JPS5894749A - High pressure discharge lamp starter - Google Patents

Abstract

PURPOSE:To make a discharge lamp possible to start up more speedier and steadier, by connecting in parallel with a starting circuit a pulse voltage control circuit consisting of a resistance and a switching element operated with such voltage as lower than starting voltage of the discharge lamp on the one hand and as higher than secondary no-load voltage of a ballast on the other hand. CONSTITUTION:A pulse voltage control circuit 19 consisting of a resistance 18 and a switching element 17 operated with such voltage as lower than discharge lamp's starting voltage on the one hand and as higher than ballast's secondary no-load voltage on the other hand, besides carrying immediate movability to a high frequency, is connected in parallel with a luminous tube 13. A wave of pulse voltage produced by connecting the resistance 18 via the switching element 17 in parallel with a starting circuit 16 like this is low in its maximum value Vp put a saw tooth pulse pat (a) is very little and yet a fundamental wave part (b) comes to be like a damped oscillating waveform whereby the pulse width becomes expanded so that pulse energy results in making a much contribution to the start-up of a discharge lamp effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a starting device for starting and lighting a discharge lamp.

As an example of a device for starting a high-pressure discharge lamp such as a high-voltage Nato IJ Umlang, which has a high starting voltage and is difficult to start with normal commercial power supply voltage, an inductive ballast such as a choke coil ( (hereinafter referred to as ballast)
It is known that a starting port 186 consisting of a series circuit of a resistor 4 such as an incandescent filament and a bimetal switch 5 is connected in parallel to the arc tube 3 of a high-pressure discharge lamp which is connected to an AC power source 2 via a line 1. Such a device uses an independent starting device by housing the starting circuit 6 together with the arc tube 3 inside the outer bulb 7 of the discharge lamp, and allows the high-pressure discharge lamp to be used with an existing ballast. It has become rapidly popular recently because it can be connected and used as is.

The operation of such a starting device is described in, for example, Japanese Patent Application Laid-Open No. 52-6
Although it is already known as it is described in Japanese Patent No. 7174, it will be briefly explained here in order to facilitate understanding of the present invention.

First, when the AC power source 2 is turned on, current flows through the ballast 1 to the starting circuit 6, heating the bimetal switch 5 and opening it. When the bimetal switch 5 opens, the current flowing through the ballast 1 is rapidly cut off, and a high pulse voltage is generated in the winding of the ballast 1 due to a back electromotive force. on the other hand,
When the bimetal switch 5 is opened, the heating current in the bimetal switch 5 also stops flowing, so the opening/closing contacts of the bimetal switch 5 return to their original state and the same operation is repeated again. As the bimetal switch 5 repeats opening and closing in this manner, an appropriate number of pulse voltages are applied to the electrodes of the arc tube 3 together with the power supply voltage, and the high-pressure discharge lamp is started. As the discharge lamp starts and reaches a stable state, the amount of heat radiated from the arc tube 3 increases, so that the bimetal switch 5 is kept open. In this device, the resistor 4 of the starting circuit 6 is used to limit the current flowing through the starting circuit 6, and has the following important functions.

First, if the resistor 4 is not inserted in the starting circuit 6, a large current close to the short circuit current of the ballast 1 will flow through the entire starting circuit 6, so when the bimetal switch 5 opens, several kV will be generated. An extremely high pulse voltage exceeding
The insulation of ballasts and wiring circuits may be destroyed.

Secondly, the bimetal switch 5 is used when starting the discharge lamp.
is repeatedly opened and closed, and even if a discharge starts between the electrodes of the arc tube due to one of the plurality of pulse voltages generated, when the opening and closing contacts of the bimetal switch 5 return to their original state, a resistor is inserted into the starting circuit. Without it, the current from the discharge lamp would flow into the starting circuit, causing the discharge lamp to go out.

1. In such a device, the resistor 4 of the starting circuit 6
By appropriately selecting the value of , the height of the pulse voltage is controlled and the discharge lamp is prevented from going out.

However, the above-mentioned starting device has the following drawbacks. In other words, when a commonly used commercial AC power source is used as a power source, the instantaneous value of the current when the bimetal switch is opened varies each time, and the opening speed of the bimetal switch and the arc state between the opening and closing contacts are not constant. As a result, there are variations in the height and shape of the generated pulse voltage, and stable operation cannot be expected.

For example, in the circuit configuration shown in FIG.
A 360W high-pressure Nato IJum lamp arc tube 3 is connected to an AC power supply 2 of 0■ via a choke coil type ballast 1 of about 120 mH, and a special 200 mH non-lighting lamp is connected in parallel with the arc tube 3.
Distribution state of the maximum value of pulse voltage when a starting circuit 6 consisting of an incandescent filament resistor 4 having a resistance value of Ω and a bimetal switch 5 is connected and the bimetal switch 5'i of the starting circuit is opened and closed 150 times. As shown in Figure 2, it was found that there was variation over a fairly wide range from about 1 kV at the low end to about 5 kV at the high end. If the spread is not increased enough, sufficient starting performance cannot be ensured, but this inevitably results in the generation of a high pulse voltage. In order to simply prevent high pulse voltage from being output, it is possible to -adjust the resistance value of the resistor 4 of the starting circuit 6 -move the center value of the pulse voltage distribution to a lower side; If this is done, the probability of starting the discharge lamp in the device is also low. In other words, in this type of device, if one attempts to maintain the starting probability to a certain standard, it is possible to completely prevent the generation of unnecessarily high Noculus lightning pressure to some extent, and the problem is how to prevent this.

As a means for absorbing an unnecessarily high pulse voltage, for example, as described in Japanese Patent Application Laid-Open No. 53-103668, it is possible to It has been proposed to connect a detonator for absorbing pulse voltage that operates at a voltage higher than the discharge starting voltage of (Since the pulse width of the pulse voltage is extremely short at approximately 1 μs, it was not only difficult to find a suitable discharge tube to absorb the pulse voltage in response to deviations, but also - The instability of the operation caused by the fluctuation could not be resolved at all. - As a means to remove the fluctuation in the voltage, for example, as described in Japanese Patent Laid-Open No. 143771/1980, the method shown in Fig. 1 It has been proposed to fill the inside of the outer bulb 7 that houses the starting circuit 6 with a gas that reduces the voltage generated when the /J image switch 5 is operated. The purpose is to suppress the generation of voltage.
It has been confirmed that although the overall pulse height of the pulse voltage is low, there are few high frequency components and the pulse width is wide, providing stable starting performance. However, the biggest drawback of this method is that it is not only difficult to manufacture because a certain amount of gas must be sealed inside the outer bulb, but also impurity gas is released from the arc tube and its supporting structure during use.
The problem is that stable performance cannot be maintained.

The present invention was developed as a result of detailed research into the relationship between the starting conditions of high-pressure discharge lamps and the pulse voltage waveform based on the above-mentioned background. It is an object of the present invention to provide a starting device that generates an unnecessarily high pulse voltage that can suppress the generation of a pulse voltage that is higher than necessary, and can start a discharge lamp quickly and stably.

The present invention will be explained in detail below. FIG. 3 shows the relationship between the dielectric breakdown voltage, that is, the starting starting voltage, and the half-value of the applied or russian voltage in a 360 W high-pressure sodium lamp with a built-in starting circuit.

As is clear from this figure, it can be seen that the smaller the A pulse width, the higher the starting voltage of the discharge lamp. Conversely, if the pulse width is increased, the starting voltage of the discharge lamp will be lowered, which will not only allow starting with a lower voltage, but also reduce the effect on the ballast and wiring circuit. However, as shown in Fig. 4, in the waveform of the pulse voltage in the conventional starting device as described above, the sawtooth liquid part (a), which has a short pulse width and a relatively high absolute value, occupies most of the waveform. ,
Finally, a slightly wider sine wave section (b) appears.

The pulse voltage of the saw liquid part (a), which occupies the majority, has a narrow width of 2 μs or less, so unless the peak value is 4 to 5 KV or more, it is not sufficient to start the discharge lamp, and the discharge lamp may not start. Even if it starts, it often remains unabsorbed. That is, with conventional starting systems, inherently high ie and smear pressures occur. The present invention is a novel method that suppresses the generation of the sawtooth waveform norus as described above, and performs waveform conversion that lowers the maximum value and widens the norus width, thereby making it extremely easy and stable to start a discharge lamp. This provides an effective starting device.

FIG. 5 shows an embodiment of a starting device for a high pressure discharge lamp according to the present invention. In the figure, 11 is an AC power supply, 12 is a ballast, and 13 is a high-pressure discharge lamp arc tube, which are connected in series to form a lighting maintenance circuit for the discharge lamp. Further, 14 is a resistor such as an incandescent filament, and 15 is a resistor such as an incandescent filament.
are bimetal switches, and a series circuit of these is connected in parallel with the arc tube 13 to form a starting circuit 16. The present invention provides a starting device having such a circuit configuration, which discharges electricity in parallel with the arc tube 13, operates at a voltage lower than the starting voltage of the lamp and higher than the secondary no-load voltage of the ballast, and has immediate action against high frequencies. A voltage control circuit 19 consisting of a switching element 17 and a resistor 18 is connected thereto. As shown in FIG. 6, the waveform of the voltage generated by connecting the resistor 18 in parallel with the arc tube 13 and the starting circuit 16 via the switching element 17 has a maximum value V, although it is low. , the sawtooth liquid part (a) is extremely small and the fundamental wave part (b) has a damped oscillatory waveform, so that the lasing width expands and the lasing energy effectively contributes to starting the discharge lamp. become.・The reason why the width of the gusset voltage increases can be explained by the fact that the vibration condition changes from an oscillating one to a damping one due to an increase in the R component of the LCR circuit in the equivalent circuit of the ballast. It is inferred that the insertion of the bimetal switch lowers the peak value of the S/P pulse voltage, which reduces the amount of saw liquid due to a slight discharge at the opening/closing contact when the bimetal switch is opened.

As described above, in the starting device according to the present invention, the peak value of the signal voltage is suppressed and the uncertain element of partial electrification of the opening/closing contacts of the bimetal switch is almost completely eliminated. If the fluctuation is small, the distribution state of the maximum value of the pulse voltage will be as shown in FIG.

As is clear from the figure, no unnecessarily high voltage of about 4 to 5 KV is generated, and the safety for the ballast and wiring circuit is extremely high. Moreover, since the pulse width of the gust voltage is widened, starting performance is not impaired. As mentioned earlier, Figure 3 shows the relationship between the starting voltage and the half-width of the applied pulse voltage for a 360W high-pressure sodium lamp. This is more advantageous for starting.

The resistance value of the resistor 18 of the starting circuit 19 is determined based on the relationship between the distribution state of the maximum value of the bus voltage and the startability of the discharge lamp. When the resistance value is increased, the waveform becomes oscillatory and contains many high-frequency components, the halus height also increases, and the gusset width becomes narrower. When the resistance value is decreased, the opposite phenomenon occurs. 50 to 500 with a 200V commercial AC power supply
180-980 via mH choke coil type ballast
When starting a W high pressure sodium lamp, the resistance value of the resistor 18 is selected within the range of 1 to IOKΩ.

The effect of the present invention on starting performance can also be confirmed by comparing FIG. 2 and FIG. 7.

That is, assuming that the starting voltage of the discharge lamp is 2.5 KV, the probability that a voltage of 2.5 KV or more will occur in the conventional starting device is 2.5 for the total number of occurrences in Figure 2. When calculated as the number of occurrences of Noyals voltage equal to or higher than KV, it is 0.5. Similarly, in the starting device of the present invention, the probability that a voltage of 2.5 KV or more will occur is 0.5, which is the same as in the prior art. Nevertheless, the maximum value of the bus pulse voltage is suppressed to 3.8 KV in the present invention, whereas it is 5 KV in the conventional case. That is, assuming that the discharge lamps have the same starting ability, the starting device according to the present invention can somewhat reduce the maximum value of the Luss voltage. On the other hand, if the maximum values are kept the same, starting performance can be improved.

Next, in the present invention, in series with the resistor 18 of the starting circuit 19, the starting voltage is lower than the starting voltage of the discharge lamp, the ballast 120 operates at a voltage higher than the secondary no-load voltage, and is quick-acting against high frequencies. It is characterized in that a switching element 17 is connected.

If such a switching element is not inserted, the resistor 18
is connected in parallel with the arc tube 13, so a steady current flows through the resistor 18 when the ballast 12 is under no load and when the discharge lamp is lit. In this case, if the resistance value of the resistor 18 is 3Ω, the power consumed by the resistor 18 is w
=v2/R=20r3X10'=13.3CW:]. However, it is impractical to incorporate such a high-power, large-sized resistor into the outer bulb of a discharge lamp or to use it while storing it in an external case.

The switching voltage of the switching element 17 should be selected to be sufficiently high so that it does not operate at the secondary no-load voltage of the ballast 12, and within a range that does not exceed the starting voltage value of the discharge lamp. If this value is too high, there will be fewer opportunities for the resistor 18 to work, and waveform conversion will not be performed, making it impossible to obtain the effects of the present invention. Also, /-? The discharge delay must be less than lμl in order to act quickly enough on the bus pulse voltage including high frequency components generated by the operation of the innotal switch 15. A micro-gap creeping discharge tube was found to be suitable after selecting and examining various switching elements. Such a discharge tube is described in detail in, for example, Japanese Unexamined Patent Publication No. 52-6956, and since the dielectric breakdown mechanism is based on field emission, the discharge delay is small, 0.1 μ8 or less, and it is sufficiently fast even at high frequencies. It is something that moves. In the present invention, the operating voltage of the switching element is, for example, 500 to 15
If you select 00V, the stabilizer will often operate due to the secondary no-load voltage, so the resistor 18 has a constant power IKW.
The following small sizes can be used: However, it is desirable that the resistor 18 has a withstand voltage of about 6 KV or higher with respect to the voltage 7 or the Leus voltage.

A carbon film resistor of about 1/2 to 1 watt can be cited as one that satisfies this requirement. The resistor has a relatively small temperature coefficient of resistance, is stable in a high-temperature vacuum or gas atmosphere, and can be used by being incorporated inside the outer bulb of a discharge lamp. Furthermore, the microgap type creeping discharge tube described above can also be used by being incorporated into a discharge lamp. In the above embodiment, an incandescent filament was used as the resistor 14 of the starting circuit 16, and a carbon film resistor was used as the resistor 18 of the positive voltage control circuit 19. For example, it may be replaced by a metal thick film resistor deposited on a ceramic substrate. Also,
As shown in Figure 8, the voltage control circuit 19 is connected to the starting circuit 1.
6 may be connected in parallel with the bimetal switch 15, or as shown in FIG. 9, the positive voltage control circuit 19 and, if necessary, the starting circuit 15 may be connected to the outside of the discharge lamp.

If these are installed externally without being incorporated into the discharge lamp,
At least 10,000 of the resistors 14 or 18 may be variable resistors in order to adjust the pulse voltage, the pulse height, and the like. Furthermore, as shown in FIG. 10, it is also possible to use a semiconductor element such as a two-terminal thyristor as the switching element 17 of the bus voltage control circuit 19.

As described above, the present invention relates to a starting circuit consisting of a series circuit of a resistor and a bimetallic switch connected in parallel to the arc tube of a high-pressure discharge lamp connected in series with a ballast. A series circuit consisting of a switching element and a resistor that operates at a voltage lower than the starting voltage of the discharge lamp and higher than the secondary no-load voltage of the ballast and that is responsive to high frequencies is connected in parallel with the switch or ballast. However, if we focus only on the point that a series circuit of a switching element such as a resistor and a discharge gap is connected in parallel with a bimetal switch, a similar circuit as described in Utility Model Application No. 56-4198, for example, can be found. Starting devices are known. However, this device consists of a series circuit consisting of a resistor and a discharge gap that operates at a voltage higher than the starting voltage of the discharge lamp, instead of a resistor connected in series with the bimetallic switch in the starting circuit. The purpose of this is to connect the voltage to the current, and the purpose is not to convert the waveform of the nofrus voltage, and no resistor is inserted in the starting circuit. In such a configuration, even if the discharge lamp is once lit due to the generation of pulse voltage accompanying the opening and closing of the bimetal switch, there is a risk that when the bimetal switch returns, the discharge lamp that has already been lit may be short-circuited and extinguished. .

In addition, since a large current close to the secondary short-circuit current of the ballast is cut off by a bimetal switch, a voltage that rises extremely quickly and has a large amount of energy is generated, so in practice, a voltage absorption circuit is not required. Even if it is provided, it is difficult to control the Norsumi pressure to an appropriate value. In other words, the present invention achieves technical effects that cannot be achieved with such prior art, and is clearly distinguishable from the same prior art.

Finally, the effects of the present invention will be described.

First, as mentioned above, although the voltage generated by the starting device according to the present invention has a low voltage, the voltage has a wide voltage range, which reduces the ability to start the discharge lamp. Therefore, the maximum value of Hals voltage can be reduced overall. The lower maximum value increases the safety of the ballast and wiring circuit. Furthermore, since the waveform of the pulse voltage is stable with a small amount of liquid, the discharge lamp can be started efficiently and stably. Furthermore, the starting circuit is a two-terminal circuit consisting of a resistor and a metal switch, and the voltage control circuit is also a two-terminal circuit consisting of a resistor and a switching element, and the elements that make up these are each heat resistant. Since one can be selected, both circuits can be easily integrated into the outer bulb together with the arc tube of the discharge lamp. In addition, by appropriately selecting the resistance value of the resistor in the starting circuit and the positive voltage control circuit,
Since the height of the signal voltage can be changed arbitrarily, the degree of freedom in designing the device increases.

Although other reasons are unknown, in the starting device according to the present invention, there is a tendency for the opening and closing operations of the bimetallic switch in the starting circuit to increase, which generates a large number of voltages, making it easier to start the discharge lamp. There are also advantages.

As described above, the high-pressure discharge lamp starting device according to the present invention has various advantages compared to conventionally known starting devices of this type, and has great industrial utility value.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a conventional high-pressure discharge lamp starting device, Fig. 2 is a distribution diagram of the maximum value of cell pressure in the same device, and Fig. 3 is a diagram showing the starting voltage of a discharge lamp in this type of starting device.
FIG. 4 is a curve diagram showing the relationship between the half-width of the cell pressure. FIG. 4 is a waveform diagram of the voltage of the conventional starting device. FIG. 5 is a circuit diagram of an example of the starting device according to the present invention. The figure is a waveform diagram of the voltage of the starting device, FIG. 7 is a distribution diagram of the maximum value of the voltage of the starting device in the same device, and FIGS. 8 to 10 are diagrams of other embodiments of the starting device of the present invention. It is a circuit diagram. In FIG. 5, 11... AC power supply, 12... Ballast, 13... Arc tube, 14... Resistor, 15...
Bimetal switch, 16... Starting circuit, 17...
Switching element, 18...Resistor, 19...Regulus voltage control circuit. , 1-1 Figure No.

Claims (1)

[Scope of Claims] (1) A high-pressure discharge lamp comprising an arc tube of a high-pressure discharge lamp connected in series with an inductive ballast, and a starting circuit consisting of a series circuit of a resistor and a bimetal switch, or a starting circuit connected in parallel. In the starting device, the starting circuit or the bimetal switch of the starting circuit or the ballast is operated at a voltage lower than the starting voltage of the discharge lamp and higher than the secondary no-load voltage of the ballast, and is resistant to high frequencies. A starting device for a high-pressure discharge lamp, characterized in that a pulse voltage control circuit consisting of a series circuit of a quick-acting switching element and a resistor is connected. (2) The starting device for a high pressure discharge lamp according to claim 1, wherein the resistor of the starting circuit is an incandescent filament, and the resistor of the pulse voltage control circuit is a carbon film resistor. (3) The starting device for a high-pressure discharge lamp according to claim 1, wherein the resistor of the starting circuit and the resistor of the pulse voltage control circuit are both metal thick film resistors. (4) The starting circuit and the pulse voltage control circuit are both housed inside the outer bulb of the high-pressure discharge lamp, which has a built-in arc tube. Starting device for high pressure discharge lamps. (5) Starting circuit mechanical and pulse voltage control circuit (6)
2. The high-pressure discharge lamp starting device according to claim 1, wherein the switching element of the pulse voltage control circuit is a micro-gap discharge lamp. (7) Claim 1, characterized in that the switching element of the pulse voltage control circuit is a two-terminal thyristor.
A starting device for a high pressure discharge lamp as described in . (8) The high-pressure discharge lamp starting device according to claim 1, wherein the high-pressure discharge lamp connected in series with the ballast is a high-pressure sodium lamp.