Optically Switchable Window Calibration with Electrical Feedback
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Solution Overview
Problem
Existing electrochromic devices face challenges in efficiently transitioning between optical states due to varying device sizes and operating conditions, requiring improved methods for controlling optical transitions and ensuring uniformity and safety.
Innovation Solution
The method involves using electrical feedback during transitions to adjust voltage and current, ensuring safe operating conditions and uniform tint levels across multiple devices, by applying voltage or current to bus bars, determining electrical characteristics, and adjusting parameters based on feedback to achieve targeted tint states and rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If fixed voltage or current is applied to drive optical transition, then the control method is simple, but the transition may be unsafe or non-uniform for devices of different sizes and conditions
Solution Approach 1:
The patent implements feedback control by measuring the actual electrical characteristics (current, voltage, resistance) during the optical transition process and using these measurements to dynamically adjust the drive parameters. This ensures that devices of different sizes and conditions receive appropriate drive signals, preventing unsafe conditions while maintaining uniform transition across all devices.
Solution Approach 2:
The control method transitions from static fixed voltage/current application to dynamic adjustment based on real-time device state. The system continuously monitors electrical characteristics and adapts the drive parameters during the transition process, allowing the control strategy to evolve with the device state rather than remaining fixed.
2Productivity
If higher current or voltage is applied to achieve faster transition, then the productivity increases, but the risk of device damage increases
Solution Approach 1:
The system uses real-time feedback from electrical characteristic measurements to dynamically adjust drive current and voltage levels. By monitoring actual device response during transition, the control algorithm can increase drive power when safe to accelerate transition, while automatically reducing power when approaching unsafe thresholds, thus optimizing both speed and safety.
Solution Approach 2:
The patent changes the drive parameters (current, voltage, power) dynamically during the transition process based on measured electrical characteristics. Rather than applying a fixed high power level, the system adjusts parameters in real-time to achieve maximum safe transition speed, allowing faster transitions when device conditions permit while preventing damage when conditions are marginal.
3Manufacturing precision
If individual calibration is performed for each device, then the manufacturing precision improves, but the device complexity and calibration time increase
Solution Approach 1:
The calibration process uses feedback from measured electrical characteristics to determine device-specific parameters. By measuring current, voltage, and resistance during transition and comparing against expected values, the system automatically calibrates each device's drive parameters without requiring complex manual procedures, achieving high precision while keeping the process relatively simple.
Solution Approach 2:
The calibration process is largely self-performing, using the device's own electrical characteristics during normal operation to determine its optimal drive parameters. The system automatically measures and extracts calibration information from the device's response to standard test signals, eliminating the need for external calibration equipment or complex manual procedures.
4Measurement precision
If electrical characteristics are continuously monitored during transition, then the control precision improves, but the device complexity and energy consumption increase
Solution Approach 1:
The system implements feedback control using measurements of electrical characteristics (current, voltage, resistance) taken during the transition process. These measurements provide precise information about the device state, enabling accurate control adjustments. The feedback loop is designed to be relatively simple, using standard electrical measurements rather than complex sensing systems.
Solution Approach 2:
The electrical characteristic measurements serve multiple functions: they provide feedback for control precision, enable calibration of device parameters, detect unsafe conditions, and optimize transition timing. By using the same measurement system for multiple purposes, the patent achieves high control precision without proportionally increasing system 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 approach ensures safe and uniform optical transitions across electrochromic devices, reducing the risk of damage and achieving consistent tint levels and rates, even in varying conditions.
Implementation Method 1
at least one layer of electrochromic material, that changes its optical properties in response to the application of an electrical potential
Implementation Method 2
an ion conductor (IC) layer that allows ions, such as lithium ions, to move through it, into and out from the electrochromic material
Data Source
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AI summary
The embodiments herein relate to methods for controlling an optical transition and the ending tint state of an optically switchable device, and optically switchable devices configured to perform such methods. In various embodiments, non-optical (e.g., electrical) feedback is used to help control an optical transition. The feedback may be used for a number of different purposes. In many implementations, the feedback is used to control an ongoing optical transition. In some embodiments a transfer function is used calibrate optical drive parameters to control the tinting state of optically switching devices.