LED Lighting Device Power Supply Circuit with Voltage Limiter

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Solution Overview

Problem

The high cost of manufacturing household appliances with specific power transformers for each lighting device powered by light-emitting diodes, due to varying electrical parameters, and the risk of damage to regulator circuits from excessive input voltages.

Innovation Solution

A power supply circuit with a limiting circuit between the transformer and regulator, which adjusts the electrical signal to a predetermined value, allowing the same transformer to be used across different lighting devices and protecting the regulator circuit from overvoltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a specific power transformer is designed for each lighting device with different electrical parameters, then the lighting device operates reliably, but the manufacturing cost increases

Engineering Contradiction:
Improvelighting device operation reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies universality by designing a single power transformer that can serve multiple lighting devices with different electrical parameters. The transformer is made universal through the addition of a regulator circuit that adapts the output to match the specific requirements of each lighting device, eliminating the need for multiple specialized transformers.

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

Solution Approach 2:

The patent uses parameter changes by incorporating a regulator circuit that can dynamically adjust electrical parameters (voltage, current) of the transformer output. This allows the same transformer to provide different electrical characteristics to different lighting devices, resolving the contradiction between reliability and manufacturing cost.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the electrical signal from the power transformer is not limited, then the transformer operates efficiently, but the regulator circuit may be damaged by excessive voltage

Engineering Contradiction:
Improvetransformer operation efficiencyVSAvoidregulator circuit safety
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by placing a limiting circuit between the power transformer and the regulator circuit. This limiting circuit proactively restricts the electrical signal from the transformer before it reaches the regulator circuit, preventing potential damage while allowing the transformer to operate at full efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses an intermediary approach by introducing a limiting circuit as a mediator component between the power transformer and the regulator circuit. This intermediary element protects the regulator circuit from excessive voltage while not interfering with the transformer's efficient operation, effectively resolving the contradiction.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2094062B1Lighting device for a home appliance, in particular a exhaust hood
Publication Date: 2011.10.05 FAGORBRANDT
  • EP2094062B1 patent drawingFigure 1~3
  • EP2094062B1 patent drawingFigure 2
  • EP2094062B1 patent drawingFigure 4

AI summary

The appliance has a lighting device (1) e.g. halogen lamp, formed by LEDs, and a power supply circuit (2) for powering the lighting device. The supply circuit includes a power supply transformer (3) supplying power to a regulatory circuit (4). The regulatory circuit regulates a supply parameter of the lighting device, where the parameter is based on type and/or number of LEDs. The supply circuit includes a limiter circuit (5) mounted between the transformer and the regulatory circuit so as to limit value of electrical output voltage (VST) of the transformer to a predetermined value.