Lighting System Dual Power Supply Brightness Control
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Solution Overview
Problem
Existing lighting systems face challenges in maintaining precise brightness control across different lamp types, leading to errors in output current that fail to comply with regulatory brightness limits, particularly for low-brightness applications.
Innovation Solution
A lighting system comprising a light emitting unit, first and second power adjustment circuits, switches, and a switch control circuit that selectively switches between two power signals to control the driving current, using either a linear current source circuit or a switch power conversion circuit to achieve stable brightness levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If PWM dimming method is used to adjust brightness, then brightness can be varied, but output current tolerance becomes excessive due to part differences in mass production
Solution Approach 1:
The patent divides the single power supply system into two separate power supplies: a first power supply (linear power supply) for low-brightness applications and a second power supply (switching power supply) for high-brightness applications. Each power supply is optimized for its specific brightness range, with dedicated current control circuits that ensure precise output current tolerance for each segment, thereby resolving the tolerance issue while maintaining brightness adaptability.
Solution Approach 2:
The system changes the operating parameters by selecting different power supply modes based on brightness requirements. The control circuit switches between linear mode (for precise low-brightness control) and switching mode (for high-brightness operation), thereby optimizing both current tolerance and brightness adaptability across different operating conditions.
2Power
If switching power supply is used for large wattage lamps, then high power capability is achieved, but brightness control precision deteriorates
Solution Approach 1:
The patent segments the power supply functionality by assigning the linear power supply to handle low-brightness precision control and the switching power supply to handle high-brightness high-power applications. This segmentation allows each power supply type to operate in its optimal performance range, maintaining both power capability and brightness control precision.
Solution Approach 2:
The control circuit acts as an intermediary that intelligently selects which power supply to use based on the required brightness level. This mediator ensures that the appropriate power supply mode is activated, preventing brightness control precision deterioration while maintaining high power capability when needed.
3Measurement precision
If linear power supply is used for small wattage lamps, then precise brightness control is achieved, but power capability is limited
Solution Approach 1:
The system segments the operating ranges by using the linear power supply exclusively for low-brightness precision applications where its superior current control precision is needed, while directing high-power demands to the switching power supply. This segmentation allows linear power supplies to maintain their precision advantage without being constrained by power capability limitations.
Solution Approach 2:
The dual power supply system creates a universal lighting control system that can handle both precision low-power applications and high-power applications through intelligent switching. The overall system gains multi-functionality, combining the precision advantages of linear power supplies with the high power capability of switching power supplies.
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 approach allows for precise control of the driving current to the light emitting unit, reducing errors and ensuring compliance with regulatory brightness requirements by selectively using either a lower or higher current based on the received power signals.
Implementation Method 1
the first power adjustment circuit is a linear current source circuit
Implementation Method 2
the second power adjustment circuit is a switch power conversion circuit
Implementation Method 3
a light emitting unit LED
Data Source
AI summary
A lighting system suitable for receiving two kinds of power signals includes a light emitting unit, a switch control circuit, first and second power adjustment circuits, and first and second switches. The switch control circuit is electrically connected to the light emitting unit, the first and second switches. When the light emitting unit and the switch control circuit receive a first power signal, the switch control circuit turns on the first switch and turns off the second switch, so that a first current drives the light emitting unit to emit. When the light emitting unit and the switch control circuit do not receive the first power signal and the second power adjustment circuit receives the second power signal, the switch control circuit turns off the first switch and turns on the second switch, so that a second current drives the light emitting unit to emit.