JPS58218797A - 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] [Technical field of invention] The present invention relates to a discharge lamp lighting device.

[Technical background of the invention and its problems]

In a discharge lamp lighting device that uses a ballast, it is desirable to reduce the loss of the ballast and make it smaller and lighter. To achieve this, it is necessary to reduce the circuit current and increase the tube voltage when lighting the discharge lamp. It is known that the number of turns and diameter of the ballast can be reduced by using a high-load type. 'However, if the tube voltage of the discharge lamp is increased, there is a risk that the discharge lamp may go out when restarted every half cycle. For this reason, in the conventional discharge lamp lighting device, the same high-voltage pulse as at the time of starting is applied to the discharge lamp every half cycle to maintain the re-ignition.

However, although it is necessary to apply a high-voltage pulse when starting a discharge lamp, maintaining the re-ignition after lighting does not require as much high-voltage pulse; in fact, the high-voltage pulse may cause the discharge lamp to fail prematurely. There was that.

[Purpose of the invention]

This invention was made in order to solve such problems, and it is possible to maintain the re-ignition of the discharge lamp after lighting it to a sufficiently low level compared to when it is started. To provide a discharge lamp lighting device which can prevent a discharge lamp from becoming defective at an early stage by applying a pulse and is free from the risk of other circuits being adversely affected by the high voltage pulse at startup. The purpose is to

[Summary of the invention]

This invention applies a high-voltage pulse generated by a high-voltage/dulse generating circuit between both electrodes of the discharge lamp when starting a discharge lamp, and also applies the high-voltage pulse generated by a high-voltage/dulse filter circuit to
This prevents the pulse from being applied to the nonlinear dielectric element, and after the discharge lamp is turned on, the operation of the high-voltage pulse generation circuit is stopped due to a drop in the tube voltage of the discharge lamp. A low-voltage pulse is applied every half cycle of the power supply voltage to maintain restriking.

[Embodiment of the Invention] FIG. 1 is a circuit diagram showing an embodiment of the present invention, in which a nonlinear dielectric element 3 is connected to an AC power source 1 via a ballast 2. In FIG. A high-voltage pulse generating circuit 5 and a discharge lamp 6 are connected in parallel to the nonlinear dielectric element 3 via a coil 4 forming two Δsisfil circuits. Here, "parallel" means that a resistive element or the like may be connected in series to a nonlinear dielectric element, and a high voltage/gas generating circuit 6 and a discharge lamp 6 may be connected in parallel to this series circuit via a coil 4. means. The high voltage/high voltage pulse generating circuit 5 includes a series circuit of a resistor 7 and a capacitor 8, and a series voltage dividing circuit of resistors 9 and 10 is connected in parallel to the capacitor 8, and a bidirectional three-terminal thyristor I and NO are connected in parallel. A series circuit with the primary winding 12P of the transformer 12 is connected in parallel. A capacitor 13 is connected in parallel to the resistor 10, and one end of the capacitor 13 is connected to a bidirectional two-terminal thyristor (hereinafter referred to as a trigger element).
14 to the r-) of the thyristor 11, and the other end is connected to the primary '11A=line 12P of the pulse transformer 12.
It is connected to the terminal of the thyristor 11 via. Further, the high voltage nozzle generating circuit 5 includes a resistor 7 and a capacitor 8.
A series circuit consisting of the capacitor 15 and the secondary winding 12B of the Noyals transformer 120 is connected in parallel to the series circuit.

In the embodiment of the present invention having such a configuration, when the power supply 1 is turned on, the power supply voltage becomes high voltage J? Lux generation circuit 5 and discharge lamp 6
0 is applied between both ends. The power supply voltage now rises at side 1o. A capacitor 8 is charged via a resistor 7, a voltage across the capacitor 8 is divided by resistors 9 and 10, and a capacitor 13 is charged by the divided voltage. Then, at time t1, the charging voltage of the capacitor 13 becomes t1)! When the breakover voltage of element x4 is reached, its trigger element becomes conductive, thereby causing thyristor 11 to conduct. Therefore, the voltage across the thyristor 11 becomes zero at time 11, as shown in (,) in FIG. As a result, a main current having a somewhat lasing shape as shown in FIG. 2(b) flows through the Noculus transformer 12 to the primary winding 12P. As a result, a high voltage pulse is generated in the secondary winding 12B of the pulse transformer 120, and the high voltage pulse is generated.

is applied across the discharge lamp 6 via the capacitor 15, superimposed on the power supply voltage as shown in FIG. 2(C). The high voltage pulse generated at this time is a steep pulse with a narrow width, so if the inductance of the coil 4 is set to an appropriate value, the pulse will not pass through the coil 4 and will be applied to the nonlinear dielectric element 3. There is no danger. This high voltage/glucose generating circuit 5 continues to operate at time t,' e j4 *
t, . . . are connected to the thyristor, generating several high-voltage pulses in one cycle. The power supply voltage is also applied to the nonlinear dielectric element. By the way, nonlinear dielectric element 3
is the voltage ν that provides a coercive electric field, as shown in (&) in Figure 3, so that when the applied voltage τ is changed, the characteristic of the amount of charge with respect to the voltage V exhibits hysteresis characteristics.
= V, the reversal current becomes almost maximum. This reversal current characteristic occurs every half cycle of the power supply voltage. When this current 1 flows through the ballast 2 with an inductance of L, at τ=vc, v-L-! ! L standing, P
A pulse voltage below dt 'dv d2υ is generated. This pulse voltage is lower in intensity than the high-voltage noise generated from the high-voltage pulse generating circuit 5 and has a sufficiently wide width, and is applied to the discharge lamp 6 after passing through the coil 4.

In this way, when starting the discharge lamp 6, the high-voltage i44 pulse generator circuit 5
When both the high voltage and pulse voltage vP and the voltage caused by the operation of the nonlinear dielectric element 3 are applied, the lighting operation is caused by the repeated application of the high voltage and pulse voltage. Start control is performed. When the discharge lamp 6 starts lighting, the tube voltage vL of the discharge lamp 6 decreases. Due to this decrease in the tube voltage vL, the charge level of the cone capacitor 8 in the high voltage/'P pulse generating circuit 6 decreases, and the voltage across the resistor 10 decreases. Therefore, tri-element 1
If the breakover voltage of No. 4 is set higher than the voltage generated across the resistor 100 after the lamp is turned on, the charge level of the capacitor 13 will never reach the breakover voltage of the tri-f element 14, so the cyrisk 1 no. Remains non-conductive. In other words, after the discharge lamp 6 is turned on, the operation of the high-voltage/lumen generating circuit 5 is stopped. After the discharge lamp 6 is turned on, only the pulse voltage V generated every half cycle of the power supply voltage by the operation of the nonlinear dielectric element 3 is applied to the discharge lamp 6.

Therefore, the tube voltage vL of the discharge lamp 6 after lighting is the fourth
As shown in FIG. 3, the discharge lamp 6 is maintained to be re-ignited every half cycle. In this way, even if a high-load discharge lamp is used as the discharge lamp-6, its red light will last for a minute. Of course, in this case, the voltage vc that provides the coercive electric field of the nonlinear dielectric element 3 must satisfy vc<vL.

In this way, when the discharge lamp 6 is started, it can be started and lit by applying high voltage and 4 pulses from the high voltage/4 pulse generation circuit 5, and after the discharge lamp is lit, it can be started by the operation of the nonlinear dielectric element 3. The relatively low-level guru voltage v that occurs
It is possible to maintain restriking by applying P. Since the high voltage pulse from the high voltage pulse generation circuit 5 is absorbed by the coil 4, it is applied only to the discharge lamp 6 and there is no possibility that it will be applied to the nonlinear dielectric element 3. Therefore, the discharge lamp 6 has iJ? There is no risk of early failure due to the application of the l and

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.

Figures 5 to 7 show other embodiments of the high voltage/4 pulse generation circuit, and Figure 5 uses a single-turn coil 16 as an i4 pulse transformer, and a thyristor is connected to the coil 16 in the evening and in the notch. 11 terminals are connected. In addition, Fig. 6 uses a single-turn coil 16 as a pulse transformer, and a bidirectional 3
Unidirectional 3-terminal thyristor 17 instead of terminal thyristor
At the same time, the thyristor 17 is connected in series to the single-turn coil 16, and a full-wave rectifier diode bridge circuit 18 is connected in place of the capacitor 8. Resistance 9 and 1
0 series voltage divider circuit and a single-turn conil 16
tag t1 of part of its coil 16 and thyristor J7
A series circuit is connected. Furthermore, in FIG. 7, a unidirectional three-terminal thyristor 17 is used in place of the bidirectional three-terminal thyristor, and the AC input terminals of the full-wave rectifier diode circuit 18 are connected via a resistor 7. A capacitor 8 is connected between the rectified wave output terminals of the bridge circuit 18. Series voltage divider circuit of resistors 9 and 10 and thyristor 1
7 and the primary winding JjP of the arm transformer 12 are connected in series.

Even if the high-voltage pulse generation circuit is modified in this way, the same effects as in the embodiment described above can be obtained.

In FIG. 8, the coil 4 is also used as the secondary winding 128 of the nozzle transformer 12 in the high-voltage nozzle generating circuit 5, and in this case, the coil 4 and the capacitor 15
can be omitted and the circuit can be simplified. In addition,
In this case as well, the same effects as in the above embodiment can be obtained.

In each of the above embodiments, the pulse filter circuit is formed of a coil, but the pulse filter circuit is not limited to this, and may be formed of a capacitor. Fluorescent lamps can also be applied to discharge lamps by providing a preheating circuit.

〔Effect of the invention〕

As described above, according to the present invention, a high-voltage pulse is applied at the time of starting the discharge lamp, and also after the discharge lamp has been turned on, in order to maintain the re-ignition of the discharge lamp by applying the pulse voltage. It is possible to apply high-voltage pulses and prevent the high-voltage pulses from having an adverse effect on other circuits other than the discharge lamp, and to keep the level of the pulse voltage applied after the discharge lamp is lit to a low level, thereby preventing the discharge lamp from becoming defective at an early stage. Discharge lamps that can be prevented

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention. FIG. 1 is a circuit diagram, FIG. 2 is a waveform diagram of each part obtained by the operation of the high-voltage pulse generation circuit, and FIG. 3 is a nonlinear Iltl diagram. FIG. 4 is a waveform diagram showing the operating characteristics of the element; FIG. 4 is a waveform diagram showing changes in the tube voltage of the discharge lamp due to the operation of the nonlinear dielectric element; FIGS. 5 to 8 are diagrams showing other embodiments of the present invention. 5 to 7 are partial circuit diagrams showing only the high voltage pulse generation circuit,
FIG. 8 is an overall circuit diagram. DESCRIPTION OF SYMBOLS 1...AC power supply, 2...Ballast, 3...Nonlinear dielectric element, 4...Coil, 5...High voltage flux generation circuit, 6...Discharge lamp. ,”- Applicant's agent Patent attorney Takehiko Suzue Figure 2 Figure 3 (a) (b) Figure 4
Figure rA5 Figure 6 Figure 81!7 Figure mB Figure

Claims (1)

[Claims] An AC power supply, a nonlinear dielectric element connected to this power supply via a ballast and operated every half cycle of the power supply voltage, and a row of discharge lamps connected in parallel to this nonlinear dielectric element. A high voltage pulse generation circuit that applies a high voltage/4 pulse between both ends, and a pulse filter circuit inserted between this high voltage pulse generation circuit and the above-mentioned nonlinear dielectric element are provided. The pulse generating circuit stops operating due to the tube voltage drop at 7 after the discharge lamp is turned on, and the pulse filter circuit generates A? due to the operation of the nonlinear dielectric element. It is characterized by controlling the passage of pulses and non-passing control of high voltage pulses generated from the high voltage pulse generation circuit, the pulse width of which is narrower than the pulse width often generated by the operation of the nonlinear dielectric element. Discharge lamp lighting device.