Dual Boost LED Driver for Dropout Tolerance
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Solution Overview
Problem
Conventional LED power converters face inefficiencies and larger energy storage component sizing due to the need for a two-stage arrangement with a high intermediate voltage, which compromises efficiency and cost in small LED lamps like MR16.
Innovation Solution
Implementing a dual boost converter stage system where one stage operates during powered periods and the other during dropout periods, utilizing energy storage components to maintain LED power without flicker, thereby optimizing energy use and reducing component size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a two-stage arrangement with high intermediate voltage is used, then power factor is improved, but efficiency deteriorates
Solution Approach 1:
The patent applies dynamics by making the converter topology adjustable between two modes: a first mode with a first voltage converting stage for high power factor operation, and a second mode with a second voltage converting stage for high efficiency operation. The mode controller dynamically switches between these configurations based on operating conditions, allowing the system to optimize for either power factor or efficiency as needed.
2Quantity of substance
If intermediate voltage is increased, then energy storage capacitor size is reduced, but converter efficiency deteriorates
Solution Approach 1:
The system dynamically adjusts the voltage converting stage configuration based on operating conditions. During normal operation, the first stage maintains appropriate intermediate voltage for efficient LED driving. During dropout conditions, the second stage activates to maintain LED operation, allowing the first capacitor to be sized for dropout protection rather than continuous high-voltage operation.
Solution Approach 2:
The patent segments the voltage conversion function into two separate stages: a first voltage converting stage for normal operation and a second voltage converting stage for dropout conditions. This segmentation allows each stage to be optimized for its specific function, with the second stage acting as a backup that activates only when needed, thereby reducing the required size of energy storage components.
3Reliability
If two-stage arrangement is used, then dropout tolerance is improved, but device complexity increases
Solution Approach 1:
The mode controller dynamically switches between operational modes based on input power conditions. During normal operation, only the first voltage converting stage is active, simplifying the operational complexity. When dropout conditions are detected, the controller activates the second stage to maintain LED operation, providing dropout tolerance without requiring both stages to operate simultaneously in all conditions.
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 achieves high efficiency and dropout tolerance while minimizing the size and cost of energy storage components, making it suitable for small LED lamps.
Implementation Method 1
a first voltage converting stage (112) having an input terminal (112a) for receiving an input voltage VIN and an output terminal (112b), and being configured to increase the VIN to a first output voltage V1st at the output terminal (112b)
Implementation Method 2
a second voltage converting stage (118) having an input (118a) electrically connected to the charge storage device (116), the second voltage converting stage (118) being configured to increase the VC to at least VLED min
Data Source
AI summary
A driver for generating an output voltage to power an LED having a minimum operating voltage VLED min, comprising: (a) a first voltage converting stage comprising an input terminal and an output terminal; (b) a charge storage device electrically connected to the output terminal and having a charge output voltage VC; (c) at least one second voltage converting stage having an input electrically connected to the charge storage device, the second voltage converting stage being configured to increase said VC to at least VLED min; and (d) at least one mode controller to switch between at least a first mode and a second mode, in the first mode, the first voltage converting stage charges the charge storage device to power the LED without substantial contribution from the second voltage converting stage, and, in the second mode, the second voltage converting stage power to the LED.