Auto-sensing Switching Regulator for LED Current Regulation
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Solution Overview
Problem
Conventional linear current regulators for high-brightness LEDs suffer from inefficiency, leading to excess power dissipation as heat, requiring higher-rated and more expensive components, and increased operating costs due to ohmic losses.
Innovation Solution
An auto-sensing switching regulator is introduced between the voltage source and current regulator, dynamically adjusting the output voltage to approximate the forward voltage drop across the LED, reducing excess voltage dissipation and enhancing power transfer efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a linear current regulator is used to drive LED with constant voltage source, then constant current can be provided to LED, but excess power is dissipated as heat due to ohmic losses
Solution Approach 1:
The patent changes the operating parameters of the regulator by transitioning from linear regulation to switching regulation. The switching regulator operates the pass transistor in saturation and cutoff regions rather than active mode, fundamentally changing how voltage and current are controlled to minimize power dissipation while maintaining constant LED current
Solution Approach 2:
The patent replaces the linear regulator mechanism with a switching regulator mechanism. Instead of using continuous analog control with ohmic losses, the system uses pulse-width modulation and switching elements to regulate current, substituting the mechanical/electrical continuous control system with a digital-like switching system that dramatically reduces energy loss
2Power
If constant voltage source provides voltage higher than LED forward voltage plus overhead, then sufficient voltage headroom is available for regulation, but efficiency decreases due to excess voltage dissipation
Solution Approach 1:
The patent implements dynamic voltage adjustment through switching regulation. The output voltage is continuously adjusted in real-time based on feedback from the LED forward voltage sensing, allowing the system to adapt to changing conditions and minimize voltage differential, thereby reducing power dissipation while maintaining adequate headroom for regulation
Solution Approach 2:
The patent employs feedback control where the switching regulator monitors the actual voltage across the LED and adjusts its output accordingly. This closed-loop feedback mechanism ensures the regulator provides exactly the voltage needed plus minimal overhead, preventing excessive voltage dissipation while maintaining sufficient headroom for proper current regulation
3Ease of manufacture
If linear current regulator is used, then simple and inexpensive components can be used, but higher-rated and larger components are required to handle heat dissipation
Solution Approach 1:
The patent converts the harmful effect of high voltage differential into a benefit by using switching regulation. The high input voltage is efficiently converted to the required output voltage through switching and energy storage elements, transforming what would be wasted energy into useful output power, thereby eliminating the need for large heat-sinking components
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 auto-sensing switching regulator improves power transfer efficiency by minimizing voltage overhead, reducing conversion losses from 24.5% to 5.25%, resulting in a 78% improvement and lower operating costs.
Implementation Method 1
an auto-sensing switching regulator, coupled between a voltage source and a current regulator, to drive a light source
Implementation Method 2
The development of high-brightness solid state light sources, such as but not limited to light emitting diodes (LEDs)
Implementation Method 3
The controller is configured to provide a control signal to the switching regulator to increase the output voltage while receiving a current sense signal representative of a current output of the switching regulator
Data Source
AI summary
An auto-sensing switching regulator, and systems and methods including same, is disclosed. The auto-sensing switching regulator includes a switching regulator and a controller coupled thereto. The controller is configured to provide a control signal to the switching regulator to increase the output voltage while receiving a current sense signal representative of a current output of the switching regulator, and to provide the control signal in response to the current sense signal to set the output voltage at a set value corresponding to a value at which the current output stops increasing with an increase in the output voltage. A system to drive a light source includes a current regulator configured to provide a constant current output to the light source and an auto-sensing switching regulator coupled to the current regulator, and configured to receive an input voltage from a voltage supply and provide an output voltage to the current regulator.