JPS61126796A - Discharge lamp lighting apparatus - 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 [Technical Field of the Invention] The present invention relates to a discharge lamp lighting device using a high frequency oscillation circuit.

[Technical background of the invention and its problems] Conventionally, for example, as shown in FIG. 6, AC power l! A rectifier circuit 6 consisting of a full-wave rectifier diode bridge 3, a resistor 4 for power factor improvement and lightning surge absorption, and a smoothing capacitor 5 is connected to the li1 via a filter circuit W12, and the rectifier circuit 6 is connected to a one-block blocking oscillation circuit. A high frequency oscillation circuit 7 consisting of a high frequency oscillation circuit 7 is connected, a fluorescent lamp 9 is connected to the output terminal of the oscillation circuit 7 via a current limiting choke 8, and a diode, a 5SS (silicon symmetrical switch), etc. are connected to the fluorescent lamp 9. It is known that a current interrupting circuit 10 consisting of two-way constant voltage switching elements is connected in parallel as a starting circuit.

However, in this device, the voltage applied to the discharge lamp 9 is determined by the output voltage of the oscillation circuit 7, so in order to provide sufficient pulse voltage for starting at a low temperature of 0°C to 5°C, the oscillation circuit 7 must be The output voltage of the oscillation circuit must be set high, which means that the transformer used in the oscillation circuit and the coils in the circuit must be larger, or the transistor used for switching in the oscillation circuit must have a high withstand voltage. There were drawbacks.

In order to eliminate this drawback, for example, as shown in FIG. It is conceivable to connect the current interrupt circuits 10 in parallel to form the starting circuit 12.

In this way, the voltage generated in the auxiliary winding can be transferred to the oscillation circuit 7.
A relatively high voltage starting pulse is superimposed on the output voltage of the fluorescent lamp 9, so that starting and lighting can be performed relatively smoothly at low temperatures. However, the direction of the iode in this 'il flow interrupter circuit 10 is as shown in FIG. , the output waveform a of the high frequency oscillation circuit 7 is compared to b
A starting pulse as shown in Figure 1 is now generated, and the peak voltage of this starting pulse is approximately 580cm, which is not that high, and it is difficult to start due to manufacturing variations, etc., and it is difficult to turn off the lamp, such as fluorescent lamps or amalgam-containing fluorescent lamps. There is a problem in that it is not possible to start and light a fluorescent lamp in a short time because the mercury vapor pressure immediately after the lamp becomes extremely low and it becomes difficult to restart the lamp.

[Purpose of the Invention] This invention was made in order to solve such problems, and it is possible to obtain a sufficiently high starting pulse voltage, and it is possible to obtain a starting pulse voltage of sufficient height, and it is possible to start the discharge lamp at low temperatures, even if there are manufacturing variations. To provide a discharge lamp lighting device capable of quickly starting and lighting even a discharge lamp that is difficult to restart or a discharge lamp that is difficult to restart immediately after extinguishing.

[Summary of the Invention] This invention connects a high frequency oscillation circuit to an AC power supply via a rectifier circuit, connects a discharge lamp to the output end of the oscillation circuit via a current limiting choke, and connects a starting circuit to the discharge lamp. In a discharge lamp lighting device connected in parallel, a bidirectional constant voltage switching element and a diode are connected in series to the discharge lamp as a starting circuit via an auxiliary winding for starting which is magnetically coupled to a current limiting choke. A current cutoff circuit consisting of two circuits is connected in parallel, and the diode direction is set so that the anode of the diode is on the positive side of the output end of the rectifier circuit, and the cathode is on the current-limiting choke side. , thereby increasing the voltage of the starting pulse.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a rectifier circuit 25 is connected to an AC power source 21 via a filter circuit 24 consisting of a capacitor 22 and an inductance coil 23. The rectifier circuit 25
is a full-wave rectifier diode bridge 26, and a smoothing capacitor 2 connected to the output terminal of this diode bridge 26 via a resistor 27 for power factor improvement and lightning surge absorption.
8, and the input terminal of the diode bridge 26 is connected to the filter circuit 24. A high frequency oscillation circuit 29 of, for example, a single-stone type is connected to the output terminal of the rectifier circuit 25, that is, to both ends of the smoothing capacitor 28. This high frequency oscillation circuit 29 has an output transformer 30. The primary winding 30 of this output transformer 30
A capacitor 31 forming a resonant circuit with p, an NPN transistor 32, a diode 33 that drives this transistor 32, a base winding 130b of the output transformer 30, a series circuit of a resistor 34 and a diode 35, and a series circuit of a resistor 34 and a diode 35. Starting capacitor 36 connected in parallel to the series circuit
, starting resistor 37, inductance coil 38 and resistor 39
This is a well-known drive circuit composed of a drive circuit 40 consisting of a parallel circuit with the secondary winding 3 of the output transformer 30, etc.
0s is the output terminal.

A current limiting choke 41 is connected to the output terminal of the high frequency oscillation circuit 29.
One ends of filament electrodes 42a and 42b of a discharge lamp, for example, a fluorescent lamp 42, are connected through the terminal. Between the other ends of the filament electrodes 42a and 42b of the fluorescent lamp 42, a starting auxiliary winding 43 magnetically coupled to the current limiting choke 41 is connected to a diode 44, 45 as a bidirectional constant voltage switching element. A current interrupting circuit 47 consisting of a series circuit with an SSS element 46 is connected to constitute a starting circuit 48. Each of the diodes 44, 45 has its direction
The anode is connected to the positive side of the output terminal of the rectifier circuit 25,
That is, one filament electrode 42 of the fluorescent lamp 42
a side, and its cathode is connected to the current limiting coil 41 side, that is, the other filament electrode 42b side of the fluorescent lamp 42.

In the device of the present invention having such a configuration, when the applied voltage reaches the breakover voltage of the SSS element 46 in a state where one filament electrode ff142a of the fluorescent lamp 42 is positive with respect to the other filament electrode 42b, The SSS element 46 becomes conductive and a preheating current flows through each filament electrode 42a, 42b. When the SSS element 46 becomes cut-off due to a decrease in the applied voltage, a large starting pulse voltage is generated by the action of the current limiting choke 41 and the auxiliary winding 43, and between the two filament electrodes 42a and 421) of the fluorescent lamp 42. is applied to

At this time, as shown in FIG. 2, the output waveform a of the oscillation circuit 29 is
In contrast, a starting pulse voltage as shown in b is generated, and the peak voltage of this starting pulse is about 700 V, which is about 100 mm higher than that shown in FIG. 7 described above. Therefore, even if the fluorescent lamp 42 is placed at a low temperature of 0° C. to 5° C. or is difficult to light due to manufacturing variations, it can be started and turned on quickly in a relatively short time.

According to experiments, when the temperature was 25℃ and the input power was 100V, dozens of fluorescent lamps that were difficult to turn on using the one shown in Figure 7, which took more than 3 seconds to start, were turned on with this device. I was able to start it and turn it on within seconds.

Next, another embodiment of the invention will be described with reference to the drawings.

Note that the same parts as in the above embodiment are given the same reference numerals, and detailed explanations will be omitted.

The one shown in FIG. 3 has a capacitor 49 in the current cutoff circuit 47.
are connected in parallel. By doing so, an LC series resonant circuit can be formed with the auxiliary winding 43 and the capacitor 49, and the action of this resonant circuit makes it possible to generate a starting pulse with a higher pitch. can. Therefore, in this embodiment as well, the same effects as in the previous embodiment can be obtained.

In addition, the one shown in FIG. 4 has a capacitor 5 in the auxiliary winding 43.
0 in parallel, its auxiliary winding 43 and capacitor 5o
An LCC parallel common circuit is formed with this circuit, and in this circuit as well, a sufficiently high starting pulse voltage can be generated, and the same effects as in the previous embodiment can be obtained. Note that 51 indicated by a dotted line in the figure is a stray capacitance.

Roughly speaking, what is shown in Fig. 5 is the auxiliary winding 43 and the electric wire 8! An LC parallel resonant circuit consisting of an inductance coil 52 and a capacitor 53 is connected between the E cutoff circuit 47, and this circuit can also generate a sufficiently high starting pulse voltage, and has the same effect as the previous embodiment. is obtained.

In the above embodiments, a single-stone type high-frequency oscillation circuit was used, but the present invention is not necessarily limited to this, and a push-pull type consisting of two stones may be used.

[Effects of the Invention] As detailed above, according to the present invention, a sufficiently high starting pulse voltage can be obtained, and it can be used not only for discharge lamps at low temperatures, but also for discharge lamps that are difficult to start due to manufacturing variations and for turning off lights. To provide a discharge lamp lighting device capable of quickly starting and lighting even a discharge lamp that is difficult to restart immediately afterward.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing an embodiment of the present invention, Fig. 2 is a diagram showing a starting pulse waveform in the same embodiment, Figs.
FIG. 5 shows circuit-1 No. 6 showing another embodiment of the present invention.
7 is a circuit diagram showing a conventional example, FIG. 7 is a diagram showing an improved example of the conventional example, and FIG. 8 is a diagram showing a starting pulse waveform in FIG. 7. 21... AC power supply, 25... Rectifier circuit, 29...
High frequency oscillation circuit, 41... Current limiting choke, 42...
Fluorescent lamp, 43... Auxiliary winding, 44.45... Diode, 46... SSS element (bidirectional constant voltage switch), 48... Starting circuit. Applicant's agent Patent attorney Takehiko Suzue Figure 1 0b 12

Claims (1)

[Claims] Connect a high frequency oscillation circuit to an AC power source via a rectifier circuit,
In a discharge lamp lighting device in which a discharge lamp is connected to the output end of the oscillation circuit via a current limiting choke, and a starting circuit is connected to the discharge lamp in parallel, the starting circuit connects the discharge lamp to the limiting choke. A current interrupting circuit consisting of a series circuit of a bidirectional constant voltage switching element and a diode is connected in parallel through an auxiliary winding for starting that is magnetically coupled to a current choke, and the direction of the diode is A discharge lamp lighting device characterized in that the anode of the diode is set to be on the positive side of the output end of the rectifier circuit, and the cathode is set to be on the side of the current limiting choke.