Ambient-Light LED Control via Switch-Mode Power Supply Pins

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing LED lamps require manual lighting control, leading to energy waste and reduced lifespan due to neglect, and existing motion-sensing lamps lack effective ambient light-based control solutions.

Innovation Solution

A lighting control system utilizing a switch-mode power supply with a photosensor and resistor circuit connected to a PWMD or LD pin, sensing ambient light intensity to automatically turn LED lights on or off.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If manual lighting control is used, then device complexity is reduced, but energy consumption increases and lamp lifespan decreases

Engineering Contradiction:
Improvecontrol system complexityVSAvoidenergy consumption
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The lighting system automatically controls its own operation through the photosensor detecting ambient light levels and the control circuit adjusting LED output accordingly, eliminating the need for manual user intervention while optimizing energy consumption based on actual lighting conditions

Inventive Principle:
Principle #25Self-service

2Loss of energy

If motion-sensing control is implemented, then energy consumption is reduced, but device complexity increases

Engineering Contradiction:
Improveenergy consumptionVSAvoidcontrol system complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent combines the photosensor-based ambient light detection with the existing switch-mode power supply control circuitry, integrating the control function into the power supply module rather than adding a separate motion-sensing control system, thereby reducing overall device complexity while maintaining energy-saving benefits

Inventive Principle:
Principle #5Merging (Combining)

3Loss of energy

If automatic lighting control is added, then energy consumption is reduced, but ease of operation decreases

Engineering Contradiction:
Improveenergy consumptionVSAvoiduser control convenience
Core Design Contradiction:
Loss of energyVSEase of operation

Solution Approach 1:

The system autonomously monitors ambient light conditions through the photosensor and automatically adjusts LED lighting without requiring user intervention, making the operation as simple as leaving the switch in the on position while the system self-regulates based on environmental conditions

Inventive Principle:
Principle #25Self-service

4Device complexity

If photosensor control circuit is integrated into power supply, then device complexity is reduced, but manufacturing precision requirements increase

Engineering Contradiction:
Improvecircuit integration levelVSAvoidcircuit connection precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The control circuit is designed to utilize existing components and pins within the switch-mode power supply module (such as the PWMD pin for pulse-width modulation control), making the same power supply module capable of both power conversion and lighting control functions, thereby reducing overall device complexity while using standard manufacturing processes

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

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

Enables automatic LED lighting control based on ambient light, reducing energy consumption and extending lamp lifespan without altering the power supply layout, enhancing user convenience and willingness to use.

Implementation Method 1

a photosensor (21) to sense the ambient light intensity

Methodology Applied
Scientific EffectPhotosensor light sensing: Photoelectric Effect

Data Source

PatentEP4601415A1Lighting control systems
Publication Date: 2025.08.13 LEE IN OK
  • EP4601415A1 patent drawingFigure 1
  • EP4601415A1 patent drawingFigure 2
  • EP4601415A1 patent drawingFigure 3

AI summary

The lighting control system includes a switch-mode power supply and a control circuit. The switch-mode power supply has an input terminal for connection to a power source and an output terminal for connection to a LED light source and further includes a PWMD pin and a linear dimming (LD) pin. The control circuit includes a photosensor and a resistor connected in series and is connected at one end to a DC voltage and grounded at the other end. The junction between the photosensor and the resistor is connected to the PWMD pin or the LD pin. The photosensor is adapted for sensing ambient light intensity to make the control circuit output a control voltage. The control voltage is transmitted to the switch-mode power supply via the PWMD pin or the LD pin, so that the LED light source is turned on or off.