Flicker-Free LED Dimmer Signal Conditioner
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Solution Overview
Problem
LED lamps experience significant flickering at low light intensities due to small variations in input voltage, especially in long distribution networks or when multiple lamps are connected, causing stress for humans and animals.
Innovation Solution
A signal conditioner and method that filters and converts electrical signals to drive LED lamps, synchronizing power with zero-crossing of the electrical distribution network, using an active bleeder circuit to absorb residual energy and a controller to manage voltage, along with energy storage and feedback mechanisms to maintain stable light intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If TRIAC based controller is used to vary lighting intensity, then light dimming is achieved, but flickering occurs at low intensity
Solution Approach 1:
The patent applies periodic action by using a signal conditioner that generates a periodic waveform synchronized with the AC power distribution network. The controller activates the LED lamp in periodic cycles synchronized with the zero-crossing of the mains voltage, ensuring that power is delivered in controlled periodic intervals rather than continuously varying through TRIAC phase control. This periodic synchronization eliminates the random flickering caused by TRIAC activation at arbitrary voltage points.
Solution Approach 2:
The signal conditioner acts as an intermediary device between the AC power distribution network and the LED lamp. It conditions the incoming electrical signal by filtering, converting, and segmenting it into a clean periodic waveform before delivering it to the LED driver circuit. This intermediary processing removes voltage disturbances and residual energy that would otherwise cause flickering, while the active bleeder circuit serves as another intermediary to specifically handle residual energy discharge.
2Adaptability or versatility
If conduction angle tracking is used in LED lamps, then backward compatibility with incandescent lamps is maintained, but flickering is amplified in long distribution networks
Solution Approach 1:
The patent extracts and removes the problematic conduction angle tracking control circuit from the LED lamp system. Instead of relying on the LED lamp's internal control circuit to track the conduction angle of the supply voltage (which amplifies flickering in long distribution networks), the invention provides a clean, conditioned periodic waveform through the signal conditioner that eliminates the need for such tracking. This extraction of the problematic control mechanism stops the amplification of voltage disturbances.
Solution Approach 2:
The signal conditioner creates a copied and improved version of the incandescent lamp control waveform. Rather than directly controlling the LED lamp with the raw AC waveform (which causes flickering), the system generates a replicated periodic waveform that mimics the smooth operation of incandescent lamps but is optimized for LED operation. This copied waveform is synchronized with the AC network but free from the disturbances that affect long distribution networks.
3Loss of energy
If residual energy is not discharged from LED lamps, then energy is wasted, but active bleeder circuit adds system complexity
Solution Approach 1:
The active bleeder circuit is designed to automatically discharge residual energy from the LED lamp and associated capacitors without requiring external intervention or complex control systems. The circuit self-regulates by detecting the presence of residual energy and activating the appropriate discharge path. This self-service approach efficiently manages residual energy while keeping the control logic simple, as the bleeder circuit operates autonomously based on voltage threshold detection.
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 effectively eliminates flickering, providing stable and controlled light intensity by synchronizing power delivery with the zero-crossing of the electrical network, reducing energy dissipation, and using active bleeder circuits to manage residual energy, thus minimizing stress on humans and animals.
Implementation Method 1
an active load rapidly absorbing the residual energy on the lamp side of the conditioner when the conditioner cut-off the power to the device
Implementation Method 2
creating a signal conditioner capable of filtering, converting, segmenting and generally producing a periodic waveform from an electrical source
Implementation Method 3
synchronizing to the zero-crossing of the electrical power distribution network
Data Source
AI summary
The invention generally comprises creating a signal conditioner that is capable of filtering, converting, segmenting and producing a periodic waveform from an electrical source, converting in into an electrical signal to drive an electrical device, such as a LED lamp, so that the behavior of the device driven by the electrical signal enables the device to perform a function that is practically free of the variations present in the main electrical source.