JPS6110957B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides switching taps 4, 5, and 6 on the primary side and connects them between the first secondary output tap _t1 and ground 0 via a reactance element 2. The secondary output voltage corresponding to the rating of the discharge lamp 1 is outputted to the first secondary output tap _t1 , and as the number of turns of the switching taps 4, 5, and 6 to which the power source is connected increases,
A second secondary output tap _t2, which provides a lower output voltage, is provided on the secondary side.
A _discharge lamp lighting device is characterized in that it is equipped with a transformer 7 having a phase advance capacitor 3 connected between it and ground 0 for power factor improvement, and its purpose is to An object of the present invention is to provide a discharge lamp lighting device capable of lighting a discharge lamp and making the total input power factor high even in the case of each discharge lamp.

A conventional discharge lamp lighting device to which various discharge lamps can be connected is, for example, a discharge lamp 1 as shown in FIG.
A reactance element 2 consisting of a chiyoke coil is connected in series with the reactance element 2, and a phase advancing capacitor 3 for power factor improvement is connected in parallel to constitute a lighting circuit, and various discharge lamps 1 can be lit. Switch tap 4 to reactance element 2,
5 and 6, and were appropriately switched according to the discharge lamp 1 to be connected. However, in such a conventional example, since a constant leading phase current always flows through the power factor correction capacitor 3, the rated lamp current (lagging phase current) flowing through the discharge lamp 1
The drawback was that when the input power factor was small, the overall input power factor did not reach a high power factor.

The present invention has been provided in view of the above-mentioned drawbacks.
This will be explained below using an example circuit. FIG. 2 shows one embodiment, and 7 in the figure is an auto-type transformer, with power supply switching taps 4 and 5 provided between the input winding on the primary side, and both ends of the input winding. In other words, the ground side common terminal 0 and the tap 6 constitute a first power input terminal, and the ground side common terminal 0 and the power supply switching tap 4 or 5 constitute a second power input terminal. ing. In addition, a secondary output tap t ₁ is provided in the middle of the output winding on the secondary side, and the secondary output tap t ₁
A series circuit of a discharge lamp 1 and a reactance element 2 such as a chiyoke coil is connected between the terminal 0 and the common end 0 on the ground side, which constitutes one end of the output winding, and the common terminal 0 on the ground side constituting one end of the output winding. A capacitor 3 for power factor correction, which is a second reactance element whose current is in opposite phase to that of the reactance element ₂ , is connected between the tap t2 and the tap t2.

Now, when the lamp current Ila flowing through the discharge lamp 1 in Fig. 2 changes and the voltage applied to the discharge lamp 1 is V ₂ , the characteristics of V ₂ - Ila will be as shown in the curves A and R as shown in Fig. 3. , C is shown. Here, if a discharge lamp 1 of a certain rating is connected, and if the switching tap 4 is used as the primary side tap of the transformer 7 at that time, the ground side common terminal 0 and the power switching tap 4 are connected. For example, if the _rated voltage is applied between
Assume that the curve is obtained as an A curve. However, before the discharge lamp 1 is lit, the lamp current Ila ₁ does not flow through the discharge lamp 1, so a voltage of V ₂₁ is applied to the discharge lamp 1, and the discharge lamp 1 is lit.
After lighting, the discharge lamp 1 operates stably at point _O1 in FIG. 3 due to the relationship with the reactance element 2, which is a chiyoke coil. The lamp current Ila ₁ at this point O ₁ and the lamp voltage Vla ₁ are the rated lamp output = Ila ₁・Vla ₁・cos
The rated lamp current and voltage are the rated lamp current and voltage that give la ₁ (cosla ₁ indicates the lamp power factor). At this time, one input voltage is boosted and applied to the capacitor 3, so a large lead current flows, resulting in a high overall input power factor. Next, when the discharge lamp 1 is changed to one with a different type of rating, change the connection tap to 5 or 6. For example, use tap 6 to connect both ends of the input winding, that is, the common end 0 on the ground side. Assuming that the rated voltage is applied between the discharge lamp 1 and the reactance element 2, the voltage at the first secondary output tap _t1 , which is applied to the series circuit between the discharge lamp 1 and the reactance element 2, is stepped down to _V2 -
The Ila characteristic is, for example, as shown in curve C in Fig. 3.
That is, before the discharge lamp 1 is lit, a voltage of _V23 is applied to the discharge lamp 1, and the discharge lamp 1 is lit, and due to the relationship between the reactance element 2 and the discharge lamp 1, stable lighting operation is performed at point _O3 . If the switching tap 6 of the transformer 7 is set so that the lamp current Ila ₃ and lamp voltage Vla ₃ at this time become the rated lamp current and rated lamp voltage at that time, Vla ₃・Ila ₃・cosla ₃ The output given by is given to the discharge lamp 1. Since the lamp current Ila ₃ at this time is smaller than the lamp current Ila ₁ , in order to make the total input power factor a high power factor, it is necessary to reduce the current flowing through the capacitor 3 compared to the previous case, but the input winding Tap 6, which is one end of
Since the turn ratio with tap t ₂ , which is one end of the output winding, is 1, the rated input voltage is only applied to the capacitor 3, the lead current decreases, and the input This allows the power factor to be maintained at a high power factor.

FIG. 4 shows another embodiment of the invention, which embodiment includes a starting aid 8. As shown in FIG. That is, when the tap 6, which is one end of the input winding of the transformer 7, is used, the voltage applied to the discharge lamp becomes as low as V ₂₃ before the discharge lamp 1 lights up, as shown in Fig. 3, and starts. It may be difficult. For this purpose, starting aid device 8
A small capacitor constituting the capacitor is inserted between the tap _t2 , which is one end of the output winding, and the connection point between the discharge lamp 1 and the reactance element 2 to compensate for starting. Of course, you can use a resistor instead of a capacitor,
Of course, a starting assist device 8 using an electronic circuit may also be used. FIG. 5 shows another embodiment of the present invention, in which a transformer 7 consisting of a so-called leakage transformer in which a transformer and a reactance element are integrated is used. Of course, a preheating type discharge lamp may be used as the discharge lamp 1.

In the present invention, a power supply switching tap is provided in the middle of the input winding, both ends of the input winding are used as first power input terminals, and one end of the input winding and the power supply switching tap are used as second power supply input terminals. In addition, a series circuit including a transformer having an output tap in the middle of the output winding, a first reactance element and a discharge lamp load connected between one end of the output winding and the output tap, and the output winding. A second reactance element is connected to both ends of the reactance element and has a current flowing in opposite phase to the first reactance element, and when the discharge lamp load has a small lamp current, the discharge lamp is connected to the first power input terminal. If the lamp load has a large lamp current, the second
AC power sources are selectively connected to the power input terminals of the lamp, so the discharge lamp can be lit by simply changing the tap on the input winding side to which the power source is connected depending on the type of discharge lamp. , it is compatible with various discharge lamps, eliminates the need for diversification of devices, and facilitates inventory management.In addition, the first reactance element and discharge lamp load connected between one end of the output winding and the output tap are A series circuit is provided, and a second reactance element is connected to both ends of the output winding, and the energizing current is in opposite phase to the first reactance element. In the case of discharge lamps that require a high starting voltage applied by using a power supply switching tap with a small number of turns, a large lead current can be obtained; conversely, for discharge lamps with a small rated lamp current, in other words, by using a switching tap with a large number of turns, a low starting voltage can be obtained. In the case of voltage discharge lamps, the advance current can be kept small, and the total input power factor can always be set to a high power factor depending on each discharge lamp.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a conventional example, FIG. 2 is a circuit diagram of an embodiment of the present invention, FIG. 3 is an explanatory diagram of the same operation as above, FIG. 4 is a circuit diagram of another embodiment of the present invention, Figure 5 is a circuit diagram of another embodiment of the present invention, where 0 is ground, 1
is a discharge lamp, 2 is a reactance element, 3 is a capacitor, 4 and 5 are power supply switching taps, 6 is a tap, 7 is a transformer, _t1 is a secondary output tap, and _t2 is a tap.

Claims (1)

[Claims] 1. Provide a power supply switching tap in the middle of the input winding, use both ends of the input winding as the first power input terminal,
Connect one end of the input winding and the power switch tap to the second
A series circuit of a transformer having a power supply input terminal and an output tap in the middle of the output winding, a first reactance element connected between one end of the output winding and the output tap, and a discharge lamp load. and a second reactance element which is connected to both ends of the output winding and whose energizing current is in opposite phase to the first reactance element, and when the discharge lamp load has a small lamp current, the first reactance element A discharge lamp lighting device characterized in that an AC power source is selectively connected to a second power input terminal when the discharge lamp load has a large lamp current.