JPS6056354A - Starter built-in type high pressure sodium lamp - Google Patents

Abstract

PURPOSE:To enable an accurate start under all operating conditions by providing a heat insulating body at the end of a luminous tube in which an electrode having the potential opposed to a starting auxiliary conductor and making the thermal conductivity of a conductor to this electrode smaller than the thermal conductivity of a conductor on the other end. CONSTITUTION:A starting auxiliary conductor 4 touches the outer surface of a luminous tube 1 at start and is separated from the outer surface of the luminous tube through a bimetal piece 5 at lighting. In addition, a heat insulating body 9 made of a heat resistant metal sheet is mounted on the outer surface of the side in which an electrode that has the potential opposed to the auxiliary conductor 4 at start is located so that the temperature of this section can relatively become higher than the temperature of the other end of the luminous tube 1 while a lamp is operating. Furthermore, for a conductor 10 that is positioned at the side where the insulating body 9 is provided, the thermal conductivity is reduced relatively, for example, by a method of reducing a crosssectional area, etc., as compared with a conductor 11 on the other end.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improvement in a high-pressure sodium lamp incorporating a glow starter as starter.

Conventional structure and its problems Conventionally, high-pressure sodium lamps with a built-in starter have a bimetal switch as a starter, which uses a combination of a bimetal switch and a resistor to heat the starter and open the circuit. There are two types: one that uses a glow starter, and one that uses a glow starter.

Among these, in the bimetal switch method, the contacts of the bimetal switch are opened inside the vacuum outer sphere, so
The ratio of electromagnetic energy stored in the inductance of the ballast when the circuit is opened is consumed by discharge between the contacts of the bimetal switch is small, and compared to the glow starter method, essentially a lower pulse voltage can be obtained. It is difficult to control the height of the pulse voltage to a certain constant value, for example, 4KV or less, and it depends on the phase of the current at the moment the bimetal switch opens and the opening speed of the bimetal switch contact.
Since pulse voltages of ~sKV can occur,
Sufficient consideration must be given to the electrical insulation of the lighting circuit.

On the other hand, in the glow starter method, the contacts of the glow starter are opened in the rare gas sealed in the glow starter, so a part of the electromagnetic energy stored in the inductance of the ballast at the time of opening is transferred to the contacts. Since the voltage is lost due to intermittent discharge, the magnitude C of the pulse voltage cannot exceed a certain value (approximately 2 KV). The maximum value of the pulse voltage can be controlled to some extent by the composition and pressure of the gas filled in the glow starter. For this reason, the glow starter method is often adopted for low-wattage, high-voltage thorium lamps that do not require a very high pulse voltage to start the discharge of the arc tube.

Figure 1 shows an example of a conventional high-pressure lamp with a built-in glow starter. In the figure, reference numeral 1 denotes an arc tube made of a translucent ceramic tube, which is equipped with a pair of electrodes at both ends.
00 Torr of xenon is sealed. 2 is a glow starter, 3 is a bimetal switch for cutting off the potential to the glow starter during stable operation of the 1
, 4 are starting auxiliary conductors which are kept away from the surface of the arc tube 1 by a bimetal 85 during stable operation of the lamp. 6 is an outer bulb, and 7 is a base 1. When a power supply voltage is applied to the lamp configured in this way through an inexpensive device 8, the glow scooter 2 starts to operate after 1 to 2 seconds, and after that for 1 second. A pulse voltage is induced in the ballast 8 at a frequency of several dozen times. Normally, due to this voltage, the light emitting device 31 starts discharging within 6 seconds after the power supply voltage is applied.

However, when starting tests were conducted on a large number of lamps of this type under various usage conditions, it was found that with conventional lamps, when the lamp was turned on for only a few seconds after starting, turned off, and the power supply voltage was applied again after cooling, the glow starter 2 It has become clear that a phenomenon may occur in which the arc tube 1 does not start discharging even though it is operating normally. The reason for this is thought to be as follows. When a stably lit lamp is turned off, as is generally done in normal circumstances, the sodium amalgam present in gaseous form in the arc tube 1 is removed behind one or both electrodes at the end of the arc tube 1. Condense. When the lamp is started again after cooling, the moment the arc tube 1 starts discharging, the sodium amalgam that had condensed behind the electrodes scatters and adheres to the inner wall of the arc tube around the nearby electrodes.

Under normal usage conditions, the power switch is turned on in this state.

Since the chi is not cut, the temperature of the arc tube 1 rises.17Nitsu circles are attached to the wall of the arc tube around the electrodes.)
l) All of the ram amalgam will have evaporated, and some of it will condense again in the coldest part behind the electrode. The sodium amalgam attached to the wall in a mirror-like manner remains in its 1-inch state. After cooling the lamp in this condition, start it again! I (!l depending on the case!-1 mirror-like) l) One, the amalgam is,
2) If attached to the outer surface of the arc tube 1, it may become an electrical shield between the starting auxiliary conductor 4 and an electrode at an opposite potential, and the effectiveness of the starting auxiliary conductor 4 may be significantly inhibited. .

Even in lamps in which such a phenomenon has occurred, when a pulse voltage higher than the pulse voltage from the glow starter is applied from the outside, the lamp starts discharging and thereafter operates without any problem under normal usage conditions.

The probability of such a phenomenon occurring is 1. In the event of a power outage, etc., there is no guarantee that the problem will not occur, and in that case, you will have to change the lamp and replace it.

The present invention (1) has been developed in view of the above-mentioned circumstances, and under the above-mentioned special conditions of use, even if the light is turned off within a few seconds after the discharge of the arc tube starts, The object of the present invention is to provide a high-pressure sodium l-lamp with a built-in starter that operates reliably.

Structure of the Invention In order to achieve the above object, the high pressure sodium lamp with a built-in starter according to the present invention is provided with a heat insulator at the end of the arc tube where an electrode at a potential opposite to the starting auxiliary conductor is located; The conductor is configured so that the thermal conductivity of the conductor to the electrode is smaller than the thermal conductivity of the conductor to the other end electrode, and when the lamp is off, the rear of the electrode (at the opposite potential to the starting auxiliary conductor) Prevents sodium amalgam from condensing.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a diagram showing an embodiment of the high pressure IJ umlumb in the starter according to the present invention. In the figure, reference numeral 1 denotes an arc tube made of translucent ceramic 7-piece tube, equipped with a pair of electrodes at both ends, and with sodium amalgam.
Enclosed is 2 QOTorr of xenon. 2 is a glow starter, and when the lamp is in stable operation, the bimetal switch 3 is opened so that no voltage is applied. During stable lighting of the lamp, the bimetallic piece 5 keeps it away from the outer surface of the arc tube 1. 6 is the bulb, and 7 is the base. ki2 is placed on the outer surface of the side where the electrode facing the potential that is opposite the conductor 4 is located, so that the temperature of this part becomes relatively higher than the temperature of the other end of the arc tube 1 during operation of the lamp. The heat insulating body 9 made of a plate is removed.For example, the conductor 10 on the side where the heat insulating body 9 is provided is compared with the conductor 11 at the other end. Thermal conductivity can be made relatively small by reducing the size of the material.

Starting R of the present invention configured as described above: ÷ Built-in positive high voltage/During stable lighting of the SOUM lamp, the coldest point inside the arc tube 1 is always at the electrode opposite to the base 7 in FIG. This occurs at the rear, and excess sodium amalgam will condense in this area. When the lamp is turned off while it is in a stable lighting state, due to the difference in thermal conductivity between the conductors 10 and 11, the side where the excess thorium amalgam is condensed cools down relatively faster at the end of the arc tube. Therefore, most of the sodium amalga, which existed in the gaseous state in the arc tube, condenses at the end of the arc tube, and therefore, when the lamp is off, the light emitting material on the side where the heat insulator 9 is provided condenses. Almost no thorium amalgam is condensed at the end of the tube.

Even if the lamp is started in this condition and turned on for several seconds and then turned off, there is almost no adhesion of l/um amalgam to the inner wall of the tube around the electrode that is at a potential opposite to the starting auxiliary conductor 4. This is not recognized, and the discharge of the arc tube 1 is reliably carried out even at the next start-up.

Note that the thermal conductivity of the conductor connected to each electric conductor is set to be yti (the LC may be made of a material having different thermal conductivity).

Next, an experimental example in which the effects of the present invention were confirmed will be explained.

IR electrodes were attached to both sides of a translucent alumina tube of which 11 was 4.5, and about 100 Torr of xenon was sealed inside along with 20 rng of sodium amalgam.110
W luminous tube and a group that can obtain a pulse voltage of approximately 1600V.
We prepared 30 lamps each using a conventional structure using a coaster and 30 lamps according to the present invention.
1 when the light is turned on for 0 seconds and turned off for 30 minutes.
The probability that a discharge would start within 10 seconds at a power supply voltage of 80 μm was compared.

Measurements were repeated three times for each of a total of 60 lamps, and even for lamps that did not start discharging under the above conditions in one test, the power supply voltage must be adjusted to improve the voltage for the next test. By this means, I made sure to turn on the light again for 10 seconds and turn it off for 3 () minutes.

As a result, while the lamp with the conventional structure had a ratio of approximately 2φ at which discharge did not start under the conditions listed in (1) and (1), the ratio was zero in the lamp of the present invention.

DETAILED DESCRIPTION OF THE INVENTION As described above, the present invention provides the following advantages: 1. l) Controlling the condensation location of the ram amalgam.Providing a high-pressure thorium lamp in a starter that has the excellent effect of reliably starting the lamp under all conditions of use. It is something that can be done.

[Brief explanation of the drawing]

Figure 1 shows a conventional high-pressure sodium lamp; Figure 2 shows a conventional high-pressure sodium lamp;
The figure (is a diagram showing a high-pressure sodium lamp which is an embodiment of the present invention. 1. Arc tube, 2.. glow starter, 3.-.9
Shita・・hei・chi・・Starting auxiliary conductor,・・・Outer sphere, 9・・Heating body, 10.11・・・・Conductor. Agent 6: Patent attorney Toshio Nakao and 1 other famous person
1 figure

Claims (1)

[Claims] A light-transmitting ceramic tube is equipped with a pair of electrodes at both ends, and has a starting rare gas and sodium amalgam sealed inside. A glow starter is housed in an outer bulb, and a starting auxiliary conductor is attached to the outer surface of the arc tube across both grooves, and the electrode has a potential opposite to that of the starting auxiliary conductor when the lamp is started. A heat insulator is provided at the end of the arc tube where the heat insulator is located, and the thermal conductivity of the conductor connected to the electrode on the side where the heat insulator is located is lower than the thermal conductivity of the conductor connected to the other electrode. A high-pressure Natriu J lamp with a built-in starter.