JP2676999B2 - Light control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention relates to a digital control dimmer for use in large theaters, halls, TV studios and the like.

(Prior Art) Conventionally, an analog control type light control device has been used in which an output when light control is performed with an analog signal of 0 to 10 V is fed back as an analog value and voltage is corrected by an operational amplifier. However, in recent years, digital control type dimmers have come to be used because of the desire to obtain uniform characteristics with respect to aging and temperature changes.

This digital control type dimmer is shown in FIG. 6 (a).
256 or 128 half cycles of the output of the AC power supply shown in
A basic pulse that is evenly divided, and turns on the thyristor at the timing of the basic pulse corresponding to the dimming level data given by 8 bits (the timing of the 122nd pulse in the figure) and exchanges it with the fluorescent lamp that is the load. Supply the output of the power supply and turn off the thyristor at the next zero cross point Z ₀ to stop the output of the AC power supply. Less than,
By repeating the operation in the same manner, accurate light control is performed in which the output shown by the hatching in FIG. 6B is applied to the load.

(Problems to be Solved by the Invention) However, when the above-mentioned digital control dimmer is used in a large capacity system having a large number of loads, a temporary voltage drop occurs, for example, as shown in FIG. a)
As shown in, the phenomenon that the AC power supply and the output are distorted occurs. If the digital control described with reference to FIG. 6 is carried out as it is in the state where this phenomenon has occurred, an insufficient output as shown by d in FIG. There was a problem that it became dark.

The present invention has been made in order to solve the problems of the conventional digital control type dimmer, and an object thereof is to be able to maintain the dimming level with respect to the fluctuation of the output voltage of the AC power supply, and to set it constantly. Another object of the present invention is to provide a dimming device that enables illumination at a dimming level.

[Configuration of the invention]

(Means for Solving the Problem) In the present invention, the number of pulses of this output is increased by feeding back the output of the power-on / off means for turning on / off the output of the AC power supply for dimming. It is detected whether it corresponds to the state of decrease or not, and ON control is performed at the timing when the basic pulse number is increased or decreased corresponding to the detected increase / decrease pulse amount to control the supply of the AC power output to the load. I did it.

Further, in the present invention, when the half cycle of the output of the AC power supply is divided from the current output of the AC power supply and the output of the normal time by changing the pulse width, division is performed at the timing of each pulse of the basic pulse in the normal time. The pulse width is varied depending on whether or not the ON control is performed to control the supply of the AC power output to the load.

(Operation) According to the light control device having the above configuration, the output of the power supply on / off means is set by changing which pulse of the basic pulse the on control is performed according to the fed back output of the power supply on / off means. By changing so as to correspond to the dimming level data, the correction according to the distortion of the output is performed.

Further, according to the dimmer having the above configuration, it is always possible to detect what kind of pulse width is divided into the current output of the AC power supply and the ON control has the same pulse timing as the ON control in the normal state. Therefore, when the output of the AC power supply is distorted, the pulse width is changed according to this distortion and the on-control phase is corrected. The dimming level related to the setting can be secured without changing.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram of one embodiment of the present invention. In the figure, reference numeral 1 is an AC power supply, which outputs, for example, 100 V, 60 Hz. The output of the AC power supply 1 is given to an ON / OFF operation unit 2 and a basic pulse generation unit 3 which are power supply ON / OFF means composed of a thyristor or the like. The on / off operation unit 2 performs an on / off operation based on the output of the gate amplifier 4 and performs an operation of passing or not passing the output of the AC power supply 1 to the load 5 such as a fluorescent lamp. The basic pulse generating unit 3 creates a basic pulse CK obtained by dividing each half cycle of the output of the AC power supply 1 into 256 and a zero-cross pulse P _Z for each zero-cross point (corresponding to Z ₀ in FIG. 6 (a)). It is given to the trigger circuit 6. The output of the on / off operation unit 2 is given to the A / D converter 7, digitized and given to the correction data creating unit 8. A dimming level setting unit 9 including a keyboard input device is connected to the correction data creating unit 8,
8-bit dimming level data D is given.

In the correction data creation unit 8, the integrated value data of the voltage when the ON control is performed from each pulse position when the output of the AC power supply 1 is normal and the output is divided into 256 by the basic pulse CK is held in the memory table. ing. On the other hand, the correction data creation unit 8 is supplied from the A / D converter 7 with data obtained by dividing the output of the on / off operation unit 2 into 256 in half cycles and digitizing the data. That is, the correction data creation unit 8 is provided with the digital data of the output when the ON control is performed in the half cycle of the output of the AC power supply 1. Therefore, the correction data creation unit 8 accumulates the digital data, obtains an integral value (actually the sum of the digital data) of the output of the on / off operation unit 2 having the waveform shown in FIG. The integrated value data that is the same as or closer to the same integrated value is obtained by referring to the table, and the ON-control pulse position data corresponding to this integrated data is extracted. That is, at present, the ON control is performed, for example, at the 126th pulse shown by the wavy line in FIG. 2B, but because of the waveform distortion, the output shown in FIG. Therefore, when the normal output is dealt with, this corresponds to when the ON control is performed at the 129th pulse as shown in FIG. 2B, and “129” is obtained as the pulse position data of the ON control. On the other hand, from the dimming level setting unit 9 as the dimming level data D “12
Since "6" is given, the correction data creating means 8 obtains the difference "3" and loads minus 3 into the correction data latch circuit 10 in order to perform ON control earlier by 3 pulses of the basic pulse CK. The latch data of the correction data latch circuit 10 is given to the trigger circuit 6. The trigger circuit 6 adds the latch data "-3" of the correction data latch circuit 10 to the 126th pulse which is currently performing the ON control, and generates a trigger pulse to perform the ON control at the 123rd pulse. That is, counting of the basic pulse CK is started from the previous zero cross pulse P _Z , an ON control trigger pulse is generated at the 123rd pulse, and an OFF control trigger pulse is generated at the next zero cross pulse P _Z. During this trigger pulse, the gate amplifier 4
From this, an ON control signal is given to the ON / OFF operation unit 2.
As a result, the output of the on / off operation unit 2 has a waveform rising from the 123rd pulse as shown in FIG. 3 (a), and as shown in FIG. 3 (b) due to the decrease due to the waveform distortion. When the AC power supply 1 outputs normally, it corresponds to the waveform for which the ON control is performed from the 126th pulse. In addition,
In this embodiment, the case where the ON correction is completed by 3 pulses earlier can be completely corrected, but the inclination of the output waveform of the ON / OFF operation unit 2 varies depending on the position where the OFF control is performed. The output may be insufficient or excessive even if the ON control is performed for 3 pulses earlier.
In such a case, further correction is performed in the next half cycle.
However, when the waveform distortion itself ends in a half cycle, the human does not feel dark, so that the required dimming level can be maintained by so-called follow-up control as in the present embodiment. Further, when the peak value of the output of the AC power supply 1 becomes larger than that in the normal state, the OFF control timing is controlled to be delayed.

Next, another embodiment of the present invention will be described with reference to FIGS. In FIG. 4, the same components as those in FIG. 1 are designated by the same reference numerals and the description thereof is omitted. In this embodiment, the output of the AC power supply 1 is given to the waveform change detection unit 11. The waveform change detection unit 11 includes, for example, an A / D converter, and A / D converts the output. Here, the higher the frequency of the sampling clock for A / D conversion, the better, for example, 60 × 2560.
0 Hz. The waveform change detection unit 11 gives the obtained digital data relating to the A / D conversion output to the pulse width correction unit 12. The pulse width correction unit 12 outputs 256 half cycles of the output of the AC power supply 1.
It has a memory table in which digital data of the effective value (area) of each section when divided is stored. The pulse width correction unit 12 adds the given digital data from the terminal side of the half cycle of the output of the AC power supply 1 as shown by the arrow X in FIG.
The addition is continued until the digital data in the corresponding section on the terminal side of the half cycle divided into 6 (or until it comes closest). Then, it is stored how many sampling clocks of digital data are coincident or closest to each other. This operation is performed every half cycle of the output (in the direction of arrow X).
That is, when the output obtained at present is divided by the pulse width of the area S ₁ , S ₂ ... of each section obtained by dividing the half cycle output at the normal output shown in FIG.
In FIG. 5 (b), S ₁ ′, S ′ ₂ , ... are S ₁ = S ′ ₁ and S ₂ = S ′.
₂ is detected and the pulse width of each section is corrected from the end side of the output half cycle. However, if the pulse width is changed for all sections (256 sections) of the half cycle,
Since the area of the output of FIG. 5 (b) is smaller than the output of FIG. 5 (a), the section to be corrected in advance is defined as the section of the latter half of the half cycle such as 80%, and the remaining portion in the section of the first half of 20% The pulse width is corrected so that the pulses (remaining for 256 divisions) are arranged at equal intervals. The pulse width corrected in this way can be changed in units of 1/60 × 1/25600 (Sec) because the sampling clock is 60 × 25600 Hz. The pulse width correction unit 12 gives the data of the pulse width determined as described above to the basic pulse generation circuit 13. The basic pulse generation circuit 13 receives the output of the AC power supply 1, detects a zero cross point, and triggers a basic pulse having a pulse width corresponding to the pulse width data output from the pulse width correction unit 12 from the zero cross point. Give to 14. On the other hand, the data latch circuit 15 latches the dimming level data supplied from the dimming level setting unit 9, and the trigger circuit 14
Given to. The trigger circuit 14 counts the basic pulse output from the basic pulse generation circuit 13 and counts the data latch circuit.
When the number of pulses corresponding to the dimming level data latched in 15 is reached, the ON control trigger pulse is output,
When the number of pulses reaches 256, it outputs a trigger pulse for off control and resets itself. Based on the trigger pulse, the gate amplifier 4 gives a control signal to the on / off operation unit 2 during the on control. As a result, the effective value (area) of the output of the AC power supply 1 passed from the ON control to the OFF control is made equal to the effective value when the ON control is performed corresponding to the dimming level data when the output is normal. . FIG. 5 shows that the phase of the 126th pulse is changed. In this embodiment as well, the follow-up control is performed as in the embodiment of FIG. 1, but the dimming level can be effectively maintained for the human eye. Further, it goes without saying that the correction is performed even when the peak value of the output of the AC power supply 1 becomes higher than the normal value.

In the above embodiment, the crest value data obtained when the half cycle of the output of the AC power supply 1 is divided into 256 (generally n: natural number) is provided in the memory table. The output may be obtained from a power supply that produces the output, and the output may be digitized and used. Further, each numerical value is merely an example and can be changed as appropriate. Further, the correction data creation unit 8, the pulse width correction unit 12 and the like may be configured as a microcomputer.

〔The invention's effect〕

As described above, according to the present invention, since the number of basic pulses to be ON-controlled when the output of the AC power supply fluctuates is increased or decreased, it is possible to apply the same electric power as the output during normal operation to the load, The required dimming level can be maintained.

Further, according to the present invention, the pulse width of the basic pulse is changed when the output of the AC power supply changes, and the effective value (area) of the output of the AC power supply in each pulse section matches the corresponding effective value at the normal time. Therefore, even if the ON control is performed at the timing of the same pulse number as in the normal state, the same electric power as the output in the normal state can be applied to the load and the required dimming level can be maintained.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIGS.
FIG. 4 is a waveform diagram for explaining the operation of the embodiment of FIG. 1, FIG. 4 is a block diagram of another embodiment of the present invention, and FIG. 5 is for explaining the operation of the embodiment of FIG. Waveform diagram of Figure 6,
FIG. 7 is a waveform diagram for explaining the operation of the conventional light control device. 1 ... AC power supply, 2 ... ON / OFF operation part 3,13 ... Basic pulse generation circuit 4 ... Gate amplifier, 5 ... Load 6,14 ... Gate amplifier, 7 ... A / D converter 8 ... Correction data creation unit 9 …… dimming level setting unit 10 …… correction data latch circuit 11 …… waveform change detection unit 12 …… pulse width correction unit 15 …… data latch circuit

Claims (2)

(57) [Claims] 1. A power supply ON / OFF means for turning on the output of the AC power supply at any position of a half cycle of the output, and turning it off at a zero cross point that comes thereafter to give it to the load, and of the output of the AC power supply. There are provided basic pulse creating means for creating a basic pulse by dividing a half cycle into n, and storage means for storing voltage data when the power supply on / off means is on-controlled at each pulse position of the basic pulse when the AC power supply is normal. Then, the output of the power supply on / off means is obtained, and by comparison with the voltage data stored in the storage means, the output is output for each half cycle of the basic pulse at the normal output of the AC power supply. ON control pulse number detection means for detecting whether or not the ON control is performed at the pulse position, data for setting the dimming level of the load, and the ON control pattern The pulse position of the basic pulse on which the ON control corresponding to the set dimming level is to be performed and the pulse position of the basic pulse detected by the ON control pulse number detecting means based on the detection result by the pulse number detecting means. Compensation pulse number determining means for comparing and determining the basic pulse number to be increased and decreased, and a power source for controlling by changing the ON control timing in the power on / off means according to the basic pulse number determined by the correction pulse number determining means. A light control device comprising an on / off control means. 2. A power-on / off means for turning on the output of the alternating-current power supply at any position of a half cycle of the output, and turning it off at a zero cross point that comes thereafter to give it to the load, when the alternating-current power supply is normal. There is a storage means for storing the effective value of each output obtained by dividing the half cycle of the output into n at equal time intervals, and the effective value of each output stored in this storage means and the current ON period of the AC power supply. When the output of the ON period is divided based on the output of the pulse width, the pulse width is increased or decreased so that the area of the divided output matches the corresponding effective value of each output stored in the storage means. A pulse width determining means for determining, a basic pulse generating means for generating a basic pulse obtained by dividing a half cycle of the output of the AC power supply in correspondence with the pulse width determined by the pulse width determining means, and the negative pulse Receiving the dimming level data for setting the dimming level and the basic pulse output by the basic pulse generating means, and turning on the power on / off means at the pulse positions corresponding to the number of basic pulses corresponding to the dimming level data. And a power on / off control means for performing the above.