Common Mode Choke Coil Asymmetric Winding for Current Capacity
Solution Overview
Problem
Conventional common mode choke coils face limitations in increasing the rated current value due to heat emission issues in the third coil, which is prone to overheating due to equal resistance values across all coils, restricting the overall current capacity.
Innovation Solution
The common mode choke coil design features a third winding with fewer turns than the first and second windings, reducing its resistance value and heat emission, allowing for a higher rated current capacity by optimizing the number of turns in the third winding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the third coil has the same number of turns as the first and second coils, then the magnetic fields cancel each other out effectively, but the third coil emits excessive heat and the rated current value is limited
Solution Approach 1:
The patent applies local quality by making the third winding have a different number of turns (fewer turns) compared to the first and second windings. This creates a local difference in resistance values, allowing the third winding to have lower resistance and thus emit less heat, while the other windings maintain their original turn counts to preserve magnetic field cancellation and DC superposition characteristics.
2Reliability
If the third coil has the same resistance as the first and second coils, then the magnetic field cancellation is effective, but the rated current value cannot be increased due to heat emission constraints
Solution Approach 1:
The patent creates local quality differentiation by setting the third winding's turn count differently from the first and second windings. This results in the third winding having lower resistance specifically, which reduces its heat emission and allows higher current flow, thereby increasing the overall rated current value while the other windings maintain their original characteristics for effective magnetic field cancellation.
3Device complexity
If equal number of turns are used in all coils, then the structure is simple and symmetric, but the third coil becomes a bottleneck for current increase due to heat emission
Solution Approach 1:
The patent applies asymmetry by making the third winding have a different number of turns compared to the first and second windings. This asymmetric configuration creates a local difference in resistance values, allowing the third winding to have lower resistance and reduced heat emission, thereby eliminating the current bottleneck while maintaining overall structural simplicity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design effectively increases the rated current value by suppressing heat emission in the third winding, enabling higher current flow through the first and second windings while maintaining superior DC superposition characteristics.
Implementation Method 1
the orientation of a magnetic field generated by the first coil 112 and the orientation of a magnetic field generated by the second coil 114 are opposite to the orientation of a magnetic field generated by the third coil 116. In other words, the magnetic fields generated by the first coil 112 and the second coil 114 and the magnetic field generated by the third coil 116 cancel each other out.
Implementation Method 2
A number of turns in the third winding is less than a number of turns in the first winding and a number of turns in the second winding... reducing its resistance value and heat emission
Data Source
AI summary
A common mode choke coil includes a core and a first winding, a second winding, and a third winding that are wrapped around the core. A number of turns in the third winding is less than a number of turns in the first winding and a number of turns in the second winding.