CN1211816C - High-voltage transformer with strong coupling - Google Patents

Abstract

The invention provides a high-voltage transformer. The traditional high-voltage transformer has two problems of insulation and coupling. The present invention provides a high voltage transformer comprising: the high-voltage side winding is wound on the framework, the maximum height of a window of the framework is shown as a right formula (I), and the minimum width (W) of the window is shown as a right formula (II); wherein N represents the total number of turns of the high-voltage side winding, V_limIs the maximum withstand voltage value of the wire of the high-voltage side winding, D represents the wire diameter of the wire of the high-voltage side winding, V_maxRepresenting the maximum voltage across the high side winding.

Description

A High-voltage Transformer with Strong Coupling

The invention relates to a transformer, in particular to a high-voltage transformer with strong coupling.

In driving circuits such as backlights, a transformer that generates high voltage is often required. Due to its large turn ratio (hundreds or even thousands), the high-voltage side winding has a large number of turns and a high voltage, so there are two major difficulties in insulation and coupling.

Traditional high-voltage transformers generally adopt the following structure:

1. The most traditional bobbin and winding method

The most traditional coil bobbin and winding method are shown in Figure 1, where the arrows indicate the winding sequence. The specific winding method is to first take 101 as the starting point of the winding, wrap a layer of wires to the right, and then start to wind the second layer to the left above the end of the first layer of wiring (wire 102), so Wind the remaining layers of wire back and forth. Obviously, when the wiring length W0 of each layer is too large, the voltage difference between the starting point wire of one layer and the termination point wire of the adjacent layer (such as wires 101 and 103 in Figure 1) may be very large. High, exceeding the requirements of safety regulations, especially when the voltage of the winding is high. Therefore, this bobbin and winding method are not suitable for high-voltage windings.

2. Oblique raving method

Figure 2 shows a traditional winding method suitable for high-voltage applications—the oblique winding method. The winding sequence is shown by the arrow in Figure 2, and the maximum voltage difference between layers is only related to the width W1 of the oblique winding. However, if the traditional winding method shown in Figure 1 is used, the voltage difference between layers is related to the width W0 of the coil bobbin. When W0 is too large, the insulation requirements cannot be met. Due to the coil bobbin height of the oblique winding method, the appropriate oblique winding width W1 can be considered in the design, so as to ensure the interlayer insulation requirements. However, the oblique winding method has high requirements on the winding process, especially when the winding is very thin, it is easy to appear the phenomenon of slipping, so the scrap rate is high, which affects the production efficiency.

From the perspective of the traditional technology introduced above, it is difficult for the traditional transformer structure to ensure the winding insulation requirements, because the voltage between layers will exceed the allowable voltage of safety regulations, resulting in insulation breakdown failure.

Therefore, the object of the present invention is to provide a novel high-voltage transformer, which can effectively solve the insulation problem in the high-voltage winding of the high-voltage transformer, and at the same time ensure better coupling between the primary and secondary windings.

According to the above purpose of the present invention, the high-voltage transformer provided by the present invention includes: a magnetic core, a skeleton, a high-voltage side winding and a low-voltage side winding, the skeleton is flat, the high-voltage side winding is wound on the skeleton, and the skeleton The maximum height (H) of the window is $h=\mathrm{Dn}=\frac{N{V}_{\lim }\mathrm{D.}}{2V_{\max }},$ The minimum width (W) of the window is $W=\frac{N}{\mathrm{no}}\mathrm{D.}=\frac{2V_{\max }\mathrm{D.}}{V_{\lim }};$ In the formula, N represents the total number of turns of the high-voltage side winding, V _lim is the maximum withstand voltage value of the wire of the high-voltage side winding, D represents the wire diameter of the wire of the high-voltage side winding, and V _max represents the high-voltage side winding The maximum voltage across the side winding.

As mentioned above, since the frame of the high-voltage transformer of the present invention adopts a flat shape, and the maximum height of the frame is limited according to the maximum withstand voltage value of the wire, it can be ensured that the maximum voltage difference between the adjacent layers of the high-voltage side winding is within the range of the wire. Under the maximum withstand voltage value, it can better solve the insulation problem of high-voltage transformers.

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. Through the following embodiments, the above and other features, advantages and effects of the present invention will become more apparent.

In the attached picture:

Figure 1 is a schematic diagram of the coil skeleton and winding method of a traditional transformer;

Fig. 2 is a schematic diagram of a traditional oblique winding method;

Fig. 3 is the structural representation of high-voltage transformer of the present invention:

Fig. 4 shows a schematic perspective view of the high-voltage transformer shown in Fig. 3, wherein, in order to better illustrate its structure, the magnetic core is not drawn;

Fig. 5 is a schematic diagram of the high-voltage side winding skeleton of the high-voltage transformer of the present invention.

As shown in FIG. 3 , the high-voltage transformer of the present invention includes a bobbin 1 , a high-voltage side winding 2 wound on the bobbin 1 , a low-voltage side winding 3 located above the bobbin 1 , and a magnetic core 4 . The structure of the magnetic core 4 can be a traditional EI type magnetic core (as shown in FIG. 3 ), or it can also adopt structures such as an EE type magnetic core, an RM type magnetic core, and a PJ type magnetic core.

The low-voltage side winding 3 can adopt a traditional winding method, that is, another bobbin is used to wind the low-voltage side winding. In order to strengthen the coupling degree between the low-voltage side winding and the high-voltage side winding, in this embodiment, as shown in Figure 4, it is realized by using a single-sided or double-sided printed circuit board, and several turns are engraved on the printed circuit board (the The number of turns can be determined according to the voltage transfer ratio of the transformer) copper foil, as the low-voltage side winding. If a double-sided board is used, several turns of copper foil can be engraved on both sides of the printed circuit board as a low-voltage side winding. The printed circuit board engraved with several turns of copper foil is placed above the bobbin 1 on which the high-voltage side winding 2 is wound (that is, placed close to the bobbin 1 ). In this way, the coupling degree between the low voltage winding and the high voltage winding can be improved.

In another embodiment, the low-voltage side winding may also use pie-shaped flat copper foil windings, and place it close to the skeleton on which the high-voltage side winding is wound. This structure can also ensure strong coupling between the primary and secondary windings.

The key point of the present invention lies in the structure of the skeleton 1 . As shown in Figure 5, the frame 1 of the high-voltage transformer of the present invention is flat, and its purpose is to limit the number of turns of the high-voltage side winding 2 that can be wound in a single layer on the frame 1, thereby limiting the number of adjacent layers of the high-voltage side winding 2. The maximum voltage difference between them, thus solving the interlayer insulation problem of the high voltage side winding. In order to limit the maximum voltage difference between adjacent layers, the present invention specifies the maximum height H and the minimum width W of the window of frame 1 .

Assuming that the total number of turns of the high-voltage side winding required by the high-voltage transformer is N, the maximum voltage at both ends of the high-voltage side winding is V _max , the maximum withstand voltage value of the wire used to wind the high-voltage side winding 2 is V _lim , and the diameter of the wire is is D, then the voltage borne by each turn in the high-voltage side winding is:

$\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{\mathrm{<span\; class="notranslate">\; N</span>}}$

The maximum number of turns that can be wound at the window height of the skeleton is:

$\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; N</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lim</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}$

Therefore, the maximum window height value is:

$\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; Dn</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; N</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lim</span>}}\mathrm{<span\; class="notranslate">\; D.</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}$

The minimum window width values are:

$\mathrm{<span\; class="notranslate">\; W</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; no</span>}}\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}\mathrm{<span\; class="notranslate">\; D.</span>}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; lim</span>}}}$

As shown in FIG. 5 , a wire inlet hole 11 is also opened on the frame 1 as the wire inlet hole for the high-voltage side winding.

The winding structure and winding frame structure of the high-voltage transformer provided by the invention not only solve the insulation problem of the high-voltage winding of the high-voltage large-turn-ratio transformer, but also solve the coupling problem between the high-voltage winding and the low-voltage winding, and are relatively simple in manufacturing.

Specific embodiments of the present invention have been described in detail above. However, it should be understood that the embodiments of the present invention are not limited to these examples, and the descriptions of these examples are only used to help understand the spirit of the present invention. Under the spirit disclosed by the present invention, various modifications made to the present invention shall be included within the scope of the present invention. The scope of patent protection of the present invention should be defined by the appended claims.

Claims (4)

1, a kind of high-tension transformer comprises: magnetic core, skeleton and high-pressure side winding and low-pressure side winding, it is characterized in that described skeleton is flat, and described high-pressure side winding technique is on described skeleton, and the maximum height of the window of described skeleton (H) is $H=\mathrm{Dn}=\frac{N{V}_{\lim }D}{2V_{\max }},$ The minimum widith of window (W) is $W=\frac{N}{n}D=\frac{2V_{\max }D}{V_{\lim }};$ In the formula, N represents the total number of turns of described high-pressure side winding, V _LimBe the maximum withstand voltage of the lead of described high-pressure side winding, D represents the line footpath of the lead of described high-pressure side winding, V _MaxThe maximum voltage of representing winding two ends, described high-pressure side, n be the high Your Majesty of the window of described skeleton can around maximum numbers of turn.

2, high-tension transformer as claimed in claim 1 is characterized in that, described low-pressure side winding comprises printed circuit board (PCB) and is engraved on several circle Copper Foils on the described printed circuit board (PCB), near the described skeleton of the described high-pressure side of coiling winding.

3, high-tension transformer as claimed in claim 2 is characterized in that, described printed circuit board (PCB) is a double-sided printed-circuit board, all is carved with several circle Copper Foils on its two sides.

4, high-tension transformer as claimed in claim 1 is characterized in that, described low-pressure side winding is the flat type Copper Foil winding of pie, near the described skeleton of the described high-pressure side of coiling winding.

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