Dynamic Filtering Dimmable LED Drivers for Smooth Transitions
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Solution Overview
Problem
LED drivers struggle to provide smooth light output transitions and respond quickly to rapid dimmer setting changes, often resulting in undesirable stepped outputs due to slow filtering and averaging processes.
Innovation Solution
A light driver with an output correction circuit that monitors output signals for rapid changes, deactivates filtering and averaging when necessary, and adjusts the reference voltage to quickly follow dimmer level changes, ensuring smooth dimming without steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If filtering and averaging are applied to the dimmer signal, then output stability is improved, but response speed deteriorates
Solution Approach 1:
The patent applies dynamics by making the filtering and averaging process adjustable rather than fixed. The controller dynamically modifies the degree of filtering and averaging applied to the dimmer signal based on detected output conditions. When rapid output changes are detected, the controller reduces filtering/averaging to improve response speed; when output is stable, the controller increases filtering/averaging to enhance stability. This dynamic adjustment resolves the contradiction between stability and response speed.
2Stability of the object's composition
If filtering and averaging are applied to the dimmer signal, then output ripple is reduced, but transient response deteriorates
Solution Approach 1:
The controller dynamically adjusts the filtering and averaging parameters based on the transient response requirements. During transient conditions (when rapid output changes occur), the controller reduces or disables filtering and averaging to minimize transient response time. During steady-state operation, the controller applies full filtering and averaging to reduce output ripple. This time-varying approach resolves the contradiction between ripple reduction and transient response.
3Stability of the object's composition
If constant filtering and averaging are used, then noise is reduced, but ability to follow rapid dimmer changes deteriorates
Solution Approach 1:
The patent implements dynamic filtering where the filtering characteristics change based on the operational state. The controller continuously monitors output changes and adapts the filtering degree accordingly. When rapid dimmer changes are detected, the controller reduces filtering to improve adaptability to follow the changes. When the system is in steady state, the controller applies stronger filtering to reduce noise. This adaptive approach resolves the contradiction between noise reduction and adaptability.
Data Source
AI summary
A method of driving a light source by a light driver includes measuring a current output signal of the light driver, calculating a percent change in output signal, determining whether the percent change in output signal is greater than or equal to a first threshold, and in response to determining that the percent change in the output signal is greater than or equal to the first threshold, calculating a percent change in reference voltage based on a current reference voltage and a previous reference voltage, determining whether the percent change in reference voltage is less than a second threshold, and in response to determining that the percent change in reference voltage is less than the second threshold, deactivating filtering and averaging of a dimmer signal received from a dimmer for a period of time, and reactivating the filtering and the averaging of the dimmer signal.