JPH03219594A - Metal halide lamp starter - Google Patents

Abstract

PURPOSE:To ensure re-starting of a lamp, and to prevent early deterioration of a condenser by arranging one of thermal reaction switches of the same structure, staying on the side of a non-linear ferroelectric ceramic condenser on the base side of the lamp, and the other staying on the side of an auxiliary electrode on the top side of an outer bulb. CONSTITUTION:A thermal reaction switch 112 staying on the side of a non-linear ferroelectric ceramic condenser(FEC) and a thermal reaction switch 130 staying on the side of an auxiliary electrode, are made of bimetals of the same structure, and the switch 112 is set on the side of a base 140 that is in a higher temperature region of a lamp, while the switch 130 is set on the top side of an outer bulb 125 that is in a lower temperature region. In this structure, since the switch 112 is operated ON later than the 130 at the time of re-starting of the lamp, after the discharging is ready to take place between a primary electrode 124a and a starting auxiliary electrode 120, the switch 112 is turned ON, and discharging is started between the respective electrodes 124a and 120, thereafter, discharging occurs between the respective primary electrodes 124a and 124b, and the lamp is surely lighted thereby. Any wasteful pulse or voltage is thus not applied to FEC, and restarting is ensured, while early deterioration of FEC can be prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a starting device for a metal halide lamp that is lit with the base (cap) facing upward and the outer bulb containing the luminous tube facing downward, and particularly to a starting device for the switch thereof. Regarding improvements.

[Prior Art] Metal halide lamps have a spectrum covering the entire visible range, have excellent color rendering properties, and have good luminous efficiency, so they are widely used in the field of lighting for sports, commercial facilities, and the like.

By the way, in order to start this metal halide lamp, a starting device as shown in FIG. 5 has conventionally been incorporated and used.

First, the starting device shown in FIG. 5(A) includes a thermally responsive switch 12, a nonlinear ferroelectric ceramic capacitor (hereinafter referred to as FEC) 14 connected in series with the switch 12, and connected in parallel with the FECI 4. starting resistance 16,
including.

An arc tube 18 is connected in parallel with the series circuit of the thermally responsive switch 12 and the FECI 4, and a starting auxiliary electrode 20 of the arc tube 18 is connected to the starting resistor 16.

Since the starting device according to the illustrated example is roughly configured as described above, when a voltage is applied to the starting device via the choke coil 22 while the arc tube 18 is off, the starting device is activated via the thermally responsive switch 12. The FEC 14 then starts oscillating.

At the same time, the pulse voltage generated by the oscillation of the FECI 4 and the secondary voltage of the choke coil 22 are applied to the starting auxiliary electrode 20 via the starting resistor 16.
0 and the main electrode 24a. Therefore, a state where discharge is likely to occur between the main electrodes 24a and 24b of the arc tube 18 is established, and a discharge is started between the bipolar electrodes 24a and 24b due to the pulse oscillation by the FEC, and the arc tube 18 is lit. Note that 25 indicates an outer ball.

On the other hand, due to the heat generated by the arc tube, the thermally responsive switch 12
is heated, and the switch 12 is turned off. As a result, the oscillation of the FEC 14 is also stopped.

Note that FIG. 5(B) shows a starting device for medium to high wattage, in which a parallel circuit of a semiconductor switch 26 and a resistor 28 is connected in series with the FEC 14.

However, in the starting device shown in FIG. 5(A) and FIG. 5CB), the arc tube 18 lights up, and the heat causes the thermally responsive switch 1
Even if the OFF state of 2 continues, the starting auxiliary electrode 2
0. Since a voltage as shown in FIG. 6 is applied to the FEC 14 via the starting resistor 16, there is a problem in that deterioration of the FEC is accelerated.

Therefore, in the past, a starting device as shown in FIG. 7(A) has been developed.

The starting device shown in the figure is provided with an auxiliary electrode side thermally responsive switch 30 that corresponds to the starting resistor 16, separately from an FEC side thermally responsive switch 12 that corresponds to the FEC 14.

Therefore, once the arc tube 18 is lit, the thermally responsive switch 12.30 is turned off, and the voltage shown in FIG. 6 is no longer applied to the FEC 14.
Deterioration of C14 can also be suppressed.

Note that FIG. 7(B) shows a starting device for medium to high wattage, in which a parallel circuit of a semiconductor switch 26 and a resistor 28 is connected in series with the FEC 14.

[Problems to be Solved by the Invention] However, the starting device as shown in FIG. 7 has a problem in that although a starting pulse is generated when restarting the lamp, the lamp may not be able to be lit. there were.

In other words, while the lamp is on, the thermally responsive switch 12.30
Both are in the OFF state, but when the lamp is turned off and restarted, it is cooled down and the FEC side thermally responsive switch 12 turns ON earlier than the auxiliary electrode side thermally responsive switch 30.
The FEC 14 starts oscillating while no discharge occurs between the main electrode 24a and the starting auxiliary electrode 20. For this reason, a situation continues in which it is difficult to start a discharge between the main electrodes 24a and 24b, and although a starting pulse is generated by the FEC 14, the lamp 18 does not light up.

The present invention has been made in view of the problems of the prior art described above, and its purpose is to prevent early deterioration of FEC, restart the lamp reliably, and start a metal halide lamp that is easy to manufacture. The goal is to provide equipment.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a metal halide lamp used in the most general form, that is, a metal halide lamp with the base facing upward and the outer bulb containing the arc tube facing downward. This is a starting device for a metal halide lamp that lights up when the lamp is turned on, and includes a thermal response switch on the auxiliary electrode side that can supply current to the starting auxiliary electrode of the arc tube, and a thermal response switch on the FEC side that can supply current to the nonlinear capacitor connected in parallel to the arc tube. In the metal halide lamp starting device having a switch, the two thermally responsive switches are each made of bimetal having substantially equal contact pressure, and the FEC side thermally responsive switch is installed on the base side of the lamp. , On the other hand, the auxiliary electrode side thermally responsive switch is installed on the top side of the outer bulb.

[Function] Since the metal halide lamp starting device according to the present invention has the above-described means, a time difference occurs when the two thermally responsive switches are turned on.

In other words, when the lamp is cooled down and restarted, F
Since the EC side thermal switch is located in the high temperature area inside the lamp,
O is delayed from the auxiliary electrode side thermal response switch in the low temperature range.
It becomes N state. As a result, after a state is reached in which discharge is possible between the starting auxiliary electrode and the main electrode, generation of starting pulses by FEC is started, and the lamp is reliably restarted.

Moreover, since no voltage is applied to the FEC via the lighting auxiliary electrode during lighting, early deterioration of the FEC can be prevented.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a thermally responsive switch of the metal halide lamp starting device of the present invention. The same figure (A) is a top view, the same figure (B)
is a side view. Further, FIG. 2 shows a metal halide lamp used together with the apparatus of this embodiment. In this example, a 400W metal halide lamp was not housed in a lighting fixture, but was used in vertical lighting with the base facing upward. It should be noted that parts corresponding to the prior art described above are indicated by the reference numeral 100, and their explanation will be omitted.

FEC side thermal response switch 112. The auxiliary electrode side thermally responsive switches 130 are each made of bimetal, and both are made of the same material, have the same dimensions, and have the same contact pressure.

In this embodiment, the two thermally responsive switches 112 and 130 are installed on the alumina substrate 150, and the FEC side thermally responsive switch 112 is placed on the base 1, which is the high temperature area of the lamp.
40 side, the auxiliary electrode side thermally responsive switch 130 is installed on the top side of the outer bulb 125, which is the low temperature region of the lamp. By doing so, the FEC side thermally responsive switch 112 can be turned on later than the auxiliary electrode side thermally responsive switch 130 when restarting the lamp by utilizing the temperature difference within the lamp.

FIG. 3 shows temperature changes of the FEC side thermally responsive switch 112 and the auxiliary electrode side thermally responsive switch 13o after the lamps are turned off.

As is clear from the figure, due to the temperature difference that the base 140 side of the lamp is higher than the top side of the outer bulb 125, the FEC side thermally responsive switch 112 disposed on the base 140 side The temperature decreases later than that of the auxiliary electrode-side thermally responsive switch 130 disposed on the side. Therefore, since the thermally responsive switches 112 and 130 are configured with the same contact pressure, the auxiliary electrode side thermally responsive switch 130, which lowers the temperature to a predetermined temperature first, turns on earlier.

FIG. 4 shows a conventional circuit in which two thermally responsive switches having the above configuration are used as they are.

When restarting the lamp, the FEC side thermal response switch 112 is turned on later than the auxiliary electrode side thermal response switch 130, so first, after a state in which discharge is possible between the main electrode 124a and the starting auxiliary electrode 120 is reached. , the FEC side thermal response switch 112 is turned on and a pulse necessary for starting the lamp is generated, so that the main electrode 124a and the starting auxiliary electrode 120
The discharge starts between the main electrodes 124a, and then the discharge starts between the main electrodes 124a,
124b, the lamp can be reliably lit.

Moreover, unnecessary pulse generation in FEC114 can be prevented,
Moreover, when the FEC side thermally responsive switch 112 is OFF, the auxiliary electrode side thermally responsive switch 130 is always OFF, so the FEC side thermally responsive switch 130 is always OFF.
No voltage is applied to the EC 114 via the starting resistor 116, and early deterioration of the FEC 114 can be prevented.

Next, the specific configuration of the two thermally responsive switches 112 and 130 will be described.

9 10- When designing the two thermally responsive switches 112 and 130, it is necessary to satisfy the following conditions due to the characteristics of the lamp.

■The time it takes to turn off the power while the lamp is on, then turn it on immediately until the lamp starts (lights up) is called the restart time, but if the lamp is lit without any wind, at 30°C
Under these conditions, the restart time must be less than 15 minutes.

(2) Due to the characteristics of the FEC element, the pulse generation start temperature of the FEC 114 is preferably 70°C or lower, ideally 50°C or lower.

Additionally, the following properties are well known:

(i) The contact pressure of the bimetal contacts when the lamp is turned off changes by about ±5 g over the life of the lamp.

(ii) Variation in contact pressure during bimetal manufacturing is ±5
It is about g.

(Lit) The contact pressure P [kg
] is determined by the following formula.

P=kTE b t k: curvature constant.

E: elastic modulus.

t: Thickness.

2/4L T: Temperature change.

b1 Width L: Length The following thermally responsive switch was designed based on the conditions (1) to (3) and characteristics (i) to (iii) described above. Its structure is shown in FIG. Furthermore, the bimetal used has the following characteristics.

Curvature constant (k) -1,18X 10-5 ['C-'
] Elastic modulus (E) = 1,70X10' [kg/mm
] Width (b) = 4.0 [mm] Thickness (t) = 0.25 [mm] Effective length (L) = 15 [mm'] Considering characteristics (i) and (ii), both switches 11
The contact pressure range of 2°130 is 23g to 43g based on 33g.

In the above-mentioned range, due to the equation of characteristic (iii) and the temperature change shown in FIG. must be turned on within 15 minutes and the FEC side thermal response switch 112 must be at 70°.
It is understood that the ON operation occurs below C. Therefore, conditions ■ and ■ are cleared.

Two thermally responsive switches 112 configured as described above.
130 is incorporated into the metal halide lamp starting device 110, the auxiliary electrode side thermally responsive switch 13 is activated when restarting the lamp.
Since the FEC side thermal response switch 112 is turned ON with a delay from 0, a starting pulse is generated while a discharge is occurring between the starting auxiliary electrode 120 and the main electrode 124a, and the starting pulse is generated between the main electrodes 124a and 124b. Discharge is ensured, making it possible to reliably light the lamp. Further, for the same reason, pulse generation can be performed at a temperature of 70° C. or lower, which is appropriate for the FEC, without placing an extra load on the FEC, thereby preventing early deterioration of the FEC.

Further, in the present invention, the same parts can be used for the FEC side thermally responsive switch 112 and the auxiliary electrode side thermally responsive switch 130, making it possible to manufacture a metal halide lamp starting device simply, quickly, and more accurately.

In this example, the circuit configuration shown in FIG. It can also be applied to circuits connected to

In addition, in the case of a metal halide lamp that is used in a special configuration with the base 140 facing down and the outer bulb 125 facing upward, the auxiliary electrode side thermally responsive switch 130 and the FEC side thermally responsive switch 112 are The present invention can be applied by installing it in the opposite position.

[Effects of the Invention] As explained above, according to the metal halide lamp starting device according to the present invention, the FEC-side thermally responsive switch composed of a bimetal with the same contact pressure is placed on the base side of the lamp and on the auxiliary side. Since the electrode side thermal response switch is installed on the top side, there is a time difference between the 0N10FF operation of both, and the starting pulse is applied while a discharge is occurring between the starting auxiliary electrode and the main electrode, ensuring reliable lamp restart. It is possible to start.

Further, since no extra load is applied to the FEC, early deterioration of the FEC can be prevented.

Furthermore, since the automatic response switch is the same component, manufacturing can be simplified.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of two thermally responsive switches of a metal halide lamp starting device according to the present invention, and FIG.
is a top view, (B) is a side view, Fig. 2 is an explanatory diagram of a metal halide lamp using the device of the present invention, and Fig. 3 is a lamp diagram of a thermally responsive switch on the FEC side and a thermally responsive switch on the auxiliary electrode side. An explanatory diagram showing the temperature change after the light is turned off, FIG. 4 is a circuit diagram of an embodiment of the present invention, FIG. 5 (A) is a circuit diagram of a conventional starting device, and FIG. A circuit diagram of a starting device for medium and high wattage; FIG. 6 is a waveform diagram of the voltage applied to a conventional FEC; FIG. 7 (A) is a circuit diagram of another conventional starting device;
Figure (B) is a circuit diagram of the starting device for medium and high wattage. 12.11 14 11 20.12 25.12 30.13 4 2...FEC side thermal response switch, 4...FEC. 0...Starting auxiliary electrode, 5...Outer bulb, 0...Auxiliary electrode side thermal response switch, 0...Base.

Claims (1)

[Claims] (1) A starting device housed in the outer bulb of a metal halide lamp that is lit with the base facing upward and the outer bulb housing the arc tube facing downward, and capable of supplying current to the starting auxiliary electrode of the arc tube. In a metal halide lamp starting device having an auxiliary electrode side thermally responsive switch and an FEC side thermally responsive switch capable of supplying current to a nonlinear capacitor connected in parallel to the arc tube, the two thermally responsive switches each have a contact pressure of 1. A metal halide lamp starting device comprising substantially equal bimetals, wherein the FEC side thermally responsive switch is installed on the base side of the lamp, and the auxiliary electrode side thermally responsive switch is installed on the top side of the outer bulb.