JPH031498A - Discharge lamp lighting device - Google Patents

Abstract

PURPOSE:To prevent stall of a lighted discharge lamp by furnishing an inductance element, connecting it with a main capacitor and the discharge lamp, and also connecting part of it in parallel with an aux. capacitor and a switch. CONSTITUTION:An inductor element 12 is connected in series to a main capacitor 5 and a discharge lamp 6, and at least a part of this element 12 is connected in parallel with an aux. capacitor 8 and a switch 7. This switch 7 is opened at the time of dimmed lighting, and electric power is supplied to the discharge lamp 6 through the element 12 and main capacitor 5. The switch 7 is shut at the time of full lighting, and power is supplied through a circuitry consisting of the element 12 and main capacitor 5 and a circuitry consisting of the switch 7 and capacitor 8. When the switch 7 is turned on, steep rise of the rush current is suppressed by the element 12 to prevent the electric charges in the main capacitor 5 from flowing into the aux. capacitor 8, which should cause stall of the lighted discharge lamp 6.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a discharge lamp lighting device for dimming.

(Prior art) As a conventional discharge lamp lighting device of this type, for example, a second
The configuration shown in the figure is known.

In Fig. 2, 1 is a leaky transformer for stage dimming, and this leaky transformer 1 has a common winding 2 and a series winding 3, and a commercial AC power source is connected between both ends of the common winding 2. 4 are connected. Further, a main capacitor 5 and a discharge lamp 6 are connected in series between the output ends of the leakage transformer 1, and a switch 7 and a sub-capacitor 8 connected in series are connected to the main capacitor 5 in parallel. It is connected.

FIG. 3 shows a circuit using a leaky transformer 11 for non-dimming, and the circuit shown in FIG. A choke coil 12 is provided to prevent flickering.

In both of the circuits shown in FIGS. 2 and 3, closing the switch 7 causes the discharge lamp 6 to be lit at full brightness, and opening the switch 7 causes the discharge lamp 6 to be dimmed.

(Problem to be Solved by the Invention) However, when switching from the dimmed lighting state of the discharge lamp 6 with the switch 7 open to the full-light lighting state by closing the switch 7, the main capacitor 5 is charged. When the charge is being discharged to the discharge lamp 6, the main capacitor 5
The current discharged from the discharge lamp becomes a circulating current through the sub-capacitor 8 and the switch 7, and no current flows to the discharge lamp 6.

In particular, so-called lamps with high metal vapor pressure, such as high-pressure mercury lamps, high-pressure sodium lamps, and metal halide lamps, have the problem of causing the lamps to go out.

Furthermore, in order to prevent this turning off, the secondary voltage must be increased.

Furthermore, the inrush current flowing from the main capacitor 5 to the sub capacitor 8 when the switch 7 is closed is very large, several tens of OA, so the contacts of the switch 7 are likely to weld, and when a relay switch is used as the switch 7, the contact capacity is This has the problem that a large item is required, and it is not possible to reduce the size and weight.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a discharge lamp lighting device that can prevent the discharge lamp from going out and can be made smaller and lighter.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a discharge lamp lighting device in which a main capacitor connected in parallel and a sub-capacitor having a switch in series are connected in series to a discharge lamp. An inductance element is connected in series to the lamp, and a small portion (at least a portion) of this inductance element is connected in parallel to the sub-capacitor and the switch.

(Function) According to the present invention, the switch is opened when the discharge lamp is dimmed and turned on, and the switch is closed when the discharge lamp is turned on at full brightness.

Then, when switching from a dimmed lighting state to a full-light lighting state, the switch is turned on and the current from the main capacitor is
When the current flows in the closed circuit of the sub capacitor and the switch, this current is suppressed by the choke coil, so that it is possible to prevent the current from ceasing to flow to the discharge lamp, and to suppress a circulating current with a large rise.

(Example) Hereinafter, an example of the discharge lamp lighting device of the present invention will be described with reference to the drawings. Note that parts corresponding to those shown in the conventional example will be described with the same reference numerals.

A commercial AC power supply 4 is connected to both ends of the common winding 2 of the leakage transformer 11.
A choke coil 1, which is an inductance element for preventing flickering during dimming, is connected between the output terminal of the leakage transformer 11.
2. Connect the main capacitor 5 and discharge lamp 6 in series.

Further, a switch 7 and a sub-capacitor 8 connected in series are connected in parallel to the choke coil 12 and the main capacitor 5.

Next, the operation of the above embodiment will be explained.

The voltage of the commercial AC power supply 4 is boosted by the leakage transformer 11 .

When dimming the light, open the switch 7 and close the choke coil 12.
Power is supplied to the discharge lamp 6 via the main capacitor 5.

Further, when all lights are on, the switch 7 is closed, and power is supplied to the discharge lamp 6 through the circuit of the choke coil 12 and the main capacitor 5 and the circuit of the switch 7 and the sub-capacitor 8.

Furthermore, when turning on the switch 7, the choke coil 12 suppresses the steep rise of the rush current.
The electric charge of the main capacitor 5 flows into the sub-capacitor 8 to prevent power from being supplied to the discharge lamp 6.

Furthermore, instead of connecting the entire choke coil 12 in parallel to the switch 7 and the sub-capacitor 8, it is also possible to connect only a part of the choke coil 12 in parallel by providing an intermediate tap or the like in the choke coil 12. good.

According to the above embodiment, the current flowing through the choke coil 12 is the same magnitude as the current flowing during full-light lighting in the case of the conventional circuit, but in the case of this embodiment, the current flowing through the choke coil 12 is the same magnitude as the current flowing during dim lighting. The light intensity is approximately 40 to 80% of that of full light, and the choke coil 12 can be made smaller and lighter. Note that the magnitude of the current varies depending on the dimming ratio, but is generally about 60%.

〔Effect of the invention〕

According to the present invention, a choke coil as an inductance element is connected in series with the main capacitor, and a switch and a sub-capacitor are connected in parallel with at least a part of the choke coil and the main capacitor. The lights can be prevented from going out, and the secondary voltage can therefore be lowered, so the transformer choke coil can be made smaller, and the inrush current that flows from the main capacitor to the sub-capacitor when the switch is turned on can be suppressed by an inductance element. Therefore, the connection capacitance of the switch can be reduced, thereby preventing the discharge lamp from going out and making it possible to reduce the size and weight.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the discharge lamp lighting device of the present invention, and FIGS. 2 and 3 are circuit diagrams showing conventional examples, respectively. 5. Main capacitor, 6. Discharge lamp, 7. Switch, 8
... Sub-capacitor, 12... Choke coil which is an inductance element.

Claims (1)

[Claims] (1) In a discharge lamp lighting device in which a main capacitor connected in parallel and a sub-capacitor having a switch in series are connected in series to a discharge lamp, an inductance element is connected in series to the main capacitor and the discharge lamp. ,
A discharge lamp lighting device characterized in that at least a part of the inductance element is connected in parallel to the sub-capacitor and the switch.