JPS588233B2 - High voltage generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a flyback transformer that is small but has good insulation properties.

Generally, the high DC voltage applied to the anode of a cathode ray tube of a television receiver is obtained by rectifying pulses generated by a flyback transformer using a rectifier.

There are two conventional devices of this type.

One is to increase the turn ratio between the primary and secondary windings of a flyback transformer to extract a larger pulse than the secondary winding, which is then rectified by a rectifier. The ratio between the primary winding and the secondary winding of the back transformer is not made too large, and the obtained pulses are multiplied and rectified.

However, in the former device, the amplitude of the high-voltage pulse is large even if the device is insulated with resin, so it is difficult to sufficiently suppress corona destruction.

In the latter case, corona damage can be easily avoided because the amplitude of the high-voltage pulse is not very large, but it becomes expensive because the multi-voltage rectifier circuit consists of multiple diodes and multiple high-voltage capacitors. The disadvantage of molding this on top is that it becomes extremely large.

The present invention aims to provide a flyback transformer free from such drawbacks, and will be described below with reference to FIGS. 1 to 7 showing embodiments of the present invention.

The flyback transformer of the present invention includes a flyback transformer 5 having a primary winding 1 and a secondary winding 2 as shown in FIG. The output terminal of the diode 4 is connected to the anode of the cathode ray tube 8 via the line 6, and the other end of the secondary winding is grounded via the rectifier diode 3.

According to the flyback transformer of the present invention having such a configuration, the alternating current electrical midpoint of the secondary winding 2 is at the center of the winding, and the amplitude of the pulse voltage generated in the secondary winding 2 is controlled by the rectifier 3.
% compared to the case without.

That is, the alternating current corona starting voltage is % of that without the rectifier 3.

Further, other embodiments of the present invention are shown in FIGS. 2, 3, and 4. In the example shown in FIG. 2, the secondary winding is divided into two, and one winding has 100 turns. The ratio is set to 902 times that of the other winding, and rectifying diodes 11 and 12 are connected between them, and in this case, the high voltage pulse is 1/3 that of the conventional one.

In addition, in the one shown in FIG. 3, the windings 13 and 14 have the same number of turns, and rectifying diodes 15 and 16 are connected between them, and in this case, the high voltage pulse is % of that of the conventional one.

Furthermore, in the one shown in FIG. 4, the secondary winding is divided into three parts, the windings 17 and 18 have the same turn ratio, and the number of turns of the winding 19 is half that of the windings 17 and 18. Diodes 20, 21, 22, and 23 are connected between each winding, and in this case, the high voltage pulse is 1/5 that of the conventional one.

Figure 5 shows the waveforms at points A, B, C, D, and X of the circuit in Figure 2.As is clear from Figure 5, the amplitude of the pulse is small, so the maximum This can be improved by taking insulation measures against pulses.

Therefore, in the present invention, as shown in FIG.
The secondary windings 9, 10 and diodes 4, 11, 12 are integrally molded with resin.

In addition, in the figure, 24 is a core, and 25 is a molded body.

Moreover, this FIG. 6 is an example corresponding to the circuit of FIG. 2.

FIG. 7 also corresponds to the circuit shown in FIG. 2, in which a capacitor 26 and a resistor 27 are connected to the connection point between diodes 11 and 12 to extract the focus voltage.

The capacitor 26 and resistor 27 are also integrally molded.

As described above, according to the present invention, although the amplitude of the high voltage pulse is small, the number of rectifying diodes is also small, and therefore the whole can be made compact by molding with resin. The distributed capacitance of the secondary winding becomes smaller, thereby increasing the high-order tuning frequency and further improving the electrical performance.

[Brief explanation of drawings]

1, AA, 3, and 4 are circuit diagrams of a flyback transformer according to an embodiment of the present invention, FIG. 5 is a waveform diagram of each part of the transformer shown in FIG. 2, and FIG. FIG. 7 is a sectional front view and a circuit diagram of the transformer. 1...Primary winding, 2, 9, 10, 13, 14,
17, 18, 19... Secondary winding, 4...
Rectifier diode, 11, 12, 15, 16, 20, 2
1, 22, 23... Rectifier diode, 25...
...Mold body.

Claims (1)

[Claims] 1. A first rectifier is connected to the high voltage side end of a secondary winding consisting of a single coil or a plurality of coils connected in series, and a first rectifier is connected to at least one of the remaining ends of the coil. 2 rectifier is connected, and the secondary winding and the
, a flyback transformer characterized in that the second rectifier and the primary winding are molded with resin.