Wireless Acoustic Glass Breakage Detector Using Pulsed Microphone Power

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Solution Overview

Problem

Current wireless glass breakage detectors are inefficient in power usage and fail to detect low-frequency sounds typically generated by glass breakage, and existing solutions require high power consumption, making them unsuitable for battery-powered applications.

Innovation Solution

A wireless battery-powered acoustic glass breakage detector using a pulsed microphone power supply, a sample and hold circuit, and AND circuitry to detect explosion-like and flex wave sounds within the 10 Hz to 16 KHz frequency range, with a microprocessor controlling the pulsating currents to minimize power consumption and ensure reliable detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the detector uses continuous power supply to the microphone, then the detection sensitivity and response speed are improved, but the power consumption increases

Engineering Contradiction:
Improvedetection sensitivityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies periodic action by pulsing the microphone power supply at optimized intervals rather than providing continuous power. The microphone is activated only during specific time windows to detect acoustic events, allowing the system to maintain detection sensitivity while dramatically reducing average power consumption for battery-powered operation.

Inventive Principle:
Principle #19Periodic action

2Duration of action of moving object

If the detector uses low stand-by current consumption, then the battery life is extended, but the response speed to sudden acoustic events becomes slow

Engineering Contradiction:
Improvebattery lifeVSAvoidresponse speed
Core Design Contradiction:
Duration of action of moving objectVSSpeed

Solution Approach 1:

The system uses periodic action with optimized pulse timing to balance battery life and response speed. The microphone is pulsed at intervals that allow sufficient time for battery conservation while being frequent enough to capture sudden glass breakage events, achieving both extended battery life and adequate response speed.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system employs feedback mechanisms where the detector continuously monitors for acoustic events and adjusts its operation accordingly. When an event is detected, the system activates processing circuits to analyze the signal, and only returns to low-power mode after confirming no event occurred, optimizing both battery life and response capability.

Inventive Principle:
Principle #23Feedback

3Use of energy by moving object

If the detector ignores irrelevant acoustic events, then the power consumption is reduced, but the detection of actual glass breakage events may be missed

Engineering Contradiction:
Improvepower consumptionVSAvoiddetection accuracy
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The system applies preliminary action by implementing pre-detection filtering that identifies characteristics of glass breakage events before full processing activation. The initial detection stage looks for specific acoustic signatures (such as the characteristic frequency range and waveform patterns of breaking glass) to determine whether to activate the higher-power analysis circuits, reducing power consumption while maintaining detection accuracy for actual events.

Inventive Principle:
Principle #10Preliminary action

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

The solution achieves low power consumption, enabling the detector to operate continuously for 3-5 years on a single battery and effectively detect glass breakage sounds across the relevant frequency range without compromising sensitivity.

Implementation Method 1

a microphone, the microphone being powered by a pulsating microphone current, the microphone being operable for generating pulsed signal data corresponding to sound waves detected thereby

Methodology Applied
Scientific EffectAcoustic detection: Sound

Data Source

PatentEP3201886B1Wireless acoustic glass breakage detector
Publication Date: 2018.08.15 TYCO FIRE & SECURITY GMBH
  • EP3201886B1 patent drawingFigure 1
  • EP3201886B1 patent drawingFigure 2

AI summary

An acoustic glass breakage detector (100) including a pulsating current-powered microphone (104) and operable for generating pulsed signal data corresponding to sound waves detected thereby, a sample and hold circuit (108) operable for converting the pulsed signal data into a voltage level signal and storing the voltage level signal, a sound frequency band pass amplifier (110) operable for ascertaining whether the voltage level signal corresponds to an explosion-like sound typical of an initial glass-breakage sound, a flex wave band pass amplifier (112) operable for ascertaining whether the voltage level signal corresponds to a flex wave typical of an initial glass-breakage sound, and circuitry (114) operable, responsive to ascertaining that the voltage level signal corresponds to an explosion like sound typical of an initial glass-breakage event and that the voltage level signal corresponds to a flex wave typical of an initial glass-breakage sound, for ascertaining that the pulsed signal data is indicative of a glass-breakage event.