Alarm Line Testing via Periodic Load Current

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing hazard alarm systems face challenges in testing for impermissibly high line resistance under load conditions, as conventional methods are not compliant with DIN EN 54 Part 13 standards and cannot be directly applied to signaling lines due to polarity reversal and changing voltage requirements.

Innovation Solution

A method involving an end module that generates a test current equal to or greater than a detector's alarm current during a brief test time, allowing for periodic testing of the alarm line's functionality without interfering with emergency power operations, and includes a timer and voltage monitoring to ensure energy efficiency and correct operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional quiescent current monitoring is used to test alarm lines, then the testing method is simple and energy consumption is low, but the test does not verify functionality under load conditions as required by DIN EN 54 Part 13 standards

Engineering Contradiction:

Improveline functionality verification under loadVSAvoidtesting procedure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements periodic testing by alternating between test phases (generating test current equal to detector alarm current) and normal operation phases. The control panel periodically interrupts the alarm line voltage for brief test intervals, allowing functionality verification under load conditions without continuous energy consumption or system disruption

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent changes the current parameter during testing by generating a test current that equals the alarm current of a detector, rather than using the constant quiescent current. This parameter change allows verification of line functionality under load conditions while maintaining compatibility with standard detector operating parameters

Inventive Principle:

Principle #35Parameter changes

2Reliability

If polarity reversal testing is applied to alarm lines as done in other alarm systems, then comprehensive line testing is achieved, but the alarm line voltage requirements are violated and detectors may malfunction

Engineering Contradiction:

Improveline testing comprehensivenessVSAvoiddetector malfunction risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Instead of reversing polarity as done in other alarm systems, the patent inverts the approach by maintaining correct polarity and using a test current magnitude equal to alarm current. This alternative method achieves comprehensive testing without exposing detectors to harmful polarity reversal conditions

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the current magnitude parameter rather than polarity. By generating a test current equal to the alarm current while maintaining correct voltage polarity, the system achieves thorough functionality verification without causing detector malfunction

Inventive Principle:

Principle #35Parameter changes

3Reliability

If continuous test current generation is performed to verify line functionality under load, then comprehensive functionality testing is achieved, but energy consumption increases and may interfere with emergency power operation

Engineering Contradiction:

Improveline functionality verificationVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent applies partial action by performing tests only for brief intervals rather than continuously. The test current is generated only during short test periods, providing sufficient functionality verification while minimizing energy consumption and avoiding interference with emergency power operation

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentEP2169645B1Test of reporting lines on a danger reporting assembly

Publication Date: 2011.05.11 NOVAR GMBH

Figure 1~2
Figure 3

AI summary

The method involves measuring the current of the alarm system loop, and comparing with a reference value. An error report of the shortfall of the reference value is generated. A testing current is generated at the alarm system loop by the terminal module periodically during testing period. The alarm system loop is supplied with a constant line voltage. The testing current is equal to the current of an alarm. The generation of the testing current by the terminal module is activated for a time tolerated by the alarms by breaking and re-switching the line voltage. An independent claim is included for a danger alarm system, which has a central unit.