JP2010192267A - Dimmer, lighting device, and illumination control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply power necessary for stable operation of a lighting device while transmitting a dimming signal through a power line. <P>SOLUTION: A bidirectional thyristor T54 (a switching element) is interposed in the power line 811 for supplying AC power to the lighting device 300. A zero cross detection circuit 120 detects a zero cross of a voltage of the AC power supply AC. A switch control circuit 140 provides: a dimming degree instruction period in which a period for making conductive the bidirectional thyristor T54 and a period for insulating the bidirectional thyristor T54 are included in one half cycle period; and a power supply period in which the bidirectional thyristor T54 continues to be made conductive during the one half cycle period. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lighting control system having a lighting fixture with a dimming function.

In an illumination control system that turns on a light source such as an incandescent lamp, the phase of the conduction angle of the power supplied to the light source is phase-controlled to cut out part of the power waveform and adjust the power supplied to the light source. There is a dimming method that changes the brightness of the.
On the other hand, in the case of a lighting device that lights a light source such as a discharge lamp such as a fluorescent lamp or an LED, simply reducing the power supplied to the lighting device results in unstable operation or flickering. . For this reason, a dimming signal line is provided separately from the power supply line for supplying power to the lighting device, and the dimming signal is transmitted to the lighting device via the dimming signal line.

Japanese Utility Model Publication No. 6-11298

When the dimming signal line is provided separately from the power supply line, the wiring to the lighting device increases, so that the cost of wiring work increases. In addition, when an existing lighting fixture is replaced with a lighting fixture with a dimming function, a work for adding wiring is required.
The present invention has been made to solve the above-described problems, for example, and has an object to stably operate a lighting device while transmitting a dimming signal through a power supply line.

The light control device according to the present invention is a light control device for instructing the light control degree to the lighting device.
A switching element interposed in a power line for supplying AC power to the lighting device;
A zero cross detection circuit for detecting a zero cross of the voltage of the AC power supplied from the power line;
Based on the zero cross detected by the zero cross detection circuit, a period from when the voltage of the AC power is zero crossed until the next zero cross is defined as a half cycle period, and the switching element is turned on in one half cycle period. A dimming degree indicating period for providing a period, a period for insulating the switching element, and a switch control circuit for providing a power supply period for conducting the switching element continuously for one half cycle period. And

  According to the light control device according to the present invention, the power supply line supplies the lighting device with the minimum power necessary for stable operation during the power supply period, and supplies the lighting device with the light control degree indication period. To indicate the dimming level. As a result, it is not necessary to provide a wiring for transmitting a dimming signal other than the power supply line, so that the cost for wiring work can be reduced and the existing lighting fixture can be changed to a lighting fixture with a dimming function. Since it becomes easy to replace, it is possible to promote the spread of lighting fixtures with a dimming function with high energy saving effect.

1 is a system configuration diagram illustrating an overall configuration of a lighting control system 800 according to Embodiment 1. FIG. FIG. 3 is a circuit configuration diagram illustrating a configuration of the light control device 100 according to the first embodiment. FIG. 3 is a graph showing an example of voltages at various parts of the light control device 100 according to the first embodiment. The conceptual diagram which shows an example of the pattern of the order of the light control degree instruction | indication period and electric power supply period which the light modulation apparatus 100 in Embodiment 1 determines. FIG. 9 shows a modification of the switching circuit 150 in Embodiment 1; FIG. 9 is a graph showing an example of voltages at various parts of the light control device 100 in a modification of the first embodiment. FIG. 3 is a circuit configuration diagram illustrating a configuration of a lighting device 300 according to Embodiment 1. FIG. 3 is a graph showing an example of voltages at various parts of lighting device 300 according to Embodiment 1. FIG. 3 is a graph showing an example of a zero-cross detection voltage v ′ _z output from the zero-cross detection circuit 320 according to the first embodiment. The figure which shows the relationship between the light control degree which the light control degree determination part 342 in Embodiment 1 determines, and the length of the interruption | blocking period t. FIG. 9 shows a modification of lighting device 300 in Embodiment 1. The figure which shows the modification of the relationship between the light control degree which the light control degree determination part 342 in Embodiment 1 determines, and the length of the interruption | blocking period t. FIG. 5 is a circuit configuration diagram illustrating a configuration of a lighting device 300 according to Embodiment 2.

Embodiment 1 FIG.
The first embodiment will be described with reference to FIGS.

FIG. 1 is a system configuration diagram showing an overall configuration of a lighting control system 800 according to this embodiment.
The lighting control system 800 includes a light control device 100 and a plurality of lighting fixtures 200.
The dimmer 100 is inserted in the middle of power lines 811 and 812 that supply AC power from an AC power source AC such as a commercial power source to the lighting apparatus 200. The light control device 100 instructs the lighting fixture 200 through the power lines 811 and 812 to determine the brightness (hereinafter referred to as “light control level”) for turning on the light source LA.
Each of the lighting fixtures 200 includes a lighting device 300 and a light source LA. The lighting device 300 generates power for lighting the light source LA from the AC power input from the power supply lines 811 and 812. The lighting device 300 receives an instruction from the dimming device 100 via the power supply lines 811 and 812, and lights the light source LA with the instructed dimming degree.

FIG. 2 is a circuit configuration diagram showing the configuration of the light control device 100 according to this embodiment.
The dimming device 100 includes a power supply circuit 110, a zero cross detection circuit 120, a dimming degree input circuit 130, a switch control circuit 140, and a switching circuit 150. The dimming device 100 supplies the alternating current power from the AC power source AC to the lighting device 300 by turning on and off the switching circuit 150, and interrupts the supply, thereby instructing the lighting device 300 about the dimming degree. To do.

The power supply circuit 110 includes a transformer T11, a diode bridge DB1, a rectifying element D12, a smoothing capacitor C13, and a power supply IC 114.
The transformer T11 steps down the voltage of the AC power supplied from the AC power supply AC, and the diode bridge DB1 performs full-wave rectification to generate a pulsating voltage and charges the smoothing capacitor C13. The pulsating voltage generated by the diode bridge DB1 is used by the zero-cross detection circuit 120 for detection of the zero-cross, so that the rectifier element D12 blocks the influence of the voltage charged in the smoothing capacitor C13. The power supply IC 114 stabilizes the voltage charged in the smoothing capacitor C <b> 13 and serves as a DC power supply that is supplied to each part in the light control device 100.

The zero-cross detection circuit 120 (zero-cross circuit) detects a timing (hereinafter referred to as “zero-cross”) when the voltage of the AC power supplied from the AC power supply AC becomes almost zero. The zero cross detection circuit 120 includes voltage dividing resistors R21 and R22, a constant voltage diode Z23, a switching element Q24, and a pull-up resistor R25.
When the pulsating voltage generated by the diode bridge DB1 is divided by the voltage dividing resistors R21 and R22 and exceeds the breakdown voltage of the constant voltage diode Z23, the switching element Q24 is turned on, and the voltage drop of the pull-up resistor R25 causes a zero crossing. The voltage at the connection point between the switching element Q24 and the pull-up resistor R25 output from the detection circuit 120 (hereinafter referred to as “zero cross detection voltage v _z ”) is a low potential. Voltage dividing resistors R21, R22 are obtained by dividing the, case of the breakdown voltage below the constant voltage diode Z23, the switching element Q24 is turned off, the zero-cross detection voltage v _z, the voltage of the DC power supply circuit 110 has generated Almost equal. Thereby, the zero cross detection circuit 120 detects the zero cross of the voltage of the AC power supplied from the AC power supply AC.

  The dimming degree input circuit 130 inputs a desired dimming degree specified by the user. The dimming degree input circuit 130 includes a variable resistor VR. The user turns the slider of the variable resistor VR to a position corresponding to a desired dimming degree. The dimming degree input circuit 130 outputs a voltage obtained by dividing the DC voltage generated by the power supply circuit 110 by the variable resistor VR.

The switching circuit 150 includes a photo bidirectional thyristor coupler PC, resistors R52 and R53, and a bidirectional thyristor T54.
The bidirectional thyristor T54 (switching element) is inserted into the power supply line 811 and is turned on for a period from when the trigger current becomes a predetermined value or more until the current flowing through the power supply line 811 becomes zero. The period is turned off. The photo bidirectional thyristor coupler PC is for driving the bidirectional thyristor T54. When the potential of the switch signal output from the switch control circuit 140 becomes low, the primary light emitting diode emits light due to the current flowing through the resistor R52. Then, the secondary photo bidirectional thyristor is turned on, and a trigger current flows through the bidirectional thyristor T54 via the resistor R53.

The switch control circuit 140 generates a switch signal for turning on and off the switching circuit 150 based on the zero cross detected by the zero cross detection circuit 120 and the dimming degree input by the dimming degree input circuit 130.
The switch control circuit 140 uses a half cycle (hereinafter referred to as “half cycle period T”) of AC power supplied from the AC power supply AC as one unit, and a predetermined number of consecutive half cycle periods T as one cycle. The same pattern of switch signals is repeated. For example, if the frequency of the AC power supply AC is 50 Hz, one cycle of AC power is 20 milliseconds, and the half cycle period T is 10 milliseconds. For example, if 20 half cycle periods T are one cycle, the switch control circuit 140 generates a switch signal that repeats the same pattern every 0.2 seconds.
Based on the zero cross detected by the zero cross detection circuit 120, the switch control circuit 140 sets a period from when the voltage of the AC power supplied from the AC power supply AC is zero crossed to the next zero cross to a half cycle period T. . The switch control circuit 140 uses the half cycle period T at a predetermined position among the plurality of half cycle periods T included in one cycle as a dimming degree instruction period, and the other half cycle period T as a power supply period. To do.
The switch control circuit 140 divides the dimming degree instruction period into a conduction period (on period) and a cutoff period (off period) based on the dimming degree input by the dimming degree input circuit 130. The switch control circuit 140 turns on the switching circuit 150 during the conduction period, supplies AC power from the AC power supply AC to the lighting device 300, and turns off the switching circuit 150 during the interruption period. Then, the supply of AC power to the lighting device 300 is cut off. Thus, the lighting device 300 is instructed about the dimming degree.
Further, during the power supply period, the switch control circuit 140 continues to turn on the switching circuit 150 to supply AC power from the AC power supply AC to the lighting device 300. Thereby, the minimum electric power required for stable operation is supplied to the lighting device 300.

The switch control circuit 140 is configured by, for example, a microcomputer, a logic circuit, or the like. The switch control circuit 140 includes a half cycle counting unit 141, a dimming degree instruction period determining unit 142, and a switch signal generating unit 143. When the switch control circuit 140 is configured by a microcomputer, these blocks are realized by the microcomputer executing a program stored in advance.
The half cycle counting unit 141 counts the number of half cycle periods T based on the zero cross detected by the zero cross detection circuit 120. When the number of half cycle periods T counted reaches the number of half cycle periods T included in one period, the half cycle counting unit 141 resets the counted number. As a result, the half cycle period T of the current half cycle period T in one cycle is determined.
The dimming degree instruction period determining unit 142 stores in advance how many half-cycle periods T in one cycle are used as the dimming degree instruction period. When the number of half cycles counted by the half cycle counting unit 141 matches the position of the dimming degree instruction period stored in advance, the dimming degree instruction period determining unit 142 determines the current half cycle period T as the dimming degree instruction period. It is determined that In other cases, the dimming degree instruction period determining unit 142 determines that the current half cycle period T is the power supply period.
Based on the determination result determined by the dimming degree instruction period determination unit 142, the switch signal generation unit 143 generates a switch signal for turning on the switching circuit 150 when the current half cycle period T is the power supply period. The switch signal is represented by the voltage at the output terminal of the switch signal generation unit 143 (hereinafter referred to as “switch signal voltage v _SW ”). In this example, since the switching circuit 150 is turned on when the switch signal voltage v _SW is at a low potential, the switch signal generation unit 143 sets the switch signal voltage v _SW to a low potential.
When the current half-cycle period T is the dimming degree instruction period, the switch signal generation unit 143 turns on the switching circuit 150 during the conduction period based on the dimming degree input by the dimming degree input circuit 130, and A switch signal for turning off is generated. For example, the switch signal generation unit 143 sets the first half of the half cycle period T, which is the dimming degree instruction period, as the cutoff period and the second half as the conduction period, and lengthens the cutoff period in the case of the dimming degree to light the light source LA darkly. In the case of the dimming degree that brightly lights LA, the conduction period is lengthened.

FIG. 3 is a graph showing an example of voltages at various parts of the light control device 100 according to this embodiment.
The voltage (hereinafter referred to as “power supply voltage v _AC ”) that the dimmer 100 inputs from the AC power supply AC is, for example, a sine wave of 50 Hz to 60 Hz and 100 V to 254 V.
Zero-crossing detecting circuit 120 detects a zero crossing of the supply voltage v _AC, and outputs one pulse every half cycle of the power supply voltage v _AC.
The half cycle counting unit 141 counts the pulses of the zero-crossing detection voltage v _z , and the dimming degree indicating period determining unit 142 sets the half cycle period at a predetermined position in one cycle as the dimming degree indicating period, The other half cycle period is defined as a power supply period.
Switching signal generating unit 143, the power supply period, the switch signal voltage v _SW to a low potential, the dimming degree instruction period, every half-cycle period, as a blocking period duration t of the first half, the high switching signal voltage v _SW The switch signal voltage v _{SW is set} to a low potential with the potential set to the remaining period and the remaining period set to the conduction period.
The switching circuit 150, while the switch signal voltage v _SW is low potential, and, during a period from a switch signal voltage v _SW is low potential until the current through the power line 811 becomes 0, conduction, and the other Insulate for a period. Thereby, the voltage output from the dimming device 100 (hereinafter referred to as “power supply voltage with dimming signal v ′ _AC ”) is substantially the same as the power supply voltage v _AC in the power supply period, and in the dimming degree instruction period, A waveform with a part of a sine wave cut out.

FIG. 4 is a conceptual diagram illustrating an example of an order pattern of the dimming degree instruction period and the power supply period determined by the dimming apparatus 100 according to this embodiment.
In the pattern 511, the dimming device 100 supplies 20 half cycle periods T as one period, the first two half cycle periods T as dimming degree instruction periods, and the remaining 18 half cycle periods T as power supply. Period.
In the pattern 512, the dimming device 100 uses the 20 half cycle periods T as one period, the first and third half cycle periods as the dimming degree instruction period, and the second, fourth and subsequent half cycle periods as power. Supply period.
In the pattern 513, the dimming device 100 sets 10 half cycle periods T as one cycle, the first half cycle period as a dimming degree instruction period, and the remaining nine half cycle periods as power supply periods.

For example, in the case of the pattern 511, the half cycle counter unit 141 starts counting from 0, count the number of pulses of the zero cross detection voltage v _z, returns to 0 if turned 20. The dimming degree instruction period determining unit 142 determines that it is the dimming degree instruction period when the number counted by the half cycle counting unit 141 is 0 or 1, and determines that it is the power supply period otherwise. .

  The number of half-cycle periods constituting one cycle, the number of dimming instruction periods, and the order pattern of the dimming instruction periods and the power supply period may be arbitrarily set, but constitute one period The ratio of the number of dimming instruction periods to the number of half cycle periods is most preferably about 10 to 1. Then, in the dimming degree instruction period, the cutoff period t is substantially equal to the half cycle period T, and even when almost no power is supplied to the lighting device 300, the cutoff period t is almost zero. Then, since 90% of electric power can be supplied to the lighting device 300, normal operation of the lighting device 300 can be guaranteed. If the ratio of the dimming degree instruction period is further lowered, the minimum electric power that can be supplied to the lighting device 300 increases, but the time required for the dimming degree instruction to reach the lighting device 300 becomes longer. For this reason, it is preferable that the ratio of the dimming degree instruction period to the half cycle period is in the range of 5: 1 to 20: 1.

FIG. 5 is a diagram showing a modification of the switching circuit 150 in this embodiment.
In this example, the switching circuit 150 includes a switching element Q55 and a diode bridge DB2. Switching element Q55, the switching signal voltage v _SW is turned on when the high potential, the OFF time of the low potential. The switching element Q55 is, for example, a MOS-FET, and is different from the bidirectional thyristor T54 in that current can flow only in one direction. For this reason, the diode bridge DB2 rectifies the current flowing in one direction when the switching element Q55 is turned on.

FIG. 6 is a graph showing an example of voltages at various parts of the light control device 100 according to a modification of this embodiment.
Switching signal generating unit 143, the power supply period, the switch signal voltage v _SW to a high potential, the dimming degree instruction period, every half cycle period T, the period of the first half as a conduction period, the high switching signal voltage v _SW The switch signal voltage v _{SW is set} to a low potential with the second half period t as the cutoff period. As a result, the power supply voltage v ′ _AC with a dimming signal is substantially the same as the power supply voltage v _AC during the power supply period, and has a waveform obtained by cutting out a part of the sine wave during the dimming degree instruction period.

When the bidirectional thyristor T54 is used, once the bidirectional thyristor T54 is turned on, the on state is continued until the current flowing through the power supply line 811 becomes zero. For this reason, the interruption period needs to be set in the first half of the half cycle period. In contrast, in the modified example, if a switch signal voltage v _SW to a low potential, since at any time it is possible to turn off the switching element Q55, the position of the cut-off period is not limited. Therefore, if the cut-off period is set from the middle to the end of the half cycle period, the voltage is not suddenly applied to the lighting device 300 when the switching element Q55 is turned on from the off state. Can be suppressed.

FIG. 7 is a circuit configuration diagram showing the configuration of the lighting device 300 according to this embodiment.
The lighting device 300 is a device that lights a discharge lamp such as a fluorescent lamp as the light source LA. The lighting device 300 includes a diode bridge DB3, a DC power supply circuit 360, an inverter circuit 370, lamp detection resistors R31 and R32, a choke coil L81, a coupling capacitor C82, a starting capacitor C83, a control power supply circuit 310, a zero cross detection circuit 320, and a lamp detection circuit. 330, a drive control circuit 340, and a drive circuit 350.
The diode bridge DB3 receives the dimming signal-added power supply voltage v ′ _AC from the dimming device 100 via the power supply lines 811 and 812, and performs full-wave rectification.
The DC power supply circuit 360 generates a DC voltage from the voltage that is full-wave rectified by the diode bridge DB3. The DC power supply circuit 360 is an active filter circuit (harmonic suppression circuit, boost chopper circuit) including, for example, a PFC 361, a switching element Q62, a resistor R63, a choke coil L64, a rectifying element D65, and a smoothing capacitor C66.
The inverter circuit 370 (power conversion circuit, half-bridge circuit) generates a high-frequency AC voltage from the DC voltage generated by the DC power supply circuit 360. Inverter circuit 370 has two switching elements Q71 and Q72 electrically connected in series to the output of DC power supply circuit 360. Switching elements Q71 and Q72 are turned on and off according to the drive signal generated by drive circuit 350, respectively. When switching elements Q71 and Q72 are alternately turned on and off at high frequency, a high-frequency rectangular wave voltage is generated at the connection point of switching elements Q71 and Q72.
Drive circuit 350 generates a drive signal in accordance with the control signal generated by drive control circuit 340.
The choke coil L81 (ballast choke) limits the current flowing through the light source LA (hereinafter referred to as “lamp current”). The coupling capacitor C82 (DC cut capacitor) cuts the DC component of the AC voltage generated by the inverter circuit 370. The starting capacitor C83 resonates with the choke coil L81 when starting the light source LA, thereby generating a high voltage at both ends of the light source LA and starting discharging.
The lamp detection circuit 330 determines whether or not the light source LA is connected. If the light source LA is connected when the inverter circuit 370 is stopped, the DC voltage output from the DC power supply circuit 360 is applied to the coupling capacitor C82 via the lamp detection resistors R31 and R32, and the coupling capacitor C82 is connected. Is charged to a DC voltage generated by the DC power supply circuit 360. On the other hand, if the light source LA is not connected, the coupling capacitor C82 is not charged. The lamp detection circuit 330 determines whether or not the light source LA is connected by detecting the voltage across the coupling capacitor C82.

The control power supply circuit 310 generates a DC voltage serving as a power supply for operating the drive control circuit 340 and the like from the voltage that is subjected to full-wave rectification by the diode bridge DB3.
The zero-cross detection circuit 320 detects the zero-cross of the power supply voltage v ′ _AC with the dimming signal from the voltage that is full-wave rectified by the diode bridge DB3. The configuration of the zero cross detection circuit 320 may be, for example, the same configuration as the zero cross detection circuit 120 of the dimmer 100 or a different configuration.

The drive control circuit 340 (the dimming degree determination circuit) generates a control signal for controlling the drive circuit 350 based on whether or not the light source LA is connected, the dimming degree instructed from the dimming device 100, and the like. For example, when the lamp detection circuit 330 determines that the light source LA is not connected, the drive control circuit 340 generates a control signal that instructs the drive circuit 350 not to generate a drive signal. If drive circuit 350 does not generate a drive signal according to the instruction by the control signal, switching elements Q71 and Q72 are both turned off, and inverter circuit 370 does not generate an AC voltage.
Further, when the lamp detection circuit 330 determines that the light source LA is connected, the drive control circuit 340 determines the dimming degree instructed by the dimmer 100 based on the zero cross detected by the zero cross detection circuit 320. A control signal that instructs the drive circuit 350 to generate a drive signal having a frequency corresponding to the determined dimming degree is generated. In accordance with the instruction by the control signal, the drive circuit 350 generates a drive signal of the instructed frequency, and the switching elements Q71 and Q72 are alternately turned on / off at that frequency, so that the inverter circuit 370 generates an AC voltage of that frequency. To do. Since the lamp current is limited by the choke coil L81, the lamp current is small when the frequency of the AC voltage generated by the inverter circuit 370 is high, and the lamp current is large when the frequency is low. Thereby, the brightness of the light source LA changes.

The drive control circuit 340 is configured by, for example, a microcomputer or a logic circuit. The drive control circuit 340 includes a dimming degree instruction period determination unit 341, a dimming degree determination unit 342, and a control signal generation unit 343. When the drive control circuit 340 is configured by a microcomputer, these blocks are realized by the microcomputer executing a program stored in advance.
The dimming degree instruction period determining unit 341 determines whether the current half cycle period is a dimming degree instructing period or a power supply period based on the zero cross detected by the zero cross detecting circuit 320.
When the dimming degree instruction period determining unit 341 determines that the current half cycle period is the dimming degree instruction period, the dimming degree determination unit 342 determines that the dimming device 100 is based on the zero cross detected by the zero cross detecting circuit 320. The instructed dimming degree is determined.
Based on the determination result of the lamp detection circuit 330, the control signal generation unit 343 generates a drive signal having a frequency corresponding to the dimming degree determined by the dimming degree determination unit 342 when the light source LA is connected. A control signal for instructing the drive circuit 350 is generated.

FIG. 8 is a graph showing an example of voltages at various parts of the lighting device 300 according to this embodiment.
The power supply voltage v ′ _AC with a dimming signal input from the dimming device 100 via the power supply lines 811 and 812 by the lighting device 300 is a sine wave cut out during the power supply period and a part of the sine wave cut out during the dimming instruction period. It was a waveform.
The voltage output from the zero-cross detection circuit 320 (hereinafter referred to as “zero-cross detection voltage v ′ _z ”) is the same as the zero-cross detection voltage v _z output from the zero-cross detection circuit 120 in the power supply period every half cycle period T. One short pulse. In contrast, in the dimming degree instruction period, during the blocking period t, because the zero-cross detection voltage v _'z becomes high potential, the pulse width is increased. Pulse width of the zero-crossing detection voltage v _'z is substantially the same as the length of the cut-off period t.
The dimming degree determination unit 342 obtains the length of the half cycle period T from the pulse interval in the power supply period, and obtains the length of the cutoff period t from the pulse width in the dimming degree instruction period. The dimming degree determination unit 342 obtains the dimming degree instructed by the dimming device 100 from the obtained length of the half cycle period T and the length of the cutoff period t.

FIG. 9 is a graph showing an example of the zero-cross detection voltage v ′ _z output from the zero-cross detection circuit 320 in this embodiment.
In this figure, the horizontal axis represents time. However, the dimming device 100 turns back every 20 half-cycle periods, which is one cycle, and shows a total of 80 half-cycle periods.

The lighting device 300 stores in advance the number of half-cycle periods T (20 in this example) that the dimmer 100 uses as one cycle, but it is not specified when one cycle starts. It is necessary to judge this. In addition, when an instantaneous power failure (instant blackout) or sag (voltage drop) occurs in the AC power supply AC, it is confusing with the interruption by the light control device 100, and it is necessary to distinguish this.
In this figure, there are some places in which the pulse interval or the width of the zero-crossing detection voltage v _'z is different from normal. Among these, the pulse 521 is due to the blocking by the light control device 100. Pulses 522 and 525 are pulses in which the power supply voltage v ′ _AC with dimming signal is lowered due to the sag of the AC power supply AC and the width of the pulse becomes wider than usual. Pulses 523 and 524 are detected as a zero cross because the power supply voltage v ′ _AC with dimming signal becomes 0 due to the instantaneous power interruption of the AC power supply AC.
As shown in this figure, when turning back every time, which is one cycle, the block by the light control device 100 always appears at the same position, whereas the cause due to other causes varies in the position where it appears. It is. The dimming degree instruction period determination unit 341 uses this to determine the dimming degree instruction period.

The dimming degree instruction period determination unit 341 first obtains the length of the half cycle period T. This is because the length of the half cycle period T varies depending on the frequency of the AC power supply AC. Dimming instruction period determining unit 341 measures the pulse interval of the zero-cross detection voltage v _'z, on average the interval of the measured pulse, determine the length of the half-cycle period T. At this time, the dimming degree instruction period determination unit 341 excludes, as the pulse 523 and the pulse 524, when the interval is significantly larger than the interval of other pulses or when the interval is significantly smaller, as an abnormal value. To calculate an average value.
Next, the dimming degree instruction period determination unit 341 obtains the length of one period based on the number of half-cycle periods T (20 in this example) constituting one period stored in advance.
Then, the dimming degree instruction period determination unit 341 classifies the pulses of the zero-cross detection voltage v ′ _{z according} to the elapsed time from the start time with the half cycle period T as a unit, with an appropriate time as the start time of one cycle. . Thus, the pulse of zero cross detection voltage v _'z are classified into groups of the same number as the number of the half-cycle period T constituting one cycle.
Dimming instruction period determining unit 341, for each group classified, the average value of the pulse width of the zero-crossing detection voltage v _'z. As a result, the influence when the pulse width temporarily increases as in the pulses 522 to 525 is eliminated, and only the variation in the pulse width that always appears at the same position as in the pulse 521 is detected. When the average value of the obtained pulse width is larger than a predetermined value, the dimming degree instruction period determination unit 341 sets the corresponding half cycle period as a candidate for the dimming degree instruction period.
The dimming degree instruction period determination unit 341 stores in advance a pattern of the order in which the dimming apparatus 100 arranges the dimming degree instruction period and the power supply period. The dimming degree instruction period determination unit 341 compares the pattern stored in advance with the obtained dimming degree instruction period candidates to determine which half cycle period T is the dimming degree instruction period.

For example, when the pattern stored in advance by the dimming degree instruction period determination unit 341 is the pattern 511 illustrated in FIG. 4, the dimming degree instruction period is two continuous half-cycle periods T. The dimming degree instruction period determining unit 341 uses the eleventh and twelfth half cycle periods T as candidates for the dimming degree instructing period from the zero cross detection voltage v ′ _z shown in FIG. Since they are continuous, it is determined that these two half cycle periods T are dimming degree instruction periods. If there are three candidates for the dimming degree instruction period, two are continuous, and one is separated, the dimming degree instruction period determining unit 341 includes two consecutive half-cycle periods T among the three candidates. Is determined to be the dimming degree instruction period.

  In this way, for the half cycle period T in which the dimming degree instruction period determining unit 341 determines that it is the dimming degree instructing period, the dimming degree determining unit 342 obtains the length of the cutoff period t and determines the dimming degree. At this time, the dimming degree determination unit 342 sets the average value of the pulse width obtained by the dimming degree instruction period determination unit 341 as the length of the cutoff period t, and the length of the half cycle period T obtained by the dimming degree instruction period determination unit 341. The dimming degree may be determined based on the length of the cut-off period t, or the dimming degree may be determined using the pulse width in the latest half cycle period T as the length of the cut-off period t. May be.

FIG. 10 is a diagram illustrating the relationship between the dimming degree determined by the dimming degree determination unit 342 and the length of the cutoff period t in this embodiment.
If the length of the cut-off period t is _{t 1} or less, the dimming degree determination unit 342 determines that 100% dimming degree. t ₁ is set to a time longer than the length of the period in which the zero cross detection circuit 320 detects the zero cross when the power supply voltage v ′ _AC with the dimming signal is not cut off at all.
When the length of the blocking period t is not less than t _{1 and not} more than t ₂ , the dimming degree determination unit 342 determines the dimming degree so that the dimming degree becomes lower as the blocking period t becomes longer.
If the length of the cut-off period t is t _2, the dimming degree determination unit 342 determines that the dimming degree is the lowest dimming ratio (e.g. 25%).
If the length of the cut-off period t is shorter than the half cycle period T longer than t _2, the dimming degree determination unit 342 determines the dimming degree of 0% (i.e. off). As a result, it is possible to control the turning on / off of the light source LA only by the dimming signal.
Since the length of the half cycle period T changes when the power supply frequency changes, it is preferable to set t ₁ and t ₂ not as absolute time but as a ratio with respect to the half cycle period T.

Thus, the dimming degree determination unit 342, cut-off period t is higher shorter dimming degree, when cut-off period t is shorter than t ₁ is the dimming degree is 100%. Thereby, for example, even when the dimming device 100 fails and the switching circuit 150 is not turned off, the dimming degree becomes 100%, so that the light source LA can be kept on.

FIG. 11 is a diagram showing a modified example of the lighting device 300 in this embodiment.
In this example, the lighting device 300 lights a light source LA that is lit by a direct current such as an LED. The lighting device 300 includes an inverter circuit 370, a choke coil L81, a coupling capacitor C82, a diode bridge DB4, and a smoothing capacitor C84. Note that a circuit preceding the inverter circuit 370, the drive control circuit 340, and the like are omitted.
The high-frequency AC voltage generated by the inverter circuit 370 is applied to a load circuit including the choke coil L81, the coupling capacitor C82, the diode bridge DB4, the smoothing capacitor C84, and the light source LA. The coupling capacitor C82 cuts the DC component of the high-frequency AC voltage generated by the inverter circuit 370. The load current flowing from the inverter circuit 370 is limited by the choke coil L81, the diode bridge DB4 is full-wave rectified, the smoothing capacitor C84 removes high frequency components, and the light source LA is turned on.

  Also in the lighting device 300 having such a configuration, the current flowing through the light source LA can be adjusted by changing the frequency of the AC voltage generated by the inverter circuit 370. The light source LA can be turned on at a desired dimming level by changing the frequency of the drive signal generated by the drive circuit 350 based on the dimming level determined by the dimming level determination unit 342.

FIG. 12 is a diagram illustrating a modified example of the relationship between the light control level determined by the light control level determination unit 342 and the length of the blocking period t in this embodiment.
When using an LED as a light source LA, there is no need to provide a minimum dimming degree, when the length of the cut-off period t is t _2, the dimming degree determination unit 342 determines that the dimming is 0% It is good also as composition to do. Also, t ₂ may be the same as the length of the half-cycle period T.

In the dimming device 100 in this embodiment, the switch control circuit 140 provides the power supply lines 811 and 812 by providing a half cycle period T as a dimming degree instruction period and a half cycle period T as a power supply period. Accordingly, it is possible to instruct the lighting device 300 for the dimming degree during the dimming degree instruction period while supplying the minimum power necessary for stable operation to the lighting device 300 during the power supply period. Thereby, since it is not necessary to provide wiring for transmitting a dimming signal other than the power supply lines 811 and 812, the cost for wiring work can be reduced, and an existing lighting fixture can be equipped with a dimming function. Since it becomes easy to exchange with the lighting fixture 200, the spread of the lighting fixture 200 with a dimming function with a high energy-saving effect can be promoted.
Further, since the switch control circuit 140 has two or more consecutive predetermined number of half-cycle periods T as one period, and the half-cycle period T at a predetermined position in one period is set as the dimming degree instruction period. On the lighting device 300 side, it becomes easy to distinguish between the dimming degree instruction period and the power supply period, and the dimming degree can be instructed to the lighting apparatus 300 with certainty.
Further, since the switch control circuit 140 repeats one cycle a plurality of times, it becomes easier for the lighting device 300 to distinguish between the dimming degree instruction period and the power supply period, which is more reliable for the lighting device 300. The dimming degree can be indicated.

In the lighting device 300 in this embodiment, the inverter circuit 370 (power conversion circuit) converts the AC power supplied from the power supply lines 811 and 812 into power for lighting the light source LA, and the drive control circuit 340 (light control level). Determination circuit) detects the cutoff period t by the dimmer 100 based on the zero crossing of the AC power supplied from the power supply lines 811 and 812, and the dimmer 100 instructs based on the detected cutoff period t Since the dimming degree is determined, it is possible to receive the dimming degree instructed by the dimming device 100 while receiving supply of power necessary for stable operation via the power supply lines 811 and 812. Thereby, since it is not necessary to provide wiring for transmitting a dimming signal other than the power supply lines 811 and 812, the cost for wiring work can be reduced, and an existing lighting fixture can be equipped with a dimming function. Since it becomes easy to exchange with the lighting fixture 200, the spread of the lighting fixture 200 with a dimming function with a high energy-saving effect can be promoted.
Further, the drive control circuit 340 takes two or more consecutive predetermined numbers of half cycle periods T as one period, and the period during which the AC power is cut off in the half cycle period T at a predetermined position in one period. Therefore, it is determined that the cutoff period t is when the light control device 100 is shut off, so that the light control device 100 can clearly distinguish the light shut-off from other factors, and the light control degree indicated by the light control device 100 can be determined. Can be received reliably.
Furthermore, since the drive control circuit 340 determines that the AC power is cut off during the half cycle period T at the same position among the plurality of cycles as the cut-off period t when the dimming device 100 is cut off. The blocking by the device 100 can be more clearly distinguished from the blocking by other factors, and the dimming degree instructed by the dimming device 100 can be received more reliably.

  According to the lighting control system 800 in this embodiment, the power required for operation is supplied to the lighting device 300 via the power supply lines 811 and 812, and the dimming degree of the lighting device 300 from the light control device 100 is adjusted. Instructions can be communicated. Thereby, since it is not necessary to provide wiring for transmitting a dimming signal other than the power supply lines 811 and 812, the cost for wiring work can be reduced, and an existing lighting fixture can be equipped with a dimming function. Since it becomes easy to exchange with the lighting fixture 200, the spread of the lighting fixture 200 with a dimming function with a high energy-saving effect can be promoted.

Embodiment 2. FIG.
Embodiment 2 will be described with reference to FIG.
In addition, about the part which is common in Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

FIG. 13 is a circuit configuration diagram showing the configuration of the lighting device 300 according to this embodiment.
The light source LA lit by the lighting device 300 is a circuit in which a plurality of light emitting diodes are electrically connected in series, for example, and is lit by direct current power. The light source LA is brighter as the applied voltage is higher, and darker as it is lower.
The lighting device 300 includes a diode bridge DB3, a DC power supply circuit 360, a zero-cross detection circuit 320, and a voltage control circuit 340 ′.

The DC power supply circuit 360 receives the power output from the diode bridge DB3 and generates DC power. The DC power generated by the DC power supply circuit 360 is applied to the light source LA and turns on the light source LA. The DC power supply circuit 360 changes the voltage value of the generated DC power according to the control signal generated by the voltage control circuit 340 ′. The DC power supply circuit 360 is, for example, a flyback DC / DC conversion circuit. The DC power supply circuit 360 includes rectifier elements D65, D68, D95, smoothing capacitors C66, C96, a transformer T90, a rectifier element D68, and a constant voltage diode Z69.
The smoothing capacitor C66 smoothes the pulsating voltage that has been full-wave rectified by the diode bridge DB3 to generate a substantially constant DC voltage.
The rectifying element D65 includes a pulsating voltage that is full-wave rectified by the diode bridge DB3 and a DC voltage that is smoothed by the smoothing capacitor C66 so that the zero-crossing detection circuit 320 can detect the zero-crossing from the pulsating voltage that is full-wave rectified by the diode bridge DB3. Isolate.
The switching element Q67 is, for example, a MOSFET. The switching element Q67 opens and closes according to the control signal output from the voltage control circuit 340 ′. When the switching element Q67 is turned on, the voltage across the smoothing capacitor C66 is applied to the primary winding L91 of the transformer T90.
The constant voltage diode Z69 is a Zener diode, for example, and becomes conductive when a voltage of a predetermined level or more is applied in the reverse direction. A series circuit of the constant voltage diode Z69 and the rectifier element D68 is electrically connected in parallel to the primary winding L91, and prevents a voltage exceeding a predetermined value from being generated in the primary winding L91.
The rectifying element D95 limits the current flowing in the secondary winding L92 of the transformer T90 in one direction by opening and closing the switching element Q67.
The smoothing capacitor C96 is charged by the current flowing through the secondary winding L92, and generates a DC voltage applied to the light source LA.

  The switching element Q67 opens and closes at high frequency according to the control signal generated by the voltage control circuit 340 '. If the ratio (on duty) between the length of the period during which switching element Q67 is turned on and the period for opening / closing switching element Q67 is large, the voltage charged in smoothing capacitor C96 increases, and light source LA lights up brightly. On the contrary, if the on-duty is small, the voltage charged in the smoothing capacitor C96 is low, and the light source LA is lit darkly.

The voltage control circuit 340 ′ includes a dimming degree instruction period determination unit 341, a dimming degree determination unit 342, and a control signal generation unit 343.
The control signal generation unit 343 generates a control signal for opening and closing the switching element Q67 based on the dimming degree determined by the dimming degree determination unit 342. The control signal generation unit 343 generates a control signal that increases the on-duty as the dimming degree determined by the dimming degree determination unit 342 is high, and conversely, the control signal generation unit 343 turns on as the dimming degree determined by the dimming degree determination unit 342 decreases. A control signal with a reduced duty is generated.

  In this way, when the light source LA is lit by DC power and the brightness can be changed by the applied voltage, the DC voltage generated by the DC power supply circuit 360 that generates DC power for driving the light source LA is used. The brightness of the light source LA can be changed by changing the voltage control circuit 340 ′ based on the dimming degree determined.

  The voltage control circuit 340 'determines the dimming degree based on the zero cross detected by the zero cross detection circuit 320 based on the pulsating voltage obtained by full-wave rectifying the alternating current input from the diode bridge DB3 from the power supply lines 811 and 812. Therefore, the lighting device 300 can input a dimming degree instruction through the power supply lines 811 and 812, and does not require a separate wiring from the power supply lines 811 and 812. In addition, since the lighting device 300 can receive supply of sufficient power necessary for operation during the power supply period, it can operate normally.

DESCRIPTION OF SYMBOLS 100 Light control apparatus, 110 Power supply circuit, 114 Power supply IC, 120,320 Zero cross detection circuit, 130 Light control input circuit, 140 Switch control circuit, 141 Half cycle counting part, 142 Light control degree instruction | indication period determination part, 143 Switch signal generation part , 150 switching circuit, 200 lighting fixture, 300 lighting device, 310 control power supply circuit, 330 lamp detection circuit, 340 drive control circuit, 340 ′ voltage control circuit, 341 dimming degree indicating period determining unit, 342 dimming degree determining unit, 343 control Signal generation unit, 350 drive circuit, 360 DC power supply circuit, 361 PFC, 370 inverter circuit, 511-513 pattern, 521-525 pulse, 800 lighting control system, 811,812 power line, AC AC power supply, C13, C66, C84 , C96 smoothing capacitor, 82 coupling capacitor, C83 starting capacitor, D12, D65, D68, D95 rectifier, DB1-DB4 diode bridge, L64, L81 choke coil, L91 primary winding, L92 secondary winding, LA light source, PC photo bidirectional thyristor coupler Q24, Q55, Q62, Q67, Q71, Q72 switching element, R21, R22 voltage dividing resistor, R25 pull-up resistor, R31, R32 lamp detection resistor, R52, R53 resistor, T half cycle period, t cutoff period, T11, T90 transformer, T54 bidirectional thyristor, v _AC power supply voltage, v ′ power supply voltage with _AC dimming signal, v _SW switch signal voltage, VR variable resistor, v _z , v ′ _z zero-cross detection voltage, Z23, Z69 constant voltage diode .

Claims (7)

In the dimming device that instructs the dimming degree to the lighting device,
A switching element interposed in a power line for supplying AC power to the lighting device;
A zero cross detection circuit for detecting a zero cross of the voltage of the AC power supplied from the power line;
Based on the zero cross detected by the zero cross detection circuit, a period from when the voltage of the AC power is zero crossed until the next zero cross is defined as a half cycle period, and the switching element is turned on in one half cycle period. A switch control circuit for providing a dimming degree indicating period composed of a combination of a period and a period for insulating the switching element, and a power supply period for conducting the switching element continuously for one half cycle period. A light control device.   The switch control circuit has two or more consecutive predetermined number of half-cycle periods as one period, and among the one period, the half-cycle period at a predetermined position is the dimming degree instruction period, and the dimming degree instruction The light control device according to claim 1, wherein a half cycle period other than the period is the power supply period.   The light control device according to claim 2, wherein the switch control circuit repeats the one cycle a plurality of times. In the lighting device that receives an instruction from the light control device via the power line for inputting AC power, and turns on the light source at the light control level indicated by the light control device,
A zero-cross detection circuit for detecting a zero-cross of the voltage of the AC power supplied from the power line;
Based on the zero-cross detected by the zero-cross detection circuit, the light control device detects a cut-off period in which the dimming device cuts off AC power supplied from the power supply line, and the light control device instructs the control based on the detected cut-off period. A dimming degree determination circuit for determining the dimming degree;
And a power conversion circuit that converts AC power supplied from the power line into power for lighting the light source at the dimming level based on the dimming level determined by the dimming level determining circuit. apparatus.   Based on the zero cross detected by the zero cross detection circuit, the dimming degree determination circuit is configured to perform the zero crossing after the AC power voltage is zero crossed when the AC power supplied from the power supply line is not interrupted. The period is a half cycle period, a predetermined number of two or more consecutive half cycle periods is one period, and the AC power is cut off in the half cycle period at a predetermined position in the one period. The lighting device according to claim 4, wherein the lighting device is determined to be a cut-off period in which the light control device is cut off.   Based on the zero cross detected by the zero cross detection circuit, the dimming degree determination circuit is configured to perform the zero crossing after the AC power voltage is zero crossed when the AC power supplied from the power supply line is not interrupted. When the AC power is cut off in a half cycle period at the same position among a plurality of periods, the half cycle period is a half cycle period, and a predetermined number of two or more consecutive half cycle periods is one period. The lighting device according to claim 4, wherein the lighting device is determined to be a cutoff period in which the light control device is shut off.   An illumination control system comprising: the light control device according to any one of claims 1 to 3; and the lighting device according to any one of claims 4 to 6.

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