JP2012181934A - Illumination system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve an illumination system capable of detecting a zero cross of an AC voltage with accuracy and performing dimming by stable phase control based on an obtained zero-cross signal.SOLUTION: A zero-cross detector 14 detects a zero cross of a low-distortion AC voltage immediately after conversion into a low voltage from a secondary side 12b of a step-down transformer 12. The detection result is generated as a zero-cross signal. The zero-cross signal is transmitted to a dimming control part 13 side dimming the brightness of a light source via a transmitter 15 wirelessly. The dimming control part 13, based on the timing of the zero-cross signal, outputs from a controller 19 signals for performing phase control of an AC voltage which are inputted to dimmers 211-21n corresponding to a dimming desk 20 by using a dimming signal from the dimming desk 20 to perform dimming of light sources 221-22n connected to outputs of the dimmers 211-21n respectively.

Description

  Embodiments described herein relate generally to an illumination system that performs phase control of an alternating-current power supply voltage used in a theater, a television studio, or the like to perform light control.

  Conventionally, in a dimming device used in a production space such as a theater or a TV studio, tens to hundreds of lighting fixtures are installed, and a thyristor dimmer corresponding to each lighting fixture is connected. . The dimmer is supplied with the zero cross point of the AC voltage as a synchronization signal, and the zero cross point is used as a reference for the phase angle, and the ignition phase angle of the thyristor element is determined by the phase angle control signal to perform dimming of the load. .

JP 2007-115430 A

  When dimming lighting in TV studios or theaters, the range from several tens of meters to hundreds from the position where the high voltage power input to the building or the like is converted to a low voltage for lighting the light source to the position where it is input to the dimmer. Since it is about 10m long, the AC power supply is distorted due to the influence of the impedance of the AC power supply and the wiring impedance to the lighting system, or the lighting system cannot detect the zero cross normally due to the occurrence of voltage drop. There was a problem of doing.

  Therefore, an object of the present invention is to provide an illumination system capable of accurately detecting a zero-cross signal of an AC power supply voltage and performing dimming by stable phase control.

  In order to solve the above-described problems, according to an embodiment of the illumination system of the present invention, a zero-cross detector that detects a zero-cross of an AC power supply voltage and generates a zero-cross signal, and a timing and dimming signal of the zero-cross signal are used. And a dimming control unit that obtains a dimming voltage of a light source by performing phase control of the AC power supply voltage based on the zero cross signal is input to the dimming control unit using radio Features.

  According to the embodiment of the present invention, the zero cross of every half cycle of the AC power supply voltage can be accurately obtained, and as a result, the light source can be correctly dimmed according to the dimming signal.

It is a circuit block diagram for demonstrating 1st Embodiment regarding the illumination system of this invention. It is a more specific block diagram of the principal part of FIG. It is explanatory drawing for demonstrating the light control operation | movement of FIG. It is explanatory drawing for demonstrating the effect of 1st Embodiment. It is a circuit block diagram for demonstrating 2nd Embodiment regarding the illumination system of this invention. It is explanatory drawing for demonstrating the alternating voltage waveform of each phase of a three-phase four-wire system. It is a more specific block diagram of the principal part of FIG. It is explanatory drawing for demonstrating the transmission data of a zero cross signal. It is explanatory drawing for demonstrating the address data of FIG. It is explanatory drawing for demonstrating the light control output for dimming a light source. It is a circuit block diagram for demonstrating 3rd Embodiment regarding the illumination system of this invention. It is explanatory drawing for demonstrating the effect of 3rd Embodiment. It is explanatory drawing for demonstrating the effect of 3rd Embodiment at the time of setting it as a three-phase 4 wire system.

  Hereinafter, embodiments will be described in detail with reference to the drawings.

(First embodiment)
1 to 4 are for explaining a first embodiment relating to a lighting system. FIG. 1 is a schematic circuit configuration diagram, FIG. 2 is a specific configuration diagram of the main part of FIG. 1, and FIG. FIG. 4 is an explanatory diagram for explaining the operation of FIG. 2, and FIG. 4 is an explanatory diagram for explaining the effect of the first embodiment.

  In FIG. 1, reference numeral 11 denotes a high-voltage AC power source having a commercial frequency of 6.6 kV, for example, input to the primary side 12 a of the step-down transformer 12. The step-down transformer 12 converts the voltage into, for example, a low voltage of 100 V, and outputs it from the secondary side 12b as a power source for the dimming control unit 13 or the like. Further, the AC voltage on the secondary side 12b is input to the zero cross detector 14 that detects the zero cross. The zero-cross detector 14 detects a zero-cross of a sine wave AC voltage V <b> 1 (AC100V) input from the secondary side 12 b of the transformer 12. This zero cross detection is performed by forming a switching circuit that operates by detecting that the absolute value of the AC voltage V1 is equal to or lower than a predetermined voltage, for example, and detecting when these switching operations are switched. However, the zero cross detector 14 is not limited to the above-described one, and various types can be adopted. The zero cross signal detected by the zero cross detector 14 is sent to the transmitter 15 at the next stage. In the transmitter 15, the zero cross signal is converted into a zero cross signal by digital conversion and transmitted through the transmission antenna 16 using the transmission function.

  The zero cross signal transmitted from the transmitting antenna 16 is received by the receiver 18 via the receiving antenna 17 and input to the controller 19 embodied by the CPU of the dimming control unit 13 or the like. A 0 to 100% dimming signal from a dimming console 20 that performs dimming operation is input to the controller 19 in DMX format. Further, a phase control signal based on the dimming signal is output from the output of the controller 19 and input to the n dimmers 211 to 21n. The outputs of the dimmers 211 to 21n are input to the corresponding light sources 221 to 22n, respectively.

  A specific configuration example regarding dimming will be described with reference to FIGS. 2 and 3. Here, a configuration example of the dimmer 211 will be described as a representative.

  In FIG. 2, one side of the AC 100V on the secondary side 12b of the step-down transformer 12 is constituted by a series circuit of a switching circuit and a reactor L in which two thyristors 24 and 25 are connected in parallel with opposite polarity via a power line 23a. It is connected to the input side of the dimmer 211. The output side of the dimmer 211 is connected to one electrode of the light source 221. The other electrode of the light source 221 is connected to the other secondary side 12b of the transformer 12 through the power line 23b. The reactor L is used to suppress a steep current rise associated with the firing of the thyristors 24 and 25, and to reduce noise interference to an audio device provided in a theater or a television studio.

  The output of the controller 19 that inputs the zero-cross signal and the dimming signal detected by the zero-cross detector 14 and outputs them as a phase control signal synchronized with the zero-cross signal is input to thyristors 24 and 25 having gate electrodes connected in common. The

  Here, the dimming operation of FIG. 2 will be described together with FIG. FIG. 3A shows the AC voltage a input to the dimming control unit 13 and serves as a power source for driving the dimming control unit 13. The result of detection of the zero cross of AC 100V immediately after the secondary side 12b of the step-down transformer 12 by the zero cross detector 14 passes through the transmitter 15 and the receiver 18, and the controller 19 as the zero cross signal b shown in FIG. To enter. The term “immediately after the secondary side 12b” means a range in which the distortion necessary for obtaining the zero cross in the vicinity of the zero cross is obtained and in which the distortion is small. The distance is preferably within a few meters at most.

  A phase control signal c shown in FIG. 3C is output from the controller 19 based on the dimming signal obtained by operating an operation element (not shown) for the light source 221 of the dimming console 20 and the timing of the zero cross signal b. . FIG. 3D shows the dimming output of the dimmer 211 obtained based on the phase control signal c output from the controller 19, and the light source 221 is turned on by this output.

  FIG. 3 gives a 50% dimming example. That is, when the half cycle of the AC voltage a is defined as time t with reference to the zero cross signal b, the phase control signal c obtained from the output of the controller 19 based on the 50% dimming signal is changed from the zero cross signal b to t / 2. The controller 19 is pre-programmed so as to calculate so that

  From the output of the controller 19, a phase control signal c that rises in the middle part of the half cycle of the AC voltage a is input to the gate electrodes of the thyristors 24 and 25. The thyristor 24 causes a current to flow between the anode and cathode electrodes, and outputs the voltage shown in FIG. 3D from the output of the dimmer 211 up to the zero cross point of the AC voltage a, and the thyristor 24 is turned off. Similarly, when the next phase control signal c is input from the controller 19 to the gate electrodes of the thyristors 24 and 25, the thyristor 25 is turned on to pass a current between the anode and the cathode electrodes, until the zero cross point of the AC voltage a. The voltage shown in FIG. 3D is output from the output of the dimmer 211, and the thyristor 25 is turned off. Thereafter, the same operation is repeated every half cycle.

  When it is desired to change the dimming of the light source 221, the operation corresponding to the light source 221 of the dimming console 20 is operated, and the generation timing of the phase control signal c of the controller 19 is changed with respect to the zero cross signal b. Dimming of 0 to 100% is possible.

  FIG. 4 is for explaining the effect of this embodiment. The broken line in FIG. 4 (a) shows the power line 23a, when the voltage waveform is distorted due to the input or fluctuation of the load provided by branching in parallel. An example of an AC voltage waveform input to the dimming control unit 13 via 23b, and a solid line indicates an AC voltage waveform immediately after the secondary side 12b of the step-down transformer 12.

  When the zero cross of the alternating voltage input to the dimming control unit 13 is detected, the zero cross point is detected a plurality of times as shown in FIG. When dimming is performed based on this detection result, the zero cross cannot be detected normally or flickers, resulting in erroneous lighting. On the other hand, when the zero crossing of the AC voltage immediately after the secondary side 12b of the step-down transformer 12 with less distortion is detected, the zero cross detector 14 reliably detects the zero crossing as shown in FIG. Dimming by phase control can be performed.

  In this embodiment, a normal zero cross is detected at a place where a stable AC voltage is obtained that is not affected by the power source impedance, wiring impedance, or load side, and the detected zero cross signal is transmitted wirelessly, thereby causing an error. It becomes possible to prevent lighting. In addition, a filter circuit for removing power supply distortion on the dimming control unit 13 side becomes unnecessary.

(Second Embodiment)
5 to 10 are diagrams for explaining a second embodiment related to the lighting system, FIG. 5 is a circuit configuration diagram, FIG. 6 is a diagram for explaining transmission data of a zero cross signal, and FIG. 7 is a diagram. FIG. 8 is an explanatory diagram for explaining the three-phase zero-cross signal in FIG. 8, FIG. 9 is an explanatory diagram for explaining the three-phase address in FIG. 8, and FIG. 10 is a light source. It is explanatory drawing for demonstrating the light control output for adjusting light. In the following embodiments, the same or corresponding components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  In this embodiment, the phases of the R, S, and T phases by the three-phase four-wire system are sequentially shifted by 120 degrees as shown in FIG. 6, and each phase outputs a voltage of a commercial frequency of 200 V, for example, and the dimming control The light is input to each dimmer 211 to 21 n of the unit 13. In the dimming control unit 13, dimming of the light sources 221 to 22 n corresponding to the dimming signals by the operator of the dimming console 20 is performed for each of the R, S, and T phases.

  FIG. 7 shows a specific configuration example of the dimmer 211. The R phase of the dimmer 211 of the dimming controller 13 to which a three-phase four-wire AC voltage is input is the R dimmer 211r, the S phase is the S dimmer 211s, and the T phase is the T dimmer. 211t respectively. The zero cross of the R, S, and T phases shown in FIG. The other dimmers 212 to 21n are configured in the same manner.

  The R, S, and T phase zero cross signals detected by the zero cross detector 14 are sent to the transmitter 15. In the transmitter 15, as shown in FIG. 8, the address of each phase and the zero-cross signal are converted into serial data and transmitted via the transmission antenna 16. The transmitted zero-cross signal is received by the receiver 18 via the reception antenna 17, converted from serial data to parallel data, and input to the controller 19. The address of each phase is converted into data so that it can be identified, for example, which of the zero cross signals of the R, S, and T phases is 2 bits shown in FIG.

  The controller 19 outputs phase control signals to the dimmers 211 to 21n from the R, S, T phase zero-cross signals converted into parallel data and the dimming signal of the dimming console 20, respectively. For the R dimmer 211r of the dimmer 211, for example, when a 30% dimming signal is input from the console 20 to the controller 19, the voltage shown in FIG. 10B from the R dimmer 211r. Is output to the light source 221, and the light source 221 is turned on with dimming of 30%. For the S dimmer 211s of the dimmer 211, for example, when a 70% dimming signal is input from the console 20 to the controller 19, the voltage shown in FIG. 10C from the S dimmer 211s. Is output to the light source 222, and the light source 222 is turned on with 70% light control. Further, for the T dimmer 211t of the dimmer 211, for example, when a dimming signal of 50% is input from the console 20 to the controller 19, the T dimmer 211t is changed to FIG. The voltage shown is output to the light source 223, and the light source 223 is turned on with 50% light control.

  Similarly, an operator corresponding to the light source of the dimming console 20 according to the percentage of dimming of the light source connected to the output of each of the R, S, and T dimmers of the dimmer 212. , The dimming of the corresponding light source can be performed based on the timing of the dimming signal of the operator and the zero-cross signals of the R, S, and T phases.

  In this embodiment, it is possible to reduce the power loss, and the influence of the power source impedance and the wiring impedance while taking advantage of the characteristics of the three-phase four-wire system such as reducing the number and thickness of the electric wires for distributing the same power. It is possible to prevent erroneous lighting by detecting a normal zero cross at a place where a stable AC voltage that is not subject to noise is obtained and transmitting the detected zero cross signal wirelessly.

(Third embodiment)
FIG. 11 and FIG. 12 are for explaining a third embodiment relating to the illumination system, FIG. 11 is a circuit configuration diagram, and FIG. 12 is an explanatory diagram for explaining the effect of this embodiment.

  In this embodiment, a zero cross of a low-current commercial high-voltage AC voltage of 6.6 kV that is fed from an electric power company and input to the primary side 12a of the step-down transformer 12 is detected by the zero-cross detector 14, and the detection result is zero-crossed. The zero-cross signal is generated as a signal and transmitted to the dimming control unit 13. This embodiment is suitable for a case where the capacity of the step-down transformer 12 is relatively small, and the load-side power supply voltage waveform distortion is likely to occur immediately after the secondary side 12b.

  12A shows a voltage waveform on the primary side 12a of the step-down transformer 12, and FIG. 12B shows a voltage waveform on the secondary side 12b of the step-down transformer 12. The primary side 12a is an AC power supply of 6.6 kV, for example, and the secondary side 12b is an AC power supply of 100 V, for example, but the AC voltage input to the zero cross detector 14 is shown as the same value.

  As shown in FIG. 12 (b), when a light bulb as a light source provided in parallel separation is started at the phase indicated by the arrow P, an excessive rush current flows, and the portion indicated by the arrow P is distorted. appear. For this reason, the zero-cross detector 12 may erroneously detect, and as shown in FIG. 12C, there is a possibility that the dimming output level is lowered and the originally intended dimming state is not achieved.

  In this regard, as shown in FIG. 12A, the AC voltage on the primary side 12a of the step-down transformer 12 detects a zero cross of a sine wave with little distortion. Therefore, the light control output becomes a desired level, and the light source can be turned on by light control intended by the operator of the light control console 20.

  In this way, a zero cross of a commercial power supply voltage with excellent characteristics inputted from a low-current, high-voltage power company can be generated as a zero-cross signal and input to the dimmer. For this reason, it is possible to detect an accurate Xerox signal from an AC voltage that is not affected by distortion generated on the load side, and it is possible to realize light control by more stable phase control.

  In this embodiment, as compared with the first and second embodiments, more stable dimming can be realized because the influence of the distortion on the secondary side of the step-down transformer is further suppressed.

  In the third embodiment, an example using single-phase two-wire transmission / distribution was given, but a zero-cross of an AC voltage before voltage conversion to a low voltage was detected even in a three-phase four-wire system. It is applicable to the case and has the same effect.

  As shown in FIG. 13, when a large number of in-phase dimmers are turned on at the same ignition timing particularly when the lamp is cold, the inrush current flows and the power supply is distorted, so that the zero-cross signal detection may shift. 13A shows the voltage waveform on the primary side of the illumination transformer, and FIG. 13B shows the case where the ignition timing of the R phase dimming output overlaps the zero point of the S phase. ) Shows that the zero point of the secondary side S-phase power supply of the illumination transformer is distorted and the S-phase zero cross signal is shifted as a result.

  Therefore, even when using a three-phase four-wire commercial power supply with excellent characteristics supplied from a low-current, high-voltage power company, an accurate Xerox signal can be obtained from an AC voltage that is not affected by the distortion generated on the load side. By detecting and transmitting wirelessly, it becomes possible to realize light control by more stable phase control.

  The dimmer in each of the above embodiments uses a thyristor connected in parallel in the reverse direction, but the output from the controller switches the AC voltage by changing the pulse width based on the dimming signal. Dimming by PWM control may be used. Further, although the thyristor is used as the switching element of the dimmer, other switching elements such as a triac or FET may be used.

  The light source may be an LED, a discharge lamp, an organic EL, or the like in addition to the light bulb.

  Although several embodiments have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, combinations, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

11 AC power supply 12 Step-down transformer 12a Primary side 12b Secondary side 13 Dimming control unit 14 Zero cross detector 15 Transmitter 18 Receiver 19 Controller 20 Dimming table 211 to 21n

Claims (2)

A zero-cross detector that detects the zero-cross of the AC power supply voltage and generates a zero-cross signal;
In a lighting system comprising: a dimming control unit that obtains a dimming voltage of a light source by performing phase control of the AC power supply voltage based on the timing of the locross signal and a dimming signal;
The zero cross signal is input to the dimming control unit by radio.   2. The illumination system according to claim 1, wherein the detection point of the zero crossing of the AC power supply voltage is a primary side or a secondary side of a transformer that converts a high voltage into a low voltage for lighting a light source.

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