Electrical generator

In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. The reverse conversion of electrical energy into mechanical energy is done by a motor; motors and generators have many similarities. A generator forces electrons in the windings to flow through the external electrical circuit. It is somewhat analogous to a water pump, which creates a flow of water but does not create the water inside. The source of mechanical energy may be a reciprocating or turbine steam engine, water falling through a turbine or waterwheel, an internal combustion engine, a wind turbine, a hand crank, compressed air or any other source of mechanical energy.

Auto cad Version history

Official Name Release Date of release Comments


AutoCAD Version 1.0 1 1982, December DWG R1.0 file format introduced.

AutoCAD Version 1.2 2 1983, April DWG R1.2 file format introduced.

AutoCAD Version 1.3 3 1983, August

AutoCAD Version 1.4 4 1983, October DWG R1.4 file format introduced.

AutoCAD Version 2.0 5 1984, October DWG R2.05 file format introduced.

AutoCAD Version 2.1 6 1985, May DWG R2.1 file format introduced.

AutoCAD Version 2.5 7 1986, June DWG R2.5 file format introduced.

AutoCAD Version 2.6 8 1987, April DWG R2.6 file format introduced. Last version to run without a math co-processor.

AutoCAD Release 9 9 1987, September DWG R9 file format introduced.

AutoCAD Release 10 10 1988, October DWG R10 file format introduced.

AutoCAD Release 11 11 1990, October DWG R11 file format introduced.

AutoCAD Release 12 12 1992, June DWG R11/R12 file format introduced. Last release for Apple Macintosh.

AutoCAD Release 13 13 1994, November DWG R13 file format introduced. Last release for Unix, MS-DOS and Windows 3.11.

AutoCAD Release 14 14 1997, February DWG R14 file format introduced.

AutoCAD 2000 15.0 1999, March DWG 2000 file format introduced.

AutoCAD 2000i 15.1 2000, July

AutoCAD 2002 15.2 2001, June

AutoCAD 2004 16.0 2003, March DWG 2004 file format introduced.

AutoCAD 2005 16.1 2004, March

AutoCAD 2006 16.2 2005, March

AutoCAD 2007 17.0 2006, March DWG 2007 file format introduced.

AutoCAD 2008 17.1 2007, March Annotative Objects introduced. First release for the x86-64 versions of Windows XP and Vista.

AutoCAD 2009 17.2 2008, March Revisions to the user interface including the option of a Microsoft Office 2007-like tabbed ribbon.

AutoCAD 2010 18.0 2009, March 24 DWG 2010 file format introduced. Parametrics introduced. Mesh 3D solid modeling introduced. Both 32-bit and 64-bit versions of AutoCAD 2010 and AutoCAD LT 2010 are compatible with and supported under Microsoft Windows 7.

AutoCAD 2011 18.1 2010, March 25 Surface Modeling, Surface Analysis and Object Transparency introduced.

Cad File formats

AutoCAD's native file format, DWG, and to a lesser extent, its interchange file format, DXF, have become de facto standards for CAD data interoperability. AutoCAD in recent years has included support for DWF, a format developed and promoted by Autodesk for publishing CAD data. In 2006, Autodesk estimated the number of active DWG files to be in excess of one billion.


In the past, Autodesk has estimated the total number of DWG files in existence to be more than three billion.

Auto cad Vertical programs

Autodesk has also developed a few vertical programs, for discipline-specific enhancements. AutoCAD Architecture (formerly Architectural Desktop), for example, permits architectural designers to draw 3D objects such as walls, doors and windows, with more intelligent data associated with them, rather than simple objects such as lines and circles. The data can be programmed to represent specific architectural products sold in the construction industry, or extracted into a data file for pricing, materials estimation, and other values related to the objects represented. Additional tools allow designers to generate standard 2D drawings, such as elevations and sections, from a 3D architectural model. Similarly, Civil Design, Civil Design 3D, and Civil Design Professional allow data-specific objects to be used, allowing standard civil engineering calculations to be made and represented easily. AutoCAD Electrical, AutoCAD Civil 3D, AutoCAD Map 3D, AutoCAD Mechanical, AutoCAD MEP, AutoCAD P&ID, AutoCAD Plant 3D and AutoCAD Structural Detailing are other examples of industry-specific CAD applications built on the AutoCAD platform

Auto cad Student versions

AutoCAD is licensed at a significant discount over commercial retail pricing to qualifying students and teachers, with both a 14 month and perpetual license available. The student version of AutoCAD is functionally identical to the full commercial version, with one exception: DWG files created or edited by a student version have an internal bit-flag set (the "educational flag"). When such a DWG file is printed by any version of AutoCAD (commercial or student), the output will include a plot stamp / banner on all four sides. Objects created in the Student Version cannot be used for commercial use. These Student Version objects will 'infect' a commercial version DWG file if imported[


The Autodesk student community provides registered students with free access to different Autodesk applications

AutoCAD Freestyle

Built on the AutoCAD platform, AutoCAD Freestyle is a simplified, low-cost (US$149) application that makes it easy to create accurate, professional-looking 2D drawings and sketches

AutoCAD LT

AutoCAD LT is a lower cost version of AutoCAD with reduced capabilities first released in November 1993. AutoCAD LT, priced at $495, became the first product in the company's history priced below $1000 to bear the name 'AutoCAD'. In addition to being sold directly by Autodesk, it can also be purchased at computer stores, unlike the full version of AutoCAD which must be purchased from official Autodesk dealers. Autodesk developed AutoCAD LT so that they would have an entry-level CAD package to compete in the lower price level.