JPS5966098A - Device for firing fluorescent 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 Field of the Invention The present invention relates to a fluorescent lamp lighting device, and more particularly to a phase-advanced fluorescent lamp lighting device.

Configuration of conventional example and its problems The conventional phase advance type fluorescent lamp lighting device is as shown in Fig. 1.
A fluorescent pair 4 is connected to a power source 1 via a ballast consisting of an inductance element 2 and a capacitor 3 in series to form a closed circuit, and a lighting tube 6 is connected to both ends of the fluorescent pair 40. be.

Such a fast-phase fluorescent lamp lighting device has the following advantages compared to a slow-phase fluorescent lamp lighting device that uses an inductance element as a ballast.
When the power supply voltage is more than four times the lamp voltage of the fluorescent pair, the capacitor can have a voltage drop.
It has the advantages of being able to reduce the size of the inductance element, making the ballast smaller and lighter, and having good power supply voltage fluctuation characteristics.

However, the preheating current for the fluorescent pair at startup flows approximately twice as much as the lamp current in a slow-phase fluorescent lamp lighting device, but only the same amount as the lamp current flows in a fast-phase fluorescent lamp lighting device. For this reason, in phase-advancing fluorescent lamp lighting devices, the terminal voltage of the electrode filament is small and glow discharge is less likely to occur.
Poor starting characteristics, cold cathode discharge, early blackening,
There was a drawback that there were some disadvantages.

OBJECTS OF THE INVENTION The present invention was made in order to eliminate the drawbacks of such fast-phase fluorescent lamp lighting devices, and provides a fluorescent lamp lighting device that can improve starting characteristics and life characteristics. be.

Structure of the Invention The present invention is an advanced-phase fluorescent lamp lighting device in which a positive temperature coefficient thermistor is connected to both ends of a capacitor to increase the preheating current at the time of starting and improve the starting characteristics. .

DESCRIPTION OF EMBODIMENTS As shown in FIG. 2, a phase-advanced fluorescent lamp lighting device according to an embodiment of the present invention connects a series body of an inductance element 2, a capacitor 3, and a fluorescent pair 4 to a commercial power source 1. A lighting tube 6 is connected to both ends of the fluorescent pair 4, and further to both ends of the capacitor 3.

A positive temperature coefficient thermistor 6 is connected which has a low resistance when the fluorescent pair 4 is started, and a high resistance when the operation is stable, and has a function of increasing the preheating current of the fluorescent pair 4 at the time of starting.

゛The circuit constants of the above embodiment are as follows.

Commercial power supply 1: 220V, 5ollz inductance element 2: 1H Capacitor s: 2.4 μF Fluorescent pair 4: FL10 Lighting tube 5: FG-4P Positive characteristic thermistor 6: One having the temperature-resistance characteristics shown in Figure 3.

Next, the operation of such a device will be explained.

When the commercial power supply 1 is connected to the circuit, a power supply voltage of 220 V is applied to both ends of the lighting tube 50, the lighting tube 6 is operated, and both internal electrodes are short-circuited. by this.

Inductance element 2. A current flows through the positive temperature coefficient thermistor 6 and the electrode filament '4 of the fluorescent pair 4, and the electrode filament of the fluorescent pair 4 is preheated.

Hereinafter, the current at this time will be referred to as preheating current If. This means that the cold resistance of the positive temperature coefficient thermistor 6 at startup is 1oO to 3oO.
This is because the resistance is as low as ooΩ.

The value of this preheating current 11- is determined when the cold resistance value of the PTC thermistor 6 is R(6) and the inductance 'eL(H) of the inductance element 2.

”f=Vs//4Yππy However, vs: is expressed as the voltage of the commercial power supply 1 (a).

By the way, the preheating current is generally 1.6 to 2 of the lamp current.
It is said that approximately twice that amount is optimal in terms of startability and lifespan. In this embodiment, since FLlo is used as the fluorescent pair 4, the lamp current is mA, and the optimum value for the preheating current If is 350 to 600 mA.

The electrode filament of the fluorescent pair 4 is sufficiently preheated by this preheating current, and the fluorescent pair 4 is reliably lit by the kick voltage generated when the electrodes of the lighting tube 6 are opened.

On the other hand, this preheating current causes I(
Since 2H of power is applied, the temperature of the positive temperature coefficient thermistor 6 rises rapidly according to the characteristic curve shown in FIG. 3, and when the temperature reaches 120° C. or higher, the resistance value suddenly increases. In addition, in FIG. 3, R25 on the vertical axis means temperature 2
It represents the resistance value at 6°C.

As a result, after lighting of the fluorescent pair 4, current flows from the commercial power supply 1 to the inductance element 2. It flows to a capacitor 3 and a fluorescent pair 4. The resistance value of the positive temperature coefficient thermistor 6 during operation is set to 1 to allow current to flow through the capacitor 3 when the fluorescent pair 4 is lit.
It is preferable to set it to 00Ω or more.

Furthermore, the operation upon restart will be explained. If the connection of the commercial power supply 1 to the circuit is temporarily cut off from the lighting state of the fluorescent pair 4, and the commercial power supply 1 is reconnected to the circuit within 30 seconds after the cutoff, the inductance element 2. The current flowing through the capacitor 3 and one electrode filament of the fluorescent pair 4, the lighting tube 6 and the other electrode filament of the fluorescent pair 4 is comparable to the lamp current value, but the electrode filament of the fluorescent pair 4 is still Since it is not cooled and the filament temperature of the fluorescent pair 4 is high, the fluorescent pair 4 lights up reliably.

On the other hand, if a time longer than 30 seconds has elapsed, the above situation is not expected, and it becomes difficult to start with a preheating current comparable to the lamp current. Therefore, it is desirable to cool the PTC thermistor 6 approximately 30 seconds after cutting off the current flowing through it. In this case, since the resistance value of the positive temperature coefficient thermistor 6 is low, a preheating current twice the lamp current flows, similar to the operation at startup, and the fluorescent pair 4 can be started easily. .

Note that in order to cool the PTC thermistor in the above-mentioned specific time, in addition to selecting the PTC thermistor itself having such characteristics, a heat sink may be separately attached to the PTC thermistor.

In the above embodiment, FL1 is used as the fluorescent pair.

Although the case where the fluorescent pair is used has been described, the same effect can of course be obtained by using other fluorescent pairs.

In addition, an example in which a lighting tube is used as the lighting element will be described (although a lighting element made of a semiconductor or the like may also be used).

As described in detail, according to the present invention, a series body of an inductance element and a capacitor to be connected to a power source;
Starting by including a fluorescent pair to be connected to the power source via the series body, a lighting element connected to both ends of the fluorescent pair, and a positive temperature coefficient thermistor connected in parallel with the capacitor. When the preheating current of the fluorescent pair can be increased, the electrode filament drop voltage increases, resulting in
Glow discharge between electrode filaments is more likely to occur,
The electrode filament temperature must be high enough to emit electrons, which results in good starting characteristics, less scattering of the electrode emitter due to blinking, and good life characteristics.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a conventional fluorescent lamp lighting device, Fig. 2 is a circuit diagram of a fluorescent lamp lighting device which is an embodiment of the present invention, and Fig. 3 is a positive characteristic used in the fluorescent lamp lighting device. FIG. 3 is a temperature-resistance characteristic diagram of a typical example of a thermistor. 1... Commercial power supply, 2... Inductance element, 3... Capacitor, 4... Fluorescent pair, 6... Lighting tube . 6...Positive characteristic thermistor. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
1XI Figure 3 1 Characteristic Thermistor

Claims (1)

[Claims] a series body of an inductance element and a capacitor to be connected to a power source; a fluorescent pair to be connected to the power source via the series body; a lighting element connected to both ends of the fluorescent pair; A fluorescent lamp lighting device characterized by comprising a capacitor and a positive temperature coefficient thermistor connected in parallel.