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 More
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 More
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 More
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 More
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 More
It all begins with what purpose your website is going to serve. For the sake of better understanding, let's look at the logic theory of computing. Just as conventional languages fit a certain environment, computer languages are also created for specific programming environments that go on to run the websites that are built for those environments. For instance, if you're learning Japanese it would be for interaction with Japanese people and not for interaction with German people. Next, it's about another aspect of the environment that you would like to go to - a democracy with freedoms or a closed ... Read More
In this article, we are going to create a canvas with a text cursor on hover using FabricJS. text is one of the native cursor style available which can be used in the FabricJS canvas too.FabricJS provides various types of cursors such as default, all-scroll, crosshair, col-resize, row-resize, etc. that reuse the native cursor under the hood. The hoverCursor property sets the style of the cursor when hovered over a canvas object.Syntaxnew fabric.Canvas(element: HTMLElement|String, { hoverCursor: String }: Object)Parameterselement − This parameter is the element itself which can be derived using document.getElementById() or the id of the element ... Read More
In this article, we are going to create a canvas with a progress cursor on hover using FabricJS. progress is one of the native cursor style available which can be used in the FabricJS canvas too.FabricJS provides various types of cursors such as default, all-scroll, crosshair, col-resize, row-resize, etc. that reuse the native cursor under the hood. The hoverCursor property sets the style of the cursor when hovered over a canvas objectSyntaxnew fabric.Canvas(element: HTMLElement|String, { hoverCursor: String }: Object)Parameterselement − This parameter is the element itself which can be derived using document.getElementById() or the id of the element ... Read More
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 More
In this article, we are going to create a canvas with a help cursor on hover using FabricJS. help is one of the native cursor style available which can be used in the FabricJS canvas too. FabricJS provides various types of cursors such as default, all-scroll, crosshair, col-resize, row-resize, etc. that reuse the native cursor under the hood. The hoverCursor property sets the style of the cursor when hovered over a canvas object.Syntaxnew fabric.Canvas(element: HTMLElement|String, { hoverCursor: String }: Object)Parameterselement − This parameter is the element itself which can be derived using document.getElementById() or the id of the ... Read More