Connector Terminals Research Articles

Aging evaluation of fuse holders of BWR nuclear power plant

The aging evaluation of a typical fuse holder, which is used in a BWR-5 nuclear plant, is discussed in this paper. This evaluation considered the guidelines of the NUREG-1760. A fuse holder, class R, has been considered. It has a wire gauge in the 500 kcmil – 4 Cu/Al range. It is used for a nominal current between 201 A and 400 A. It has 3 poles with a box-type terminal and a reinforcing clip, for blade-type fuses. The evaluation was carried out in two steps using the ANSYS® code. In the first, the operation of the fuse holder without aging was simulated. A three-dimensional model was used. The numerical solution requires the coupling of electrical, thermal, and mechanical analyses. It can be done with a single model. The mesh elements are Solid 232, Solid 291, and Solid 187. The model was refined at the clip holder and connector terminals. The model has 3,379,780 nodes and 2,387,463 elements. Its natural frequencies and the distribution of temperature, voltage, and stresses were obtained. The aging analysis was carried out in the second step after sixty years of operation. The loss of 1 mm in the thickness of the fastener, caused by corrosion or wear in the fuse assembly, was considered. The results showed that the vibration modes occurred with lower natural frequencies when inadequate contact occurred. Besides, changes in the other operating parameters were observed.

Multi-Objective Optimization of Injection Molding Parameters for Manufacturing Thin-Walled Composite Connector Terminals.

The rapid development of new energy vehicles demands significant improvements in connector structures and performance standards. Wire harness connectors, crucial for linking various electrical components, face challenges due to their small size and thin-walled structure, which can lead to dimensional shrinkage and warping during injection molding. To address these issues, this study optimizes the injection molding process by fine-tuning parameters such as melt temperature, mold temperature, injection time, holding pressure/time, and cooling time. By integrating the Taguchi method with grey relational analysis, the study enhances the molding process for thin-walled composite connectors. This combined approach provides a comprehensive framework for optimizing multiple quality objectives and improving the overall performance of injection-molded composite components.

Current and temperature-rise effect of contact condition for connection terminals in UHVDC converter stations

The heating phenomenon of connector terminals in converter stations has become increasingly common, it has become a serious safety hazared affecting the operation of UHV lines. This paper determined the overlapping model of Al plate-Al plate based on the heating phenomenon of connector terminals in converter stations, conducted the tests which included disassembly and assembly contact surface roughness impact test, pressing force impact test, operation impact test, electric composite grease impact test, anti-loosening measure impact test. Analyzed the main influencing factors of current and temperature-rise for connector terminals heating, and analyzed the influence rule of each factor for current and temperature-rise of connector terminals. Test shows that: bolt tightening torque and electric composite grease was the main influencing factors for current and temperature-rise of connector terminals, and bolt tightening moment was the first main factor, bolt looseness and the performance degradation of electric composite grease directly causes an increase in the contact resistance and temperature rise level of the connector terminals.

PCB 커넥터의 무납땜 결선을 위한 PRESS-FIT 성형 연구

Recently, regulations on lead used in automobiles and electronics have been tightened. In particular, in the case of the existing PCB connector terminals, the use of lead is high, so the demand for the development of solderless PCB connector terminals to replace them is increasing. This paper describes the research on the development of the PCB connector terminal of the solderless connection method through the development of the Press Fit EoN shape terminal. In order to analyze the difference according to the press fit EoN product shape, the test sample was taken out by making two different types of progressive molds using the EoN outer corner “R” molding method of the press fit that has the greatest effect on the insertion force. Insertion and release tests were performed on the PTH with the extracted sample, and the required force was measured and compared. The press-fit EoN terminal developed in this study was applied to the soul power window switch of “Company K” and is being used as an eco-friendly PCB connector terminal.

초고속 프레스 작업에서의 펀치 수명 및 콘택트 타발 품질 향상

In recent years, the manufacture connector terminals of electronic devices require an accuracy of several microns and high productivity, thus the need to develop the ultra-high speed press technology. However, increased impulse and vibration of ultra-high speed press have reduced durability of stamping die and induced serious tool wear. To solve this problem, we investigate the changes of vibrations occurring in the die and press machine under ultra-high speed working condition by using a piezoelectric sensor. Moreover, by analyzing the design parameters such as stroke, stripper movement, and collision velocity of the die, impulse and vibration were decreased, thus improving the punch life by 50% under 2,000 SPM (stroke per minute) condition

CAD/CAM simulation of the connector terminals based on SolidWorks and its extensional software

This article uses the connector terminal’s three-dimensional entity as the model, and then imports it into 3D finite element analysis software-SolidWorks, the feasible stamping process plans and the multistage progressive die design are proposed by using the plug-in Logopress 3.The processing of the mold parts simulation and NC programming Steps are simulated by using the SolidCAM.Aiming at the problems of complex edge shape, large number of process stages and low overall design efficiency of terminal multistage progressive die.The application provides a reference for subsequent die design and die manufacturing.

Investigation on strength of resistance spot welding joint of copper and brass using various filler materials

Copper and Brass are widely used in Auto electrical industries due to their good electrical conductive properties. This is possible as free electrons in metals can move through, allowing metals to conduct electricity. Resistance spot welding process (RSW) is the highly preferred welding process especially for electrical connector terminals because of its reliability over Copper and brass joints and attained importance in automotive sectors. Present work is focused on the behavior of various filler materials used in between Copper and Brass in resistance spot welding process by which the strength of weld joints is being analyzed.

Narrow bandpass cryogenic filter for microwave measurements

An ultra-wide stopband hairpin bandpass filter with integrated nonuniform transmission lines was designed and fabricated for highly sensitive measurements at cryogenic temperatures down to millikelvin and a frequency range of 10 Hz-10 GHz. The scattering matrices of the filter were characterized at T = 4.2 K. The filter provides a stopband from 10 Hz to 2.2 GHz and from 2.3 GHz to 10 GHz with more than 50 dB and 40 dB of amplitude suppression, respectively. The center frequency of the passband is f0 = 2.25 GHz with a bandwidth Δf = 80 MHz. The maximum insertion loss in the passband is 4 dB. The filter has a 50 Ω input and output impedance, SubMiniature version A connector termination, and significantly reduced form factor. The wide stopband frequency range and narrow passband in conjunction with small dimensions make the filter suitable to use it as a part of a high sensitive readout for superconducting quantum circuits, such as superconducting quantum bits and cryogenic parametric amplifiers.

Surface Morphology and Characteristics of Electroplated Au/Ni Films for Connector Contact Materials

The surfaces of the connector terminals used for electrical connection of components are electroplated with Sn, Au, or Ag in order to improve reliability. For electronic devices that require particularly high reliability, hard gold is used. The characteristics of gold deposits of various surface morphologies were examined. Gold films with increased surface roughness exhibited superior friction and wear properties without a large increase in contact electrical resistance after friction testing. Increasing the surface roughness also resulted in higher solder adhesion strength and improved corrosion resistance to sulfur dioxide gas.

Mitigation of connector damage during disengaging DC loads using polymeric arc suppressor

Although connectors are generally not designed to disconnect electrical loads under power, in some circumstances they are mated and unmated under load. For instance, during repairs, diagnostic procedures, or when blown fuses are replaced under short circuit conditions. At dc system voltage levels significantly higher than the minimum arc voltage of metals such hot-disconnections may impact the reliability of the connection, the electrical distribution system, and automotive safety. Gassing polymers mounted onto connector terminals may reduce the damage resulting from disconnections under dc loads, and therefore enable connector designs with occasionally (forward running) arcing terminals. The authors discuss the effects of different types of gassing polymers on arc extinction and connector damage of standard automotive connectors.

Fretting corrosion and the reliability of multicontact connector terminals

The harsh operating environment of the automotive application makes the semi-permanent connector susceptible to intermittent high contact resistance which eventually leads to failure. Fretting corrosion is often the cause of these failures. However, laboratory testing of sample contact materials produces results that do not correlate with commercially tested connectors. A multicontact (M-C) reliability model is developed to bring together the fundamental studies and studies conducted on commercially available connector terminals. It is based on fundamental studies of the single contact interfaces and applied to commercial multicontact terminals. The model takes into consideration firstly, that a single contact interface may recover to low contact resistance after attaining a high value and secondly, that a terminal consists of more than one contact interface. For the connector to fail, all contact interfaces have to be in the failed state at the same time.

Friction properties of perfluorinated polyethers for hot‐dipped tin low‐level separable electrical contacts

AbstractTin coatings are used as a final protection for cuprous substrates involved in low‐level electrical contacts. High friction forces and fretting phenomena remain a cause of electrical failure of connector terminals, and so should be minimised. A lubricant layer can improve the life and reliability of connector terminals but such a layer must ensure low and stable resistance values even under severe temperature conditions. Work has been undertaken to investigate the lubricant layer most suitable for the protection of tinned electrical contacts. Perfluorinated polyethers (PFPEs) were chosen for their inertness. The aim was to correlate various physico‐chemical properties of branched or linear PFPEs, with their frictional and electrical properties. The long‐term electrical properties of a contact are shown to be linked to the initial wear mode in the contact.