LED Driving Apparatus Non-Insulation Circuit Triac Dimmer

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Solution Overview

Problem

Existing LED driving circuits face challenges in miniaturization, power factor improvement, and compatibility with triac dimmers, leading to inefficiencies and flickering issues due to complex component requirements and slow response times.

Innovation Solution

A non-insulation type LED driving apparatus with a simplified circuit structure, utilizing a rectifier, inductor, capacitor, and diode configuration, along with a switch controller that generates a reference voltage to control the switch operation, allowing for efficient power input and rapid response to input voltage changes, thereby improving power factor and compatibility with triac dimmers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a flyback method is used for power factor correction, then power factor is improved, but circuit complexity increases due to requiring photo coupler and transformer

Engineering Contradiction:
Improvepower factorVSAvoidcircuit complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent extracts and removes the transformer and photo coupler from the circuit, replacing them with a direct feedback mechanism using a voltage dividing circuit and comparator. This eliminates unnecessary components while maintaining power factor correction functionality through a simplified control approach.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The control circuit is designed to perform multiple functions: power factor correction, LED current control, and dimmer compatibility. By integrating these functions into a single control mechanism using the voltage dividing circuit and comparator, the patent reduces overall circuit complexity while achieving universal functionality.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Stability of the object's composition

If feedback band is set to 10-20Hz to supply predetermined current, then current stability is maintained, but response speed becomes slow and triac dimmer compatibility is poor

Engineering Contradiction:
Improvecurrent stabilityVSAvoidresponse speed
Core Design Contradiction:
Stability of the object's compositionVSSpeed

Solution Approach 1:

The patent implements a dynamic feedback mechanism where the comparator continuously compares the divided voltage with a reference voltage and adjusts the switching element in real-time. This dynamic adjustment allows the system to respond quickly to voltage changes while maintaining current stability, achieving both stability and fast response simultaneously.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses a voltage feedback mechanism where the output voltage is divided and fed back to the comparator. This feedback loop allows the system to detect voltage changes immediately and adjust the switching element accordingly, providing both stability and fast response to triac dimmer signals.

Inventive Principle:
Principle #23Feedback

3Reliability

If bleeder resistor is used to supply power after rectification, then circuit operation is maintained, but flickering occurs and turn-on time increases when brightness is lowered by triac dimmer

Engineering Contradiction:
Improvecircuit operationVSAvoidflickering and turn-on time
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The capacitor serves dual purposes: it maintains circuit operation during low brightness conditions and provides the necessary holding charge for the control circuit. This self-service approach eliminates the need for a separate bleeder resistor while preventing flickering and ensuring reliable turn-on behavior under dimmer control.

Inventive Principle:
Principle #25Self-service

4Loss of energy

If standard transformer components are used in power factor correction circuit, then power factor is improved, but developmental expenses and time increase

Engineering Contradiction:
Improvepower factorVSAvoiddevelopmental expenses and time
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The patent replaces expensive standard transformer components with inexpensive passive components (resistors, capacitors, diodes) and a simple control circuit. This substitution dramatically reduces component costs and simplifies manufacturing while maintaining power factor correction functionality through an alternative circuit topology.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 miniaturization, reduces component count, and provides a rapid response to input changes, improving power factor and enabling seamless operation with triac dimmers, thus enhancing the efficiency and reliability of LED driving circuits.

Implementation Method 1

a rectifier rectifying an alternate current (AC) voltage applied from external power

Methodology Applied
Scientific EffectRectification:

Implementation Method 2

a power supply unit supplying driving power to the light emitting unit, and having an inductor, a capacitor and a diode

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2458722B1LED driving apparatus
Publication Date: 2014.04.30 SAMSUNG ELECTRONICS CO LTD
  • EP2458722B1 patent drawingFigure 1~2
  • EP2458722B1 patent drawingFigure 3~4
  • EP2458722B1 patent drawingFigure 5~6

AI summary

Provided is an LED driving apparatus capable of improving a power factor through a non-insulation type simplified circuit structure, being adaptable to a triac dimmer, being miniaturized to be economical, and including: a light emitting unit having at least one LED; a rectifier rectifying an alternate current(AC) voltage applied from external power; a power supply unit supplying driving power to the light emitting unit, and having an inductor connected to an output terminal of the light emitting unit; a switch controller receiving a voltage outputted from the rectifier to generate a reference voltage in proportion to the voltage outputted from the rectifier, and comparing the reference voltage with an input voltage generated by detecting a current flowing in the inductor, and controlling an on or off operation of a switch so as to proportion a waveform connecting peaks of the current flowing in the inductor to a waveform represented from the input voltage by turning the switch off at a point of time at which the voltages coincide with each other; and a switch connected to the switch controller to control power inputted from the light emitting unit.