JPH0329305A - High-frequency transformer - Google Patents

Abstract

PURPOSE:To restrain a reactive power from being generated, to reduce the number of processes, to simplify a manufacturing process and to reduce a cost by a method wherein a spiral pattern is wired on a printed sheet, one or a plurality of printed sheets are connected and a winding of a transformer is formed. CONSTITUTION:A primary winding 3 is wound on a core 1; in addition, insulating sheets 32 and printed sheets 33 are piled up alternately on it. The printed sheets 33 are connected to each other by using short-circuit leads 34 so as to be connected in series and in parallel; a secondary winding of a transformer is formed. Since a thickness of a pattern on the printed sheets 33 is thin, a capacity between the primary winding and the secondary winding can be reduced to several fractions to several tens of fractions as compared with that of conventional windings. Thereby, a reactive power generated by this capacity is reduced. As an assembly operation, the printed sheets 33 and the insulating sheets 32 are piled np and the printed sheets are connected by using the short-circuit leads 34; the number of winding processes can be reduced; a low cost can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a transformer operated at high frequency. [Prior Art] The winding structure of a split-winding transformer applied as a high-frequency transformer is shown in FIGS. 7 and 8. In the figures, 1 is a core;
A primary winding 3 is wound around this core 1, and a bobbin 2 with a divided winding part is placed over the primary winding, and 4 to 7 secondary windings are wrapped around the divided winding part. It is divided into and rolled.

The interlayer capacitance of each divided secondary winding 4 to 7 is calculated as C
5 to C8, and the capacitances between the primary winding 3 and the secondary windings 4 to 7 are C1 to C4, and the AC voltage applied to each capacitance is as shown in FIG.

The interlayer capacitance C of secondary windings 4 to 7 can be reduced by split winding.
Since the AC voltage applied to 5 to C8 is reduced to 1/2 of the number of divisions, the reactive power (1/2CV
”・f) becomes smaller by the square of the value.

In addition, since the reactive power is proportional to the operating frequency r, this structure is suitable for a high frequency transformer. It is said to be a construction.

[Problem to be solved by the invention]

However, in the conventional split-winding transformer, an AC voltage equal to the output voltage is applied to the capacitance CI-C4 between the primary winding 3 and the secondary windings 4 to 7, and in particular, this output voltage is high. In some cases, there is a problem in that a large amount of reactive power is generated.

Also, compared to the case where split winding is not performed, the lead wire insulating tubes 9 to 11 and the secondary interlayer insulating layer 13 shown in FIG.
28 and connection points 29 to 31, the number of man-hours for winding increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a high frequency transformer which can eliminate the disadvantages of the conventional example, can further suppress the generation of reactive power, and can be manufactured simply and inexpensively with fewer man-hours.

[Means to solve the problem]

In order to achieve the above object, the gist of the present invention is to wire a spiral pattern on a printed board, and connect one or more printed boards to form a winding of a transformer.

[Effect]

According to the present invention, the thickness of the printed board pattern is several 10
Since it is as thin as μm, the capacitance between the primary winding and the secondary winding can be reduced to several times to several tenths of that of a conventional winding (for example, IPEWφ0.5). As a result, the reactive power generated by this capacitance is also reduced.

Also, assemble the pudding B & insulation board. It is possible to simply stack the printed boards and connect them with shorting leads.

[Example〕 Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing one embodiment of the high-frequency transformer of the present invention, FIG. 2 is a plan view of the same, and FIG. 3 is a sectional view taken along line A-A in FIG. 3, and then cover the insulating plates 32 and printed boards 33 alternately.

Further, the printed boards 33 are connected to each other by shorting leads 34, so that they are connected in series or in parallel to form a secondary winding of a transformer.

This print Fi33, as shown in Figs. 4 and 5,
A spiral pattern 35 with a thickness of several tens of micrometers is wired on a donut-shaped plate 33a, and a through hole 36 is formed in the plate 33a.

By arranging the present invention in this manner, the interlayer capacitance of the secondary winding of the conventional transformer is eliminated, and the inter-turn capacitance C9 of the secondary winding and the mutual capacitance 1cIO, 1 of the printed board 33 are reduced.
There is only a capacitance Cll between the next winding 3 and the pattern 35. As a result, the AC voltage applied to each capacitor becomes as shown in FIG.

The inter-turn capacitance C9 of the secondary winding is small because the thickness of the pattern 35 is as thin as several 10 μm, and the applied voltage is small at 1/the total number of turns of the output voltage, so the reactive power generated by the inter-turn capacitance is also smaller than other reactive power. It is smaller than electric power.

The capacitance Cll between the primary winding 3 and the pattern 35 is larger than that of the pattern 35 compared to a conventional winding (for example, I P EW0.5).
Since the thickness of the capacitance is reduced to several times to several tenths, the reactive power generated by this capacitance is also reduced to several times to several tenths.

Note that since only 1 AC voltage corresponding to the number of divisions (number of printed boards) is applied to the capacitance CIO between the printed boards 33, reactive power is generated by the conventional secondary interlayer capacitance even if the number of divisions is the same. The reactive power is reduced to the same level as the reactive power. In particular, in the present invention, since the structure is such that the number of divisions (the number of printed boards 33) can be increased, the reactive power is reduced as a result.

Therefore, the total reactive power generated by the stray capacitance of the transformer can be reduced compared to conventional split-wind transformers.

In addition, as another example, when the secondary current is large,
The printed boards 33 may be connected in parallel. In this case, since no potential difference occurs in the capacitance CIO between the printed boards 33, no reactive power is generated due to this capacitance.

〔Effect of the invention〕

As described above, the high-frequency transformer of the present invention can suppress the generation of reactive power to a low level when operating at high frequencies, so the capacity of the high-frequency inverter on the input side of the transformer can be reduced, and the device can be made smaller. This is something that can be achieved.

In addition, compared to conventional products, insulation of connecting wires between divided windings and insulation between the eyebrows can be omitted, and it can be done by simply stacking the printed board and insulating board, which can significantly reduce the number of winding man-hours and lower costs. is also achieved.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing one embodiment of the high frequency transformer of the present invention, Fig. 2 is a plan view of the same, Fig. 3 is a cross-sectional view taken along the line A-A in Fig. 2, and Fig. 4 is a high-frequency transformer used in the present invention. Top view of printed board,
Fig. 5 is a sectional view taken along line B-B in Fig. 4, Fig. 6 is a potential distribution diagram of the secondary winding of the transformer of the present invention, Fig. 7 is a plan view of the conventional split winding transformer, and Fig. 8 is FIG. 7 is a sectional view taken along the line CC, and FIG. 9 is a potential distribution diagram of the secondary winding of a conventional split-winding transformer. 1...Core 2...Bobbin 3...1
Next winding 4-7... Secondary winding 8-12...
Lead wire insulation tubes 13 to 28... Secondary interlayer insulation 29 to 31... Connection points 32... Insulation plate 33
...Flint handle 33a...Plate 34.
・Short lead

Claims (1)

[Claims] A high-frequency transformer characterized in that a spiral pattern is wired on a printed board, and one or more printed boards are connected to form the winding of the transformer.