LED Driving Apparatus Digital Control Eliminates External Capacitor
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Solution Overview
Problem
Existing LED driving apparatuses require a separate high-capacitance external capacitor, increasing circuit area and manufacturing cost, due to the use of a GM amplifier in the control circuit for switching power rectified on the primary side.
Innovation Solution
The LED driving apparatus controls switching of the power converting circuit based on its switching period and demagnetization time, eliminating the need for a separate external capacitor by using a digital scheme with operational amplifiers and digital-to-analog converters to provide a reference voltage and feedback control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a GM amplifier is used in the control circuit for switching power rectified on the primary side, then the LED can be driven with AC power, but a separate high-capacitance external capacitor is required, increasing circuit area and manufacturing cost
Solution Approach 1:
The patent extracts and removes the external capacitor from the circuit by implementing a digital control scheme using operational amplifiers and digital-to-analog converters that generate the necessary switching signals internally, eliminating the need for the separate high-capacitance external capacitor while maintaining AC power compatibility
Solution Approach 2:
The patent replaces the traditional analog GM amplifier-based control system with a digital control system using operational amplifiers and digital-to-analog converters, which generates switching signals through digital processing and eliminates the need for external capacitors
2Ease of operation
If a GM amplifier is used in the control circuit for switching power rectified on the primary side, then the LED can be driven with AC power, but manufacturing cost increases due to the external capacitor
Solution Approach 1:
The patent extracts and removes the external capacitor from the circuit by implementing a digital control scheme using operational amplifiers and digital-to-analog converters that generate the necessary switching signals internally, eliminating the need for the separate high-capacitance external capacitor while maintaining AC power compatibility
Solution Approach 2:
The patent replaces expensive external capacitors with integrated digital-to-analog converter circuits that can be implemented using standard operational amplifiers and digital logic, reducing component costs and simplifying manufacturing
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 approach reduces noise resistance characteristics, decreases circuit area and manufacturing cost, and eliminates the need for an external capacitor terminal, thereby lowering manufacturing costs.
Implementation Method 1
a transformer transferring power from the primary side to the secondary side
Data Source
AI summary
A light emitting diode (LED) driving apparatus includes a power converting unit and a driving controlling unit. The power converting unit switches input power to supply driving power to at least one LED. In one example, the driving controlling unit controls the supplying of the power based on a switching period of the power converting unit and a demagnetization time in the switching period. In another example, the driving controlling unit controls the supplying of the power based on the input power, a switching period of the power converting unit, and a drain voltage by the switching.