High-Frequency, Pulsed-Current GTA Welding

1972 ◽  
Author(s):  
William A. Roden
Keyword(s):  
High Frequency ◽  
Gta Welding ◽  
Pulsed Current

scholarly journals Two-Phase Resonant Converter to Drive High-Power LED Lamps

Electronics ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 53 ◽  
Author(s):  
Christian Brañas ◽  
Rosario Casanueva ◽  
Francisco J. Díaz ◽  
Francisco J. Azcondo
Keyword(s):  
Dynamic Response ◽  
High Power ◽  
High Frequency ◽  
Pulsed Current ◽  
Resonant Converter ◽  
Two Phase ◽  
Street Lighting ◽  
Spice Model ◽  
Flicker Effect ◽  
Output Filter

This paper presents the design and modeling of a two-phase resonant converter that drives a LED lamp with a high-frequency pulsed current free of instabilities and flicker effect, fulfilling the recommendations of the IEEE PAR 1789-2015, so that it enables visible light-based communication at a 10 kB/s bit rate. The dynamic study of the converter takes into consideration the effect of the reflected impedance of the output filter on the AC side. In order to evaluate the dynamic response of the converter, a Spice model is defined. A 120 W prototype intended for street lighting applications has been built to validate the analysis and modeling.

Electroplasticity in AZ31B subjected to short-duration high-frequency pulsed current

2019 ◽  
Vol 125 (18) ◽  
pp. 185104 ◽  
Author(s):  
Jingyi Zhao ◽  
Zhencheng Ren ◽  
Hao Zhang ◽  
Guo-Xiang Wang ◽  
Yalin Dong ◽  
...  
Keyword(s):  
Short Duration ◽  
High Frequency ◽  
Pulsed Current

Heat Transfer Modelling and Investigation of the Effect of Pulse Frequency and Current in Pulsed Current Gas Tungsten Arc Welding

2014 ◽  
Vol 592-594 ◽  
pp. 395-399
Author(s):  
A. Prabakaran ◽  
R. Sellamuthu ◽  
Sanjivi Arul
Keyword(s):  
Heat Transfer ◽  
Weld Pool ◽  
Arc Welding ◽  
Gta Welding ◽  
Gas Tungsten Arc Welding ◽  
Transfer Model ◽  
Pulsed Current ◽  
Current Frequency ◽  
Gas Tungsten Arc ◽  
Gas Tungsten

Gas Tungsten Arc Welding (GTAW) involves several process parameters. In Pulsed Current GTAW frequency of pulse and pulse to time ratio differentiates the characteristics of weld pool geometry of from GTAW. In the present work a simple heat transfer model for Pulsed Current GTA welding was developed and the weld pool dimensions were experimentally verified with AISI 1020 steel. Relationship between speed and pulsed current frequency on weld pool dimension was studied. Weld pool dimension of pulsed and non-pulsed GTAW is studied.

Effect of Pulsed Current Gas Tungsten Arc Welding Parameters on Microstructure of Titanium Alloy Welds

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
M. Balasubramanian ◽  
V. Jayabalan ◽  
V. Balasubramanian
Keyword(s):  
Grain Size ◽  
Titanium Alloy ◽  
Weight Ratio ◽  
Gta Welding ◽  
Pulse Frequency ◽  
Welding Parameters ◽  
Pulsed Current ◽  
Thin Sections ◽  
Gas Tungsten Arc ◽  
Gas Tungsten

Titanium is one of the most important nonferrous metals, which finds extensive application in aerospace and chemical industries, because of its light weight, excellent corrosion resistance and high strength to weight ratio. Single pass gas tungsten arc (GTA) welding of thin sections of Ti–6Al–4V was accomplished with pulsing current technique and was found to be superior to conventional continuous current process in terms of grain refinement in the fusion zone. In this investigation, an attempt was made to study the effect of pulsed current GTA welding parameters on titanium alloy weld characteristics such as grain size and hardness. It was revealed that at an optimum value of 6 Hz pulse frequency and 80A peak current, the hardness was maximum and the grain size was minimum. Pulsing current in inert gas welding was found to be beneficial in titanium welding.

Reduction of pressure ulcer size with high-voltage pulsed current and high-frequency ultrasound: a randomised trial

2016 ◽  
Vol 25 (12) ◽  
pp. 742-754 ◽  
Author(s):  
A. Polak ◽  
J. Taradaj ◽  
A. Nawrat-Szoltysik ◽  
M. Stania ◽  
P. Dolibog ◽  
...  
Keyword(s):  
Pressure Ulcer ◽  
High Voltage ◽  
High Frequency ◽  
Randomised Trial ◽  
Pulsed Current ◽  
High Frequency Ultrasound ◽  
Ulcer Size ◽  
Frequency Ultrasound

Mechanical Properties and Consolidation of WC-8wt.%Ni Hard Materials by HFIHS and PCAS

2007 ◽  
Vol 124-126 ◽  
pp. 1153-1156 ◽  
Author(s):  
In Kyoon Jeong ◽  
Hwan Cheol Kim ◽  
Jung Mann Doh ◽  
Jin Kook Yoon ◽  
In Yong Ko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Particle Size ◽  
Grain Size ◽  
High Frequency ◽  
Sintering Behavior ◽  
Pulsed Current ◽  
Hard Materials ◽  
Short Time ◽  
High Frequency Induction

Two methods, High-Frequency Induction-Heated Sintering (HFIHS) and Pulsed Current Activated Sintering (PCAS), were utilized to consolidate WC-8wt.%Ni hard materials. The demonstrated advantages of these processes are rapid densification to near theoretical density in a relatively short time and with insignificant change in grain size. The hardness, fracture toughness, and the relative density of the dense WC–8Ni composites produced by HFIHS and PCAS were investigated. And the effect of variation in particle size of WC powder on the sintering behavior and mechanical properties were investigated.

scholarly journals GaN 2DEG Varactor-Based Impulse Suppression Module for Protection Against Malicious Electromagnetic Interference

2020 ◽  
Vol 49 (11) ◽  
pp. 6798-6805 ◽  
Author(s):  
Chien-Fu Shih ◽  
Liann-Be Chang ◽  
Ming-Jer Jeng ◽  
Yu-Li Hsieh ◽  
Ying-Chang Li ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
High Frequency ◽  
Pulsed Current ◽  
Dimensional Electron ◽  
Interference Immunity ◽  
Electromagnetic Pulses ◽  
Capacitance Variation ◽  
Metal Semiconductor Metal ◽  
Attractive Candidate ◽  
Dimensional Electron Gas

Abstract A GaN-based metal–semiconductor–metal varactor with a two-dimensional electron gas (2DEG) layer is proposed and fabricated. The capacitance variation of this fabricated varactor biased at different external voltages is studied and measured, and the frequency-dependent capacitance and resistance of the varactor are simulated by a corresponding empirical formula. A high-frequency protective filter is further constructed and placed under a large pulsed-current injection in a malicious electromagnetic interference immunity test. The results show that the proposed GaN-based module can reduce the large pulsed current to an acceptably small level. Thus, the GaN-based 2DEG varactor is an attractive candidate for applications designed to protect the upcoming 5G high-frequency system from risks such as electrostatic discharge, lightning, and electromagnetic pulses.

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