Condenser Microphone Shielding for Electromagnetic Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Condenser microphones connected via a dedicated microphone cord are prone to noise generation due to strong electromagnetic waves from cellular phones, as the shield covering line allows electromagnetic interference to enter the support enclosure.
Innovation Solution
A condenser microphone design featuring a two-core shield covering line with a shield covering line exposure portion where the shield covering line is stripped off, and an annular fixing member is used to connect the shield covering line to the support enclosure, preventing electromagnetic waves from entering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the shield covering line is pulled into the support enclosure together with the power line and signal line, then the microphone cord structure is simplified, but electromagnetic waves intrude into the support enclosure and are detected by the FET, generating noise
Solution Approach 1:
The shield covering line is segmented from the power line and signal line at the cord introduction hole. The shield covering line is stripped off to form a separate exposure portion, allowing it to be connected to the support enclosure independently while the power and signal lines continue into the enclosure. This segmentation prevents electromagnetic waves from traveling along the shield covering line into the enclosure while maintaining the simplified cord structure.
Solution Approach 2:
The annular fixing member acts as an intermediary component between the shield covering line exposure portion and the support enclosure. It provides a dedicated connection path for the shield covering line to the enclosure, serving as a mediator that redirects electromagnetic interference away from the sensitive FET while maintaining electrical continuity for shielding purposes.
2Object-affected harmful factors
If the shield covering line is stripped off to prevent electromagnetic wave intrusion, then noise generation is reduced, but the manufacturing process becomes more complex
Solution Approach 1:
The shield covering line is stripped off in advance to create the shield covering line exposure portion before final assembly. This preliminary action prepares the cord for the subsequent connection to the support enclosure, making the assembly process more straightforward by pre-positioning the shield connection point rather than requiring complex in-situ modifications.
Solution Approach 2:
The annular fixing member provides a standardized, repeatable connection structure that can be mass-produced and assembled efficiently. By using a pre-formed annular component rather than custom-fitted solutions, the manufacturing process benefits from standardized parts that simplify assembly while achieving the noise reduction goal.
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 configuration effectively prevents noise generation by ensuring high-frequency currents from electromagnetic waves flow to the support enclosure, reducing electromagnetic interference.
Implementation Method 1
a two-core shield covering line which includes power line for supplying power to the microphone capsule 10, a signal line for sending an audio signal generated from the FET 22 to the output module section, not shown, and a shield covering line for electrostatically shielding and grounding the power line and signal line
Implementation Method 2
the inner periphery side of the fixing member being fixed to the shield covering line exposure portion, and the outer periphery side thereof being connected electrically to the internal surface of the support enclosure
Data Source
AI summary
In a condenser microphone unit connected to an output module section via a dedicated microphone cord, the generation of noise caused by strong electromagnetic waves sent from a cellular phone etc. is effectively prevented by a simple configuration. In the condenser microphone unit in which a microphone capsule 10 is supported, for example, exchangeably on a support enclosure 20 and a microphone cord 30 consisting of a two-core shield covering line for connecting the condenser microphone unit to the output module section is pulled into the support enclosure 20, a shield covering line exposure portion 33a, in which a shield covering line 33 is stripped off, is provided in a portion in which the microphone cord 30 is pulled into the support enclosure 20, and a fixing member 40 formed into a doughnut shape is fixed to the shield covering line exposure portion 33a by staking, by which the shield covering line 33 is connected to the support enclosure 20 via the fixing member 40.