JP3120138B2 - Dimming control method, dimming control device, and automatic dimming control device - Google Patents

Abstract

PURPOSE: To lessen the light dimming coefficient difference depending on frequency even if the light dimming coefficient is small by controlling the brightness by sending out a triger signal after a prescribed time corresponding to a prescribed light dimming level while the center of a semicycle of an a.c. electric power source being used as a standard. CONSTITUTION: A zero-cross point of an a.c. electric power source is detected by a cycle signal generating means 2. During a synchronous signal which exceeds the point, a clock signal with high frequency is counted by a first counter 31 and a clock signal with a half of the frequency of the former is counted by a second counter 32. A computing circuit 4 adds a value corresponding to a previously set light modulation level to the counted value of the counter 32 and stored in a memory means 5. Comparison of the computed result of the semicycle stored immediate before with the counted value of the counter 31 is carried out by a comparator 6 and a triger signal is sent to a Triac TRC from a triger output circuit 7. Voltage supplied to an incandescent lamp LP can be controlled by that phase control and the light dimming degree at 50Hz and 60Hz electric power frequency thus becomes low and an apparatus can be economical.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dimming control method for controlling the brightness of a lighting fixture using AC power supplies having different frequencies, and a dimming control device using the method.

2. Description of the Related Art Against the background of an aging society and a growing interest in energy saving and a demand for improvement in living comfort and safety, an automatic sensor for detecting the human body by a sensor and controlling the brightness of a lighting fixture. Many dimming control devices have been developed and put into practical use.

[0002] These dimming control devices are used for entrances in houses,
In addition to simply turning on and off lighting equipment such as corridors and stairs based on the detection results of sensors, it is also possible to control the brightness of the lighting equipment, and to meet the above requirements for comfort, safety, etc. and energy savings. Used as a value-added lighting control device.

FIG. 7 shows a configuration of a conventional dimming control device used in such an automatic dimming control device. The dimming control device 1b includes a diode bridge DB, a synchronizing signal generating means 2 for detecting a zero cross point, a control means 2a, a counting clock generating means 3a, a counting means 3, a trigger output means 7, and a bidirectional three-terminal thyristor TRC. , Consisting of
Connected to lighting load LP and AC power supply AG.

[0004] The illumination load LP is an incandescent lamp or the like that is turned on by an AC power supply. The phase of the illumination load LP is controlled by a bidirectional three-terminal thyristor TRC such as a triac, so that dimming control is performed to obtain a desired brightness. The phase control of the thyristor TRC is performed by a trigger signal supplied from the trigger output means 7 to a control terminal of the thyristor TRC. The trigger signal is output from the trigger output means 7 to control the phase of the thyristor TRC because the count clock generation means 3a
This is the point in time when the counting means 3 has counted the clock signal from the counter by the preset count value. The counting operation of the counting means 3 is performed by the control means 2a in response to the zero-cross point detection signal from the synchronization signal generating means 2.

That is, the counting means 3 counts the clock signal from the counting clock generating means 3a by a predetermined count value at each zero-cross point of the output from the AC power supply, and the trigger output means 7 turns on the thyristor TRC. Generate a trigger signal. Accordingly, if the predetermined count value counted by the counting means 3 is set large, the phase angle of the AC power supply when the thyristor starts conducting becomes large, the power supplied to the lighting load LP becomes small, and the lighting load LP becomes small. The illumination of LP becomes dark. On the other hand, if the predetermined count value counted by the counting means 3 is set small, the phase angle of the AC power supply when the thyristor TRC starts conducting becomes small, and the lighting load LP
Of the lighting load LP becomes brighter.

FIG. 8 shows a configuration of a conventional automatic light control device using such a light control device. This automatic light control device 80 includes a Fresnel lens FL, a pyroelectric element 81, a first
Amplifier circuit 82, second amplifier circuit 83, comparison circuit 8
4 and the dimming control circuit 85, and the lighting load LP
And AC power supply AG.

[0007] The Fresnel lens FL converges far-infrared rays radiated from the human body M or the like existing in the detection area SA to the pyroelectric element 81. The pyroelectric element 81 receives far-infrared rays radiated from the floor or the like when no human body is present, but also receives far-infrared rays of the human body M when a person enters the detection area SA. The change is output as a voltage change. Each of the first and second amplifier circuits 82 and 83 includes an amplifier circuit and a band-pass filter. In such a human body detection device, the amplifier circuits 82 and 83 usually include
Since it is necessary to obtain a large gain, such a two-stage configuration is adopted. The amplifier circuit amplifies the output voltage of the pyroelectric element 81, and the band-pass filter peaks around 1 Hz so as to maximize the sensitivity of the walking speed of the normal human body M, and removes the low and high frequency bands. . The comparison circuit 84
The output waveform of the amplifier circuit 83 is compared by a window comparator having upper and lower threshold values, and a comparison result is output. The dimming control circuit 85 is a phase control device for lighting or dimming the illumination load LP for a certain period based on the output of the comparison result, and is configured by the dimming control device 1b.

However, since the commercial AC power supply has two frequencies of 50 Hz and 60 Hz, when such a conventional dimming control device is used,
The dimming rate will differ depending on the area where it is used. Here, the dimming rate is a quantity representing the brightness of the lighting load, and is a value representing the brightness when the brightness of the light emitted from the lighting load when the phase control is not performed is set to 100.

FIG. 9 shows waveforms of which the phases are controlled for the cases of 50 Hz and 60 Hz. (A) in the figure is 50 Hz,
(B) shows the half cycle of the 60 Hz AC wave with the zero-cross point as the origin, and the time from the zero-cross point determined by the predetermined count value counted by the counting means 3 to the output of the trigger signal is 50 Hz. , 60H in the case of 5 mS.

In the case of a 50 Hz AC wave, a trigger signal is output when the phase angle is 90 degrees, and the thyristor TR
C is conductive, but in the case of a 60 Hz AC wave, a trigger signal is generated at a phase angle of about 108 degrees,
The thyristor TRC becomes conductive, and the voltage in the hatched portions in the figure is applied to the lighting loads.

In order to quantitatively determine the difference in the dimming rate in this case, FIG. 10 illustrates the relationship between the phase angle and the effective voltage value during phase control, and FIG. 11 illustrates the effective voltage value and the effective voltage value for an incandescent lamp. The relationship of the dimming rate is illustrated. FIG. 10 shows the relationship between the phase angle and the effective voltage value when phase control is performed using a 100 V commercial AC power supply, in which the horizontal axis represents the phase angle when a trigger signal is generated and the vertical axis represents the effective voltage value at that time. FIG. FIG. 11 is a diagram showing the relationship between the effective voltage value and the dimming rate when the phase of the incandescent lamp is controlled, with the horizontal axis representing the voltage effective value and the vertical axis representing the dimming rate.

Using these relationships, the dimming rates in the case of FIG. 9 are obtained.
Since it is 0 degrees, the effective voltage is about 70 V and the dimming rate is about 30%. In the case of 60 Hz, the phase angle is about 108 degrees, so the effective voltage is about 57 V and the dimming rate is about 1
5%. Accordingly, when the same dimming control device is used, the dimming rate at 50 Hz is about 30%, while the dimming rate at 60 Hz is about 15%, and the dimming rate is about 60%. A large difference of about 15% occurs in light efficiency.

On the other hand, a conventional automatic dimming control device usually has
It has a day or night discrimination function, and does not turn on the light even if a human body is detected in the daytime, but at night, entrances, hallways and stairs in the house from the viewpoint of safety and convenience. Lighting fixtures such as those that are dimly lit and have a dimming rate of 100% when a human body is detected are becoming widespread. Here, in the case of an incandescent lamp or the like, the dimming rate is 60 to 70%.
Above, there is almost no difference in brightness perceived by human eyes. Therefore, in the case of this type of automatic dimming control device, the dimming rate at the time of dim lighting can obtain a sufficient energy saving effect as compared with the case where the lighting is continued at the dimming rate of 100%, and can illuminate the surroundings as a lighting fixture. In order to secure the minimum possible illuminance, about 20 to 25% is adopted. However, in the automatic dimming control device using the conventional dimming control device, as described above, there is a problem that the difference in dimming ratio depending on the power supply frequency increases when the dimming ratio decreases.

In order to solve such a problem, there is a conventional dimming control device that detects the frequency of an AC power supply using a microcomputer. Since the frequency of the basic clock of the microcomputer is sufficiently higher than that of the commercial AC power supply, 50 Hz and 60 Hz are obtained by counting the number of basic clocks included in a half cycle of the AC power supply.
Hz can be distinguished. Therefore, by automatically correcting the time from the zero-cross point to the generation of the trigger signal in accordance with the frequency of the AC power supply, the same dimming rate can be obtained regardless of the frequency of the power supply. However,
There is a problem that the use of the microcomputer makes the dimming control device expensive, and the automatic dimming control device including such a dimming control device also becomes expensive.

The present invention has been made in view of the above circumstances, and has been made aware of the fact that, even with a small dimming rate, the difference between the 50-Hz and 60-Hz AC power supplies does not pose a problem in practice because the difference is small. We proposed a dimming control method for supplying AC power to lighting lamps in a simple way without discriminating the power frequency itself, and a device using the dimming control method. It is intended to be.

[0015]

Means for Solving the Problems The present invention according to claim 1
The light dimming control method is to control the output of the AC power
In a dimming control method for controlling the brightness of a light load,
The half cycle of the AC power supplied to the load is
Counted in advance by the lock signal, and
Value, and further set in advance according to the target dimming rate.
The value to which the correction value has been added is calculated as the firing angle, and the
The AC power supplied to the load
While counting by the signal, the AC power supply
Generates a trigger signal each time the phase control element is turned on.
Control the brightness of the lighting load.
It is a sign.

According to a second aspect of the present invention, in the dimming control device for controlling the brightness of an illumination load by controlling the phase of the output of the AC power supply, a first counter for counting a half cycle of the AC power supply by a clock signal of a predetermined frequency. Storage means for storing, as firing angle data, a value obtained by adding a correction value preset in accordance with a target dimming rate to a value of １ ／ of the count value of the first counter; Comparing means for comparing the count value of the first counter with the firing angle data stored in the storage means, wherein the comparing means matches the count value of the first counter with the firing angle data There has been proposed a dimming control device that generates a trigger signal each time it is determined that the phase control element is conductive.

According to a third aspect of the present invention, in the dimming control device for controlling the brightness of the illumination load by controlling the phase of the output of the AC power supply, a first counter for counting a half cycle of the AC power supply by a clock signal of a predetermined frequency. A second counter that counts a half cycle of the AC power supply by using a clock signal having a frequency half of the clock signal of the first counter; and a first counter and a second counter that count the half cycle of the AC power supply. After counting the clock signal, a value obtained by adding a correction value set in advance according to a target dimming rate to a value obtained by counting the second count value by the first counter is stored as firing angle data. Storage means, and comparison means for comparing the count value of the first counter with the firing angle data stored in the storage means, wherein the comparison means calculates the count value of the first counter. Yo By generating a trigger signal each time it is determined that matches the firing angle data, the dimming control device for conducting a phase control device has been proposed.

According to a fourth aspect of the present invention, there is provided a detecting means capable of detecting a human body in the detecting area, and the dimming control device according to the second or third aspect. There has been proposed a dimming control device that automatically controls dimming by controlling the phase.

According to the dimming control method of the present invention, a half cycle of the AC power supply is counted by the clock signal without discriminating the frequency of the AC power supply, and a half of the counted value is set at the center of the half cycle. By simply defining a value obtained by adding a correction value set in advance in accordance with the target dimming rate to the value as the firing angle, the phase control element can be used for AC power supplies having different frequencies. The brightness of the lighting load can be controlled by conducting.

According to the dimming control device according to the present invention, the frequencies differ by a simple circuit configuration in which the counter circuit, the comparing means, and the storing means for storing the firing angle data are combined. For the AC power supply, the center of the half cycle of the AC power supply is automatically detected, and based on that,
Any dimming rate can be controlled.

According to the automatic dimming control device according to the present invention, the detecting means detects a human body in the detecting area, and the center of the half cycle is determined based on the detection result of the detecting means. In response to a preset dimming level, a trigger signal is output after a predetermined period of time has elapsed, and the phase control element is turned on by the trigger signal of the trigger generating means to reduce the brightness of the illumination load. Control and automatic dimming control.

FIG. 1 shows the configuration of an embodiment of a dimming control device according to the present invention. This dimming control device 1
Is a synchronizing signal generating means 2, a trigger generating means TG comprising a first counter 31, a second counter 32, an arithmetic circuit 4, a storage means 5, a comparator 6, and a trigger output circuit 7, a triac TRC, Diode bridge D
B and connected to the incandescent lamp LP and the AC power supply AG.

The synchronizing signal generating means 2 detects a zero cross point of the AC power supply. In the case of this embodiment, “0” is output when the power supply voltage full-wave rectified by the diode bridge DB is equal to or lower than a certain threshold value near the ground level, and “1” is output when the power supply voltage exceeds this threshold value. Therefore, the pulses from immediately after the zero-cross point to immediately before the next zero-cross point are output from the synchronization signal generating means every half cycle.

The synchronizing signal of the synchronizing signal generation means 2 is "
During the period of “1”, the first counter 31 counts a clock signal having a constant frequency, and the second counter 32 counts a clock signal having a half frequency of the clock signal of the first counter 31. Here, the first and second counters 3
The frequency of the clock signal counted by 1 and 32 is sufficiently higher than the frequency of the AC power supply.

The arithmetic circuit 4 outputs the result of counting the half cycle of the second counter 32, that is, the synchronizing signal of the synchronizing signal generating means 2 as "1".
After a change from “0” to “1”, a predetermined value A is added to the counting result of counting the clock signal of the half frequency during a period from a change to “1” to “0”. The value A is a value corresponding to a preset dimming level, and when 0, the dimming rate is 100%.

The storage means 5 is a storage means for storing the operation result of the operation circuit. The storage means 5 is constituted by a register or the like, and holds, as a firing angle data, a calculation result obtained from the counting result of the immediately preceding half cycle during a half cycle.

The comparator 6 is provided with the first counter 3
The count value of 1 is compared with the value of the storage means 5 to detect whether or not these values match.

The trigger output circuit 7 is provided with the comparator 6
And outputs a trigger signal to the control terminal of the triac TRC based on the detection result.

The triac TRC is a type of a bidirectional three-terminal thyristor and functions as a phase control element. The control terminal of the triac TRC is connected to a trigger output circuit 7
And the two signal terminals are brought into conduction by the trigger signal. The brightness of the incandescent lamp LP is controlled by controlling the voltage supplied to the incandescent lamp LP by the phase control of the triac TRC.

FIG. 2 shows a timing chart of this operation. (A) is a power supply waveform rectified by the diode bridge DB, (b) is a synchronizing pulse signal generated by the synchronizing signal generating means 2 using the threshold shown in the drawing, and (c) is a synchronizing pulse signal. (D) is a clock signal counted by the second counter 32, and the first and second counters respectively count N and N / 2 during a half cycle. Count. (E) shows that the constant value A is added to the count result N / 2 counted by the second counter during the first half cycle of the trigger signal (N / 2 + A).
Are stored in the storage means 5 as firing angle data. After the next half cycle, the value of the firing angle data stored in the storage means 5 is compared with the count value of the first counter 31 by the comparator 6, and when these values match, the comparator 6 outputs a coincidence detection signal. The trigger signal output circuit receives the coincidence detection signal and outputs a trigger signal. Note that the time when the count value of the first counter 31 matches N / 2 is the center of the half cycle, and when A is set to zero, the dimming rate is 30%.

FIG. 3 shows a waveform whose phase is controlled by the triac TRC by the trigger signal generated in this manner. (A): The frequency of the AC power supply is 50 Hz
And (b) is a case where the frequency of the AC power supply is 60 Hz. Here, the predetermined constant value A is a value counted by the first counter in the period of 0.69 mS. In the case of 50 Hz, the phase angle at which the trigger signal is generated is (5 mS + 0.69 mS) / 10 mS × 180 ° = 10
10 and FIG. 11, the dimming rate at that time is about 17%, whereas in the case of 60 Hz, the phase angle at which the trigger signal is generated is (4.165 mS + 0. 69mS) /8.3mS×18
0 ° = 105.4 °, and the dimming rate at that time is about 15%. That is, 5
The difference between 0 Hz and 60 Hz is about 2%, and the difference in dimming rate is small enough to cause no practical problem. FIG. 4 shows the relationship between the time corresponding to the constant value A and the dimming rate. The vertical axis of this figure is the dimming rate of the incandescent lamp. The solid line in the figure is the case of the conventional phase control based on the zero cross point at 50 Hz and 60 Hz, and the horizontal axis in this case is the time from the zero cross point to the generation of the trigger signal. The dotted line in the figure indicates the case of the phase control according to the present invention with reference to the center of the half cycle for 50 Hz and 60 Hz, and the horizontal axis indicates the time from the center of the half cycle until the trigger signal is generated. However, the origin of both is 4.165
The relationship in the case of the phase control according to the present invention at 60 Hz shifted by mS is drawn so as to match the relationship in the case of the conventional phase control at 60 Hz (indicated by a solid line in the drawing).

From this figure, for example, in the case of a dimming control device that controls the dimming rate to 25% with an AC power supply of 60 Hz,
If the same device is used on a 50 Hz AC power supply,
It can be seen that there is a difference of about 15% in the dimming rate in the conventional phase control device, but there is almost no difference in the phase control device according to the present invention. FIG. 5 shows an embodiment of the dimming control device according to the second aspect of the present invention. This dimming control device 1a includes a synchronizing signal generating means 2, a trigger generating means TG including a counter 3, an arithmetic circuit 4a, a storage means 5, a comparator 6, and a trigger output circuit 7, and a triac TR.
C, and a diode bridge DB, and are connected to the incandescent lamp LP and the AC power supply AG.

The synchronizing signal generating means 2 outputs a pulse from the synchronizing signal generating means every half cycle from immediately after the zero crossing point to immediately before the next zero crossing point, as in the above embodiment.

The synchronizing signal of the synchronizing signal generating means 2 is "
During the period of 1 ", the counter 3 counts the clock signal of a constant frequency. Here, the clock signal counted by the counter 3 is assumed to be sufficiently higher than the frequency of the AC power supply.

The arithmetic circuit 4 counts a half cycle of the counter 3, that is, from the time when the synchronization signal of the synchronization signal generating means 2 changes from "0" to "1", until the result changes from "1" to "0". A predetermined value A is added to 倍 of the counting result of counting the clock signal of the constant frequency during the period of
Store as firing angle data. This value A is a value corresponding to a preset light control level, as in the above embodiment.

The storage means 5 is a storage means for storing the operation result of the operation circuit as in the above embodiment. This storage means 5 is constituted by a register or the like, and holds a calculation result obtained from the count result of the immediately preceding half cycle during a half cycle.

The comparator 6 compares the count value of the counter 3 with the value of the firing angle data stored in the storage means 5 and detects whether or not these values match.

The trigger output circuit 7 is provided in the same manner as in the previous embodiment.
A trigger signal is output to the control terminal of the triac TRC based on the detection result of the comparator 6.

The triac TRC is a kind of bidirectional three-terminal thyristor and functions as a phase control element. The control terminal of the triac TRC is connected to a trigger output circuit 7
And the two signal terminals are brought into conduction by the trigger signal. The brightness of the incandescent lamp LP is controlled by controlling the voltage supplied to the incandescent lamp LP by the phase control of the triac TRC.

Therefore, in the dimming control device of this embodiment,
Since only one counter can be used, and the operation of 倍 times can be relatively easily realized by bit shift or the like, the dimming control device can be realized simply and inexpensively. For the same reason as the device, 50
When used in an AC power supply of 60 Hz and 60 Hz, there is almost no difference in the dimming rate.

FIG. 6 shows an embodiment of the automatic light control device according to the present invention. The automatic light control device 60 includes a Fresnel lens FL, a pyroelectric element 6
1, a human body detecting means 66 composed of a first amplifier circuit 62, a second amplifier circuit 63 and a comparison circuit 64, and a dimming control circuit 65, which are connected to a lighting load LP and an AC power supply AG. .

The Fresnel lens FL transmits far infrared rays radiated from a human body or the like existing in the detection area SA to the pyroelectric element 6.
Focus on 1. The pyroelectric element 61 receives far-infrared rays radiated from the floor or the like when the human body M does not exist, but also receives far-infrared rays of the human body M when a person enters the detection area SA. , And outputs the change as a voltage change. Each of the first and second amplifier circuits 61 and 62 includes an amplifier circuit and a band-pass filter. In such a human body detection device, the amplifier circuits 61 and 62 usually include
Since it is necessary to obtain a large gain, such a two-stage configuration is adopted. The amplifier circuit amplifies the output voltage of the pyroelectric element,
The bandpass filter peaks around 1 Hz so as to maximize the sensitivity of the walking speed of a normal human body, and removes low-frequency and high-frequency. The comparison circuit 64 compares the output waveform of the amplifier 63 with a window comparator having upper and lower thresholds, and outputs a comparison result. The dimming control circuit 65 turns on the illumination load LP for a certain period according to the output of the comparison result, or a predetermined period corresponding to a predetermined dimming level with reference to the center of a half cycle for dimming. This is a device that generates a trigger signal after elapse and performs phase control, and is configured by the dimming control device 1 or 1a.

Therefore, the same device can be used at 50 Hz and 60 Hz.
In this case, an automatic dimming control device that hardly causes a difference in dimming rate when used in the AC power supply can be realized.

As can be understood from the above description, according to the dimming control method according to the present invention as set forth in claim 1, and according to the dimming control apparatus as set forth in claims 2 and 3, the frequency of the AC power supply is 50 Hz. , 60 Hz, the center of the half cycle of the AC power supply is automatically detected by a simple method, the firing angle data is defined according to the dimming rate, and the conduction of the phase control element can be controlled. In particular, a small dimming rate, especially a dimming rate of 20% or more, which could not be accurately adjusted by the conventional dimming control device.
Even in the case of a dimming rate of about 25%, dimming can be accurately performed by a simple method.

Further, since the above effects can be obtained without determining the frequency of the AC power supply, a dimming control device capable of dimming with high accuracy can be provided at a low price. Furthermore, if the automatic dimming control device according to claim 4 incorporating the dimming control device is used, when the presence or absence of a human body in the detection area of the sensor is detected and the brightness of the lighting load is automatically dimmed, In addition, light can be accurately adjusted even in the case of a small dimming rate. That is, when the lighting fixture is dimly lit and a human body is detected, the dimming rate at the time of dark lighting when the dimming rate is set to 100% is accurately adjusted to 20 to irrespective of the power supply frequency. About 25%,
As compared with the case where the lighting is continued at the dimming rate of 100%, the minimum illuminance that can illuminate the surroundings as the lighting fixture can be secured while obtaining a sufficient energy saving effect.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a dimming control device according to the present invention described in claim 3;

FIG. 2 is an example of a timing chart showing a basic operation.

FIG. 3 is a diagram showing an example of a waveform whose phase is controlled by the dimming control device according to the present invention.

FIG. 4 is a diagram illustrating a relationship between a time until a trigger and a dimming rate.

FIG. 5 is a diagram showing a configuration of an embodiment of a dimming control device according to the second aspect of the present invention.

FIG. 6 is a diagram showing a configuration of an embodiment of an automatic dimming control device according to the present invention described in claim 4;

FIG. 7 is a diagram illustrating a configuration of a conventional dimming control device.

FIG. 8 is a diagram showing a configuration of a conventional automatic light control device.

FIG. 9 is a diagram showing a waveform whose phase is controlled by a conventional dimming control device.

FIG. 10 is a diagram showing a relationship between a phase angle and a voltage effective value.

FIG. 11 is a diagram showing the relationship between the effective voltage value of the incandescent lamp and the dimming rate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Dimming control device 2 ... Synchronous signal generation means TG ... Trigger generation means 3 ... Counter 31 ... First counter 32 ... Second counter 5 ... Storage means 66 ・ ・ ・ Human body detection means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-332496 (JP, A) JP-A-60-236494 (JP, A) JP-A-62-250091 (JP, A) JP-A-59-1984 83398 (JP, A) JP-A-54-115576 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05B 37/02

Claims (4)

(57) [Claims] An output of an AC power supply is controlled in phase to control an illumination load.
In a dimming control method for controlling brightness,The half cycle of the AC power supplied to the lighting load is
Is counted in advance by the clock signal of
2 and further set in advance according to the target dimming rate.
The value obtained by adding the corrected value is calculated as the firing angle, The AC power supplied to the lighting load is
While counting by the lock signal, the AC power supply
A trigger signal is generated each time the angle is reached, and the phase control element is
By letting Control the brightness of the lighting load
And a dimming control method. 2. A dimming control device for controlling the brightness of an illumination load by controlling the phase of an output of an AC power supply, comprising: a first counter for counting a half cycle of the AC power supply by a clock signal of a predetermined frequency; Storage means for storing, as firing angle data, a value obtained by adding a correction value set in advance according to a target dimming rate to a value of の of the count value of the counter 1; Comparing means for comparing the count value of the counter with the firing angle data stored in the storage means, wherein the comparing means determines that the count value of the first counter matches the firing angle data; A dimming control device configured to generate a trigger signal every time to conduct a phase control element. 3. A dimming control device for controlling the brightness of a lighting load by controlling the phase of an output of an AC power supply, wherein a first counter for counting a half cycle of the AC power supply by a clock signal having a predetermined frequency, A second counter that counts a half cycle of the AC power supply using a clock signal having a frequency half the clock signal of the first counter, and a first counter and a second counter that count the clock signal in the half cycle of the AC power supply. Storage means for storing, as firing angle data, a value obtained by adding a correction value preset according to a target dimming rate to a value obtained by counting the second count value by the first counter after the counting; And a count value of the first counter,
Comparing means for comparing the firing angle data with the firing angle data stored in the storage means, and each time the comparing means determines that the firing angle data matches the firing angle data based on the count value of the first counter, A dimming control device configured to generate and conduct a phase control element. 4. A dimming control device according to claim 2 or 3, wherein the dimming control device is configured to detect a human body in the detection area. A dimming control device characterized by controlling and automatically dimming.