LED Driver with Boost and Bypass Modes for Adjustable Illumination
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Solution Overview
Problem
Conventional boost type voltage regulators are limited in their ability to adjust LED drive voltage, leading to overdriving and potential damage when the configuration of LEDs changes, such as when a subset is decoupled from a string, necessitating a more flexible and tolerant LED driver for various coupling configurations.
Innovation Solution
A LED illumination system that operates in both boost and bypass modes, utilizing a boost converter with a boost controller to generate a boosted drive voltage in boost mode and a regular drive voltage in bypass mode, allowing for adaptable LED drive currents and configurations through the use of bypass elements and current sinks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a boost type voltage regulator is used to drive LEDs, then the illumination level can be adjusted within a limited voltage range, but the regulator cannot adapt when the LED coupling configuration changes (e.g., when LEDs are decoupled from a string)
Solution Approach 1:
The patent implements a dynamic LED driver system that can switch between boost mode and bypass mode based on the LED coupling configuration. The driver dynamically adjusts its operation: in boost mode when all LEDs are coupled in series requiring higher voltage, and in bypass mode when some LEDs are decoupled requiring lower voltage. This dynamic adaptation resolves the contradiction by making the system flexible to different configurations without requiring multiple fixed regulators.
Solution Approach 2:
The LED driver is designed with multi-functionality to handle both boost operation and bypass operation within a single device. The same driver circuit can regulate voltage for full LED strings (boost mode) or for subsets of decoupled LEDs (bypass mode), making it universally applicable to different coupling configurations. This eliminates the need for separate regulators for different configurations, reducing overall system complexity while improving adaptability.
2Reliability
If the enhanced LED voltage is reduced when a subset of LEDs is decoupled, then the voltage matches the new configuration, but the voltage regulator fails to drive the LEDs because the enhanced LED voltage would overdrive and damage the LEDs
Solution Approach 1:
The LED driver incorporates feedback mechanisms that monitor the LED coupling configuration and automatically adjust the output voltage accordingly. When LEDs are decoupled, the feedback system detects the changed load conditions and reduces the enhanced LED voltage from boost mode levels to bypass mode levels, preventing overdriving and damage. This automated feedback control makes the system reliable and easy to operate without manual intervention.
Solution Approach 2:
The driver is designed with beforehand cushioning by implementing protective circuitry that prevents voltage spikes and overdriving conditions before they can damage the LEDs. The bypass mode inherently provides voltage cushioning by limiting the maximum voltage to safe levels for decoupled LED configurations, ensuring that even if configuration changes occur, the LEDs are protected from damage.
3Adaptability or versatility
If a single drive voltage with limited voltage variation is used, then the system is simple to implement, but it cannot provide desirable illumination levels when LED coupling configuration varies
Solution Approach 1:
The system implements parameter changes by switching between two distinct voltage regulation modes: boost mode for high voltage requirements (full LED strings) and bypass mode for lower voltage requirements (decoupled LED subsets). This parameter switching allows the system to adapt to different LED configurations and provide desirable illumination levels while maintaining energy efficiency by using the appropriate mode for each configuration rather than forcing a single voltage level.
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 efficient and safe operation of LEDs across different coupling configurations by providing adjustable drive voltages, preventing overdriving and allowing for distinct brightness levels and camera features based on operation modes.
Implementation Method 1
The boost converter is coupled to the plurality of LEDs, and configured to generate a drive voltage to drive the plurality of LEDs. In the boost mode, the boost controller is electrically coupled to control the boost converter to drive the LED string by a boosted drive voltage.
Implementation Method 2
Light emitting diodes (LEDs) are applied to provide a wide variety of illumination solutions
Implementation Method 3
The plurality of LEDs is coupled in series to form a LED string
Data Source
AI summary
This application discloses an electronic device (e.g., a camera) that a plurality of light sources and a light source driver. The light sources are configurable to a plurality of light source subsets to illuminate a field of view. At least two of the light source subsets include distinct light source members and are configured to illuminate different regions of the field of view. The light source driver is coupled to the plurality of light sources and configured to drive the plurality of light source subsets. In some embodiments, the electronic device includes or is coupled to a camera module configured to capture visual data of the field of view, and the plurality of light sources is configured to provide illumination for the camera module.