JPH043624B2 - - Google Patents

Description

[Detailed description of the invention]

This invention has a new ballast built into the outer bulb of the lamp, which includes an arc tube made of translucent ceramic and filled with sodium, mercury, and xenon gas, and a direct resistor connected in series to the arc tube. This relates to high-pressure sodium lamps. High-pressure sodium lamps have recently begun to be widely used due to their high efficiency and long life.However, in order to light these lamps, external ballasts are required, and for this reason, they are often used in stores and temporary construction sites where it is difficult to install external ballasts. It was unsuitable for on-site use. Therefore, similar to the conventional high-pressure mercury lamps with built-in ballasts, high-pressure sodium lamps also have a resistor made of tungsten filament placed inside the lamp's outer bulb and connected in series with the arc tube to achieve high efficiency and long life. It is desired to realize a high-pressure sodium lamp with a built-in ballast that takes advantage of this. Compared to mercury lamps and metal halide lamps, high-pressure sodium lamps have a higher re-ignition voltage and are more likely to turn off even when lit with a widely used chioke type (slow-phase type) external ballast, and are therefore more likely to turn off. The rated arc tube voltage during lighting is 130V for mercury lamps, while high-pressure sodium lamps are designed to be approximately 30V lower, at approximately 100V, although this varies depending on the lamp size (wattage). If a ballast made of a resistor is applied to such a high-pressure sodium lamp, the phases of the discharge sustaining voltage and the arc tube voltage will be exactly the same, making it easier to turn off the lamp. If the arc tube voltage is further lowered to prevent this extinction, the voltage ratio consumed by the resistor will increase, and the lamp efficiency will decrease significantly.
To date, high-pressure sodium lamps with built-in ballasts have not been put into practical use. Therefore, in order to lower this restriking voltage and increase the efficiency, we conducted an experiment focusing on the point that the restriking voltage was reduced by increasing the diameter of the arc tube. ), the arc tube voltage is Vb
(volts), and the inner diameter of the arc tube made of translucent ceramic body is D (mm).This purpose is achieved when the following conditions are simultaneously satisfied: 0.0057Wl+4.53≦D≦0.0067Wl+6.27 0.02Wl+100≦Vb I confirmed that it can be achieved. The present invention will be explained below based on Examples and experimental results. Figure 1 shows the configuration of the high-pressure sodium lamp with a built-in ballast used in the experiment.Inside the outer bulb 1 kept in a high vacuum, there is an arc tube 2 made of a translucent ceramic tube; A resistor 3 consisting of tungsten filaments connected in series is provided. Further, a proximal conductor 4 is provided as a starting auxiliary external electrode close to the outer surface of the arc tube 2, and this proximal conductor 4 is connected to a high voltage pulse terminal of a high voltage pulse generator 6 housed in a base 5. It is connected. The arc tube 2 is filled with sodium, mercury, and xenon gas as a starting gas, and when power is applied to the lamp, a high voltage pulse generator 6
A high voltage pulse generated from the arc tube is applied to the adjacent conductor 4, discharging the xenon gas sealed in the arc tube
The lamp is turned on and the tungsten filament, which is a ballast built into the lamp, brings the lamp into a stable lighting state.
As can be seen from Figure 2, which shows the relationship between the xenon gas filling pressure and the pulse voltage required for starting, in a lamp configured to start by applying a high voltage pulse to a nearby conductor, if the xenon gas filling pressure exceeds 100 torr. The pulse voltage required for starting increases,
Additionally, as the lamp lighting time elapses, debris from the electrodes 7 and 7' provided at both ends of the arc tube, or sodium and mercury adhere to the inner wall of the arc tube, preventing the effect of the adjacent conductor and reducing the pulse voltage required for starting. Therefore, in order to ensure that the lamp starts over its lifetime, the xenon fill pressure in the arc tube must be
It is better to keep it below 100 torr, preferably around 50 torr. Next, we will explain the experimental results of a 400-watt high-pressure sodium lamp with a built-in ballast. Table 1 shows the specifications of the arc tube used in the test.

[Table] Note that the tube wall load is the value when the arc tube power Wb is 200 W, and is approximately equal to the tube wall load of the arc tube of a normal high-pressure sodium lamp in terms of life and efficiency. The xenon gas inside the arc tube is 50 torr, which gives the highest arc tube efficiency lm/Wb for each arc tube diameter D.
Sodium and mercury are sealed so that a predetermined arc tube voltage Vb can be obtained. Using these arc tubes and variable resistors, the lamp power Wl can be achieved with a power supply voltage of 200V.
Table 2 shows the results of measuring various characteristics when the power was 400W.

[Table] Here, the light emission voltage Vb is the upper limit value at which discharge can be maintained when the power supply voltage is 180V, taking into account fluctuations in power supply voltage during actual use. is determined automatically. As can be seen from Table 2, the arc tube efficiency lm/Wb reaches its maximum value when the arc tube diameter D is 7 mm, but when the arc tube diameter D becomes thicker, the vapor pressure of mercury inside the arc tube increases, causing an increase in mercury luminescence. As the effective luminous length becomes shorter, the arc tube efficiency lm/Wb decreases, but by increasing the upper limit of the arc tube voltage Vb, the arc tube power increases, so the lamp efficiency lm/Wb decreases.
Wl shows the highest value when the arc tube diameter D is 8 mm.
Figure 3 shows the arc tube diameter D and lamp efficiency lm/Wl in Table 2.
This is a diagrammatic representation of the relationship between lamp efficiency and
From a practical standpoint, lm/Wl is at least 90% of the maximum value of 50lm/Wl when the arc tube diameter D is 8 mm, that is.
To satisfy 45lm/Wl, the arc tube diameter should be 6.5~
It can be said that the range of 9.2 mm (shaded area) is sufficient.
However, when the lamp efficiency lm/Wl becomes 45 or more when the lamp power Wl is constant at 400W, the arc tube diameter D
From Fig. 4, which shows the relationship between the arc tube voltage and the arc tube voltage, it is preferable that the arc tube voltage Vb is in the range of 10 V or more, at least from the standpoint of reliability and lamp yield, and for that purpose the arc tube diameter D should be 6.8 to 8.9 mm. There is a need. Optimally, by setting the arc tube diameter D to 8 mm,
The arc tube voltage Vb can range from 110 to 140V and 30V. Next, we performed the same experiments on 700 watt and 1000 watt high-pressure sodium lamps with built-in ballast as we did on 400 watt built-in ballast lamps, and the results were as follows. Figures 5 and 6 show the results. From Figure 5, at 700 Watts, the arc tube diameter D is approximately 10
mm, the maximum lamp efficiency lm/Wl is 55, and at 1000 watts, the maximum lamp efficiency lm/Wl is approximately 12 mm when the arc tube D is 12 mm.
It will be 60. Same as 400 watts, lamp efficiency lm/Wl
is more than 90% of the maximum lamp efficiency, and from FIG. 6, the arc tube diameter D at which the arc tube voltage Vb range is 10 V or more is 8.5 to 11.0 mm at 700 Watts and 10.2 to 12.9 mm at 1000 Watts. In that case, the lower limit of the arc tube voltage Vb is 115V at 700 Watts and 122V at 1000 Watts. Figures 7 and 8 summarize the above results. Figure 7, which shows the relationship between lamp power Wl and arc tube diameter D, shows that the lamp efficiency lm/Wl is more than 90% of the maximum lamp efficiency, and the luminescence Tube voltage Vb range 10V
In order to achieve the above, the diameter of the arc tube must be within the shaded range, and from FIG. 8, the arc tube voltage Vb must also be at least within the shaded range. That is, the arc tube diameter D and the arc tube voltage Vb must simultaneously satisfy the following two equations for the lamp power Wl: 0.0057Wl+4.53≦D≦0.0067Wl+6.27 and 0.02Wl+100≦Vb. According to the present invention, by satisfying the above formula, it has become possible to obtain a high-pressure sodium lamp with a built-in ballast that is highly efficient and stably lit throughout its life.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the high-pressure sodium lamp with a built-in ballast according to the present invention, and Figures 2 to 8 are characteristic diagrams adopted to explain the present invention based on experimental results. Figures 3 and 4 are diagrams showing the relationship between the filling pressure and the pulse voltage required for starting, and Figure 4 is a diagram showing the relationship between the arc tube diameter, lamp efficiency, and arc tube voltage in a 400 watt lamp, and Figure 5 is Figure 6 is a diagram showing the relationship between arc tube diameter, lamp efficiency, and arc tube voltage for 700 Watt and 1000 Watt lamps, Figure 7 is a diagram showing the relationship between lamp power and arc tube diameter, and Figure 8 is lamp power. FIG. 3 is a diagram showing the relationship between the arc tube voltage and the arc tube voltage. 1... Outer tube, 2... Arc tube, 3... Resistor, 6
...Pulse generator, 4...Proximity conductor.

Claims (1)

[Scope of Claims] 1. Inside the outer bulb of the lamp, there is an arc tube made of a translucent ceramic tube and filled with sodium, mercury, and xenon gas as a starting gas, and a resistor connected in series with the arc tube. In high-pressure sodium lamps with built-in ballasts connected to
(W), the arc tube voltage is Vb (V), the inner diameter of the arc tube is D
(mm) 0.0057Wl+4.53≦D≦0.0067Wl+6.27 0.02Wl+100≦Vb A high-pressure sodium lamp with a built-in ballast. 2 Inside the lamp's outer bulb, there is an arc tube made of a translucent ceramic tube with sodium mercury and xenon gas as a starting gas sealed inside, and a built-in ballast with a built-in resistor connected in series to the arc tube. In high-pressure sodium lamps, the lamp power is
When Wl (W), the arc tube voltage is Vb (V), and the inner diameter of the arc tube is D (mm), the following conditions are simultaneously satisfied: 0.0057Wl+4.53≦D≦0.0067Wl+6.27 0.02Wl+100≦Vb, and xenon A high-pressure sodium lamp with a built-in ballast, characterized in that the gas filling pressure is 100 torr or less and the lamp is started by applying a high voltage pulse to a conductor provided close to the outer surface of the arc tube.