LED Amplification Circuit with Thermal Housing for Voltage Adaptation
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Solution Overview
Problem
Current flashlights using LEDs face limitations in maintaining consistent brightness across varying battery voltages and require efficient heat management to extend LED lifespan, especially in applications needing high luminance like automotive repair, where existing Buck operation is inefficient and heat dissipation is inadequate.
Innovation Solution
A light emitting apparatus with a pulse width modulation controller, a resistor, and an amplification circuit for current regulation, coupled with a thermally conductive housing to maintain LED junction temperature, allowing operation across a wide range of voltages and currents while minimizing power loss and heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If Buck operation is used for LED driving, then power efficiency is improved, but output voltage exceeds certain battery voltage ranges
Solution Approach 1:
Instead of using a Buck converter that steps down voltage (which cannot handle low battery voltages), the patent employs a Boost converter that steps up voltage. This inverted approach allows the circuit to operate efficiently with low-voltage battery inputs while still providing sufficient voltage to drive the LED at required current levels, thereby resolving the voltage range compatibility issue while maintaining power efficiency.
Solution Approach 2:
The patent changes the operating parameters of the power conversion circuit from Buck mode to Boost mode, and adjusts the duty cycle dynamically based on battery voltage levels. This parameter adjustment allows the system to adapt to varying battery voltages (including low-voltage conditions) while maintaining efficient power conversion and consistent LED output, thus resolving both efficiency and adaptability concerns.
2Illumination intensity
If LED is driven at high current for high luminance, then brightness is improved, but heat generation increases
Solution Approach 1:
The patent incorporates a feedback mechanism that monitors LED forward voltage and adjusts the drive current accordingly. By measuring the actual voltage drop across the LED and using this information to regulate the current through the Boost converter, the system maintains optimal luminance while preventing excessive current that would generate harmful heat, thus resolving the contradiction between brightness and heat generation.
Solution Approach 2:
The patent introduces a sense resistor and voltage monitoring circuit as intermediaries between the power source and LED. These intermediaries measure the actual operating conditions and provide feedback to the control circuit, enabling precise regulation of LED current. This intermediary measurement system allows the circuit to achieve high luminance when needed while automatically reducing current to prevent excessive heat generation, resolving the brightness-heat contradiction.
3Illumination intensity
If series connection of multiple LEDs is used, then total luminance is improved, but total voltage drop increases
Solution Approach 1:
Instead of using a Buck converter that requires high input voltage (which cannot accommodate low battery voltages in series LED configurations), the patent employs a Boost converter that can generate the required high voltage from low battery inputs. This allows series connection of multiple LEDs (increasing total luminance) while being compatible with low-voltage battery sources, as the Boost converter steps up the voltage to match the series LED string requirements.
Solution Approach 2:
The patent designs a universal power conversion system that can accommodate various battery voltages and LED configurations. The Boost converter with adjustable duty cycle and feedback control can adapt to different numbers of series-connected LEDs, making the system versatile for achieving desired total luminance levels without being constrained by fixed voltage drops, thus resolving the luminance-voltage drop contradiction.
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
The solution enables consistent brightness and extended battery life by efficiently regulating current and heat management, achieving high luminance with reduced power loss and heat dissipation, thus enhancing the durability and flexibility of LED flashlights.
Implementation Method 1
An amplification circuit is electrically coupled to the resistor and the pulse width modulation controller for supplying a feedback voltage to the pulse width modulation controller, the feedback voltage being proportionally changed relative to a resistor voltage measured across the resistor, a current through the first resistor or a resistance of the first resistor
Implementation Method 2
A housing including a portion defining a thermally conductive outer surface. An internal heat sink thermally couples the light emitting diode and the thermally conductive outer surface portion of the housing
Implementation Method 3
a light emitting diode electrically coupled to the voltage source
Data Source
AI summary
A light emitting apparatus having a housing including a portion defining a thermally conductive outer surface, a light source positioned within the housing, and an internal heat sink thermally coupling the light source and the thermally conductive outer surface portion of the housing. The light source may be a solid state device, such as a light emitting diode.