JPH027392A - Dimming device - Google Patents

Abstract

PURPOSE:To perform the phase angle control without applying of a voltage having unnecessarily high peak value to a load and aim at the long life of the load by providing a switching element for the phase angle control, corresponding separately to each ac voltage from ac supply. CONSTITUTION:Control means E1-En perform the phase angle control of switching elements C1-Cn corresponding to an ac voltage Va having a relatively low peak value, with the power electrically energizing load R1-Rn becomes larger. When a continuity angle of the ac voltage Va having the relatively low peak value reachs a half-cycle of the ac voltage, the switching elements C1-Cn corresponding to the ac voltage Va having the relatively low peak value are held in continuity condition, and a control signal is output so as to perform the phase angle control of switching elements D1-Dn corresponding to an ac voltage Vb having a relatively high peak value. Consequently, when the power given to the loads R1-Rn is small, the ac voltage having the relatively low peak value is controlled about phase angle to be given to the loads. The long life of the load can be thus aimed without giving unnecessarily the ac voltage having the relatively high peak value to the loads.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a light control device suitable for use as lighting in, for example, photo studios and stages.

Conventional technology When the color temperature of a lighting load that lights a photo studio or a stage is low, in order to make the color temperature of this lighting load higher, the voltage must be higher than the rated voltage of the lighting load. voltage must be applied to the lighting load. In such a case, the light control device 1 shown in FIG.
is used.

The light control device 1 includes a transformer 3, a switch SWI, and switching elements A1 such as a thyristor or a triac.
An (when collectively referred to as "switching element Ai"), trigger signal generation circuits B1 to Bn (when collectively referred to as "trigger signal generation circuit Bi"), and lighting loads M1 to Mn (when collectively referred to as "lighting load MiJ"). ).

An AC voltage of 100 V (hereinafter, AC voltage represents an actual value) from the commercial AC power supply 2 is applied to the transformer 3 . On the output side of the transformer 3, there are a tap 10 and a tap 10.
A tap 11 from which an AC voltage of 100V is derived for the tap 10, and a tap 12 from which an AC voltage of 120V is derived from the tap 10 are provided. Tap 10 is connected to line 11, and tap 11 and tap 12 are connected to switch SW1.

The switch SW1 switches between the AC voltage from the tap 11 and the AC voltage from the tap 12, and outputs the AC voltage to the line 12. Therefore, line 12 has 1 with respect to line 11.
The AC voltage of 00V and the AC voltage of 120V are switched and derived.

One terminal of the lighting loads M1 to Mn is connected in parallel to the line 11. Furthermore, switching elements A1 to An are connected in parallel to the line 12. The outputs from the switching elements A1 to An are respectively given to the other terminals of the lighting loads M1 to Mn. This lighting load M1~
The rated voltage of Mn is, for example, 100■.

Trigger signal generation circuits 81 to Bn output trigger signals, which will be described later, to switching elements A1 to An, respectively, in synchronization with the AC voltage derived between line 11 and line 12. FIG. 7 is a waveform diagram showing an example of the waveform of one cycle of the AC voltage derived to the lighting load Mi. The trigger signal generation circuit Bi outputs a trigger signal having a pulse that rises at time t1, for example, and whose period is W1, which is 1/2 of the period of the AC voltage derived between lines 11 and 12. As a result, the switching element Ai controls the phase angle of the AC voltage between the lines 11 and 12 at the conduction angle W2, and the AC voltage having the waveform shown in FIG. 7 is applied to the lighting load Mi.

FIG. 8 is a graph showing the relationship between the conduction angle W2 and the effective value of the AC voltage applied to the lighting load Mi. By operating the trigger signal generation circuit Bi, the conduction angle W2 can be set to 0.
It can be set to vary between 180 degrees and 180 degrees. In FIG. 8, a line 13 shows a case where an AC voltage of 100 V is derived from the line 12, and a line 14 shows a case where an AC voltage of 120 V is derived from the line 12.

In such a light control device 1, when it is desired to set the color temperature of the lighting load to a desired value corresponding to the effective value of the AC voltage applied to the lighting loads M1 to Mn from 0 to 100, switch SW1 is used. is set so that an AC voltage of 1·OOV is derived from the line 11, and the trigger signal generation circuit Bi is operated. Phase angle control is performed based on this operation, and by changing the effective value of the AC voltage applied to the lighting load Mi, it is possible to control the lighting load Mi to have a desired color temperature.

If you want to further increase the color temperature of the lighting load Mi, set the switch SWI so that an AC voltage of 120V is derived from the line 12, so that an AC voltage of up to 120V is applied to the lighting load Mi. Can be set.

Problems to be Solved by the Invention In the above-described light control device 1, the line 12 is
When the setting is such that an AC voltage of 120V is derived at 10V, the AC voltage applied to the lighting load Mi is
The rated voltage of the lighting load Mi, which causes the peak value of the AC voltage applied to the lighting load to be higher than the AC voltage in the case where an AC voltage of 100 cm is derived to the line 12, even if it is 0V or less. is 100V, and if a voltage higher than this rated voltage is applied, the life of the lighting load Mi will be significantly shortened. If the switch SWI is set to derive an AC voltage of 120V to the line 12, an AC voltage of 0 to 120V can be set and supplied to the lighting load Mi by phase angle control, and therefore the switch S
W1 is often set so that an AC voltage of 120 cm is derived from the line 12. Therefore, in the light control device 1, the life of the lighting load Mi is shortened, and the lighting load Mi must be replaced frequently. There is a problem that it disappears.

An object of the present invention is to control the phase angle of the AC voltage applied to the load without applying an unduly high peak value voltage to the load, extend the life of the load, and reduce the frequency of the load. It is an object of the present invention to provide a light control device that prevents replacement and improves convenience.

Means for Solving the Problems The present invention provides an AC power source that synchronously derives AC voltages having at least two different peak values, and an AC power source that is provided individually corresponding to each AC voltage from the AC power source. A switching element for phase angle control is interposed between the power source and the load, and as the power energizing the load increases, the phase angle control of the switching element corresponding to the relatively low peak value of AC voltage is performed. However, when the conduction angle of the AC voltage with the relatively low peak value reaches a half cycle of the AC power supply, the switching element corresponding to the AC voltage with the relatively low peak value is kept in a conductive state, and the relatively and control means for controlling the phase angle of a switching element corresponding to an AC voltage having a high peak value.

Operation According to the present invention, AC voltages having at least two different peak values are derived from the AC power source in the same phase.

This alternating current voltage is applied to each switching element individually corresponding to each alternating voltage. The switching element controls the phase angle of the input AC voltage based on the control signal from the control means, and applies it to the load.

The control means controls the phase angle of the switching element corresponding to the AC voltage having a relatively low peak value as the power energizing the load increases, and the conduction angle of the AC voltage having the relatively low peak value decreases. When reaches a half cycle of the AC voltage, the switching elements corresponding to the relatively low peak value AC voltage are kept conductive, and the switching elements corresponding to the relatively high peak value AC voltage are kept conductive. A control signal is output to perform phase angle control.

Therefore, when the power given to the load is small, an AC voltage with a relatively low peak value is given to the load by controlling the phase angle, so that an AC voltage with a relatively high peak value is not given to the load unnecessarily. It is possible to control the effective value of the voltage applied to the load.

Embodiment FIG. 1 is a block diagram showing the configuration of a light control device 11 according to an embodiment of the present invention. The light control device 11 is used for lighting a photo studio, a stage, etc., and is connected to a transformer 13.
, trigger signal generation/main circuits E1 to En as control means, switching elements C1 to Cn, DI to Dn, and lighting loads R1 to Rn as loads. below,
When collectively referring to only n lighting loads that individually correspond to the lighting loads R1 to Rn, a reference numeral with an "i" added to the same alphabet is used.

For example, an AC voltage of 100 μm is generated from the commercial AC power supply 12, and this AC voltage is applied to the input side of the transformer 13. There are taps 20, 21.2 on the output side of the transformer 13.
2 is provided, and an AC voltage Va of 100 cm is derived from the tap 21 with respect to the tap 20. Also tap 2
2 has the same phase as the AC voltage Va derived to the tap 21, and an AC voltage vb of 120V is derived to the tap 20. Taps 20, 21, 22 are line 15°1
6 and 17, respectively. Therefore, with the line 15 as a ground line, an AC voltage Va of 100 cm is derived from the line 16, and an AC voltage vb of 120 cm is derived from the line 17.

The transformer 13 and the commercial AC power supply 12 constitute an AC power supply.

One terminal of each of the lighting loads R1 to Rn is connected to the line 15, respectively. The rated voltage of the lighting loads R1 to Rn is, for example, 100 cm. The other terminals of the lighting loads R1 to Rn are connected to connection points P1 to Pn, respectively. These connection points P1 to Pn are connected to the switching element C1
-Cr+ to the line 16, respectively, and via switching elements D1 to Dn to the line 17, respectively. These switching elements C1 to Cn.

D1 to Dn are realized by semiconductor switching elements such as thyristors, diacs, or triacs.

The switching elements C1 to Cn and Di to Dn receive trigger signals Scl from trigger signal generation circuits E1 to En, which will be described later.
~Scn and Sdl~Sdn control their conduction/blocking states, respectively.

The trigger signal generation circuit Ei (i=1.2..., n) includes, for example, comparators Fi, Gi, a differential amplifier Ii, an amplifier Hi, a phase control signal generation circuit Ji, and a dimming level signal. It is configured to include a generation circuit Ki and a reference signal generation circuit Li. This trigger signal generation circuit Ei derives trigger signals Sci, Sdi, which are pulse signals having a period of 1/2 of the period of the AC voltage Va derived to the line 16, to the switching elements Ci, Di, thereby causing the illumination load The phase angle of the AC voltage Vi that energizes Ri is controlled.

The phase control signal Set output from the phase control signal generation circuit Ji is applied to the inverting input terminals of the comparators Fi and Gi, respectively. The dimming level signal Sfi from the dimming level signal generation circuit Ki is applied to the non-inverting input terminal of the comparator Fi, and is also applied to the differential amplifier 1i. Therefore, the comparator Fi outputs the l-rigger signal Sci which becomes high level when the phase control signal Sei is lower than the dimming level signal Sfi.

A reference signal generation circuit L is connected to the other terminal of the differential amplifier Ii.
A reference signal, for example a DC voltage of -10 V, from i is applied. In the differential amplifier It, the dimming level signal Sf
i and the reference signal of -10■ are added, that is, the voltage of the dimming level signal Sfi is subtracted by 10V, and the result is output to the amplifier Hi.

The amplifier Hi amplifies the input signal to a voltage level five times higher and outputs it as a dimming level signal Sgi to the non-inverting input terminal of the comparator Gi. Therefore, the comparator Gi outputs the trigger signal Sdi which becomes high level when the voltage of the phase control signal Sei' is lower than the voltage of the dimming level signal Sgi.

2 and 3 are waveform diagrams for explaining the operation of the light control device 11, and the operation will be explained below with reference to these figures. The operation when operating the dimming level signal generation circuit Ki so that the voltage of the dimming level signal Sfi is 0 to 10V and lighting the lighting load with an AC voltage of 0 to 100V is shown in Fig. 2. The one-phase control signal Sei is shown by line 18 in FIG. 2(2). Also, the dimming level signal S
fi is as shown by line 19 in FIG. 2(2). Therefore, from the comparator Fi, the phase control signal S
A time t2.et when the voltage of the dimming level signal Sfi becomes lower than the voltage of the dimming level signal Sfi. A trigger signal Sci rising at t4 is derived. This trigger signal Sci is shown in FIG. 2(3).

At this time, since the dimming level signal Sfi has a voltage of 10<1> or less, the dimming level signal Sgi having a negative voltage is applied from the operational amplifier 1i to the comparator Gi via the amplifier Hi. Therefore, the trigger signal Sdi output from the comparator Gi is constantly at a low level as shown in FIG. 2 (4). Since the trigger signal Sdi is constantly at a low level, the switching element Di maintains the cut-off state.

Further, a trigger signal Sci shown in FIG. 2(3) is applied to the switching element Ci as a control signal. The switching element Ci has a line 16 shown in FIG. 2(1).
An alternating current voltage Va of 100V derived from . In Fig. 2 (1), the virtual line is the AC voltage v of 120■
Therefore, switching element Ci is activated at time t2.b when trigger signal Sci rises. It becomes conductive at t4, and becomes cut off at time t3 when the polarity of the AC voltage Va shown in FIG. 2 (1) is reversed. Therefore, the waveform of the voltage Vi applied to the lighting load Ri is such that the alternating current voltage Va derived to the line 16 has a conduction angle T1, as shown in FIG. 2 (5).
The phase angle is controlled by .

In this way, in this embodiment, when it is desired to light up the lighting load Ri at a color temperature corresponding to the case where the AC voltage applied to the lighting load Ri is 0 to 100cm, the light is led out to the line 16. An AC voltage i obtained by controlling the phase angle of an AC voltage Va of 100 cm is applied to the lighting load Ri to light the lighting load Ri at a desired color temperature.

If you want to further increase the color temperature of the lighting load Ri in order to illuminate the illuminated object in a natural color, the voltage level of the dimming level signal Sfi can be adjusted by operating the dimming level signal generation circuit Ki. is higher than 10V. The dimming level signal Sfi at this time is shown by the line 111 in FIG. 3(2). Since the maximum voltage level of the phase control signal Set indicated by the line 110 is 10■, the trigger signal Sci output from the comparator Fi is as shown in FIG.
As shown, it is always at a high level.

The dimming level signal Sgi, which is obtained by subtracting 1o■ from the dimming level signal Sfi and amplifying it five times, is the line 1 in Fig. 3 (2).
12. Therefore, the trigger signal Sdi output from the comparator Gi is generated at time t5 when the voltage of the phase control signal Sei becomes lower than the voltage of the dimming level signal Sgi, as shown in FIG. 3(4). It rises at t7.

The switching element Di operates at time t5. when the trigger signal Sdi rises. At t7, it becomes conductive, and at the time t when the polarity of the AC voltage vb of 120 cm shown in FIG. 3(1) is reversed.
6, the state is cut off.

In Fig. 3 (1), the virtual line is the AC voltage Va of 100V.
Therefore, as shown in FIG. 3(5), the lighting load Ri has a period of conduction T4. of the switching element Di. At T6, 120 shown in Figure 3 (1)
Period T3. during which the AC voltage vb of (2) is applied as the AC voltage Vi and the switching element D1 is in the cut-off state. T
5, an AC voltage Va of 100V shown in FIG. 2(1) is applied as an AC voltage Vi. In addition, period T
4. Although a high-level trigger signal Sci is derived to the switching element Ci at T6, at time t
5. At t7, the direction of the current flowing through the switching element Ci is reversed, so the switching element Ci enters the cut-off state.

FIG. 4 is a waveform diagram of the AC voltage ■i applied to the lighting load Ri corresponding to each voltage level of the dimming level signal Sfi. In FIG. 4, a line 113 indicated by a virtual line indicates the waveform of the AC voltage Va derived from the line 16, and a line 114 indicates the line ! FIGS. 4(1) to 4(3), which show the waveforms of the AC voltage vb derived in FIG. The waveforms of voltage Vi are shown respectively.

In this way, when the dimming level signal is O to IOV, the switching element Di is in the cutoff state, and the switching element Ci controls the phase angle of the AC voltage Va of 100μ and outputs it to the lighting load Ri. .

4th cl! I(4) and FIG. 4(5) respectively show the waveforms of the AC voltage Vi applied to the lighting load Ri when the voltages of the ill light level signal Sfi are 11V and 12V. The voltage of the dimming level signal Sfi is IO
When the voltage is higher than V, the phase angle of the AC voltage vb of 120V is controlled, and during the period when this AC voltage vb of 120V is not applied to the lighting load Ri, the AC voltage Va of 100V is applied to the lighting through the switching element Ci. The load Ri is derived.

Therefore, as shown in FIG.
AC voltage Vi having an effective value corresponding to the voltage level of i
is applied to the lighting load Ri, and this lighting load R is applied at the desired color temperature.
i can be lit.

In this way, in this embodiment, for example, the lighting load Ri
In order to further increase the color temperature of the lighting load Ri when the rated voltage of the lighting load Ri is 100 .ANG., an AC voltage of 100 .ANG. or more can be supplied to the lighting load Ri. Moreover, only when applying an AC voltage higher than the rated voltage to the lighting load Ri, a voltage of the peak value of the AC voltage vb of 120 cm is applied to the lighting load Ri, so that the voltage of the peak value is applied to the lighting load Ri. The number of times that is applied can be reduced. Therefore, it is possible to prevent the life of the lighting load Ri from being extremely shortened.

In this embodiment, the rated voltage of the lighting load Ri is 100
Although the configuration is such that the color temperature of the lighting load Ri is adjusted by controlling the phase angle of AC voltages of 100 and 120V and deriving them to the lighting load Ri, these values are just examples, and other Although the AC voltage from the AC power supply has been explained in the case of two types, AC voltage Va and AC voltage vb, it is possible to control the phase angle of AC voltage having three or more different peak values. It can also be configured to turn on the lighting load.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, as described in detail, it is possible to control the power applied to the load without increasing the peak value of the AC voltage as much as possible. For example, if you want to energize a load with a rated voltage of This can be reduced compared to what has been described in connection with the prior art. Therefore, it is possible to prevent the life of the load from being extremely shortened due to the application of a peak value of AC voltage that is higher than the rated voltage. Therefore, the desired AC voltage can be supplied to the load, and there is no need to frequently replace the load, which greatly improves convenience.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 shows that the voltage of the dimming level signal Sfi of the dimming device 11 is I
FIG. 3 is a waveform diagram for explaining the operation when the voltage is below OV, and the voltage of the dimming level signal Sfi of the dimming device 11 is
4 is a waveform diagram showing the voltage Vi applied to the lighting load Ri at each voltage level of the dimming level signal Sfi, and FIG. 5 is a waveform diagram showing the voltage Vi applied to the lighting load Ri at each voltage level of the dimming level signal Sfi. Graph 6 shows the relationship between the voltage of the signal Sfi and the effective value of the AC voltage Vi applied to the lighting load Ri.
The figure is a block diagram showing the configuration of a conventional light control device 1,
FIG. 7 is a waveform diagram showing an example of the waveform of the AC voltage applied to the lighting load Mi of the dimmer 1, and FIG. 8 is a waveform diagram showing the conduction angle W2 in the dimmer 1 and the AC voltage applied to the lighting load Mi. It is a graph showing the relationship between the effective value of 11... Light control device, 12... Commercial AC power supply, 13.
...Transformer, e5. l 6. e 7-5in, Cl
~Crt. D1~D1...Switching element, E1~Err・
...Trigger signal generation circuit, R1 to Rr+-...Lighting load, Va. vb...AC voltage Voltage level signal Sfi voltage level 1 Continuity PIW2 (degrees)

Claims (1)

[Scope of Claims] An AC power source that synchronously derives AC voltages having at least two different peak values; and an AC power source that is provided individually corresponding to each AC voltage from the AC power source, and that connects the AC power source and a load. As the power energizing the load increases, the switching element for controlling the phase angle interposed between the switching element and the switching element corresponding to the relatively low peak value of AC voltage is controlled, and the relative When the conduction angle of the AC voltage with a relatively low peak value reaches a half cycle of the AC power supply, the switching element corresponding to the AC voltage with a relatively low peak value is kept in a conductive state, and the conduction angle of the AC voltage with a relatively high peak value is maintained. A light control device comprising: control means for controlling the phase angle of a switching element corresponding to an alternating current voltage.