JPS6336125B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION An object of the present invention is to provide a discharge lamp lighting device in which the winding structure of a leakage transformer is improved so that stable filament heating can be performed.

A leakage transformer used for the output of this type of discharge lamp lighting device is formed by aligning the center of the input winding with the center of the filament winding, as shown in Figure 3 of the drawing of Utility Model Application Publication No. 53-32347. has been proposed. However, due to the leakage inductance of the transformer, there is a phase difference between the voltages generated between the output winding and the filament winding, which results in inconsistent heating of the filament, and in some cases, the filament spot of the discharge lamp may quickly The disadvantage is that it is not formed in a predetermined position. For this reason, it is known to wind a filament winding for filament heating on a common bobbin with the output winding, but in this case, the position of the filament winding is not considered and the filament winding is connected to the output winding. It is generally done to wind the wire at the beginning or end of the winding. In such a winding structure, the filament winding is wound at an arbitrary position rather than at a constant position with respect to the winding width of the output winding. This relationship will be explained with reference to FIGS. 1a and 1b. 1A and 1B both show the cross-sectional shape of the winding portion, and 11 is a winding bobbin around which an output winding 12 is wound. Reference numerals 13 and 14 indicate filament windings, which are wound around the winding start end and winding end of the output winding 12. 15 is a rolled up insulating paper that covers the surfaces of these windings.

Here, in FIG. 1A, one filament winding 13 is wound to the right in the figure from the center of the winding width of the uppermost layer of the output winding 12, that is, closer to the input winding (not shown). In FIG. 1b, one of the filament windings 13 is wound away from the center of the winding width of the uppermost layer of the output winding 12 away from the input winding. In this case, in the positional relationship shown in FIG. 1a, the voltage (V _f ) generated in the filament winding 13 advances in phase with respect to the voltage (V ₂ ) generated in the output winding 12, as shown in FIG. 2 a. In addition, in the positional relationship shown in Figure 1b, the voltage (V _f ) of the filament winding is as shown in Figure 2b.
has a phase lag with respect to the voltage of the output winding 12. In this way, if the winding position of the filament winding is different,
Since the phase of the voltage changes depending on the distribution of magnetic flux, the filament heating state is not constant, and in some cases, the filament spot of the discharge lamp may not be formed in the specified position quickly, which may shorten the life of the discharge lamp. be.

An object of the present invention is to wind the output leakage transformer so that the center of the winding width of the output winding and the center of the winding width of the filament winding coincide with each other, so that the voltages generated in both windings are in the same phase. The object of the present invention is to provide a discharge lamp lighting device that can perform stable filament heating.

The present invention will be described below with reference to an embodiment shown in the drawings. In Fig. 3, 21 is an AC power supply, 22
is a high frequency lighting circuit which receives the AC power supply 11 as an input and generates high frequency power, supplies it to the discharge lamp 23, and lights it at high frequency. High frequency lighting circuit 22
consists of a rectifier bridge 25 whose input end is connected to the AC power supply 21, and an inverter device 26.
The inverter device 16 also includes an output leakage transformer 28, a pair of transistors 29 and 30 that are push-pull connected via the input windings _28a and _28b of the leakage transformer 28, and emitters of these transistors 29 and 30 that are commonly connected. It has a constant current inductor 31 connected to the (-) side of the rectifier bridge 25, and a resonance capacitor 32 connected between both ends of the input windings _28a and _28b . Also,
The midpoint between the input windings 28 _a and 28 _b is connected to the (+) side of the rectifying bridge 25 and to the bases of the transistors 29 and 30 via a starting resistor 33, respectively. Furthermore, these bases are
It is connected to the base winding _28c wound around the leakage transformer 28.

When the inverter device 26 is started, one of the pair of transistors 29 and 30 is connected to the starting resistor 33.
and then the base winding 28 _c
The voltage induced in the pair of transistors 2
9 and 30 are controlled to alternately repeat on and off operations. This operation generates a high frequency output in the output winding 28 _d of the leakage transformer 28 and the filament windings 28 _e and 28 _f at both ends thereof, which heats the filaments 23 _F1 and 23 _F2 of the discharge lamp 23 and lights them at high frequency. let

FIG. 4 is a winding diagram of the leakage transformer 28, in which the input winding 28 is connected between terminals 1 and 2 and between terminals 2 and 3.
_a , 28 _b , base winding 28 _c between terminals 4-5, filament winding 28 between terminals 6-7 and 8-9
_e , _28f , and an output winding _28d between terminals 6-9.

FIG. 5 is a perspective view of the leakage transformer 28, and in the figure, 36 is an iron core, and the winding bobbin 3
7 through the input windings 28 _a , 28 _b and the output winding 28
A base winding 28 _c and filament windings 28 _{e and} 28 _f (not shown) are wound around some of these windings.

FIG. 6 is a sectional view of the output winding portion of the leakage transformer 28. As is clear from the figure, the filament windings 28 _e and 28 _f are provided at the bottom and top layers of the output winding 28 _d , and their winding width centers are mutually aligned with the winding width center of the output winding 28 _d . Wrap it so that it almost matches.

With this configuration, the filament winding 28
Since the voltages of _e and 28 _f and the voltage of output winding 28 _d are in the same phase, the heating state of filaments 23 _F1 and 23 _F2 is stabilized, and a filament spot is quickly formed immediately after lighting, and the discharge lamp The progress of blackening due to flashing can be significantly improved.

Figure 7 shows the relationship between the number of times the discharge lamp is lit and the progress of blackening.The line α is the center of the winding width of the filament winding and the output winding as described above, and the line β is the relationship between the filament winding and the output winding. When the winding is moved toward the opposite input winding side as shown in FIG. 1b, the line γ shows the case when the filament winding is moved toward the input winding side as shown in FIG. 1a.

Here, the lighting conditions for the above discharge lamp are: no-load secondary voltage 320 (V), no-load filament voltage 7.7 to 7.8
(V), filament preheating time is 1.5 (sec),
It was turned on and off repeatedly every 30 seconds.

As is clear from FIG. 7, under the same conditions as above, when the light is turned on using the leakage transformer of the present invention in which the centers of the winding widths are made to coincide with each other, the progress of blackening is significantly less than in other cases. Become.

In addition, in the above embodiment, the leakage transformer 28
is used as an output transformer for a high frequency lighting circuit, but it may also be used as an output transformer for lighting at a general commercial frequency. Furthermore, in the above embodiment, the case where one discharge lamp is lit is illustrated, but
Of course, the present invention can also be applied to lighting a plurality of discharge lamps.

As described above, according to the present invention, the filament winding of the leakage transformer that supplies lighting output to the discharge lamp and the output winding are wound so that their winding width centers coincide with each other, so that the voltage generated in both windings is are in the same phase, the heating state of the discharge lamp filament is stabilized, and as a result, the progress of blackening of the discharge lamp can be significantly improved.

[Brief explanation of the drawing]

Figures 1a and 1b are cross-sectional views showing the conventional winding structure;
FIGS. 2a and 2b are waveform diagrams showing the phase relationship of voltages generated in the winding structure shown in FIGS. 1a and 1b, and FIG. 3 is a circuit diagram showing an embodiment of the discharge lamp lighting device according to the present invention. , FIG. 4 is a winding diagram of the leakage transformer which is the main part of the present invention, and FIG. 5 is a perspective view of the same transformer.
Figure 6 is a cross-sectional view of the output winding section of the transformer;
The figure is a characteristic diagram showing the effects of the present invention in comparison with a conventional example. 21...AC power supply, 22...High frequency lighting circuit,
23...Discharge lamp, 28...Leakage transformer,
28 _d ... Output winding, 28 _e , 28 _f ... Filament winding.

Claims (1)

[Claims] 1. A leakage transformer having an AC power source, an input winding receiving input from the AC power source, an output winding and a filament winding magnetically coupled thereto, and an output of the leakage transformer. The leakage transformer includes a discharge lamp that is energized by the output of the winding and heats the filament by the output of the filament winding, and the leakage transformer is arranged such that the center of the winding width of the output winding and the center of the winding width of the filament winding are A discharge lamp lighting device characterized in that the devices are wrapped in a manner that coincides with each other. 2. The discharge lamp lighting device according to claim 1, wherein the leakage transformer is used as an output transformer of a high-frequency lighting circuit that receives an AC power source and generates a high-frequency output.