JP6170995B2 - Power supply circuit for lighting equipment - Google Patents

Description

  Embodiments of the present invention relate to a power supply circuit for a lighting device applied to a dimming system capable of adjusting the light intensity of the lighting device using, for example, an LED (light emitting diode).

  A dimmer for LED lighting is configured using a so-called phase control method in which the conduction angle of an AC power supply is changed by a switching element. (For example, refer to Patent Document 1 and Patent Document 2).

  The phase control dimmer generates noise depending on the power supply frequency when the switching element is turned on. For this reason, it is difficult to match the power supply circuit of the LED lighting device as a high impedance load with the dimmer. Further, when a plurality of dimmers are used, noises of the plurality of dimmers may interfere with each other through the power supply wiring, and the dimming performance may be deteriorated. For this reason, a noise prevention circuit is provided in the dimmer.

  However, the noise prevention circuit in the dimmer interferes with a noise prevention circuit included in a home appliance such as an IH heater having an inductance component, which causes a new problem that an interference sound is generated.

  Furthermore, reduction of EMI (Electro-Magnetic Interference) generated by the dimmer is required.

JP 2010-118229 A JP 2012-14953 A

  The present embodiment provides a power supply circuit for a lighting device that can reliably control light by suppressing the occurrence of noise.

The power supply circuit of the lighting device of the present embodiment is a power supply circuit of the lighting device that is connected to the light emitting element and supplies power to the light emitting element, and includes a first wiring and a second wiring that are supplied with AC power. A plurality of half cycles of the AC power supply connected to and supplied to the first wiring are removed corresponding to a zero cross point of the AC power supply, and a light intensity of the light emitting element is set to a first state. 1 command signal and a plurality of half cycles of the AC power supply are removed corresponding to the zero cross point of the AC power supply, and the luminous intensity of the light emitting element is set to a second state different from the first state. A second command signal and a plurality of half cycles of the AC power supply are removed corresponding to a zero cross point of the AC power supply, and unlike the first command signal and the second command signal, the first command Signal and A conversion circuit that receives a third command signal in a normal time during which the second command signal is not supplied and converts the AC power source including the first, second, and third command signals into a DC power source; A detection circuit for detecting a voltage of an AC power supply; and determining the first command signal, the second command signal, and the third command signal based on the voltage detected by the detection circuit; The control unit that generates the first or second pulse-modulated signal based on the command signal or the second command signal, the DC power output from the conversion circuit, and the control unit A current control circuit for controlling the light emitting element based on the first or second signal; and a memory for storing a brightness code of the light emitting element before the power is turned off. The above Change the brightness code stored in the memory, in accordance with the brightness code has been changed, to generate the pulsed width modulated first or second signal.

The lineblock diagram showing roughly an example of the light control system concerning a 1st embodiment. The flowchart shown in order to demonstrate operation | movement of the 1st control circuit shown in FIG. The wave form diagram which shows the operation | movement of each part of FIG. The flowchart shown in order to demonstrate operation | movement of the 2nd control circuit shown in FIG. The lineblock diagram showing roughly an example of the light control toning system concerning a 2nd embodiment. The lineblock diagram showing roughly an example of the light control toning system concerning a 3rd embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
(Overview)
The phase control type dimmer described above adjusts the luminous intensity (brightness) of the LED lighting device by changing the conduction angle of the switching element within a half cycle (180 °) of the sinusoidal AC waveform.

  On the other hand, the dimming system according to the present embodiment does not change the conduction angle of the half cycle of the sine wave AC waveform, but instructs the power supply circuit of the LED lighting device to increase or decrease the luminous intensity instead of changing the conduction angle of the half cycle. The command signal is transmitted. This command signal is generated by removing half of several cycles of several cycles of the AC waveform. That is, when there is no half cycle waveform of the AC waveform (when the half cycle voltage is zero level), the data is “0”, when there is a half cycle waveform of the AC waveform (when there is a half cycle voltage), the data is “1”. The first command signal for increasing the luminous intensity or the second command signal for decreasing the luminous intensity is generated based on the rule “. These first and second command signals are supplied to the power supply circuit of the LED lighting device. The power supply circuit of the LED lighting device generates a pulse width modulation (PWM) signal based on the first and second command signals, and adjusts the luminous intensity of the LED lighting device.

(Constitution)
FIG. 1 relates to the first embodiment and schematically shows, for example, a two-wire dimming system 10. The dimming system 10 includes a dimmer 11 and an LED lighting device 20. Although LED lighting apparatus 20 has shown the case where the power supply circuit 31 and LED21 are included, it is not limited to this, The power supply circuit 31 and LED21 can also be made into a separate structure.

  The dimmer 11 is inserted and connected to the wiring 13 connected to one end of the AC power supply 12, and the power supply circuit 31 of the LED lighting device 20 is connected to the wiring 13 connected to one end of the AC power supply 12 and the AC power supply 12. It is connected to the wiring 14 connected to the end. The dimmer 11 communicates first, second, and third commands according to a communication format described later with the power supply circuit 31 and adjusts the luminous intensity of the LED lighting device 20.

  In the dimmer 11, a bidirectional switching element, for example, a triac 15 is inserted and connected to the wiring 13. A power generation circuit 16 is connected to both ends of the triac 15. The power supply generation circuit 16 includes a rectifier circuit 16a and a regulator circuit 16b, and generates a DC power supply during the off period of the triac 15. The rectifier circuit 16a is constituted by a full-wave rectifier circuit, for example. The regulator circuit 16b includes, for example, a transistor, a Zener diode, a plurality of capacitors, a plurality of resistors, and a known three-terminal regulator. The configuration of the power generation circuit 16 is not limited to this.

  The DC voltage output from the regulator circuit 16b is supplied as a power source to the first control circuit 17 and the zero cross detection circuit 18. Further, the output voltage of the rectifier circuit 16 a is supplied to the zero cross detection circuit 18.

  The zero cross detection circuit 18 detects the zero cross point of the power supply voltage based on the level of the voltage supplied from the rectifier circuit 16a. The zero cross detection circuit 18 is constituted by, for example, a transistor. One end of the current path of the transistor is connected to the regulator circuit 16b, and power is supplied from the regulator circuit 16b. The other end of the current path of the transistor is grounded. A full-wave rectified output is supplied to the gate of this transistor. When there is a full-wave rectified output, the transistor is turned on, and one end of the current path is at a low level. When the full-wave rectified output becomes zero potential, the transistor is turned off, and one end of the current path is at a high level. This high level signal is supplied to the first control circuit 17 as a signal indicating the zero cross point.

  The zero cross detection circuit 18 is not limited to this. For example, the output voltage of the rectifier circuit 16a and a constant threshold voltage may be compared by a comparator.

  The first control circuit 17 is connected to first and second switches UP and DN. The first switch UP is, for example, a switch for instructing an increase in luminous intensity, and the second switch DN is, for example, a switch for instructing a decrease in luminous intensity. The first and second switches UP and DN are constituted by push button switches, for example. The first and second switches UP and DN output one high level signal when a button (not shown) is pressed and released, and output a high level signal, for example, while the button is continuously pressed.

  The first control circuit 17 generates a signal for controlling the triac 15 based on the signal supplied from the first switch UP or the second switch DN and the output signal of the zero cross detection circuit 18. The first control circuit 17 is constituted by a microcomputer, for example. This microcomputer comprises a CPU as a central processing unit (not shown), a volatile memory as a work memory, and a nonvolatile memory. The operation of the first control circuit 17 is controlled by a program stored in the nonvolatile memory.

  As described above, the dimmer 11 according to the first embodiment is based on the rule that data is “0” when there is no half-cycle waveform, and data “1” when there is no half-cycle, with a half cycle of the AC waveform as a unit. First and second command signals are generated. That is, the dimmer 11 generates a first command signal for increasing the luminous intensity based on the instruction of the first switch UP, and the first dimmer for decreasing the luminous intensity based on the instruction of the second switch DN. 2 command signals are generated.

  The first command signal is composed of, for example, 2.5 cycles of an AC waveform, and two half-cycle waveforms are removed from the 2.5 cycles. For this reason, the first command signal is, for example, “11010”.

  The second command signal is composed of, for example, three cycles of an AC waveform, and two half-cycle waveforms out of the three cycles are removed. For this reason, the second command signal is, for example, “110110”.

  Further, as described above, the dimmer 11 generates power for the first control circuit 17 during the off period of the triac 15. For this reason, data “0” having no half cycle of the AC waveform is required periodically. For this reason, the triac 15 outputs the third command signal at the normal time when the first and second command signals for dimming are not transmitted to the power supply circuit 31.

  The third command signal is composed of, for example, 1.5 cycles of an AC waveform, and one half cycle of 1.5 cycles is removed. For this reason, the third command signal is, for example, “101”. The triac 15 is controlled so as to repeatedly output the third command signal in the normal state.

  The patterns of the first, second, and third command signals are not limited to this, and can be modified.

  The triac 15 outputs the first and second command signals and the normal third command signal to instruct the power supply circuit 31 to perform dimming. Therefore, the first control circuit 17 generates a signal for controlling the traac 15 based on the output signals of the first and second switches UP and DN and the zero cross detection circuit 18.

  Specifically, the first control circuit 17 controls the triac 15 to generate the first, second, and third command signals and the third command signal at the normal time. Control signal is generated. That is, the first control circuit 17 generates, for example, the first control signal “11010” corresponding to the first command signal “11010”, and corresponds to, for example, the second command signal “110110”. 2 control signal “110110” is generated, and for example, a third control signal “101” is generated in response to the third command signal “101”. The patterns of the first, second, and third control signals are not limited to this, and can be modified.

  The triac 15 is controlled according to the first to third control signals supplied from the first control circuit 17 and outputs any of the first, second, and third command signals.

  On the other hand, the power supply circuit 31 of the LED lighting device 20 includes an AC / DC conversion circuit 32, a detection circuit 33, a second control circuit 34, and a constant current circuit 35.

  The AC / DC conversion circuit 32 is connected to the wirings 13 and 14 connected to the AC power supply 12 and converts the AC voltage supplied from the triac 15 into a DC voltage. The converted DC voltage is supplied to the constant current circuit 35.

  The detection circuit 33 receives data “0” from the AC voltage including the first and second command signals output from the triac 15 supplied via the AC / DC conversion circuit 32 and the third command signal in the normal state. "1" (voltage presence / absence) is detected. That is, the detection circuit 33 detects the voltage of the AC voltage output from the triac 15 at a specified time according to a predetermined threshold voltage, and detects data “0” or “1”. The specified time is when, for example, 1 ms has elapsed from the zero cross, and the threshold voltage is, for example, a voltage in the vicinity of 0V. The prescribed time and threshold voltage are not limited to this, and may be determined in consideration of frequency fluctuations and voltage fluctuations of the AC power supply.

  Similar to the first control circuit 17, the second control circuit 34 includes, for example, a microcomputer, a volatile memory, a nonvolatile memory, and the like. The operation of the second control circuit 34 is controlled by a program stored in a nonvolatile memory (not shown).

  Further, the second control circuit 34 includes a rewritable memory 34a such as an EPROM and a PWM circuit (not shown).

  The memory 34a stores, for example, a brightness code. This brightness code is, for example, a value obtained by dividing one period of a PWM signal into 10 stages or 46 stages.

  Specifically, when the time width of one cycle of the PWM signal is divided into 10 stages, the ON time of the PWM signal at each duty ratio is, for example, as follows. 50 μs, 150 μs, 250 μs, 350 μs, 450 μs, 550 μs,... 950 μs. A code obtained by coding the on-time is a brightness code, and a code corresponding to, for example, 450 μs as an intermediate value is stored in the memory 34a as an initial value.

  The division ratio can be set based on the accuracy of light control. For example, in the normal mode, it is divided into the above 10 steps, and in the detailed mode in which more detailed light control is performed, it is divided into, for example, 46 steps. However, it is not limited to this. In the normal mode, the light intensity is adjusted in 10 steps according to the first and second command signals, and in the detailed mode, the light intensity is adjusted in 46 steps according to the first and second command signals.

  The second control circuit 34 detects the first and second command signals and the normal third command signal from the data “0” or “1” supplied from the detection circuit 33, and detects the detected first, The brightness code is changed, for example, one step at a time according to the second command signal, and a PWM signal is generated according to the changed brightness code. Specific operations of detecting the first and second command signals, changing the brightness code, and generating the PWM signal will be described later. The PWM signal output from the second control circuit 34 is supplied to the constant current circuit 35.

  The constant current circuit 35 is constituted by, for example, a switching power supply, and a DC voltage according to the first and second command signals supplied from the AC / DC conversion circuit 32 or a third command signal in the normal state, In response to the PWM signal supplied from the control circuit 34, the LED 21 is driven at a constant voltage by a current proportional to the duty ratio of the PWM signal. Therefore, the luminous intensity of the LED 21 is controlled based on the first and second command signals.

(Operation of the dimmer 11)
FIG. 2 shows the operation of the first control circuit 17. The operation of the dimming system shown in FIG. 1 will be described with reference to FIG.

  The first control circuit 17 is driven by the power supply supplied from the regulator circuit 16b. In the initial state, the first control circuit 17 is synchronized with the signal indicating the zero cross point supplied from the zero cross detection circuit 18, and the third control signal “101”. Is generated (S11). This control signal is supplied to the gate electrode of the triac 15. Therefore, the triac 15 outputs the third command signal 101 ″ according to the third control signal.

  FIG. 3A shows the AC voltage supplied to one end of the triac 15. When the normal third control signal “101” is supplied to the gate electrode of the triac 15, the triac 15 is turned on when the control signal is “1” and turned off when the control signal is “0”.

  FIG. 3B shows an output waveform of the triac 15 according to the third control signal. That is, from the other end of the triac 15, the third command signal “101” from which half cycles of the AC voltage are periodically removed is repeatedly output according to the third control signal “101”.

  In this state, the first control circuit 17 determines whether or not the first switch UP has been pressed (S12). If the first switch UP has not been pressed, has the second switch DN been pressed? Is discriminated (S13).

  If it is determined in step S12 that the first switch UP has been pressed, the first control circuit 17 generates a first control signal “11010” (S14). That is, the first control circuit 17 generates the first control signal “11010” in synchronization with the signal indicating the zero cross point supplied from the zero cross detection circuit 18.

  When the first switch UP is continuously pressed, the first control circuit 17 performs the first control signal “11010” and the third control signal “101” while the first switch UP is pressed. "Is repeatedly generated. The reason why the first control signal and the third control signal are repeatedly generated is that, as will be described later, a command cannot be identified unless three “1” s are consecutive.

  The triac 15 is controlled to be turned on or off according to the first control signal supplied from the first control circuit 17 and outputs a first command signal “11010” corresponding to the first control signal.

  FIG. 3C shows an output waveform of the triac 15 when the first switch UP is pressed once in a normal state. As shown in FIG. 3C, the first command signal “11010” is output after the third command signal “101” in the normal time, and further, the third command signal “101” in the normal time. Is shown. That is, in a normal state, the signal pattern of the output waveform of the triac 15 when the first switch UP is pressed once is, for example, “... 10111010101.

  On the other hand, if it is determined in step S13 that the second switch DN has been pressed, the first control circuit 17 generates the second control signal “110110” (S15). That is, the first control circuit 17 generates the second control signal “110110” in synchronization with the signal indicating the zero cross point supplied from the zero cross detection circuit 18.

  When the second switch DN is continuously pressed, the first control circuit 17 performs the second control signal “110110” and the third control signal “101” while the second switch DN is pressed. "Is repeatedly generated.

  The triac 15 is controlled to be turned on and off in accordance with the second control signal supplied from the first control circuit 17 and outputs a second command signal “110110” corresponding to the second control signal. For this reason, in the normal state, the signal pattern of the output waveform of the triac 15 when the second switch DN is pressed once is, for example, “... 110110110101.

(Operation of power supply circuit 31)
In the power supply circuit 31, the AC / DC conversion circuit 32 converts the AC power supplied from the triac 15 into a DC power. The detection circuit 33 compares the AC voltage from the triac 15 supplied via the AC / DC conversion circuit 32 with the threshold voltage, and detects data “0” or “1”. The data “0” or “1” detected by the detection circuit 33 is supplied to the second control circuit 34.

  The second control circuit 34 determines whether the first or second command signal is based on the data “0” or “1” supplied from the detection circuit 33, and corresponds to the determined signal. A PWM signal is generated.

  FIG. 4 shows an example of the operation of the second control circuit 34.

  The second control circuit 34 reads the brightness code stored in the memory 34a at the time of activation (S21). This brightness code is the brightness code stored in the memory 34a before the power is turned off.

  The second control circuit 34 calculates a duty ratio based on the brightness code read from the memory 34a, and generates a PWM signal based on the duty ratio (S22). The generated PWM signal is supplied to the constant current circuit 35. The constant current circuit 35 drives the LED 21 with a constant voltage by a current proportional to the duty ratio of the PWM signal. Accordingly, the LED 21 is turned on at the light intensity just before turning off.

  Thereafter, the second control circuit 34 detects the command identification unit (S23) based on the data supplied from the detection circuit 33. That is, whether the data “0” or “1” included in the AC voltage is a command signal is determined based on the command identification unit. The command identification unit is data “111”. Subsequent data including data “111” is a command signal. Therefore, the second control circuit 34 determines whether or not the output of the detection circuit 33 is data “111”.

  When the data “111” is determined, the second control circuit 34 determines whether the sent command is the first command signal or the second command signal (S24, S25). . That is, of the three “1” s of the data “111”, the data after the second “1” is a command, and whether this data is the first command signal or the second command signal. To be judged.

  Specifically, as shown in FIG. 3C, when the data from the detection circuit 33 is “... 10111010101...”, The second “1” and subsequent data “ 11010 "is a command. That is, in the case of this data, it is determined that it is the first command signal.

  If it is determined in step S24 that the data is the first command signal, the current brightness code described above is incremented by "+1" (S26). That is, the 10-level brightness code is increased by one level.

  If it is determined in step S25 that the data is the second command signal, the brightness code is set to "-1" (S27). That is, the 10-level brightness code is decreased by one level. The brightness code changed in steps S26 and S27 is stored in the memory 34a (S28).

  Thereafter, control is transferred to step S22, a duty ratio is calculated according to the changed brightness code, and a PWM signal is generated based on the duty ratio. This PWM signal is supplied to the constant current circuit 35.

  The constant current circuit 35 controls the LED 21 according to the PWM signal. For this reason, the luminous intensity of the LED 21 is adjusted in accordance with the first command signal or the second command signal.

  Note that the second control circuit 34 changes the brightness code to “+1” or more when the first command signal and the third command signal are continuously supplied, and the second command signal and the third command signal. When the command signal is continuously supplied, the brightness code is changed to “−1” or more. For this reason, the luminous intensity of the LED 21 is adjusted more greatly.

  When the power is turned off in the above state, the current brightness code is stored in the memory 34a. Therefore, when the power is turned on next time, it is possible to reproduce the brightness before turning off.

  The timing for storing the brightness code in the memory 34a is not limited to the above example, and may be after, for example, calculating the duty ratio and outputting the PWM signal.

(Effects of the first embodiment)
According to the first embodiment, the first control circuit controls the presence / absence of a half cycle of the AC waveform to increase the luminous intensity in accordance with the instructions of the first and second switches UP and DN. The control signal, the second control signal for decreasing the luminous intensity, and the third control signal for generating the power supply of the dimmer are generated to control the triac 15. In accordance with the first, second, and third control signals, the triac 15 is turned on and off at a zero cross point where the voltage becomes zero every half cycle of the AC waveform, and is not controlled during the half cycle of the AC waveform. For this reason, generation | occurrence | production of noise can be suppressed.

  Moreover, since the light control system of this embodiment can suppress generation | occurrence | production of noise, the noise prevention circuit containing an inductance component is not required. For this reason, it is possible to prevent the generation of interference sound with electrical products such as IH heaters. In addition, since a noise prevention circuit including an inductance component is not required, the loss is small and the amount of heat generation can be suppressed. Therefore, the maximum load capacity of the dimmer 11 can be improved.

  Furthermore, since the triac 15 is controlled at the zero cross timing, no inrush current is repeatedly generated. For this reason, even if a plurality of dimmers are connected to the same power source, for example, interference with other dimmers can be prevented and appropriate dimming can be performed. In addition, since no inrush current is generated, the triac can be prevented from being destroyed.

  Further, the triac 15 is controlled to output the third command signal “101” during normal operation. Therefore, it is possible to generate a power supply for driving the first control circuit 17 in the two-wire dimming system.

  Further, the triac 15 generates first, second, and third command signals according to the first, second, and third control signals, and sends the first, second, and third command signals to the LED lighting device 20. The power is supplied to the power circuit 31. For this reason, a low noise power line conveyance is possible using an alternating voltage. In addition, since the command signal is constituted by the presence or absence of a half cycle of the AC waveform, control is easy.

  The second control circuit 34 of the power supply circuit 31 changes the brightness code in accordance with the first and second command signals, generates a PWM signal corresponding to the brightness code, and supplies the PWM signal to the constant current circuit 35. doing. The changed brightness code is stored in the memory 34a. For this reason, it is possible to reproduce the light intensity before the light is turned off when the light is turned on again after the light is turned off.

(Second Embodiment)
In the first embodiment, the dimming system has been described. However, it is also possible to apply the first embodiment to toning for adjusting the emission color of the LED lighting device. That is, the LED lighting device capable of color matching includes, for example, two LEDs having different emission colors, and controls the emission color of the LED lighting device by adjusting the luminous intensity of these LEDs. That is, since the toning is an application of dimming, the toning can be performed using the dimming technique according to the first embodiment.

  FIG. 5 shows a two-wire dimming toning system 10 according to the second embodiment. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and only different parts will be described.

  As shown in FIG. 5, the LED lighting device 40 includes a first LED 21a having a first emission color, for example, daylight color, and a second LED 21b having a second emission color, for example, a light bulb color.

  The power supply circuit 31 includes a first constant current circuit 35a corresponding to the first LED 21a and a second constant current circuit 35b corresponding to the second 21b.

  On the other hand, in addition to the first and second switches UP and DN, the first control circuit 17 is provided with third and fourth switches CLa and CLb for instructing toning. The first control circuit 17 generates fourth and fifth control signals for controlling the emission color according to the operation of the third and fourth switches CLa and CLb. Similar to the first, second, and third control signals, the fourth and fifth control signals are generated by removing a plurality of half cycles of the AC waveform based on the zero cross point of the AC power supply.

  The triac 15 generates fourth and fifth command signals in accordance with the fourth and fifth control signals. The fourth and fifth command signals may be different from the first, second, and third command signals. Specifically, the fourth command signal is “11011010”, for example, and the fifth command signal is “110110110”, for example.

  In the power supply circuit 31, the detection circuit 33 detects AC voltage data “0” or “1” from the triac 15 supplied via the AC / DC conversion circuit 32.

  The second control circuit 34 stores the first and second brightness codes in the memory 34a. The first and second brightness codes are the same as those in the first embodiment. The first brightness code is for the first LED 21a, and the second brightness code is for the second LED 21b. Further, the second control circuit 34 includes first and second PWM circuits (not shown). The first PWM circuit is for the first LED 21a, and the second PWM circuit is for the second LED 21b.

  Based on the data “0” or “1” supplied from the detection circuit 33, the second control circuit 34 determines whether it is the first or second command signal or the fourth or fifth command signal. Determine. The determination method is the same as in the first embodiment.

  When determining that the command signal is the first command signal, the second control circuit 34 adds “+1” to both the first and second brightness codes and determines that the command signal is the second command signal. If the first and second brightness codes are both “−1” and determined to be the fourth command signal, the first brightness code is “+1” and the second brightness code is “ If it is -1 "and it is determined that it is the fifth command signal, the first brightness code is set to" -1 "and the second brightness code is set to" +1 ".

  The second control circuit 34 calculates a first duty ratio from the first brightness code, and the first PWM circuit generates a first PWM signal based on the first duty ratio. The second control circuit 34 calculates a second duty ratio from the second brightness code, and the second PWM circuit generates a second PWM signal based on the second duty ratio.

  The first and second constant current circuits 35a and 35b adjust the light emission amounts of the first and second LEDs 21a and 21b based on the first and second PWM signals. Thereby, the emission color of the LED lighting device 20 is adjusted according to the fourth and fifth command signals, and the luminous intensity is adjusted according to the first and second command signals.

  Specifically, when it is determined that the command signal is the first command signal, the second control circuit 34 is increased by one step from the current duty ratio according to the first and second brightness codes. First and second duty ratios are calculated, and the first and second PWM circuits generate first and second PWM signals based on the first and second duty ratios. Therefore, the first and second constant current circuits 35a and 35b both increase the luminous intensity of the first and second LEDs 21a and 21b by one step based on the first and second PWM signals.

  Further, when it is determined that the command signal is the second command signal, the second control circuit 34 determines the first and second values that are one step lower than the current duty ratio in accordance with the first and second brightness codes. The second duty ratio is calculated, and the first and second PWM circuits generate the first and second PWM signals based on the first and second duty ratios. Therefore, the first and second constant current circuits 35a and 35b decrease the luminous intensity of the first and second LEDs 21a and 21b by one step based on the first and second PWM signals.

  When it is determined that the command signal is the fourth command signal, the second control circuit 34 calculates the first duty ratio that is one step higher than the current duty ratio in accordance with the first brightness code. Then, according to the second brightness code, a second duty ratio that is one step down from the current duty ratio is calculated. The first and second PWM circuits generate first and second PWM signals based on the first and second duty ratios. Therefore, the first constant current circuit 35a increases the luminous intensity of the first LED 21a by one step based on the first PWM signal, and the second constant current circuit 35b is based on the second PWM signal. The luminous intensity of the second LED 21b is decreased by one step.

  If it is determined that the command signal is the fifth command signal, the second control circuit 34 calculates the first duty ratio that is one step down from the current duty ratio according to the first brightness code. Then, a second duty ratio that is one step higher than the current duty ratio is calculated according to the second brightness code. The first and second PWM circuits generate first and second PWM signals based on the first and second duty ratios. For this reason, the first constant current circuit 35a decreases the luminous intensity of the first LED 21a by one step based on the first PWM signal, and the second constant current circuit 35b determines the first constant current circuit 35a based on the second PWM signal. The luminous intensity of the second LED 21b is increased by one step.

  According to the second embodiment, the first control circuit 17 generates the fourth and fifth control signals according to the third and fourth switches CLa and CLb, and the triac 15 includes the fourth and fifth switches. According to the control signal, the fourth and fifth command signals are generated by removing a plurality of half cycles of the AC waveform based on the zero cross point of the AC signal. The second control circuit 34 of the power supply circuit 31 generates first and second PWM signals having different duty ratios based on the fourth and fifth command signals, and the first and second constant currents are generated. The circuits 35a and 35b control the outputs of the first and second LEDs 21a and 21b according to the output voltage of the AC / DC conversion circuit 32 and the first and second PWM signals. For this reason, as in the first embodiment, it is possible to perform color matching of the LED lighting device 20 while suppressing the generation of noise.

(Third embodiment)
In the first and second embodiments, one LED lighting device is controlled by one dimmer. On the other hand, 3rd Embodiment demonstrates the case where a several LED lighting apparatus is controlled by one dimmer.

  When a plurality of LED lighting devices are controlled by one dimmer, an address signal is used to identify the plurality of LED lighting devices.

  FIG. 6 shows a third embodiment. In FIG. 6, the same parts as those in FIG.

  The dimmer 11 is connected to the first and second LED lighting devices 20-1 and 20-2. The configurations of the first and second LED lighting devices 20-1 and 20-2 are substantially the same as those in the first embodiment. The number of LED lighting devices is not limited to two.

  The dimmer 11 has a fifth switch AD for instructing addresses of the first and second LED lighting devices 20-1 and 20-2. The fifth switch AD is connected to the first control circuit 17. The fifth switch AD is composed of, for example, a digital switch. When the first LED lighting device 20-1 is designated, for example, the fifth switch AD is set to “1”, for example, and when the second LED lighting device 20-2 is designated, For example, it is set to “2”.

  A communication format including a command signal and an address signal output from the dimmer 11 is, for example, as follows.

“1101xxxx10xxx”
here,
“11” is a command identification unit,
“01” is dummy data,
“Xxxx” is the address part,
“10” is dummy data,
“Xx” is a command part.

  As described above, the command identification unit is data for distinguishing the command signal from other data.

  The dummy data is data necessary for generating the power supply of the dimmer 11.

  The command portion is set, for example, to “10” when the luminous intensity is increased (increased) by one level, for example, “110” when decreased (decimated) by one level.

  In the address section, an address for designating one of the first and second LED lighting devices 20-1 and 20-2 is set. The address part may be data in which two or more “1” s are not consecutive in order to be distinguished from the command identification part, and “0” may be consecutive if the power of the dimmer 11 can be generated.

  The first control circuit 17 includes first to third control signals and an address control signal according to the operation of the first, second, and fifth switches UP, DN, and AD, and outputs a control signal according to the communication format. Generate. This generated control signal is supplied to the triac 15. The triac 15 is turned on and off in accordance with the control signal, and supplies an alternating voltage including an address signal and a command signal to the first and second LED lighting devices 20-1 and 20-2.

  The second control units 34-1 and 34-2 of the first and second LED lighting devices 20-1 and 20-2 receive address signals from data supplied from the corresponding detection circuits 33-1 and 33-2. Is determined. As a result, when it is determined that it is its own address, the command signal is determined, and the constant current circuit 35-1 or 35-2 is controlled according to the data of this command signal. That is, when the address indicates the first LED lighting device 20-1, the constant current circuit 35-1 is controlled by the second control circuit 34-1, and the LED 21-1 is dimmed. When the address indicates the second LED lighting device 20-2, the constant current circuit 35-2 is controlled by the second control circuit 34-2, and the LED 21-2 is dimmed.

  According to the third embodiment, in the dimmer 11, the address signal and the command signal are generated by controlling the half cycle of the waveform of the AC voltage according to the address control signal and the first to third control signals. 1 and the second control units 34-1 and 34-2 of the second LED lighting devices 20-1 and 20-2 receive address signals from data supplied from the corresponding detection circuits 33-1 and 33-2. If it is determined that the address is its own address, the command signal is determined, and the constant current circuit is controlled according to the determined command signal. Therefore, it is possible to dimm multiple LED lighting devices with low noise.

(Fourth embodiment)
In the first to third embodiments, the two-wire dimming system or the dimming toning system has been described. However, the present invention is not limited to this, and the first to third embodiments can be applied to a four-wire dimming system or a dimming toning system.

  In the case of a 4-wire dimming system or a dimming toning system, it is not necessary to generate the third control signal and the third command signal in order to generate the power supply of the first control circuit 17. Therefore, the normal data is “1”, which is the sine wave itself. Further, by setting the first command signal to “010”, for example, and the second command signal to “0110”, for example, dimming can be performed by the same operation as described above. Color adjustment is also possible by setting the fourth and fifth commands.

  In addition, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  DESCRIPTION OF SYMBOLS 10 ... Dimming system, 11 ... Dimmer, 12 ... AC power supply, 15 ... Triac, 16 ... Power supply generation circuit, 17 ... 1st control circuit, 18 ... Zero cross detection circuit, UP ... 1st switch, DN ... 2nd switch, 20, 20-1, 20-2 ... LED lighting device, 21 ... LED, 21a ... 1st LED, 21b ... 2nd LED, 31 ... power supply circuit, 32 ... AC / DC conversion circuit, 33 ... Detection circuit, 34 ... Second control circuit, 35 ... Constant current circuit, 35a ... First constant current circuit, 35b ... Second constant current circuit, CLa, CLb ... Third and fourth switches, AD ... Fifth switch.

Claims (3)

A power supply circuit of a lighting device connected to a light emitting element and supplying power to the light emitting element,
A first wiring and a second wiring supplied with AC power are connected, and a plurality of half cycles of the AC power supplied to the first wiring are removed corresponding to a zero cross point of the AC power, A first command signal for setting the luminous intensity of the light emitting element to a first state and a plurality of half cycles of the AC power supply are removed corresponding to a zero cross point of the AC power supply, and the luminous intensity of the light emitting element is changed. A second command signal for setting a second state different from the first state, and a plurality of half cycles of the AC power supply are removed corresponding to a zero cross point of the AC power supply, and the first command Unlike the signal and the second command signal, the first command signal and the third command signal at the normal time when the second command signal is not supplied are received, and the first, second, and third command signals are received. Includes command signal A conversion circuit for converting the AC power to a DC power supply,
A detection circuit for detecting the voltage of the AC power supply;
Based on the voltage detected by the detection circuit, the first command signal, the second command signal, and the third command signal are discriminated, and the first command signal or the second command signal is determined. A control unit for generating a pulse width modulated first or second signal,
A DC power source output from the conversion circuit, a current control circuit for controlling the light emitting element based on the first or second signal supplied from the control unit,
A memory for storing a brightness code of the light emitting element before the power is turned off;
Comprising
The control unit changes the brightness code stored in the memory, and generates the first or second signal that is pulse-width modulated in accordance with the changed brightness code. Power supply circuit. The light emitting element includes a first light emitting element having a first light emitting color and a second light emitting element having a second light emitting color,
In the conversion circuit, a plurality of half cycles of the AC power supply are removed corresponding to a zero cross point of the AC power supply, a fourth command signal different from the first to third command signals, and a plurality of the AC power supplies The half cycle is removed corresponding to the zero cross point of the AC power source, receives the fifth command signal different from the first to fourth command signals, and includes the first to fifth command signals. Convert power to DC power,
The current control circuit includes a first constant current circuit corresponding to the first light emitting element, and a second constant current circuit corresponding to the second light emitting element,
In response to the fourth command signal, the control unit supplies the first constant current circuit with a third signal having a pulse width modulation larger than a current duty ratio, and supplies the second constant current circuit with the third signal. A fourth signal having a pulse width modulation smaller than the current duty ratio is supplied, and a fifth pulse width modulated fifth signal smaller than the current duty ratio is supplied to the first constant current circuit in response to the fifth command signal. The second constant current circuit is supplied with a pulse width modulated sixth signal larger than the current duty ratio ,
The memory stores a first brightness code of the first light emitting element and a second brightness code of the second light emitting element before the power is turned off,
The control unit changes the first brightness code and the second brightness code stored in the memory in response to the fourth command signal, and the changed first brightness code and According to the second brightness code, the third signal having a pulse width modulation larger than a current duty ratio is supplied to the first constant current circuit, and the second constant current circuit is supplied with a current duty ratio. Supplying the fourth signal with a small pulse width modulation, and changing the first brightness code and the second brightness code stored in the memory in response to the fifth command signal; In accordance with the changed first brightness code and the second brightness code, the first constant current circuit is supplied with the fifth signal having a pulse width modulated smaller than a current duty ratio, 2 constant current circuit Power supply circuit of the lighting apparatus according to claim 1, wherein the supply current of said sixth signal which are greater pulse width modulation than the duty ratio. An address signal connected to the first and second light-emitting elements and having a plurality of half cycles of the AC power supply removed in correspondence with a zero-cross point of the AC power supply, and a plurality of half cycles of the AC power supply being The first or second command signal removed corresponding to the zero cross point, and the address signal, the first command signal, and the second command signal are not generated. A half cycle is removed corresponding to the zero cross point of the AC power supply, receives the dummy data different from the address signal, the first command signal, and the second command signal, and the first and second light emitting elements. A power supply circuit for a lighting device comprising first and second power supply circuits for supplying power to
The first power supply circuit includes:
The AC line including the address signal, the first or second command signal, and dummy data supplied to the first line is connected to the first line and the second line to which the AC power is supplied. A first conversion circuit for converting a power source into a DC power source;
The address signal included in the AC power supply, the first or second command signal, and dummy data are discriminated, and when the address signal corresponds to the first power supply circuit, the first command signal or A first control unit that generates a first or second pulse-modulated signal based on the second command signal;
A first current control circuit that controls the first light emitting element based on a DC power output from the first conversion circuit and the first or second signal supplied from the first control unit. When,
Including
The second power supply circuit includes:
The first wiring and the second wiring to which the AC power is supplied are connected and include the address signal, the first or second command signal, and dummy data supplied to the first wiring. A second conversion circuit for converting the AC power source into a DC power source;
The address signal included in the AC power supply, the first or second command signal, and dummy data are discriminated, and when the address signal corresponds to the second power supply circuit, the first command signal or A second control unit that generates a third or fourth pulse-modulated signal based on the second command signal;
A second current control circuit that controls the second light emitting element based on the DC power output from the second conversion circuit and the third or fourth signal supplied from the second control unit. When,
Equipped with,
The first power supply circuit includes:
A first memory for storing a first brightness code of the first light emitting element before the power is turned off;
The first control unit determines the address signal, the first or second command signal, and dummy data included in the AC power supply, and the address signal corresponds to the first power supply circuit. The first brightness code stored in the first memory is changed based on the first command signal or the second command signal, and a pulse is generated according to the changed first brightness code. Generating the width-modulated first or second signal;
The second power supply circuit includes:
A second memory for storing a second brightness code of the second light emitting element before the power is turned off;
The second control unit determines the address signal, the first or second command signal, and dummy data included in the AC power source, and the address signal corresponds to the second power circuit. The second brightness code stored in the second memory is changed based on the first command signal or the second command signal, and a pulse is generated according to the changed second brightness code. A power supply circuit for a lighting device, wherein the third or fourth signal subjected to width modulation is generated .

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