Patent Application
20130076473
1. Field of the Invention
The instant disclosure relates to a transformer; more particularly, to a transformer having increased creepage distance between the primary side and the secondary side thereof for meeting enhanced safety compliance.
2. Description of the Related Art
Transformers play an important role in electrical circuits. Different safety standards are imposed on different transformers depending on specific application. In particular, various countries have adopted standards mandating minimum creepage distance between the primary and second sides thereof The creepage distance is defined as the shortest distance on the surface of an insulating material between two conductive components, such as the primary and secondary coils of a transformer. If the creepage distance is less than the required minimum value, a short circuit between the primary and second coils may occur.
The primary coil and the secondary coil are normally separated by a single barrier structure. The barrier should be thick enough to provide sufficient creepage distance to prevent short circuit. However, the increase in thickness means an increase for the overall height of the transformer. Such side effect is undesirable for miniaturization of the electronic devices.
To address the above issues, the inventors strive via industrial experience and academic research to present the instant disclosure, which can effectively improve the limitation described above.
The instant disclosure provides a transformer capable of increasing the creepage distance. The safety standards can be met without increasing the thickness of the barrier, making the transformer useful for miniaturized electronic devices.
The instant disclosure also provides a transformer suitable for automatic winding operation. Namely, the primary and seconding coils can be created in one step.
The transformer of the instant disclosure comprises a bobbin, a primary coil, a secondary coil, and a core assembly. The bobbin has a first side portion and a second side portion formed oppositely thereon. A plurality of first pins is disposed on the first side portion, and a plurality of second pins is disposed on the second side portion. The bobbin has a winding portion, which has at least one first winding groove and at least one second winding groove formed thereon. The first winding groove and the second winding groove are separated by a barrier. A notch is formed on the barrier. The primary coil is wrapped in the first winding groove and connected to the first pins. The secondary coil is wrapped in the second winding groove and connected to the second pins. The core assembly is arranged on the bobbin.
The transformer of the instant disclosure has the following advantage. The notched barrier increases the creepage distance without increasing the wall thickness.
In order to further appreciate the characteristics and technical contents of the instant disclosure, references are hereunder made to the detailed descriptions and appended drawings in connection with the instant disclosure. However, the appended drawings are merely shown for exemplary purposes, rather than being used to restrict the scope of the instant disclosure.
Please refer to
At least one first winding groove 17 and at least one second winding groove 18 are formed on the winding portion 11. The number of first winding grooves 17 and second winding grooves 18 is not restricted. For the instant embodiment, the winding portion 11 has one first winding groove 17 and a pair of second winding grooves 18 formed thereon. The second winding grooves 18 are formed above the first winding groove 17. The first winding groove 17 and the second winding grooves 18 are separated by a barrier 19, which can be rectangular-shaped or have any other shapes. As illustrated in
As shown in
The transformer can further include an insulating cover 5. Like the bobbin 1, the insulating cover 5 is formed of plastic or other insulators. The structural configuration of the insulating cover 5 is not restricted either. As shown in
The core assembly 4 can be arranged on the bobbin 1, as shown in
It can therefore be seen that the notch 191 formed on the barrier 19 increases the creepage distance. The safety standards are met without compromising the thickness of the barrier 19, making the transformer useful for miniaturization of the electronic products.
Moreover, the insulating cover can be easily fitted onto the bobbin 1, thereby removing the need of wrapping any insulating tape. In addition, a fully automatic winding machine can be used to wrap the primary coil 2 and the secondary coil 3 all in one step. The coil wrapping process can be expedited to save cost.
The descriptions illustrated supra set forth simply the preferred embodiment of the instant disclosure; however, the characteristics of the instant disclosure are by no means restricted thereto. All changes, alternations, or modifications conveniently considered by those skilled in the art are deemed to be encompassed within the scope of the instant disclosure delineated by the following claims
