Building controller with lateral side shielding
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Solution Overview
Problem
Building controllers, such as HVAC controllers, face performance degradation due to electromagnetic interference (EMI) from both internal and external sources, which existing technologies have not adequately addressed.
Innovation Solution
The implementation of conductive side shield elements between the printed circuit board and the metal backing of the display in HVAC controllers, which are electrically connected to the ground plane, helps reduce EMI by containing internal noise and blocking external interference, thereby enhancing the shielding effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If building controllers use electronic components to control building functions, then the controller can perform heating, ventilation, and air conditioning control, but the electronic components generate electromagnetic interference that degrades performance of nearby components
Solution Approach 1:
The patent segments the building controller into shielded and unshielded regions by positioning conductive side shield elements between the printed circuit board and display. This segmentation isolates EMI-generating electronic components (processor, memory) in a shielded region, preventing their harmful electromagnetic emissions from affecting unshielded components like the antenna, while maintaining full building control functionality.
Solution Approach 2:
The conductive side shield elements act as an intermediary barrier between the EMI-generating electronic components and other building controller components. These shields, electrically connected to the ground plane, mediate the electromagnetic environment by redirecting EMI toward ground, thereby protecting sensitive components without compromising the controller's operational capabilities.
2Adaptability or versatility
If building controllers include components susceptible to EMI (such as antennas), then wireless communication functionality is enabled, but external EMI from sources like cell phones and microwave ovens degrades the performance of these components
Solution Approach 1:
The patent applies local quality by providing differential shielding: the antenna is positioned in an unshielded region to maintain wireless communication functionality, while electronic components are placed in shielded regions. The conductive side shield elements create localized EMI protection where needed, allowing the antenna to operate freely without degradation from external EMI sources while other components receive targeted protection.
3Reliability
If conductive side shield elements are added between the printed circuit board and display to reduce EMI, then electromagnetic shielding effectiveness is improved, but device complexity increases
Solution Approach 1:
The patent employs thin conductive side shield elements positioned between the printed circuit board and display, which are relatively simple in structure compared to enclosing the entire controller in shielding material. These thin shield elements provide effective EMI protection for electronic components while maintaining a compact design and avoiding excessive structural complexity, thus improving reliability without significantly increasing device complexity.
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 reduces EMI generated by internal components from escaping laterally and minimizes external EMI from entering, thereby improving the performance and reliability of the HVAC controller's components, including antennas.
Implementation Method 1
one or more conductive side shield elements are positioned between the printed circuit board and the display and extend along at least part of at least two lateral sides of the shielded region of the printed circuit board. The one or more conductive side shield elements may be electrically connected to the ground plane of the printed circuit board and may provide a side shield that reduces at least some EMI generated by the one or more electrical components
Data Source
AI summary
A thermostat includes a display having a metal backing, a printed circuit board having a ground plane, and one or more electrical components mounted to the printed circuit board in a shielded region on the printed circuit board between the ground plane and the metal backing. One or more conductive side shield elements are positioned between the printed circuit board and the display, extending along and defining the shielded region of the printed circuit board. The one or more conductive side shield elements are electrically connected to the ground plane of the printed circuit board and provide a side shield that reduces Electro-Magnetic Interference (EMI) generated by the one or more electrical components situated in the shielded region of the printed circuit board from escaping laterally out from between the ground plane of the printed circuit board and the metal backing of the display.