Plasma Arc Torch Secondary Starting Circuit
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Solution Overview
Problem
Automated plasma arc torches face challenges in initiating a pilot arc efficiently, leading to energy radiation and noise generation due to high voltage circuits, which complicates the starting process and stability of the plasma stream.
Innovation Solution
A secondary power circuit is introduced proximate to the plasma arc torch, generating a high voltage pulse on a third element to initiate a pilot arc, reducing the energy radiation and noise by minimizing the high voltage circuit's length and using a conductive insert to create a spark between the electrode and the tip, thus ionizing the gas and forming a plasma stream.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a high voltage generating circuit is provided at or near the torch head to reduce the length of the circulating path, then the radiation of energy and noise to the surrounding environment is reduced, but a large inductor is required in series with the electrode or tip lead to isolate the high voltage generating circuit, resulting in a relatively large high voltage circuit that still radiates energy and noise
Solution Approach 1:
The patent extracts the high voltage generating function from the main power supply and places it in a separate secondary starting circuit near the torch head. This isolates the high voltage generation to a localized area, reducing the circulating path length and minimizing electromagnetic radiation and noise to the surrounding environment while avoiding the need for a large series inductor.
Solution Approach 2:
The patent introduces a third element as an intermediary component in the secondary starting circuit. This third element facilitates the generation of high voltage pulses without requiring a large inductor, serving as a mediator that enables isolated high voltage generation near the torch head while minimizing electromagnetic interference.
2Reliability
If the entire torch lead is charged up to obtain a high voltage signal at the torch tip to start the arc, then the pilot arc can be initiated, but the power supply and the entire torch lead radiate energy into the surroundings, generating noise in the power supply and surrounding electronic systems
Solution Approach 1:
The patent segments the starting process into two distinct circuits: a main power supply circuit and a separate secondary starting circuit. The secondary starting circuit generates high voltage pulses only when needed for arc initiation, rather than continuously charging the entire torch lead. This segmentation enables reliable arc starting while minimizing continuous energy radiation and noise generation.
Solution Approach 2:
The secondary starting circuit operates periodically only when arc initiation is required, generating high voltage pulses on demand rather than continuously charging the torch lead. This periodic operation reduces the time during which energy radiation and noise occur, while still ensuring reliable arc starting when needed.
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 allows for self-starting with minimal delay, reduces electromagnetic interference, and enables rapid automatic restart of the plasma arc, providing a stable and uniform plasma stream with reduced energy consumption and noise.
Implementation Method 1
A secondary power circuit is disposed proximate the plasma arc torch and in electrical communication with the third element. The secondary power circuit is configured to generate a high voltage pulse on the third element to initiate a first arc to start the plasma arc torch.
Implementation Method 2
The pilot arc heats and subsequently ionizes the gas. Further, the ionized gas is blown out of the torch and appears as a plasma stream
Implementation Method 3
The conductive insert is configured to create a spark between the electrode and the tip, thus ionizing the gas and forming a plasma stream
Data Source
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AI summary
A plasma arc torch includes an electrode, a tip, a third element, and a secondary power circuit. The electrode is disposed within the plasma arc torch and adapted for electrical connection to a cathodic side of a power supply. The tip is positioned distally from the electrode and adapted for electrical connection to an anodic side of the power supply during piloting. A plasma chamber is formed between the electrode and the tip. The third element is disposed near a proximal end of the plasma chamber. The secondary power circuit is disposed proximate the plasma arc torch and in electrical communication with the third element. The secondary power circuit is configured to generate a high voltage pulse on the third element using input to secondary power circuit to initiate a first arc to start the plasma arc torch.