KR20020007098A - A high frequency power apparatus using a complete coupling transformer - Google Patents

Abstract

The present invention relates to a transformer for use in a high frequency power supply device and a pulse device, and more particularly, a transformer and a power supply using the transformer, in which the primary side and the secondary side are almost completely coupled while maintaining sufficient electrical insulation between the primary side and the secondary side. Relates to a device.

The present invention generally uses a transformer having a structure in which an outer core and an inner core are wound around a bobbin by winding the core and the inner core as the primary and secondary windings, respectively, using a coaxial cable widely used in the electric field.

In the present invention, because the coaxial cable is wound to make a transformer, the magnetic flux on the primary side is all bridged with the secondary side, so that perfect coupling is achieved, thereby providing a transformer having excellent transmission characteristics on the primary and secondary sides and no waveform distortion. It is possible to provide a power supply having excellent characteristics.

Description

High frequency power apparatus using a complete coupling transformer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer for use in a high frequency power supply device and a pulse device, and more particularly, to a transformer in which a primary side and a secondary side are almost completely coupled while maintaining sufficient electrical insulation between the primary side and the secondary side, and a power supply using the transformer. It is about.

In order to reduce the size of the power supply and improve performance, a high frequency power supply such as FIG. 1 (a) has been frequently used. However, in order to achieve electrical insulation and adjust the magnitude of the output voltage, such a high frequency power supply device winds the secondary coil 2 on the bobbin 6 as shown in FIG. 1 (b) and the primary coil on the wound secondary coil. A high frequency structure in which an insulating member 5 is provided to insulate between (1) and the secondary coil 2, the primary coil 1 is wound on the insulating member 5, and the core coil 1 is wrapped with a core 3. Although a high-voltage transformer has been used (sometimes the primary and secondary sides are changed), this high-frequency transformer must be spaced apart so that the primary coil (1) and the secondary coil (2) are electrically insulated. Magnetic leakage inevitably occurs between (1) and the secondary side coil (2).

In more detail, the conventional high frequency isolation transformer has incomplete coupling between the primary and secondary sides, and thus has leakage inductance and (stationary) capacitance between each winding as shown by the equivalent circuit of FIG. Due to the inductance and capacitance, the characteristics of the high frequency transformer are deteriorated. This phenomenon is larger as the winding ratios of the primary and secondary sides are larger, and the capacitance is larger. It can also be a missing factor. In particular, the problem with the high frequency transformer is that in the case of a power supply device requiring a pulse output as shown in FIG. 3, the output waveform is severely distorted with respect to the input, resulting in poor transmission characteristics between the primary and secondary sides, and even the signal size. When a large decrease occurs, it is difficult to generate a desired power supply state.

The present invention has been made to solve these problems, and an object thereof is to provide a fully coupled transformer that can be used in a high frequency power supply.

Another object of the present invention is to provide a power supply having good transmission characteristics using such a transformer.

It is still another object of the present invention to provide a high voltage or high current large power supply apparatus by properly arranging such transformers in series and in parallel.

1 is a high frequency power supply according to the prior art

Figure 2 is an equivalent circuit of a high frequency transformer of a high frequency power supply according to the prior art

Figure 3 is an input and output waveform of a high frequency transformer according to the prior art

4 is a structure of a fully coupled transformer according to the present invention

5 is a high frequency power supply using a fully coupled transformer of the present invention

6 is a high voltage power supply using a high frequency transformer according to the present invention

7 is a high voltage output transformer using a high frequency transformer according to the present invention

<Explanation of symbols for the main parts of the drawings>

1: Primary coil 6: Bobbin

2: secondary coil

3: core

5: insulation member

In order to achieve these objects, the present invention uses a coaxial cable, which is generally used in the electric field, as shown in FIG. 4 (b). As shown in FIG. A transformer having a structure in which the primary and secondary windings (which may be reversed) may be wound around the bobbin and wrapped in the core 3 as shown in FIG. 4 (a).

In this configuration, since the magnetic flux due to the current of the primary winding (outer core) of the coaxial cable wound on the core is interlinked with the secondary winding (inner core) (100%), the primary side and the secondary side are completely coupled. As a result, the frequency characteristics of the primary side and the secondary side of the transformer are very excellent, and especially when used as a pulse output transformer, the waveform is output without distortion of the waveform.

FIG. 5 is an embodiment of a high frequency power supply using such a transformer, and FIG. 6 is a view showing an output waveform with respect to an input pulse voltage when such a fully coupled transformer is used. As can be seen from FIG. 6, using the fully coupled transformer of the present invention, it can be seen that almost the same waveform is obtained without attenuation with respect to the square wave pulse input.

By the way, the fully coupled transformer of the present invention using a coaxial cable is difficult to use in a power supply device that wants a high voltage because the winding ratio of the primary winding and the secondary winding can be exactly one to one.

In this case, as shown in FIG. 7, a plurality of fully coupled transformers are used to connect the windings (outer cores) of the primary side of each fully coupled transformer in parallel, and the secondary windings (inner cores) are connected in series to easily output high voltage. You can get

Also, unlike FIG. 7, a plurality of fully coupled transformers are connected in series to the primary windings (outer cores) of each fully coupled transformer in series, and the secondary windings (inner cores) are connected in parallel, thereby easily providing a low voltage and high current power source. Get the device.

In the embodiment of the present invention, a coaxial cable is used, but a two-core flat cable may be used. In addition, although the primary and secondary sides of the cable are connected in series and parallel to a number of transformers using coaxial cables each having two cores to obtain a high contact voltage or a high current, the coaxial or general flat cable having three or more cores may be used. If one core wire is used as the winding of either the primary side or the secondary side, and the other core wires are the other windings, then the high voltage or high current power supply device mentioned above can be provided. For example, if you want to make a high voltage power supply with twice the input voltage using a 3-core coaxial cable with one outer core and two inner cores, make the two inner cores as the secondary side and one outer core as the primary side. If one end is connected so that the inner cores of the secondary side can be connected in series, and the inner cores of the other ends are used as both terminals of the secondary side, a high voltage corresponding to twice the input voltage can be obtained.

In the above description for convenience of description of the present invention to some extent in the form of specific embodiments, these descriptions are presented only as examples, those skilled in the art can be various modifications having a similar effect to the present invention without departing from the spirit and scope of the present invention. You will know.

In the present invention, because the coaxial cable is wound to make a transformer, the magnetic flux on the primary side is all bridged with the secondary side, so that perfect coupling is achieved, thereby providing a transformer with excellent transmission characteristics on the primary and secondary sides and without waveform distortion. It is possible to provide a power supply having excellent characteristics.

Claims (9)

And a part of the core of the cable having a plurality of cores as the primary winding, and a part or all of the remaining cores as the secondary winding to wind the cable. The transformer of claim 1, wherein the cable is a coaxial cable. The transformer according to claim 2, wherein the coaxial cable is composed of two cores of an inner core and an outer core, the inner core of which is the primary side, and the outer core of the core. The transformer according to claim 2, wherein the coaxial cable is composed of two cores of an inner core and an outer core, the inner core of which is a secondary side, and the outer core of the core. The transformer assembly according to any one of claims 1 to 4, wherein the primary side is connected in parallel and the secondary side is connected in series using a plurality of transformers. A transformer assembly comprising a plurality of transformers according to any one of claims 1 to 4, wherein the primary side is connected in series and the secondary side is connected in parallel. The transformer according to claim 1, wherein the cores on the primary side are connected in parallel, and the cores on the secondary side are connected in series to boost the input voltage in multiples corresponding to the number of cores on the secondary side. The transformer according to claim 1, wherein the primary current is connected in series and the secondary core is connected in parallel to increase the input current in multiples corresponding to the number of core wires on the primary side. The transformer of claim 1, wherein the cable is a flat cable.