JPS58163197A - 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 the Invention] The present invention ignites a switching element connected in parallel to a discharge lamp, thereby applying voltage to the lamp to control starting and lighting of the lamp. The present invention relates to a discharge lamp lighting device having a control circuit.

[Technical background of the invention and its problems]

Conventionally, this type of discharge lamp lighting device has 1. As shown in the IF1 diagram, connect the AC power supply (1) to the fang 1 inductor (2) [
A discharge lamp (3) is connected, and a preheating circuit (4) and a starting lighting control circuit (5) are connected in parallel to this lamp (3). This control circuit (5) is connected to the fan 2 inductor (6
) and capacitor (7) as two switching elements connected in parallel in different orientations CR (8) (9)
When a signal voltage is output from the pulse transformer 01) of the signal generating circuit 00) described later, the primary winding (11a) and the secondary winding (11) of the pulse transformer (11)
+) and 'l i, i -W (J3Q3wosuke1.teS
CR (8) (9) node K ([! voltage is applied,
sCR(8)(9) are fired alternately every half period of the power supply voltage. At this time, the impedance of the lamp (3) is close to infinity, and it becomes a series resonant circuit of the inductor (2) of fang 1 and the capacitor (7) via the s CRs (8) and (9) in series, and the capacitor (power is charged to a value close to the peak value of the power supply voltage.By repeating this operation several cycles, the charging voltage of the capacitor (7) increases rapidly, and this voltage is applied across the lamp (3). When this voltage reaches the starting voltage of the lamp (3), the lamp (3) starts or glow discharges.Then the lamp (3)
transitions to arc discharge, and the lamp (3) lights up. After lighting, the impedance of the lamp (3) decreases, so the voltage across it also decreases, and the capacitor (7)
), and on the other hand, the lamp current flows through the inductor (2) of 1. The Jll inductor (2) functions exclusively as a ballast. This causes the lamp (3) to continue lighting.

In addition, the inductor (6) of spear 2 connected in series with 80 R (8) (9) is a capacitor (which suppresses the electric charge from being discharged into the lamp (3) at the time of starting or re-igniting, This is to prevent flickering caused by repeated charging and discharging operations of the capacitor (7).

The signal generating circuit α1 includes a rectifier (I5, transistor a
Consisting of the Q1 constant voltage element αη, the primary winding (11, l) of the pulse transformer αυ, and the resistor (181 (11), as the power supply voltage increases based on the AC waveform, the voltage across the resistor 08 increases as the voltage across the constant voltage element αη increases. Voltage across both ends VB becomes more dog, and when transistor 0υ is turned off, pulse transformer αυ 1
The configuration is such that a signal voltage is generated in the next winding (11a).

In the configuration of this conventional example, sCR (8) and (9) are ignited at the same phase angle φ with respect to the power supply voltage both when starting and lighting the lamp (3), so that with respect to the power supply voltage vi, The voltage vL across the lamp (3) is in the state shown in Figure 6.

When lighting the lamp (3) with such a lighting device,
As shown in Figure 8, the power supply voltage v4 changes from 90V to 110V.
In the range of , that is, the fluctuation range of a normal commercial power supply of 100 V, the ignition phase angle φ at the time of lighting becomes maximum near the insulator, and the output illuminance/input power [1-Vvi, l becomes maximum. Furthermore, as shown in Figure 9, the power factor P7 increases as the firing phase angle φ becomes smaller. In this way, the best ignition phase angle φ at the time of lighting is around π4.

However, as shown in FIG. 7, when the input voltage virL is 100 V or less, there is a problem that flickering occurs when the firing phase angle φ2 during timing is set to be less than or equal to .

Therefore, if the ignition phase angle φ of s CR (8) (9) is set to a value that is efficient when lighting, flickering will occur when starting.
If the value is set to a value that does not cause flickering during startup, there is a drawback that efficiency decreases when the lights are turned on.

Also, JP-A-52-18256! There is also known a device described in the US Patent Publication No. 1, but this also has the same drawback because the phase angle for controlling the opening of the switching element is the same at the time of starting and at the time of lighting.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned drawbacks, and it is an object of the present invention to provide a discharge lamp lighting device that can eliminate flickering during startup and improve lighting efficiency during lighting.

[Summary of the invention]

The discharge lamp lighting device of the present invention comprises an AC power source, a discharge lamp connected to the power source via an inductor 1, and a series circuit including an inductor 2 connected in parallel to the lamp, a capacitor, and a switching element. 1. A signal generation circuit that generates a signal to turn on the switching element every half cycle of the power supply, and generates the signal at a phase angle that is delayed when starting the lamp compared to when the lamp is lit. With a configuration characterized by having a circuit,
The ignition phase angle of the switching element is changed between starting and lighting, and the lamp is ignited at the optimal phase angle for each of lamp starting and lighting.

[Embodiments of the invention]

Next, one embodiment of the present invention will be described based on Figures 2 and 8. The circuit shown in Figure 2 is the signal generation circuit 0I.
) are the same as the circuit shown in FIG.

The signal generating circuit 01) is as follows. (A) is a rectifier, and a series circuit is connected between the (+) output terminal of this rectifier 4 and (→output terminal is a resistor (C) and a constant voltage cable 04), and the connection point is a transistor Q1. It is connected to the base of The collector of this transistor (C) is connected to the (+) output terminal via the primary winding (11a) of the pulse transformer Ql), and the emitter is connected to the (→ output terminal) via the resistor (A).
It is also connected to the anode of the BCB@ via a resistive end. The cathode of this 8CR (to) is a diode (
The gate is connected to the (c) output terminal via the resistor (7), and the gate is connected to the (+) output terminal via the resistor (7), and to the 7 node of 8CR01J of spear 2. The cathode of this second 5CRCIυ is connected to (→output terminal), and the gate is connected to (→output terminal) through a parallel circuit of capacitor 0a and resistor (c). It is connected to the.

Next, the operation of this embodiment will be explained.

When the power supply voltage is applied, the preheating circuit (4) is turned on for approximately α5 seconds, and the lamp (3) is heated through this preheating circuit (4).
A current flows through both filaments, preheating them. After this preheating is completed, the CRs (8) and (9) are ignited once every half cycle as explained in the conventional example, and the charging voltage of the capacitor (7) remains constant until the lamp (3) starts. The voltage becomes high when the engine starts, and the voltage remains constant after starting.

When this voltage is applied, the lamp (3) starts discharging,
The discharge is maintained for half a cycle of the supply voltage.

The signal for turning on SCR (8) (9) is generated from the signal generation circuit (01);
The operation of 2]) is as follows.

After the preheating circuit (4) finishes preheating, the voltage shown in Figure 3 (α) is output from both output terminals of the rectifier (22).

Looking at one waveform of this output voltage, first of all, during the initial period, the voltage vR between the emitter of the transistor (c) and (→output terminal) is lower than the voltage across the constant voltage element (goods), so the transistor (c) is on. Then, when this voltage vR becomes higher than VBO, which is the conduction voltage of constant voltage element 04), the base-emitter voltage of the transistor (2ω) becomes 0, and the transistor (c) turns off, and this off operation When the pulse transformer αυ operates, the secondary winding (114
), a signal voltage is generated which becomes the firing signal for sCR(8)(9).

The voltage vR is determined by the resistance value R connected between the round tip of the transistor (c) and the output terminal (→output terminal), the emitter current IE, and K. Since the charging voltage of the capacitor country is O, ?
gcR3υ of 2 is off, so 8 of fang 1
CRI:l! l is on.

Then, a parallel circuit consisting of a resistor (A) and a resistor Qη is connected between the emitter of the 5CR (transistor because 2119 is on) and the output terminal (→ output terminal). Then, if the value of this resistance example (5) is R,, R, and I R2, the resistance value R-□ is obtained, and the voltage R10R2 at this time is R, R2 ■R4-□1+R2■□, --- −−−−−−−
-----------(1).

Also, after a predetermined period of time has passed after the completion of preheating, the capacitor (T)
Charging progresses, and as a result, 5CR (3υ) of spear 2 is turned on, and 8CR (to) of spear 1 is turned off.Then, between the emitter of transistor (c) and the output terminal (f) Only the resistor (a) will be connected, and the resistance value R
The voltage vR4 at this time is VH2-R4
! Bird, −−−−−−−−−−−−−−−−−−
-----(2).

That is, in order for vBO to become ``VH2'' and VH4, it must be changed, and as is clear from the circuit configuration, as the output voltage Vi% shown in Fig. 8 (α) increases, the duck also becomes a dog.
The voltages vR1 and vRl are as shown in Figure 8 (4) (1). Therefore, the time at which the transistor (c) is turned off and the ignition signal is generated is delayed to 5 at startup, which is the case immediately after preheating is completed, within one waveform, as shown by the solid line in Figure 8 (d). , and the phase angle becomes large. In addition, when turning on, which is when a predetermined period of time has elapsed after the completion of preheating, the
) as shown by the broken line, the phase angle becomes smaller.

In this way, the ignition phase angle of s CR(s) (9) is large when the lamp starts, and becomes small when the lamp is lit. I can do something.

Next, another embodiment of the present invention will be described. It should be noted that in Figures 4 to 7, only the signal generating circuit (2υ) is shown, and the same parts as in Figure 8 are given the same reference numerals and the explanation will be omitted.

In figure 4, PNP) transistor (t), capacitor (to) and resistor 071 c181C1! j (4(l
When starting, the capacitor (to) is not charged, so the transistor (to) is turned off, and only the resistor is connected to the circuit, and when lighting, the capacitor is charged, so the transistor (to) is turned off. The field will be turned on, and the parallel circuit of the resistor Og decoy will be connected. In this way, the resistance value connected between (g) the output terminal and the base of the transistor (c) is large at the time of starting, and small when the lamp is lit. Therefore, the phase angle at which the transistor (C) is turned off and the ignition signal is generated is large at the time of starting, and small at the time of lighting, as in the case of the embodiment shown in FIG.

Also, in Figure 5, 5CR (4IJ and capacitor (
4 resistances (43 and 2 constant voltage elements (24a) (2
When starting, the capacitor (42) is not charged, so the SCR (411 is turned off, and the two constant voltage elements (24) are connected to the circuit, and the light is turned on. The time is 8 because the capacitor (4z is charged)
CR (4υ turns on and one constant voltage element (24a)
will be connected to the circuit. By changing the number of constant voltage elements (24,) (2) connected between the base of the transistor (c) and the output end of the transistor (c) in this way,
The value of voltage vB0 shown in Figure 8 becomes high when starting, and becomes low when lighting. Therefore, the phase angle at which the transistor (C) is turned off and the firing signal is generated is as shown in Figure 2 in Example 1.
As in the case of , it is large when starting, and becomes small when lighting.

The values shown in Figures 6 to 9 are for the case where a 40W lamp is used as the discharge lamp (3) and one lamp is lit. In this case, as can be seen from each figure, the ignition phase angle φ of 8CR (8H9) is approximately r5w/s at the time of starting, and approximately π at the time of lighting.
It is only necessary to determine each constant of the 5-signal generating circuit 0υ so that the value becomes 4.

Note that in the above embodiment, a time constant circuit is used to measure time to distinguish between starting and lighting, and the phase angle of the ignition signal is varied; however, the configuration is not limited to this, and the lamp Of course, it is also possible to adopt a configuration in which the current, lamp voltage, light output, etc. are detected to distinguish between starting and lighting.

Furthermore, the switching elements are not limited to SCRs (8) and (9), and triacs and transistors may also be used.

〔Effect of the invention〕

According to the present invention, when starting a discharge lamp, by igniting the switching element at a phase angle that is delayed from when the lamp is lit, it is possible to start the lamp reliably, prevent flickering, and furthermore, the lamp is lit. In some cases, it is possible to improve the input power factor and the luminous efficiency, and furthermore, it is possible to minimize the decrease in each efficiency due to Kmm electric voltage fluctuations, and the fluctuation characteristics can also be improved.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a conventional discharge lamp lighting device, Figure 2 is a circuit diagram showing an embodiment of the discharge lamp lighting device of the present invention, Figure 3 is an explanatory diagram of the same operation, Figures 4 and 5 are Figures 1 and 1' are circuit diagrams showing other embodiments of the present invention. Figures 1 and 1'F6 to 9 are characteristic diagrams showing various characteristics of the discharge lamp lighting device. (1) Reference AC power supply, (2) Inductor 1, (
3) E medium discharge lamp, (5)・War start lighting control circuit, (
6)...Spear 2 inductor, (force - capacitor, (8
+(9)...8CR as a switching element, (21
)・-Signal generation circuit. 5th ¥B

Claims (2)

[Claims] (1) Startup formed by a series circuit consisting of an AC power source, a discharge lamp connected to this power source via an inductor 1, and an inductor 2 connected in parallel to this lamp, a capacitor, and a switching element. A lighting control circuit; and a signal generation circuit that generates a signal to turn on the switching element every half cycle of the power supply and generates the signal at a phase angle that is delayed when starting the lamp compared to when the lamp is lit. Characteristic discharge lamp lighting device. (2) The discharge lamp lighting device according to claim 1, wherein the signal generating circuit distinguishes between starting time and lighting time by measuring time from the time when voltage is applied.