JPS61190899A - Discharge lamp lighting device - 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 Industrial Application] The present invention relates to a discharge lamp lighting device capable of lighting a discharge lamp equipped with a preheating electrode like a fluorescent lamp. This invention relates to an improvement in a preheating circuit for a preheating electrode of a discharge lamp.

[Prior art and its problems]

FIG. 4 is an example of a conventional discharge lamp lighting device that can dimly light a discharge lamp equipped with a preheating electrode such as a fluorescent lamp. In this device, a transformer 3 is connected to an AC power supply 1 via a phase control type semiconductor switching element 2 such as a triac, and a discharge lamp 5't- is provided with preheating electrodes 4a, 4b'i on the output side of the transformer 3. It is connected. In this device, in addition to the power supply voltage whose phase is controlled by the transformer 3, in order to keep the voltage of the preheating electrodes 4a, 4bt and the heating windings 6a, 6b constant even when dimming the 8-discharge lamp 5, It is necessary to provide an uncontrolled supply voltage. Therefore, as shown in the figure, a part of the input winding of the transformer 3 must be directly connected to the AC power supply 1 using another wire 7, which not only requires time and effort for the assembly, connection, and wiring of the transformer, but also It also has the disadvantage of high cost.

[Purpose of the invention]

An object of the present invention is to provide a discharge lamp lighting device that eliminates the above-mentioned drawbacks and is capable of dimming a discharge lamp and heating a preheating electrode using only a phase-controlled power supply voltage. The purpose is to

[Structure and operation of the invention]

FIG. 1 shows an embodiment of a discharge lamp lighting device according to the present invention. This device has a transformer 3 connected to an AC power source 1 via a phase-controlled A type semiconductor switching element 2, and a discharge lamp 5 equipped with a pre-IIP and M poles 4m+4b1 connected to the output side of the transformer 3. In this case, a high frequency generator #8 operated by the capacitor T and the charge charged in the capacitor 7 is connected to the input side of the transformer 3 through a rectifier circuit 6''lr, and the output transformer 9 of the high frequency generator t8 ie
The discharge lamp 5 is configured to heat the preheating electrodes 4m and 4bi. Note that the high frequency generator 8 includes:
A generally known two-stone transistor inverter may be used.

Next, the operation of the marking meeting will be explained. First, AC'B
The Y source 1 is turned on and the conduction phase angle of the semiconductor switching element 2 is adjusted to an appropriate range. As a result, a phase-controlled voltage as shown in FIG. will be applied.

At the same time, a capacitor 7 (suitably an electrolytic capacitor) is charged via the rectifier circuit 6, and the two high-frequency generators 18 start operating based on the electric charge. This results in
A voltage as shown in FIG. 2(b) is generated on the output side of the output transformer 9 of the high frequency generator 8, and the preheating electrodes 4m and 4b of the discharge lamp 5 are heated. lights up.

Therefore, in the above configuration, the capacitance tt of the capacitor 7
- If an appropriate value is selected in advance, the preheating electrodes 4m and 4b will be continuously heated by the photoelectric charge of the capacitor T in the phase where the voltage between terminals A and B becomes zero, so that the discharge lamp The dimming state of No. 5 is stable, and there is no adverse effect on the discharge lamp's operating characteristics, lifespan, etc. In addition, Fig. 3(a) and Fig. 3(a)
b) shows the waveforms of the voltage between terminals A and B and the output voltage of the output transformer 9 at the time of non-dimming.

〔Effect of the invention〕

As explained above, according to the present invention, the heating effect of the preheating electrode of the discharge lamp does not deteriorate significantly even when the power supply voltage is phase-controlled, so that the power supply voltage is not phase-controlled using a separate line as in the conventional device. There is no need to supply the transformer, which simplifies the assembly, wiring, and wiring of the transformer, and reduces costs. In addition, recently, dimmers that use ordinary ballasts to save power (so-called power savers) have been put into practical use. Since sufficient heating is carried out, the discharge lamp is less likely to go out, making it possible to increase the amount of power saved and extend the life of the lamp. Furthermore, in the present invention, since the smoothing circuit is provided only in the preheating circuit of the discharge lamp,
Unlike an all-electronic dimming type ballast, it does not require a large capacitor, and therefore there is no risk of increasing the size of the device or reducing circuit efficiency.

[Brief explanation of drawings]

Figure 1 is a circuit diagram of a parabolic lamp lighting device according to the present invention, Figures 2 (a) and (b) are input voltage waveforms and output voltage waveforms of a high frequency generator during dimming in the lighting device, and Figure (a
), (b) shows the input voltage waveform and the output voltage waveform of the high-frequency generator during non-blinking, and FIG. 4 shows the circuit opening of a conventional similar discharge lamp lighting device. In Figure 1, 1... AC power supply, 2... semiconductor switching element,
3...Transformer, 4m, 4b...Preheating electrode, 5...
・Discharge lamp, 6ae6b...preheating winding, T...primary side winding.

Claims (1)

[Claims] In a discharge lamp lighting device in which a transformer is connected to an AC power source via a phase-controlled semiconductor switching element, and a discharge lamp equipped with a preheating electrode is connected to the output side of the transformer, a rectifier circuit is connected to the input side of the transformer. A discharge lamp lighting device characterized in that a capacitor is connected to a high frequency generator operated by the charge of the capacitor, and an output transformer of the high frequency generator heats a preheating electrode of the discharge lamp.