Transformer

A transformer includes a bobbin, at least one primary winding coil, at least one secondary winding coil, and a magnetic core assembly. The bobbin includes a main body, plural extension structures, and plural pin groups. The main body includes a channel, plural winding sections, a first connecting seat, and a second connecting seat. The plural extension structures are connected with the first connecting seat and the second connecting seat, respectively. In addition, each of the plural extension structures has a notch and a stepped structure, and the stepped structure comprises plural stepped parts. Each of the primary winding coil and the secondary winding coil includes plural outlet terminals. The plural outlet terminals of the secondary winding coil are respectively disposed on the plural stepped parts of the stepped structure and fixed on the pin group which is disposed on one of the extension structures.

TECHNICAL FIELD

The present disclosure relates to a transformer, and more particularly to a transformer with an increased creepage distance between a magnetic core assembly and a secondary winding coil.

DESCRIPTION OF THE RELATED ART

Magnetic elements such as inductors and transformers are widely used in power supply apparatuses or many electronic devices to generate induced magnetic fluxes. A transformer is a device that transfers electric energy from one circuit to another through coils in order to regulate the voltage to a desired range required for powering the electronic device.

FIG. 1is a schematic exploded view of a conventional transformer. As shown inFIG. 1, the transformer1comprises a bobbin10, a primary winding coil11, a secondary winding coil12, and a magnetic core assembly13. The primary winding coil11and the secondary winding coil12are wound around the bobbin10. The outlet terminals110of the primary winding coil11and the outlet terminals120of the secondary winding coil12are wound around and fixed on pins101, which are extended from two opposed sides of the bobbin10. The magnetic core assembly13is combined with the bobbin10, and partially embedded into a channel102of the bobbin10. After the bobbin10and the magnetic core assembly13are combined together, the transformer1is assembled. Consequently, the transformer1may be electrically connected with a circuit board (not shown) through the pins101.

Moreover, after the outlet terminals110of the primary winding coil11are wound around and soldered on the pins101at a first side of the bobbin10, some drawbacks may occur. Since the gap between any two adjacent pins101at the first side of the bobbin10is very short, the region between two outlet terminals110of the primary winding coil11is possibly stained with solder paste. Under this circumstance, the transformer1is readily suffered from a short-circuited problem. Moreover, the creepage distance between the outlet terminals110of the primary winding coil11fixed on the pins101of the bobbin10, the creepage distance between the outlet terminals120of the secondary winding coil12fixed on the pins101of the bobbin10, the creepage distance between the outlet terminals110of the primary winding coil11and the magnetic core assembly13and the creepage distance between the outlet terminals120of the secondary winding coil12and the magnetic core assembly13are usually insufficient. Moreover, after the outlet terminals120of the secondary winding coil12are wound around and soldered on the pins101at a second side of the bobbin10, the exposed portions of the secondary winding coil12are usually sheathed by tubes14. The uses of the tubes14may protect the exposed portion of the secondary winding coil12from being cracked in response to the external force. Although the uses of the tubes14may protect the exposed portion of the secondary winding coil12, there are still some drawbacks. For example, the procedure of sheathing the tubes14is time-consuming and labor-intensive. In addition, the uses of the tubes14increase the fabricating cost.

As mentioned above, the outlet terminals110of the primary winding coil11and the outlet terminals120of the secondary winding coil12are respectively fixed on the pins101at the two opposed sides of the bobbin10of the conventional transformer1. Since the pins101are symmetrically arranged at the two opposed sides of the bobbin10, during the process of mounting the transformer1on a circuit board (not shown), the worker may erroneously insert the pins of the transformer1into unmatched conductive holes (not shown) of the circuit board. Under this circumstance, the circuit board fails to be normally operated or even the circuit board has a breakdown. In other words, the conventional transformer1has no foolproof mechanism for facilitate the worker to mount the transformer on the circuit board. Moreover, for fabricating the transformer1, the primary winding coil11and the secondary winding coil12are manually wound around the bobbin10and then the tubes14are sheathed around the secondary winding coil12. The process of fabricating the transformer1is labor-intensive and time-consuming, and the fabricating cost is high. Moreover, since the winding coils are readily broken, the process of fabricating the transformer1wastes much material.

Therefore, there is a need of providing an improved transformer in order to eliminate the above drawbacks.

BRIEF SUMMARY

The present disclosure provides a transformer. The bobbin of the transformer has plural extension structures. Each of the plural extension structures has a notch and a stepped structure. Consequently, the creepage distance between a magnetic core assembly and a secondary winding coil will be increased, and the overall volume of the transformer is reduced.

The present disclosure also provides a transformer whose bobbin has a stepped structure. The stepped structure comprises plural stepped parts. Due to the altitude difference between every two adjacent stepped parts, the region between every two adjacent stepped parts may be defined as a wire-managing part. The outlet terminals of the secondary winding coil may be supported on the plural stepped parts. Consequently, the creepage distance between the outlet terminals of the secondary winding coil will be increased to meet the electric safety regulations.

The present disclosure further provides a transformer with good electrical properties to avoid the arcing effect. Moreover, the transformer may be fabricated by an automatic winding method, and the transformer may have a foolproof positioning mechanism.

In accordance with an aspect of the present disclosure, there is provided a transformer. The transformer includes a bobbin, at least one primary winding coil, at least one secondary winding coil, and a magnetic core assembly. The bobbin includes a main body, plural extension structures, and plural pin groups. The main body includes a channel, plural winding sections, a first connecting seat, and a second connecting seat. The plural extension structures are connected with the first connecting seat and the second connecting seat, respectively. In addition, each of the plural extension structures has a notch and a stepped structure, and the stepped structure comprises plural stepped parts. The plural pin groups are disposed on the first connecting seat, the second connecting seat and the plural extension structures. The at least one primary winding coil and at least one secondary winding coil are wound around the plural winding sections. Each of the at least one primary winding coil and the at least one secondary winding coil includes plural outlet terminals. The magnetic core assembly is partially embedded within the channel of the main body. The plural outlet terminals of the secondary winding coil are respectively disposed on the plural stepped parts of the stepped structure and fixed on the pin group which is disposed on one of the extension structures.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 2Ais a schematic exploded view illustrating a transformer according to an embodiment of the present disclosure.FIG. 2Bis a schematic assembled view illustrating the transformer ofFIG. 2A. In this embodiment, the transformer of the present disclosure may be applied to a pulse transformer. As shown inFIG. 2, the transformer2comprises a bobbin20, at least one primary winding coil21, at least one secondary winding coil22, and a magnetic core assembly27. The at least one primary winding coil21and the at least one secondary winding coil22are wound around the bobbin20. The bobbin20comprises a main body23, plural extension structures24, and plural pin groups. The main body23comprises a channel230, plural winding sections233, a first connecting seat235, and a second connecting seat236. The channel230runs through the main body23. The at least one primary winding coil21and the at least one secondary winding coil22are wound around the plural winding sections233. The first connecting seat235and the second connecting seat236are located at two opposed sides of the main body23. The main body23further comprises plural partition plates231and two lateral plates232. The two lateral plates232are located at the two opposed sides of the main body23. The plural partition plates231are disposed on the main body23and arranged between the two lateral plates232at regular spacing intervals or irregular spacing intervals. In addition, the plural partition plates231are parallel with each other. Consequently, the plural winding sections233are defined by the plural partition plates231and the two lateral plates232collaboratively. In this embodiment, the plural winding sections233comprise plural first winding sections233aand plural second winding sections233b. The plural first winding sections233aare located at bilateral sides of the plural second winding sections233b. The at least one primary winding coil21is wound around the first winding sections233aof the bobbin20. The at least one secondary winding coil22is wound around the second winding sections233bof the bobbin20. In this embodiment, the bobbin20comprises two first winding sections233aand two second winding sections233b. It is noted that the numbers of the first winding sections233aand the second winding sections233bmay be varied according to the practical requirements.

In this embodiment, the plural extension structures24comprise a first extension structure240and a second extension structure241. The first extension structure240is connected with the first connecting seat235of the main body23. The second extension structure241is connected with the second connecting seat236of the main body23. In this embodiment, the first extension structure240and the second extension structure241are integrally extended from the first connecting seat235and the second connecting seat236of the main body23, respectively. In addition, the first extension structure240and the second extension structure241are parallel with each other, and extend from the same side of the first connecting seat235and the second connecting seat236. Take the first extension structure240for example. Along a direction distant from the main body23(e.g. along the direction A), at least one first notch2401and at least one first stepped structure2402are sequentially formed on the top surface of the first extension structure240. The first notch2401is defined by a flank of the first connecting seat235and a stopping plate2403of the first extension structure240collaboratively. The first stepped structure2402is formed on the top surface of the first extension structure240, and the first stepped structure2402comprises plural stepped parts whose altitudes are gradually decreased along the direction A. Please refer toFIGS. 2A and 2B. In this embodiment, the first stepped structure2402comprises a first stepped part2402aand a second stepped part2402b. (In other embodiments, the first stepped structure2402may comprise more stepped parts.) Moreover, the stopping plate2403is arranged between the first stepped part2402aof the stepped structure2402and the first notch2401. The altitude of the stopping plate2403is higher than the surface of the first stepped part2402a. Due to the altitude difference between the stopping plate2403and the first stepped part2402a, the region between the stopping plate2403and the first stepped part2402amay be defined as a first wire-managing part2404. Due to the altitude difference between the first stepped part2402aand the second stepped part2402b, the region between the first stepped part2402aand the second stepped part2402bmay be defined as a second wire-managing part2405. The first wire-managing part2404and the second wire-managing part2405are used for disposing different segments of the secondary winding coil22in order to manage the secondary winding coil22.

In this embodiment, the second extension structure241also comprises at least one second notch2411, at least one second stepped structure2412, and a stopping plate2413. Similarly, the second stepped structure2412also comprises a first stepped part2412aand a second stepped part2412b. Similarly, due to the altitude difference between the stopping plate2413and the first stepped part2412a, the region between the stopping plate2413and the first stepped part2412amay be defined as a first wire-managing part2414. Similarly, due to the altitude difference between the first stepped part2412aand the second stepped part2412b, the region between the first stepped part2412aand the second stepped part2412bmay be defined as a second wire-managing part2415. Similarly, the first wire-managing part2414and the second wire-managing part2415are used for disposing different segments of the secondary winding coil22in order to manage the secondary winding coil22.

Please refer toFIGS. 2A and 2Bagain. The plural pin groups of the bobbin20comprise plural first pin groups25and plural second pin groups26. The plural first pin groups25are disposed on the outer surfaces of the first connecting seat235and the second connecting seat236of the main body23. The outlet terminals of the primary winding coil21are wound around and fixed on the plural first pin groups25. The plural second pin groups26are disposed on the outer surfaces of the first extension structure240and the second extension structure241. The outlet terminals of the secondary winding coil22are wound around and fixed on the plural second pin groups26. In some embodiments, the plural pins of the first pin group25on the first connecting seat235and the plural pins of the first pin group25on the second connecting seat236are arranged in an asymmetric form or a staggered form. Alternatively, the number of the plural pins of the first pin group25on the first connecting seat235may be different from the number of the plural pins of the first pin group25on the second connecting seat236.FIG. 3is a schematic top view illustrating the transformer ofFIG. 2B. As shown inFIG. 3, the number of the plural pins of the first pin group25on the first connecting seat235is different from the number of the plural pins of the first pin group25on the second connecting seat236. Since the plural pins of the first pin group25are specially arranged, the plural pins of the first pin group25may provide a foolproof positioning function. When the transformer2is mounted on a circuit board (not shown), the possibility of erroneously inserting the pins into the unmatched conductive holes of the circuit board will be minimized. Moreover, each of the plural second pin groups26comprises plural pins261and262corresponding to the stepped parts2402aand2402b, respectively, or corresponding to the stepped parts2412aand2412b, respectively. In this embodiment, each of the plural second pin groups26comprises two pins. It is noted that the number of the pins of the second pin group26may be varied according to the practical requirements.

Please refer toFIGS. 2A and 2Bagain. The magnetic core assembly27comprises a first magnetic part270and a second magnetic part271. The first magnetic part270comprises a middle portion270aand two leg portions270b. The second magnetic part271also comprises a middle portion271aand two leg portions271b. In this embodiment, the first magnetic part270and the second magnetic part271are E cores, so that the magnetic core assembly27is an EE-type magnetic core assembly. In some embodiments, the first magnetic part270and the second magnetic part271of the magnetic core assembly27are collaboratively defined as a UI-type magnetic core assembly or an EI-type magnetic core assembly. Moreover, in this embodiment, the middle portion270aof the first magnetic part270and the middle portion271aof the second magnetic part271are embedded into the channel230of the main body23.

Please refer toFIGS. 2A and 2Bagain. The primary winding coil21has outlet terminals211and212, and the secondary winding coil22has outlet terminals221and222. A process of assembling the transformer2will be illustrated as follows. Firstly, the primary winding coil21and the secondary winding coil22are respectively wound around the first winding sections233aand the second winding sections233bof the bobbin21. Then, the outlet terminals211and212of the primary winding coil21are directed through corresponding guiding recesses at the bottom of the first connecting seat235of the main body23of the bobbin20. Then, the outlet terminals211and212of the primary winding coil21are respectively wound around and fixed on the pins251and252of the first pin group25, which are disposed on the first connecting seat235. The outlet terminals221and222of the secondary winding coil22come out from the bottom of the main body23. The outlet terminal221of the secondary winding coil22is directed through the first wire-managing part2404of the first extension structure240and fixed on the pin261of the second pin group26. The outlet terminal222of the of the secondary winding coil22is directed through the second wire-managing part2405of the first extension structure240and fixed on the pin262of the second pin group26. In this embodiment, the ways of winding, managing and fixing another primary winding coil21and another secondary winding coil22on the second connecting seat236and the second extension structure241of the bobbin20are similar to those of the primary winding coil21and the secondary winding coil22mentioned above, and are not redundantly described herein. After the primary winding coils21and the secondary winding coils22are fixed on the pin groups25and26, the middle portion270aof the first magnetic part270and the middle portion271aof the second magnetic part271are embedded into the channel230of the main body23, and the leg portions270band271bare located at bilateral sides of the main body23of the bobbin20. Meanwhile, the transformer2is assembled.

From the above description, the bobbin20of the transformer2of the present disclosure has plural extension structures24. The plural extension structures24comprise the notches2401,2411and the stepped structures2402,2412. So that when the volume of the bobbin20of the transformer2of the present disclosure is equal to the volume of the bobbin of the conventional transformer, the arrangement of the notches2401and2411can increase the creepage distance between the magnetic core assembly27and the secondary winding coil22. In other words, the overall volume of the transformer2of the present disclosure may be reduced with the proviso that the creepage distance of the transformer2meets the electric safety regulations. Moreover, due to the stepped parts2402a,2402b,2412aand2412bof the stepped structures2402and2412of the extension structures24of the bobbin20, it is not necessary to use the insulating tubes to separate the outlet terminals221and222of the secondary winding coil22from each other. Moreover, since the creepage distance between the outlet terminals221and222of the secondary winding coil22may be increased to meet the electric safety regulations, the possibility of generating the arching effect at the regions between the outlet terminals221and222of the secondary winding coil22and the pins261and262will be minimized. Moreover, since the first wire-managing parts2404,2414and the second wire-managing parts2405,2415may be used for storing the segments of the secondary winding coil22, the efficacy of protecting and managing the secondary winding coil22can be reached. Moreover, the transformer2of the present disclosure has good electrical properties and may be fabricated by an automatic winding method. Moreover, by adjusting the arrangements or the numbers of the plural pins of the first pin group25on the first connecting seat235and the plural pins of the first pin group25on the second connecting seat236, the transformer2may have a foolproof positioning mechanism.