JP2012038679A - Illumination control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination control device which is capable of avoiding the occurrence of flickers even when an incandescent lamp and an LED bulb are used to perform dimmed lighting at a predetermined dimming level by stepwise dimming.SOLUTION: An illumination control device 1 according to the present invention includes: a lighting load 2 connected to a commercial power supply AC; a load driving circuit 4 for driving the lighting load 2; a stepwise dimming circuit 7 which transmits a control signal for performing stepwise dimming of the lighting load 2 by phase control, to the load driving circuit 4; and adjusting operation means 6 which is provided in the stepwise dimming circuit 7 and finely adjusts an phase control amount of the phase control.

Description

  Embodiments described herein relate generally to an illumination control device that performs step dimming of a dimming level of an illumination load.

  2. Description of the Related Art Conventionally, there is known an illumination control device that performs step dimming at a preset dimming level by changing the power supplied to a lighting load by phase controlling an AC power supply in a stepwise range from 100% to 0%. Yes.

  For example, an incandescent bulb mounted on a downlight installed in a corridor in a room is turned on / off by operating the switch. During normal hours, all light is turned on (100% on) by operating the switch. Lighting control that dimmes and dims the brightness during a specific set time period (for example, at midnight), and prevents drowsiness from waking up due to the glare of lighting when going to a toilet etc. at midnight Devices (lighting switches) are known. This illumination control device performs dimming lighting at a dimming level set in advance by step dimming during a specific set time period.

  By the way, recently, from the viewpoint of long life and energy saving, LED bulbs using LEDs as light sources have been developed. This LED bulb can be used by being attached to a lighting device such as a downlight through a base, like an incandescent bulb.

Panasonic Electric Works Switch / Outlet Product List Slightly lit switch [Searched on July 20, 2010] (http://denko.panasonic.biz/Ebox/switch/switch26.html)

  However, since the lighting control device as described above is designed assuming an incandescent bulb as an illumination load, the LED bulb is mounted on a lighting fixture and dimmed at a preset dimming level by step dimming. If performed, flicker may occur even with a dimmable LED bulb. Since this is not a design specification assuming an LED bulb, it is considered that the control device causes an abnormal operation due to the load of the LED bulb being smaller than that of the incandescent bulb. The same applies to a bulb-type fluorescent lamp that has a smaller load than an incandescent bulb.

  The present invention has been made in view of the above problems, and illumination control capable of avoiding flicker even when dimming lighting is performed at a dimming level set in advance by step dimming using an incandescent bulb and an LED bulb. An object is to provide an apparatus.

  An illumination control apparatus according to an embodiment of the present invention includes an illumination load connected to a commercial AC power supply, a load drive circuit that drives the illumination load, and step-dimming the illumination load by phase control in the load drive circuit A stage dimming circuit for transmitting a control signal. The stage dimming circuit is provided with an adjusting operation means for finely adjusting the phase control amount of the phase control.

  According to an embodiment of the present invention, there is provided an illumination control device capable of avoiding flicker even when dimming lighting is performed at a dimming level set in advance by step dimming using an incandescent bulb and an LED bulb. It becomes possible.

It is a schematic block diagram which shows the illumination control apparatus which concerns on embodiment of this invention. It is a block block diagram which shows the same illumination control apparatus. It is explanatory drawing which shows the state of the light control level of the illumination load in the illumination control apparatus. It is a table | surface which shows the operation state of the illumination load in the same illumination control apparatus. It is a circuit diagram which shows the same illumination control apparatus. It is a wave form diagram which shows the electric current of the power supply in the same illumination control apparatus, the all-light lighting state of a lighting load, and the light control lighting state.

  Hereinafter, an illumination control device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 6. In addition, the same code | symbol is attached | subjected to the same part in each figure, and the overlapping description is abbreviate | omitted.

  FIG. 1 shows a configuration diagram of a lighting control device. In FIG. 1, the lighting control device 1 includes a lighting load 2 connected to a commercial AC power source AC and a control device 3 connected to the commercial AC power source AC and disposed in the wiring box B.

  The illumination load 2 is an LED bulb mounted on a downlight installed on the ceiling surface. This LED bulb has an E-type base, and includes a plurality of LEDs mounted on a substrate and a lighting circuit that controls lighting of the LEDs in the main body. Therefore, this LED bulb is mounted on the socket of the downlight and is turned on by being fed from the commercial AC power supply AC, and illuminates a predetermined range in the floor direction.

  The wiring box B is a wall-embedded type that is embedded and attached to a wall surface, and an illuminance sensor S1, a human sensor S2, and an adjusting operation means 6 that will be described in detail later are provided on the front side. In addition, an operation time setting switch and the like are provided. The illuminance sensor S1 detects ambient brightness, and the human sensor S2 detects the presence or absence of a human body.

  Next, FIG. 2 shows a block configuration diagram of the illumination control device 1. As shown in FIG. 2, the lighting control device 1 includes a lighting load 2 connected to a commercial AC power supply AC and a control device 3 connected to the lighting load 2. The control device 3 includes a load driving circuit 4, a self-holding circuit 5, a stage dimming circuit 7 having an adjustment operation means 6, an illuminance detection circuit 8, a human body detection circuit 9, and a power supply circuit 10.

  The load drive circuit 4 has a function of supplying power to the lighting load 2 by a switching element or the like. The self-holding circuit 5 has a function of holding the conduction state for a half period of commercial alternating current once the switching element of the load driving circuit 4 is once turned on.

  The stage dimming circuit 7 includes a phase control circuit, and sends a control signal to the load drive circuit 4 so that the current flowing through the load drive circuit 4 becomes a preset phase control amount. That is, it has a function of performing step dimming by setting the phase angle of the alternating current flowing through the illumination load 2 to be constant and, for example, dimming lighting with a dimming level of 60%.

  The adjustment operation means 6 is a rotary adjustment knob and is a means for finely adjusting a preset phase control amount, that is, a phase angle. When performing dimming lighting at a preset dimming level by step dimming using an LED bulb, flickering may occur as described above, but at this time, the phase angle is adjusted by operating the adjustment knob. The occurrence of flicker can be avoided by fine adjustment, specifically, by slightly shifting the phase angle by advancing or delaying it.

  The illuminance detection circuit 8 includes an illuminance sensor S1, measures the ambient brightness, and outputs a detection signal. The illuminance detection circuit 8 controls the load driving circuit 4 based on the detection signal to turn on / off the illumination load 2. Do. Therefore, when the surroundings are bright and the illuminance is high, the illumination load 2 is turned off. On the other hand, when the surroundings are darker than the predetermined illuminance, the illumination load 2 is in the state of all light lighting (light control level 100%) or light control lighting (light control level 60%).

  The human body detection circuit 9 has a human sensor S2 and is a circuit that detects the presence of a human body by detecting infrared rays from the human body. A pyroelectric element as the human sensor S2, an amplifier circuit, and a comparison circuit are provided. When infrared rays emitted from the human body are condensed on the pyroelectric element by a condenser lens or the like, a detection signal is output from the pyroelectric element. This output is amplified by the amplifier circuit, the signal level is compared with a predetermined reference level by the comparison circuit, and the comparison result is output as a human body detection signal. Therefore, when the detection signal of the human body is output, the illumination load 2 is turned on with all-light lighting (dimming level 100%) when the surroundings are dark.

When the surroundings are dark and no human body detection signal is output, the step dimmer circuit 7 causes the lighting load 2 to be stepped so that the dimming level is 60%. It comes to be lit.
The power supply circuit 10 is a circuit that ensures a specified voltage in the control device 3.

  The lighting control device 1 configured in this way performs an operation as shown in FIG. FIG. 3 shows the dimming level of the illumination load 2 in a predetermined state (T1 to T4). The state of T1 is when the illuminance detection circuit 8 determines that the surrounding is bright. In this case, the illumination load 2 is controlled to be turned off. The state of T2 is when the surroundings are determined to be dark by the illuminance detection circuit 8, and when the human body detection circuit 9 does not output a human body detection signal (non-detection). In this case, the illumination load 2 is controlled by step dimming so that the dimming level is 60%.

  The state of T3 is a case where the illuminance detection circuit 8 determines that the surroundings are dark, and the human body detection circuit 9 outputs a human body detection signal. In this case, the lighting load 2 is controlled to be turned on by all-light lighting (light control level 100%). The state of T4 is a case where the state again returns to the same state as the state of T2, the human body detection circuit 9 stops outputting the human body detection signal, and the illuminance detection circuit 8 determines that the surroundings are dark. In this case, the illumination load 2 is again controlled by step dimming so that the dimming level is 60%.

  Such operation states are summarized as shown in FIG. That is, when the surroundings are bright, the illumination load 2 is always turned off. Further, when the surrounding is dark and a human body is detected, all light is turned on (light control level 100%). When the human body is not detected, the light control level is 60%. The dimming light is turned on.

  Here, as shown in FIG. 3, when the lighting load 2 is dimmed by dimming lighting with a dimming level of 60%, that is, the lighting load 2 may flicker. In this case, flickering can be avoided by operating the adjustment knob as the adjustment operation means 6 to finely adjust the phase control amount, that is, the phase angle, and slightly shift it.

  Therefore, even when an incandescent bulb and an LED bulb are used as the illumination load 2 and dimming lighting is performed at a dimming level set in advance by step dimming, it is possible to avoid occurrence of flicker.

  Next, a detailed circuit configuration of the illumination control device 1 having the above configuration will be described with reference to FIG. As shown in FIG. 5, a lighting load 2 is connected to a commercial AC power supply AC, and a control device 3 is connected to this two-wire connection circuit via a full-wave rectifier REC.

  The load driving circuit 4 includes a field effect transistor (MOS FET) Q1 as a switching element connected between both ends of the AC power supply AC, and an inverter circuit (inverse conversion circuit) U1 connected to the gate terminal. . The self-holding circuit 5 includes an NPN transistor Q2 having a collector connected to the source terminal of the field effect transistor Q1, and a transistor Q11 that forms a current mirror circuit with the transistor Q2.

  The stage dimming circuit 7 includes a time constant circuit composed of a series circuit of a variable resistor Rt and a capacitor Ct connected between both ends of the AC power supply AC, a diac DIAC having one end connected between these connections, and the diac DIAC. And the transistor Q16 having the other end connected to the base constitutes a phase control circuit. The variable resistor Rt is provided with adjustment operation means 6. By operating the adjusting operation means 6, the phase value of the variable resistance Rt can be adjusted to finely adjust the phase control amount, that is, the time constant, and the phase angle of the current flowing through the illumination load 2 can be finely adjusted.

  The illuminance detection circuit 8 includes a photodiode FD which is a photoelectric conversion element, and a transistor Q15 having a base connected to an intermediate point between a resistor connected in series to the photodiode FD. The collector of the transistor Q15 is connected to the load drive circuit 4.

  The human body detection circuit 9 includes a human detection module U2 in which a pyroelectric element, an amplification circuit, and a comparison circuit are incorporated, a diode D11 connected to the output side of the human detection module U2, and an anode side of the diode D11 And a transistor Q12 having a base connected thereto. Further, the human detection module U2 is driven by being supplied with the power supply VDD.

The power supply circuit 10 includes a constant voltage diode D2 connected across the AC power supply AC, a transistor Q3 having a base connected to the anode side of the diode D2, and a transistor Q4 having a base connected to the collector side of the transistor Q3. I have. Further, a PNP transistor Q5 is connected to the collector side of the transistor Q4 and connected to a line on one end side of the power supply AC, and a capacitor C1 is connected between both ends of the power supply AC via a diode D3.
The operation of the illumination control apparatus 1 having such a circuit configuration will be described with reference to FIGS.

  (Self-holding circuit) When a load current flows through the field effect transistor Q1, the transistor Q2 is ON, and the current mirror circuit causes the same current as the current flowing through the transistor Q2 to flow through the transistor Q11. Therefore, the input of the inverter circuit U1 is held at “L”, the output is “H”, and the ON state of the field effect transistor Q1 is held.

  Since the input of the inverter circuit U1 is wired or connected by the transistors Q11 and Q12, it is held at “L” regardless of ON / OFF of the transistor Q12 and the output becomes “H”.

  The transistor Q12 controls the ON timing of the field effect transistor Q1. Therefore, once the ON signal is input from the signal system of the transistor Q12, the transistor Q12 is turned ON, the input of the inverter circuit U1 is “L”, the output is “H”, and the field effect transistor Q1 is turned ON. Until the current of the field effect transistor Q1 becomes zero, the field effect transistor Q1 is kept ON during the period (half cycle of the commercial AC power supply).

  (Illuminance detection circuit) When the surroundings are bright, the photodiode FD receives light and is turned on, and the transistor Q15 is turned on. Therefore, the gate terminal of the field effect transistor Q1 becomes “L”, the field effect transistor Q1 is always in the OFF state, and no current flows through the lighting load 2 so that the lighting state is turned off.

  When the surroundings are dark, the photodiode FD is turned off and the transistor Q15 is turned off. Therefore, a signal according to the output signal of the inverter circuit U1 is input to the gate terminal of the field effect transistor Q1.

  (Human Body Detection Circuit) The human detection module U2 is driven by the power supply VDD. When a human body is detected, a detection signal “H” is output to the output OUT. Therefore, when the human body is not detected (non-detection), the output OUT is “L”.

  The switching operation of the diode D11 is turned off when a human body is detected, and turned on when a human body is not detected (in the case of non-detection). Therefore, when a human body is detected, the diode D11 is turned off, the transistor Q12 is turned on, the input of the inverter circuit U1 is “L”, the output is “H”, and the field effect transistor Q1 is turned on. When the human body is not detected (in the case of non-detection), the diode D11 is ON, the transistor Q12 is OFF, the input of the inverter circuit U1 is “H”, the output is “L”, and the field effect transistor Q1 is OFF. It becomes.

  (Power supply circuit) The voltage required for the control device 3 as an internal power supply is 13V. It is the constant voltage diode D2 that determines this voltage. When the AC power supply AC is equal to or lower than the breakover voltage (13V) of the constant voltage diode D2, the transistor Q3 is OFF, the transistors Q4 and Q5 are ON, the AC power supply AC (100V) is applied to the capacitor C1, and the capacitor C1 is charged to 13V. Is done. When the voltage exceeds the breakover voltage (13V) of the constant voltage diode D2, the states of the transistor Q3, the transistor Q4, and the transistor Q5 are inverted, and the power supply to the capacitor C1 is cut off.

  Thus, the power supply of the control device 3 can be secured without affecting the illumination load 2 by using a slight voltage at the initial phase angle of the AC power supply AC (100 V) (see FIG. 6A). ).

  (All-light lighting state) When the AC power supply AC (100V) exceeds the instantaneous value of the breakover voltage (13V) of the constant voltage diode D2 that determines the voltage required as the internal power supply, the constant voltage diode D2 is turned on and the transistor Q12 is driven to turn on, the input of the inverter circuit U1 is “L”, the output is “H”, and the field effect transistor Q1 is turned on. As a result, the AC power AC is supplied to the illumination load 2. The phase angle at which the instantaneous value of the AC power supply AC (100 V) exceeds 13 V is 10 degrees or less, so that the almost full-angle conduction state is established, and the illumination load 2 is in the all-light lighting state (see FIG. 6B).

  The condition for turning on the all-lights is satisfied when the diode D11 is OFF (when a human body is detected) and the transistor Q15 is OFF (when the surroundings are dark).

  (Dimming lighting state) In the time constant circuit composed of the variable resistor Rt and the capacitor Ct, when the voltage across the capacitor Ct exceeds the breakover voltage of the diac DIAC, the diac DIAC is turned on at this timing, and the transistor Q16 is turned on momentarily. The input of the inverter circuit U1 is “L”, the output is “H”, and the field effect transistor Q1 is turned on. Thereafter, the self-holding circuit 5 is operated, and the lighting load 2 is supplied with the phase-controlled current set to be constant by the time constant circuit, so that the lighting load 2 is in a dimming lighting state (FIG. 6 ( c)). Here, when a problem such as flickering of the illumination load 2 occurs, the adjustment control means 6 is operated to adjust the resistance value of the variable resistor Rt to finely adjust the phase control amount, that is, the phase angle (FIG. 6). (C) Indicated by an arrow) to solve the problem.

  The reason for this cancellation is difficult to explain in theory, but the relationship between the phase at the start of phase control conduction in a half cycle of a commercial AC power supply and the transient vibration due to line impedance, etc. It is presumed that there is a conduction start phase where no flickering occurs due to the relationship between and the load current. Actually, the flicker could be eliminated by adjusting the dimming rate within a range of ± several%.

  This dimming lighting condition is satisfied when the diode D11 is ON (when no human body is detected) and the transistor Q15 is OFF (when the surroundings are dark).

  In addition, this invention is not limited to the structure of the said embodiment, A various deformation | transformation is possible in the range which does not deviate from the summary of invention. For example, the present invention can be applied to a case where dimming is performed by dimming at a dimming level set in advance by step dimming in a specific set time zone. Further, the present invention can also be applied to a case where step dimming is performed in a plurality of steps according to ambient brightness.

DESCRIPTION OF SYMBOLS 1 ... Lighting control apparatus, 2 ... Lighting load, 3 ... Control circuit,
4 ... load drive circuit, 5 ... self-holding circuit, 6 ... adjustment operation means,
7 ... Step light control circuit, 8 ... Illuminance detection circuit, 9 ... Human body detection circuit,
10 ... Power supply circuit

Claims (1)

A lighting load connected to a commercial AC power source;
A load driving circuit for driving the lighting load;
A step dimming circuit for sending a control signal for step dimming the illumination load by phase control to the load driving circuit;
Adjusting operation means for finely adjusting the phase control amount of the phase control provided in the stage dimming circuit;
An illumination control device comprising:

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