LED Lighting Device Discontinuous Boost Converter Bulk Reduction
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Solution Overview
Problem
Existing lighting solutions for liquid crystal matrix imagers in aeronautics require high dynamic range and luminance, small footprint, and synchronization with video scans, but are hindered by bulkiness due to the need for multiple step-up circuits and high-capacity capacitors.
Innovation Solution
A lighting device using a discontinuous conduction boost converter with individualized control for each mode and a servo device with multiple operating modes, including a digital or analog PWM control, to generate high voltage efficiently without large capacitors, allowing for precise control of duty cycles and simultaneous control of multiple ramps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If multiple step-up circuits are used to drive each ramp of diodes, then the luminance level and dynamic range are sufficient, but the device becomes excessively bulky
Solution Approach 1:
The patent merges multiple step-up circuits into a single high-voltage boost converter that supplies all diode ramps simultaneously. This consolidation reduces the number of separate power supply units from N (one per ramp) to just one, dramatically reducing device bulk while maintaining the ability to drive hundreds of diodes at the required luminance level.
Solution Approach 2:
The single high-voltage boost converter is designed to universally supply power to multiple diode ramps through parallel connection. This multi-functional power supply can dynamically adjust voltage distribution across different ramps, enabling one circuit to perform the function previously requiring multiple dedicated circuits.
2Reliability
If high-capacity electrochemical capacitors are used for power supply, then energy storage and stability are improved, but the device footprint increases
Solution Approach 1:
The patent extracts and eliminates the need for large high-capacity electrochemical capacitors by redesigning the power supply architecture. Instead of relying on bulk capacitors for energy storage and stability, the system uses a single high-voltage boost converter with optimized inductors and a novel capacitor connection scheme that provides necessary stability without the volume penalty.
Solution Approach 2:
The patent changes the operating parameters of the power supply system by using a single high-voltage source with dynamic voltage control rather than multiple low-voltage sources with large capacitors. This parameter change allows the system to achieve the same power delivery capability with significantly reduced component sizes.
3Stability of the object's composition
If current sources with independent control are used for each ramp, then current balance is improved, but power loss increases due to nominal voltage requirements
Solution Approach 1:
The patent merges multiple independently controlled current sources into a single high-voltage boost converter that supplies all ramps in parallel. This consolidation eliminates the redundant voltage generation required by separate current sources, reducing power loss while maintaining current balance through centralized control that adjusts individual ramp currents based on diode forward voltage variations.
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 reduces bulk and power consumption while maintaining high luminance and dynamic range, enabling efficient operation in low-light conditions and minimizing voltage ripple, thus suitable for compact, high-performance applications like helmet sights.
Implementation Method 1
A lighting device uses a discontinuous conduction boost converter with individualized control for each mode and a servo device with multiple operating modes, including a digital or analog PWM control, to generate high voltage efficiently
Implementation Method 2
Lighting device with LED and regulated power supply The field of the invention is that of lighting with light-emitting diodes used to illuminate liquid crystal matrix imagers
Data Source
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AI summary
The general field of the invention is that of lighting devices with light-emitting diodes (LEDs) arranged in parallel strips (Ri), each strip comprising a certain number of LEDs arranged in series, said strips being powered by a high-voltage direct current (HVDC) of several tens of volts, said voltage being generated by a boost converter circuit (BCC) from a low-voltage direct current of a few volts, the value of said voltage being controlled by the duty cycle of the boost converter circuit, said voltage being regulated to a constant average value by means of a control device (CD) controlling said duty cycle. Each control device has several operating modes, a mode being defined either by a specific electronic addressing of the high voltage or by a defined number of illuminated LED strips.To optimize the overall operation of the lighting system, the boost converter circuit is discontinuous conduction and the control system includes several electronic control circuits connected to an electronic multiplexer (MUX), each electronic control circuit being dedicated to a particular operating mode, the electronic characteristics of said electronic control circuits depending on said operating mode, said electronic control circuit being operational only when the operating mode is selected.