LED Driving Circuitry for Multi-Wavelength Smoke Detection

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Solution Overview

Problem

Conventional smoke detectors using radioactive materials are undesirable due to safety concerns and varying operational characteristics of LEDs at different wavelengths require distinct drive currents, making it challenging to maintain consistent and efficient power supply across varying voltage ranges in hazard detection systems.

Innovation Solution

The implementation of a smoke detection system with LED driving circuitry that provides a consistent and reliable drive current to optical sources operating at different wavelengths, using independently derived drive currents from a common power signal through low dropout regulators, ensuring efficient power usage across a range of voltages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple optical sources operating at different wavelengths are used to detect particles of different sizes, then the detection capability is improved, but the power consumption increases and becomes difficult to manage

Engineering Contradiction:

Improvedetection capabilityVSAvoidpower consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent divides the power management into separate channels, with each optical source having its own dedicated current regulation circuit. This segmentation allows each LED to receive its specific drive current independently, optimizing power consumption for each wavelength while maintaining overall detection capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each optical source is provided with customized drive current characteristics tailored to its specific wavelength and operational requirements. The circuitry provides different current levels to different LEDs (e.g., higher current to blue LEDs, lower current to infrared LEDs) to optimize both detection performance and power efficiency for each local component.

Inventive Principle:

Principle #3Local quality

2Reliability

If LED driving circuitry provides consistent drive current to optical sources, then the reliability is improved, but the device complexity increases

Engineering Contradiction:

Improveoperational consistencyVSAvoidcircuit complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces dedicated current regulation circuitry as intermediary components between the power supply and each optical source. These regulator circuits act as mediators that translate the general power input into precise, consistent drive currents for each LED, ensuring reliable operation while isolating the complexity from the overall system architecture.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If different drive currents are provided to optical sources at different wavelengths, then the measurement precision is improved, but the difficulty of detecting and measuring power consumption increases

Engineering Contradiction:

Improvesmoke particle detection accuracyVSAvoidpower consumption monitoring

Core Design Contradiction:

Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The current regulation circuitry incorporates feedback mechanisms that continuously monitor the actual current flowing through each optical source and adjust the drive signal accordingly. This feedback ensures precise current delivery optimized for each wavelength, while the same circuits can report power consumption data to enable monitoring and management.

Inventive Principle:

Principle #23Feedback

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 solution enables reliable and efficient operation of LEDs in smoke detectors across different voltage ranges, reducing the need for radioactive materials and ensuring consistent smoke readings while minimizing power consumption and enhancing safety features in hazard detection systems.

Implementation Method 1

Multiple optical sources such as light emitting diodes may be used in a photoelectric smoke sensor to detect particles of different sizes

Methodology Applied

Scientific EffectLight emitting diode: Light Emitting Diode

Implementation Method 2

Photoelectric smoke sensors can operate by pulsing the LEDs and measuring a response in a light sensor

Methodology Applied

Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentUS9622301B2Smoke detector with regulated constant-current circuit for driving optical sources

Publication Date: 2017.04.11 GOOGLE LLC

AI summary

Systems and methods for driving optical sources operating at different wavelengths within a smoke sensor are described herein. Multiple optical sources such as light emitting diodes may be used in a photoelectric smoke sensor to detect particles of different sizes. Photoelectric smoke sensors can operate by pulsing the LEDs and measuring a response in a light sensor. The signal measured at the light sensor changes based on the quantity of particles existing in a smoke chamber. Each optical source may have different operational characteristics and thus require different drive currents to operate. LED driving circuitry according to embodiments discussed herein provide a consistent and reliable drive current to each optical source, while maximizing efficiency of power consumption across a range of possible voltages provided by different power sources.