LED Driver Circuit Miniaturization via Phase Dimmer PWM Control
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Solution Overview
Problem
Current LED driving circuits are hindered by the large volume of electrolytic capacitors and inductors, which limits miniaturization and increases the risk of premature failures due to temperature, and lack efficient dimming control mechanisms.
Innovation Solution
An LED device with a control unit that includes a PWM controller, allowing for efficient dimming control using a phase dimmer to switch between parallel and series modes based on rectified signal voltage levels, enabling effective dimming control suitable for traditional phase dimmers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrolytic capacitors and inductors are used in LED driving circuits, then voltage rectification and filtering can be achieved, but the circuit volume increases and miniaturization becomes difficult
Solution Approach 1:
The patent removes the electrolytic capacitor from the traditional LED driving circuit, extracting the harmful component that causes volume issues and reliability problems. The rectification function is maintained through alternative circuit topology that eliminates the need for large-capacity electrolytic capacitors, thus solving both the volume expansion and reliability issues simultaneously.
2Reliability
If electrolytic capacitors are used for voltage filtering, then filtering performance is achieved, but the lifetime is shortened due to temperature influence causing premature failures
Solution Approach 1:
The patent extracts the electrolytic capacitor from the circuit to eliminate the reliability issue. By removing this temperature-sensitive component, the patent avoids premature failures caused by thermal degradation, thereby extending the overall system lifetime while maintaining filtering performance through alternative circuit design.
Solution Approach 2:
The patent replaces the short-lived electrolytic capacitor with solid-state components that have significantly longer operational lifetimes and are not susceptible to temperature-related degradation. This substitution uses more reliable, long-lasting components to replace the disposable nature of electrolytic capacitors.
3Power
If inductors and transformers are used in LED driving circuits, then power conversion is achieved, but the device volume increases
Solution Approach 1:
The patent removes traditional inductors and transformers from the circuit topology, extracting the bulky power conversion components. Instead, it employs a solid-state switching circuit with MOSFETs and capacitors that achieves the same power conversion function with dramatically reduced volume, enabling LED driver miniaturization.
4Ease of operation
If traditional phase dimmer control is used, then dimming functionality is achieved, but compatibility with LED PWM switching requires complex control circuits
Solution Approach 1:
The patent designs a control circuit that serves multiple functions: it rectifies the AC input signal, generates PWM switching signals, and interfaces with traditional phase dimmer controls. This multi-functional approach allows the circuit to handle both power conversion and dimming control through a unified design, reducing overall system complexity.
Solution Approach 2:
The patent changes the operating parameters of the control circuit to directly generate PWM signals that are compatible with LED switching characteristics. By adjusting the switching frequency and duty cycle parameters based on the rectified signal, the circuit achieves efficient LED dimming control without requiring additional complex control stages.
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 enables efficient dimming control for LED devices, allowing for miniaturization and improved reliability by utilizing a phase dimmer to control PWM switching, thus overcoming the limitations of existing LED driving circuits.
Implementation Method 1
The rectifying module rectifies the regulated signal and outputs a rectified signal
Implementation Method 2
The PWM controller generates a switching signal for controlling currents flowing through the first LED light string and the second LED light string based on at least a parameter calculated from the rectified signal
Data Source
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AI summary
An LED device is disclosed. The LED device comprises a PWM controller. A phase dimmer produces a regulated signal. The PWM controller converts the regulated signal into a switching signal in a series mode and optionally converts the rectified signal into the switching signal in the parallel mode.