The DC motor is an important part of an equipment in many industrial applications requiring variable speed and load characteristics due to its ease of controllability. Nowadays, there are lots of good-quality motor speed controllers on the market. However, their costs are relatively high. A speed controller with both low cost and good performance will be highly marketable, especially for small ...

This paper presents a novel control method to improve the efficiency of low-voltage DC-DC converters at light loads. Pulse Width Modulation (PWM) converters have poor efficiencies at light loads, while pulse frequency modulation (PFM) control is more efficient for the same cases. Switching losses constitute a major portion of the total power loss at light loads. To decrease the switching losses...

The electro discharge machining (EDM), one of the methods used in the machining industry and a non-traditional manufacturing method, the electro erosion process does not depend on the hardness of material and offers a way to process materials of very complex geometry with very fine and high precision by using cheap electrode materials, which make it a preferred method. In this study, effect of ...

A selective electrochemical method for the determination of uric acid was developed by using nano poly cresol red modified glassy carbon electrode. This new material has been characterized by Scanning Electron Microscopy, cyclic voltammetry and Differential pulse voltammetry. This modified electrode shows excellent electrocatalytic activity towards the oxidation of uric acid in the presence of ...

Watt’s bath and pulse reverse (PR) electrodeposition is used to produce spherical nickelmultiwall carbon nanotubes (Ni-MWCNT) of 2.00, 0.93, 1.63 and 6.71 μm diameter and a variety ofsize distributions. For 60 cycles, an absolute electrodeposition current of 18 A/dm2 is applied atcurrent ratios of ii = idissolution/ideposition = 0, 0.077, 0.200 and 0.368. A simple exponential equation isfitted ...

background & aim : pulse oximetry is a frequently used and standard non-invasive method for monitoring oxygen (o2)-saturation in blood. many factors including dark skin and pigmentation may effect on rate of saturation of the blood oxygen absorbed by pulse oximetry. the effect of nail polish and/or henna color on blood oxygen has not been yet identified and the present study has been carried ou...

Austenitic stainless steel sheets have gained wide acceptance in the fabrication of components, which require high temperature resistance and corrosion resistance such as metal bellows used in expansion joints in aircraft, aerospace and petroleum industries. In the case of single pass welding of thinner sections of this alloy, Pulsed Current Micro Plasma Arc Welding (PCMPAW) has been found bene...

In this paper, we have experimentally investigated the optimized bias current of semiconductor optical amplifiers (SOAs) to achieve high-speed input pulse train amplification with high gain and low distortion. Variations of the amplified output pulse duration with the amplifier bias currents have been analyzed and, compared to the input pulse duration, the amplified output pulse duration is bro...