JPS5866294A - Device for dimming discharge lamp - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a discharge lamp dimmer device in which a discharge lamp is driven by an inverter, and an output from an AC power source is supplied to the inverter after being phase-controlled by a phase control circuit.

FIG. 1 is a block diagram of the prior art. Discharge lamp 1#'
i. It has a discharge electrode 2.3, and high frequency power is supplied to the discharge lamp 1 from an inverter 4. The inverter 4 includes a transformer 5, a capacitor 6,
Transistor 7.8, choke coil 9, full wave rectifier circuit 10 and circuit 19.2 for controlling transistor 7.8
Contains 0. A sine wave output from a commercial AC power source 11 is phase-controlled by a phase control circuit 12 and is applied to the inverter 4 from a line 13.14. Phase control circuit 12H
1) It includes a TRIAC 15 and a pulse generation circuit 17 that generates a control signal for phase control at the TRIAC 150 control terminal 16. Phase control circuit 12 and inverter 4
In the same line 13, there is a switch 18 installed on the wall of a building and operated.

The open AC power supply 11 supplies the phase control circuit 12 with power having a voltage waveform shown in FIG. 2(1).

The inverter 4 applies a high frequency voltage shown in FIG. 2 (2) and FIG. 2 (3) between the discharge electrodes 2j3 of the discharge lamp 1. The voltage waveform in FIG. 2 (2) is the voltage waveform when the illumination lamp 1 is dimmed so that it lights up the brightest, and the angle θ1t/
For example, it is 30 degrees. That is, the try 15 of the phase control circuit 12 is cut off between 0 degrees and 30 degrees, and conductive between 30 degrees and 180 degrees in each half cycle of the commercial AC power supply 11. In the voltage waveform of Figure 2 (3), θ2
= 120°, and the discharge lamp 1 is illuminated W4 darker than the lighting state shown in FIG. 2 (2). In each half cycle of the 15 triac commercial AC power supply 11, it is cut off between 0 degrees and 120 degrees, and conductive between 120 degrees and 180 degrees.

FIG. 3 is a graph showing the enclosure of the angle θ cut off by the triac 15 and the dimming ratio 0D.

Angle θ1 in FIG. 2 (2) and FIG. 2 (3). θ
2 is collectively expressed as an angle θ. Dimming ratio D is discharge lamp 1
is the percentage of the light output when the light output in the brightest dimming state is set as 100. Arrow l! This is the case when the light is dimmed according to the curve #-i shown by the solid line No. 1 in FIG. It can be seen that as the angle θ cut off by the triac 15 increases, the dimming ratio #D decreases.

The angle θ is between 0 degrees and 90 degrees for each half cycle of the commercial AC power supply 11.
When the voltage is within the range of 100°C, the maximum value 1 of the output voltage of the inverter 4 is applied to the discharge lamp IK, as shown in FIG. 2 (2). On the other hand, when the angle θ is selected in the range of 90 degrees to 180 degrees, a voltage v2 smaller than the maximum value v1 is applied to the discharge lamp IK from the inverter 4, as shown by gg2 in FIG. 13). Therefore, if Vl is set as the discharge starting voltage of the discharge lamp 1, a voltage sufficient to start the discharge will not be applied to the discharge lamp 1 when the angle θ is in the range of 90 degrees to 180 degrees. In order to start discharging the discharge lamp 1 even when the angle θ is selected in the range of 90 degrees to 180 degrees, the maximum value of the output voltage of the inverter 4 at the maximum value of the angle θ adopted for dimming, e.g. In FIG. 2(3), the maximum value v2 must be determined to be equal to or higher than the discharge starting voltage of the discharge lamp 1. If you do that, the angle θ will be between 0 degrees and 9 degrees.
If the temperature is selected within the range of 0 degrees, an unnecessarily high voltage will be applied to the discharge lamp 1 by the inverter 4. As a result, the life of the discharge lamp 1 is shortened, and the transformer 5 needs to have an unnecessarily high withstand voltage, so it becomes large.
Moreover, power loss increases, and furthermore, the socket for the discharge lamp 1 needs to have a high withstand voltage.

In order to solve this problem, the angle β should be between 90 degrees and 1
When a range of 80 degrees is selected, a voltage as shown in FIG. 2 (2) is applied only when the discharge lamp 1 is started in response to power-on, and the maximum value v of the voltage at the angle θ = 90 degrees is applied.
It is also conceivable to improve the phase control circuit 12 so that 1 is given to the discharge lamp l. According to such a configuration,
If the switch 18 is interposed between the phase control circuit 15 and the inverter 4, such an improvement of the phase control circuit 12 becomes meaningless.

An object of the present invention is to provide a discharge lamp that can start discharging even when the dimming ratio of the discharge lamp is controlled to be small, and that can further reduce the voltage applied to the discharge lamp as low as possible. An object of the present invention is to provide a light control device.

Another object of the present invention is to provide a discharge lamp that can start the discharge lamp without the need to specially change the circuit configuration even when a switch is interposed between the phase control circuit and the inverter. An object of the present invention is to provide a light control device.

Figure gg4 is an electrical circuit diagram of an embodiment of the present invention.

Corresponding parts of the prior art described in connection with FIG. 1 are given the same reference numerals. The discharge lamp 1 has discharge electrodes 2.3 and is powered by an output from an inverter 4. It includes a circuit 19.20 for controlling an inverter 4Vi, a transformer 5, a capacitor 6, a transistor 7.8, a choke coil 9, a full-wave rectifier circuit 10, and a transistor 7.8. A sine wave output from a commercial AC power source 11 is applied to the inverter 4 from a phase/phase control circuit 12 via lines 13 and 14. The phase control circuit 12 includes a triac 15 and a pulse generation circuit 17 that provides a control signal to a control terminal 16 of the triac 15. A line 13 between the phase control circuit 12 and the inverter 4 is interposed with a switch 18 that is installed on a wall of a building and is operated.

According to the present invention, a triac 22 as a switching element is connected between the discharge electrodes 2 and 3. The output from the aftermath rectifier circuit 10 included in the inverter 4 is
It is applied to a control circuit 23 for deriving a signal for controlling the triac 22. This control circuit 23 includes
A series circuit 26 consisting of a capacitor 24 and a resistor 25 is provided.

Lines 27 and 28 are connected via transistor 29.
A series circuit consisting of a capacitor 3 (1, 31) is connected to the capacitor 30. A resistor 32 for discharging is connected in parallel to the capacitor 30. A connection point 33 between the capacitors 30, 31 is connected to a diode 34 and a silicon pirate switch ( Abbreviated as S B S ), 35 are connected. Line 27 .
28 also includes a resistor 36° 37 and a light emitting diode 3.
8 are connected in series, and the connection point 3 of resistor 36.37
A silicon pirate switch 35 is connected to 9. A phototransistor 42 that receives light from the light emitting diode 38 is connected in series to the transformer 40 .

The output from the transformer 40 is given to a control terminal 41 of the triac 22.

In the phase control circuit 12, the pulse generation circuit 17 generates a control signal so that the triac 15 becomes conductive at a time when the output voltage of the commercial AC power supply 11 reaches 90 degrees from zero degrees.

Figure 5 T'l) and the line 27 from the full wave rectifier circuit 10.
The waveform of the voltage derived between 28° and 28° is shown. The 15 triacs are turned on at an angle θ3 during each half cycle of the output voltage of the commercial AC power source 11 from zero degrees to 90 degrees. At the connection point 42 of the series circuit 26 consisting of the capacitor 24 and the resistor 25, a capacitor ? 24, a differential waveform is generated. As a result, the transistor 29 becomes zero for a moment. This instantaneous conduction of transistor 29 charges capacitor 31 to a divided voltage determined by the capacitance of capacitors 30 and 31;
1 terminal voltage ■3 is maintained.

vJ5 diagram +2) Vc, Vi, capacitor f311) Output voltage V317) Waveforms are shown. On the other hand, resistance 36.3
At the connection point 39 of 7, the voltage shown in @5 figure (2) ■4
appears. A period Vi during which the discharge lamp 1 is discharging is shown in FIG. 5(3). In the range v3≦■4,
Due to the action of the diode 34, the silicon lateral switch 35 remains cut off. V3>V4, and the difference (V3-V4) becomes the pressure VBO of the silicon lateral switch 35. When the angle αlK is reached, the silicon lateral switch 3
5 is conductive. Therefore, the discharge current of the capacitor 31 instantaneously flows from the connection point 33 to the diode 34, the silicon pirate switch 35, the connection point 39, the resistor 37, and the light emitting diode 38. As a result, the light emitting diode 38 lights up and the phototransistor 42 becomes conductive. Therefore, from the transformer 40 to the control terminal 41 of the triac 22
A control signal is applied to the triac 22, and the triac 22 becomes conductive as shown in FIG. 5(4) in the range of angle α1 to 180 degrees. Therefore, the discharge lamp 1 is turned off after the angle α1. In this way, the discharge lamp 1 is lit in the range of angle (α1-03).

In the phase control circuit 12, the triac 15 is connected to the commercial AC power source 11 at an angle θ4 near 90 degrees (however, θ4>θ3
) is assumed to be conductive. In this case VC#-
i, from the aftermath rectifier circuit 10 to line 27.28, No. 6
The voltage waveform shown in Fig. 3 is obtained.Capacitor 31
, that is, the voltage v3 at the connection Q33 and the voltage v4 at the connection point 39 between the resistors 36 and 37 are as shown in FIG. 6(2). The angle α2 at which the triac 22 conducts is faster than in the case of FIG.

Therefore, for one discharge lamp, the angle θ4 is as shown in Figure 6 (3).
The triac 22 is energized for a relatively rectangular period of time between the time of the angle α2 and the time of the angle α2.
Between 0 degrees, conduction is established as shown in Figure 6'(4). In this way, the phase control cycle lol! The conducting angle θ3 of the triac 15 included in r12. As θ4 approaches the zero side of each half cycle of the output voltage of the commercial AC power supply 11, the triac 22 becomes conductive at a later time. J: An example of the relationship between the dimming ratio 0D and the phase control angle θ according to the above configuration is shown in the third example.
In the figure, reference numeral 12 is indicated by a broken line with l=t.

Instead of the triacs 15 and 22, switching elements having other control terminals, such as triacs, may be used. Inverter 4 may have other configurations.

As described above, according to the present invention, the phase control circuit is configured to conduct at the time when the output voltage of each half cycle of the AC power supply reaches 90 degrees from zero degrees.
A voltage corresponding to the maximum output voltage of the AC power source is always applied to the discharge lamp via the inverter. Therefore, it is only necessary to select the maximum value as the voltage for starting discharge, and there is no need to set the voltage applied to the discharge lamp from the inverter unnecessarily high during dimming. Since an unnecessarily high voltage is not applied to the discharge lamp, the life of the discharge lamp is extended, and the withstand voltage of components related to the discharge lamp can be reduced.

In addition, a switching element is connected between the discharge electrodes 1c of the discharge lamp, and this switching element is turned on at a later time in the range of 90 degrees to 18.0 degrees as the conduction time of the phase control circuit approaches the zero degree side. Even if a switch for controlling the lighting and extinguishing of the discharge lamp is interposed between the phase control circuit and the inverter, there is no need to change the configuration of the phase control circuit and the inverter, and this method is advantageous based on the prior art described above. It does not pose the problems mentioned and is therefore easy to construct.

[Brief explanation of the drawing]

! Fig. 1 is a block diagram of the prior art, Fig. 2 is a voltage waveform diagram for explaining the operation of the prior art shown in Fig. 1, and Fig. 3 shows the relationship between the angle θ at which the triac 15 cuts off and the dimming ratio D. A diagram showing the relationship, FIG. 4 is an electric circuit diagram of an embodiment of the present invention,
FIGS. 5 and 6 are waveform diagrams for explaining the operation of the embodiment shown in FIG. wJ4. DESCRIPTION OF SYMBOLS 1... Discharge lamp, 2, 3... Discharge electrode, 4... Inno(-ta), 11... Commercial AC power supply, 12... Phase control circuit, 15... Triac, 18...・Switch, 22...Triac agent Patent attorney Kei Nishi Part 5 Figure 6 (4) m (4) mU procedural amendment April 5, 1981 Patent application for indication of case 11, 1982- 165276 2. Name of the invention: Discharge lamp dimmer device 3. Relationship with the person making the amendment: Applicant address: 11148 Oaza Kadoma, Kadoma City, Osaka Prefecture Name (5)
83) Matsushita Electric Works Co., Ltd. Representative: Iku Kobayashi 4, Agent address: Shinkosan Building 6, 1-13-38 Nishihonmachi, Nishi-ku, Osaka City, Detailed description of the invention in the specification subject to amendment and drawings 7, Amendment Contents + 1) In the 6th line of page 3 of specification 4i, "illumination lamp 1" is corrected to "discharge lamp 1." . (2) In the specification 4F, page 5, line 20, "phase control circuit 15" is corrected to "phase control circuit vIi12J". ", W1 is stopped at "43". (4) In the 11th line of page 11 in the specification section, the word "thyristor" has been corrected to "transistor." (5) Correct Figure 4 of the drawings as shown in the paper. that's all

Claims (1)

[Claims] In a discharge lamp dimmer device in which an output from an AC power supply via a phase control circuit is applied to the discharge lamp via an inverter, the phase control circuit is configured to control the output voltage of the AC power supply for each half cycle. It is configured to become conductive at a time between zero and 90 degrees, has a control terminal and is connected between the discharge electrodes of the discharge lamp, and a switching element connected between the discharge electrodes of the discharge lamp. A signal is applied to the control terminal of the switching element at a time between exceeding 90 degrees and reaching 180 degrees in each half cycle of , causing the switching element to conduct, and the conduction time of the phase control circuit is equal to the output voltage of the phase control circuit. A discharge lamp dimmer comprising: a switching control circuit that turns on a switching element at a later time as the temperature approaches zero.