This invention proposes an new type of inductor core unit for an inductor in order to achieve a longer operating period of the inductor with low sound emission while tolerating temperature fluctuations. The patent is active in Germany and France. It has counterparts in the U.S., China, Korea and Taiwan.
This invention is related to a method for production of an inductor core unit for an inductor in order to achieve a longer operating period of the inductor with low sound emission while tolerating temperature fluctuations.
To achieve mechanical stabilization of the inductor core prior art proposes filling materials (usually organic adhesives or silicones) in the air gaps having values of the coefficient of thermal expansion which are five to ten times higher than that of the inductor core material. This causes cracking in the filling material of the gap of the inductor core unit or in the magnetizable material of the inductor core, consequently reducing mechanical stability and amplifying sound emissions from inductor core unit.
The invention proposes to use filling material ,whose value for the coefficient of thermal expansion lies in the range of ±70% of the value of the coefficient of thermal expansion of the magnetizable material of which the inductor core is made. The temperature fluctuations during operation then lead to a comparable temperature-dependent expansion behaviour of the inductor core, and of the filling material, such that no cracks or mechanical damage occur. Applications: The proposed inductor can be used as a resonance, step-controller or lamp inductor for electronic ballasts.
The patent discloses the fabrication of an inductor core unit. Currently for mechanical stabilization of inductor core a magnetizable filling material is introduced in air gap, which generates an audible sound due to high temperature and reduce stability of inductor core. Proposed inductors use filling material with a coefficient of thermal expansion in a range of ±70% of that of inductor core magnetizable material. Also, the filling material uses water hardened cement selected from group of inorganic binder such as silicate, hydroxide, sulfate and phosphate so that inductor core has high operating period and low sound emission. Applications: The technology may be implemented in inductors, coils or chokes. Companies: Any company that produces inductors could be interested.
This Patent is about producing high quality Transformers or chokes with an Ferrite core known as "E"-core or the like.
Normally some kind of plastic or epoxy glue is used to glue the two parts of that "E" core together. This has the problem that the thermal expansion coefficient of the glue is much higher than that of the ceramic ferrite material of the "E"-core. This leads to cracks and an inconsistent air gap of the part over the lifetime. Sometimes this is mitigated ba using a very soft glue, on the other hand this leads to an inconsistent air gap due to the elasticity of the glue.
The invention overcomes this by using a ceramic cement to glue the two "E"-core halfes together forming a very sturdy and long lasting part which has no crack issues over the lifetime.
As the independent claim is fairly broad, this is a good and valuable patent. This applies also to the US patent, as the claim of the US patent is even broader than the European one.
Thank you for your review, Buggi! :-)