Transformer-Based TVS Testing Circuit

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Solution Overview

Problem

Existing methods for testing transient voltage suppressors (TVSs) in vehicles, such as aircraft, are costly and require grounding the aircraft, which is inconvenient and expensive, especially as TVSs degrade over time and may fail to properly shunt power surges.

Innovation Solution

A system and method that includes a pulse source, transformer, test point, and controller to generate and analyze electrical pulses to determine the operational status of a TVS by comparing reflections of the pulses to threshold values, allowing for in-situ testing during vehicle operation without grounding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If benchtop testing is used to test TVS, then testing accuracy is improved, but cost increases and vehicle operation is disrupted

Engineering Contradiction:
Improvetesting accuracyVSAvoidvehicle operation continuity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent introduces a transformer as an intermediary device that enables electrical isolation between the test equipment and the vehicle's electrical system. The transformer's primary winding connects to the test pulse generator while the secondary winding connects to the TVS under test, allowing accurate measurements to be taken without directly connecting test equipment to the vehicle's power system, thus avoiding disruption to vehicle operation while maintaining testing accuracy

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements a self-service testing mechanism where the TVS under test actively participates in the testing process by shunting the test pulse to ground. The TVS's own functional characteristic (shunting capability) is utilized as the test mechanism, eliminating the need for external benchtop testing equipment and allowing continuous operation during testing

Inventive Principle:
Principle #25Self-service

2Measurement precision

If benchtop testing is used to test TVS, then testing accuracy is improved, but cost increases

Engineering Contradiction:
Improvetesting accuracyVSAvoidtesting cost
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The testing system utilizes the TVS's inherent shunting function as the test mechanism. By applying a test pulse through the transformer and measuring the reflected waveform, the system leverages the TVS's own operational characteristics to perform self-diagnosis, eliminating the need for expensive external benchtop testing equipment and reducing testing costs while maintaining accuracy

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the mechanical/physical benchtop testing system with an electrical reflection-based testing method. Instead of using specialized physical test equipment, the system uses electrical pulse generation and reflection measurement through a transformer, substituting complex mechanical testing infrastructure with simpler electrical measurement techniques

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 cost-effective, in-operation testing of TVSs, reducing the need for expensive benchtop testing and ensuring the proper functioning of TVSs by determining their status without disrupting vehicle operations.

Implementation Method 1

a transformer having a first side coupled to the pulse source and a second side configured to be coupled to the TVS and configured to transfer the electrical pulse to the TVS and to transfer an at least partial reflection of the electrical pulse from the TVS to the first side

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3495829B1Voltage suppressor test circuit and method of testing a voltage suppressor
Publication Date: 2021.01.27 HAMILTON SUNDSTRAND CORP
  • EP3495829B1 patent drawingFigure 1
  • EP3495829B1 patent drawingFigure 2
  • EP3495829B1 patent drawingFigure 3

AI summary

A system for testing a transient voltage suppressor, TVS, (104) configured to be coupled between a bus (106) and a first ground or line (119) to discharge a voltage surge on the bus to the first ground or line includes a pulse source (110) configured to generate an electrical pulse. The system further includes a transformer (120) having a first side (122) coupled to the pulse source and a second side (124) configured to be coupled to the TVS and configured to transfer the electrical pulse to the TVS and to transfer an at least partial reflection of the electrical pulse from the TVS to the first side. The system also includes a test point (138) coupled to the first side of the transformer and configured to receive the at least partial reflection of the electrical pulse.