JPS58169895A - Device for firing discharge lamp - 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 The present invention relates to a discharge lamp lighting device that uses a nonlinear capacitor to obtain a high pulse voltage.

An example of a conventional device of this type is the Japanese Patent Publication No. 48-28726.
What is shown in the publication No. is proposed. This device uses a non-linear capacitor to obtain a high pulse voltage, which is useful because it enables quick starting. However, in the case of hot cathode discharge lamps such as fluorescent lamps, if the lamps are started with a high pulse voltage before the electrodes have been sufficiently preheated, a so-called cold start will occur, which will shorten the life of the discharge lamp. It is. For this reason, a semiconductor switch for conducting preheating current has been proposed that conducts at an early phase of the AC power supply voltage. If so, there is a risk that conduction may occur even at the lamp voltage after the discharge lamp is started. For this reason, it is necessary to use a semiconductor switch whose conduction voltage is strictly regulated, or to use a special conduction control device.

Management is troublesome, and costs may increase.

The present invention has been made to eliminate the drawbacks of the conventional devices described above, and prevents the cold start of the discharge lamp and thereby prevents the life of the discharge lamp from deteriorating.

Another object of the present invention is to provide a discharge lamp lighting device with a simple configuration.

The present invention suppresses the amount of charge of the non-linear capacitor during a predetermined period at the beginning of the startup of the discharge lamp, thereby suppressing the generated pulse voltage, and preheating the electrodes of the discharge lamp. The present invention is characterized in that the charging amount is such that a pulse voltage sufficient for starting the discharge lamp can be obtained.Nine embodiments of the present invention will be described below with reference to FIG. 1g and FIG. 2. (1) is a power source such as a commercial power source.

(2) is a discharge lamp, such as a fluorescent lamp, energized by this electric current (11), and (3) is an inductive impedance device, such as a choke coil, provided in series with the discharge lamp (2). 4) is a non-linear capacitor developed in the 1970s.
This is a well-known device as shown in Japanese Patent No. 8-28726, etc., and is provided in parallel with the discharge lamp (2). Parallel means allowing other parts to be interposed in between. (5) is a switch device, and a diode (6)
The discharge lamp (2) is provided in parallel with the discharge lamp (2) via the discharge lamp (2). Resistance (7).

(8) is for supplying a gate signal to the switch device (5). The switching device (5) may respond to the voltage across the discharge lamp (2), or may be made conductive by a pulse voltage generated when the nonlinear capacitor (4) is saturated. Also, as a switch device (5), in addition to SCR, triac, 8BS
, 888, etc. may be used. However, as will be described later, it is necessary to conduct in only one direction, so when a bidirectional type is used, diodes are connected in series as in this embodiment. (9) is a control device that suppresses the amount of charge of the nonlinear capacitor (4) during a predetermined period at the beginning of starting the discharge lamp (2). The control device (9) in this embodiment is configured as follows.

That is, it consists of a parallel circuit of a diode aO and a nonlinear resistor αυ whose resistance value changes from high to low to high as the temperature increases from room temperature to high as shown in FIG. 2, and the nonlinear capacitor (4) It is installed in series with. The non-linear resistance al) is, for example, the switch device (5)
is thermally coupled with.

Furthermore, as shown in Fig. 2, this non-linear resistance αυ is the resistance g at room temperature (25°C).
When 8 degrees Te 1/2 K decreases and the temperature rises further beyond 60 degrees k, the resistance value increases again. Generally available commercially available products may also be used. Although the change in resistance value with respect to temperature differs depending on the 82 types, it is possible to obtain the desired characteristic Y by selecting the non-linear resistance, the heat capacity of this resistance, etc.

Next, we will discuss the effect. In this example, the nonlinear resistance aυ
What is the effect when considered as a general resistance?

For example, Special Publication No. 48-28726 2% Publication No. 48-
Since this is well known as disclosed in Japanese Patent No. 19181, a detailed explanation will be omitted, but in summary.

The switch device (5) conducts and the discharge lamp (
2), one electrode preheating current is passed through this switch device (5).
When the lamp becomes non-conductive, a high pulse voltage is generated and the discharge lamp (2
). therefore.

The high pulse voltage may force the discharge lamp (2) to start even though the electrodes of the discharge lamp (2) have not been sufficiently preheated. In contrast, since the present invention is provided with a control circuit (9), the pulse voltage at the initial stage of starting the discharge lamp (2) is low (
It is something that can be suppressed.

That is, in FIG. 1, since the non-linear resistance Qll initially exhibits a high resistance value, the amount of charge of the non-linear capacitor (4) in the polarity shown in FIG. 9 is suppressed. Therefore, the amount of change in Q at the time of charging to the next polarity becomes smaller, and the pulse voltage becomes relatively lower. Of course, the Norms voltage at this time is selected so that the discharge lamp (2) cannot be started. Next, after a predetermined period of time (in this embodiment, the ambient temperature of the place and the discharge lamp, which cannot be precisely designed because it depends on the temperature of the room and the five points), the resistance value of the nonlinear resistance aυ decreases.

Since the amount of charge in the nonlinear capacitor (4) increases compared to the previous time, the pulse voltage also becomes relatively high. Therefore, when the discharge lamp (2) starts, the electrodes are sufficiently preheated and the service life is not impaired.

Next, the experimental results of the first example will be shown.

Power supply (II: 50 Hz, 100W discharge lamp (2): 30W light lamp at room temperature (25℃) - Norms voltage is 700~5oov
(peak value), whereas the pulse voltage at 60° C. was 1200 V (peak value).

Then, the transition time from room temperature to 60°C is about 1 second,
The life of the discharge lamp (2) shall not be impaired.
[It was.

FIG. 3 shows another embodiment of the invention. The same parts as in FIG. 1 are given the same reference numerals, and their explanation will be omitted. In this embodiment, the control device (field) is used.

In place of the non-linear resistance αυ in Figure 1, use a voltage divider circuit α.

A switch C131 installed in parallel with a part of this voltage dividing circuit a3
This switch (131) is opened and closed by, for example, a timer Q4 synchronized with power-on. That is, when the power is turned on, the switch 3 is opened and closed after a predetermined period of time. Note that instead of the timer, the switch (131) may be controlled by sensing the heat of the switch device (5) or the inductive inducer device (3).This embodiment Since the action of is easily understood, the explanation will be omitted.

Note that the present invention can be modified in various ways other than the above embodiments. For example, the control device is good as long as it can control the amount of charge of the nonlinear capacitor, and is not limited to the above embodiment.

As detailed above, the present invention suppresses the amount of charge of the nonlinear capacitor for a predetermined period at the initial stage of starting the discharge lamp, thereby keeping the pulse voltage low. Therefore, it is possible to prevent deterioration of the life of the discharge lamp.

[Brief explanation of the drawing]

#! FIG. 1 is a circuit diagram showing one embodiment of the present invention, FIG. 2 is a characteristic diagram of a nonlinear resistance shown as an example, and FIG. 3 is a circuit diagram showing another embodiment of the present invention. (4)...Nonlinear capacitor, (5)...Switch device, (9), (9'')...Control device. Patent applicant: Toshiba Electric Materials Co., Ltd. Agent, Patent attorney: Yoshihiro Onoda Figure 1 Figure 2

Claims (1)

[Claims] (11) An inductive impedance device provided in series with the discharge lamp; A non-linear capacitor provided in parallel with the discharge lamp; A switch device provided in parallel with the discharge lamp A discharge lamp lighting device comprising: a control device that suppresses the amount of charge of the non-linear capacitor during a predetermined period at the beginning of starting the discharge lamp; and (2) the control device comprises a diode and a control device. It consists of a parallel circuit with a non-linear resistor whose resistance value changes from high to low to high as the temperature rises from room temperature to high temperature. The discharge lamp lighting device according to claim (1). (3) The control device includes a diode, a voltage dividing circuit connected in parallel with the diode, and a part of the voltage dividing circuit provided in parallel. A discharge lamp lighting device according to claim 1, characterized in that a switch is provided, and a parallel path of the diode and the voltage divider circuit is provided in series with the nonlinear capacitor. Device.