LED Driver Circuit Using Open-Loop Buck Converter
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Solution Overview
Problem
Current LED lighting devices require power supply systems to convert AC power to DC, increasing cost, size, and weight, and consuming more power, necessitating a more efficient solution for driving light emitting diode modules.
Innovation Solution
A lighting device incorporating a power factor correction circuit, a non-regulated isolation DC to DC converter, and a regulated non-isolation DC to DC converter, where the non-regulated isolation DC to DC converter is an open-loop controlled buck converter, allowing for efficient power conversion and driving of light emitting diode modules without the need for a transformer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a power supply system with close-loop flyback isolation converter is used to drive LED modules, then reliable power conversion is achieved, but the cost, size, and weight increase significantly
Solution Approach 1:
The patent extracts and removes the transformer component from the power supply system, replacing the traditional close-loop flyback isolation converter with an open-loop controlled buck converter. This extraction eliminates the heavy magnetic components while maintaining power conversion functionality through alternative circuit topologies that use capacitors and switching elements instead of transformers.
Solution Approach 2:
The invention replaces expensive, heavy, and complex close-loop control circuits with simpler, lighter, and more cost-effective open-loop control architecture. The simplified circuit design uses readily available components with shorter operational lifecycles acceptable for LED driving applications, reducing overall system cost and weight.
2Reliability
If a traditional power supply system with transformer is used, then electrical isolation is achieved, but the volume and cost increase by 30%
Solution Approach 1:
The patent removes the transformer from the power supply architecture, eliminating the need for bulky magnetic components. Electrical isolation functions are achieved through alternative means such as capacitive coupling and circuit topology design, maintaining safety and performance without the volume penalty of traditional transformer-based isolation.
Solution Approach 2:
The invention replaces the mechanical/magnetic transformer-based isolation system with an electronic circuit-based approach using switching elements, capacitors, and controlled rectification. This substitution eliminates heavy magnetic fields and large physical components while achieving the same electrical isolation objective through electronic means.
3Stability of the object's composition
If close-loop controlled flyback isolation converter is used, then stable output voltage is maintained, but pulse width modulation controllers are required increasing circuit complexity
Solution Approach 1:
The patent eliminates the need for complex close-loop feedback control by using open-loop controlled buck converter topology that inherently provides stable output through its circuit design. The stability is achieved through proper component selection and circuit configuration rather than active feedback control, simplifying the overall system architecture.
Solution Approach 2:
The power supply circuit is designed to self-regulate and maintain stable output voltage through its inherent circuit characteristics and component properties, without requiring external pulse width modulation controllers or complex feedback mechanisms. The circuit serves itself by using the load characteristics and component parameters to automatically maintain stability.
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 reduces the volume and cost of the power supply system by 30% and improves efficiency by more than 5% compared to close-loop flyback isolation converters, while eliminating the need for pulse width modulation controllers, resulting in a simpler circuit design.
Implementation Method 1
The power factor correction circuit performs a power factor correction on an AC power source and outputs a corrected DC voltage
Implementation Method 2
the non-regulated isolation DC to DC converter comprises a first transformer electrically isolating the corrected DC voltage and the output voltage
Implementation Method 3
at least one light emitting diode module, wherein each of the light emitting diode modules comprises a plurality of light emitting diodes
Data Source
AI summary
A lighting device is provided, having at least one light emitting diode module, a power factor correction circuit, a non-regulated isolation DC to DC converter and at least one regulated non-isolation DC to DC converter. The power factor correction circuit performs a power factor correction on an AC power source and outputs a corrected DC voltage. The non-regulated isolation DC to DC converter generates an output voltage in a predetermined voltage range according to the corrected DC voltage, wherein the non-regulated isolation DC to DC converter is an open-loop controlled buck DC to DC converter. The regulated non-isolation DC to DC converter generates a fixed current or a fixed voltage according to the output voltage output from the non-regulated isolation DC to DC converter, thereby driving the light emitting diode module.