JPS5979994A - Method of firing high pressure sodium 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 Field of the Invention The present invention relates to a method for lighting a high-pressure sodium lamp using a ballast having a secondary open-circuit effective voltage of 150 V or less.

Conventional Structures and Problems Incandescent light bulbs have been widely used as one of the main lamps for indoor lighting because they have good color rendering properties and are easy to install and remove in general households. but,
As we enter an era of full-fledged energy conservation, the low efficiency of light bulbs is becoming a problem, and recently there has been a strong demand for the development of compact, high-brightness discharge lamps to replace light bulbs.

In particular, small high-intensity discharge lamps that emit light with almost the same color as incandescent light bulbs, which have been widely used by the general public, have not yet been commercialized. Moreover, the application was filed as a lamp that has the potential to meet the strong demand for a high-intensity discharge lamp with a lamp power of 20 to 100 W and a luminous flux in the 60 to 20 OW class of an incandescent bulb. The person is Japanese Patent Application Laid-Open No. 57-9045,
In Japanese Unexamined Patent Publication No. 57-50763, a high-pressure sodium lamp was proposed which has almost the same light color and color rendering properties as an incandescent lamp, and whose lamp efficiency is two to three times that of an incandescent lamp.

A small, low-wattage lamp prototyped based on this proposal exhibits a light color similar to that of an incandescent light bulb, and a 5oW lamp, for example, has a lamp efficiency that is approximately three times that of a light bulb. Moreover, this lamp can be powered by a commercial AC power supply, i.e. 50 to 60) HFL 00 to 120V, in a small size,
Another feature is that it can be lit using a lightweight ballast, and for this reason, the distance between the electrodes of the arc tube and the tube voltage at rated lighting are lower than those of conventionally designed high-pressure sodium lamps. It is designed to be extremely small. For example, in the case of this soW high pressure sodium lamp,
Although the total length of the arc tube is 40M&-, the distance between the electrodes is 10JEI, and the lamp voltage at rated point firing is 40~eoV.
The ballast is designed so that the secondary open circuit effective voltage is 90 to 150V.

However, in a high-pressure sodium lamp with such a design, the secondary open circuit effective voltage of the ballast is as low as 90 to 150 V, making it difficult to start the lamp. In addition, this results in an extremely long glow discharge time when the lamp is turned on, resulting in a situation where the lamp does not easily transition to arc discharge. When starting the lamp, the electrode material scatters and evaporates heavily.
Therefore, as this starting time becomes longer, the blackening of the arc tube progresses rapidly. Therefore, especially in the case of a small high-pressure sodium lamp having a very small distance between the electrodes as described above, the luminous flux of the lamp rapidly decreases as the lamp is turned on.

OBJECTS OF THE INVENTION The present invention has been made in view of these problems, and provides a lighting method that can reliably start a high-pressure sodium lamp that is lit by a ballast with a secondary open circuit effective voltage of 160 V or less. It is something.

Structure of the Invention The present invention applies an AC power supply voltage through a ballast with a secondary open circuit voltage of 15 ov or less, and further applies a pulse voltage superimposed on this AC power supply voltage to produce a high-pressure sodium molar ratio. A lighting method, wherein the phase angle of the AC power supply voltage is in the range of 40 degrees to 105 degrees or 220 degrees to 286 degrees, and the pulse voltage is applied to high-pressure sodium in at least one of the positive and negative half cycles of the AC power supply voltage. The voltage is applied to the lamp.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of an arc tube used to carry out the method of lighting a high-pressure sodium lamp of the present invention. In the same figure, 1 has an inner diameter at the center, that is, a maximum inner diameter of 5.
, Omtb is an alumina arc tube, and electrode conductors 2 and 3 made of niobium tubes are each directly sealed on the inner surfaces of both ends with ceramic cement. Electrodes 4 and 6 are held at the tips of the electrode conductors 2 and 3,
The shortest distance between these electrodes is 1ONk. The arc tube 1 has a maximum inner diameter of 6.0 mm at its center, but the inner diameter is narrowed from near the electrodes 4 and 6 to the ends of the arc tube 1, and the electrode conductor 2 ,3
is sealed. At the ends, the outer diameter is approximately equal to the outer diameter of the electrode conductors 2 and 3. Inside the arc tube 1, there is a sodium amalgam 6 with a sodium molar ratio of 78% and a neon-argon mixed gas of about 40 Ton as a starting rare gas.
rr enclosed.

FIG. 2 shows the electrical circuit on which the lamp starting experiment was conducted. Finally, the luminous tube 1 is incorporated into the outer tube 8.
This is a 0W high pressure sodium lamp with high color rendering properties, and a sine wave AC power source 10 is connected to this high pressure sodium lamp 7 via a choke type ballast 9. A high-pressure pulse generator 11 is connected in parallel with the high-pressure sodium wrap 7, so that a pulse voltage can be applied between both terminals of the high-pressure sodium lamp, and after the lamp starts, the pulse voltage is generated as usual. is supposed to stop. That is, as shown in FIG. 3, between both terminals of the high-pressure sodium lamp 70, a sine wave AC power supply voltage 12 of 60141 with a secondary open circuit effective voltage E□ of 100 V is applied via the ballast 9. , and a pulse voltage 13 having a half-width of ΔW1 and a peak voltage of vo-p is applied to the AC power supply voltage 120 at a phase angle θ at least every cycle. However, the peak of the sine wave is 90 degrees. And these characteristic values ΔW of the □ pulse voltage 13.

(2) o-P and θ can be set to arbitrary values.

An experiment was conducted to start the high-pressure sodium lamp 7 using the lighting circuit configured as described above. In the experiment, the secondary open circuit effective voltage E of the ballast 9. The aim was to find the necessary voltage for the lamp to start within 10 seconds after applying a superimposed pulse voltage 13 to the AC power supply voltage 12 to the high-pressure sodium lamp 7 under a constant voltage of 100V. .

FIG. 4 shows the relationship between the phase angle θ of the pulse voltage 13 required to start the lamp and the AC power supply voltage 12 when the half width ΔW of the pulse voltage 13 is 15 microseconds. As is clear from the figure, if the pulse voltage 13 is applied every cycle within the range of AC power supply voltage 120 and phase angle θ of 40 degrees to 1045 degrees, the high-pressure sodium lamp can produce a high-pressure sodium lamp with a peak voltage vO-P of around 1Kv. It can be seen that it starts easily at low voltage. On the other hand, if the phase angle θ deviates from this range, lamp starting becomes difficult and the peak voltage vo-P must be increased. In particular, when the value of the phase angle θ increases, it suddenly becomes difficult to start the lamp, and when the phase angle θ reaches 110 degrees, in the case of this example, when the AC power supply voltage 12 and the pulse voltage 13 are applied, After that, it was found that a peak voltage of 70 volts, which is as high as 4 KV or more, is required for arc discharge to start within the arc tube 1 within 10 seconds.

There was almost no change in the narrow case of about 1 microsecond or the wide case of about 100 microseconds. Furthermore, almost the same results were obtained even when the secondary open circuit effective voltage EO of the ballast 9 was increased to about 160V.

It goes without saying that such experimental results do not change even when a pulse voltage is applied to the negative side of the AC power supply voltage 12. That is, if a pulse voltage is applied to the high-pressure sodium lamp T when the phase angle θ of the AC power supply voltage 12 exceeds 285 degrees, it will be very difficult to start the lamp as described above, and the pulse voltage will be applied at the same time as the AC power supply voltage 12. A pulse voltage with an absolute value of 4 KV or more is required to start the lamp within 10 seconds after applying the voltage.

As mentioned above, the phase of the pulse voltage applied to the lamp with respect to the AC power supply voltage exceeds 105 degrees, for example, 116 degrees.
or after 285 degrees, for example 29
The phenomenon in which starting becomes suddenly difficult when the temperature reaches 6 degrees Celsius is not limited to this example, but is a common phenomenon in all high-pressure sodium lamps lit by ballasts with a secondary open circuit effective voltage of 1 sov or less. This was confirmed.

In high-pressure sodium lamps equipped with such a starting means, lamp starting is easy and the starting time, that is, the glow discharge time is short, so that blackening of the arc tube when starting the lamp is suppressed as much as possible, resulting in an excellent lifespan. It was also confirmed that the characteristics could be obtained.

In the lighting circuit shown in FIG. 3, a high-voltage pulse generator is provided separately from the ballast, but it is also possible to use a ballast with a built-in high-voltage pulse generator.

Furthermore, in the above explanation, an example was given in which the pulse voltage is superimposed on the positive half cycle or the negative half cycle of the AC power supply voltage.
Of course, it is also possible to superimpose a pulse voltage on each positive and negative half cycle, which has the dynamic effect of making the lamp easier to start.

As described in detail, the present invention has a secondary open circuit effective voltage of 150
A high-pressure sodium rung lighting method that is lit by a ballast that is below V, the phase angle of the AC power supply voltage being 40
The lamp is started by applying a superimposed pulsed voltage to the high-pressure sodium lamp during at least one of the positive and negative half-cycles of the AC mains voltage in the range between 105° and 220° and 285°. This method can be carried out reliably and, as a result, the scattering of the electrode material at the time of starting the lamp is greatly suppressed, so that it is possible to provide a high-pressure sodium lamp lighting method that has excellent life characteristics.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an arc tube used to carry out the high-pressure sodium lamp lighting method of the present invention, FIG. 2 is a diagram showing an example of a lighting circuit for carrying out the high-pressure sodium lamp lighting method of the present invention, and The figure is a waveform diagram of the AC power supply voltage and pulse voltage applied to the high-pressure sodium lamp using the lighting circuit shown in Figure 2, and Figure 4 is a relationship diagram between the application position of the pulse voltage and the minimum value of the peak voltage. . 1... Arc tube, 2, 3... Electrode conductor, 4, 6...
...Electrode, 6... Sodium amalgam, 7
...High pressure sodium lamp, 8...Outer tube,
9...Ballast, 10.Pa...AC power supply, 11
. . . High voltage pulse generator, 12 . . . AC power supply voltage, 13 . . . Pulse voltage. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 @ Figure 2 Figure 3 490- Figure 4

Claims (1)

[Claims] A method for lighting a high-pressure sodium lamp, which is lit by applying an AC power supply voltage through a ballast having a secondary open circuit effective voltage of 150 V or less, and further applying a pulse voltage superimposed on the AC power supply voltage, the method comprising: The pulse voltage is applied to the high-pressure sodium lamp during at least one of the positive and negative half cycles of the AC power supply voltage, with the phase angle of the AC power supply voltage being in the range of 4Q degrees to 105 degrees or 220 degrees to 286 degrees. A high-pressure sodium lamp lighting method characterized by: