JPS586296B2 - Ballast for discharge lamps - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ballast for a discharge lamp, and an object thereof is to improve the safety of the ballast.

In order to prevent disasters caused by abnormal temperature rises in discharge lamp ballasts or abnormal currents caused by interlayer short circuits, it is most common to incorporate thermal fuses, thermostats, etc. into the ballasts. However, when used for many years, there are problems such as a decline in functionality due to aging.

The present invention reduces the temperature rise due to the overall structure of the ballast,
Moreover, the present invention provides a disaster prevention ballast that prevents abnormal current from occurring even when an interlayer short circuit occurs between coils.

Figure 1 shows a top view a, a side view b, and a second view of an embodiment of the present invention.
The figure shows a plan view of the core.

In these figures, 1 is the main core, 2 is the outer core, and the coil 3 is divided into multiple pieces.
a, 3b, 3c, and 3d (the total number is 3) are wound around the main core 1 with gaps between them, and between each of these coils, there are multiple leakages that bypass the main core 1 and the outer core 20. Iron core 4a, 4
b, 4c are provided, and the divided coils 3a to 3d are entirely connected in series.

5 is a gap provided between the main core 1 and the outer core 2.

6 is the power supply side terminal of the coil 3, 7 is the discharge lamp side terminal, and the third
As shown in the figure, it is used by being connected to a discharge lamp 8, a glow lamp 9, and a power source E.

FIG. 4 shows another embodiment of the present invention in which the present invention is applied to a leakage transformer for a discharge lamp, in which a is a top view and b is a side view.

In this case, the primary coil 13 and secondary coil 14 of the transformer are each divided into a plurality of parts and wound around the main core 11 at intervals, and each of the divided primary coils 13a, 13b, 1
The main iron core 11 and the outer iron core 12 are bypassed between 3c (the entire primary coil is 13) and each divided secondary coil 14a, 14b, 14c (the entire secondary coil is 14). Multiple leaky cores 1 5 a , 1 5 b , 1
5c, 15d, and a leaky core 15e between the primary coil 13 and the secondary coil 140.

FIG. 5 shows a connection diagram between this leakage transformer and the discharge lamp 8.

As described above, in the present invention, the coil constituting one ballast is divided into a plurality of parts, each of the divided coils is wound around the main core at intervals, and leakage occurs between each of the divided coils. Since the iron core is embedded in the coil, the heat generated in the coil and main core is transmitted to the leakage core and radiated to the outside, so there is little temperature rise in the ballast.In addition, since the coil is divided into multiple parts, the heat generated in the coil and main core is radiated to the outside. The dielectric strength of the ballast may be low, which not only improves the safety of the ballast, but also reduces abnormal current when an interlayer short circuit occurs in the coil.

Next, the operation in that case will be explained.

FIG. 6a shows the coil and magnetic flux distribution in a normal state when a conventional ballast with no split coils and no leaky core between the coils is connected to a discharge lamp.

In this state, if an interlayer short circuit occurs in part n of the coil as shown in Figure C, the coil n that has experienced the interlayer short circuit will have a similar relationship to the secondary winding of the transformer with respect to the healthy part of the coil m. As a result, an abnormal current is generated in the opposite direction in the coil n as shown in FIG.

On the other hand, in the present invention, during normal operation, there are leakage magnetic fluxes φ1, φ2, φ3, and φ4 in addition to the main magnetic flux φ, as shown in figure d, but since each leakage magnetic flux is in the opposite direction, they are canceled out and 0.
It is.

If an interlayer short circuit occurs in the coil 3d in this state, most of the main magnetic flux φ from the healthy coil passes through the leaky core 4c and does not intersect with the coil 3d in which the interlayer short circuit has occurred, as shown in the figure e. The back electromotive force generated at 3d decreases,
Abnormal current is reduced and its temperature rise is suppressed, making it possible to prevent disasters.

In addition, although the above-mentioned embodiments are all examples of external iron type ballasts, the present invention can be implemented not only in the case of external iron type ballasts but also in internal iron type ballasts.

FIG. 7 shows an example of such a case.

In the figure, 20 is a main core, 21a to 21h are divided coils, and 22a to 22f are leaky cores inserted between each divided coil.

[Brief explanation of drawings]

Figure 1 shows a top view a, a side view b, and a second view of an embodiment of the present invention.
The figure is a plan view of the iron core, FIG. 3 is a connection diagram, FIG. 4 is a top view a and side view b of another embodiment of the present invention, FIG. 5 is a connection diagram thereof, and FIG. The operation explanatory diagram, FIG. T, is a sectional view of still another embodiment of the present invention. 1...Main core, 2...Outer core, 3a~
3d...Coil, 4a-4c...Leaky core.

Claims (1)

[Claims] 1 Divide each of the primary and secondary coils of a coil or leakage transformer constituting one discharge lamp ballast into multiple coils, and align each of the divided coils with the axis of the coil around one common main iron core. A discharge lamp comprising a plurality of divided coils arranged with gaps in the direction, a leaky core for bypassing the magnetic flux of the main core between each of these divided coils, and a plurality of divided coils connected in series. Ballast for use.