Universal LED Driver Circuit for AC and DC Input

Solution Overview

Problem

Conventional lighting apparatus driving circuits require a separate apparatus to operate normally with both AC and DC input voltages, leading to increased weight and spatial limitations due to duplicative circuitry.

Innovation Solution

A circuit and method that generate a valley signal based on input voltage to determine whether it's AC or DC, using an AC voltage simulation unit to create a virtual valley signal for DC input, and a switching device controller to manage the LED module's power, eliminating the need for a separate apparatus by controlling the driving voltage and current.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a separate apparatus is added to support both AC and DC input voltages, then the lighting apparatus can operate with both voltage types, but the weight and spatial requirements increase due to duplicative circuitry

Engineering Contradiction:

Improvecompatibility with AC and DC input voltagesVSAvoidweight of lighting apparatus

Core Design Contradiction:

Adaptability or versatilityVSWeight of stationary object

Solution Approach 1:

The driving circuit is designed with a universal input stage that can accept both AC and DC voltages through a single apparatus. The circuit includes voltage detection circuitry that automatically identifies the input type and adjusts operating parameters accordingly, eliminating the need for separate AC-only and DC-only driving circuits. This multi-functional design maintains compatibility with both voltage types while avoiding duplicative components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the previously separate AC driving circuit and DC driving circuit into a single integrated driving apparatus. The combined circuit shares common components such as the power factor correction stage, LED driver circuitry, and control logic, while incorporating intelligent detection to handle both AC and DC inputs through unified processing paths.

Inventive Principle:

Principle #5Merging (Combining)

2Adaptability or versatility

If a separate apparatus is added to support both AC and DC input voltages, then the lighting apparatus can operate with both voltage types, but the spatial requirements increase due to duplicative circuitry

Engineering Contradiction:

Improvecompatibility with AC and DC input voltagesVSAvoidspatial requirements of lighting apparatus

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The driving circuit is designed with a universal input stage that can accept both AC and DC voltages through a single apparatus. The circuit includes voltage detection circuitry that automatically identifies the input type and adjusts operating parameters accordingly, eliminating the need for separate AC-only and DC-only driving circuits. This multi-functional design maintains compatibility with both voltage types while avoiding duplicative components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the previously separate AC driving circuit and DC driving circuit into a single integrated driving apparatus. The combined circuit shares common components such as the power factor correction stage, LED driver circuitry, and control logic, while incorporating intelligent detection to handle both AC and DC inputs through unified processing paths.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If the lighting apparatus uses AC input voltage, then it can operate with AC power supply, but it cannot operate normally with DC input voltage due to overload

Engineering Contradiction:

Improvenormal operation with AC voltageVSAvoidoperation with DC voltage

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The driving circuit incorporates feedback mechanisms that continuously monitor the input voltage characteristics and provide real-time adjustments to operating parameters. When DC voltage is detected, the feedback control modifies the switching duty cycle, current limiting thresholds, and protection circuitry activation levels to prevent overload conditions while maintaining stable LED operation.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The circuit employs dynamic parameter adjustment based on detected input voltage type. The operating characteristics such as switching frequency, current limits, and protection thresholds are dynamically modified according to whether AC or DC input is detected, allowing the same hardware to reliably operate under both voltage types without fixed design limitations.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS9521719B2Circuit for driving lighting apparatus and method thereof

Publication Date: 2016.12.13 MAGNACHIP SEMICON LTD

AI summary

A circuit for driving a lighting apparatus is provided. The circuit includes a valley signal generator configured to generate a valley signal based on an input voltage, an input voltage determining unit configured to determine whether the input voltage corresponds to a direct voltage or a full-wave rectified AC voltage based on the valley signal, an AC voltage simulation unit configured to generate a virtual valley signal when the input voltage is a DC voltage, and a switching device controller configured to control a switching device used to drive an LED module based the determination and at least one of the valley signal and virtual valley signal.