JP2977063B2 - Light control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dimmer provided with a digital function generator.

[0002]

2. Description of the Related Art Conventionally, in an analog type dimming device, various circuit configurations have been proposed for a function generating means for obtaining a required dimming curve characteristic.

[0003]

However, complicated circuit configurations and constant adjustments have been necessitated, and the required dimming curve characteristics can only be imperfectly realized. That is, it cannot be commercialized without finding a compromise. Particularly, recently, the kinds of required dimming curve characteristics have increased, and the limit has been clarified in the analog function generating means. In view of the above circumstances, the present invention provides a dimming device including a function generating unit based on digital data capable of accurately achieving a required dimming curve characteristic. It solves the inherent problem that was impossible.

[0004]

According to the present invention, a signal generated from a function generator is supplied to a D / A converter in synchronization with an AC power supply, and the output of the D / A converter is compared with a variable DC voltage. A phase control element provided with a comparison means, and a phase control element based on the output of the phase control means to control the phase of the light source.The function generation means includes an address corresponding to the phase of the AC power supply. , it is set bit data corresponding to the address, bit data, AC power phase
Near the end of the address corresponding to the vicinity of the start point of the address, and set to change rapidly in response to the slight change of the address, and also correspond to the start point of the AC power supply phase
Thus, a dimming device is set in which the changed data value is set almost uniformly up to the end of the address.

[0005]

According to the present invention, the function generating means stores the dimming curve characteristics as digital data and can accurately realize the required dimming curve characteristics, particularly, a plurality of dimming curve characteristics. As described above, the D / A is achieved by the unique bit data characteristic from the vicinity of the end to the end of the address, which can be accurately realized by the digital function generating means.
When the light source is supplied to the phase control means having a comparison means based on a comparison with the variable DC voltage through the conversion means and the light source is phase-controlled through the phase control element, the trigger signal for the phase control is extremely fast. Never come to As a result, the conduction phase angle of the phase control element is not excessively advanced, so that unstable conduction of the phase control element near the zero crossing of the AC power supply can be prevented, and the flicker of the light source can be prevented.

[0006]

An embodiment of the present invention will be described with reference to the drawings.

In this embodiment, a signal generated from a function generator 2 is supplied to a D / A converter 3 in synchronization with an AC power supply 1, and the output of the D / A converter 3 is compared with a variable DC voltage. A function is provided to the phase control means 4 provided with the comparison means 4a, and the phase of the phase control element 13 is controlled by the output of the phase control means 4 to control the phase of the light source 5.
Is set with an address corresponding to the phase of the AC power supply 1 and bit data corresponding to the address.
In the vicinity of the end of the address corresponding to the vicinity of the starting point of the phase of the AC power supply 1, it is set so as to rapidly change in response to a very small change of the address .
The changed data value is set almost uniformly up to the end of the address corresponding to the start point of the phase .

[0008] The present embodiment will be described from another viewpoint.
A configuration in which a signal generated from the function generation means 2 in synchronization with the AC power supply 1 is supplied to the phase control means 4 via the multiplication type D / A conversion means 3 to control the phase of the light source 5; Is supplied to the D / A conversion means 3 through the voltage fluctuation correction means 7. Further, a function selecting means 8 for selecting a specific function from a plurality of functions of the function generating means 2 and a signal interposed between the voltage fluctuation correcting means 7 and the D / A converting means 3 based on a signal selected by the function selecting means 8 A specific correction element (for example, 7a) is automatically selected from the plurality of correction elements 7a, 7b,... Of the voltage fluctuation correction means 7 and supplies a specific correction signal to the D / A conversion means 3. 9 is provided.

More specifically, the AC power supply 1 is connected to the voltage detecting means 6 via the transformer 10. Further, the transformer 10 is connected to the address control means 12 via the synchronization signal generation means 11, and the function generation means 2 sends bit data to the D / A conversion means 3 by the address control means 12. The output of the D / A conversion means 3 is supplied to a phase control means 4 having a comparison means 4a, and controls the phase of a light source 5 of an incandescent lamp or a fluorescent lamp via a phase control element 13 such as a triac or thyristor. Reference numeral 14 denotes a clock generation unit connected to the address control unit 12, and reference numeral 15 denotes a DC power supply which is supplied to the dimming control unit A and the phase control unit 4.

To explain the operation of this embodiment, the synchronizing signal generating means 11 sends a power synchronizing signal synchronized every half cycle of the AC power supply 1 to the address control means (address counter) 12. The address control means 12 is reset by the power supply synchronizing signal, specifies the address of the function generation means 2 stored in ROM for each half cycle of the AC power supply 1 starting from address 0, and designates the bit data as D / A.
The data is read out by the conversion means 3. As shown in FIG. 3, the function generating means 2 sets an address corresponding to the phase of the AC power supply 1 and bit data corresponding to the address to correspond to the dimming curve characteristic.

The D / A conversion means 3 multiplies the dimming data consisting of the set of bit data by n times (for example, 4 times) and converts it into a dimming curve which is an analog signal. This dimming curve signal is supplied to the comparing means 4a of the phase control means 4, and is compared with a variable DC voltage (DC 0 to 10V) supplied from a fader (not shown) to form a trigger signal. Then, the phase of the light source 5 is controlled by the phase control output by the phase control element 13.

Here, if the characteristics of the function generating means 2 shown in FIG. 3 are described in correspondence with the variable DC voltage (shown by a horizontal dotted line) applied to the comparing means 4a by the operation of the fader, normally, for example, 6 V When there is a DC voltage as shown by the horizontal dotted line,
The above-described trigger signal is generated at the phase as shown by the vertical dotted line a,
Starting from this, the phase of the light source 5 is controlled. However,
In order to cope with a case where the DC voltage exceeds 10 V for some reason, as described above, the bit data is set so as to change abruptly in the vicinity of the end of the address in response to a very small change in the address. The changed data value is set almost uniformly up to the end of. In such a case, the trigger signal does not come to the left (that is, earlier in phase) than the vertical dotted line b due to the unique bit data characteristic from the vicinity of the end to the end of the address as described above. Thereby, the phase control element 1
Since the conduction phase angle of the phase control element 3 is not too advanced, unstable conduction of the phase control element 13 near the zero cross of the AC power supply 1 can be prevented, and the light source 5 can be prevented from flickering.

Next, as described above, according to the configuration in which the signal from the voltage detecting means 6 for detecting the voltage fluctuation of the AC power supply 1 is supplied to the D / A conversion means 3 via the voltage fluctuation correcting means 7, It is possible to correct the voltage fluctuation of the power supply 1 (for example, to stabilize the amount of light of the light source 5 and the effective power applied to the light source 5). Becomes That is, the correction for the voltage fluctuation of the AC power supply 1 differs depending on the type of the dimming curve characteristic (for example, the second power, the 2.3 power, the third power, ...).
If this correction cannot be made properly, it will be bad.

As described above, the function selecting means 8 selects a specific function from a plurality of functions of the function generating means 2,
A specific correction element (for example, from a plurality of correction elements 7a, 7b,... Of the voltage fluctuation correction means 7 based on a signal interposed between the voltage fluctuation correction means 7 and the D / A conversion means 3 and selected by the function selection means 8). 7a) is provided by a correction element selection means (data selector, multiplexer, etc.) 9 which is automatically selected and supplies a specific correction signal to the D / A conversion means 3. That is, function selection means 8 (switch)
, A specific correction element (for example, 7a) is automatically selected from the plurality of correction elements 7a, 7b,... Of the voltage fluctuation correction means 7 in accordance with the selected function, and D / A converted. A specific correction signal is supplied to the means 3 and the D / A
It is multiplied by the conversion means 3 and output. Individual correction elements 7
a, 7b,... have a group of amplifiers with different amplification factors. An appropriate amplifier is selected according to the function to be used, and an accurate correction is made according to the selected function. In addition, a method may be used in which one amplifier is used and various feedback resistors having different values are prepared, and one of the resistors is automatically selected, and as a result, the amplification factor is different. The correction result is as shown in FIG. 4. A dimming curve is drawn when the voltage of the AC power supply 1 is three, and the higher the voltage, the higher the voltage in accordance with the waveforms A, B and C corresponding to 115V, 100V and 90V. , The trigger signal starts with a lag phase, and the phase control output also has a lag phase and is corrected.

[0015]

As described above, according to the present invention, the conduction of the phase control element is achieved by the unique bit data characteristic from the vicinity of the end to the end of the address, which can be precisely realized by the digital function generating means. Since the phase angle is not excessively advanced, it is possible to prevent unstable conduction of the phase control element near the zero crossing of the AC power supply, and to provide a dimming device that can prevent flickering of the light source.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing an internal configuration of the voltage fluctuation correction means.

FIG. 3 is a characteristic diagram of the function generating means.

FIG. 4 is a waveform diagram of each part.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 AC power supply 2 Function generation means 3 D / A conversion means 4 Phase control means 4a Comparison means 5 Light source 13 Phase control element

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-98792 (JP, A) JP-A-60-68591 (JP, A) JP-A-5-242975 (JP, A) 36886 (JP, A) Japanese Utility Model 62-126095 (JP, U) Japanese Utility Model Application 3-131099 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H05B 37/02 H05B 39 / 04-39/08

Claims (1)

(57) [Claims] 1. A phase control system comprising: a signal generated from a function generator in synchronization with an AC power supply; and a controller for comparing the output of the D / A converter with a variable DC voltage. The phase generator controls the phase of the light source by controlling the phase of the phase control element based on the output of the phase controller.The function generator includes an address corresponding to the phase of the AC power supply and bit data corresponding to the address. The bit data is set so as to rapidly change in response to a slight change in the address near the end of the address corresponding to the vicinity of the starting point of the phase of the AC power supply ,
A dimmer in which the changed data value is set almost uniformly up to the end of the address corresponding to the start point of the phase of the AC power supply .