Fire Alarm Loop Break Location via Current Direction Detection

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Solution Overview

Problem

Conventional fire notification facilities face challenges in quickly identifying and locating breaks in loop transmission paths, leading to delays in recovery and maintenance when a break occurs, which compromises facility reliability.

Innovation Solution

The integration of current direction detecting units, including a current detection resistor and display units, allows for the easy identification of break sections by determining current direction changes along the loop transmission path, enabling rapid repair and maintenance by displaying normal and reverse current directions with color coding on a disaster-prevention facility map.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a loop transmission path is used to ensure reliability against break faults, then reliability is improved, but the ability to quickly identify and locate breaks deteriorates

Engineering Contradiction:
ImprovereliabilityVSAvoidtime to identify and locate breaks
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies color-coded display indicators (e.g., green for normal current direction, red for reverse current direction) to visually represent the state of current flow in different sections of the loop transmission path. This allows operators to quickly identify break locations by observing color changes on a facility map, transforming the abstract electrical state into intuitive visual information that speeds up troubleshooting while maintaining the reliable loop configuration.

Inventive Principle:
Principle #32Color changes

2Measurement precision

If conventional break monitoring is implemented, then break fault detection is achieved, but the precision of break location identification deteriorates

Engineering Contradiction:
Improvebreak location identification precisionVSAvoiddifficulty of detecting and measuring break location
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent divides the loop transmission path into multiple sections, each monitored by individual current direction detecting units positioned at specific intervals. When a break occurs, the system identifies which specific section experiences reverse current flow by comparing readings from adjacent detecting units. This segmentation approach transforms a single difficult measurement problem into multiple localized, easily identifiable measurements, precisely pinpointing break locations between specific detecting units.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If current direction detecting units are added to identify breaks, then ease of locating breaks is improved, but device complexity increases

Engineering Contradiction:
Improveease of locating breaksVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The current direction detecting units are designed with multi-functionality, serving both as fire monitoring devices and as break location identification sensors. The same hardware infrastructure (transmission path, detectors, receiver) is utilized for dual purposes: normal fire safety monitoring and break fault diagnosis. This universal approach avoids adding separate dedicated systems, thereby improving ease of break location identification while minimizing the increase in overall device complexity.

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

This solution enables swift identification and repair of break locations, ensuring facility reliability by facilitating at-a-glance detection of current direction changes and facilitating quick recovery of the loop transmission path.

Implementation Method 1

a current direction detecting unit (38) which detects a current direction of a current flowing through the loop transmission path (12) in a predetermined direction as a current normal direction and detects a current flowing in a direction opposite to the normal current direction as a current reverse direction

Methodology Applied
Scientific EffectOhm's Law: Ohm's Law

Data Source

PatentEP3745370B1Fire alarm equipment
Publication Date: 2023.12.20 HOCHIKI CORP
  • EP3745370B1 patent drawingFigure 1
  • EP3745370B1 patent drawingFigure 2
  • EP3745370B1 patent drawingFigure 3

AI summary

[Problem] When a break fault occurs in a loop transmission path and signal transmission is allowed from both sides of the location of the break to continue fire monitoring, a break section is easily found on a receiver side. [Solution] A fire detector 18 is connected to a loop transmission path 12 connected to a receiver 10. When the loop transmission path 12 is normal, a communication connection is made from a transmitting unit 23 to the fire detector 18 to monitor fire. When a break fault occurs in the loop transmission path 12, a break monitoring control unit 28 turns switching circuit units 30a and 30b ON to connect a termination of the loop transmission path 12 to the transmitting unit 23 to make a communication connection from both ends of the loop transmission path 12 to the fire detector 18 to monitor fire. To the loop transmission path 12 a relay 20 including a current direction detecting function with a unique address set thereto is provided, detecting a current normal direction at normal and a current reverse direction at the time of occurrence of a break for transmission to the receiver 10. When a break occurs in the loop transmission path 12, a break section determining unit 32 of the receiver 10 determines, as a break section, a section in which the current normal direction detected by a plurality of said relays 20 is changed to the current reverse direction, and notifies as such.