JP2830169B2 - Metal vapor discharge lamp starting device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an apparatus for starting a metal vapor discharge lamp, and more particularly to an improvement in a thermally responsive switch thereof.

[Prior art] Metal vapor discharge lamps, especially metal halide lamps, have a spectrum over the entire visible region, have excellent color rendering properties, and have good luminous efficiency, so they are widely used in lighting fields such as sports and commercial facilities. Have been.

By the way, since it is difficult to start the metal halide lamp with a commercial power supply voltage, a starting device having a configuration as shown in FIG. 6 has been conventionally used.

First, the starting device shown in FIG.
And a non-linear capacitor (hereinafter referred to as FEC) 14 connected in series with the switch 12.

An arc tube 16 is connected in parallel with the series circuit of the thermally responsive switch 12 and the FEC 14.

Since the starting device according to the illustrated example is configured as described above, when a lighting current is supplied to the starting device 10 via the choke coil 18 in a state where the arc tube 16 is turned off,
A voltage is applied to the starting circuit of the FEC 14 via the thermoresponsive switch 12. For this applied voltage, a non-linear change in the capacitance of the capacitor is expressed as V _p = −
A pulse voltage represented by Ldi / dt is generated, and the lamp starts (Japanese Patent Publication No. 48-28726).

FIG. 7 shows a circuit in which the starting resistor 20 and the starting auxiliary electrode 22 in the arc tube 16 in the circuit of FIG. 6 are provided. Due to the starting auxiliary electrode 22, the discharge between the main electrodes 24a and 24b of the arc tube 16 is more likely to occur than in the circuit shown in FIG. 6, and the pulse oscillation by the FEC 14 causes the discharge between the two main electrodes 24a and 24b. Then, discharge starts, and the arc tube 16 lights up.

When the lamp is turned on (when the lamp is stable), the thermoresponsive switch 12 is heated, so that the switch 12 is turned off. As a result, the oscillation of the FEC 14 is also stopped.

In addition, a starting device as shown in FIG. 8 has been developed.

The starting device 10 shown in FIG. 1 is provided with an auxiliary electrode side thermally responsive switch 26 corresponding to the starting resistor 20 separately from the FEC side thermally responsive switch 12 corresponding to the FEC 14.

[Problems to be Solved by the Invention] However, in the starting device shown in FIG. 7, the following defects were observed when the lamp was turned on for a long time.

That is, the voltage shown in FIG. 9 is continuously applied to the FEC 14 via the main electrode 24b and the starting auxiliary electrode 22 while the lamp is turned on (when the lamp is stable).

Generally, the temperature of FEC14 during lamp operation is about 300 ° C when installed near the neck of the lamp, which is higher than the Curie temperature of FEC14 (about 90 ° C in this case). And the capacity also decreases. As a result, the impedance is increased, and the voltage between the terminals of the FEC 14 is also increased to a peak value of about 100 V or more as shown in FIG.

As described above, when a high voltage is applied for a long time in a high temperature state, the silver of the silver electrode of the FEC 14 diffuses (migrate) along the crystal grain boundaries, and as a result, the nonlinearity of the FEC 14 deteriorates. , Not only causes a drop in pulse voltage,
Destruction may be caused by a decrease in insulation resistance. According to the experiment, when mounted on a 400 W lamp, the phenomenon that the FEC was destroyed by the generated pulse occurred due to the deterioration of the insulation resistance of the FEC after about 1000 to 2000 hours of lighting.

On the other hand, in the starting device shown in FIG.
When is turned on, both of the thermoresponsive switches 12 and 26 are turned off, no wasteful voltage is applied to the FEC 14, and the deterioration of the FEC 14 can be suppressed. However, there has been a problem that the lamp cannot be turned on when the lamp is restarted.

That is, while the lamp is turned on, both the thermoresponsive switches 12 and 26 are in the OFF state, but when the lamp is turned off / relighted, the heat is cooled and the FEC side thermoresponsive switch 12 is turned on earlier than the auxiliary electrode side thermoresponsive switch 26. When the discharge occurs, the discharge between the main electrode 24a and the starting auxiliary
C14 starts oscillating. For this reason, the state where it is difficult to start the discharge continues between the main electrodes 24a and 24b, and although the start pulse is generated by the FEC 14, the lap 18 does not light up.

Furthermore, if the above-mentioned voltage is continuously applied due to the temperature characteristics of FEC14, the pulse voltage will be reduced due to self-heating (see IES of Australia'88, the theory), making it more difficult to restart the lamp. was there.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a metal vapor discharge lamp starting device capable of preventing early deterioration of FEC and reliably restarting a lamp. Is to do.

Means for Solving the Problems To achieve the above object, a metal vapor discharge lamp starting device according to the present invention includes a starting auxiliary electrode and a common contact connected to a nonlinear capacitor, and a main electrode on the starting auxiliary electrode side. It has a normal-temperature open contact connected, and a normal-temperature closed contact connected to the main electrode on the non-start auxiliary electrode side.When the lamp is started, the common contact contacts the normal-temperature closed contact, and when the lamp is lit, the common contact A heat responsive switch for short-circuiting the starting auxiliary electrode and the main electrode on the side of the starting auxiliary electrode by contacting a normal temperature open contact is provided.

[Operation] Since the metal vapor discharge lamp starting device according to the present invention includes the above-described means, since the temperature is high during lamp operation, the common contact of the thermally responsive switch is in contact with the normal temperature open (high temperature closed) contact. Since the main electrode on the side of the starting auxiliary electrode and the starting auxiliary electrode are in a short-circuit state, no unnecessary voltage is applied to the FEC.

In addition, when the lamp is restarted, the thermal responsive switch contacts the contact that is open at normal temperature after the common contact comes into contact with the normal-temperature closed (high-temperature open) contact and the discharge starts and the temperature becomes high again. I can do it reliably.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

First Embodiment FIG. 1 shows a basic embodiment of the present invention. It should be noted that the parts corresponding to those of the above-mentioned conventional technique are indicated by the reference numeral 100, and the description is omitted.

In this embodiment, an arc tube of a 125 W metal halide lamp is used.
A thermoresponsive switch 130 having a contact 116 that is normally closed (hereinafter referred to as an NC contact) 132a, a contact that is normally opened (hereinafter referred to as an NO contact) 132b, and an agreement contact (hereinafter referred to as a COM contact) is provided. .

The NC contact 132a is connected to the main electrode 124a of the arc tube 116,
The O contact 132b is connected to the main electrode 124b on the starting auxiliary electrode 122 side. The COM switch 132 of the thermally responsive switch 130 is divided into two directions. One is connected to a starting auxiliary electrode 122 via a starting resistor 120, and the other is connected to a main electrode 124 via a FEC 114.
Connected to b.

In this embodiment, FEC114 is made of barium titanate (BaTi
O ₃ ) is a non-linear capacitor with a diameter of 15.5m
A silver film electrode having a diameter of 14.5 mm is formed on a sintered substrate having a thickness of 1.0 mm and a thickness of 1.0 mm, and an electrode terminal is provided on a silver film electrode overcoated with inorganic glass.

The FEC 114 has a Curie point of about 90 ° C. and can withstand a temperature of 400 ° C. and temporarily 550 ° C. temporarily so that it can be installed in a lamp.

In the circuit shown in the figure, when the lamp is started, the thermally responsive switch 130 is in contact with the NC contact 132a around the COM contact 132c, and a voltage is applied to the FEC 114 via the NC contact 132a, as shown in FIG. A pulse is generated, and the pulse is applied between the starting auxiliary electrode 122 and the main electrode 124b and between the main electrodes 124a and 124b via the starting resistor 120. Fig. 2 shows 125
It is a waveform diagram at the time of using in combination with the choke coil type ballast of W / 240V.

Then, about 2-3 minutes after the light emitting tube 116 is turned on, the thermoresponsive switch 130 is switched by the rise in temperature, and the COM contact 13
2c contacts NO contact 132b. Accordingly, when the lamp is stably lit (hot), the main electrode 124b and the starting auxiliary electrode 122 are short-circuited via the starting resistor 120, so that no voltage is applied to the FEC 114, and early deterioration of the FEC 114 can be prevented.

Further, in this circuit, since there is no potential difference between the main electrode 124b and the starting auxiliary electrode 122 during lamp operation, it is possible to prevent the seal portion from being damaged due to the electrolytic phenomenon between the two electrodes, which is peculiar to the metal halide lamp. Migration of silver of the silver film electrode due to the above can be prevented.

When the lamp is restarted, the heat responsive switch 130
Always contacts the NC contact 132a after leaving the NO contact 132b,
Since a voltage is applied to both the FEC 114 and the starting auxiliary electrode 122 at the same time, there is no useless pulse generation and there is no pulse voltage drop due to self-heating during pulse generation, so that a stable lamp restart can be obtained.

Second Embodiment FIG. 3 shows a device according to a second embodiment of the present invention. In addition, the part corresponding to the above-mentioned conventional technology is shown by adding reference numeral 200,
Description is omitted.

The figure shows a starting device suitable for medium to high wattage, FE
A semiconductor switch 240 is connected in parallel with C214.

For a 400W metal halide lamp, the semiconductor switch 24
The breakover voltage V _bo of 0 is suitably 100 to 220 V, and the pulse voltage is 1000 to 2000 V.

In general, the semiconductor switch 240 is held in a base and can withstand a storage temperature sufficiently.

Third Embodiment FIG. 4 shows a device according to a third embodiment of the present invention. In addition, the part corresponding to the prior art is indicated by adding reference numeral 300,
Description is omitted.

The device shown in the figure can stabilize the ON phase of the semiconductor switch 340 by providing a resistance 350 of 10 to 200 KΩ in parallel to the semiconductor switch of the second embodiment.

Fourth Embodiment FIG. 5 shows a fourth embodiment of the present invention. It is to be noted that reference numerals 400 are added to portions corresponding to the above-described conventional technology, and description thereof is omitted.

The device shown in the figure uses a phase-adjusted ballast in the fourth embodiment, and further adds a resistor 460 of 10 to 300 kΩ in parallel with the series circuit of the FEC and the semiconductor switch,
This serves as a discharge resistor for the series capacitor of the phase-adjusted ballast and prevents the starting circuit from being blocked by the unidirectional charging of the phase-advanced capacitor by an unbalanced current when starting the lamp.

In addition, as a result of an experiment in which the effect of the present invention was combined with the arc tube of a 400 W metal halide lamp, it was confirmed as follows.

The lamp flickered three times a day and turned on for 9000 hours, but the FEC was not damaged and gave a sufficient starting pulse,
The lamp worked reliably.

Also, the peak value of the pulse voltage was ± 1500 V at the beginning, but was ± 1200 V even after 9000 hours had elapsed, confirming that the function was sufficiently performed.

[Effect of the Invention] As described above, according to the metal vapor discharge lamp starting device according to the present invention, while the lamp is lit, the common contact of the thermally responsive switch contacts the normal temperature open contact, and the main electrode on the starting auxiliary electrode side. And the starting auxiliary electrode are short-circuited, so that early deterioration of FEC can be prevented.

When the lamp is restarted, the common contact of the thermally responsive switch contacts the normal-temperature closed contact and the luminous bulb is turned on, and then contacts the normally-open contact, so that the lamp can be reliably restarted.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention, FIG. 2 is a waveform diagram of a voltage applied when starting a lamp, FIG. 3 is a circuit diagram showing a second embodiment of the present invention, FIG. 4 is a circuit diagram showing a third embodiment of the present invention, FIG. 5 is a circuit diagram showing a fourth embodiment of the present invention, FIG. 6 is a circuit diagram showing a first conventional device, 7 is a circuit diagram showing a second conventional device, FIG. 8 is a circuit diagram showing a third conventional device, and FIG. 9 is an explanatory diagram of a problem of the conventional device shown in FIG. . 14,114,214,314,414 ... non-linear condenser, 16,116,216,316,416 ... arc tube, 22,122,222,322,422 ... start-up auxiliary electrode, 24,124,224,324,424 ... main electrode, 130,230,330,430 ... thermal switch, 132a, 232a, 332a, 432a ... NC contact, 132b, 232b, 332b, 432b …… NO contact.

Claims (1)

(57) [Claims] 1. A starting device for a metal vapor discharge lamp comprising: a metal vapor discharge lamp having a main electrode and a starting auxiliary electrode; and a non-linear capacitor capable of applying a pulse voltage between the main electrodes. And a common contact connected to the non-linear capacitor, a normal temperature open contact connected to the main electrode on the starting auxiliary electrode side, and a normal temperature closed contact connected to the main electrode on the non-starting auxiliary electrode side, and the lamp starts. When the lamp is lit, the common contact is brought into contact with the normal-temperature closed contact, and the common contact is brought into contact with the normal-temperature open contact to short-circuit the starting auxiliary electrode and the main electrode on the starting auxiliary electrode side. Metal vapor discharge lamp starting device.