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Mirazli Furniture And Interior
posted 2 weeks 2 days ago
perkhidmatan pembekal dan pemasangan..
bidai kayu meranti
jam azan digital
tikar getah mozek
tikar getah nipis
tikar getah tebal
sebarang pertanyaan watssap
posted 3 weeks 5 days ago
با سلام می خواستم راجع به کنترل کیفیت مطالب رو یاداشت کنم امیدوارم که بتونم کار مثمر سمری در این خصوص صورت بدم. ممنون از زحمات همه دوستان. از همه دوستان خواهش میکنم تجربیاتشون رو در خصوص کنترل کیفیت برای همه به اشتراک بزارن
1.1 (a). A 25mm Squarecross-section Bar Of Length 300mm Carries An Axial Compressive Load Of 50kn. Determine The Stress Set Up Ip The Bar And Its Change Of Length When The Load Is Applied. For The Bar Material E = 200 Gn/m2. [80 Mn/m2; 0.12mm.l
posted 1 month 2 weeks ago
1.1 (A). A 25mm squarecross-section bar of length 300mm carries an axial compressive load of 50kN. Determine the stress set up ip the bar and its change of length when the load is applied. For the bar material E = 200 GN/m2. [80 MN/m2; 0.12mm.l
Alternator Or Synchronous Generator
posted 2 months 3 weeks ago
Alternator or Synchronous Generator
Definition of Alternator
The definition of alternator is hidden in the name of this machine itself. An alternator is such a machine which produces alternation electricity. It is a kind of generators which converts mechanical energy into alternating electrical energy. It is also known as synchronous generator.
History of Alternator
Michael Faraday and Hippolyte Pixii gave the very first concept of alternator. Michael Faraday designed a rotating rectangular turn of conductor inside a magnetic field to produce alternating electric current in the external static circuit. After that in the year of 1886 J.E.H. Gordon, designed and produced first prototype of useful model. After that Lord Kelvin and Sebastian Ferranti designed a model of 100 to 300 Hz synchronous generator. Nikola Tesla in 1891, designed a commercially useful 15 KHz generator. After this year, poly phase alternators were come into picture which can deliver electric currents of multiple phases.
Use of Alternator
The power for electrical system of modern vehicles produces from alternator. In previous days, DC generators or dynamos were used for this purpose but after development of alternator, the dc dynamos are replaced by more robust and light weight alternator. Although the electrical system of motor vehicles generally requires direct electric current but still an alternator along with diode rectifier instead of a DC generator is better choice as the complicated commutation is absent here. This special type of generator which is used in vehicle is known as automotive alternator.
Another use of alternator is in diesel electric locomotive. Actually the engine of this locomotive is nothing but an alternator driven by diesel engine. The alternating electric current produced by this generator is converted to DC by integrated silicon diode rectifiers to feed all the dc traction motors. And these dc traction motors drive the wheel of the locomotive.
This machine is also used in marine similar to diesel electric locomotive. The synchronous generator used in marine is specially designed with appropriate adaptations to the salt-water environment. The typical output level of marine alternator is about 12 or 24 volt. In large marine, more than one units are used to provide large power. In this marine system the power produced by alternator is first rectified then used for charging the engine starter battery and auxiliary supply battery of marine.
Types of Alternator
Alternators or synchronous generators can be classified in may ways depending upon their application and design.
According to application these machines are classified as-
Automotive type - used in modern automobile.
Diesel electric locomotive type - used in diesel electric multiple unit.
Marine type - used in marine.
Brush less type - used in electrical power generation plant as main source of power.
Radio alternators - used for low brand radio frequency transmission.
These ac generators can be divided in many ways but we will discuss now two main types of alternator categorized according to their design. These are-
Salient pole type
It is used as low and medium speed alternator. It has a large number of projecting poles having their cores bolted or dovetailed onto a heavy magnetic wheel of cast iron or steel of good magnetic quality. Such generators are characterized by their large diameters and short axial lengths. These generator are look like big wheel. These are mainly used for low speed turbine such as in hydral power plant.
Smooth cylindrical type
It is used for steam turbine driven alternator. The rotor of this generator rotates in very high speed. The rotor consists of a smooth solid forged steel cylinder having a number of slots milled out at intervals along the outer periphery for accommodation of field coils. These rotors are designed mostly for 2 pole or 4 pole turbo generator running at 36000 rpm or 1800 rpm respectively.
posted 2 months 3 weeks ago
Transmission is the mechanism which is used to transfer the power developed by engine to the wheels of an automobile. The transmission system of an automobile includes clutch, gear box, propeller shaft axle and wheels, etc.
The term ‘Transmission’ is used for a device which is located between clutch and propeller shaft. It may be a gear box, an over drive or a torque converter, etc.
Clutch is used to engage or disengage the engine to the transmission or gear box.
When the clutch is in engaged position, the engine power or rotary motion of engine crankshaft is transmitted to gear box and then to wheels.
When clutch is disengaged, the engine power does not reach to gear box (and to wheels) although engine is running.
Clutch is also used to allow shifting or changing of gears when vehicle is running.
For shifting gears, clutch is first disengaged then gear is shifted and then clutch is engaged.
Clutch has to be disengaged to stop the vehicle and also at the time of idling.
Principle of the clutch:
It operates on the principle of friction.
When two surfaces are brought in contact and are held against each other due to friction between them, they can be used to transmit power.
If one is rotated, then other also rotates.
One surface is connected to engine and other to the transmission system of automobile
Thus, clutch is nothing but a combination of two friction surfaces.
posted 2 months 3 weeks ago
I want to unload study note for students.
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I , Tapas Banerjee try myself to upload study material for students.
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posted 4 months 1 week ago
A solid circular shoft is subjed to bending moment of 3KNm and a torque of 1KNm the shaft is to be made in carbon steel which the yielding strength tension and shear 480MPa and 265MPa respectively . Calculate diameter of shaft using distortion energy theory.
Group Data Handling Technology.
posted 5 months 5 days ago
Group data handling technology is nothing but a planning automation technology. And also the same technology GMDH streamline. At present the world famous companies are using GMDH streamline( like NASA,Honeywell). In modern times its become a vital technology for the supply chain management and smoothing. I(Eng. Aminur Rahman) am the author of the technology.
posted 8 months 4 weeks ago
A steel bar 300mm long , 24mm diameter is turned down to 18mm for 1/3 of its length, then heated to 30 degrees Celsius, clamped at both ends and allowed to cool, distance is unchanged find maximum stress in bar,temp coefficient =12.5*10 degrees Celsius, E=200GN/m square
posted 11 months 2 weeks ago
Today all we know that energy used are increased and we also knows that energy neither be created nor destroyed from energy conservation law.
So we are storing that energy in batteries and other storage devices.
There is a device all knows very well capacitor, but drawback of this is that it stores less energy. So supercapacitor are good for energy storage, because
They typically store 10 to 100 times more energy per unit volume or mass than electrolytic capacitors, can accept and deliver charge much faster than batteries, and tolerate many more charge and discharge cycles than rechargeable batteries.
Supercapacitors are used in applications requiring many rapid charge/discharge cycles rather than long term compact energy storage: within cars, buses, trains, cranes and elevators, where they are used for regenerative braking, short-term energy storage or burst-mode power delivery. Smaller units are used as memory backup for static random-access memory (SRAM).
Supercapacitors do not use the conventional solid dielectric of ordinary capacitors.