power supply device and LED lighting apparatus - Google Patents

Description

  The present invention relates to an LED power supply device and an LED lighting fixture.

There is a need for highly efficient LED lighting to reduce CO ₂ . Furthermore, there is a demand for LED illumination that can change the light color according to the usage environment.

  In conventional LED lighting, a plurality of LED groups having different light colors are mounted on a single lighting fixture, and a constant current circuit individually connected to each LED group is controlled one by one to increase the brightness for each LED group. By changing it, the light color was made variable (for example, refer to Patent Document 1).

JP 2009-302008 A

  Conventional LED lighting fixtures are expensive because a constant current circuit is individually connected to each LED group, and there is a problem that the loss of the constant current circuit increases when the LED current increases.

  An object of the present invention is, for example, to obtain highly efficient light color variable LED illumination at low cost.

An LED power supply apparatus according to one aspect of the present invention is provided.
A constant current power supply circuit for supplying a constant current;
Each of a plurality of light emitting units each including at least one LED and emitting light by turning on the at least one LED with a constant current from the constant current power supply circuit, wherein any of the plurality of light emitting units connected in parallel with each other At least one switch element connected in series, turned on to be conductive, and turned off to be cut off,
And a control circuit that causes the light emitting unit connected to the at least one switch element to blink at the period by switching on / off of the at least one switch element at a predetermined period.

  According to one aspect of the present invention, the LED power supply device does not need to be provided with a constant current power supply circuit for each light emitting unit, so that highly efficient light color variable LED illumination can be obtained at low cost.

1 is a circuit diagram of a lighting device according to Embodiment 1. FIG. It is a figure which shows the external appearance of the surface of the LED module with which the illuminating device which concerns on Embodiment 1 is provided, and the connection between an LED module and a color temperature control circuit. (A) The figure which shows the example of the waveform of a PWM signal, (b) The graph which shows the relationship between the duty ratio of a light control signal, and brightness, (c) The graph which shows the relationship between the duty ratio of a color temperature signal, and color temperature. . 3 is a timing chart illustrating an operation example of the lighting apparatus according to Embodiment 1. (A) A graph showing the relationship between the duty ratio of the FET and the brightness and color temperature, and (b) a graph showing the relationship between the duty ratio of the dimming signal and the brightness and color temperature. FIG. 6 is a circuit diagram of a lighting apparatus according to Embodiment 2. FIG. 6 is a circuit diagram of a lighting device according to Embodiment 3. FIG. 6 is a circuit diagram of a lighting device according to Embodiment 4. 10 is a timing chart illustrating an operation example of the lighting apparatus according to the fourth embodiment. FIG. 10 is a circuit diagram of a lighting device according to Embodiment 5. 10 is a timing chart illustrating an operation example of the lighting apparatus according to Embodiment 5.

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

Embodiment 1 FIG.
FIG. 1 is a circuit diagram of a lighting device 10 (LED lighting fixture) according to the present embodiment. FIG. 2 is a diagram illustrating the appearance of the surface of the LED module 11 included in the lighting device 10 and the connection between the LED module 11 and the color temperature control circuit 50.

  The lighting device 10 includes a power supply device 20 (LED power supply device) to which a commercial AC power supply AC is supplied, and an LED module 11 that is lit by inputting a direct current output from the power supply device 20.

  The LED module 11 includes, as a plurality of light emitting units, an LED array 1a (also referred to as “LED1”) (first light emitting unit) and an LED array 2a (also referred to as “LED2”) (second light emitting unit). The LED module 11 includes a substrate 12 (for example, a printed circuit board) on which the LED array 1a and the LED array 2a are mounted. Each of the LED array 1a and the LED array 2a includes at least one LED, and emits light by turning on the at least one LED by a constant current from an output constant current circuit 40 (constant current power supply circuit) described later. Specifically, the LED array 1a includes a plurality of first light color LEDs having a color temperature of, for example, 3000K (Kelvin), and emits light having a color temperature of 3000K (first color light) as a whole. The LED array 2a includes a plurality of second light color LEDs having a color temperature of, for example, 5000K, and emits light having a color temperature of 5000K as a whole (second color light different from the first color). The LED array 1a and the LED array 2a are connected in parallel to each other, and the first light color LED and the second light color LED constituting the LED array 1a and the LED array 2a are mounted on the substrate 12 so as to be alternately arranged. The Thus, by alternately arranging the first light color LEDs constituting the LED array 1a and the second light color LEDs constituting the LED array 2a, the emission color of the first light color LED and the second light color LED are changed. It becomes easy to mix with luminescent color.

  The power supply device 20 includes a rectifying / smoothing circuit 30, an output constant current circuit 40, a color temperature control circuit 50, and a control circuit 60 (for example, a microcomputer). The rectifying / smoothing circuit 30 performs full-wave rectification on the commercial AC power supply AC by the diode bridge 31 and smoothes it by the smoothing capacitor 32 to obtain a DC voltage. The output constant current circuit 40 supplies a constant current. Specifically, the output constant current circuit 40 receives the DC voltage of the rectifying / smoothing circuit 30 and outputs a constant DC current. The color temperature control circuit 50 receives the direct current output from the output constant current circuit 40 and controls the current flowing through the connected LED module 11. The control circuit 60 receives a dimming signal and a color temperature signal from the outside (such as a dimmer) and outputs an output control signal for controlling the output constant current circuit 40 based on the input dimming signal and color temperature signal. And a color temperature control signal for controlling the color temperature control circuit 50 is generated.

  The dimming signal input to the power supply device 20 (control circuit 60) is a signal indicating brightness information according to a PWM (pulse width modulation) duty ratio (a dimming signal for instructing the dimming degree of the plurality of light emitting units as a whole). It is. The color temperature signal input to the power supply device 20 (control circuit 60) is a signal indicating the color temperature information based on the PWM duty ratio (a toning signal for instructing the emission color of the entire plurality of light emitting units).

  The output constant current circuit 40 includes a constant current control FET 41, a resistor 42, a choke coil 43, a transistor 44, a diode 45, a current detection resistor 46, a constant current control circuit 47, and an electrolytic capacitor 48. The drain terminal of the constant current control FET 41 is connected to the high potential side of the rectifying and smoothing circuit 30. The resistor 42 is connected in parallel to the drain terminal and the gate terminal of the FET 41. One end of the choke coil 43 is connected to the source terminal of the FET 41. The transistor 44 has a collector terminal connected to the gate terminal of the FET 41 and an emitter terminal connected to the low potential side of the rectifying and smoothing circuit 30. The diode 45 has a cathode terminal connected to the source terminal of the FET and an anode terminal connected to the low potential side of the rectifying and smoothing circuit 30. One end of the current detection resistor 46 is connected to the low potential side of the rectifying and smoothing circuit 30, and the other end is connected to the color temperature control circuit 50 in the subsequent stage. The constant current control circuit 47 is connected to the other end of the current detection resistor 46, the base terminal of the transistor 44, and the control circuit 60. The electrolytic capacitor 48 has a positive electrode connected to the source terminal of the FET 41 via the choke coil 43 and a negative electrode connected to the low potential side of the rectifying and smoothing circuit 30. The output constant current circuit 40 in FIG. 1 is an example in which the FET 41 and the choke coil 43 are arranged on the high potential (High) side, but the FET 41 and the choke coil 43 may be arranged on the low potential (Low) side. .

  The control circuit 60 generates an output control signal for controlling the current output from the output constant current circuit 40 according to the duty ratio of the dimming signal input from the outside. The constant current control circuit 47 of the output constant current circuit 40 receives the output control signal from the control circuit 60, controls the switching of the transistor 44 based on the input output control signal, and the FET 41 is switched by the switching of the transistor 44. Is turned on / off to obtain a predetermined constant current. In accordance with this current, the brightness of light emitted from the entire LED module 11 changes.

  Only a direct current flows through the wiring between the output constant current circuit 40 and the substrate 12 of the LED module 11.

  The color temperature control circuit 50 includes, as a plurality of switch elements, FET1 (first switch element) that is a switch element connected in series with the LED array 1a and FET2 (second switch) that is a switch element connected in series with the LED array 2a. Switch element). The color temperature control circuit 50 also includes an FET drive circuit 51 that controls ON / OFF of the FET1 and FET2. Each of FET1 and FET2 is turned on to be in a conductive state, and turned off to be in a cut-off state. Therefore, the LED array 1a can be turned on when the FET 1 is turned on, and the LED array 2a can be turned on when the FET 2 is turned on.

  The control circuit 60 controls the FET drive circuit 51 to switch on / off of the FET 1 at a predetermined cycle, thereby causing the LED array 1a connected to the FET 1 to blink at that cycle. Further, the FET drive circuit 51 controls the FET drive circuit 51 to switch on / off of the FET 2 at a predetermined cycle, thereby causing the LED array 2a connected to the FET 2 to blink at that cycle. Specifically, the control circuit 60 outputs a color temperature control signal for controlling the cycle in which the color temperature control circuit 50 turns on and off the FET 1 and FET 2 in accordance with the duty ratio of the color temperature signal input from the outside. Generate. The FET drive circuit 51 of the color temperature control circuit 50 receives the color temperature control signal from the control circuit 60 and controls on / off of the FET 1 and FET 2 based on the input color temperature control signal. The color temperature of the light emitted from the entire LED module 11 changes according to the on / off cycle.

  Next, the operation of the lighting device 10 (lighting control method) will be described.

  FIG. 3A is a diagram illustrating an example of a waveform of a PWM signal. FIG. 3B is a graph showing the relationship between the duty ratio of the dimming signal and the brightness, and FIG. 3C is a graph showing the relationship between the duty ratio of the color temperature signal and the color temperature.

  As shown in FIG. 3A, the duty ratio (Duty) is determined from the rising edge of the PWM signal to the falling edge with respect to the time T (time of one cycle) from the rising edge of the PWM signal to the next rising edge. It is the ratio of time t. As described above, the dimming signal and the color temperature signal input from the outside are both PWM signals, and the operation (the dimming control process and the color temperature control process) is performed with the duty ratio (that is, the ratio of the on time). This is a signal for instructing the control circuit 60.

  As shown in FIG. 3B, if the duty ratio of the input dimming signal is 0%, the control circuit 60 adjusts the brightness (dimming degree) of the light source to 100% and the input dimming signal. If the duty ratio of the optical signal is 100%, the brightness of the light source is adjusted to 0% (turned off). The control circuit 60 darkens the brightness of the light emitted from the LED array 1a and the LED array 2a when the ON time of the dimming signal becomes longer. That is, the control circuit 60 performs control so that the light source is lit darker as the duty ratio of the input dimming signal is larger.

  As shown in FIG. 3C, if the duty ratio of the input color temperature signal is 0%, the control circuit 60 adjusts the color temperature of the light source to 5000K, and the duty ratio of the input color temperature signal. Is 100%, the color temperature of the light source is adjusted to 3000K. When the ON time of the color temperature signal becomes longer, the control circuit 60 lengthens the time that the LED array 1a that emits light having a color temperature of 3000K is turned on and the time that the LED array 2a that emits light having a color temperature of 5000K is turned on. shorten. Therefore, when the ON time of the color temperature signal becomes longer, the color temperature of the light emitted from the LED array 1a and the LED array 2a is relatively close to 3000K, which is the color temperature emitted by the LED array 1a. That is, the control circuit 60 performs control so that the color temperature of the light source decreases as the duty ratio of the input color temperature signal increases.

  FIGS. 4A to 4C are timing charts showing an operation example of the illumination device 10. FIG. 5A is a graph showing the relationship between the duty ratio, brightness, and color temperature of FET1 and FET2, and FIG. 5B shows the relationship between the duty ratio of the dimming signal, brightness, and color temperature. It is a graph.

  As described above, the power supply device 20 of the lighting device 10 has a dimming signal for inputting brightness information as a signal by a PWM duty ratio and a color temperature signal for inputting color temperature information by a PWM duty ratio. Applied. These two signals are received by the control circuit 60.

  The control circuit 60 controls the switching of the constant current control FET 41 of the output constant current circuit 40 based on the dimming signal, and the output current is controlled by the DC / DC converter including the choke coil 43, the electrolytic capacitor 48, and the diode 45. Adjust the brightness by controlling the value of. At this time, the control circuit 60 inputs to the output constant current circuit 40 an output control signal that indicates a constant current value for obtaining the dimming degree indicated by the duty ratio of the dimming signal. Note that the control circuit 60 may input the dimming signal as it is to the output constant current circuit 40 as an output control signal. The output constant current circuit 40 detects the output current, that is, the current flowing through the LED by the current detection resistor 46, and supplies the constant current according to the current value indicated by the output control signal to the LED by the constant current control circuit 47. .

  The control circuit 60 controls the switching of the FET1 and FET2 of the color temperature control circuit 50 based on the color temperature signal, and drives the LED array 1a to emit light while the FET1 is on, and the LED2 when the FET2 is on. The array 2a is driven to emit light. At this time, the control circuit 60 inputs to the color temperature control circuit 50 a color temperature control signal instructing a switching operation for obtaining a color temperature indicated by the duty ratio of the color temperature signal. The control circuit 60 may input the color temperature signal as it is to the color temperature control circuit 50 as the color temperature control signal. The color temperature control circuit 50 performs a switching operation instructed by the color temperature control signal by the FET drive circuit 51.

  As described above, for example, if the LED array 1a has an emission color of 3000K and the LED array 2a has an emission color of 5000K, the output constant current circuit 40 is the same as the LED array 1a and the LED array 2a while the FET1 and FET2 are on. Apply current. For example, if the ON period of FET1 and FET2 is 50% respectively (FET1 is turned on and FET2 is turned off in 50% of one cycle, and FET1 is turned off and FET2 is turned on in the remaining 50% of one cycle) The combined emission color of the LED array 1a and the LED array 2a can be 4500K. By changing the ratio of the ON period of FET1 and FET2, the composite color can be varied from 3000K to 5000K. That is, a light color between 3000K and 5000K can be freely created by controlling the FET1 and FET2 on / off at a predetermined cycle. At this time, if the combined luminous fluxes emitted from the LED array 1a and the LED array 2a emit light having substantially the same luminous flux when the LED array 1a and the LED array 2a are supplied with the same current, respectively, FIG. As shown in FIG. If the LED array 1a and the LED array 2a emit light of different luminous fluxes even when the same current is supplied, the output current of the output constant current circuit 40 is the luminous flux ratio of the LED array 1a and the LED array 2a (the same The brightness can be controlled to be constant by adjusting it according to the ratio of the luminous flux when the current is passed.

  Further, when it is desired to change only the combined brightness with a constant light color, as shown in FIG. 5B, the output of the output constant current circuit 40 is maintained while the FET1 and FET2 on / off control states are kept constant. It can be realized by changing. It is desirable that the on / off period of the FET1 and FET2 is equal to or higher than a frequency (generally 200 Hz or higher) that human eyes cannot recognize as flicker.

  Hereinafter, examples of FIGS. 4A to 4C will be described in detail. Here, the first light color LED (color temperature is 3000K) constituting the LED array 1a and the second light color LED (color temperature is 5000K) constituting the LED array 2a are both currents of 0.4A as an example. Is input at 100% light output, and the light output is proportional to the current value. In addition, the characteristic of 1st light color LED and 2nd light color LED is not restricted to this.

  In the example of FIG. 4A, the control circuit 60 of the power supply device 20 controls the output constant current circuit 40 to set its output current to 0.4A. Further, the control circuit 60 controls the color temperature control circuit 50 to turn on the FET 1 by 25% for one cycle and turn on the FET 2 by 75% for one cycle. At this time, the control circuit 60 controls the FET 1 and the FET 2 to be alternately turned on (so that on / off is inverted). Since FET1 is on for 25% of one cycle, the LED array 1a (LED1) is turned on with only 100% (100% of the entire lighting device 10) of light output for 25% of one cycle, and 75% of one cycle is turned off. To do. On the other hand, since the FET2 is 75% on for one cycle, the LED array 2a (LED2) is turned on with only 75% of the light output of 100% (100% of the entire illumination device 10), and 25% of the one cycle. Turns off. Thereby, the (appearance) brightness of the light emitted from the illumination device 100 is 100%, and the (appearance) color temperature is 4500K (= 3000 × 0.25 + 5000 × 0.75). In this example, it is assumed that a PWM signal having a duty ratio of 0% (a signal for instructing a dimming degree of 100%) is input to the control circuit 60 as a dimming signal. Further, it is assumed that a PWM signal having a duty ratio of 43.75% (a signal for instructing a color temperature of 4500K) is input to the control circuit 60 as the color temperature signal.

  In the example of FIG. 4B, the control circuit 60 of the power supply device 20 controls the output constant current circuit 40 to set its output current to 0.4A. Further, the control circuit 60 controls the color temperature control circuit 50 to turn on the FET 1 by 50% for one cycle and turn on the FET 2 by 50% for one cycle. At this time, the control circuit 60 controls the FET 1 and the FET 2 to be alternately turned on (so that on / off is inverted). Since the FET 1 is ON for 50% in one cycle, the LED array 1a (LED1) is turned on with only 100% light output for 50% in one cycle, and is turned off for 50% in one cycle. Similarly, since the FET 2 is ON for 50% in one cycle, the LED array 2a (LED2) is turned on with light output of 100% (100% of the entire lighting device 10) only for 50% in one cycle, and 50 in one cycle. % Goes out. Thereby, the (appearance) brightness of the light emitted from the illumination device 100 is 100%, and the (appearance) color temperature is 4000K (= 3000 × 0.5 + 5000 × 0.5). In this example, it is assumed that a PWM signal having a duty ratio of 0% (a signal for instructing a dimming degree of 100%) is input to the control circuit 60 as a dimming signal. Further, it is assumed that a PWM signal having a duty ratio of 50% (a signal for instructing a color temperature of 4000K) is input to the control circuit 60 as the color temperature signal.

  In the example of FIG. 4C, the control circuit 60 of the power supply device 20 controls the output constant current circuit 40 so that its output current is 0.4A. Further, the control circuit 60 controls the color temperature control circuit 50 to turn on the FET 1 for 75% for one period and turn on the FET 2 for 25% for one period. At this time, the control circuit 60 controls the FET 1 and the FET 2 to be alternately turned on (so that on / off is inverted). Since FET1 is 75% on for one cycle, the LED array 1a (LED1) is turned on with only 100% light output for 75% of one cycle and is turned off for 25% of one cycle. On the other hand, since the FET 2 is on for 25% in one cycle, the LED array 2a (LED2) is lit at a light output of 100% (100% of the entire lighting device 10) for only 25% in one cycle and 75% in one cycle. Turns off. Thereby, the (appearance) brightness of the light emitted from the illumination device 100 is 100%, and the (appearance) color temperature is 3500K (= 3000 × 0.75 + 5000 × 0.25). In this example, it is assumed that a PWM signal having a duty ratio of 0% (a signal for instructing a dimming degree of 100%) is input to the control circuit 60 as a dimming signal. Further, it is assumed that a PWM signal having a duty ratio of 56.25% (a signal for instructing a color temperature of 3500K) is input to the control circuit 60 as the color temperature signal.

  In the example of FIGS. 4A to 4C, the control circuit 60 controls the constant current supplied to the output constant current circuit 40 according to the input dimming signal, whereby the brightness of the light emitted from the lighting device 100 is controlled. Can be easily changed. For example, if a PWM signal having a duty ratio of 50% (a signal for instructing a dimming degree of 50%) is input to the control circuit 60 as the dimming signal, the control circuit 60 supplies a constant current to the output constant current circuit 40. By controlling the current to 50%, the brightness of the light emitted from the lighting device 100 can be halved.

  In the example of FIGS. 4A to 4C, the control circuit 60 controls the FET 1 and FET 2 to be alternately turned on, but either one of the FET 1 and FET 2 is on ( That is, it is only necessary to control so that all the switch elements are not turned off. For example, the FET 1 or the FET 2 may be controlled to be always on.

  As described above, in the present embodiment, the control circuit 60 switches on / off at least one of the plurality of switch elements at a predetermined cycle, thereby causing at least one of the plurality of light emitting units to blink at the cycle. . At this time, the control circuit 60 controls the cycle according to the input color temperature signal.

  As described above, in the present embodiment, since the power supply device 20 has one output constant current circuit 40, not only can the power supply device 20 be configured at low cost, but also a current is passed through the LED array 1a or the LED array 2a. Since the loss of the switch elements (FET1 and FET2) is very small, the efficiency of the entire lighting device 10 can be increased. Furthermore, the entire illumination device 10 can be made inexpensive because of a simple configuration in which the switch element is simply turned on / off.

  The light emission colors of the LED array 1a and the LED array 2a may be other than 3000K and 5000K, respectively. For example, a combination of 4200 to 6500K white or daylight white and 2700 to 3000K light bulb color can be used for practically variable colors. LED lighting can be obtained. Further, the LED array 1a and the LED array 2a do not have to be composed of LEDs of the same light color, and may be selected according to the combined light color (color temperature) when the FET1 and FET2 are turned off. For example, if all four LED arrays 1a are composed of LEDs with a color temperature of 3000K, and the LED array 2a is configured to have two LEDs of 5000K and two LEDs of 3000K, when all the LEDs emit light The color temperature of the obtained luminescent color can be 3500K. In the present embodiment, the LED array 1a and the LED array 2a are each composed of four LEDs, but may be composed of three or less LEDs or five or more LEDs. Alternatively, each of the LED array 1a and the LED array 2a may be replaced with one LED. Further, the LED array 1a and the LED array 2a may be configured by different numbers of LEDs.

  In the present embodiment, the LED module 11 is configured by two light emitting units (LED array 1a, LED array 2a), but the LED module 11 may be configured by three or more light emitting units. In the present embodiment, one switching element (FET1, FET2) is connected in series to each of the two light emitting units (LED array 1a, LED array 2a), but some light emitting units (LED A switch element (FET1 or FET2) may be connected in series only to the array 1a or the LED array 2a). The same applies to the case where there are three or more light emitting units. That is, the power supply device 20 only needs to include at least one switch element.

  In the present embodiment, the LED array 11 is configured by mounting the LED array 1a and the LED array 2a on one substrate 12, but the LED array 1a and the LED array 2a are separately mounted on the two substrates, respectively. The LED module 11 may be configured. In the present embodiment, the first light color LED and the second light color LED constituting the LED array 1a and the LED array 2a are alternately mounted on the substrate 12, but the substrate 12 is not mounted alternately. The first light color LED may be mounted on one side and the second light color LED may be mounted on the other side. Further, in the present embodiment, the first light color LEDs and the second light color LEDs are alternately arranged in a straight line on the substrate 12, but other arrangement methods may be adopted. For example, the first light color LED and the second light color LED may be arranged in a staggered pattern on the substrate 12, may be alternately arranged in a ring shape, or the first light color LED and the first light color LED The two light color LEDs may be arranged randomly so as not to be adjacent to each other. In this way, by preventing two or more LEDs having the same color temperature from being arranged in succession, the color mixing property of the emission color is improved. In the present embodiment, the shape of the substrate 12 constituting the LED module 11 is substantially rectangular. However, the shape of the substrate 12 constituting the LED module 11 may be a square, a circle, a horseshoe shape, or the like. You may form according to the shape of the lighting equipment used.

  In the present embodiment, the LED module 11 and the power supply device 20 may be housed in the same housing or in separate housings. When the LED module 11 and the power supply device 20 are housed in separate housings, only the color temperature control circuit 50 of the power supply device 20 may be housed in the same housing as the LED module 11. At this time, the FET 1 and FET 2 that are switch elements of the color temperature control circuit 50 and the FET drive circuit 51 may be arranged on the same substrate 12 as the LED array 1a and LED array 2a. In this case, when the FET1 and FET2 are turned on / off, the pulsed current flowing through the FET1 and FET2 is only in the substrate 12 of the LED module 11, and the main current between the output constant current circuit 40 and the LED module 11 is Since only a direct current is used, noise generation can be suppressed.

  In the present embodiment, the control circuit 60 of the power supply device 20 performs control so that the light source is lit darker as the duty ratio of the dimming signal is larger. However, the light source is brighter as the duty ratio of the dimming signal is larger. You may control to do. In this embodiment, the control circuit 60 performs control so that the color temperature of the light source decreases as the duty ratio of the color temperature signal increases. However, the color temperature of the light source increases as the duty ratio of the color temperature signal increases. May be controlled to be higher.

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

  FIG. 6 is a circuit diagram of lighting apparatus 10 according to the present embodiment.

  In the present embodiment, a plurality of LED modules 11 similar to those in the first embodiment are connected to the power supply device 20, and the power supply device 20 has one color temperature control circuit 50 corresponding to each LED module 11. It is provided one by one. In this embodiment, the combination of the LED module 11 and the corresponding color temperature control circuit 50 is individually accommodated in the housings 13a and 13b one by one, and at least the output constant current circuit 40 of the power supply device 20 is separated. Is housed in a housing 14.

  For example, the LED module 11 housed in the housing 13a and the LED module 11 housed in the housing 13b are connected in parallel to each other. The color temperature control circuit 50 housed in the housing 13a and the color temperature control circuit 50 housed in the housing 13b are connected to the output constant current circuit 40 and the control circuit 60, respectively. The control circuit 60 outputs the same color temperature signal to the LED module 11 housed in the housing 13a and the LED module 11 housed in the housing 13b, and is housed in the housing 13a from the output constant current circuit 40. A current is supplied to the LED array 1a and LED array 2a of the LED module 11 and the LED array 1a and LED array 2a of the LED module 11 accommodated in the housing 13b. Details of the operations of the power supply device 20 and the LED module 11 are the same as those in the first embodiment, and thus the description thereof is omitted.

  As described above, in the present embodiment, the color temperature control circuit 50 (FET drive circuit 51, FET1, FET2) of the power supply device 20 is provided in the same housing 13 as the LED module 11. That is, the LED module 11 and the color temperature control circuit 50 are disposed in the same housing 13, and the output constant current circuit 40 is disposed in a housing 14 different from the housing 13. For this reason, when the distance between the housing 13 (LED module 11) and the housing 14 (output constant current circuit 40) is increased, the electric wire connecting the housing 13 and the housing 14 extends. The leakage current to the outside can be reduced, or the response deterioration due to the floating capacity caused by the electric wire can be prevented. The LED module 11 and the color temperature control circuit 50 may be arranged on the same board, and the output constant current circuit 40 may be arranged on a board different from this board. A substantially similar effect can be obtained.

Embodiment 3 FIG.
In the present embodiment, differences from the first embodiment will be mainly described.

  FIG. 7 is a circuit diagram of lighting apparatus 10 according to the present embodiment.

  In the present embodiment, FET1 and FET2 which are switching elements of the color temperature control circuit 50 are connected in series to the anode side of the LED array 1a and LED array 2a. That is, in this embodiment, the switch element is connected in series to the high potential side of the LED. The operation is the same as in the first embodiment, but in this embodiment, the cathodes of the LED array 1a and the LED array 2a are always connected to a low potential, and the ground potential is low and stable. It is difficult to suppress the leakage current.

Embodiment 4 FIG.
In the present embodiment, differences from the first embodiment will be mainly described.

  FIG. 8 is a circuit diagram of lighting device 10 (only a part) according to the present embodiment. FIG. 9 is a timing chart illustrating an operation example of the illumination device 10.

  In the present embodiment, three LED arrays similar to those in the first embodiment are connected in parallel, and one switch element is connected in series to each LED array.

  The LED array 1a (first light emitting unit), LED array 2a (second light emitting unit), and LED array 3a (third light emitting unit) connected in parallel are connected to the power supply device 20 (color temperature control circuit 50). . The color temperature control circuit 50 includes three switch elements (FET1, FET2, FET3) connected in series to the LED array 1a, the LED array 2a, and the LED array 3a.

  For example, the LED array 1a and the LED array 2a each include four LEDs having the same color temperature. Here, as in the first embodiment, the LED array 1a is connected in series with LEDs that emit light at a color temperature of 3000K, and the LED array 2a is connected in series with LEDs that emit light at a color temperature of 5000K. Suppose that The LED array 3a includes, for example, two red LEDs.

  The power supply device 20 (color temperature control circuit 50) controls the lighting of the LED array 1a, the LED array 2a, and the LED array 3a by individually turning on / off the FET1, FET2, and FET3, and mixes the respective emission colors. And accurately produce the color of the bulb. For example, the amount of light emitted from the LED array 3a is changed by changing the on-time ratio of the FET 3, and the combined light of the LED array 1a, LED array 2a, and LED array 3a is light within the range of the bulb color on the chromaticity diagram To be.

  For example, as shown in FIG. 9, the control circuit 60 of the power supply device 20 controls the color temperature control circuit 50 to turn on FET 1 by 25% for one cycle, turn FET 2 on by 50% for one cycle, and turn FET 3 on. Turn on 25% of one cycle. At this time, the control circuit 60 performs control so that FET1, FET2, and FET3 are sequentially turned on, and any one of the switch elements is always turned on in one cycle. Thereby, the target light color can be obtained by adjusting the chromaticity.

  Thus, in the present embodiment, by controlling the number of LED arrays that are individually turned on / off, it becomes possible to control the color temperature and brightness more finely than in the first embodiment.

Embodiment 5 FIG.
In the present embodiment, differences from the first embodiment will be mainly described.

  FIG. 10 is a circuit diagram of lighting apparatus 10 according to the present embodiment.

  In the present embodiment, the power supply device 20 further includes a voltage detection circuit 70 and a protection circuit 80. The voltage detection circuit 70 divides the output voltage of the output constant current circuit 40 by the voltage detection resistor 71 and the voltage detection resistor 72 and applies the divided voltage to the protection circuit 80. The protection circuit 80 compares the output voltage with the reference voltage 82 by the comparator 81. The protection circuit 80 detects an open failure of the LED in either the LED array 1a or the LED array 2a by detecting the increase in the output voltage. The protection circuit 80 outputs an abnormality detection signal (predetermined signal) when detecting an open failure of the LED in either the LED array 1a or the LED array 2a. When an abnormality detection signal is output from the protection circuit 80, the control circuit 60 inputs this abnormality detection signal. Based on the input abnormality detection signal, the protection circuit 80 detects the LED open failure. At least one FET (eg, FET2) other than the FET (eg, FET1) connected to the array is controlled to be turned on.

  In the example of FIG. 4A, when any LED of the LED array 2a is in an open failure while the FET 2 is on, no current flows through the LED array 2a, so the LED array 2a is turned off. When the FET 1 enters an off period, the LED array 1a is also turned off.

  At this time, the output constant current circuit 40 increases its output voltage in order to flow a constant current to the LED. The voltage detection circuit 70 divides the output voltage by the voltage detection resistor 71 and the voltage detection resistor 72 and applies it to the comparator 81 of the protection circuit 80. The reference voltage 82 of the comparator 81 is set higher than the voltage across the LEDs connected in series in advance and lower than the output voltage of the output constant current circuit 40 when no load is applied. Therefore, the comparator 81 inverts the output voltage (from Low to Hi) and applies it to the control circuit 60 as an abnormality detection signal.

  The control circuit 60 determines that an LED has an open failure in the LED array 2a because the protection circuit 80 performs a protection operation (an abnormality detection signal is output) while the FET 2 is on-controlled. Then, the control circuit 60 controls the FET 2 to be always off and controls the FET 1 to be always on. Thereby, the LED array 1a can continue lighting.

  As described above, when only the FET 2 is on and the abnormality detection signal is output from the protection circuit 80, the control circuit 60 determines that an LED open failure has occurred in the LED array 2a. Then, the control circuit 60 controls the color temperature control circuit 50 so that the FET 1 is always turned on and the FET 2 is always turned off. Since the FET 1 is always on and the FET 2 is always off, the LED array 1a is always lit with a light output of 100%. As a result, the (appearance) brightness of the light emitted from the lighting device 100 is 100%, and the (appearance) color temperature is 3000K.

  Here, even if the LED open failure has occurred in the LED array 2a, and the LED open failure has occurred in the LED array 1a, the protection circuit 80 operates in the same manner as described above and outputs an abnormality detection signal. Output. As described above, if only the FET 2 is on when the abnormality detection signal is output from the protection circuit 80, the control circuit 60 may determine that an LED open failure has occurred in the LED array 2a. However, it may be assumed that an LED open failure has occurred once in the LED array 2a. That is, when an abnormality detection signal is output from the protection circuit 80, the control circuit 60 performs control to temporarily turn on the FET 1 once and always turn off the FET 2, and then the output of the abnormality detection signal from the protection circuit 80 continues. It is determined whether it is output. When it is determined that the abnormality detection signal is not continuously output, the control circuit 60 determines that the estimation that an LED open failure has occurred in the LED array 2a is correct. On the other hand, when the control circuit 60 determines that the abnormality detection signal is continuously output, an LED open failure has not occurred in the LED array 2a, but an LED open failure has occurred in the LED array 1a. Judge that Then, the control circuit 60 controls the color temperature control circuit 50 so that the FET 1 is always turned off and the FET 2 is always turned on. Since the FET 1 is always off and the FET 2 is always on, the LED array 2a is always lit with a light output of 100%. As a result, the (appearance) brightness of the light emitted from the illumination device 100 is 100%, and the (appearance) color temperature is 5000K.

  In this example, since the LED array 1a and the LED array 2a are set to have different emission colors as described above, it is possible to visually check which one of the LED array 1a and the LED array 2a has failed and repair the failure in a short time. Can be implemented.

  As in the example of FIG. 4B, the control circuit 60 controls the FET 1 to be turned on 50% of one cycle and the FET 2 is controlled to be turned on 50% of one cycle, or As in the example of FIG. 4C, the control circuit 60 controls the FET 1 to turn on 75% of one cycle, and controls the FET 2 to turn on 25% of one cycle. When any of the LEDs in the array 2a has an open failure, the control circuit 60 controls the FET 1 to be always turned on and controls the FET 2 to be always turned off as described above. Thereby, the LED array 1a can continue lighting. On the other hand, when one of the LEDs in the LED array 1a has an open failure, the control circuit 60 controls the FET 1 to be always off and controls the FET 2 to be always on. Thereby, the LED array 2a can continue lighting.

  Here, an example is shown in which an open failure occurs in the LED in a state where the switching operation is performed so that both FET1 and FET2 are alternately turned on. However, either one of FET1 or FET2 performs the switching operation. Even when an open failure occurs in the LED when the other is always on, the same operation can be used.

  As described above, according to the present embodiment, when one of the LEDs connected to the common output constant current circuit 40 has an open failure, the other LEDs can be protected. In such a case, a certain brightness can be ensured by turning on the other LEDs. That is, it is possible to prevent all LEDs from turning off and becoming completely dark when an open failure occurs in LEDs connected in series. Moreover, since the light from the illumination changes (for example, the color temperature changes), it can be visually confirmed which LED (light emitting unit) is in failure, and the failure repair can be performed in a short time.

  FIG. 11 is a timing chart showing an actual operation example of the lighting apparatus 10.

  The output constant current circuit 40 raises its output voltage to the maximum to allow current to flow in a no-load state, that is, when both FET1 and FET2 are off. Since this state is an abnormal state, the protection circuit 80 detects an abnormal voltage, and the control circuit 60 stops the operation of the output constant current circuit 40 in response to the detection. Therefore, in actual operation, after FET1 and FET2 have their on-time overlapped by time Td (a few percent of one period, or a ratio of more than 0% to 1% or less), only one of FET1 and FET2 is on. It is desirable to control to operate. Thereby, it is possible to avoid the protection circuit 80 from operating in a normal state (a state where there is no LED open failure or the like). Further, when the ON times of FET1 and FET2 are overlapped, for example, FET1 may be gradually turned off and FET2 may be gradually turned on. In this case, the total brightness of LED array 1a and LED array 2a is made substantially constant. be able to.

  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.

  1 FET, 1a LED array, 2 FET, 2a LED array, 3 FET, 3a LED array, 10 lighting device, 11 LED module, 12 substrate, 13a, 13b, 14 housing, 20 power supply device, 30 rectifying and smoothing circuit, 31 Diode bridge, 32 smoothing capacitor, 40 output constant current circuit, 41 FET, 42 resistance, 43 choke coil, 44 transistor, 45 diode, 46 current detection resistor, 47 constant current control circuit, 48 electrolytic capacitor, 50 color temperature control circuit, 51 FET drive circuit, 60 control circuit, 70 voltage detection circuit, 71 voltage detection resistor, 72 voltage detection resistor, 80 protection circuit, 81 comparator, 82 reference voltage, AC commercial AC power supply.

Claims (7)

A constant current power supply circuit for supplying a constant current;
Each of a plurality of light emitting units, each of which includes at least one LED, emits light by turning on the at least one LED with a constant current from the constant current power supply circuit. , One switch element connected in series to any one light emitting unit, turned on and turned on, and turned off and turned off;
Among the plurality of light emitting units, other switch elements connected in series to other light emitting units, turned on when turned on, and turned off when turned off,
A protective circuit that compares the output voltage of the constant current power supply circuit with a reference voltage and outputs an abnormality detection signal based on the comparison result;
By switching on / off of the one switch element at a predetermined cycle, the one light emitting unit blinks at the predetermined cycle, and by switching on / off of the other switch element at another cycle, the other light emission parts and a control circuit Ru was flashing the other period, said one switch element is controlled to be on, when they are controlled to turn off the other switching element, the abnormality detection signal from the protection circuit Is output, the control unit determines that the one light emitting unit has failed, controls the one switch element to be always off, and controls the other switch element to be always on. LED power supply. When the abnormality detection signal is output from the protection circuit when the control circuit controls the one switch element to ON and the other switch element to OFF, the one switch element If the abnormality detection signal is not continuously output from the protection circuit, it is determined that the one light emitting unit has failed, and the abnormality detection signal is continuously output from the protection circuit. when, the other is determined that the light emitting unit has failed, the one controlling the switching element always on, according to claim 1, characterized by controlling the normally-off the other switch element LED power supply. The control circuit is configured such that both of the one switch element and the other switch element have both switch elements between a time when only one switch element is turned on and a time when only the other switch element is turned on. as time turned on exists, LED power supply device according to claim 1 or 2, characterized in that to control the respective switching elements. The plurality of light emitting units emit different colors of light,
Wherein the control circuit, one of claims 1 to 3, characterized by controlling said plurality of light emitting portions whole in accordance with a toning signal for commanding emission color said one switch element and the other switch element The LED power supply device according to claim 1. Wherein the control circuit, to any one of claims 1 to 4, characterized by controlling the constant current to be supplied to the constant-current power supply circuit in response to the dimming signal for commanding the dimming degree of the entire plurality of light emitting portions LED power supply of description. LED power supply device according to any one of claims 1 to 5 ,
An LED lighting apparatus comprising the plurality of light emitting units. The one light emitting unit and the one switch element are arranged on the same substrate or casing, and the constant current power circuit is arranged on a substrate different from the substrate or a casing different from the casing. The LED lighting apparatus according to claim 6 , wherein

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