Variable Transmittance Window Energy Harvesting Control

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Solution Overview

Problem

Existing variable transmittance window systems in vehicles rely on continuous power supply, which can be unreliable, and lack efficient energy harvesting mechanisms to maintain optimal light control without constant electrical input.

Innovation Solution

A variable transmittance window system powered by energy harvesting devices, such as photovoltaic, thermoelectric, and piezoelectric devices, coupled with energy storage and advanced circuitry for maximizing power generation and controlling transmittance states, including a master control circuit for wireless override and monitoring power supply availability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If continuous power supply is used to control variable transmittance windows, then the window transmittance control is reliable, but the energy consumption is high and requires external power sources

Engineering Contradiction:
Improvewindow transmittance control reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The window system harvests energy from the vehicle's vibration, temperature gradients, and light to power itself, eliminating dependence on external power sources. The energy harvesting device converts environmental energy into electrical power to drive the electrochromic windows, enabling the system to be self-sufficient and reduce overall energy consumption from the vehicle's electrical system.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system changes the operating parameters by switching from continuous power supply to intermittent power harvesting. The electrochromic windows can maintain their transmittance state without continuous power, and the system adapts to available energy levels by adjusting window operation timing and duration.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If energy harvesting devices are added to the window system, then energy independence is improved, but the device complexity increases

Engineering Contradiction:
Improveenergy independenceVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The energy harvesting device serves multiple functions: it powers the window control circuitry, charges the energy storage device, and can directly power the electrochromic windows. This multi-functionality reduces the need for separate power management systems and integrates power generation seamlessly into the existing window structure.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the energy harvesting device, energy storage device, and window control circuitry into an integrated system. The control unit manages multiple functions including monitoring energy levels, controlling window transmittance, and managing power distribution, thereby reducing overall system complexity through functional integration.

Inventive Principle:
Principle #5Merging (Combining)

3Power

If multiple energy harvesting devices are used, then power generation is maximized, but the manufacturing cost and complexity increase

Engineering Contradiction:
Improvepower generation capacityVSAvoidmanufacturing simplicity
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

Different types of energy harvesting devices are placed in optimal locations within the window system based on local conditions. For example, photovoltaic elements are positioned where light exposure is maximum, thermoelectric elements are placed where temperature gradients are steepest, and piezoelectric elements are located in high-vibration areas, thereby maximizing power generation from each device type.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system can operate with partial energy harvesting capability and gradually add more harvesting devices as needed. The control unit manages power distribution to ensure reliable operation even when not all energy harvesting devices are fully utilized, allowing for phased manufacturing and deployment.

Inventive Principle:
Principle #16Partial or excessive action

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

Enables autonomous and efficient control of transmittance states in variable transmittance windows, ensuring optimal light management even when the vehicle is not operating, by harnessing various energy sources and storing energy for later use, thus maintaining passenger comfort and reducing energy consumption.

Implementation Method 1

Power for controlling the window is derived from an energy harvesting device that generates power by converting thermal gradients, motion/vibration, or light energy present near the window

Methodology Applied
Scientific EffectThermal gradient conversion: Seebeck Effect

Implementation Method 2

Power for controlling the window is derived from an energy harvesting device that generates power by converting thermal gradients, motion/vibration, or light energy present near the window

Methodology Applied
Scientific EffectVibration conversion: Piezoelectric Effect

Implementation Method 3

Power for controlling the window is derived from an energy harvesting device that generates power by converting thermal gradients, motion/vibration, or light energy present near the window

Methodology Applied
Scientific EffectLight energy conversion: Photovoltaic Effect

Data Source

PatentEP3052985B1Variable transmittance window system
Publication Date: 2019.07.24 GENTEX CORP
  • EP3052985B1 patent drawingFigure 1
  • EP3052985B1 patent drawingFigure 2
  • EP3052985B1 patent drawingFigure 3

AI summary

A variable transmittance window system is provided and includes at least one variable transmittance window. At least one energy harvesting device generates electrical power. A power supply circuitry maximizes the electrical power. At least one energy storage device is charged by the electrical power. A slave control circuitry controls a transmittance state of the at least one variable transmittance window, the slave control circuitry being powered by at least one of the power supply circuitry and the at least one energy storage device. A master control circuitry monitors the slave control circuitry, wherein the master control circuitry is operable to issue a wireless override signal to the slave control circuitry such that the slave control circuitry changes the transmittance state of the at least one variable transmittance window to an override transmittance state.