LED Light Bulb Controller with Photodetector Feedback
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Solution Overview
Problem
The variability in LED performance due to manufacturing differences and temperature sensitivity complicates the production of uniform LED-based lighting, requiring extensive testing and calibration, and necessitates stockholding different LED/phosphor sources for varying color temperatures, leading to increased costs and complexity for luminaire manufacturers and end-users.
Innovation Solution
An LED-based lighting device with a heat sink and interchangeable globes, featuring a controller that maintains a standard light intensity by adjusting the average current and using half-wave rectifiers, along with a photodetector to compensate for variations, allowing for standardized output and easy color temperature adjustments without replacing the LED.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If LED performance variability due to manufacturing differences and temperature sensitivity is addressed through extensive testing and calibration, then light output uniformity is improved, but production complexity and capital investment increase
Solution Approach 1:
The patent implements feedback control by incorporating photodetectors that continuously monitor the light output from each LED module and feed this information back to control circuits. The control circuits adjust the drive current to each LED module based on the photodetector readings, automatically compensating for manufacturing variations and temperature effects without requiring manual calibration during production.
Solution Approach 2:
The system performs self-calibration by using integrated photodetectors to automatically measure and characterize each LED module's output when first powered on. The control circuit stores these measurements and uses them to automatically adjust operating parameters, eliminating the need for external calibration equipment and manual adjustment during manufacturing.
2Adaptability or versatility
If different LED/phosphor sources are stocked for varying color temperatures, then color temperature adaptability is improved, but inventory complexity and cost increase
Solution Approach 1:
The patent designs a universal LED lighting system where a single LED module can produce multiple color temperatures by using controllable phosphor materials or multi-color LED chips. The control circuit can independently adjust the intensity of different wavelength LEDs (e.g., blue LED with yellow phosphor for warm white, blue LED with red phosphor for cool white), allowing one physical module to replace what would traditionally require multiple specialized modules.
Solution Approach 2:
The system changes the color temperature output by dynamically adjusting electrical parameters - specifically the relative drive currents to different LED chips or phosphor excitation levels - rather than requiring physical replacement of LED modules. This allows continuous adjustment of color temperature within a wide range from a single module.
3Manufacturing precision
If LED modules are designed with integrated phosphor for color temperature control, then color temperature precision is improved, but repairability and flexibility worsen
Solution Approach 1:
The patent segments the lighting system into independent, standardized LED modules that can be individually replaced. Each module contains its own control circuitry and phosphor materials, but the modular design with standardized connectors (such as bayonet or threaded interfaces) allows failed modules to be quickly swapped out without affecting other modules, significantly improving repairability compared to integrated designs.
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 solution ensures reproducible and uniform light output across devices, reduces capital investment, and allows for easy color temperature changes by swapping globes, thereby simplifying production and user maintenance.
Implementation Method 1
along with a photodetector to compensate for variations
Implementation Method 2
using half-wave rectifiers
Implementation Method 3
An LED-based lighting device with a heat sink
Data Source
AI summary
An LED-based lighting device and method for making the same are disclosed. The lighting device includes an LED light source mounted on a heat sink, a power adaptor, and a controller. The power adaptor is configured to be interchangeable with a conventional incandescent bulb power adapter. The controller provides an average current to the LED light source when power is coupled to the device via the power adaptor. The average current causes the LED light source to generate light of a predetermined standard intensity that is substantially independent of variations in the LED light source from device to device. In one aspect of the invention, the LED light source includes a plurality of LEDs connected in series, the LEDs are bonded to the heat sink and connected to one another in series by wire bonds and to conducting traces on the heat sink.