LED Lighting Apparatus with Energy Storage for AC Operation
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Solution Overview
Problem
LEDs cannot be directly operated on AC voltage due to the narrow operating window caused by varying voltage values, making it impossible to connect them directly to AC voltage supplies without an adapting circuit.
Innovation Solution
An LED lighting apparatus that includes a rectifier device to convert AC voltage to a rectified DC voltage, a switching arrangement to adjust the forward voltage of LEDs, and a control device to synchronize the LED current with the AC voltage, along with an energy storage module to bridge mains dropouts and maintain consistent illumination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If LEDs are directly connected to AC voltage supply, then the structural space and simplicity are improved, but the operation reliability deteriorates due to the narrow operating window and varying voltage values
Solution Approach 1:
The patent introduces a current sink device as an intermediary component between the AC voltage supply and the LEDs. This current sink acts as a mediator that converts the varying AC voltage into a controlled current that remains within the LED's narrow operating window, thereby enabling direct AC connection without compromising reliability.
Solution Approach 2:
The patent transforms the voltage-based control approach into a current-based control approach. By using a current sink device, the system changes the operating parameter from voltage (which varies with AC supply) to current (which can be precisely controlled within the LED's operating window), resolving the contradiction between simplicity and reliability.
2Stability of the object's composition
If a rectifier circuit is used to convert AC voltage, then the voltage stability is improved, but the device complexity increases due to additional components
Solution Approach 1:
The current sink device performs multiple functions simultaneously: it rectifies the AC voltage, regulates the current within the LED operating window, and provides power factor correction. By combining these functions into a single component, the patent achieves voltage stability without proportionally increasing circuit complexity.
Solution Approach 2:
The patent merges the rectification function and current regulation function into a single current sink device. This consolidation reduces the number of separate components needed compared to traditional approaches that would use separate rectifier circuits and current regulation circuits.
3Use of energy by moving object
If the LED current is synchronized with AC voltage, then the power factor is improved, but the control complexity increases
Solution Approach 1:
The current sink device automatically synchronizes the LED current with the AC voltage waveform through its inherent control mechanism. The device self-regulates to maintain synchronization and achieve power factor correction without requiring complex external control circuits or additional synchronization components.
Solution Approach 2:
The patent implements a feedback mechanism where the control device monitors the AC voltage and automatically adjusts the LED current to maintain synchronization. This feedback-based approach achieves power factor improvement through simple, automatic adjustment rather than complex open-loop control.
4Reliability
If an energy storage module is added to bridge mains dropouts, then the illumination continuity is improved, but the device complexity and cost increase
Solution Approach 1:
The energy storage module (capacitor) is pre-charged during normal AC operation to store electrical energy. When a mains dropout occurs, this pre-stored energy is immediately discharged to maintain LED illumination, providing seamless continuity without requiring complex detection or switching mechanisms.
Solution Approach 2:
The patent uses an energy storage capacitor to cushion against the harmful effect of mains dropouts. The capacitor is charged in advance during stable operation and serves as a buffer that absorbs the shock of voltage interruptions, maintaining illumination during brief outages without adding complex protection circuits.
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
Enables reliable operation of LEDs on AC voltage supplies by maintaining consistent illumination and power factor, preventing flicker and ensuring the LEDs operate within their optimal voltage range, even during mains dropouts.
Implementation Method 1
The LED lighting apparatus (1) comprises a rectifier device (5), which rectifies an AC voltage of an AC voltage supply (2) into a rectified supply voltage (11) with a supply current
Implementation Method 2
The LED lighting apparatus (1) comprises an energy storage module (13), which is designed for supplying the at least one LED luminous unit (7) and provides a storage voltage (18) for a storage operating mode
Implementation Method 3
The LEDs are embodied as light-emitting diodes and can be embodied uniformly white or can emit different colours
Data Source
AI summary
An LED lighting apparatus is provided. The apparatus has an LED luminous unit having multiple plurality LEDs and a switching arrangement. The LED luminous unit has different forward voltages in different switching states. The apparatus also has a control device for driving the LED luminous unit and a current sink device in a normal operating mode, in which the forward voltage and the LED current of the LED luminous unit are adapted to an instantaneous value of a supply voltage. An energy storage module of the apparatus provides a storage voltage and supplies the storage voltage to the LED luminous unit. The control device drives the LED luminous unit and the current sink device in a storage operating mode, such that the forward voltage and the LED current of the LED luminous unit are adapted to an instantaneous value of the storage voltage.