JPS63150894A - Discharge lamp lighter - 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] The present invention relates to a discharge lamp lighting device having an ignition circuit for lighting a discharge lamp with high-voltage pulses.

[Background Art 1 Figure 5 shows a specific circuit diagram of a conventional discharge lamp lighting device,
At the output terminal of the rectangular wave power supply 1 that outputs a rectangular wave voltage of both positive and negative polarities, there is a series circuit of a resistor 9 and a capacitor 5, and two large turns #a3b of a discharge lamp 2 and a pulse transformer 3.
The series circuits are connected in parallel. Also, resistance 9
From the connection point between the capacitor 5 and the bidirectional three-terminal thyristor 6 (this thyristor 6 constitutes the second switching element described in the embodiment), the capacitor 10, and the primary 8@3a of the pulse transformer 3. The capacitor 5, the thyristor 6, the capacitor 10, the primary winding 3a of the pulse transformer 3, etc. form a closed circuit. A capacitor 11 is connected in parallel to a series circuit between the discharge lamp 2 and the two large windings #113b of the pulse transformer 3. Further, a trigger circuit 8 for tribbing the thyristor 6 includes a capacitor 12, a resistor 13, and a switch element 14 made of an SBS. FIG. 6 shows an operation waveform diagram of FIG. 5, and the operation will be explained below.

FIG. 6(,) shows the output voltage waveform of the rectangular wave power source 1, and the capacitor 5 is charged by the output of the rectangular wave power source 1 via the resistor 9 as shown in FIG. 6(b). The thyristor 6 is turned on by the above-mentioned tri-four circuit 8, and the charge stored in the capacitor 5 is released in a closed loop of the capacitor 5, the thyristor 6, the capacitor 10, the primary winding 3a of the pulse transformer 3, and the capacitor 5. At this time, the pulse voltage generated in the primary winding 3a of the pulse transformer 3 is caused to generate a high voltage pulse in the secondary 8M3b according to the 8#i ratio of the pulse transformer 3. A voltage obtained by superimposing a high voltage pulse generated in the secondary winding 3b on the voltage across the capacitor 11 is applied to both ends of the discharge lamp 2. When the thyristor 6 turns on and the charge on the capacitor 5 is released, the capacitor 1
0 is charged, and when it becomes below the holding value 'Ili of the thyristor 6, the thyristor 6 is turned off and the capacitor 5 is charged again.

Figure 6 (1) shows the voltage waveform of the capacitor 5;
C) shows the voltage waveform of the capacitor 10, FIG. 6(d) shows the both voltages of the thyristor 6, and FIG. 6(e) shows the pulse voltage waveform generated in one large turn of the pulse transformer 3 @3a. It shows.

As shown in FIG. 5, the voltage difference between capacitor 5 and capacitor 10 is applied to thyristor 6. When the rectangular wave power supply 1 has a positive voltage, the capacitor 5 is repeatedly charged and discharged, and the thyristor 6 is repeatedly turned on and off, as shown in FIG. 6(b). When the polarity of the rectangular wave power supply 1 changes, a high voltage is applied to both ends of the thyristor 6, which is the voltage charged in the capacitor 10 in the previous half cycle and the voltage of the capacitor 5 added to the front terminal, so that after the polarity is reversed, When the thyristor 6 is turned on for the first time, the high voltage is applied to the primary winding 493a of the pulse transformer 3. As the thyristor 6 is repeatedly turned on and off, the voltage across the thyristor 6 (the voltage applied to the primary winding 93a of the pulse transformer 3) decreases, as shown in FIG. 6(d).

Now, in such a method, the conditions for making the discharge lamp 2 easier to light are: ■ Increasing the pulse height ■ Narrowing the pulse interval ■ Widen the pulse width ■ Increasing the number of pulses . In the circuit shown in Fig. 5, the above ■, ■
In order to satisfy the condition, it is possible to change the constants of the tri-four circuit 8 consisting of the capacitor 12, the resistor 13, and the switch element 14.
In order to increase the height of the pulse, it is necessary to shorten the time constant determined by the resistor 9 and capacitor 5. Further, from the viewpoint of widening the pulse width, the amount '8 of the capacitor 5 needs to be large, and in consideration of this, the resistor 9 has to be made small. However, if the resistance 9 is made smaller, a problem arises in that resistance loss increases.

[Objective of the Invention 1] The present invention has been provided in view of the above-mentioned points, and it is possible to improve the discharge lamp by increasing the pulse height, narrowing the pulse spacing, and widening the pulse width without increasing loss. The present invention provides a discharge lamp lighting device for the purpose of making it easier to light up a discharge lamp.

[Disclosure of the Invention 1 (Structure)] The present invention provides a discharge lamp lighting device that uses a rectangular wave power source as a power source to light a discharge lamp with high-voltage pulses. A series circuit with a secondary winding and a series circuit with a first switch element and a capacitor are connected in parallel, and a second switch element and a pulse transformer are connected at the connection point between the first switch element and the capacitor. A series circuit is connected with the primary winding of the capacitor, the second switch element, and the primary winding of the pulse transformer to form a closed circuit, and the first switch element is turned on when the square wave power source is turned on. In addition to forming a first trigger circuit for driving, after the first switch element is turned on, a second switch element is turned on by the charge charged in the capacitor, and a second trigger circuit is configured to turn on the discharge lamp via a nozzle transformer. By forming a trigger circuit of 2nd trigger circuit
The voltage applied to the capacitor increases to the voltage of the rectangular wave power supply by turning on the first switching element, so that the pulse height is not reduced. It is characterized by widening the pulse interval and pulse width.

(Example 1) Hereinafter, one example of the present invention will be described with reference to the drawings. Incidentally, since the overall configuration is substantially the same as the conventional one, the differences from the conventional one will be explained. As shown in FIG. 1, a series circuit consisting of a first switch element 4 consisting of a thyristor and a capacitor 5 is connected in parallel to the output terminal of the rectangular wave type a1 instead of the conventional resistor 9. The trigger circuit 7 for triggering is composed of a capacitor 15, a resistor 16, and a switch element 17 consisting of an SBS. Further, the trip circuit 8 of the thyristor (hereinafter referred to as a switch element) 6 and other configurations are the same as the conventional one. FIG. 2 is an operational waveform diagram of FIG. 1.

The operation will be explained below. The switch element 4 is turned on after the switch element 17 of the trigger circuit 7 breaks over, and the capacitor 5 is charged to the voltage of the rectangular wave power source 1 by turning on the switch element 4. This capacitor 5
Due to the charging, the switch element 14 of the tri-1 circuit 8 breaks over and turns on the switch element 6. After this switch cord 0 is turned on, the electric charge in the capacitor 5 is discharged to light the discharge lamp 2 as in the conventional case. After that, the same operation as before is repeated. At the same time that the switch element 4 is turned on, the voltage of the capacitor 5 rises to the power supply voltage, as shown in FIG. 2(b).

Then, the trigger circuit 8 is driven with this voltage, and a high voltage (
2(d)) is applied to the switch element 6, and when the switch element 6 is turned on, a pulse as shown in FIG. 2(e) is generated in the primary @ line 3a of the pulse transformer 3, and the discharge lamp Apply. When this is repeated, the voltage across the capacitor 10 increases, so that the voltage applied to the switch element 6 is subtracted and the voltage applied to the switch element 6 decreases as shown in FIG. 2 (J). and,
The pulse generated in the primary winding 3a of the pulse transformer 3 also becomes lower. In this way, the voltage of the capacitor 5 rises to the power supply voltage at the same time as the switching element 4 is turned on, so the voltage of the capacitor 5 can be increased to the power supply voltage at the same time as the switch element 4 is turned on, so that the voltage of the capacitor 5 can be increased to the power supply voltage as shown in FIG. As shown, the pulse interval and pulse width can be widened. Also, Figure 2 (
As shown in d), the height of the -th pulse can be increased. The arrow in FIG. 2(b) indicates when the switch cable 4 is on, and the arrow in FIG. 2(e) indicates when the switch element 6 is on.

(Embodiment 2) FIG. 3 shows another embodiment, in which a discharge resistor 18 is connected to the capacitor 10 in parallel.

While the switch element 6 is off, the capacitor 1 is
0 voltage is lowered and the voltage applied to the switch element 6 is increased. By doing this! @4 As shown in Figure (d), increase the pulse voltage for the second and subsequent shots.

Moreover, the number of pulses also increases. Incidentally, since the basic operation is the same and FIG. 4 corresponds to FIG. 2, the explanation of the operation will be omitted.

[Effects of the Invention 1] As described above, the present invention provides a discharge lamp lighting device that uses a rectangular wave power source as a power source and lights a discharge lamp with a high voltage pulse. A series circuit with the secondary winding of the transformer and a series circuit with the first switch element and the capacitor are respectively connected in parallel, and a switch element #IJ2 and a pulse are connected to the connection point between the switch element tIfJ1 and the capacitor. Connecting a series circuit with the primary winding of the transformer to form a closed circuit with the capacitor, the second switch cord, and the primary winding of the pulse transformer,
forming a first trigger circuit that turns on a first switch element when a rectangular wave power source is turned on, and turns on a second switch element using a charge charged in a capacitor after the first switch element is turned on; Since the second trigger circuit is formed to turn on the discharge lamp via a pulse transformer, the first trigger circuit turns on the first switch element, and by turning on the first switch element, the capacitor is turned on. increases to the voltage of the rectangular wave power supply, and then the second trigger circuit turns on the second switch element to light the discharge lamp, and the voltage applied to the capacitor increases to the voltage of the first switch element. By turning on the voltage of the rectangular wave power supply, the height of the pulse applied to the first switching element can be increased without increasing the resistance loss as in the conventional case. Since no resistance is used, the pulse does not rise with a time constant and rises to the power supply voltage at the same time as the first switching element is turned on. Therefore, the pulse interval can be narrowed without reducing the pulse height, and the pulse This has the effect of widening the range.

[Brief Description of the Drawings] Fig. 1 is a specific circuit diagram of one embodiment of the present invention, Fig. 2 is an operational waveform diagram of the same as the above, and fpJ3 diagram is the main point of another embodiment of the same. l
FIG. 4 is an operating waveform diagram of the same as above, FIG. 5 is a specific circuit diagram of the conventional example, and FIG. 6 is an operating waveform diagram of the same as above. 1 is a square wave power supply, 2 is a discharge lamp, 3 is a pulse transformer, 3
a is the primary winding, 3b is the secondary 84i, 4 is the first switch element, 5 is the capacitor, 6 is the second switch element, 7 is the first trigger circuit, and 8 is the second trigger circuit. . Agent Patent Attorney Ishi 1) Chief 7th 1IA Figure 3

Claims (1)

[Claims] (1) In a discharge lamp lighting device in which a discharge lamp is lit by high-voltage pulses using a rectangular wave power source as a power source, a discharge lamp and a pulse transformer are connected to the output end of the rectangular wave power source.
A series circuit with the next winding and a series circuit with the first switch element and the capacitor are connected in parallel, and the second switch element and the pulse transformer are connected at the connection point between the first switch element and the capacitor. A series circuit with the primary winding is connected to form a closed circuit with the capacitor, the second switch element, and the primary winding of the pulse transformer, and the first switch element is turned on when the square wave power source is turned on. In addition, after the first switch element is turned on, a second switch element is driven to turn on by the charge charged in the capacitor, and the discharge lamp is lit via a pulse transformer.
A discharge lamp lighting device characterized by forming a trigger circuit.