JPH10106758A - Dimmer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dimmer capable of preventing flickering or variation of brightness in dimming down and obtaining the constant illumination independent of variation in frequency or difference in frequency band of the power. SOLUTION: A dimmer has an illumination comparing means 4 which compares an actual illumination signal outputted from a illumination detecting means 2 with an illumination signal set with an illumination setting means 3 and outputs difference between them, a charging/discharging means 7 which synchronizes with a half period of commercial frequency and repeats charging/ discharging, a reference voltage generating means 5 which generates reference voltage corresponding to the amount of difference outputted from the illumination comparing means 4, a comparing means 8 which compares the reference voltage outputted from the reference voltage generating means 5 with charging/ discharging voltage outputted from the charging/discharging means 7, and a trigger signal output means 9 which outputs a trigger signal based on the compared result from the comparing means 8, and a phase control element 10 is controlled with the trigger signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase control type dimmer using a phase control element driven by a commercial frequency and a commercial power supply voltage.

[0002]

2. Description of the Related Art Generally, when dimming control of an incandescent lamp is performed by a dimmer, a phase control element such as a triac driven by a commercial frequency and a commercial power supply voltage is used. In this case, the trigger signal is supplied to the gate of the triac to control the on / off of the triac, thereby dimming an incandescent lamp connected to a commercial power supply via the triac.

Here, as the on / off control of the triac, a time control method in which a trigger signal is generated after a certain time from the zero-cross point of the commercial frequency is often used.

[0004]

However, in the above-described dimmer, the trigger signal for the triac on / off control is generated after a certain time from the zero-cross point of the commercial frequency. And the difference in the commercial frequency band such as 50 Hz and 60 Hz, the phase of the trigger signal generation position is shifted, and there is a problem that flickering, the brightness fluctuates, and the illuminance differs depending on the region. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to reduce fluctuations in commercial frequency
It is an object of the present invention to provide a light control device capable of preventing flicker and fluctuation of brightness during light control and obtaining a constant illuminance regardless of a difference between commercial frequency bands such as 0 Hz and 60 Hz.

[0006]

According to the first aspect of the present invention,
In a dimming device that dims an illumination load driven by a commercial power supply by phase control using a phase control element,
Illuminance detection means for detecting the brightness of the illumination load, illuminance setting means for presetting the desired brightness of the illumination load, an illuminance signal output from the illuminance detection means, and an illuminance signal set by the illuminance setting means Illuminance comparison means for comparing the two and outputting a difference between the two, a charge / discharge means for repeating charge / discharge in synchronization with a half cycle of the commercial frequency, and a reference corresponding to the magnitude of the difference output from the illuminance comparison means A reference voltage generating means for generating a voltage, a comparing means for comparing a reference voltage output from the reference voltage generating means with a charging / discharging voltage output from the charging / discharging means, based on a comparison result from the comparing means And a trigger signal output means for outputting a trigger signal. The trigger signal is used to control the phase control element.

According to a second aspect of the present invention, in the first aspect of the present invention, the illuminance detecting means includes an illuminance sensor and an illuminance detection circuit for converting a signal from the illuminance sensor into an illuminance signal. Is what you do.

According to a third aspect of the present invention, in the first aspect of the present invention, the illuminance detecting means includes a power monitoring circuit for detecting an amount of power supplied to the lighting load, and a power output from the power monitoring circuit. The power illuminance conversion circuit converts a signal into an illuminance signal.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a dimmer according to an example of the embodiment of the present invention.
3 is a signal waveform diagram of each part. The light control device of the present embodiment includes an illuminance sensor 1, an illuminance detection circuit 2, an illuminance setting circuit 3, an illuminance comparison circuit 4, a reference voltage generation circuit 5, a zero cross circuit 6, a charge / discharge circuit 7, a comparison circuit 8, a trigger signal output. It comprises a circuit 9, a triac 10, an incandescent lamp 11, and a commercial power supply 12. The illuminance sensor 1 detects the illuminance of the incandescent lamp 12, and the illuminance detection circuit 2 includes the illuminance sensor 1
Is converted into an illuminance signal. The illuminance setting circuit 3 is for presetting a desired brightness of the incandescent lamp 12, and outputs an illuminance signal corresponding to the desired brightness. The illuminance sensor 1 and the illuminance detection circuit 2 constitute illuminance detection means. The illuminance comparison circuit 4 includes an illuminance signal preset by the illuminance setting circuit 3 and the illuminance detection circuit 2.
Is compared with the illuminance signal output from the CPU to determine the difference. That is, the difference between the actual illuminance and the set value is obtained.

The charging / discharging circuit 7 takes in a zero-cross signal synchronized with a half cycle of the commercial frequency output from the zero-cross circuit 6, and performs charging and discharging in synchronization with the zero-cross signal.
Charging is performed at a constant gradient, and discharging is performed instantaneously.

The reference voltage generation circuit 5 generates a reference voltage according to the difference output from the illuminance comparison circuit 4. For example, when the actual illuminance is larger than the set value, that is, when the illuminance is too bright, the reference voltage is increased, and when it is opposite, the reference voltage is decreased. This operation is performed until there is no difference.

The comparison circuit 9 compares the reference voltage from the reference voltage generation circuit 5 with the charge / discharge voltage from the charge / discharge circuit 7, and when the charge / discharge voltage exceeds the reference voltage, the output is inverted.

The trigger signal output circuit 9 receives the inversion signal from the comparison circuit 8 and generates a trigger signal at a timing starting from the rise of the inversion signal.

A triac 10 as a phase control element is inserted between an incandescent lamp 11 as an illumination load and a commercial power supply 12, and the position (phase) of the commercial power supply to which a trigger signal from the trigger signal output circuit 9 is given. To control the power supply to the incandescent lamp 11 and dimming the incandescent lamp 11.

In the present embodiment, when the incandescent lamp 11 is too bright, the reference voltage from the reference voltage generating circuit 5 becomes large, and the timing of generating the trigger signal is delayed, so that the incandescent lamp 11 becomes dark and vice versa. In such a case, the incandescent lamp 11 is controlled to be bright. That is, feedback is applied so that the timing of generation of the trigger signal is such that the illuminance has a value set by the illuminance setting circuit 3. Can maintain a certain level of illuminance.

By changing the set value set by the illuminance setting circuit 3, it is possible to arbitrarily set the dimming rate although it is discrete.

FIG. 3 is a block diagram showing a light control device according to another embodiment of the present invention. This embodiment is different from the above-described embodiment in that the illuminance detection means is replaced by the power monitoring circuit 13.
And the power illuminance conversion circuit 14. Other configurations are the same as those of the above-described embodiment. The power monitoring circuit 13 detects the amount of power supplied to the incandescent lamp 12, and the power illuminance conversion circuit 14 includes a conversion table between the power amount and the illuminance. Is converted into illuminance and output as an illuminance signal. Other operations are the same as those in FIG.

[0018]

As described above, according to the first to third aspects of the present invention, dimming is performed by dimming an illumination load driven by a commercial power supply by phase control using a phase control element. In the device, illuminance detection means for detecting the brightness of the illumination load, illuminance setting means for setting a desired brightness of the illumination load in advance, an illuminance signal output from the illuminance detection means and the illuminance setting means Illuminance comparing means for comparing the illuminance signal and the difference between the two, and charging / discharging means for repeating charge / discharge in synchronization with a half cycle of the commercial frequency, and the magnitude of the difference output from the illuminance comparing means. Reference voltage generating means for generating a corresponding reference voltage; comparing means for comparing a reference voltage output from the reference voltage generating means with a charge / discharge voltage output from the charge / discharge means; Based on the result And a trigger signal output means for outputting a trigger signal, and the phase control element is controlled by the trigger signal. The feedback signal is applied so that the phase at which the trigger signal is generated does not change even when the commercial frequency changes.
Irrespective of the difference in the commercial frequency band such as 0 Hz, a dimming device capable of preventing flicker and fluctuation of brightness during dimming and obtaining a constant illuminance can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a light control device according to an embodiment of the present invention.

FIG. 2 is a waveform chart of each part according to the above.

FIG. 3 is a block diagram illustrating a schematic configuration of a light control device according to another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 illuminance sensor 2 illuminance detection circuit 3 illuminance setting circuit 4 illuminance comparison circuit 5 reference voltage generation circuit 6 zero cross circuit 7 charge / discharge circuit 8 comparison circuit 9 trigger signal output circuit 10 triac 11 incandescent lamp 12 commercial power supply 13 power monitoring circuit 14 power illuminance Conversion circuit

Claims (3)

[Claims] An illuminance detecting means for detecting the brightness of an illumination load, wherein the illumination load is controlled by phase control using a phase control element. Illuminance setting means for setting a desired brightness in advance, illuminance comparison means for comparing the illuminance signal output from the illuminance detection means and the illuminance signal set by the illuminance setting means and outputting a difference between the two, Charge / discharge means for repeating charge / discharge in synchronization with a half cycle of the commercial frequency, reference voltage generation means for generating a reference voltage corresponding to the magnitude of the difference output from the illuminance comparison means, and Comparing means for comparing the output reference voltage with the charging / discharging voltage output from the charging / discharging means, and a trigger signal output means for outputting a trigger signal based on a comparison result from the comparing means. Wherein the phase control element is controlled by the trigger signal. 2. The dimming device according to claim 1, wherein said illuminance detecting means comprises an illuminance sensor and an illuminance detection circuit for converting a signal from the illuminance sensor into an illuminance signal. 3. The illuminance detection means includes a power monitoring circuit for detecting an amount of power supplied to the lighting load, and a power illuminance conversion circuit for converting a power signal output from the power monitoring circuit into an illuminance signal. The light control device according to claim 1, wherein: