JPH01209698A - Metal vapor discharge lamp lighting device - 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 Industrial Application] The present invention relates to a lighting device for a high-pressure metal vapor discharge lamp such as a metal halide lamp, which is designed to prevent flickering phenomena.

[Conventional technology]

A so-called metal halide lamp, in which a metal halide is sealed together with mercury and a rare gas inside an arc tube equipped with a pair of electrodes, has good color rendering properties and high luminous efficiency, so it is used as a light source in various fields. There is.

However, because this type of lamp is lit vertically and contains metal halide, metal halide vapor is released inside the arc tube while the lamp is lit. Since balance occurs, various problems arise.

One such problem is the flickering phenomenon of light emitted when the lamp is turned on, and there is a problem in that it tends to cause discomfort, especially when this lamp is used as a light source for indoor lighting by being installed in a relatively low place.

This flickering phenomenon is caused by the lamp current waveform being different for each half cycle during lighting of the metal halide lamp and becoming asymmetrical as shown in Figure 6.The light output waveform based on this asymmetric lamp current is also shown in Figure 7. , the peak value fI every half cycle.

A major cause is that f2 is different and asymmetrical.

Conventionally, as a means to prevent such flickering phenomenon, a method has been used in which a lamp is lit using a DC power source or a high frequency lighting device is used.

Furthermore, in Utility Model Application No. 196496/1983, a current control circuit consisting of a parallel circuit of a resistor and a diode is connected in series or parallel to the arc tube and placed inside the lamp to eliminate flicker caused by the asymmetry of the lamp current. A method of mitigation is disclosed.

[Problem to be solved by the invention]

However, when lighting a lamp using a DC power source as described above, electrolytic phenomena occur in the electrodes of the arc tube, resulting in a short lamp life, and when lighting a lamp using a high-frequency lighting device, acoustic resonance phenomenon occurs. This has the disadvantage that the arc becomes unstable and extinction occurs. Furthermore, if a current control circuit consisting of a resistor and a diode is connected in series with the arc tube, the flickering phenomenon can be effectively prevented, but the diode may receive heat due to radiant heat and convection from the arc tube and the resistor. There is a problem in that a chemical reaction occurs and the lamp life is shortened, and therefore it is difficult to prevent flickering and to perform normal and reliable lighting operation over the lamp life period.

Furthermore, when this current control circuit is connected in parallel to the arc tube, the effect of reducing the flicker phenomenon is small (for lamps that are started by applying pulses, the pulse voltage decreases, causing poor startability). In addition, in order to implement flicker prevention using such a current control circuit, it is necessary to create a new lamp with a built-in current control circuit and replace it with the existing lamp. Therefore, the existing lamp must be discarded, which is extremely uneconomical.

The present invention has been made to solve the above-mentioned problems in conventional metal vapor discharge lamp lighting devices, and provides a metal vapor discharge lamp lighting device that uses conventional lamps and lighting equipment as is and has improved flickering. The purpose is to

[Means and effects for solving the problems] In order to solve the above problems, the present invention provides a current control circuit consisting of a parallel circuit of a resistor and a diode connected in series with a metal vapor discharge lamp. It is arranged outside the outer bulb of the discharge lamp to constitute a lighting device for a metal vapor discharge lamp.

With this configuration, the effects of heat from the diode arc tube can be reduced by using conventional metal vapor discharge lamps and lighting equipment as is, and simply installing a simple current control circuit between them. It is possible to maintain normal lighting operation without flickering over the life of the lamp, and there is no need to dispose of existing metal vapor discharge lamps and lighting equipment. lighting device can be provided.

〔Example〕

Examples will be described below. FIG. 1 is a schematic diagram showing a first embodiment of the present invention, and FIG. 2 is a diagram showing its circuit configuration. In Fig. 1, 1 is a 250W scandium-sodium metal halide lamp, and 2 is a lighting fixture with a socket for attaching an existing metal halide lamp.
Connected to 00v power supply. 3 is a socket with a base,
In the socket 3 with a cap, a current control circuit 6 consisting of a parallel circuit of a diode 4 and a nonflammable resistor 5, shown in a dotted frame in FIG. 2, is connected in series with the lamp 1 when the lamp 1 is attached. arranged to be connected. In Figure 2, 7 is a choke coil type ballast, and 8 is a 200 V ballast.
The power source is shown, and the nonflammable resistor 5 is as follows:
For example, an enameled resistor using nichrome wire is used.

The lamp 1 is attached to the socket 3 with a cap constructed in this way, and the socket 3 with a cap is attached to the socket/throat of the lighting fixture 2 which is connected to a power source via a ballast.
When the lamp was turned on, the surface temperature of the diode 4 placed in the socket 3 with a base reached 50°C. This relatively low surface temperature does not affect the life of the diode, and therefore, it is possible to effectively prevent flickering over the life of the lamp and ensure normal lighting operation.

The resistance value of the resistor 5 is set depending on the flickering value during lighting. The flicker values are shown in Fig. 7, and the peak value r of the light output for each half cycle is
,'rt, when expressed as a percentage value F of (f+fz)/r+, we measured the relationship between this value F and the resistance value R of the resistor 5, as shown in Figure 3. The results were obtained. In fact, it has been found that within the range of -2≦FF≦2, almost no flicker is felt. Therefore, from Figure 3, the resistance value R (Ω) to keep the flicker value F within this range is 2≦R (Ω)≦lO, and the power consumption is about 4W, so it does not cause much power loss and generates heat. The quantity is also small so that the resistor lasts for the life of the lamp.

FIG. 4 is a schematic configuration diagram showing a second embodiment of the present invention. The same members as those shown in the circuit diagram of the first embodiment shown in FIG. 2 are designated by the same reference numerals. In this embodiment, a current control circuit 6 consisting of a diode 4 and a non-combustible resistor 5 is placed inside a lighting fixture 2 with a socket that includes a choke coil type ballast 7. In this embodiment, unlike the first embodiment, the current control circuit IIB6 is
Since the diode 4 is placed in the lighting fixture 2 completely separated from the lamp, the heat received by the diode 4 is only the heat generated from the non-flammable resistor 5, and the diode 4 receives only the heat generated from the nonflammable resistor 5.
surface temperature rises only to about 35℃ (ambient temperature 2
0°C), therefore, the diode 4 can be used at even lower temperatures even if the lamp is lit until its lifespan, and no problems will occur.
As shown in the figure, by using a variable resistor 9 and appropriately selecting its resistance value, it is possible to deal with variations in flickering from lamp to lamp.

Although each of the above embodiments uses a 250 W scandium-sodium type metal halide lamp, the present invention can also be applied to metal halide lamps of other wand numbers and other types of metal vapor discharge lamps. is possible. In that case as well, flickering can be effectively prevented by using a resistor having a resistance value similar to that of the above embodiment. Incidentally, since a high-wattage lamp for boat fishing has less flickering, the resistance value of the resistor can be made slightly smaller in the case of a high-wattage lamp.

(Effects of the Invention) As described above based on the embodiments, according to the present invention, a current control circuit for flickering prevention consisting of a parallel circuit of a diode and a resistor is provided outside the outer bulb of a metal vapor discharge lamp. Since the conventional metal vapor discharge lamp and lighting equipment are used as they are, normal and reliable lighting operation that prevents flickering can be performed over the life of the discharge lamp.

[Brief explanation of the drawing]

FIG. 1 shows a first embodiment of a metal vapor discharge lamp lighting device according to the present invention.
2 is a diagram showing the circuit configuration of the embodiment, FIG. 3 is a diagram showing the relationship between the resistance value of the resistor constituting the current control circuit and the flicker value, and FIG. , FIG. 5 is a circuit diagram showing a modification of the second embodiment, FIG. 6 is a diagram showing lamp current waveform characteristics of a metal halide lamp, and FIG. The figure is a diagram showing the optical output waveform characteristics of a metal halide lamp. In the figure, 1 is a metal halide lamp, 2 is a lighting fixture with a socket, 3 is a socket with a base, and 6 is a current control circuit.

Claims (1)

[Claims] 1. A current control circuit connected in series with the metal vapor discharge lamp and consisting of a parallel circuit of a resistor and a diode is arranged outside the outer bulb of the metal vapor discharge lamp. Lighting device for metal vapor discharge lamp. 2. The lighting device for a metal vapor discharge lamp according to claim 1, wherein the resistance value R (Ω) of the resistor of the current control circuit is within a range of 2≦R (Ω)≦10.