JPS6288295A - Burning apparatus of 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 the Invention] The present invention relates to a discharge lamp lighting device for starting and lighting a discharge lamp.

[Technical Background of the Invention] Conventionally, as this type of discharge lamp lighting device, one shown in FIG. 5 is known. A lighting power supply circuit 2 is connected to a commercial AC power supply 1, a starting circuit 3 is connected between the output terminals of the 'R power supply circuit, and a pulse transformer forming a part of this starting circuit 3 is connected. 31 secondary winding 3
The discharge lamp 4 is connected via 18. The starting circuit 3
A series time constant circuit consisting of a resistor 32 and a capacitor 33 is connected between the output terminals of the power supply circuit 2, and a semiconductor switch 34 as a constant voltage conduction element is connected to the capacitor 33 via the primary winding 31p of the pulse transformer 31. It is constructed by connecting in parallel.

In this device, when the power is turned on, charging of the capacitor 33 is started via the resistor 32, and when the charging voltage of the capacitor 33 reaches the breakover voltage of the semiconductor switch 34, the semiconductor switch 34 becomes conductive. Due to this operation, the charge in the capacitor 33 is discharged via the primary winding 31p of the pulse transformer 31, and the pulse transformer 31
A high voltage pulse voltage is generated in the secondary winding 31s and applied to the discharge lamp 4. This operation is repeated at a period determined by the time constant of the resistor 32 and capacitor 33 until the discharge lamp 4 lights up. When the discharge lamp lights up, the semiconductor switch 34 becomes non-conductive due to the drop in the voltage applied to the discharge lamp and starts. The operation of circuit 3 stops.

The voltage waveform applied from the starting circuit 3 to the discharge lamp 4 at this time of starting is shown in Figure 6, and energy is stored in the first cycle, and subsequent voltage waveforms are ringing. The energy is smaller in the waveform.

[Problems with the Background Art] By the way, in this device, when a high-pressure discharge lamp is used as the discharge lamp 4, if the discharge lamp is started when it is cold, the mercury or metal halide enclosed in the discharge lamp may be removed. Since the pressure is low, it is easy to start and light the discharge lamp with relatively low energy, but if you turn off the lit discharge lamp 4 and then restart it, you will have to start the discharge lamp 4 before it has cooled down yet. In such a case,
Since the pressure of the material sealed inside the discharge lamp is high, the lamp will not start and turn on unless a considerable amount of energy is supplied, but since the above device cannot supply such energy, it cannot restart and turn on the lamp instantly. There wasn't.

[Purpose of the Invention] This invention was made to solve such problems, and it is possible to always apply a high-voltage pulse voltage of sufficient height and energy to the discharge lamp from the starting circuit, and at the time of starting. Of course, it is an object of the present invention to provide a discharge lamp lighting device that can instantly start and light a discharge lamp even when restarting.

[Summary of the Invention] This invention includes a starting circuit that applies a high-voltage pulse to a discharge lamp;
In a discharge lamp lighting device, the starting circuit includes a first pulse generating circuit that generates a high enough pulse voltage to cause dielectric breakdown; a second pulse generating circuit that generates a high voltage pulse voltage that is delayed in time from the high voltage pulse voltage from the circuit and has sufficient energy to maintain the discharge; The pulse voltage is generated during the period from when the discharge lamp is dielectrically broken down by the high-voltage pulse voltage from the first pulse generation circuit until the ions within the discharge lamp disappear.

[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 lighting power supply circuit 12 is connected to a commercial AC power supply 11 to output a DC voltage. A starting circuit 13 is connected between the upper terminals which are the output terminals of the power supply circuit 12, and a high pressure discharge lamp 14 is connected via a secondary winding 131S of a pulse transformer 131 that constitutes a part of this starting circuit 13. ing.

The starting circuit 13 connects a series circuit of a resistor 132 and a semiconductor switch 133, which is a constant voltage conduction element, between the upper terminals of the power supply circuit 12, and connects the first primary winding of the pulse transformer 131 to the semiconductor switch 133. A series circuit of a capacitor 134 and a resistor 135 is connected in parallel via a line 131 CM to form a first pulse generating circuit. Further, a series time constant circuit consisting of a resistor 136 and a capacitor 137 is connected between the upper terminals of the power supply circuit 12, and a three-terminal thyristor is connected to the capacitor 137 via the second primary winding 131 p2 of the pulse transformer 131. 138 are connected in parallel to form a second pulse generation circuit. The thyristor 138 has its gate connected to the connection point between the capacitor 134 and the resistor 135.

The first pulse generating circuit is connected to the second pulse transformer 131.
The capacitor 1
34, the number of turns of the first primary winding 131p+, etc. are determined, and the second pulse generating circuit connects the high pressure discharge lamp 1 to the secondary winding 131S of the pulse transformer 131.
The capacitance of the capacitor 137, the number of turns of the second primary winding 131p2, etc. are determined so that a high-voltage pulse voltage having sufficient energy to maintain the discharge at the time of starting the motor 4 is generated.

When the power is turned on in the embodiment of the present invention having such a configuration, charging to the capacitor 134 is started via the resistor 132 and the first primary winding 131 px, and charging to the capacitor 137 via the resistor 136 is started. charging starts. Then, when the charging pressure of the capacitor 134 reaches the breakover voltage of the semiconductor switch 133, the semiconductor switch 133 becomes conductive and the charge in the capacitor 134 is discharged through the first primary winding 131px and the semiconductor switch 133, and the pulse transformer A high-voltage pulse voltage sufficient to cause dielectric breakdown of the discharge lamp 14 is generated in the secondary winding 131S of the coil 131 and applied to the high-pressure discharge lamp 14. Also capacitor 1
34 causes a pulse current to flow through the resistor 135, but since the first pulse current has a small pulse width, the thyristor 138 does not operate. The thyristor 138 conducts with a slight delay due to the oscillating current after the second round, and the charging current of the capacitor 137 is transferred to the second primary winding 1.
31 p2 and the thyristor 138.

As a result, a high-voltage pulse voltage having sufficient energy to maintain discharge of the discharge lamp 14 is generated in the secondary winding 131S of the pulse transformer 131, and is applied to the high-pressure discharge lamp 14.

As shown in FIG. 2, during startup, a high-voltage pulse voltage A with sufficient height to cause dielectric breakdown and a high-voltage pulse voltage port with sufficient energy are continuously applied to the high-pressure discharge lamp 14. As a result, the discharge lamp 14 causes dielectric breakdown at the high-voltage pulse voltage A and transitions to glow discharge, and then smoothly transitions from glow discharge to arc discharge at the high-voltage pulse voltage port at the time of starting and restarting. It will start and light up instantly regardless of the situation.

In this case, there is a restriction on the delay of the high-voltage pulse voltage port with respect to the high-voltage pulse voltage A, and the high-voltage pulse voltage port starts after the high-voltage pulse evening pressure A occurs as shown in FIG. 3(a). Considering the time it takes for voltage A to reach approximately its peak value (the dielectric breakdown of the discharge lamp 14 occurs near the peak value of high-voltage pulse voltage A), the glow discharge ends as shown in Figure 3 (b). The time t until the ions disappear
2 (time 1 is the glow discharge period). The time tl until the above-mentioned high-voltage pulse voltage A reaches approximately the peak value is determined by the primary winding 1311)t of the pulse transformer 131 and the resonance frequency of the capacitor 134, etc., and in this embodiment, it is 1 to 2 μm.
At this time, the dielectric breakdown of the discharge lamp 14 occurs and the purpose is fulfilled. Of course, the same effect can be obtained by setting the circuit constants so that the time t1 becomes even longer, but
Even in this case, it is better to generate the second pulse after dielectric breakdown. The reason for this is not only the startability of the lamp, but also the fact that in the circuit shown in FIG. 1, especially when the first and second pulse circuits are turned on at the same time, mutual pulse energy is absorbed, causing deterioration in starting and restarting.

In addition, regarding the time to, when approximately 0.5 J is applied as the first pulse energy in a metal halide lamp with a lamp power of 40 W, the effect of the second pulse decreases rapidly if it exceeds 10 μs. μs seems to be the limit in this example.

Therefore, the values of the timing circuit for timing each element of the second pulse generating circuit, particularly the thyristor 138 and the thyristor gate, are set so that the high voltage pulse voltage is generated within such a range.

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.

As shown in FIG. 4, this uses two pulse transformers, a first pulse transformer 141 and a second pulse transformer 142, in the starting circuit 13. That is, the second pulse transformer 14 is connected between the upper terminals of the lighting power supply circuit 12.
2 secondary IJ1142S and 1st pulse transformer 14
The high-pressure discharge lamp 14 is connected through the secondary winding 141S of 1 in series.

The starting circuit 13 also has a resistor 1 between the upper terminals of the power supply circuit 12.
43, a series time constant circuit of a capacitor 144 and a resistor 145 is connected, and the primary winding 1 of the first pulse transformer 141 is connected to the series circuit of the capacitor 144 and resistor 145.
A first pulse generation circuit is formed by connecting semiconductor switches 146 in parallel via 41p. Further, the starting circuit 13 connects a series time constant circuit of a resistor 147 and a capacitor 148 between the upper terminals of the power supply circuit 12, and connects the primary winding 142 of the second pulse transformer 142 to the capacitor 148.
Three-terminal thyristors 149 are connected in parallel via ρ to form a second pulse generation circuit. Said thyristor 1
49 connects its gate to the capacitor 144 and resistor 145.
connected to the connection point.

In this embodiment, when the power is turned on, the capacitor 1
44 and capacitor 148 are charged. First, the semiconductor switch 146 is controlled to be conductive, and the discharge of the capacitor 144 generates a high enough pulse voltage in the secondary winding of the first pulse transformer 141 to break down the discharge lamp 14, and is applied to the discharge lamp. . Subsequently, the thyristor 149 becomes conductive, and the discharge of the capacitor 148 causes the second
The discharge lamp 1 is connected to the secondary winding 142S of the pulse transformer 142 of
A high voltage pulse voltage having sufficient energy to maintain the discharge of 4 is generated and applied to the discharge lamp 14.

Therefore, this embodiment also provides the same effects as the previous embodiment.

In the above embodiment, the lighting of the discharge lamp is controlled by direct current, but the invention is not necessarily limited to this, and the lighting may be controlled by alternating current.

[Effects of the Invention] As detailed above, according to the present invention, a high-voltage pulse voltage of sufficient height and sufficient energy can always be applied to the discharge lamp from the starting circuit, and it is possible to apply a high-voltage pulse voltage of sufficient height and energy to the discharge lamp at all times, not only at the time of starting but also at the time of restarting. Also, it is possible to provide a discharge lamp lighting device that can instantaneously start and light a discharge lamp.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing an embodiment of the present invention, Fig. 2 is a diagram showing a pulse voltage waveform generated from a starting circuit in the same embodiment, and Fig. 3 is a diagram showing a pulse voltage waveform generated from a starting circuit in the same embodiment. FIG. 4 is a circuit diagram showing another embodiment of the present invention, and FIG. 5 is a conventional example. FIG. 6 is a diagram showing a pulse voltage waveform generated from the starting circuit in the conventional example. 12...Lighting power supply circuit, 13...Starting circuit, 13
1... Pulse transformer, 133... Semiconductor switch, 134.137... Capacitor, 138... 3-terminal thyristor, 14... High pressure discharge lamp. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 3

Claims (1)

[Claims] In a discharge lamp lighting device that includes a starting circuit that applies a high-voltage pulse to the discharge lamp to start the discharge lamp, and a circuit that maintains the lighting of the discharge lamp after starting, the starting circuit has a voltage that is high enough to cause dielectric breakdown. a first pulse generation circuit that generates a pulse voltage; and a second pulse generation circuit that generates a high voltage pulse voltage that is delayed in time from the high voltage pulse voltage from the first pulse generation circuit and has sufficient energy to maintain discharge. 2 pulse generating circuits, the high voltage pulse voltage from the second pulse generating circuit is applied to the discharge lamp after dielectric breakdown of the discharge lamp is caused by the high voltage pulse voltage from the first pulse generating circuit. A discharge lamp lighting device characterized in that the discharge lamp is generated during a period until the ions inside the discharge lamp disappear.