Piezoelectric Tamper Detection Circuit for Utility Meters

Solution Overview

Problem

Existing utility meters lack effective and cost-efficient methods to detect tampering, particularly movements that do not activate mechanically moving conductive ball detection circuitry, posing a risk of resource theft and safety hazards.

Innovation Solution

A tamper alarm circuit utilizing a piezoelectric ceramic capacitor to detect mechanical strain, coupled with an amplification and detection circuit that generates an alarm when a predetermined voltage threshold is reached, allowing for the identification and notification of potential meter tampering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanically moving conductive ball detection circuitry is used, then tampering detection capability is provided, but the device complexity and manufacturing cost increase

Engineering Contradiction:

Improvetampering detection capabilityVSAvoiddetection circuitry complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical conductive ball system with a piezoelectric ceramic capacitor-based detection circuit. The piezoelectric element converts mechanical stress from tampering attempts into electrical signals, eliminating the need for mechanical moving parts and complex conductive ball mechanisms. This substitution reduces device complexity while maintaining tampering detection reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the detection parameter from mechanical conductivity changes (conductive ball) to electrical voltage generation (piezoelectric effect). By monitoring voltage signals generated by the piezoelectric capacitor in response to mechanical stress, the system achieves tampering detection with simpler circuitry and lower manufacturing costs.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If a mechanically moving conductive ball detection circuitry is used, then tampering detection is provided, but manufacturing cost increases due to hand soldering requirements

Engineering Contradiction:

Improvetampering detection capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical conductive ball system with a piezoelectric ceramic capacitor-based detection circuit. The piezoelectric element converts mechanical stress from tampering attempts into electrical signals, eliminating the need for mechanical moving parts and complex conductive ball mechanisms. This substitution reduces device complexity while maintaining tampering detection reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The piezoelectric ceramic capacitor is a inexpensive, readily available electronic component that can be easily manufactured using standard surface mount technology. Replacing expensive hand-soldered mechanical components with affordable, easily manufactured electronic parts significantly reduces manufacturing costs while maintaining detection effectiveness.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If a mechanically moving conductive ball detection circuitry is used, then tampering detection is provided, but certain types of movement may not be detected

Engineering Contradiction:

Improvetampering detection capabilityVSAvoiddetection coverage for movement types

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent replaces the mechanical conductive ball system with a piezoelectric ceramic capacitor-based detection circuit. The piezoelectric element converts mechanical stress from tampering attempts into electrical signals, eliminating the need for mechanical moving parts and complex conductive ball mechanisms. This substitution reduces device complexity while maintaining tampering detection reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the detection parameter from mechanical conductivity changes (conductive ball) to electrical voltage generation (piezoelectric effect). By monitoring voltage signals generated by the piezoelectric capacitor in response to mechanical stress, the system achieves tampering detection with simpler circuitry and lower manufacturing costs.

Inventive Principle:

Principle #35Parameter changes

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 the detection of tampering through physical movement, reducing costs and improving safety by providing a reliable method for utility companies to monitor and respond to potential tampering incidents.

Implementation Method 1

the present invention utilizes the piezoelectric properties of a ceramic capacitor to detect movement of the meter

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS7847690B2System and method for detecting tampering of a utility meter

Publication Date: 2010.12.07 ELSTER ELECTRICITY LLC

AI summary

A tamper alarm circuit for detecting a tampered condition of a utility meter is disclosed. The tamper alarm circuit has a transducer coupled to an amplification circuit which is coupled to a detection circuit, the detection circuit generating an alarm condition when the detection circuit determines that a voltage signal generated by the transducer and amplified by the amplification circuit has reached a predetermined threshold.