AC LED Current Controller Regulates Operating Voltage
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Solution Overview
Problem
AC LED lighting systems face challenges in power efficiency and power factor due to the high power consumption of low dropout linear regulators (LDOs) and voltage drop, which affects the overall performance and lifespan of the lighting systems.
Innovation Solution
The AC LED lighting system employs a current controller with LED drivers that regulate the operating voltage using error amplifiers and LDOs to minimize power consumption by charging capacitors only during startup or when the voltage is low, and utilizes a full-wave rectifier to manage LED groups efficiently, allowing LDOs to work more efficiently by reducing the voltage difference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a low dropout linear regulator (LDO) is used to provide operating voltage, then the voltage can be regulated, but the power consumption increases significantly due to high voltage drop
Solution Approach 1:
The patent extracts the LDO from the high-voltage path by introducing a switching mechanism that connects the LDO only when low voltage is detected. The LDO is taken out of continuous operation and activated only when needed, eliminating unnecessary power consumption while maintaining voltage regulation capability.
Solution Approach 2:
The patent implements a dynamic control system with voltage detection that adjusts the LDO operation state based on real-time voltage conditions. The system transitions between LDO-on and LDO-off states dynamically, optimizing power consumption while ensuring stable operating voltage when required.
2Stability of the object's composition
If the LDO operates continuously to maintain operating voltage, then voltage stability is improved, but power consumption increases
Solution Approach 1:
The patent implements a feedback mechanism where the voltage detection circuit continuously monitors the operating voltage and provides feedback to the control logic. Based on this feedback, the system determines whether to activate or deactivate the LDO, maintaining voltage stability only when necessary and reducing power consumption when voltage is already adequate.
Solution Approach 2:
Instead of continuous LDO operation, the patent employs periodic voltage monitoring and conditional activation. The system periodically checks voltage levels and activates the LDO only during periods when voltage drops below the threshold, creating an efficient on-demand operation pattern that balances stability and power consumption.
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 significantly reduces power consumption and enhances the efficiency of the AC LED lighting system by minimizing the operation of LDOs and optimizing the voltage regulation, leading to improved power factor and extended lifespan of the LEDs.
Implementation Method 1
employs full-wave rectifier 18 to rectify an AC voltage VAC and provide a DC input voltage VIN
Implementation Method 2
drains current from input power line IN to charge capacitor COUT, so operating voltage VCC is built up
Data Source
AI summary
A LED lighting system efficiently provides an operating voltage powering integrated circuits. A LED string has LEDs segregated into LED groups connected in series. A LED controller has channel nodes connected to the cathodes of the LED groups respectively, and an output node connected to a capacitor providing the operating voltage. The LED controller drains a channel current from a selected channel node among the channel node. The LED controller regulates the channel current to a channel target value corresponding to the selected channel node, and provides a portion of the channel current as a charging current to power and regulate the operating voltage.