JPS59196596A - 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 lighting device for a discharge lamp, and more particularly to a lighting device for a discharge lamp with improved startability and efficiency.

FIG. 1 shows a circuit diagram of an inverter-type discharge lamp lighting device that has a large-capacity capacitor in the rectifier section of the power supply to achieve complete smoothing. This inverter-type discharge lamp lighting device uses a commercial AC power supply 1 after full-wave rectification, and a smoothing capacitor 4
The power is smoothed by the transistor inverter circuit 5, and is oscillated at a frequency of approximately 25 to 40KH2, converted to high-frequency power, and connected to the secondary winding 6B of the oscillation transformer 6 and the electrode heating windings 6b, 6b''. This device starts and lights up a fluorescent discharge lamp 8.In such a device, since the capacity of the smoothing capacitor 4 is large, the current flowing into the capacitor 4 is also large, resulting in a low input power factor of the circuit, which further reduces starting performance. It has the disadvantage that it is evil (see the notes to the table below).

FIG. 3 is a circuit diagram of a pulsating current lighting type inverter-type discharge lamp device excluding the smoothing capacitor 4 in the circuit shown in FIG. Since there is a zero section in the lamp current waveform (section tl in FIG. 4C) in which no current flows, when trying to make the lamp load output the same output, the following happens.

As a circuit that can eliminate each of the above-mentioned drawbacks of both of the above circuits, the "valley" part of the pulsating flow is smoothed in the power rectifier by filling it to about 1/2 of the height of the pulsating current peak value. There is a device as shown in the circuit diagram of FIG. 5, which is provided with an intermediate smoothing circuit. That is, in this device, the smoothing capacitor 4a in FIG. 1 is replaced by two capacitors 11 and 12 of the same capacity.
, and three diodes 10, 13 and 14 are replaced by a series charging/parallel discharging type smoothing circuit. When this series charge parallel discharge circuit is charged with the output voltage of the diode bridge 3, two capacitors 11 and 12 of the same capacity are charged in series through the diode 10, and the capacitor voltage is Approximately 1 of the peak value of the output voltage of
/2, and the output voltage of the diode bridge 3 decreases from the peak value and approaches the trough of the pulsating current of full-wave rectification, and when it becomes approximately 1/2 of the peak value, those capacitors 11
．． The charged charges of 12 are discharged through diodes 13 and 14 to supply power to the transistor inverter circuit 5. In other words, the output voltage of the diode bridge 3 is supplied to the transistor inverter circuit 5 with a waveform (FIG. 6) that partially fills the trough of the pulsating current of full-wave rectification. Therefore, this inverter type discharge lighting device has a lamp current waveform as shown in FIG. 6C, and becomes a high power factor lighting circuit.

The circuits shown in Figures 1, 3, and 5 are named the completely smooth inverter, pulsating current inverter, and intermediate smooth inverter, respectively, and the main features of devices using these circuits are described below. The comparison is as shown in the table below.

In this table, 1. Flickering at low temperatures in the last column means that when a discharge lamp is lit at low temperatures (approximately 0°C to approximately -10°C), the discharge is stable for several minutes after the discharge starts. This phenomenon is particularly noticeable in the case of power-saving discharge lamps that contain krypton gas, argon gas, etc., as light bulbs appear and move rapidly, causing flickering in the light emission. As can be seen from Table 1, this phenomenon occurs even when an intermediate smooth type inverter is used, but it does not occur only when an inefficient pulsating flow type inverter is used.

Based on this knowledge, we have already combined the smoothing circuit of the intermediate smoothing method with a circuit that utilizes the characteristics of a thermistor to keep the smoothing circuit in a state close to cutoff at the beginning of lighting, and as the temperature of the device rises, the smoothing circuit becomes smoother. A discharge lamp lighting device has been proposed in which the circuit is configured to gradually enter operation. However, when such a device is used in a cold environment with good ventilation (5), the temperature of the thermistor does not rise sufficiently even after a sufficient period of time has passed and the discharge has stabilized, causing the device to malfunction. However, it has the disadvantage that it continues to operate as a pulsating flow type inverter forever.

An object of the present invention is to provide a lighting device for a discharge lamp that eliminates the drawbacks of all of the above devices, including a device that uses a thermistor to shift from a pulsating current inverter to an intermediate smooth inverter. It is about providing.

In order to achieve the above object, the lighting device for a discharge lamp according to the present invention is a device that connects a rectifier circuit to an AC power source and lights a fluorescent lamp using high-frequency power obtained by converting the DC output voltage of the rectifier circuit with an inverter. A circuit in which two capacitors of the same capacity are connected in series with a thermistor in between is connected between the output terminals of the rectifier circuit so that the forward current direction of the thyristor matches the output polarity of the rectifier circuit. At the same time, a diode whose forward direction is in the direction from the connection point between the positive electrode of the Sairisk and one of the two capacitors to the positive electrode side of the output terminal of the rectifier circuit, and From the negative electrode side, connect a diode whose forward direction is toward the connection point between the negative electrode of the Cyrisk and the other capacitor of the two capacitors, provide a timer circuit for starting the Cyrisk, and connect the power supply. After a predetermined time has elapsed after the input, a gate signal is applied from the timer circuit to the gate of the thyrisk, so that the thyrisk becomes conductive.

An embodiment of the present invention will be described below based on FIG. 7. In this figure, parts common to the circuit parts shown in FIGS. 1, 3, and 5 are given the same reference numerals, and explanations of these parts will be omitted. In the circuit shown in FIG. 7 as well, the smoothing circuit section 4 employs an intermediate smoothing type smoothing circuit of the series charging/parallel discharging method, similar to the circuit shown in FIG. 10 is here replaced by a thyristor 10a. A diode 13 is connected from the connection point between the positive side of the thyristor 10a and the capacitor 12 to the positive side line of the rectifier circuit 3 so that the forward direction coincides with that direction. 10a negative electrode side and capacitor 11
A diode 14 is connected toward the connection point so that the forward direction coincides with that direction. The winding 6d provided in the oscillation transformer 6 is a winding for the driving power source of the timer circuit 7.

When the power switch 2 is turned on in the circuit shown in FIG. 7, a pulsating current that is full-wave rectified by the diode bridge 3 is generated on the output side of the diode bridge. Immediately after the power switch 2 is turned on, the thyristor 10a in the series charging/parallel discharging circuit 4, which constitutes a part of the present invention, is out of conduction, so the lamp is exactly the same as the pulsating current lighting type inverter discharge lamp device shown in FIG. The secondary line g! of the oscillation transformer 6 starts. 6B, the fluorescent discharge lamp 8 connected to the electrode heating wires 6b, 6b' starts and lights up quickly. At this time, the voltage across the fluorescent discharge lamp 8 has a waveform as shown in FIG. 4B, and the lamp current has a waveform as shown in FIG. 4C. As described above, this lamp current waveform is tl, and when the power-saving lamp is started at a low temperature, no flickering of the characteristic moving stripes is observed at all. Several minutes pass like this. When the time required for the discharge state of the fluorescent discharge lamp 8 to become completely stable (about 5 to 6 minutes) has elapsed, a signal is added between the gate and cathode of the thyristor 10a from the timer circuit 7, and the thyristor tOa becomes conductive. It goes through. When the thyristor 10a becomes conductive, the circuit partially becomes the same as the circuit shown in FIG. 5, and as described above, operates in the same manner as the intermediate smoothing type inverter type discharge lamp lighting device. Note that in FIG. 7, a capacitor 15 is inserted for noise prevention.

As is clear from the above description, according to the present invention, the fluorescent discharge lamp 8 can be started very easily, and at the same time, there may be unpleasant flickering of moving stripes during the early stage of discharge, especially when the power-saving lamp is started and lit at low temperatures. Thus, a discharge lamp lighting device can be obtained which outperforms conventional circuits in all respects, such as having a high overall efficiency after the discharge stabilizes and being able to maintain a high circuit power factor.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a conventional discharge lamp lighting device having a complete smoothing capacitor in the rectifier, and FIGS. 2 and 2a are diagrams for explaining the operation of the device shown in FIG. 1. be. FIG. 3 is a circuit diagram of a discharge lamp lighting device according to the prior art that does not have a smoothing means in the rectifier, FIG. 4, and FIG. 4a.
, 4S and 4C are explanatory views of the operation of the apparatus shown in FIG. 3. Fig. 5 is a circuit configuration diagram of a discharge lamp lighting device which employs a conventional series charging/parallel discharging type intermediate smoothing circuit in the rectifying section; Fig. 6; Fig. 6a; Figure C is an explanatory diagram of the operation of the apparatus shown in Figure 5. FIG. 7 is a circuit configuration diagram of an embodiment of the present invention. 1 - AC power supply 2 - Power supply switch 3 - Full wave rectifier circuit 4 - Smoothing circuit 5 - Electronic circuit part of inverter 6 - Oscillation transformer 7 - Timer circuit 8 - Discharge lamp 10, I 3. 14-Diode 1Qa-Sirisk 11, 12. 15- Capacitor patent applicant: Kyoshin Electric Manufacturing Co., Ltd.
Attorney Patent Attorney Nishi 1) New Figure 6, Figure 6, Figure 6, Figure 6, Figure 6, Figure 6, Figure 6, C. Procedural Official Book (tq'i) 1981 Patent Application No. 71908 2, Title of Invention Lighting of a discharge lamp Device 3, Name of person making the amendment Kyoshin Electric Manufacturing Co., Ltd. Representative: Yukio Watanabe 4, Agent address: 15-13-5, Usagano-cho, Kita-ku, Osaka-shi, Weight of amendment order: Voluntary amendment 6, Subject of amendment: Specification 7, Amendment Contents of the amendment as shown in the attached sheet (1, 1 Claims are amended as shown in the attached sheet. (2) Description box 2, lines 12 to 133 [transistor (3) The statement on page 6, line 5 of the specification: “(approximately 0゛C to approximately -1
0°C) J is corrected to 1 (approximately 0°C to approximately -10°C). (4) The statement "Table 1" on the 10th line is corrected to read "Table." (5) In the table on page 6 of the specification, 2nd row, 2nd column, "Bottom power factor" is corrected to "Low power factor." (6) On page 7, line 15 of the specification box, replace the word ``thermistor'' with ``thyrisk''. (7) The statement "positive electrode" on the 18th line is corrected to "cathode". (8) In the second line of page 8 of the specification box, the words "negative electrode" are corrected to "anode." (9) The description on the 19th line is “positive electrode side” and “cathode side”.
and correct it. (1 (11) The statement "Negative electrode side" on page 9, line 3 of specification box is corrected to "anode side". (I+) The statement "Secondary line theory" on line 15 of the same specification is corrected as "
Corrected as "secondary line ring". O From line 15 to line 166 of the same, the phrase "electrode heating wire" is corrected to "electrode heating wire." 0 In the third line of page 10 of the specification box, the statement ``Butashi Naga et al.'' is amended to read ``However.'' 64) The statement from line 7 to line 8 “(about 5 to 6 minutes)”
Correct the statement to "(approximately 5-6 to 20 minutes)". Claims: A device for lighting a fluorescent lamp using high-frequency power obtained by connecting a rectifying circuit to an AC power source and converting the DC output voltage of the rectifying circuit using an inverter, wherein: between the output terminals of the rectifying circuit;
A circuit in which two identical capacitance capacitors are connected in series with a sirisk in the middle is connected so that the forward current direction of one sirisk matches the output polarity of the rectifier circuit,
From the connection point between the electrode of the thyrisk and one of the two capacitors, a diode whose forward direction is in the direction toward the positive electrode side of the output terminal of the rectifier circuit, and from the negative electrode side of the output terminal of the rectifier circuit. , a diode whose forward direction is directed toward the connection point between the positive terminal of the Cyrisk and the other capacitor of the capacitors 2 (11i!) is connected, a timer circuit is provided to start the Cyrisk, and the power source is 1. A lighting device for a discharge lamp, characterized in that, after a predetermined time has elapsed after turning on, a gate signal is applied from the timer circuit to the gate of the cylisk so that the cylisk becomes conductive.

Claims (1)

[Claims] In a device that connects a rectifier circuit to an AC power source and lights a fluorescent lamp with high-frequency power obtained by converting the DC output voltage of the rectifier circuit with an inverter, there is a device between the output terminals of the rectifier circuit.
A circuit in which two identical capacitance capacitors are connected in series through a cyrisk in the middle is connected so that the forward current direction of the thyrisk matches the output polarity of the rectifier circuit,
From the connection point between the positive electrode of the Sairisk and one of the two capacitors, a diode whose forward direction is in the direction toward the positive electrode side of the output terminal of the rectifier circuit, and from the negative electrode side of the output terminal of the rectifier circuit. , a timer circuit is provided for activating the Sairisk by connecting a diode whose forward direction is toward the connection point between the negative electrode of the Cyrisk and the other capacitor of the two capacitors;
1. A lighting device for a discharge lamp, characterized in that, after a predetermined time has elapsed after power is turned on, a gate signal is applied from the timer circuit to the gate of the cyrisk, so that the cyrisk becomes conductive.