JPH04298999A - Discharge lamp lighting device - Google Patents

Abstract

PURPOSE:To stabilize a discharge so as to prevent lighting failure by lighting a discharge lamp with full light when an ambient temperature of the discharge lamp is lower than an ordinary temperature. CONSTITUTION:When a main switch 8 and a dimmer switch 10 are both closed, a discharge lamp 6 is dimmably started lighted in the case of an ambient temperature of the discharge lamp 6 higher than an ordinary temperature. In the case of the ambient temperature of the discharge lamp 6 lower than the ordinary temperature, forward voltage between a base and an emitter of a transistor 15 is high generated, so that a collector-emitter current of the transistor 15 is reduced to lower an intermediate potential V1 between resistors 18, 19. This low potential is inversion-amplified to a high potential by an operational amplifier 22 to turn on an FET23. By turning on the FET23, an output frequency of an inverter 5 is decreased, and an output of the inverter 5 is increased to start the discharge lamp 6 lighted with full light. Accordingly, a discharge is stabilized to prevent lighting failure.

Description

[Detailed description of the invention]

[Object of the invention]

0002

[Industrial Application Field] This invention relates to a discharge lamp lighting device for lighting discharge lamps such as fluorescent lamps in a dimmable manner, and in particular, the present invention relates to a discharge lamp lighting device that lights a discharge lamp such as a fluorescent lamp in a dimmable manner. The present invention relates to a discharge lamp lighting device that is provided with a starting means that switches automatically.

0003

2. Description of the Related Art Conventionally, starting methods for this type of discharge lamp lighting device include an all-light starting method and a dimming starting method.

[0004] The all-light starting method is a method in which a discharge lamp such as a fluorescent lamp is turned on with full light when starting, but it has the inconvenience of not being able to dim the lamp when starting.

On the other hand, the dimming starting method allows the discharge lamp to be turned on in a dimmable manner from the time it is started, and therefore has the convenience of being able to dim the discharge lamp from the time it is started.

[0006]

[Problems to be Solved by the Invention] However, in such a conventional dimming start type discharge lamp lighting device, when the ambient temperature of the discharge lamp is low, the mercury vapor pressure inside the tube decreases, and argon, etc. Because the pressure ratio with the sealed gas pressure changes,
In some cases, there is a problem that the discharge lamp goes out.

[0007] The present invention was made in consideration of the above circumstances, and its purpose is to provide a control system that can start the discharge lamp at full light when the ambient temperature of the discharge lamp is low, thereby preventing the discharge lamp from going out. An object of the present invention is to provide a discharge lamp lighting device that can control light. [Structure of the invention]

[0008]

[Means for Solving the Problems] In order to solve the above problems, the present invention is constructed as follows.

In other words, the present invention provides a circuit for lighting a discharge lamp, a dimmer circuit for dimming the lighting of the discharge lamp by turning on a dimmer switch, and an interposed device between the dimmer switch and the dimmer circuit. and a transistor that changes a voltage signal to the dimmer circuit depending on whether the dimmer switch is turned on or off;
When the ambient temperature of the discharge lamp is lower than room temperature when the dimmer switch is turned on, the temperature characteristics of the transistor are used to control the voltage signal to the dimmer circuit until the temperature reaches room temperature, so that the discharge lamp is completely turned off. It has a starting means that starts and lights up with light.

0010

[Operation] When starting the discharge lamp, if the ambient temperature is lower than normal temperature, the discharge lamp is turned on at full brightness by the starting means.

[0011] After the discharge lamp is started with full light and the ambient temperature of the lamp reaches room temperature, it is switched to dim lighting.

Therefore, according to the present invention, when the ambient temperature of the discharge lamp is lower than room temperature, the discharge lamp is turned on with full brightness, so that the discharge lamp can be stabilized and the discharge lamp can be prevented from going out. Can be done.

Furthermore, since the discharge lamp is rapidly heated and stabilized by full-light lighting, the dimming lighting can be started earlier.

Furthermore, when the ambient temperature of the discharge lamp is higher than room temperature, the discharge lamp can be started by dimming, which is highly convenient.

[0015]

Embodiments Hereinafter, embodiments of the present invention will be described based on FIGS. 1 to 4. Note that common parts in FIGS. 1 and 4 are denoted by the same reference numerals.

FIG. 1 is an electric circuit diagram of an embodiment of the present invention. In the figure, a discharge lamp lighting device 1 connects an AC power source 2 such as a commercial power source to a rectifier circuit 3, a smoothing capacitor 4, and a rectifier circuit 3. An inverter 5 that converts DC power into the required high-frequency AC power, a discharge lamp 6 such as a fluorescent lamp, and a filament preheating and starting capacitor 7 are electrically connected in order to constitute a lamp lighting circuit. By turning on the discharge lamp 6, the discharge lamp 6 is turned on at full brightness and high frequency.

One end of a dimmer switch 10 is electrically connected between the main switch 8 and the rectifier circuit 3, and one end of two voltage dividing resistors 11 and 12 is connected to the other end of the dimmer switch 10. , the anode of a first diode 13 is connected to the midpoint between these voltage dividing resistors 11 and 12.

The cathode of the first diode 13 is connected to the base of a PNP transistor 15, which is part of the starting means, and the emitter of the transistor 15 is provided with an adjustment resistor 14. Further, the collector of the transistor 15 is connected to the input terminal of the inverter 5 via a resistor 16. A constant voltage element 17 is provided in parallel with the collector-emitter of the transistor 15 and the resistor 14.

The transistor 15 is placed close to the discharge lamp 6, and due to its temperature characteristics, the ambient temperature is normal temperature (for example, 20~20°C).
The forward voltage between the base and emitter is increased when the ambient temperature is lower than 25° C.), and the forward voltage between the base and emitter is decreased when the ambient temperature is higher than room temperature.

A resistor 2 is installed at the midpoint between the voltage dividing resistors 18 and 19.
1 is connected to one end, and the other end is connected to the inverting input terminal of an operational amplifier 22, the gate of an FET (field effect transistor) 23 which is an output control element, a rectifier circuit 24, and a fourth winding of a saturable current transformer 25. 25-4 in this order, and the fourth winding 25-4 is connected to the first winding 25-4 of the inverter 5.
It is magnetically coupled to 1.

The inverter 5 is a FET as shown in FIG.
As the voltage VGS between the gate G and the source S of 21 increases in the ON direction, the output frequency is gradually lowered, and as the frequency fh is lowered to a lower frequency fl as shown in FIG. fo
The configuration is such that the output is gradually increased toward the peak of .

Therefore, when the FET 23 is turned on, the output of the inverter 5 increases, and when the FET 23 is turned off, the output decreases.

Next, the operation of this embodiment will be explained.

When the main switch 8 is on and the dimmer switch 10 is off, the transistor 15 is also off because the first diode 13 is off.

For this reason, the electricity V1 at the midpoint between resistors 18 and 19 shown in FIG. 4 is relatively low. This low potential is inverted and amplified to a high potential by the operational amplifier 22, and this high potential is further applied to the gate of the FET 23, turning the FET 23 on.

Since the FET 23 is turned on, the fourth winding 2
5-4 changes, the saturation time changes, the output frequency of the inverter 5 decreases as shown in FIG. 2, and the output of the inverter 5 increases as shown in FIG. is lit.

After this starting lighting, for example, the adjustment variable resistor 1
By the adjustment operation 4, it is possible to adjust the brightness of the total light as appropriate.

In order to dim the lighting of the discharge lamp 6, when the main switch 8 and the dimmer switch 10 are both turned on, or when the main switch is turned on with the dimmer switch 10 turned on, the discharge lamp 6 is turned on. The ambient temperature is normal temperature (
For example, when the temperature is higher than the temperature (about 20 to 25° C.), the discharge lamp 6 starts and lights up in a dimmable manner.

In other words, when the ambient temperature of the discharge lamp 6 is higher than room temperature, the forward voltage between the base and emitter of the transistor 15 is low, so a sufficient current flows through the resistor 20 through the transistor 15 to raise the potential V1. Make it high as shown in Figure 4. This high potential is inverted and amplified to a low potential by the inverting amplifier 22, and this low potential is applied to the gate of the FET 23.

For this reason, the FET 23 is turned off, so the output of the inverter 5 is reduced, and the discharge lamp 6 is dimmed and lit in accordance with the resistance values of the dimming variable resistors 14, 20, etc.

Therefore, after this starting lighting, it is possible to appropriately dim the discharge lamp 6 by adjusting the dimming variable resistors 14 and 20.

However, when the ambient temperature of the discharge lamp 6 is lower than room temperature, the forward voltage between the base and emitter of the transistor 15 is high, so the collector-emitter current of the transistor 15 decreases.

For this reason, the potential V1 between the resistors 18 and 19 decreases, and this low potential is inverted and amplified to a high potential by the operational amplifier 22. This high potential is applied to the gate of the FET 23, and the FET 23 is turned on. .

[0034] Since FET 23 is turned on, as described above,
Decreasing the output frequency of the inverter 5 as shown in FIG. 2 and increasing the output of the inverter 5 as shown in FIG.
The discharge lamp 6 is started and lit with full light.

Therefore, if the ambient temperature of the discharge lamp 6 is lower than room temperature, even if the dimmer switch 10 is turned on, the discharge lamp 6 will not be dimmed, but will be fully lit with a higher power. It stabilizes quickly.

This prevents the discharge lamp 6 from going out.

When the transistor 15 in the vicinity of the discharge lamp 6 is heated to above room temperature due to the heat generated by the discharge lamp 6 and other parts while it is being lit at full brightness, the base and emitter of this transistor 15 are heated to above room temperature. Since the forward voltage between the two is lowered, the lighting is controlled at a predetermined level.

After this, the discharge lamp 6 operates in the same manner as when the ambient temperature of the discharge lamp 6 is higher than room temperature, and the discharge lamp 6 is dimmed and lit. In other words, the brightness depends on the resistance value of resistor 20 etc.
Lights up dimmably.

Therefore, according to this embodiment, when the ambient temperature of the discharge lamp 6 is lower than normal temperature, the discharge lamp 6 is not started by dimming, but is turned on at full brightness with a power higher than the dimming. Since the lamp is started with , stable lighting can be achieved quickly and it is possible to prevent the lamp from going out.

Furthermore, since the discharge lamp 6 can be stabilized quickly,
Switching to dimming lighting can be performed early.

In the above embodiment, the case where the output from the midpoint between the resistors 18 and 19 is inverted and amplified by the operational amplifier 22 has been described, but the present invention is not limited to this. For example, as shown in FIG. Discharge lamp lighting device 31 shown
The FET 32, which is an output control element, may be provided with an inverting amplification function, and the output gain may be set by resistors 33 and 34 connected before and after the FET 32, respectively, as shown in FIG. Note that the potential V1 of each part in FIG.
, V2 and the ambient temperature is shown in Figure 7.

[0042]

As explained above, in the present invention, when the ambient temperature of the discharge lamp is lower than room temperature, the starting means does not dim the discharge lamp and lights it at full brightness, so that the discharge lamp can be started. It is possible to stabilize it early and prevent it from disappearing.

Furthermore, since the lighting of the discharge lamp can be stabilized quickly, switching to dimming lighting can be performed quickly.

[Brief explanation of drawings]

FIG. 1 is an electric circuit diagram of an embodiment of a discharge lamp lighting device according to the present invention.

FIG. 2 is a graph for explaining the action of the FET shown in FIG. 1.

FIG. 3 is a graph for explaining the operation of the inverter shown in FIG. 1;

FIG. 4 is a diagram showing voltages of main parts of the embodiment shown in FIG. 1;

FIG. 5 is a diagram showing voltages at main parts of the embodiment shown in FIG. 1;

FIG. 6 is an electrical circuit diagram of another embodiment of the invention.

FIG. 7 is a diagram showing voltages of main parts in FIG. 6;

[Explanation of symbols]

1,31 Discharge lamp lighting device 5 Inverter 6 Discharge lamp 10 Dimmer switch 14 Adjustable variable resistance 15 Transistor 19 Resistance 22 Operational amplifier 23 FET (output control element)

Claims (1)

[Claims] 1. A circuit for lighting a discharge lamp, a dimmer circuit for dimming lighting of the discharge lamp by turning on a dimmer switch, and a dimmer circuit interposed between the dimmer switch and the dimmer circuit for controlling the lighting of the discharge lamp. A transistor that changes a voltage signal to the dimmer circuit according to on/off of the optical switch, and a temperature characteristic of the transistor that is used when the ambient temperature of the discharge lamp is lower than room temperature when the dimmer switch is turned on. A discharge lamp lighting device comprising: a starting means for starting and lighting the discharge lamp with full light by controlling a voltage signal to the dimming circuit until the temperature reaches room temperature.