Pulse Heater Abnormality Detection Using Reflected Wave Comparison
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Solution Overview
Problem
Existing methods for detecting abnormalities in pulse heaters, such as partial disconnection, often misinterpret resistance value increases due to heat generation during energization, leading to delayed detection of actual abnormalities.
Innovation Solution
An electric circuit abnormality detection device that uses a pulse generator to input a pulse signal, a directional coupler to extract the reflected wave, and a detection unit with a storage part and calculation part to compare the waveform information of the reflected wave with a reference reflected wave, allowing for early detection of abnormalities without being affected by temperature-induced resistance changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If resistance value measurement is used to detect abnormalities in the pulse heater, then abnormality detection can be performed, but the detection accuracy deteriorates due to interference from heat generation during energization
Solution Approach 1:
The patent performs resistance value measurements at predetermined timing points when the pulse heater is not energized or at low temperature, before heat generation occurs. This preliminary measurement approach captures the baseline resistance value without thermal interference, enabling accurate abnormality detection that is not confounded by temperature-induced resistance changes during operation.
2Speed
If continuous monitoring of resistance value is performed during energization, then real-time detection is achieved, but false positives increase due to temperature-induced resistance changes
Solution Approach 1:
The patent implements periodic measurement at specific timing points rather than continuous monitoring during energization. By measuring at predetermined intervals when thermal effects are minimal or可控, the system achieves real-time detection capability while avoiding the false positives that would result from continuous measurement during high-temperature operation.
Solution Approach 2:
The system performs measurements at predetermined timing points before or during low-power states, capturing resistance values before thermal interference occurs. This timing-based differentiation allows the system to distinguish between normal temperature-induced resistance changes and actual abnormalities.
3Device complexity
If resistance value increase is used as the sole detection criterion, then simple detection logic is achieved, but detection reliability decreases when partial disconnection occurs during heat generation
Solution Approach 1:
The patent establishes baseline resistance values through preliminary measurements at low temperature or non-energized states. By comparing subsequent measurements against this baseline, the system can reliably detect abnormalities even when resistance increases occur during heat generation, without requiring complex detection logic.
Solution Approach 2:
The detection process is segmented into distinct measurement phases: preliminary measurement at low temperature to establish baseline, and subsequent comparison measurements. This segmentation allows simple detection logic at each stage while maintaining high overall reliability through the structured approach.
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 reliable and early detection of abnormalities in electric circuits, such as partial disconnection, by distinguishing between resistance value changes due to heat generation and actual circuit abnormalities, thereby preventing potential failures.
Implementation Method 1
a directional coupler which extracts, from the electric circuit, a reflected wave of the pulse signal inputted from the pulse generator to the electric circuit
Implementation Method 2
since the resistance value of the resistance wire of the pulse heater increases upon heat generation due to energization
Data Source
AI summary
An electric circuit abnormality detection device includes a pulse generator, a directional coupler, and a detection unit. The detection unit includes a reference reflected wave database and a calculation part. The reference reflected wave database stores waveform information of a reference reflected wave inputted from the directional coupler when a pulse signal is inputted to a reference electric circuit that has a same wiring pattern as a pulse heater and does not have an abnormality. The calculation part detects an abnormality in the pulse heater by comparing waveform information of a reflected wave inputted from the directional coupler when the pulse signal is inputted to the pulse heater, with waveform information of the reference reflected wave stored in the reference reflected wave database.