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Articles on Trending Technologies
Technical articles with clear explanations and examples
Electric Traction: Buck and Boost Method of Speed Control of Traction Motors
The circuit diagram of the buck and boost method of speed control of traction motors is shown in the figure.There are two traction motors viz. traction motor-I and traction motor-II. In this method of speed control, the armature of both the traction motors I and II and the motor-generator set are connected in series. This whole series combination is connected across the main supply.When the terminal voltage of the generator is equal to the supply voltage in magnitude but of opposite polarity and the main contactor (MC) is closed, the voltage across the traction motors will be zero and hence ...
Read MoreWhat are the auxiliary equipment used in an electric locomotive?
In addition to the main traction motors, the following additional equipment are required to be installed on an electric locomotive engine −Motor-Generator SetBatteryPantograph Operating EquipmentAir CompressorTraction Motor BlowersHeating EquipmentLet's check the functions of each of these equipment in detail.Motor–Generator SetThe motor-generator set used in the electric locomotives is of the two bearing type and it consists of a series motor and a shunt generator. The speed of the series motor at light load is limited by the ventilating fan and the voltage of the generator is controlled by an automatic voltage regulator (AVR).The generated voltage by the motor-generator set is ...
Read MoreElectric Traction: Calculation of Sag and Tension for Trolley Wire
An overhead wire of large cross-section made of copper or a copper alloy and provides the current required for the trolleys of electric vehicle is known as trolley wire.When a flexible wire is suspended horizontally between two pole supports, it would assume the form of catenary. But in case of tramways, the sag in the trolley wire rarely exceeds 1% to 1.5% of the span length and thus the trolley wire may be considered to hang in the form of a parabola as shown in the figure below.Let, $$\mathrm{Span\: length\: of\: trolley\: wire\: (in \: meters)\, \mathrm{\: =\: }\, 2\mathit{l} ...
Read MoreElectric Traction: Behn Eschenburg Scheme of Regenerative Braking
The method of electric braking of traction motor in which the motor remains connected to the supply line and return the braking energy to the supply system is known as regenerative braking.Figure-1 shows the connection diagram of Behn Eschenburg scheme of regenerative braking. In this scheme, an auxiliary transformer is used to excite the field winding of the traction motor. The armature of the traction motor is connected to the main transformer through a tap changer.A choke coil or iron cored reactor (Reactor-I) is inserted in between the armature of the traction motor and the tap changer as shown in ...
Read MoreWhat are the 42 mobile apps China is allegedly using to spy on the Indian forces?
The IB (Intelligence Bureau) which is the premier intelligence services department of the Government of India has identified a number of mobile apps including many that are developed by Chinese companies. Here's a list of 28 apps that the Digital IT Cell of the Government of India has identified as spyware and malware - Weibo, Wechat, Shareit, Truecaller, UC News, UC Browser, Beautiplus, Newsdog, Viva Video - Qu Video Inc, Parallel Space, Apus Browser, Perfect Corp, Virus Cleaner - Hi Security Lab, CM Browser, MI Community, DU Recorder, Vault Hide - NQ Mobile Security, Youcam Makeup, MI Store, Cachecleaner DU ...
Read MoreWhat are Google Algorithms and what importance do they have in digital marketing?
Google keeps making changes to its algorithms at regular intervals to improve different aspects of user experience on its search engine. These algorithm changes are referred to as 'Updates' by Google and users all over the world are always anxious about these updates. Of course, they come like a bolt from the blue because Google doesn't want to allow unethical users to find a way out too easily.The ImpactIn most cases, it is the digital marketing companies that feel the impact of these periodic updates from Google but it's also true that if these updates hadn't come, the search industry ...
Read MoreWhy are online shopping sites becoming mobile shopping apps?
An online shopping site is a website which can be accessed through a computer which can be either a desktop or laptop. The website can also be accessed through a smartphone or tablet and both are mobile devices. In computers, because of higher data processing capacity and more functionality, all you need to do to access a shopping site is type the URL of the site in the browser and press 'enter'. However, on a mobile device like a smartphone or tablet, you may be able to open a shopping site but won't be able to make transactions, unless you ...
Read MoreDo meetings during work hours hamper productivity?
As long as meetings are brief and not too frequent, they don't adversely affect productivity. I think meetings should have a specific purpose and not just be held as a routine activity just because they look good as a 'best practice'. In that case, it comes very close to being a waste of time, which we can't afford in today's time-crunched schedules. After all, in a process driven environment, what purpose will regular meetings serve other than filtering down of instructions? Today, with all the tools in place right on our workstations, regular instructions and guidelines can be easily conveyed ...
Read MoreWhat is social bookmarking? Step by step explanation?
The term social bookmarking can be misleading for someone who is not particularly familiar with web content development and marketing. It's got nothing to do with the regular bookmarking of websites or web pages that we do by clicking the star icon at the extreme right-hand corner of the URL bar.Actually, social bookmarking is the term used for content aggregation sites where a cross-section of bloggers, SEO professionals, and journalists among others post their content for better distribution and ranking on search engines. Some of the popular social bookmarking websites are Redit.com, Tumblr.com, and Digg.com among others.A Two Way MechanismNow ...
Read MoreWhat are the most popular QA forums for general people?
According to me, the most popular Q&A site is Qries, while Linked In Answers, Yahoo Answers, Quora and Answers.com among others are renowned Q&A forums. Qries enjoys a very high level of credibility mainly because of the type of people who answer the questions on Qries. The best part of Qries is that it covers all domains and subjects and you hardly find any left behind. As a business resource Q&A forums are not all that popular and rank way down at the eighth spot but for general queries, they are very popular, especially sites like Qries, which also have ...
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