JPH0566939U - Bobbin for transformer - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a transformer bobbin in which the lead wire 3a of the inner winding 3 does not approach the high-voltage outer winding 5 to cause dielectric breakdown. [Structure] A transformer having a base portion 10 in which a terminal 2 is implanted and a winding shaft protruding upward from the base portion 10, and a slit 12 for drawing out a lead wire of an inner winding is provided on a side surface of the base portion 10. In the use bobbin, downward protruding portions 12a are formed on the lower surface of the base portion 10 on both sides of the slit 12 near the winding axis. [Effect] When the winding is applied, the lead wire 3a of the inner winding 3
Is pressed by the protrusion 12a so as not to come too close to the outer winding 5, and the lead wire 3a of the inner winding 3 and the outer winding 5 are
A sufficient creepage distance can be secured between and.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a structure of a transformer bobbin suitable for a high frequency boosting transformer having a high voltage outer winding.

[0002]

[Prior Art]

 FIG. 1 is a front sectional view showing a configuration example of a bobbin 1 in a conventional step-up transformer, showing a wound state. The bobbin 1 is provided with a base portion 10 in which terminals 2 are planted on two opposite side surfaces, and a winding shaft 20 projecting upward from the center of the base portion 10, and a collar 22 is provided at the upper end of the winding shaft 20. It is provided. Slits 12 reaching the vicinity of the winding shaft 20 and slits 13 shallower than the slits 12 are provided on the two side surfaces of the base portion 10 on which the terminals 2 are implanted. As shown in FIG. 2, a large number of lead wires 3a of the inner winding 3 on the low voltage side wound around the winding shaft 20 are drawn out through one slit 12 and are respectively connected to predetermined terminals 2.

An outer winding 5 having a high voltage is wound on the outer side of the inner winding 3 via an insulating ring 4, and its lead wire 5 a is drawn out through the other slit 13 and connected to the terminal 2, respectively. Has been done. The inner winding 3 has a large number of lead wires 3a because taps are provided or the feedback winding is wound together, and since the total number of windings is small, many lead wires 3a have deeper slits. It will be led out in a concentrated manner from the tip near the 12 winding shafts 20. A protrusion 14 is provided on the lower surface of the base 10 near the root of the terminal 2.

[0004]

[Problems to be solved by the device]

 When the lead wire 3a of the inner winding 3 is connected to the terminal 2, the lead wire 3a may slide in the slit 12 and be pulled out to the outer winding 5 side. Since the outer winding 5 is exposed in the slit 12 in the immediate vicinity of the inner winding 3, the biased low-voltage lead wire 3a passes near the high-voltage outer winding 5. . As a result, electric discharge may occur between the lead wire 3a of the inner winding 3 having a large potential difference and the outer winding 5 to cause insulation breakdown.

[0005]

[The purpose of the device]

 An object of the present invention is to provide a bobbin for a transformer in which the lead wire of the inner winding 3 does not approach the high-voltage outer winding 5 and causes dielectric breakdown.

[0006]

[Means for Solving the Problems]

 The present invention relates to a transformer bobbin having a winding shaft protruding upward from the base portion and having a slit for pulling out the lead wire of the inner winding on the side surface of the base portion, a slit slightly separated from the tip of the slit. It is characterized in that downward projections are formed on the lower surfaces of the base portions on both sides.

[0007]

【Example】

 3 is a partial bottom view showing an embodiment of a transformer bobbin according to the present invention, FIG. 4 is a sectional view taken along the line AA, and FIG. 5 is a partial bottom view after winding. In these figures, the same parts as the conventional ones are designated by the same reference numerals as those in FIGS. 1 and 2. The bobbin of the present invention is different from the conventional bobbin in that the lower surface of the base portion 10 on both sides of the slit 12 is located slightly apart from the tip of the slit 12 for pulling out the lead wire 3a of the inner winding. The point is that the portion 12a is formed.

When the winding is applied to this bobbin, the lead wire 3a of the inner winding 3 drawn out to the lower surface of the bobbin through the tip of the slit 12 is drawn out through the outside of the two protrusions 12a, as shown in FIG. To do so. Even if these lead wires 3a are strongly pulled when they are led out in the direction of the respective terminals 2, the root portions are pressed by the protrusions 12a, so that they do not enter the portion of the slit 12 close to the outer winding 5. , A sufficient creepage distance is secured between the outer winding 5 and the outer winding 5. The protruding portion 12a may be formed by extending to the vicinity of the root of the terminal 2 as shown in FIG.

[0009]

[Effect of the device]

 Since the bobbin of the present invention is pressed by the protruding portion 12a so that the lead wire 3a does not approach the outer winding 5 when the winding is applied, the bobbin of the inner winding 3 and the outer winding 5 are A sufficient creepage distance is secured between the two, which has the effect of preventing the occurrence of dielectric breakdown.

[Brief description of drawings]

FIG. 1 is a front sectional view showing a conventional example of a trans bobbin having a winding.

FIG. 2 is a bottom view of a part of the trans bobbin.

FIG. 3 is a partial bottom view showing an embodiment of the bobbin of the present invention.

FIG. 4 is a sectional view taken along line AA of FIG.

FIG. 5 is a partial bottom view of the bobbin of the present invention with windings

FIG. 6 is a partial bottom view showing another embodiment of the bobbin of the present invention.

[Explanation of symbols]

 10 Base part 12 Slit 12a Projection part 20 Winding shaft

Claims (2)

[Scope of utility model registration request] 1. An inner winding lead wire is provided on a side surface of a base portion on a side on which a terminal is planted, the base portion having a terminal planted on an end portion, and a winding shaft projecting upward from the base portion. In the bobbin for the transformer with the slit for pulling out,
A bobbin for a transformer, characterized in that downward projecting portions are formed on the lower surfaces of the base portions on both sides of the slit, which are slightly apart from the tip of the slit. 2. The bobbin for a transformer according to claim 1, wherein the protrusion is formed so as to extend near the base of the terminal.