JPH0524618B2 - - Google Patents

Description

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

Conventional structure and its problems Conventional high-pressure sodium lamps with a built-in starter have a bimetal switch type starter that uses a combination of a bimetal switch and a resistor to heat and open the switch. , and one using a glow starter.

Among these, in the bimetal switch method, the opening of the bimetal switch is performed inside the vacuum outer sphere, so the proportion of electromagnetic energy stored in the ballast when the switch is opened is consumed by discharge between the contacts of the bimetal switch is small. , an essentially higher pulse voltage can be obtained compared to the glow starter method, but depending on the phase of the current at the moment the bimetallic switch opens and the opening speed of the bimetallic switch, the height required to start the discharge of the arc tube may vary. Above 4~
Since a pulse voltage of 5KV may be generated, sufficient consideration must be given to the insulation of the lighting circuit. On the other hand, in the case of the glow starter method, the contacts of the glow starter are opened in the rare gas sealed in the glow starter.
Part of the electromagnetic energy of the ballast when the circuit is open is lost due to discharge between the contacts, and the magnitude of the pulse voltage cannot exceed a certain value (approximately 2KV). That is, in the glow starter method, the magnitude of the maximum pulse voltage can be controlled to some extent by the composition, pressure, etc. of the gas filled in the glow starter. Therefore, it is not necessary to pay as much attention to the insulation of the lighting circuit as in the case of the bimetal switch system. For this reason, the glow starter method is often adopted for low-wattage, high-pressure sodium lamps that do not require a very high pulse voltage to start discharge in the arc tube.

An example of the circuit configuration of such a conventional high-pressure sodium lamp with a built-in glow starter is shown in FIG.

In FIG. 1, reference numeral 1 denotes an arc tube in which xenon as a starting rare gas is sealed together with sodium amalgam at a pressure of 100 to 200 Torr. 2 and 3 are electrodes, and 4 is a glow starter. 5 is a bimetal switch, but this is not intended to generate a pulse voltage, but is opened by the radiant heat from the arc tube 1 during operation of the lamp, and its role is to cut off the potential to the glow starter. It fulfills the following. Reference numeral 6 denotes an auxiliary conductor for starting, to which a second bimetal switch 7 prevents any potential from being applied while the lamp is in operation.
8 is an outside ball.

When AC power supply voltage is applied to the lamp configured in this way through the ballast 9, the glow starter 4 starts operating after 1 to 2 seconds, and thereafter pulses are sent to the ballast 9 at a frequency of several dozen times per second. A voltage is generated and discharge of the arc tube 1 typically begins within about 5 seconds after application of the power supply voltage. However, after conducting start-up experiments on a large number of lamps of this kind under various conditions, it was found that the following problems can occur in conventional lamps, although the occurrence rate is small. In other words, the lamp turns on and off for only a few seconds after starting, and then turns off.
When an attempt was made to start the lamp again after it had cooled sufficiently, it was discovered that although the glow starter 4 was operating normally, the lamp did not start discharging from the arc tube 1. This is considered to be because the lamp was turned on for only a few seconds, making it difficult to start the arc tube 1 for the following reasons.

That is, when the lamp is turned off after reaching a stable state as usual, the sodium amalgam that was present in the gaseous state in the arc tube 1 during lighting condenses behind the electrode 2 or 3 at the end of the arc tube 1. do. When a lamp in such a state is started, when discharge begins, the sodium amalgam that has condensed behind electrode 2 or 3 will scatter and adhere to the inner wall of the arc tube around the nearby electrode in a mirror-like manner. . During normal lighting, as the temperature of the arc tube 1 rises and the lamp enters a stable state, all of the sodium amalgam attached to the inner wall of the arc tube around the electrodes evaporates, and some of it returns to the coldest part behind the electrodes. It condenses at points. When the lamp turns off a few seconds after starting,
The sodium amalgam attached in a mirror-like manner to the inner wall of the arc tube around the electrodes remains as it is. If you restart the lamp after it has cooled down in this condition,
A mirror-like amalgam exists as a shield between the starting auxiliary conductor 6 provided on the outer surface of the arc tube 1 and the electrode 2 or 3.
This is thought to be one of the reasons why it is difficult to start the engine. Such a lamp also starts normally when a pulse voltage higher than the pulse voltage from the glow starter is applied from the outside, and thereafter operates without any problem under normal usage conditions.

This phenomenon is observed only in a small number of lamps manufactured under the same manufacturing conditions, and the reproducibility of the phenomenon in the same lamp is not high, but such a phenomenon may occur in practical lighting facilities due to power outages or other problems. This is not always possible under certain circumstances, and in that case the lamp must be converted.

Purpose of the Invention The present invention has been made in view of the above circumstances, and provides a built-in starter that operates normally even when the arc tube becomes difficult to start under the above-mentioned special conditions of use. The purpose is to provide a high pressure sodium lamp.

Structure of the Invention In order to achieve the above object, the high-pressure sodium lamp with a built-in starter of the present invention is provided with a pair of electrodes at both ends of a translucent ceramic tube with a starting aid conductor attached to the outer surface, and a starter conductor inside. Along with an arc tube filled with rare gas and sodium amalgam,
A series circuit of a first starter consisting of a glow starter and a second starter consisting of a bimetallic switch and a resistor connected in series to the bimetallic switch and for heating the bimetallic switch is connected in parallel to the luminous tube. It is connected and housed inside a vacuum outer sphere.

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

FIG. 2 shows an example of the circuit configuration of a high-pressure sodium lamp with a built-in starter according to the present invention.
In the figure, reference numeral 1 denotes an arc tube made of translucent ceramic, and electrodes 2 and 3 are provided at both ends.
Inside arc tube 1 is sodium amalgam.
100 to 200 Torr of xenon is sealed. 4
is a glow starter which is the first starter, 5 is a bimetal switch, 10 is a bimetal switch 5
This resistor is made of, for example, a tungsten filament. A second starter is constituted by a series circuit of bimetal switch 5 and resistor 10. 1st starter and 2nd
A series circuit with the starter is connected in parallel to the arc tube 1 and housed within the vacuum outer bulb 8. Reference numeral 6 denotes a starting auxiliary conductor attached to the outer surface of the arc tube 1. 7 is a second bimetal switch for cutting off the potential to the starting auxiliary conductor 6 during operation of the lamp.

When the high-pressure sodium lamp with a built-in glow starter according to the present invention configured as described above is connected to a power source via the ballast 9, normally, as in the case of a conventional high-pressure sodium lamp with a built-in glow starter, The glow starter 4 starts operating after ~2 seconds, and the discharge between the electrodes 2 and 3 of the arc tube 1 starts within about 5 seconds. When the discharge of arc tube 1 starts,
Since the voltage between the terminals of the glow starter 4 drops to 20 to 40V, the glow starter 4 stops operating. When the arc tube 1 reaches a stable state, the bimetal switch 5 is opened by the radiant heat from the arc tube 1, and the voltage application to the glow starter 4 is cut off.

Next, as mentioned above, if the lamp goes out several seconds after starting and becomes difficult to start, the pulse voltage generated by the operation of the glow starter 4 will not start discharging the arc tube 1. , the glow starter 4 continues to operate, but the temperature of the resistor 10 rises due to the current flowing through the glow starter 4.
After ~10 seconds, the bimetal switch 5 is opened.
At that moment, the bimetal switch 5 activates the vacuum outer sphere 8.
Since it is installed inside the ballast 9, 2~3KV is applied to the stabilizer 9.
A high pulse voltage is generated, and discharge of the arc tube 1 starts. If the first opening of the bimetal switch 5 does not result in the discharge of the arc tube 1 starting, the bimetal switch 5 recloses after 2 to 3 seconds and repeats the operation from the beginning, causing the arc tube to open again. 1
discharge will begin. In order to shorten the time from opening to re-closing the bimetal switch 5, the bimetal switch 5 and the heating resistor 1
It is preferable to keep the heat capacity of 0 as small as possible, and from this point of view, it is preferable that the heating resistor 10 be constructed of a tungsten wire filament.

Effects of the Invention As explained above, the present invention provides a starter that
A first starter consisting of a glow starter, and a second starter consisting of a bimetallic switch and a resistor connected in series to the bimetallic switch and for heating the bimetallic switch, and By housing the starter inside the vacuum outer bulb, it is possible to provide a high-pressure sodium lamp with a built-in starter, which has the excellent effect of reliably starting the lamp under all conditions of use.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the circuit configuration of a conventional high-pressure sodium lamp with a built-in glow starter, and FIG. 2 is a diagram showing the circuit configuration of a high-pressure sodium lamp with a built-in starter according to the present invention. DESCRIPTION OF SYMBOLS 1... Arc tube, 2, 3... Electrode, 4... Glow starter, 5... Bimetal switch, 6... Starting auxiliary conductor, 8... Outer bulb, 10... Heating resistor.

Claims (1)

[Claims] 1. A first starter consisting of a glow starter and a luminous tube comprising a pair of electrodes at both ends of a translucent ceramic tube with a starting auxiliary conductor attached to its outer surface and a starting rare gas and sodium amalgam sealed inside. A series circuit consisting of a bimetallic switch and a second starter connected in series with the bimetallic switch and consisting of a resistor for heating the bimetallic switch is connected in parallel to the arc tube, and a series circuit is connected in parallel to the arc tube. A high-pressure sodium lamp with a built-in starter.